From 12a55f2db71e0a1474ba56ab1c93287600b915be Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Thu, 11 Mar 2010 10:05:50 +0000 Subject: i2c: i2c-sh_mobile register access code break out Break out register access functions in the i2c-sh_mobile driver. This update should not change any driver logic. Signed-off-by: Magnus Damm Signed-off-by: Paul Mundt --- drivers/i2c/busses/i2c-sh_mobile.c | 90 ++++++++++++++++++++++---------------- 1 file changed, 53 insertions(+), 37 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index ffb405d7c6f2..d2fabd9dbf80 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -132,12 +132,12 @@ struct sh_mobile_i2c_data { #define NORMAL_SPEED 100000 /* FAST_SPEED 400000 */ /* Register offsets */ -#define ICDR(pd) (pd->reg + 0x00) -#define ICCR(pd) (pd->reg + 0x04) -#define ICSR(pd) (pd->reg + 0x08) -#define ICIC(pd) (pd->reg + 0x0c) -#define ICCL(pd) (pd->reg + 0x10) -#define ICCH(pd) (pd->reg + 0x14) +#define ICDR 0x00 +#define ICCR 0x04 +#define ICSR 0x08 +#define ICIC 0x0c +#define ICCL 0x10 +#define ICCH 0x14 /* Register bits */ #define ICCR_ICE 0x80 @@ -160,6 +160,22 @@ struct sh_mobile_i2c_data { #define ICIC_WAITE 0x02 #define ICIC_DTEE 0x01 +static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data) +{ + iowrite8(data, pd->reg + offs); +} + +static unsigned char iic_rd(struct sh_mobile_i2c_data *pd, int offs) +{ + return ioread8(pd->reg + offs); +} + +static void iic_set_clr(struct sh_mobile_i2c_data *pd, int offs, + unsigned char set, unsigned char clr) +{ + iic_wr(pd, offs, (iic_rd(pd, offs) | set) & ~clr); +} + static void activate_ch(struct sh_mobile_i2c_data *pd) { unsigned long i2c_clk; @@ -197,24 +213,24 @@ static void activate_ch(struct sh_mobile_i2c_data *pd) pd->icch = (u_int8_t)(num/denom); /* Enable channel and configure rx ack */ - iowrite8(ioread8(ICCR(pd)) | ICCR_ICE, ICCR(pd)); + iic_set_clr(pd, ICCR, ICCR_ICE, 0); /* Mask all interrupts */ - iowrite8(0, ICIC(pd)); + iic_wr(pd, ICIC, 0); /* Set the clock */ - iowrite8(pd->iccl, ICCL(pd)); - iowrite8(pd->icch, ICCH(pd)); + iic_wr(pd, ICCL, pd->iccl); + iic_wr(pd, ICCH, pd->icch); } static void deactivate_ch(struct sh_mobile_i2c_data *pd) { /* Clear/disable interrupts */ - iowrite8(0, ICSR(pd)); - iowrite8(0, ICIC(pd)); + iic_wr(pd, ICSR, 0); + iic_wr(pd, ICIC, 0); /* Disable channel */ - iowrite8(ioread8(ICCR(pd)) & ~ICCR_ICE, ICCR(pd)); + iic_set_clr(pd, ICCR, 0, ICCR_ICE); /* Disable clock and mark device as idle */ clk_disable(pd->clk); @@ -233,35 +249,35 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd, switch (op) { case OP_START: /* issue start and trigger DTE interrupt */ - iowrite8(0x94, ICCR(pd)); + iic_wr(pd, ICCR, 0x94); break; case OP_TX_FIRST: /* disable DTE interrupt and write data */ - iowrite8(ICIC_WAITE | ICIC_ALE | ICIC_TACKE, ICIC(pd)); - iowrite8(data, ICDR(pd)); + iic_wr(pd, ICIC, ICIC_WAITE | ICIC_ALE | ICIC_TACKE); + iic_wr(pd, ICDR, data); break; case OP_TX: /* write data */ - iowrite8(data, ICDR(pd)); + iic_wr(pd, ICDR, data); break; case OP_TX_STOP: /* write data and issue a stop afterwards */ - iowrite8(data, ICDR(pd)); - iowrite8(0x90, ICCR(pd)); + iic_wr(pd, ICDR, data); + iic_wr(pd, ICCR, 0x90); break; case OP_TX_TO_RX: /* select read mode */ - iowrite8(0x81, ICCR(pd)); + iic_wr(pd, ICCR, 0x81); break; case OP_RX: /* just read data */ - ret = ioread8(ICDR(pd)); + ret = iic_rd(pd, ICDR); break; case OP_RX_STOP: /* enable DTE interrupt, issue stop */ - iowrite8(ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE, - ICIC(pd)); - iowrite8(0xc0, ICCR(pd)); + iic_wr(pd, ICIC, + ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE); + iic_wr(pd, ICCR, 0xc0); break; case OP_RX_STOP_DATA: /* enable DTE interrupt, read data, issue stop */ - iowrite8(ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE, - ICIC(pd)); - ret = ioread8(ICDR(pd)); - iowrite8(0xc0, ICCR(pd)); + iic_wr(pd, ICIC, + ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE); + ret = iic_rd(pd, ICDR); + iic_wr(pd, ICCR, 0xc0); break; } @@ -367,7 +383,7 @@ static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id) unsigned char sr; int wakeup; - sr = ioread8(ICSR(pd)); + sr = iic_rd(pd, ICSR); pd->sr |= sr; /* remember state */ dev_dbg(pd->dev, "i2c_isr 0x%02x 0x%02x %s %d %d!\n", sr, pd->sr, @@ -376,7 +392,7 @@ static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id) if (sr & (ICSR_AL | ICSR_TACK)) { /* don't interrupt transaction - continue to issue stop */ - iowrite8(sr & ~(ICSR_AL | ICSR_TACK), ICSR(pd)); + iic_wr(pd, ICSR, sr & ~(ICSR_AL | ICSR_TACK)); wakeup = 0; } else if (pd->msg->flags & I2C_M_RD) wakeup = sh_mobile_i2c_isr_rx(pd); @@ -384,7 +400,7 @@ static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id) wakeup = sh_mobile_i2c_isr_tx(pd); if (sr & ICSR_WAIT) /* TODO: add delay here to support slow acks */ - iowrite8(sr & ~ICSR_WAIT, ICSR(pd)); + iic_wr(pd, ICSR, sr & ~ICSR_WAIT); if (wakeup) { pd->sr |= SW_DONE; @@ -402,21 +418,21 @@ static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg) } /* Initialize channel registers */ - iowrite8(ioread8(ICCR(pd)) & ~ICCR_ICE, ICCR(pd)); + iic_set_clr(pd, ICCR, 0, ICCR_ICE); /* Enable channel and configure rx ack */ - iowrite8(ioread8(ICCR(pd)) | ICCR_ICE, ICCR(pd)); + iic_set_clr(pd, ICCR, ICCR_ICE, 0); /* Set the clock */ - iowrite8(pd->iccl, ICCL(pd)); - iowrite8(pd->icch, ICCH(pd)); + iic_wr(pd, ICCL, pd->iccl); + iic_wr(pd, ICCH, pd->icch); pd->msg = usr_msg; pd->pos = -1; pd->sr = 0; /* Enable all interrupts to begin with */ - iowrite8(ICIC_WAITE | ICIC_ALE | ICIC_TACKE | ICIC_DTEE, ICIC(pd)); + iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE); return 0; } @@ -451,7 +467,7 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter, retry_count = 1000; again: - val = ioread8(ICSR(pd)); + val = iic_rd(pd, ICSR); dev_dbg(pd->dev, "val 0x%02x pd->sr 0x%02x\n", val, pd->sr); -- cgit v1.2.3 From 962b6032c889ed9a5f0bdb7052d9318067a75bda Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Thu, 11 Mar 2010 10:06:02 +0000 Subject: i2c: i2c-sh_mobile support for new ICIC bits Add support for a new version of the IIC block found in the SH-Mobile ARM line of processors. Prototype patch written by Nishimoto-san. Tested on sh7377 and sh7372. Signed-off-by: NISHIMOTO Hiroki Signed-off-by: Magnus Damm Signed-off-by: Paul Mundt --- drivers/i2c/busses/i2c-sh_mobile.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index d2fabd9dbf80..598c49acaeb5 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -119,8 +119,10 @@ struct sh_mobile_i2c_data { struct i2c_adapter adap; struct clk *clk; + u_int8_t icic; u_int8_t iccl; u_int8_t icch; + u_int8_t flags; spinlock_t lock; wait_queue_head_t wait; @@ -129,6 +131,8 @@ struct sh_mobile_i2c_data { int sr; }; +#define IIC_FLAG_HAS_ICIC67 (1 << 0) + #define NORMAL_SPEED 100000 /* FAST_SPEED 400000 */ /* Register offsets */ @@ -155,6 +159,8 @@ struct sh_mobile_i2c_data { #define ICSR_WAIT 0x02 #define ICSR_DTE 0x01 +#define ICIC_ICCLB8 0x80 +#define ICIC_ICCHB8 0x40 #define ICIC_ALE 0x08 #define ICIC_TACKE 0x04 #define ICIC_WAITE 0x02 @@ -162,6 +168,9 @@ struct sh_mobile_i2c_data { static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data) { + if (offs == ICIC) + data |= pd->icic; + iowrite8(data, pd->reg + offs); } @@ -203,6 +212,14 @@ static void activate_ch(struct sh_mobile_i2c_data *pd) else pd->iccl = (u_int8_t)(num/denom); + /* one more bit of ICCL in ICIC */ + if (pd->flags & IIC_FLAG_HAS_ICIC67) { + if ((num/denom) > 0xff) + pd->icic |= ICIC_ICCLB8; + else + pd->icic &= ~ICIC_ICCLB8; + } + /* Calculate the value for icch. From the data sheet: icch = (p clock / transfer rate) * (H / (L + H)) */ num = i2c_clk * 4; @@ -212,6 +229,14 @@ static void activate_ch(struct sh_mobile_i2c_data *pd) else pd->icch = (u_int8_t)(num/denom); + /* one more bit of ICCH in ICIC */ + if (pd->flags & IIC_FLAG_HAS_ICIC67) { + if ((num/denom) > 0xff) + pd->icic |= ICIC_ICCHB8; + else + pd->icic &= ~ICIC_ICCHB8; + } + /* Enable channel and configure rx ack */ iic_set_clr(pd, ICCR, ICCR_ICE, 0); @@ -592,6 +617,12 @@ static int sh_mobile_i2c_probe(struct platform_device *dev) goto err_irq; } + /* The IIC blocks on SH-Mobile ARM processors + * come with two new bits in ICIC. + */ + if (size > 0x17) + pd->flags |= IIC_FLAG_HAS_ICIC67; + /* Enable Runtime PM for this device. * * Also tell the Runtime PM core to ignore children -- cgit v1.2.3 From 0924fada1e64f92dd89818cf3a15571cc515afd8 Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Thu, 11 Mar 2010 10:06:15 +0000 Subject: i2c: i2c-sh_mobile kconfig update for SH-Mobile ARM Update the Kconfig entry for the i2c-sh_mobile driver to enable build on SH-Mobile ARM platforms Signed-off-by: Kuninori Morimoto Signed-off-by: Magnus Damm Signed-off-by: Paul Mundt --- drivers/i2c/busses/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 9c6170cd9aac..41b0754eaf62 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -529,7 +529,7 @@ config I2C_SH7760 config I2C_SH_MOBILE tristate "SuperH Mobile I2C Controller" - depends on SUPERH + depends on SUPERH || ARCH_SHMOBILE help If you say yes to this option, support will be included for the built-in I2C interface on the Renesas SH-Mobile processor. -- cgit v1.2.3 From 9fd049927ccba1c1d0343239b82f28c4e07fb95d Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Tue, 8 Jun 2010 07:48:18 -0600 Subject: of/i2c: Generalize OF support This patch cleans up the i2c OF support code to make it selectable by all architectures and allow for automatic registration of i2c devices. Signed-off-by: Grant Likely --- drivers/i2c/busses/i2c-cpm.c | 3 ++- drivers/i2c/busses/i2c-ibm_iic.c | 3 ++- drivers/i2c/busses/i2c-mpc.c | 3 ++- 3 files changed, 6 insertions(+), 3 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c index b02b4533651d..03ae62e69596 100644 --- a/drivers/i2c/busses/i2c-cpm.c +++ b/drivers/i2c/busses/i2c-cpm.c @@ -652,6 +652,7 @@ static int __devinit cpm_i2c_probe(struct of_device *ofdev, cpm->adap = cpm_ops; i2c_set_adapdata(&cpm->adap, cpm); cpm->adap.dev.parent = &ofdev->dev; + cpm->adap.dev.of_node = of_node_get(ofdev->dev.of_node); result = cpm_i2c_setup(cpm); if (result) { @@ -679,7 +680,7 @@ static int __devinit cpm_i2c_probe(struct of_device *ofdev, /* * register OF I2C devices */ - of_register_i2c_devices(&cpm->adap, ofdev->dev.of_node); + of_i2c_register_devices(&cpm->adap); return 0; out_shut: diff --git a/drivers/i2c/busses/i2c-ibm_iic.c b/drivers/i2c/busses/i2c-ibm_iic.c index bf344135647a..d9641210dd3a 100644 --- a/drivers/i2c/busses/i2c-ibm_iic.c +++ b/drivers/i2c/busses/i2c-ibm_iic.c @@ -745,6 +745,7 @@ static int __devinit iic_probe(struct of_device *ofdev, /* Register it with i2c layer */ adap = &dev->adap; adap->dev.parent = &ofdev->dev; + adap->dev.of_node = of_node_get(np); strlcpy(adap->name, "IBM IIC", sizeof(adap->name)); i2c_set_adapdata(adap, dev); adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD; @@ -761,7 +762,7 @@ static int __devinit iic_probe(struct of_device *ofdev, dev->fast_mode ? "fast (400 kHz)" : "standard (100 kHz)"); /* Now register all the child nodes */ - of_register_i2c_devices(adap, np); + of_i2c_register_devices(adap); return 0; diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index df00eb1f11f9..d2e26d290e7a 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -600,13 +600,14 @@ static int __devinit fsl_i2c_probe(struct of_device *op, i2c->adap = mpc_ops; i2c_set_adapdata(&i2c->adap, i2c); i2c->adap.dev.parent = &op->dev; + i2c->adap.dev.of_node = of_node_get(op->dev.of_node); result = i2c_add_adapter(&i2c->adap); if (result < 0) { dev_err(i2c->dev, "failed to add adapter\n"); goto fail_add; } - of_register_i2c_devices(&i2c->adap, op->dev.of_node); + of_i2c_register_devices(&i2c->adap); return result; -- cgit v1.2.3 From 959e85f7751c33d1a2dabc5cc3fe2ed0db7052e5 Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Tue, 8 Jun 2010 07:48:19 -0600 Subject: i2c: Add OF-style registration and binding This patch adds OF hooks to the i2c core so that devices can automatically be registered based on device tree data. Signed-off-by: Grant Likely --- drivers/i2c/busses/i2c-cpm.c | 5 ----- drivers/i2c/busses/i2c-ibm_iic.c | 3 --- drivers/i2c/busses/i2c-mpc.c | 1 - drivers/i2c/i2c-core.c | 9 +++++++++ 4 files changed, 9 insertions(+), 9 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c index 03ae62e69596..e591de1bc704 100644 --- a/drivers/i2c/busses/i2c-cpm.c +++ b/drivers/i2c/busses/i2c-cpm.c @@ -677,11 +677,6 @@ static int __devinit cpm_i2c_probe(struct of_device *ofdev, dev_dbg(&ofdev->dev, "hw routines for %s registered.