diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-omap.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-omap.c | 82 |
1 files changed, 60 insertions, 22 deletions
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 5ca0e0010a0e..b0aa0f8b564b 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -83,6 +83,7 @@ /* I2C Configuration Register (OMAP_I2C_CON): */ #define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */ #define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */ +#define OMAP_I2C_CON_OPMODE (1 << 12) /* High Speed support */ #define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */ #define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */ #define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */ @@ -91,6 +92,10 @@ #define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */ #define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */ +/* I2C SCL time value when Master */ +#define OMAP_I2C_SCLL_HSSCLL 8 +#define OMAP_I2C_SCLH_HSSCLH 8 + /* I2C System Test Register (OMAP_I2C_SYSTEST): */ #ifdef DEBUG #define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */ @@ -109,12 +114,6 @@ /* I2C System Configuration Register (OMAP_I2C_SYSC): */ #define OMAP_I2C_SYSC_SRST (1 << 1) /* Soft Reset */ -/* REVISIT: Use platform_data instead of module parameters */ -/* Fast Mode = 400 kHz, Standard = 100 kHz */ -static int clock = 100; /* Default: 100 kHz */ -module_param(clock, int, 0); -MODULE_PARM_DESC(clock, "Set I2C clock in kHz: 400=fast mode (default == 100)"); - struct omap_i2c_dev { struct device *dev; void __iomem *base; /* virtual */ @@ -123,6 +122,7 @@ struct omap_i2c_dev { struct clk *fclk; /* Functional clock */ struct completion cmd_complete; struct resource *ioarea; + u32 speed; /* Speed of bus in Khz */ u16 cmd_err; u8 *buf; size_t buf_len; @@ -208,9 +208,11 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev) static int omap_i2c_init(struct omap_i2c_dev *dev) { - u16 psc = 0; + u16 psc = 0, scll = 0, sclh = 0; + u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0; unsigned long fclk_rate = 12000000; unsigned long timeout; + unsigned long internal_clk = 0; if (!dev->rev1) { omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, OMAP_I2C_SYSC_SRST); @@ -253,18 +255,47 @@ static int omap_i2c_init(struct omap_i2c_dev *dev) psc = fclk_rate / 12000000; } + if (cpu_is_omap2430()) { + + /* HSI2C controller internal clk rate should be 19.2 Mhz */ + internal_clk = 19200; + fclk_rate = clk_get_rate(dev->fclk) / 1000; + + /* Compute prescaler divisor */ + psc = fclk_rate / internal_clk; + psc = psc - 1; + + /* If configured for High Speed */ + if (dev->speed > 400) { + /* For first phase of HS mode */ + fsscll = internal_clk / (400 * 2) - 6; + fssclh = internal_clk / (400 * 2) - 6; + + /* For second phase of HS mode */ + hsscll = fclk_rate / (dev->speed * 2) - 6; + hssclh = fclk_rate / (dev->speed * 2) - 6; + } else { + /* To handle F/S modes */ + fsscll = internal_clk / (dev->speed * 2) - 6; + fssclh = internal_clk / (dev->speed * 2) - 6; + } + scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll; + sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh; + } else { + /* Program desired operating rate */ + fclk_rate /= (psc + 1) * 1000; + if (psc > 2) + psc = 2; + scll = fclk_rate / (dev->speed * 2) - 7 + psc; + sclh = fclk_rate / (dev->speed * 2) - 7 + psc; + } + /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */ omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc); - /* Program desired operating rate */ - fclk_rate /= (psc + 1) * 1000; - if (psc > 2) - psc = 2; - - omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, - fclk_rate / (clock * 2) - 7 + psc); - omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, - fclk_rate / (clock * 2) - 7 + psc); + /* SCL low and high time values */ + omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll); + omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh); /* Take the I2C module out of reset: */ omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); @@ -324,6 +355,11 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, dev->cmd_err = 0; w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT; + + /* High speed configuration */ + if (dev->speed > 400) + w |= OMAP_I2C_CON_OPMODE; + if (msg->flags & I2C_M_TEN) w |= OMAP_I2C_CON_XA; if (!(msg->flags & I2C_M_RD)) @@ -564,6 +600,7 @@ omap_i2c_probe(struct platform_device *pdev) struct i2c_adapter *adap; struct resource *mem, *irq, *ioarea; int r; + u32 *speed = NULL; /* NOTE: driver uses the static register mapping */ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -584,17 +621,18 @@ omap_i2c_probe(struct platform_device *pdev) return -EBUSY; } - if (clock > 200) - clock = 400; /* Fast mode */ - else - clock = 100; /* Standard mode */ - dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL); if (!dev) { r = -ENOMEM; goto err_release_region; } + if (pdev->dev.platform_data != NULL) + speed = (u32 *) pdev->dev.platform_data; + else + *speed = 100; /* Defualt speed */ + + dev->speed = *speed; dev->dev = &pdev->dev; dev->irq = irq->start; dev->base = ioremap(mem->start, mem->end - mem->start + 1); @@ -625,7 +663,7 @@ omap_i2c_probe(struct platform_device *pdev) } r = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff; dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n", - pdev->id, r >> 4, r & 0xf, clock); + pdev->id, r >> 4, r & 0xf, dev->speed); adap = &dev->adapter; i2c_set_adapdata(adap, dev); |