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 <[email protected]>
Signed-off-by: Jayachandran C <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>
This commit is contained in:
Ganesan Ramalingam 2012-07-13 19:14:25 +05:30 • committed by Wolfram Sang
commit 7326e38ffe
3 changed files with 22 additions and 2 deletions

View file

@ -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);