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| author | Ganesan Ramalingam <ganesanr@broadcom.com> | 2012-07-13 19:14:25 +0530 |
|---|---|---|
| committer | Wolfram Sang <w.sang@pengutronix.de> | 2012-07-14 13:30:25 +0200 |
| commit | 7326e38ffe894d0cd2904704b7d8c53d4a55d752 (patch) | |
| tree | 7261b5bad76ce15dbad07f78a5b5e4b210f6d634 | |
| parent | d739a464f3b83cc879a2ba6aec33634c44068531 (diff) | |
| download | linux-7326e38ffe894d0cd2904704b7d8c53d4a55d752.tar.gz linux-7326e38ffe894d0cd2904704b7d8c53d4a55d752.tar.bz2 linux-7326e38ffe894d0cd2904704b7d8c53d4a55d752.zip | |
i2c: i2c-ocores: support for 16bit and 32bit IO
Some architectures supports only 16-bit or 32-bit read/write access to
their IO space. Add a 'reg-io-width' platform and OF parameter which
specifies the IO width to support these platforms.
reg-io-width can be specified as 1, 2 or 4, and has a default value
of 1 if it is unspecified.
Signed-off-by: Ganesan Ramalingam <ganesanr@broadcom.com>
Signed-off-by: Jayachandran C <jayachandranc@netlogicmicro.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-ocores.txt | 2 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-ocores.c | 21 | ||||
| -rw-r--r-- | include/linux/i2c-ocores.h | 1 |
3 files changed, 22 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt index 1c9334bfc39c..c15781f4dc8c 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt @@ -10,6 +10,7 @@ Required properties: Optional properties: - reg-shift : device register offsets are shifted by this value +- reg-io-width : io register width in bytes (1, 2 or 4) - regstep : deprecated, use reg-shift above Example: @@ -23,6 +24,7 @@ Example: clock-frequency = <20000000>; reg-shift = <0>; /* 8 bit registers */ + reg-io-width = <1>; /* 8 bit read/write */ dummy@60 { compatible = "dummy"; diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c index 9e0709d5fb36..bffd5501ac2d 100644 --- a/drivers/i2c/busses/i2c-ocores.c +++ b/drivers/i2c/busses/i2c-ocores.c @@ -30,6 +30,7 @@ struct ocores_i2c { void __iomem *base; u32 reg_shift; + u32 reg_io_width; wait_queue_head_t wait; struct i2c_adapter adap; struct i2c_msg *msg; @@ -72,12 +73,22 @@ struct ocores_i2c { static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value) { - iowrite8(value, i2c->base + (reg << i2c->reg_shift)); + if (i2c->reg_io_width == 4) + iowrite32(value, i2c->base + (reg << i2c->reg_shift)); + else if (i2c->reg_io_width == 2) + iowrite16(value, i2c->base + (reg << i2c->reg_shift)); + else + iowrite8(value, i2c->base + (reg << i2c->reg_shift)); } static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg) { - return ioread8(i2c->base + (reg << i2c->reg_shift)); + if (i2c->reg_io_width == 4) + return ioread32(i2c->base + (reg << i2c->reg_shift)); + else if (i2c->reg_io_width == 2) + return ioread16(i2c->base + (reg << i2c->reg_shift)); + else + return ioread8(i2c->base + (reg << i2c->reg_shift)); } static void ocores_process(struct ocores_i2c *i2c) @@ -244,6 +255,8 @@ static int ocores_i2c_of_probe(struct platform_device *pdev, } i2c->clock_khz = val / 1000; + of_property_read_u32(pdev->dev.of_node, "reg-io-width", + &i2c->reg_io_width); return 0; } #else @@ -286,6 +299,7 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev) pdata = pdev->dev.platform_data; if (pdata) { i2c->reg_shift = pdata->reg_shift; + i2c->reg_io_width = pdata->reg_io_width; i2c->clock_khz = pdata->clock_khz; } else { ret = ocores_i2c_of_probe(pdev, i2c); @@ -293,6 +307,9 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev) return ret; } + if (i2c->reg_io_width == 0) + i2c->reg_io_width = 1; /* Set to default value */ + ocores_init(i2c); init_waitqueue_head(&i2c->wait); diff --git a/include/linux/i2c-ocores.h b/include/linux/i2c-ocores.h index 5d95df2436f4..1c06b5c7c308 100644 --- a/include/linux/i2c-ocores.h +++ b/include/linux/i2c-ocores.h @@ -13,6 +13,7 @@ struct ocores_i2c_platform_data { u32 reg_shift; /* register offset shift value */ + u32 reg_io_width; /* register io read/write width */ u32 clock_khz; /* input clock in kHz */ u8 num_devices; /* number of devices in the devices list */ struct i2c_board_info const *devices; /* devices connected to the bus */ |