On Tue, Jul 10, 2012 at 11:40:58AM +0530, Jayachandran C wrote:
> 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 9617ec1..034d1d5 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;
u32 again.
> 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));
Hmm, this could be a helper function, probably. But nothing you'd need
to do right now...
Thanks,
Wolfram
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