Hi Jean,
Can you please review and if you don't have any objectsion, ack this patch
for merging through drm-intel-next? Imo that's the easiest way to merge
this series.
Thanks, Daniel
On Tue, Feb 14, 2012 at 10:37:21PM +0100, Daniel Vetter wrote:
> i915 has a hw i2c controller (gmbus) but for a bunch of stupid reasons
> we need to be able to fall back to the bit-banging algo on gpio pins.
>
> The current code sets up a 2nd i2c controller for the same i2c bus using
> the bit-banging algo. This has a bunch of issues, the major one being
> that userspace can directly access this fallback i2c adaptor behind
> the drivers back.
>
> But we need to frob a few registers before and after using fallback
> gpio bit-banging, so this horribly fails.
>
> The new plan is to only set up one i2c adaptor and transparently fall
> back to bit-banging by directly calling the xfer function of the bit-
> banging algo in the i2c core.
>
> To make that possible, export the 2 i2c algo functions.
>
> Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
> drivers/i2c/algos/i2c-algo-bit.c | 12 +++++++-----
> include/linux/i2c-algo-bit.h | 4 ++++
> 2 files changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
> index 525c734..ec1651a 100644
> --- a/drivers/i2c/algos/i2c-algo-bit.c
> +++ b/drivers/i2c/algos/i2c-algo-bit.c
> @@ -531,8 +531,8 @@ static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
> return 0;
> }
>
> -static int bit_xfer(struct i2c_adapter *i2c_adap,
> - struct i2c_msg msgs[], int num)
> +int i2c_bit_xfer(struct i2c_adapter *i2c_adap,
> + struct i2c_msg msgs[], int num)
> {
> struct i2c_msg *pmsg;
> struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
> @@ -598,21 +598,23 @@ bailout:
> adap->post_xfer(i2c_adap);
> return ret;
> }
> +EXPORT_SYMBOL(i2c_bit_xfer);
>
> -static u32 bit_func(struct i2c_adapter *adap)
> +u32 i2c_bit_func(struct i2c_adapter *adap)
> {
> return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
> I2C_FUNC_SMBUS_READ_BLOCK_DATA |
> I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
> I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;
> }
> +EXPORT_SYMBOL(i2c_bit_func);
>
>
> /* -----exported algorithm data: ------------------------------------- */
>
> static const struct i2c_algorithm i2c_bit_algo = {
> - .master_xfer = bit_xfer,
> - .functionality = bit_func,
> + .master_xfer = i2c_bit_xfer,
> + .functionality = i2c_bit_func,
> };
>
> /*
> diff --git a/include/linux/i2c-algo-bit.h b/include/linux/i2c-algo-bit.h
> index 4f98148..cdd6336 100644
> --- a/include/linux/i2c-algo-bit.h
> +++ b/include/linux/i2c-algo-bit.h
> @@ -47,6 +47,10 @@ struct i2c_algo_bit_data {
> int timeout; /* in jiffies */
> };
>
> +int i2c_bit_xfer(struct i2c_adapter *i2c_adap,
> + struct i2c_msg msgs[], int num);
> +u32 i2c_bit_func(struct i2c_adapter *adap);
> +
> int i2c_bit_add_bus(struct i2c_adapter *);
> int i2c_bit_add_numbered_bus(struct i2c_adapter *);
>
> --
> 1.7.7.5
>
--
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48