\n", cpm->adap.name); - /* - * register OF I2C devices - */ - of_i2c_register_devices(&cpm->adap); - return 0; out_shut: cpm_i2c_shutdown(cpm); diff --git a/drivers/i2c/busses/i2c-ibm_iic.c b/drivers/i2c/busses/i2c-ibm_iic.c index d9641210dd3a..1168d61418c9 100644 --- a/drivers/i2c/busses/i2c-ibm_iic.c +++ b/drivers/i2c/busses/i2c-ibm_iic.c @@ -761,9 +761,6 @@ static int __devinit iic_probe(struct of_device *ofdev, dev_info(&ofdev->dev, "using %s mode\n", dev->fast_mode ? "fast (400 kHz)" : "standard (100 kHz)"); - /* Now register all the child nodes */ - of_i2c_register_devices(adap); - return 0; error_cleanup: diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index d2e26d290e7a..9f7fef8c4639 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -607,7 +607,6 @@ static int __devinit fsl_i2c_probe(struct of_device *op, dev_err(i2c->dev, "failed to add adapter\n"); goto fail_add; } - of_i2c_register_devices(&i2c->adap); return result; diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 1cca2631e5b3..5588ac1fb8ad 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -30,6 +30,8 @@ #include #include #include +#include +#include #include #include #include @@ -70,6 +72,10 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv) if (!client) return 0; + /* Attempt an OF style match */ + if (of_driver_match_device(dev, drv)) + return 1; + driver = to_i2c_driver(drv); /* match on an id table if there is one */ if (driver->id_table) @@ -790,6 +796,9 @@ static int i2c_register_adapter(struct i2c_adapter *adap) if (adap->nr < __i2c_first_dynamic_bus_num) i2c_scan_static_board_info(adap); + /* Register devices from the device tree */ + of_i2c_register_devices(adap); + /* Notify drivers */ mutex_lock(&core_lock); dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, -- cgit v1.2.3 From 0c2daaafcdec726e89cbccca61d576de8429c537 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Albrecht=20Dre=C3=9F?= Date: Wed, 17 Feb 2010 08:59:14 +0000 Subject: powerpc/5200/i2c: improve i2c bus error recovery MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch improves the recovery of the MPC's I2C bus from errors like bus hangs resulting in timeouts: 1. make the bus timeout configurable, as it depends on the bus clock and the attached slave chip(s); default is still 1 second; 2. detect any of the cases indicated by the CF, BB and RXAK MSR flags if a timeout occurs, and add a missing (required) MAL reset; 3. use a more reliable method to fixup the bus if a hang has been detected. The sequence is sent 9 times which seems to be necessary if a slave "misses" more than one clock cycle. For 400 kHz bus speed, the fixup is also ~70us (81us vs. 150us) faster. Tested on a custom Lite5200b derived board, with a Dallas RTC, AD sensors and NXP IO expander chips attached to the i2c. Changes vs. v1: - use improved bus fixup sequence for all chips (not only the 5200) - calculate real clock from defaults if no clock is given in the device tree - better description (I hope) of the changes. I didn't split the changes in this file into three parts as recommended by Grant, as they actually belong together (i.e. they address one single problem, just in three places of one single source file). Signed-off-by: Albrecht Dreß [grant.likely@secretlab.ca: fixup for ->node to ->dev.of_node transition] Signed-off-by: Grant Likely --- drivers/i2c/busses/i2c-mpc.c | 69 ++++++++++++++++++++++++++++++-------------- 1 file changed, 47 insertions(+), 22 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index df00eb1f11f9..54247d475fc3 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -63,6 +63,7 @@ struct mpc_i2c { wait_queue_head_t queue; struct i2c_adapter adap; int irq; + u32 real_clk; }; struct mpc_i2c_divider { @@ -96,20 +97,23 @@ static irqreturn_t mpc_i2c_isr(int irq, void *dev_id) /* Sometimes 9th clock pulse isn't generated, and slave doesn't release * the bus, because it wants to send ACK. * Following sequence of enabling/disabling and sending start/stop generates - * the pulse, so it's all OK. + * the 9 pulses, so it's all OK. */ static void mpc_i2c_fixup(struct mpc_i2c *i2c) { - writeccr(i2c, 0); - udelay(30); - writeccr(i2c, CCR_MEN); - udelay(30); - writeccr(i2c, CCR_MSTA | CCR_MTX); - udelay(30); - writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN); - udelay(30); - writeccr(i2c, CCR_MEN); - udelay(30); + int k; + u32 delay_val = 1000000 / i2c->real_clk + 1; + + if (delay_val < 2) + delay_val = 2; + + for (k = 9; k; k--) { + writeccr(i2c, 0); + writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN); + udelay(delay_val); + writeccr(i2c, CCR_MEN); + udelay(delay_val << 1); + } } static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing) @@ -190,15 +194,18 @@ static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] __devinitconst = { }; static int __devinit mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock, - int prescaler) + int prescaler, u32 *real_clk) { const struct mpc_i2c_divider *div = NULL; unsigned int pvr = mfspr(SPRN_PVR); u32 divider; int i; - if (clock == MPC_I2C_CLOCK_LEGACY) + if (clock == MPC_I2C_CLOCK_LEGACY) { + /* see below - default fdr = 0x3f -> div = 2048 */ + *real_clk = mpc5xxx_get_bus_frequency(node) / 2048; return -EINVAL; + } /* Determine divider value */ divider = mpc5xxx_get_bus_frequency(node) / clock; @@ -216,7 +223,8 @@ static int __devinit mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock, break; } - return div ? (int)div->fdr : -EINVAL; + *real_clk = mpc5xxx_get_bus_frequency(node) / div->divider; + return (int)div->fdr; } static void __devinit mpc_i2c_setup_52xx(struct device_node *node, @@ -231,13 +239,14 @@ static void __devinit mpc_i2c_setup_52xx(struct device_node *node, return; } - ret = mpc_i2c_get_fdr_52xx(node, clock, prescaler); + ret = mpc_i2c_get_fdr_52xx(node, clock, prescaler, &i2c->real_clk); fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */ writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR); if (ret >= 0) - dev_info(i2c->dev, "clock %d Hz (fdr=%d)\n", clock, fdr); + dev_info(i2c->dev, "clock %u Hz (fdr=%d)\n", i2c->real_clk, + fdr); } #else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */ static void __devinit mpc_i2c_setup_52xx(struct device_node *node, @@ -334,14 +343,17 @@ static u32 __devinit mpc_i2c_get_sec_cfg_8xxx(void) } static int __devinit mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock, - u32 prescaler) + u32 prescaler, u32 *real_clk) { const struct mpc_i2c_divider *div = NULL; u32 divider; int i; - if (clock == MPC_I2C_CLOCK_LEGACY) + if (clock == MPC_I2C_CLOCK_LEGACY) { + /* see below - default fdr = 0x1031 -> div = 16 * 3072 */ + *real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072); return -EINVAL; + } /* Determine proper divider value */ if (of_device_is_compatible(node, "fsl,mpc8544-i2c")) @@ -364,6 +376,7 @@ static int __devinit mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock, break; } + *real_clk = fsl_get_sys_freq() / prescaler / div->divider; return div ? (int)div->fdr : -EINVAL; } @@ -380,7 +393,7 @@ static void __devinit mpc_i2c_setup_8xxx(struct device_node *node, return; } - ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler); + ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler, &i2c->real_clk); fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */ writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR); @@ -388,7 +401,7 @@ static void __devinit mpc_i2c_setup_8xxx(struct device_node *node, if (ret >= 0) dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n", - clock, fdr >> 8, fdr & 0xff); + i2c->real_clk, fdr >> 8, fdr & 0xff); } #else /* !CONFIG_FSL_SOC */ @@ -500,10 +513,14 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) return -EINTR; } if (time_after(jiffies, orig_jiffies + HZ)) { + u8 status = readb(i2c->base + MPC_I2C_SR); + dev_dbg(i2c->dev, "timeout\n"); - if (readb(i2c->base + MPC_I2C_SR) == - (CSR_MCF | CSR_MBB | CSR_RXAK)) + if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) { + writeb(status & ~CSR_MAL, + i2c->base + MPC_I2C_SR); mpc_i2c_fixup(i2c); + } return -EIO; } schedule(); @@ -595,6 +612,14 @@ static int __devinit fsl_i2c_probe(struct of_device *op, mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock, 0); } + prop = of_get_property(op->dev.of_node, "fsl,timeout", &plen); + if (prop && plen == sizeof(u32)) { + mpc_ops.timeout = *prop * HZ / 1000000; + if (mpc_ops.timeout < 5) + mpc_ops.timeout = 5; + } + dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ); + dev_set_drvdata(&op->dev, i2c); i2c->adap = mpc_ops; -- cgit v1.2.3 From 4b623926ba8e29393077fc3e01d1141a3ee2e2e9 Mon Sep 17 00:00:00 2001 From: Naveen Krishna Ch Date: Thu, 29 Jul 2010 18:49:34 +0900 Subject: ARM: SAMSUNG: i2c/busses: Add HAVE_S3C2410_I2C option to include I2C for Samsung SoCs This patch adds HAVE_S3C2410_I2C to control inclusion of I2C bus driver on Samsung SoCs and makes I2C bus driver dependency SoC specific instead of machine specific. This will enalbe all machines using Samsung ARCH_S3C2410, _S3C64XX, _S5P6440, _S5PC100, and _S5PV210 to select the I2C driver by default Signed-off-by: Naveen Krishna Ch Signed-off-by: Kukjin Kim Cc: Ben Dooks --- drivers/i2c/busses/Kconfig | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index bceafbfa7268..80143899ccec 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -521,12 +521,19 @@ config I2C_PXA_SLAVE is necessary for systems where the PXA may be a target on the I2C bus. +config HAVE_S3C2410_I2C + bool + help + This will include I2C support for Samsung SoCs. If you want to + include I2C support for any machine, kindly select this in the + respective Kconfig file. + config I2C_S3C2410 tristate "S3C2410 I2C Driver" - depends on ARCH_S3C2410 || ARCH_S3C64XX + depends on HAVE_S3C2410_I2C help Say Y here to include support for I2C controller in the - Samsung S3C2410 based System-on-Chip devices. + Samsung SoCs. config I2C_S6000 tristate "S6000 I2C support" -- cgit v1.2.3 From c6c7c729a22bfeb8e63eafce48dbaeea20e68703 Mon Sep 17 00:00:00 2001 From: Dirk Behme Date: Fri, 28 Mar 2008 06:16:12 +0100 Subject: i2c: davinci: Fix smbus Oops with AIC33 usage This fixes Oops at kernel startup while "scanning" for TLV320AIC23IDx addresses. Additional fix from Sudhakar Rajashekhara: I think 'first byte set' should come after the write because an I2C transaction is being carried out before configuring the I2C mode register (which has bits to configure Master, Start condition etc), which causes undefined behavior. Signed-off-by: Sudhakar Rajashekhara Signed-off-by: Alexander Vasiliev Signed-off-by: Brad Griffis Signed-off-by: Dirk Behme Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 4523364e6722..43913c1d50f5 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -113,6 +113,7 @@ struct davinci_i2c_dev { u8 *buf; size_t buf_len; int irq; + int stop; u8 terminate; struct i2c_adapter adapter; }; @@ -250,9 +251,6 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) u16 w; int r; - if (msg->len == 0) - return -EINVAL; - if (!pdata) pdata = &davinci_i2c_platform_data_default; /* Introduce a delay, required for some boards (e.g Davinci EVM) */ @@ -264,6 +262,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) dev->buf = msg->buf; dev->buf_len = msg->len; + dev->stop = stop; davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len); @@ -281,6 +280,10 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) flag |= DAVINCI_I2C_MDR_TRX; if (stop) flag |= DAVINCI_I2C_MDR_STP; + if (msg->len == 0) { + flag |= DAVINCI_I2C_MDR_RM; + flag &= ~DAVINCI_I2C_MDR_STP; + } /* Enable receive or transmit interrupts */ w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG); @@ -291,9 +294,21 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w); dev->terminate = 0; + /* write the data into mode register */ davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); + /* + * First byte should be set here, not after interrupt, + * because