From: Ganesan Ramalingam <ganesanr@xxxxxxxxxxxx>
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@xxxxxxxxxxxx>
Signed-off-by: Jayachandran C <jayachandranc@xxxxxxxxxxxxxxxxx>
---
.../devicetree/bindings/i2c/i2c-ocores.txt | 2 ++
drivers/i2c/busses/i2c-ocores.c | 21 ++++++++++++++++++--
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 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 fb8db30..7e710bd 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;
int reg_shift;
+ int 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)
@@ -245,6 +256,8 @@ static int ocores_i2c_of_probe(struct platform_device *pdev,
}
i2c->clock_khz = val / 1000;
+ if (!of_property_read_u32(pdev->dev.of_node, "reg-io-width", &val))
+ i2c->reg_io_width = val;
return 0;
}
#else
@@ -287,6 +300,7 @@ 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);
@@ -294,6 +308,9 @@ 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 75d7767..5fef682 100644
--- a/include/linux/i2c-ocores.h
+++ b/include/linux/i2c-ocores.h
@@ -13,6 +13,7 @@
struct ocores_i2c_platform_data {
int reg_shift; /* register offset shift value */
+ int 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 */
--
1.7.9.5
--
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