summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorGanesan Ramalingam <ganesanr@broadcom.com>2012-07-13 19:14:25 +0530
committerWolfram Sang <w.sang@pengutronix.de>2012-07-14 13:30:25 +0200
commit7326e38ffe894d0cd2904704b7d8c53d4a55d752 (patch)
tree7261b5bad76ce15dbad07f78a5b5e4b210f6d634
parentd739a464f3b83cc879a2ba6aec33634c44068531 (diff)
downloadop-kernel-dev-7326e38ffe894d0cd2904704b7d8c53d4a55d752.zip
op-kernel-dev-7326e38ffe894d0cd2904704b7d8c53d4a55d752.tar.gz
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.txt2
-rw-r--r--drivers/i2c/busses/i2c-ocores.c21
-rw-r--r--include/linux/i2c-ocores.h1
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 1c9334b..c15781f 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 9e0709d..bffd550 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 5d95df2..1c06b5c 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 */
OpenPOWER on IntegriCloud