transmit-data-ready interrupt can come before + * NACK-interrupt during sending of previous message and + * ICDXR may have wrong data + */ + if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) { + davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++); + dev->buf_len--; + } + r = wait_for_completion_interruptible_timeout(&dev->cmd_complete, dev->adapter.timeout); if (r == 0) { @@ -372,7 +387,7 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) static u32 i2c_davinci_func(struct i2c_adapter *adap) { - return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; } static void terminate_read(struct davinci_i2c_dev *dev) @@ -431,6 +446,14 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) case DAVINCI_I2C_IVR_ARDY: davinci_i2c_write_reg(dev, DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY); + if (((dev->buf_len == 0) && (dev->stop != 0)) || + (dev->cmd_err & DAVINCI_I2C_STR_NACK)) { + w = davinci_i2c_read_reg(dev, + DAVINCI_I2C_MDR_REG); + w |= DAVINCI_I2C_MDR_STP; + davinci_i2c_write_reg(dev, + DAVINCI_I2C_MDR_REG, w); + } complete(&dev->cmd_complete); break; -- cgit v1.2.3 From c062a2518d35a76e7db8519b2292191a47e3ab79 Mon Sep 17 00:00:00 2001 From: Chaithrika U S Date: Wed, 6 Jan 2010 14:54:57 +0530 Subject: i2c: davinci: misc. cleanups: remove MOD_REG_BIT and IO_ADDRESS usage Cleanup the DaVinci I2C driver. Remove MOD_REG_BIT macro. Also use ioremap instead of IO_ADDRESS macro. Signed-off-by: Chaithrika U S Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 77 ++++++++++++++++++++-------------------- 1 file changed, 38 insertions(+), 39 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 43913c1d50f5..4e33909dd3f0 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -38,7 +38,6 @@ #include #include - #include /* ----- global defines ----------------------------------------------- */ @@ -72,37 +71,29 @@ #define DAVINCI_I2C_IVR_NACK 0x02 #define DAVINCI_I2C_IVR_AL 0x01 -#define DAVINCI_I2C_STR_BB (1 << 12) -#define DAVINCI_I2C_STR_RSFULL (1 << 11) -#define DAVINCI_I2C_STR_SCD (1 << 5) -#define DAVINCI_I2C_STR_ARDY (1 << 2) -#define DAVINCI_I2C_STR_NACK (1 << 1) -#define DAVINCI_I2C_STR_AL (1 << 0) - -#define DAVINCI_I2C_MDR_NACK (1 << 15) -#define DAVINCI_I2C_MDR_STT (1 << 13) -#define DAVINCI_I2C_MDR_STP (1 << 11) -#define DAVINCI_I2C_MDR_MST (1 << 10) -#define DAVINCI_I2C_MDR_TRX (1 << 9) -#define DAVINCI_I2C_MDR_XA (1 << 8) -#define DAVINCI_I2C_MDR_RM (1 << 7) -#define DAVINCI_I2C_MDR_IRS (1 << 5) - -#define DAVINCI_I2C_IMR_AAS (1 << 6) -#define DAVINCI_I2C_IMR_SCD (1 << 5) -#define DAVINCI_I2C_IMR_XRDY (1 << 4) -#define DAVINCI_I2C_IMR_RRDY (1 << 3) -#define DAVINCI_I2C_IMR_ARDY (1 << 2) -#define DAVINCI_I2C_IMR_NACK (1 << 1) -#define DAVINCI_I2C_IMR_AL (1 << 0) - -#define MOD_REG_BIT(val, mask, set) do { \ - if (set) { \ - val |= mask; \ - } else { \ - val &= ~mask; \ - } \ -} while (0) +#define DAVINCI_I2C_STR_BB BIT(12) +#define DAVINCI_I2C_STR_RSFULL BIT(11) +#define DAVINCI_I2C_STR_SCD BIT(5) +#define DAVINCI_I2C_STR_ARDY BIT(2) +#define DAVINCI_I2C_STR_NACK BIT(1) +#define DAVINCI_I2C_STR_AL BIT(0) + +#define DAVINCI_I2C_MDR_NACK BIT(15) +#define DAVINCI_I2C_MDR_STT BIT(13) +#define DAVINCI_I2C_MDR_STP BIT(11) +#define DAVINCI_I2C_MDR_MST BIT(10) +#define DAVINCI_I2C_MDR_TRX BIT(9) +#define DAVINCI_I2C_MDR_XA BIT(8) +#define DAVINCI_I2C_MDR_RM BIT(7) +#define DAVINCI_I2C_MDR_IRS BIT(5) + +#define DAVINCI_I2C_IMR_AAS BIT(6) +#define DAVINCI_I2C_IMR_SCD BIT(5) +#define DAVINCI_I2C_IMR_XRDY BIT(4) +#define DAVINCI_I2C_IMR_RRDY BIT(3) +#define DAVINCI_I2C_IMR_ARDY BIT(2) +#define DAVINCI_I2C_IMR_NACK BIT(1) +#define DAVINCI_I2C_IMR_AL BIT(0) struct davinci_i2c_dev { struct device *dev; @@ -156,7 +147,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) /* put I2C into reset */ w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - MOD_REG_BIT(w, DAVINCI_I2C_MDR_IRS, 0); + w &= ~DAVINCI_I2C_MDR_IRS; davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); /* NOTE: I2C Clock divider programming info @@ -206,7 +197,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) /* Take the I2C module out of reset: */ w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - MOD_REG_BIT(w, DAVINCI_I2C_MDR_IRS, 1); + w |= DAVINCI_I2C_MDR_IRS; davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); /* Enable interrupts */ @@ -288,9 +279,9 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) /* Enable receive or transmit interrupts */ w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG); if (msg->flags & I2C_M_RD) - MOD_REG_BIT(w, DAVINCI_I2C_IMR_RRDY, 1); + w |= DAVINCI_I2C_IMR_RRDY; else - MOD_REG_BIT(w, DAVINCI_I2C_IMR_XRDY, 1); + w |= DAVINCI_I2C_IMR_XRDY; davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w); dev->terminate = 0; @@ -349,7 +340,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) return msg->len; if (stop) { w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - MOD_REG_BIT(w, DAVINCI_I2C_MDR_STP, 1); + w |= DAVINCI_I2C_MDR_STP; davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); } return -EREMOTEIO; @@ -485,7 +476,7 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG); - MOD_REG_BIT(w, DAVINCI_I2C_IMR_XRDY, 0); + w &= ~DAVINCI_I2C_IMR_XRDY; davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w); @@ -564,7 +555,12 @@ static int davinci_i2c_probe(struct platform_device *pdev) } clk_enable(dev->clk); - dev->base = (void __iomem *)IO_ADDRESS(mem->start); + dev->base = ioremap(mem->start, resource_size(mem)); + if (!dev->base) { + r = -EBUSY; + goto err_mem_ioremap; + } + i2c_davinci_init(dev); r = request_irq(dev->irq, i2c_davinci_isr, 0, pdev->name, dev); @@ -594,6 +590,8 @@ static int davinci_i2c_probe(struct platform_device *pdev) err_free_irq: free_irq(dev->irq, dev); err_unuse_clocks: + iounmap(dev->base); +err_mem_ioremap: clk_disable(dev->clk); clk_put(dev->clk); dev->clk = NULL; @@ -622,6 +620,7 @@ static int davinci_i2c_remove(struct platform_device *pdev) davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0); free_irq(IRQ_I2C, dev); + iounmap(dev->base); kfree(dev); mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); -- cgit v1.2.3 From 5ae5b1136e0c434b076ab1f9cb39deebf6187f55 Mon Sep 17 00:00:00 2001 From: Chaithrika U S Date: Wed, 6 Jan 2010 14:54:58 +0530 Subject: i2c: davinci: Add helper functions for power management Add i2c reset control and clock divider calculation functions which will be useful for power management features. Signed-off-by: Chaithrika U S Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 56 ++++++++++++++++++++++++++-------------- 1 file changed, 37 insertions(+), 19 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 4e33909dd3f0..9afd9af4f550 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -126,12 +126,21 @@ static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg) return __raw_readw(i2c_dev->base + reg); } -/* - * This functions configures I2C and brings I2C out of reset. - * This function is called during I2C init function. This function - * also gets called if I2C encounters any errors. - */ -static int i2c_davinci_init(struct davinci_i2c_dev *dev) +static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev, + int val) +{ + u16 w; + + w = davinci_i2c_read_reg(i2c_dev, DAVINCI_I2C_MDR_REG); + if (!val) /* put I2C into reset */ + w &= ~DAVINCI_I2C_MDR_IRS; + else /* take I2C out of reset */ + w |= DAVINCI_I2C_MDR_IRS; + + davinci_i2c_write_reg(i2c_dev, DAVINCI_I2C_MDR_REG, w); +} + +static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev) { struct davinci_i2c_platform_data *pdata = dev->dev->platform_data; u16 psc; @@ -140,15 +149,6 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) u32 clkh; u32 clkl; u32 input_clock = clk_get_rate(dev->clk); - u16 w; - - if (!pdata) - pdata = &davinci_i2c_platform_data_default; - - /* put I2C into reset */ - w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - w &= ~DAVINCI_I2C_MDR_IRS; - davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); /* NOTE: I2C Clock divider programming info * As per I2C specs the following formulas provide prescaler @@ -180,12 +180,32 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh); davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl); + dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk); +} + +/* + * This function configures I2C and brings I2C out of reset. + * This function is called during I2C init function. This function + * also gets called if I2C encounters any errors. + */ +static int i2c_davinci_init(struct davinci_i2c_dev *dev) +{ + struct davinci_i2c_platform_data *pdata = dev->dev->platform_data; + + if (!pdata) + pdata = &davinci_i2c_platform_data_default; + + /* put I2C into reset */ + davinci_i2c_reset_ctrl(dev, 0); + + /* compute clock dividers */ + i2c_davinci_calc_clk_dividers(dev); + /* Respond at reserved "SMBus Host" slave address" (and zero); * we seem to have no option to not respond... */ davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, 0x08); - dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk); dev_dbg(dev->dev, "PSC = %d\n", davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG)); dev_dbg(dev->dev, "CLKL = %d\n", @@ -196,9 +216,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) pdata->bus_freq, pdata->bus_delay); /* Take the I2C module out of reset: */ - w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - w |= DAVINCI_I2C_MDR_IRS; - davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); + davinci_i2c_reset_ctrl(dev, 1); /* Enable interrupts */ davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, I2C_DAVINCI_INTR_ALL); -- cgit v1.2.3 From 68f15de976f8f90d3bc0d10160aa20b0528760d4 Mon Sep 17 00:00:00 2001 From: Chaithrika U S Date: Wed, 6 Jan 2010 14:54:59 +0530 Subject: i2c: davinci: Add suspend/resume support Add suspend and resume callbacks to DaVinci I2C driver. This has been tested on DA850/OMAP-L138 EVM. Signed-off-by: Chaithrika U S Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 9afd9af4f550..7afeb28d6d76 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -646,6 +646,41 @@ static int davinci_i2c_remove(struct platform_device *pdev) return 0; } +#ifdef CONFIG_PM +static int davinci_i2c_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev); + + /* put I2C into reset */ + davinci_i2c_reset_ctrl(i2c_dev, 0); + clk_disable(i2c_dev->clk); + + return 0; +} + +static int davinci_i2c_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev); + + clk_enable(i2c_dev->clk); + /* take I2C out of reset */ + davinci_i2c_reset_ctrl(i2c_dev, 1); + + return 0; +} + +static const struct dev_pm_ops davinci_i2c_pm = { + .suspend = davinci_i2c_suspend, + .resume = davinci_i2c_resume, +}; + +#define davinci_i2c_pm_ops (&davinci_i2c_pm) +#else +#define davinci_i2c_pm_ops NULL +#endif + /* work with hotplug and coldplug */ MODULE_ALIAS("platform:i2c_davinci"); @@ -655,6 +690,7 @@ static struct platform_driver davinci_i2c_driver = { .driver = { .name = "i2c_davinci", .owner = THIS_MODULE, + .pm = davinci_i2c_pm_ops, }, }; -- cgit v1.2.3 From 82c0de11b734c5acec13c0f6007466da81cd16d9 Mon Sep 17 00:00:00 2001 From: Chaithrika U S Date: Wed, 6 Jan 2010 14:55:00 +0530 Subject: i2c: davinci: Add cpufreq support Add cpufreq support for DaVinci I2C driver. Tested on DA850/OMAP-L138 EVM. Signed-off-by: Chaithrika U S Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 63 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 7afeb28d6d76..352b4e7bdd9e 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include @@ -107,6 +108,10 @@ struct davinci_i2c_dev { int stop; u8 terminate; struct i2c_adapter adapter; +#ifdef CONFIG_CPU_FREQ + struct completion xfr_complete; + struct notifier_block freq_transition; +#endif }; /* default platform data to use if not supplied in the platform_device */ @@ -391,6 +396,11 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) if (ret < 0) return ret; } + +#ifdef CONFIG_CPU_FREQ + complete(&dev->xfr_complete); +#endif + return num; } @@ -523,6 +533,48 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) return count ? IRQ_HANDLED : IRQ_NONE; } +#ifdef CONFIG_CPU_FREQ +static int i2c_davinci_cpufreq_transition(struct notifier_block *nb, + unsigned long val, void *data) +{ + struct davinci_i2c_dev *dev; + + dev = container_of(nb, struct davinci_i2c_dev, freq_transition); + if (val == CPUFREQ_PRECHANGE) { + wait_for_completion(&dev->xfr_complete); + davinci_i2c_reset_ctrl(dev, 0); + } else if (val == CPUFREQ_POSTCHANGE) { + i2c_davinci_calc_clk_dividers(dev); + davinci_i2c_reset_ctrl(dev, 1); + } + + return 0; +} + +static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev) +{ + dev->freq_transition.notifier_call = i2c_davinci_cpufreq_transition; + + return cpufreq_register_notifier(&dev->freq_transition, + CPUFREQ_TRANSITION_NOTIFIER); +} + +static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev) +{ + cpufreq_unregister_notifier(&dev->freq_transition, + CPUFREQ_TRANSITION_NOTIFIER); +} +#else +static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev) +{ + return 0; +} + +static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev) +{ +} +#endif + static struct i2c_algorithm i2c_davinci_algo = { .master_xfer = i2c_davinci_xfer, .functionality = i2c_davinci_func, @@ -562,6 +614,9 @@ static int davinci_i2c_probe(struct platform_device *pdev) } init_completion(&dev->cmd_complete); +#ifdef CONFIG_CPU_FREQ + init_completion(&dev->xfr_complete); +#endif dev->dev = get_device(&pdev->dev); dev->irq = irq->start; platform_set_drvdata(pdev, dev); @@ -587,6 +642,12 @@ static int davinci_i2c_probe(struct platform_device *pdev) goto err_unuse_clocks; } + r = i2c_davinci_cpufreq_register(dev); + if (r) { + dev_err(&pdev->dev, "failed to register cpufreq\n"); + goto err_free_irq; + } + adap = &dev->adapter; i2c_set_adapdata(adap, dev); adap->owner = THIS_MODULE; @@ -628,6 +689,8 @@ static int davinci_i2c_remove(struct platform_device *pdev) struct davinci_i2c_dev *dev = platform_get_drvdata(pdev); struct resource *mem; + i2c_davinci_cpufreq_deregister(dev); + platform_set_drvdata(pdev, NULL); i2c_del_adapter(&dev->adapter); put_device(&pdev->dev); -- cgit v1.2.3 From 8574faf9a5ae71fdd84c6413779a9b076138eb9e Mon Sep 17 00:00:00 2001 From: Philby John Date: Mon, 11 Jan 2010 22:39:44 +0530 Subject: i2c: davinci: bus recovery procedure to clear the bus Come out of i2c time out condition by following the bus recovery procedure outlined in the i2c protocol v3 spec. The kernel must be robust enough to gracefully recover from i2c bus failure without having to reset the machine. This is done by first NACKing the slave, pulsing the SCL line 9 times and then sending the stop command. This patch has been tested on a DM6446 and DM355 Signed-off-by: Philby John Signed-off-by: Srinivasan, Nageswari Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 57 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 53 insertions(+), 4 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 352b4e7bdd9e..2222c87876b9 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include @@ -44,6 +45,7 @@ /* ----- global defines ----------------------------------------------- */ #define DAVINCI_I2C_TIMEOUT (1*HZ) +#define DAVINCI_I2C_MAX_TRIES 2 #define I2C_DAVINCI_INTR_ALL (DAVINCI_I2C_IMR_AAS | \ DAVINCI_I2C_IMR_SCD | \ DAVINCI_I2C_IMR_ARDY | \ @@ -131,6 +133,44 @@ static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg) return __raw_readw(i2c_dev->base + reg); } +/* Generate a pulse on the i2c clock pin. */ +static void generic_i2c_clock_pulse(unsigned int scl_pin) +{ + u16 i; + + if (scl_pin) { + /* Send high and low on the SCL line */ + for (i = 0; i < 9; i++) { + gpio_set_value(scl_pin, 0); + udelay(20); + gpio_set_value(scl_pin, 1); + udelay(20); + } + } +} + +/* This routine does i2c bus recovery as specified in the + * i2c protocol Rev. 03 section 3.16 titled "Bus clear" + */ +static void i2c_recover_bus(struct davinci_i2c_dev *dev) +{ + u32 flag = 0; + struct davinci_i2c_platform_data *pdata = dev->dev->platform_data; + + dev_err(dev->dev, "initiating i2c bus recovery\n"); + /* Send NACK to the slave */ + flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); + flag |= DAVINCI_I2C_MDR_NACK; + /* write the data into mode register */ + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); + if (pdata) + generic_i2c_clock_pulse(pdata->scl_pin); + /* Send STOP */ + flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); + flag |= DAVINCI_I2C_MDR_STP; + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); +} + static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev, int val) { @@ -236,14 +276,22 @@ static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev, char allow_sleep) { unsigned long timeout; + static u16 to_cnt; timeout = jiffies + dev->adapter.timeout; while (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB) { - if (time_after(jiffies, timeout)) { - dev_warn(dev->dev, - "timeout waiting for bus ready\n"); - return -ETIMEDOUT; + if (to_cnt <= DAVINCI_I2C_MAX_TRIES) { + if (time_after(jiffies, timeout)) { + dev_warn(dev->dev, + "timeout waiting for bus ready\n"); + to_cnt++; + return -ETIMEDOUT; + } else { + to_cnt = 0; + i2c_recover_bus(dev); + i2c_davinci_init(dev); + } } if (allow_sleep) schedule_timeout(1); @@ -327,6 +375,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) dev->adapter.timeout); if (r == 0) { dev_err(dev->dev, "controller timed out\n"); + i2c_recover_bus(dev); i2c_davinci_init(dev); dev->buf_len = 0; return -ETIMEDOUT; -- cgit v1.2.3 From 2dc11581376829303b98eadb2de253bee065a56a Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Fri, 6 Aug 2010 09:25:50 -0600 Subject: of/device: Replace struct of_device with struct platform_device of_device is just an alias for platform_device, so remove it entirely. Also replace to_of_device() with to_platform_device() and update comment blocks. This patch was initially generated from the following semantic patch, and then edited by hand to pick up the bits that coccinelle didn't catch. @@ @@ -struct of_device +struct platform_device Signed-off-by: Grant Likely Reviewed-by: David S. Miller --- drivers/i2c/busses/i2c-cpm.c | 8 ++++---- drivers/i2c/busses/i2c-ibm_iic.c | 6 +++--- drivers/i2c/busses/i2c-mpc.c | 4 ++-- 3 files changed, 9 insertions(+), 9 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c index e591de1bc704..f7bd2613cecc 100644 --- a/drivers/i2c/busses/i2c-cpm.c +++ b/drivers/i2c/busses/i2c-cpm.c @@ -105,7 +105,7 @@ struct i2c_reg { struct cpm_i2c { char *base; - struct of_device *ofdev; + struct platform_device *ofdev; struct i2c_adapter adap; uint dp_addr; int version; /* CPM1=1, CPM2=2 */ @@ -428,7 +428,7 @@ static const struct i2c_adapter cpm_ops = { static int __devinit cpm_i2c_setup(struct cpm_i2c *cpm) { - struct of_device *ofdev = cpm->ofdev; + struct platform_device *ofdev = cpm->ofdev; const u32 *data; int len, ret, i; void __iomem *i2c_base; @@ -634,7 +634,7 @@ static void cpm_i2c_shutdown(struct cpm_i2c *cpm) cpm_muram_free(cpm->i2c_addr); } -static int __devinit cpm_i2c_probe(struct of_device *ofdev, +static int __devinit cpm_i2c_probe(struct platform_device *ofdev, const struct of_device_id *match) { int result, len; @@ -687,7 +687,7 @@ out_free: return result; } -static int __devexit cpm_i2c_remove(struct of_device *ofdev) +static int __devexit cpm_i2c_remove(struct platform_device *ofdev) { struct cpm_i2c *cpm = dev_get_drvdata(&ofdev->dev); diff --git a/drivers/i2c/busses/i2c-ibm_iic.c b/drivers/i2c/busses/i2c-ibm_iic.c index 1168d61418c9..43ca32fddde2 100644 --- a/drivers/i2c/busses/i2c-ibm_iic.c +++ b/drivers/i2c/busses/i2c-ibm_iic.c @@ -661,7 +661,7 @@ static inline u8 iic_clckdiv(unsigned int opb) return (u8)((opb + 9) / 10 - 1); } -static int __devinit iic_request_irq(struct of_device *ofdev, +static int __devinit iic_request_irq(struct platform_device *ofdev, struct ibm_iic_private *dev) { struct device_node *np = ofdev->dev.of_node; @@ -692,7 +692,7 @@ static int __devinit iic_request_irq(struct of_device *ofdev, /* * Register single IIC interface */ -static int __devinit iic_probe(struct of_device *ofdev, +static int __devinit iic_probe(struct platform_device *ofdev, const struct of_device_id *match) { struct device_node *np = ofdev->dev.of_node; @@ -780,7 +780,7 @@ error_cleanup: /* * Cleanup initialized IIC interface */ -static int __devexit iic_remove(struct of_device *ofdev) +static int __devexit iic_remove(struct platform_device *ofdev) { struct ibm_iic_private *dev = dev_get_drvdata(&ofdev->dev); diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index 6545d1c99b61..a1c419a716af 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -560,7 +560,7 @@ static struct i2c_adapter mpc_ops = { .timeout = HZ, }; -static int __devinit fsl_i2c_probe(struct of_device *op, +static int __devinit fsl_i2c_probe(struct platform_device *op, const struct of_device_id *match) { struct mpc_i2c *i2c; @@ -646,7 +646,7 @@ static int __devinit fsl_i2c_probe(struct of_device *op, return result; }; -static int __devexit fsl_i2c_remove(struct of_device *op) +static int __devexit fsl_i2c_remove(struct platform_device *op) { struct mpc_i2c *i2c = dev_get_drvdata(&op->dev); -- cgit v1.2.3 From 21e2ecfe19df8f28408b5a607fef8704f51fa7f8 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Tue, 15 Jun 2010 10:56:45 +0200 Subject: i2c-pxa: fix compiler warning, due to missing const This patch adds the missing const to "struct platform_device_id" to fix this warning: /home/frogger/pengutronix/linux/linux-2.6/drivers/i2c/busses/i2c-pxa.c: In function 'i2c_pxa_probe': /home/frogger/pengutronix/linux/linux-2.6/drivers/i2c/busses/i2c-pxa.c:1004: warning: initialization discards qualifiers from pointer target type Signed-off-by: Marc Kleine-Budde Cc: Eric Miao Cc: Roel Kluin Cc: Pavel Machek Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-pxa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c index 020ff23d762f..c94e51b2651e 100644 --- a/drivers/i2c/busses/i2c-pxa.c +++ b/drivers/i2c/busses/i2c-pxa.c @@ -1001,7 +1001,7 @@ static int i2c_pxa_probe(struct platform_device *dev) struct pxa_i2c *i2c; struct resource *res; struct i2c_pxa_platform_data *plat = dev->dev.platform_data; - struct platform_device_id *id = platform_get_device_id(dev); + const struct platform_device_id *id = platform_get_device_id(dev); int ret; int irq; -- cgit v1.2.3 From c115167aef64717fb6b81cde957853ef16dd9551 Mon Sep 17 00:00:00 2001 From: Kevin Wells Date: Thu, 5 Aug 2010 15:40:17 -0700 Subject: i2c: Enable NXP LPC support in Kconfig NXP LPC series processors use the IP3204 I2C block shared with the Philips PNX4008 processor. Signed-off-by: Kevin Wells Signed-off-by: Ben Dooks --- drivers/i2c/busses/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index bceafbfa7268..77eabae4df8a 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -496,8 +496,8 @@ config I2C_PMCMSP will be called i2c-pmcmsp. config I2C_PNX - tristate "I2C bus support for Philips PNX targets" - depends on ARCH_PNX4008 + tristate "I2C bus support for Philips PNX and NXP LPC targets" + depends on ARCH_PNX4008 || ARCH_LPC32XX help This driver supports the Philips IP3204 I2C IP block master and/or slave controller -- cgit v1.2.3 From ededad3e6f2c7ccf0c721e71f2fd7b1ea56f520f Mon Sep 17 00:00:00 2001 From: Wan ZongShun Date: Fri, 25 Jun 2010 13:43:07 +0800 Subject: i2c/nuc900: add i2c driver support for nuc900 This patch is to add i2c driver support for nuc900. Signed-off-by: Wan ZongShun Reviewed-by: Marek Vasut Reviewed-by: Baruch Siach Signed-off-by: Ben Dooks --- drivers/i2c/busses/Kconfig | 7 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-nuc900.c | 709 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 717 insertions(+) create mode 100644 drivers/i2c/busses/i2c-nuc900.c (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index bceafbfa7268..ee284d2f74fd 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -448,6 +448,13 @@ config I2C_NOMADIK If you say yes to this option, support will be included for the I2C interface from ST-Ericsson's Nomadik and Ux500 architectures. +config I2C_NUC900 + tristate "NUC900 I2C Driver" + depends on ARCH_W90X900 + help + Say Y here to include support for I2C controller in the + Winbond/Nuvoton NUC900 based System-on-Chip devices. + config I2C_OCORES tristate "OpenCores I2C Controller" depends on EXPERIMENTAL diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 936880bd1dc5..c3ef49230cba 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -43,6 +43,7 @@ obj-$(CONFIG_I2C_IXP2000) += i2c-ixp2000.o obj-$(CONFIG_I2C_MPC) += i2c-mpc.o obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o obj-$(CONFIG_I2C_NOMADIK) += i2c-nomadik.o +obj-$(CONFIG_I2C_NUC900) += i2c-nuc900.o obj-$(CONFIG_I2C_OCORES) += i2c-ocores.o obj-$(CONFIG_I2C_OMAP) += i2c-omap.o obj-$(CONFIG_I2C_PASEMI) += i2c-pasemi.o diff --git a/drivers/i2c/busses/i2c-nuc900.c b/drivers/i2c/busses/i2c-nuc900.c new file mode 100644 index 000000000000..92d770d7bbc2 --- /dev/null +++ b/drivers/i2c/busses/i2c-nuc900.c @@ -0,0 +1,709 @@ +/* + * linux/drivers/i2c/busses/i2c-nuc900.c + * + * Copyright (c) 2010 Nuvoton technology corporation. + * + * This driver based on S3C2410 I2C driver of Ben Dooks . + * Written by Wan ZongShun + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation;version 2 of the License. + * + */ + +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +/* nuc900 i2c registers offset */ + +#define CSR 0x00 +#define DIVIDER 0x04 +#define CMDR 0x08 +#define SWR 0x0C +#define RXR 0x10 +#define TXR 0x14 + +/* nuc900 i2c CSR register bits */ + +#define IRQEN 0x003 +#define I2CBUSY 0x400 +#define I2CSTART 0x018 +#define IRQFLAG 0x004 +#define ARBIT_LOST 0x200 +#define SLAVE_ACK 0x800 + +/* nuc900 i2c CMDR register bits */ + +#define I2C_CMD_START 0x10 +#define I2C_CMD_STOP 0x08 +#define I2C_CMD_READ 0x04 +#define I2C_CMD_WRITE 0x02 +#define I2C_CMD_NACK 0x01 + +/* i2c controller state */ + +enum nuc900_i2c_state { + STATE_IDLE, + STATE_START, + STATE_READ, + STATE_WRITE, + STATE_STOP +}; + +/* i2c controller private data */ + +struct nuc900_i2c { + spinlock_t lock; + wait_queue_head_t wait; + + struct i2c_msg *msg; + unsigned int msg_num; + unsigned int msg_idx; + unsigned int msg_ptr; + unsigned int irq; + + enum nuc900_i2c_state state; + + void __iomem *regs; + struct clk *clk; + struct device *dev; + struct resource *ioarea; + struct i2c_adapter adap; +}; + +/* nuc900_i2c_master_complete + * + * complete the message and wake up the caller, using the given return code, + * or zero to mean ok. +*/ + +static inline void nuc900_i2c_master_complete(struct nuc900_i2c *i2c, int ret) +{ + dev_dbg(i2c->dev, "master_complete %d\n", ret); + + i2c->msg_ptr = 0; + i2c->msg = NULL; + i2c->msg_idx++; + i2c->msg_num = 0; + if (ret) + i2c->msg_idx = ret; + + wake_up(&i2c->wait); +} + +/* irq enable/disable functions */ + +static inline void nuc900_i2c_disable_irq(struct nuc900_i2c *i2c) +{ + unsigned long tmp; + + tmp = readl(i2c->regs + CSR); + writel(tmp & ~IRQEN, i2c->regs + CSR); +} + +static inline void nuc900_i2c_enable_irq(struct nuc900_i2c *i2c) +{ + unsigned long tmp; + + tmp = readl(i2c->regs + CSR); + writel(tmp | IRQEN, i2c->regs + CSR); +} + + +/* nuc900_i2c_message_start + * + * put the start of a message onto the bus +*/ + +static void nuc900_i2c_message_start(struct nuc900_i2c *i2c, + struct i2c_msg *msg) +{ + unsigned int addr = (msg->addr & 0x7f) << 1; + + if (msg->flags & I2C_M_RD) + addr |= 0x1; + writel(addr & 0xff, i2c->regs + TXR); + writel(I2C_CMD_START | I2C_CMD_WRITE, i2c->regs + CMDR); +} + +static inline void nuc900_i2c_stop(struct nuc900_i2c *i2c, int ret) +{ + + dev_dbg(i2c->dev, "STOP\n"); + + /* stop the transfer */ + i2c->state = STATE_STOP; + writel(I2C_CMD_STOP, i2c->regs + CMDR); + + nuc900_i2c_master_complete(i2c, ret); + nuc900_i2c_disable_irq(i2c); +} + +/* helper functions to determine the current state in the set of + * messages we are sending +*/ + +/* is_lastmsg() + * + * returns TRUE if the current message is the last in the set +*/ + +static inline int is_lastmsg(struct nuc900_i2c *i2c) +{ + return i2c->msg_idx >= (i2c->msg_num - 1); +} + +/* is_msglast + * + * returns TRUE if we this is the last byte in the current message +*/ + +static inline int is_msglast(struct nuc900_i2c *i2c) +{ + return i2c->msg_ptr == i2c->msg->len-1; +} + +/* is_msgend + * + * returns TRUE if we reached the end of the current message +*/ + +static inline int is_msgend(struct nuc900_i2c *i2c) +{ + return i2c->msg_ptr >= i2c->msg->len; +} + +/* i2c_nuc900_irq_nextbyte + * + * process an interrupt and work out what to do + */ + +static void i2c_nuc900_irq_nextbyte(struct nuc900_i2c *i2c, + unsigned long iicstat) +{ + unsigned char byte; + + switch (i2c->state) { + + case STATE_IDLE: + dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __func__); + break; + + case STATE_STOP: + dev_err(i2c->dev, "%s: called in STATE_STOP\n", __func__); + nuc900_i2c_disable_irq(i2c); + break; + + case STATE_START: + /* last thing we did was send a start condition on the + * bus, or started a new i2c message + */ + + if (iicstat & SLAVE_ACK && + !(i2c->msg->flags & I2C_M_IGNORE_NAK)) { + /* ack was not received... */ + + dev_dbg(i2c->dev, "ack was not received\n"); + nuc900_i2c_stop(i2c, -ENXIO); + break; + } + + if (i2c->msg->flags & I2C_M_RD) + i2c->state = STATE_READ; + else + i2c->state = STATE_WRITE; + + /* terminate the transfer if there is nothing to do + * as this is used by the i2c probe to find devices. + */ + + if (is_lastmsg(i2c) && i2c->msg->len == 0) { + nuc900_i2c_stop(i2c, 0); + break; + } + + if (i2c->state == STATE_READ) + goto prepare_read; + + /* fall through to the write state, as we will need to + * send a byte as well + */ + + case STATE_WRITE: + /* we are writing data to the device... check for the + * end of the message, and if so, work out what to do + */ + + if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) { + if (iicstat & SLAVE_ACK) { + dev_dbg(i2c->dev, "WRITE: No Ack\n"); + + nuc900_i2c_stop(i2c, -ECONNREFUSED); + break; + } + } + +retry_write: + + if (!is_msgend(i2c)) { + byte = i2c->msg->buf[i2c->msg_ptr++]; + writeb(byte, i2c->regs + TXR); + writel(I2C_CMD_WRITE, i2c->regs + CMDR); + + } else if (!is_lastmsg(i2c)) { + /* we need to go to the next i2c message */ + + dev_dbg(i2c->dev, "WRITE: Next Message\n"); + + i2c->msg_ptr = 0; + i2c->msg_idx++; + i2c->msg++; + + /* check to see if we need to do another message */ + if (i2c->msg->flags & I2C_M_NOSTART) { + + if (i2c->msg->flags & I2C_M_RD) { + /* cannot do this, the controller + * forces us to send a new START + * when we change direction + */ + + nuc900_i2c_stop(i2c, -EINVAL); + } + + goto retry_write; + } else { + /* send the new start */ + nuc900_i2c_message_start(i2c, i2c->msg); + i2c->state = STATE_START; + } + + } else { + /* send stop */ + + nuc900_i2c_stop(i2c, 0); + } + break; + + case STATE_READ: + /* we have a byte of data in the data register, do + * something with it, and then work out wether we are + * going to do any more read/write + */ + + byte = readb(i2c->regs + RXR); + i2c->msg->buf[i2c->msg_ptr++] = byte; + +prepare_read: + if (is_msglast(i2c)) { + /* last byte of buffer */ + + if (is_lastmsg(i2c)) + writel(I2C_CMD_READ | I2C_CMD_NACK, + i2c->regs + CMDR); + + } else if (is_msgend(i2c)) { + /* ok, we've read the entire buffer, see if there + * is anything else we need to do + */ + + if (is_lastmsg(i2c)) { + /* last message, send stop and complete */ + dev_dbg(i2c->dev, "READ: Send Stop\n"); + + nuc900_i2c_stop(i2c, 0); + } else { + /* go to the next transfer */ + dev_dbg(i2c->dev, "READ: Next Transfer\n"); + + i2c->msg_ptr = 0; + i2c->msg_idx++; + i2c->msg++; + + writel(I2C_CMD_READ, i2c->regs + CMDR); + } + + } else { + writel(I2C_CMD_READ, i2c->regs + CMDR); + } + + break; + } +} + +/* nuc900_i2c_irq + * + * top level IRQ servicing routine +*/ + +static irqreturn_t nuc900_i2c_irq(int irqno, void *dev_id) +{ + struct nuc900_i2c *i2c = dev_id; + unsigned long status; + + status = readl(i2c->regs + CSR); + writel(status | IRQFLAG, i2c->regs + CSR); + + if (status & ARBIT_LOST) { + /* deal with arbitration loss */ + dev_err(i2c->dev, "deal with arbitration loss\n"); + goto out; + } + + if (i2c->state == STATE_IDLE) { + dev_dbg(i2c->dev, "IRQ: error i2c->state == IDLE\n"); + goto out; + } + + /* pretty much this leaves us with the fact that we've + * transmitted or received whatever byte we last sent + */ + + i2c_nuc900_irq_nextbyte(i2c, status); + + out: + return IRQ_HANDLED; +} + + +/* nuc900_i2c_set_master + * + * get the i2c bus for a master transaction +*/ + +static int nuc900_i2c_set_master(struct nuc900_i2c *i2c) +{ + int timeout = 400; + + while (timeout-- > 0) { + if (((readl(i2c->regs + SWR) & I2CSTART) == I2CSTART) && + ((readl(i2c->regs + CSR) & I2CBUSY) == 0)) { + return 0; + } + + msleep(1); + } + + return -ETIMEDOUT; +} + +/* nuc900_i2c_doxfer + * + * this starts an i2c transfer +*/ + +static int nuc900_i2c_doxfer(struct nuc900_i2c *i2c, + struct i2c_msg *msgs, int num) +{ + unsigned long iicstat, timeout; + int spins = 20; + int ret; + + ret = nuc900_i2c_set_master(i2c); + if (ret != 0) { + dev_err(i2c->dev, "cannot get bus (error %d)\n", ret); + ret = -EAGAIN; + goto out; + } + + spin_lock_irq(&i2c->lock); + + i2c->msg = msgs; + i2c->msg_num = num; + i2c->msg_ptr = 0; + i2c->msg_idx = 0; + i2c->state = STATE_START; + + nuc900_i2c_message_start(i2c, msgs); + spin_unlock_irq(&i2c->lock); + + timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5); + + ret = i2c->msg_idx; + + /* having these next two as dev_err() makes life very + * noisy when doing an i2cdetect + */ + + if (timeout == 0) + dev_dbg(i2c->dev, "timeout\n"); + else if (ret != num) + dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret); + + /* ensure the stop has been through the bus */ + + dev_dbg(i2c->dev, "waiting for bus idle\n"); + + /* first, try busy waiting briefly */ + do { + iicstat = readl(i2c->regs + CSR); + } while ((iicstat & I2CBUSY) && --spins); + + /* if that timed out sleep */ + if (!spins) { + msleep(1); + iicstat = readl(i2c->regs + CSR); + } + + if (iicstat & I2CBUSY) + dev_warn(i2c->dev, "timeout waiting for bus idle\n"); + + out: + return ret; +} + +/* nuc900_i2c_xfer + * + * first port of call from the i2c bus code when an message needs + * transferring across the i2c bus. +*/ + +static int nuc900_i2c_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + struct nuc900_i2c *i2c = (struct nuc900_i2c *)adap->algo_data; + int retry; + int ret; + + nuc900_i2c_enable_irq(i2c); + + for (retry = 0; retry < adap->retries; retry++) { + + ret = nuc900_i2c_doxfer(i2c, msgs, num); + + if (ret != -EAGAIN) + return ret; + + dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry); + + udelay(100); + } + + return -EREMOTEIO; +} + +/* declare our i2c functionality */ +static u32 nuc900_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING; +} + +/* i2c bus registration info */ + +static const struct i2c_algorithm nuc900_i2c_algorithm = { + .master_xfer = nuc900_i2c_xfer, + .functionality = nuc900_i2c_func, +}; + +/* nuc900_i2c_probe + * + * called by the bus driver when a suitable device is found +*/ + +static int __devinit nuc900_i2c_probe(struct platform_device *pdev) +{ + struct nuc900_i2c *i2c; + struct nuc900_platform_i2c *pdata; + struct resource *res; + int ret; + + pdata = pdev->dev.platform_data; + if (!pdata) { + dev_err(&pdev->dev, "no platform data\n"); + return -EINVAL; + } + + i2c = kzalloc(sizeof(struct nuc900_i2c), GFP_KERNEL); + if (!i2c) { + dev_err(&pdev->dev, "no memory for state\n"); + return -ENOMEM; + } + + strlcpy(i2c->adap.name, "nuc900-i2c0", sizeof(i2c->adap.name)); + i2c->adap.owner = THIS_MODULE; + i2c->adap.algo = &nuc900_i2c_algorithm; + i2c->adap.retries = 2; + i2c->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD; + + spin_lock_init(&i2c->lock); + init_waitqueue_head(&i2c->wait); + + /* find the clock and enable it */ + + i2c->dev = &pdev->dev; + i2c->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(i2c->clk)) { + dev_err(&pdev->dev, "cannot get clock\n"); + ret = -ENOENT; + goto err_noclk; + } + + dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk); + + clk_enable(i2c->clk); + + /* map the registers */ + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (res == NULL) { + dev_err(&pdev->dev, "cannot find IO resource\n"); + ret = -ENOENT; + goto err_clk; + } + + i2c->ioarea = request_mem_region(res->start, resource_size(res), + pdev->name); + + if (i2c->ioarea == NULL) { + dev_err(&pdev->dev, "cannot request IO\n"); + ret = -ENXIO; + goto err_clk; + } + + i2c->regs = ioremap(res->start, resource_size(res)); + + if (i2c->regs == NULL) { + dev_err(&pdev->dev, "cannot map IO\n"); + ret = -ENXIO; + goto err_ioarea; + } + + dev_dbg(&pdev->dev, "registers %p (%p, %p)\n", + i2c->regs, i2c->ioarea, res); + + /* setup info block for the i2c core */ + + i2c->adap.algo_data = i2c; + i2c->adap.dev.parent = &pdev->dev; + + mfp_set_groupg(&pdev->dev); + + clk_get_rate(i2c->clk); + + ret = (i2c->clk.apbfreq)/(pdata->bus_freq * 5) - 1; + writel(ret & 0xffff, i2c->regs + DIVIDER); + + /* find the IRQ for this unit (note, this relies on the init call to + * ensure no current IRQs pending + */ + + i2c->irq = ret = platform_get_irq(pdev, 0); + if (ret <= 0) { + dev_err(&pdev->dev, "cannot find IRQ\n"); + goto err_iomap; + } + + ret = request_irq(i2c->irq, nuc900_i2c_irq, IRQF_DISABLED | IRQF_SHARED, + dev_name(&pdev->dev), i2c); + + if (ret != 0) { + dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq); + goto err_iomap; + } + + /* Note, previous versions of the driver used i2c_add_adapter() + * to add the bus at any number. We now pass the bus number via + * the platform data, so if unset it will now default to always + * being bus 0. + */ + + i2c->adap.nr = pdata->bus_num; + + ret = i2c_add_numbered_adapter(&i2c->adap); + if (ret < 0) { + dev_err(&pdev->dev, "failed to add bus to i2c core\n"); + goto err_irq; + } + + platform_set_drvdata(pdev, i2c); + + dev_info(&pdev->dev, "%s: NUC900 I2C adapter\n", + dev_name(&i2c->adap.dev)); + return 0; + + err_irq: + free_irq(i2c->irq, i2c); + + err_iomap: + iounmap(i2c->regs); + + err_ioarea: + release_resource(i2c->ioarea); + kfree(i2c->ioarea); + + err_clk: + clk_disable(i2c->clk); + clk_put(i2c->clk); + + err_noclk: + kfree(i2c); + return ret; +} + +/* nuc900_i2c_remove + * + * called when device is removed from the bus +*/ + +static int __devexit nuc900_i2c_remove(struct platform_device *pdev) +{ + struct nuc900_i2c *i2c = platform_get_drvdata(pdev); + + i2c_del_adapter(&i2c->adap); + free_irq(i2c->irq, i2c); + + clk_disable(i2c->clk); + clk_put(i2c->clk); + + iounmap(i2c->regs); + + release_resource(i2c->ioarea); + kfree(i2c->ioarea); + kfree(i2c); + + return 0; +} + +static struct platform_driver nuc900_i2c_driver = { + .probe = nuc900_i2c_probe, + .remove = __devexit_p(nuc900_i2c_remove), + .driver = { + .owner = THIS_MODULE, + .name = "nuc900-i2c0", + }, +}; + +static int __init i2c_adap_nuc900_init(void) +{ + return platform_driver_register(&nuc900_i2c_driver); +} + +static void __exit i2c_adap_nuc900_exit(void) +{ + platform_driver_unregister(&nuc900_i2c_driver); +} +subsys_initcall(i2c_adap_nuc900_init); +module_exit(i2c_adap_nuc900_exit); + +MODULE_DESCRIPTION("NUC900 I2C Bus driver"); +MODULE_AUTHOR("Wan ZongShun, "); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:nuc900-i2c0"); -- cgit v1.2.3 From 35a56c5b821c1a5ab904018f322a8e45afd116f0 Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Wed, 11 Aug 2010 18:20:54 +0200 Subject: i2c-dev: Remove unnecessary kmalloc casts Signed-off-by: Joe Perches Signed-off-by: Jean Delvare --- drivers/i2c/i2c-dev.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index e0694e4d86c7..b3fcb59a5a10 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -219,9 +219,7 @@ static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client, if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS) return -EINVAL; - rdwr_pa = (struct i2c_msg *) - kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), - GFP_KERNEL); + rdwr_pa = kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), GFP_KERNEL); if (!rdwr_pa) return -ENOMEM; -- cgit v1.2.3 From f1c2e33c295de423db5740647bfaa5e2ad139192 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Wed, 11 Aug 2010 18:20:55 +0200 Subject: i2c-dev: Use memdup_user Use memdup_user when user data is immediately copied into the allocated region. Note that in the second case, the ++i is no longer necessary, as the last value is already freed if needed by the call to memdup_user. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // @@ expression from,to,size,flag; position p; identifier l1,l2; @@ - to = \(kmalloc@p\|kzalloc@p\)(size,flag); + to = memdup_user(from,size); if ( - to==NULL + IS_ERR(to) || ...) { <+... when != goto l1; - -ENOMEM + PTR_ERR(to) ...+> } - if (copy_from_user(to, from, size) != 0) { - <+... when != goto l2; - -EFAULT - ...+> - } // Signed-off-by: Julia Lawall Signed-off-by: Jean Delvare --- drivers/i2c/i2c-dev.c | 22 ++++++---------------- 1 file changed, 6 insertions(+), 16 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index b3fcb59a5a10..0b0427f7d348 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -167,13 +167,9 @@ static ssize_t i2cdev_write(struct file *file, const char __user *buf, if (count > 8192) count = 8192; - tmp = kmalloc(count, GFP_KERNEL); - if (tmp == NULL) - return -ENOMEM; - if (copy_from_user(tmp, buf, count)) { - kfree(tmp); - return -EFAULT; - } + tmp = memdup_user(buf, count); + if (IS_ERR(tmp)) + return PTR_ERR(tmp); pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", iminor(file->f_path.dentry->d_inode), count); @@ -245,15 +241,9 @@ static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client, break; } data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; - rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL); - if (rdwr_pa[i].buf == NULL) { - res = -ENOMEM; - break; - } - if (copy_from_user(rdwr_pa[i].buf, data_ptrs[i], - rdwr_pa[i].len)) { - ++i; /* Needs to be kfreed too */ - res = -EFAULT; + rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len); + if (IS_ERR(rdwr_pa[i].buf)) { + res = PTR_ERR(rdwr_pa[i].buf); break; } } -- cgit v1.2.3 From 9a94241afcc9a481691a9c29b7460217925b59b8 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 11 Aug 2010 18:20:56 +0200 Subject: i2c: Add support for custom probe function The probe method used by i2c_new_probed_device() may not be suitable for all cases. Let the caller provide its own, optional probe function. Signed-off-by: Jean Delvare Acked-by: Mauro Carvalho Chehab --- drivers/i2c/i2c-core.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index df937df845eb..cf14ca063181 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1464,14 +1464,18 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) struct i2c_client * i2c_new_probed_device(struct i2c_adapter *adap, struct i2c_board_info *info, - unsigned short const *addr_list) + unsigned short const *addr_list, + int (*probe)(struct i2c_adapter *, unsigned short addr)) { int i; - /* Stop here if the bus doesn't support probing */ - if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { - dev_err(&adap->dev, "Probing not supported\n"); - return NULL; + if (!probe) { + /* Stop here if the bus doesn't support probing */ + if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { + dev_err(&adap->dev, "Probing not supported\n"); + return NULL; + } + probe = i2c_default_probe; } for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { @@ -1490,7 +1494,7 @@ i2c_new_probed_device(struct i2c_adapter *adap, } /* Test address responsiveness */ - if (i2c_default_probe(adap, addr_list[i])) + if (probe(adap, addr_list[i])) break; } -- cgit v1.2.3 From d44f19d586b6113fb5db10e1a36457f0db3b01aa Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 11 Aug 2010 18:20:57 +0200 Subject: V4L/DVB: Use custom I2C probing function mechanism Now that i2c-core offers the possibility to provide custom probing function for I2C devices, let's make use of it. Signed-off-by: Jean Delvare Acked-by: Mauro Carvalho Chehab --- drivers/i2c/i2c-core.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index cf14ca063181..6e1c2f54d9cf 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1461,6 +1461,13 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) return err; } +int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) +{ + return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, + I2C_SMBUS_QUICK, NULL) >= 0; +} +EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); + struct i2c_client * i2c_new_probed_device(struct i2c_adapter *adap, struct i2c_board_info *info, -- cgit v1.2.3 From fe61e07e9ebc890c70d97a1f72ddaad4bee2d848 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 11 Aug 2010 18:20:58 +0200 Subject: i2c: Move adapter locking helpers to i2c-core Uninline i2c adapter locking helper functions, move them to i2c-core, and use them in i2c-core itself. The functions are still exported for external users. This makes future updates to the locking model (which will be needed for multiplexing support) possible and transparent. Signed-off-by: Jean Delvare Cc: Michael Lawnick --- drivers/i2c/i2c-core.c | 39 ++++++++++++++++++++++++++++++++++----- 1 file changed, 34 insertions(+), 5 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 6e1c2f54d9cf..e09e143379b1 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -429,6 +429,35 @@ static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) __i2c_check_addr_busy); } +/** + * i2c_lock_adapter - Get exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment + */ +void i2c_lock_adapter(struct i2c_adapter *adapter) +{ + rt_mutex_lock(&adapter->bus_lock); +} +EXPORT_SYMBOL_GPL(i2c_lock_adapter); + +/** + * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment + */ +static int i2c_trylock_adapter(struct i2c_adapter *adapter) +{ + return rt_mutex_trylock(&adapter->bus_lock); +} + +/** + * i2c_unlock_adapter - Release exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment + */ +void i2c_unlock_adapter(struct i2c_adapter *adapter) +{ + rt_mutex_unlock(&adapter->bus_lock); +} +EXPORT_SYMBOL_GPL(i2c_unlock_adapter); + /** * i2c_new_device - instantiate an i2c device * @adap: the adapter managing the device @@ -1238,12 +1267,12 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) #endif if (in_atomic() || irqs_disabled()) { - ret = rt_mutex_trylock(&adap->bus_lock); + ret = i2c_trylock_adapter(adap); if (!ret) /* I2C activity is ongoing. */ return -EAGAIN; } else { - rt_mutex_lock(&adap->bus_lock); + i2c_lock_adapter(adap); } /* Retry automatically on arbitration loss */ @@ -1255,7 +1284,7 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) if (time_after(jiffies, orig_jiffies + adap->timeout)) break; } - rt_mutex_unlock(&adap->bus_lock); + i2c_unlock_adapter(adap); return ret; } else { @@ -2013,7 +2042,7 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, flags &= I2C_M_TEN | I2C_CLIENT_PEC; if (adapter->algo->smbus_xfer) { - rt_mutex_lock(&adapter->bus_lock); + i2c_lock_adapter(adapter); /* Retry automatically on arbitration loss */ orig_jiffies = jiffies; @@ -2027,7 +2056,7 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, orig_jiffies + adapter->timeout)) break; } - rt_mutex_unlock(&adapter->bus_lock); + i2c_unlock_adapter(adapter); } else res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, command, protocol, data); -- cgit v1.2.3 From d6703281ff20df6c2c0ea7c39a0cc2fa8be3e680 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 11 Aug 2010 18:20:59 +0200 Subject: i2c: Drop dummy variable Now that bus_for_each_drv() is no longer __must_check, we can drop the dummy variable that was used to store the returned value. Signed-off-by: Jean Delvare Cc: Justin P. Mattock --- drivers/i2c/i2c-core.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index e09e143379b1..bb02f8e21a3b 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -789,7 +789,7 @@ static int __process_new_adapter(struct device_driver *d, void *data) static int i2c_register_adapter(struct i2c_adapter *adap) { - int res = 0, dummy; + int res = 0; /* Can't register until after driver model init */ if (unlikely(WARN_ON(!i2c_bus_type.p))) { @@ -830,8 +830,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap) /* Notify drivers */ mutex_lock(&core_lock); - dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, - __process_new_adapter); + bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); mutex_unlock(&core_lock); return 0; -- cgit v1.2.3 From 8031d79baedabd44590d047d97a310eb0e0e4e0c Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 11 Aug 2010 18:21:00 +0200 Subject: i2c: Make i2c_default_probe self-sufficient Make i2c_default_probe self-sufficient, so that callers don't have to do functionality checks themselves. This ensures everything is and will stay consistent. Signed-off-by: Jean Delvare --- drivers/i2c/i2c-core.c | 32 ++++++++++---------------------- 1 file changed, 10 insertions(+), 22 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index bb02f8e21a3b..ba86af63f5cf 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1378,13 +1378,17 @@ static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) I2C_SMBUS_BYTE_DATA, &dummy); else #endif - if ((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50 - || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) - err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, - I2C_SMBUS_BYTE, &dummy); - else + if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) + && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, I2C_SMBUS_QUICK, NULL); + else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) + err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, + I2C_SMBUS_BYTE, &dummy); + else { + dev_warn(&adap->dev, "No suitable probing method supported\n"); + err = -EOPNOTSUPP; + } return err >= 0; } @@ -1465,16 +1469,6 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) if (!(adapter->class & driver->class)) goto exit_free; - /* Stop here if the bus doesn't support probing */ - if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE)) { - if (address_list[0] == I2C_CLIENT_END) - goto exit_free; - - dev_warn(&adapter->dev, "Probing not supported\n"); - err = -EOPNOTSUPP; - goto exit_free; - } - for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { dev_dbg(&adapter->dev, "found normal entry for adapter %d, " "addr 0x%02x\n", adap_id, address_list[i]); @@ -1504,14 +1498,8 @@ i2c_new_probed_device(struct i2c_adapter *adap, { int i; - if (!probe) { - /* Stop here if the bus doesn't support probing */ - if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { - dev_err(&adap->dev, "Probing not supported\n"); - return NULL; - } + if (!probe) probe = i2c_default_probe; - } for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { /* Check address validity */ -- cgit v1.2.3 From dafc50d141c27959dbd3a1cfe9857a86d23402a7 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 11 Aug 2010 18:21:01 +0200 Subject: i2c: Use a separate mutex for userspace client lists Moving userspace-instantiated clients to separate lists wasn't nearly enough to avoid deadlocks in multiplexed bus cases. We also want to have a dedicated mutex to protect each list. Signed-off-by: Jean Delvare Cc: Michael Lawnick --- drivers/i2c/i2c-core.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index ba86af63f5cf..97f96b66653c 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -662,9 +662,9 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, return -EINVAL; /* Keep track of the added device */ - i2c_lock_adapter(adap); + mutex_lock(&adap->userspace_clients_lock); list_add_tail(&client->detected, &adap->userspace_clients); - i2c_unlock_adapter(adap); + mutex_unlock(&adap->userspace_clients_lock); dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", info.type, info.addr); @@ -703,7 +703,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, /* Make sure the device was added through sysfs */ res = -ENOENT; - i2c_lock_adapter(adap); + mutex_lock(&adap->userspace_clients_lock); list_for_each_entry_safe(client, next, &adap->userspace_clients, detected) { if (client->addr == addr) { @@ -716,7 +716,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, break; } } - i2c_unlock_adapter(adap); + mutex_unlock(&adap->userspace_clients_lock); if (res < 0) dev_err(dev, "%s: Can't find device in list\n", @@ -798,6 +798,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap) } rt_mutex_init(&adap->bus_lock); + mutex_init(&adap->userspace_clients_lock); INIT_LIST_HEAD(&adap->userspace_clients); /* Set default timeout to 1 second if not already set */ @@ -1003,7 +1004,7 @@ int i2c_del_adapter(struct i2c_adapter *adap) return res; /* Remove devices instantiated from sysfs */ - i2c_lock_adapter(adap); + mutex_lock(&adap->userspace_clients_lock); list_for_each_entry_safe(client, next, &adap->userspace_clients, detected) { dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, @@ -1011,7 +1012,7 @@ int i2c_del_adapter(struct i2c_adapter *adap) list_del(&client->detected); i2c_unregister_device(client); } - i2c_unlock_adapter(adap); + mutex_unlock(&adap->userspace_clients_lock); /* Detach any active clients. This can't fail, thus we do not checking the returned value. */ -- cgit v1.2.3 From 0826374bff57411d239f2fcb15da3c35af0a93cd Mon Sep 17 00:00:00 2001 From: Michael Lawnick Date: Wed, 11 Aug 2010 18:21:02 +0200 Subject: i2c: Multiplexed I2C bus core support Add multiplexed bus core support. I2C multiplexer and switches like pca954x get instantiated as new adapters per port. Signed-off-by: Michael Lawnick Acked-by: Rodolfo Giometti Signed-off-by: Jean Delvare --- drivers/i2c/Kconfig | 11 ++++ drivers/i2c/Makefile | 1 + drivers/i2c/i2c-core.c | 64 ++++++++++++++++--- drivers/i2c/i2c-dev.c | 40 +++++++++++- drivers/i2c/i2c-mux.c | 165 +++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 273 insertions(+), 8 deletions(-) create mode 100644 drivers/i2c/i2c-mux.c (limited to 'drivers/i2c') diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index d06083fdffbb..efb48ad1ba34 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -47,6 +47,17 @@ config I2C_CHARDEV This support is also available as a module. If so, the module will be called i2c-dev. +config I2C_MUX + tristate "I2C bus multiplexing support" + depends on EXPERIMENTAL + help + Say Y here if you want the I2C core to support the ability to + handle multiplexed I2C bus topologies, by presenting each + multiplexed segment as a I2C adapter. + + This support is also available as a module. If so, the module + will be called i2c-mux. + config I2C_HELPER_AUTO bool "Autoselect pertinent helper modules" default y diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index a7d9b4be9bb3..f363258daa3d 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -6,6 +6,7 @@ obj-$(CONFIG_I2C_BOARDINFO) += i2c-boardinfo.o obj-$(CONFIG_I2C) += i2c-core.o obj-$(CONFIG_I2C_SMBUS) += i2c-smbus.o obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o +obj-$(CONFIG_I2C_MUX) += i2c-mux.o obj-y += algos/ busses/ ifeq ($(CONFIG_I2C_DEBUG_CORE),y) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 97f96b66653c..6649176de940 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -20,7 +20,9 @@ /* With some changes from Kyösti Mälkki . All SMBus-related things are written by Frodo Looijaard SMBus 2.0 support by Mark Studebaker and - Jean Delvare */ + Jean Delvare + Mux support by Rodolfo Giometti and + Michael Lawnick */ #include #include @@ -423,10 +425,48 @@ static int __i2c_check_addr_busy(struct device *dev, void *addrp) return 0; } +/* walk up mux tree */ +static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) +{ + int result; + + result = device_for_each_child(&adapter->dev, &addr, + __i2c_check_addr_busy); + + if (!result && i2c_parent_is_i2c_adapter(adapter)) + result = i2c_check_mux_parents( + to_i2c_adapter(adapter->dev.parent), addr); + + return result; +} + +/* recurse down mux tree */ +static int i2c_check_mux_children(struct device *dev, void *addrp) +{ + int result; + + if (dev->type == &i2c_adapter_type) + result = device_for_each_child(dev, addrp, + i2c_check_mux_children); + else + result = __i2c_check_addr_busy(dev, addrp); + + return result; +} + static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) { - return device_for_each_child(&adapter->dev, &addr, - __i2c_check_addr_busy); + int result = 0; + + if (i2c_parent_is_i2c_adapter(adapter)) + result = i2c_check_mux_parents( + to_i2c_adapter(adapter->dev.parent), addr); + + if (!result) + result = device_for_each_child(&adapter->dev, &addr, + i2c_check_mux_children); + + return result; } /** @@ -435,7 +475,10 @@ static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) */ void i2c_lock_adapter(struct i2c_adapter *adapter) { - rt_mutex_lock(&adapter->bus_lock); + if (i2c_parent_is_i2c_adapter(adapter)) + i2c_lock_adapter(to_i2c_adapter(adapter->dev.parent)); + else + rt_mutex_lock(&adapter->bus_lock); } EXPORT_SYMBOL_GPL(i2c_lock_adapter); @@ -445,7 +488,10 @@ EXPORT_SYMBOL_GPL(i2c_lock_adapter); */ static int i2c_trylock_adapter(struct i2c_adapter *adapter) { - return rt_mutex_trylock(&adapter->bus_lock); + if (i2c_parent_is_i2c_adapter(adapter)) + return i2c_trylock_adapter(to_i2c_adapter(adapter->dev.parent)); + else + return rt_mutex_trylock(&adapter->bus_lock); } /** @@ -454,7 +500,10 @@ static int i2c_trylock_adapter(struct i2c_adapter *adapter) */ void i2c_unlock_adapter(struct i2c_adapter *adapter) { - rt_mutex_unlock(&adapter->bus_lock); + if (i2c_parent_is_i2c_adapter(adapter)) + i2c_unlock_adapter(to_i2c_adapter(adapter->dev.parent)); + else + rt_mutex_unlock(&adapter->bus_lock); } EXPORT_SYMBOL_GPL(i2c_unlock_adapter); @@ -743,10 +792,11 @@ static const struct attribute_group *i2c_adapter_attr_groups[] = { NULL }; -static struct device_type i2c_adapter_type = { +struct device_type i2c_adapter_type = { .groups = i2c_adapter_attr_groups, .release = i2c_adapter_dev_release, }; +EXPORT_SYMBOL_GPL(i2c_adapter_type); #ifdef CONFIG_I2C_COMPAT static struct class_compat *i2c_adapter_compat_class; diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index 0b0427f7d348..5f3a52d517c3 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -189,12 +189,50 @@ static int i2cdev_check(struct device *dev, void *addrp) return dev->driver ? -EBUSY : 0; } +/* walk up mux tree */ +static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr) +{ + int result; + + result = device_for_each_child(&adapter->dev, &addr, i2cdev_check); + + if (!result && i2c_parent_is_i2c_adapter(adapter)) + result = i2cdev_check_mux_parents( + to_i2c_adapter(adapter->dev.parent), addr); + + return result; +} + +/* recurse down mux tree */ +static int i2cdev_check_mux_children(struct device *dev, void *addrp) +{ + int result; + + if (dev->type == &i2c_adapter_type) + result = device_for_each_child(dev, addrp, + i2cdev_check_mux_children); + else + result = i2cdev_check(dev, addrp); + + return result; +} + /* This address checking function differs from the one in i2c-core in that it considers an address with a registered device, but no driver bound to it, as NOT busy. */ static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) { - return device_for_each_child(&adapter->dev, &addr, i2cdev_check); + int result = 0; + + if (i2c_parent_is_i2c_adapter(adapter)) + result = i2cdev_check_mux_parents( + to_i2c_adapter(adapter->dev.parent), addr); + + if (!result) + result = device_for_each_child(&adapter->dev, &addr, + i2cdev_check_mux_children); + + return result; } static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client, diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c new file mode 100644 index 000000000000..d32a4843fc3a --- /dev/null +++ b/drivers/i2c/i2c-mux.c @@ -0,0 +1,165 @@ +/* + * Multiplexed I2C bus driver. + * + * Copyright (c) 2008-2009 Rodolfo Giometti + * Copyright (c) 2008-2009 Eurotech S.p.A. + * Copyright (c) 2009-2010 NSN GmbH & Co KG + * + * Simplifies access to complex multiplexed I2C bus topologies, by presenting + * each multiplexed bus segment as an additional I2C adapter. + * Supports multi-level mux'ing (mux behind a mux). + * + * Based on: + * i2c-virt.c from Kumar Gala + * i2c-virtual.c from Ken Harrenstien, Copyright (c) 2004 Google, Inc. + * i2c-virtual.c from Brian Kuschak + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include +#include +#include +#include +#include + +/* multiplexer per channel data */ +struct i2c_mux_priv { + struct i2c_adapter adap; + struct i2c_algorithm algo; + + struct i2c_adapter *parent; + void *mux_dev; /* the mux chip/device */ + u32 chan_id; /* the channel id */ + + int (*select)(struct i2c_adapter *, void *mux_dev, u32 chan_id); + int (*deselect)(struct i2c_adapter *, void *mux_dev, u32 chan_id); +}; + +static int i2c_mux_master_xfer(struct i2c_adapter *adap, + struct i2c_msg msgs[], int num) +{ + struct i2c_mux_priv *priv = adap->algo_data; + struct i2c_adapter *parent = priv->parent; + int ret; + + /* Switch to the right mux port and perform the transfer. */ + + ret = priv->select(parent, priv->mux_dev, priv->chan_id); + if (ret >= 0) + ret = parent->algo->master_xfer(parent, msgs, num); + if (priv->deselect) + priv->deselect(parent, priv->mux_dev, priv->chan_id); + + return ret; +} + +static int i2c_mux_smbus_xfer(struct i2c_adapter *adap, + u16 addr, unsigned short flags, + char read_write, u8 command, + int size, union i2c_smbus_data *data) +{ + struct i2c_mux_priv *priv = adap->algo_data; + struct i2c_adapter *parent = priv->parent; + int ret; + + /* Select the right mux port and perform the transfer. */ + + ret = priv->select(parent, priv->mux_dev, priv->chan_id); + if (ret >= 0) + ret = parent->algo->smbus_xfer(parent, addr, flags, + read_write, command, size, data); + if (priv->deselect) + priv->deselect(parent, priv->mux_dev, priv->chan_id); + + return ret; +} + +/* Return the parent's functionality */ +static u32 i2c_mux_functionality(struct i2c_adapter *adap) +{ + struct i2c_mux_priv *priv = adap->algo_data; + struct i2c_adapter *parent = priv->parent; + + return parent->algo->functionality(parent); +} + +struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent, + void *mux_dev, u32 force_nr, u32 chan_id, + int (*select) (struct i2c_adapter *, + void *, u32), + int (*deselect) (struct i2c_adapter *, + void *, u32)) +{ + struct i2c_mux_priv *priv; + int ret; + + priv = kzalloc(sizeof(struct i2c_mux_priv), GFP_KERNEL); + if (!priv) + return NULL; + + /* Set up private adapter data */ + priv->parent = parent; + priv->mux_dev = mux_dev; + priv->chan_id = chan_id; + priv->select = select; + priv->deselect = deselect; + + /* Need to do algo dynamically because we don't know ahead + * of time what sort of physical adapter we'll be dealing with. + */ + if (parent->algo->master_xfer) + priv->algo.master_xfer = i2c_mux_master_xfer; + if (parent->algo->smbus_xfer) + priv->algo.smbus_xfer = i2c_mux_smbus_xfer; + priv->algo.functionality = i2c_mux_functionality; + + /* Now fill out new adapter structure */ + snprintf(priv->adap.name, sizeof(priv->adap.name), + "i2c-%d-mux (chan_id %d)", i2c_adapter_id(parent), chan_id); + priv->adap.owner = THIS_MODULE; + priv->adap.id = parent->id; + priv->adap.algo = &priv->algo; + priv->adap.algo_data = priv; + priv->adap.dev.parent = &parent->dev; + + if (force_nr) { + priv->adap.nr = force_nr; + ret = i2c_add_numbered_adapter(&priv->adap); + } else { + ret = i2c_add_adapter(&priv->adap); + } + if (ret < 0) { + dev_err(&parent->dev, + "failed to add mux-adapter (error=%d)\n", + ret); + kfree(priv); + return NULL; + } + + dev_info(&parent->dev, "Added multiplexed i2c bus %d\n", + i2c_adapter_id(&priv->adap)); + + return &priv->adap; +} +EXPORT_SYMBOL_GPL(i2c_add_mux_adapter); + +int i2c_del_mux_adapter(struct i2c_adapter *adap) +{ + struct i2c_mux_priv *priv = adap->algo_data; + int ret; + + ret = i2c_del_adapter(adap); + if (ret < 0) + return ret; + kfree(priv); + + return 0; +} +EXPORT_SYMBOL_GPL(i2c_del_mux_adapter); + +MODULE_AUTHOR("Rodolfo Giometti "); +MODULE_DESCRIPTION("I2C driver for multiplexed I2C busses"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3 From 7f528135da9704d67db1f727162024b078e1cd8f Mon Sep 17 00:00:00 2001 From: Michael Lawnick Date: Wed, 11 Aug 2010 18:21:03 +0200 Subject: i2c: I2C bus multiplexer driver pca954x I2C driver for PCA954x I2C multiplexer series. Signed-off-by: Michael Lawnick Acked-by: Rodolfo Giometti Signed-off-by: Jean Delvare --- drivers/i2c/Kconfig | 2 + drivers/i2c/Makefile | 2 +- drivers/i2c/muxes/Kconfig | 18 +++ drivers/i2c/muxes/Makefile | 8 ++ drivers/i2c/muxes/pca954x.c | 301 ++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 330 insertions(+), 1 deletion(-) create mode 100644 drivers/i2c/muxes/Kconfig create mode 100644 drivers/i2c/muxes/Makefile create mode 100644 drivers/i2c/muxes/pca954x.c (limited to 'drivers/i2c') diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index efb48ad1ba34..30f06e956bfb 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -58,6 +58,8 @@ config I2C_MUX This support is also available as a module. If so, the module will be called i2c-mux. +source drivers/i2c/muxes/Kconfig + config I2C_HELPER_AUTO bool "Autoselect pertinent helper modules" default y diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index f363258daa3d..c00fd66388f5 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -7,7 +7,7 @@ obj-$(CONFIG_I2C) += i2c-core.o obj-$(CONFIG_I2C_SMBUS) += i2c-smbus.o obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o obj-$(CONFIG_I2C_MUX) += i2c-mux.o -obj-y += algos/ busses/ +obj-y += algos/ busses/ muxes/ ifeq ($(CONFIG_I2C_DEBUG_CORE),y) EXTRA_CFLAGS += -DDEBUG diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig new file mode 100644 index 000000000000..4c9a99c4fcb0 --- /dev/null +++ b/drivers/i2c/muxes/Kconfig @@ -0,0 +1,18 @@ +# +# Multiplexer I2C chip drivers configuration +# + +menu "Multiplexer I2C Chip support" + depends on I2C_MUX + +config I2C_MUX_PCA954x + tristate "Philips PCA954x I2C Mux/switches" + depends on EXPERIMENTAL + help + If you say yes here you get support for the Philips PCA954x + I2C mux/switch devices. + + This driver can also be built as a module. If so, the module + will be called pca954x. + +endmenu diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile new file mode 100644 index 000000000000..bd83b5274815 --- /dev/null +++ b/drivers/i2c/muxes/Makefile @@ -0,0 +1,8 @@ +# +# Makefile for multiplexer I2C chip drivers. + +obj-$(CONFIG_I2C_MUX_PCA954x) += pca954x.o + +ifeq ($(CONFIG_I2C_DEBUG_BUS),y) +EXTRA_CFLAGS += -DDEBUG +endif diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c new file mode 100644 index 000000000000..6f9accf3189d --- /dev/null +++ b/drivers/i2c/muxes/pca954x.c @@ -0,0 +1,301 @@ +/* + * I2C multiplexer + * + * Copyright (c) 2008-2009 Rodolfo Giometti + * Copyright (c) 2008-2009 Eurotech S.p.A. + * + * This module supports the PCA954x series of I2C multiplexer/switch chips + * made by Philips Semiconductors. + * This includes the: + * PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547 + * and PCA9548. + * + * These chips are all controlled via the I2C bus itself, and all have a + * single 8-bit register. The upstream "parent" bus fans out to two, + * four, or eight downstream busses or channels; which of these + * are selected is determined by the chip type and register contents. A + * mux can select only one sub-bus at a time; a switch can select any + * combination simultaneously. + * + * Based on: + * pca954x.c from Kumar Gala + * Copyright (C) 2006 + * + * Based on: + * pca954x.c from Ken Harrenstien + * Copyright (C) 2004 Google, Inc. (Ken Harrenstien) + * + * Based on: + * i2c-virtual_cb.c from Brian Kuschak + * and + * pca9540.c from Jean Delvare . + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include +#include +#include +#include +#include +#include + +#include + +#define PCA954X_MAX_NCHANS 8 + +enum pca_type { + pca_9540, + pca_9542, + pca_9543, + pca_9544, + pca_9545, + pca_9546, + pca_9547, + pca_9548, +}; + +struct pca954x { + enum pca_type type; + struct i2c_adapter *virt_adaps[PCA954X_MAX_NCHANS]; + + u8 last_chan; /* last register value */ +}; + +struct chip_desc { + u8 nchans; + u8 enable; /* used for muxes only */ + enum muxtype { + pca954x_ismux = 0, + pca954x_isswi + } muxtype; +}; + +/* Provide specs for the PCA954x types we know about */ +static const struct chip_desc chips[] = { + [pca_9540] = { + .nchans = 2, + .enable = 0x4, + .muxtype = pca954x_ismux, + }, + [pca_9543] = { + .nchans = 2, + .muxtype = pca954x_isswi, + }, + [pca_9544] = { + .nchans = 4, + .enable = 0x4, + .muxtype = pca954x_ismux, + }, + [pca_9545] = { + .nchans = 4, + .muxtype = pca954x_isswi, + }, + [pca_9547] = { + .nchans = 8, + .enable = 0x8, + .muxtype = pca954x_ismux, + }, + [pca_9548] = { + .nchans = 8, + .muxtype = pca954x_isswi, + }, +}; + +static const struct i2c_device_id pca954x_id[] = { + { "pca9540", pca_9540 }, + { "pca9542", pca_9540 }, + { "pca9543", pca_9543 }, + { "pca9544", pca_9544 }, + { "pca9545", pca_9545 }, + { "pca9546", pca_9545 }, + { "pca9547", pca_9547 }, + { "pca9548", pca_9548 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, pca954x_id); + +/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer() + for this as they will try to lock adapter a second time */ +static int pca954x_reg_write(struct i2c_adapter *adap, + struct i2c_client *client, u8 val) +{ + int ret = -ENODEV; + + if (adap->algo->master_xfer) { + struct i2c_msg msg; + char buf[1]; + + msg.addr = client->addr; + msg.flags = 0; + msg.len = 1; + buf[0] = val; + msg.buf = buf; + ret = adap->algo->master_xfer(adap, &msg, 1); + } else { + union i2c_smbus_data data; + ret = adap->algo->smbus_xfer(adap, client->addr, + client->flags, + I2C_SMBUS_WRITE, + val, I2C_SMBUS_BYTE, &data); + } + + return ret; +} + +static int pca954x_select_chan(struct i2c_adapter *adap, + void *client, u32 chan) +{ + struct pca954x *data = i2c_get_clientdata(client); + const struct chip_desc *chip = &chips[data->type]; + u8 regval; + int ret = 0; + + /* we make switches look like muxes, not sure how to be smarter */ + if (chip->muxtype == pca954x_ismux) + regval = chan | chip->enable; + else + regval = 1 << chan; + + /* Only select the channel if its different from the last channel */ + if (data->last_chan != regval) { + ret = pca954x_reg_write(adap, client, regval); + data->last_chan = regval; + } + + return ret; +} + +static int pca954x_deselect_mux(struct i2c_adapter *adap, + void *client, u32 chan) +{ + struct pca954x *data = i2c_get_clientdata(client); + + /* Deselect active channel */ + data->last_chan = 0; + return pca954x_reg_write(adap, client, data->last_chan); +} + +/* + * I2C init/probing/exit functions + */ +static int __devinit pca954x_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent); + struct pca954x_platform_data *pdata = client->dev.platform_data; + int num, force; + struct pca954x *data; + int ret = -ENODEV; + + if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE)) + goto err; + + data = kzalloc(sizeof(struct pca954x), GFP_KERNEL); + if (!data) { + ret = -ENOMEM; + goto err; + } + + i2c_set_clientdata(client, data); + + /* Read the mux register at addr to verify + * that the mux is in fact present. + */ + if (i2c_smbus_read_byte(client) < 0) { + dev_warn(&client->dev, "probe failed\n"); + goto exit_free; + } + + data->type = id->driver_data; + data->last_chan = 0; /* force the first selection */ + + /* Now create an adapter for each channel */ + for (num = 0; num < chips[data->type].nchans; num++) { + force = 0; /* dynamic adap number */ + if (pdata) { + if (num < pdata->num_modes) + /* force static number */ + force = pdata->modes[num].adap_id; + else + /* discard unconfigured channels */ + break; + } + + data->virt_adaps[num] = + i2c_add_mux_adapter(adap, client, + force, num, pca954x_select_chan, + (pdata && pdata->modes[num].deselect_on_exit) + ? pca954x_deselect_mux : NULL); + + if (data->virt_adaps[num] == NULL) { + ret = -ENODEV; + dev_err(&client->dev, + "failed to register multiplexed adapter" + " %d as bus %d\n", num, force); + goto virt_reg_failed; + } + } + + dev_info(&client->dev, + "registered %d multiplexed busses for I2C %s %s\n", + num, chips[data->type].muxtype == pca954x_ismux + ? "mux" : "switch", client->name); + + return 0; + +virt_reg_failed: + for (num--; num >= 0; num--) + i2c_del_mux_adapter(data->virt_adaps[num]); +exit_free: + kfree(data); +err: + return ret; +} + +static int __devexit pca954x_remove(struct i2c_client *client) +{ + struct pca954x *data = i2c_get_clientdata(client); + const struct chip_desc *chip = &chips[data->type]; + int i, err; + + for (i = 0; i < chip->nchans; ++i) + if (data->virt_adaps[i]) { + err = i2c_del_mux_adapter(data->virt_adaps[i]); + if (err) + return err; + data->virt_adaps[i] = NULL; + } + + kfree(data); + return 0; +} + +static struct i2c_driver pca954x_driver = { + .driver = { + .name = "pca954x", + .owner = THIS_MODULE, + }, + .probe = pca954x_probe, + .remove = __devexit_p(pca954x_remove), + .id_table = pca954x_id, +}; + +static int __init pca954x_init(void) +{ + return i2c_add_driver(&pca954x_driver); +} + +static void __exit pca954x_exit(void) +{ + i2c_del_driver(&pca954x_driver); +} + +module_init(pca954x_init); +module_exit(pca954x_exit); + +MODULE_AUTHOR("Rodolfo Giometti "); +MODULE_DESCRIPTION("PCA954x I2C mux/switch driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3