[U-Boot] [PATCH] video: Remove dependecy of I2C_EDID

[Simon Glass]

Hi,

On 9 April 2017 at 15:30, Jernej Škrabec <jernej.skrabec at siol.net> wrote:
> Hi,
>
> Dne nedelja, 09. april 2017 ob 21:28:47 CEST je Simon Glass napisal(a):
>> Hi,
>>
>> On 28 March 2017 at 16:39, Jernej Skrabec <jernej.skrabec at siol.net> wrote:
>> > I2C_EDID currently selects DM_I2C. However, it is not needed. I2C_EDID
>> > is used for building edid.c, which doesn't even use I2C bus, and by I2C
>> > command, which knows how to use DM and old style I2C interface, so it is
>> > not directly affected by this removal.
>> >
>> > Furthermore, this selection can generate warning if DM display driver
>> > is used on platform which doesn't implement DM I2C driver (for example,
>> > sunxi platform with upcoming DM video & display driver).
>> >
>> > Patch was tested with rockchip and sunxi boards and successfully
>> > compiled exynos and tegra targets. They are the only consumers of
>> > CONFIG_DISPLAY option, which is the only one which selects I2C_EDID.
>> >
>> > Signed-off-by: Jernej Skrabec <jernej.skrabec at siol.net>
>> > ---
>> >
>> >  cmd/i2c.c             | 10 ++++++----
>> >  drivers/video/Kconfig |  1 -
>> >  2 files changed, 6 insertions(+), 5 deletions(-)
>> >
>> > diff --git a/cmd/i2c.c b/cmd/i2c.c
>> > index 473153fbd4..7b6306e525 100644
>> > --- a/cmd/i2c.c
>> > +++ b/cmd/i2c.c
>> > @@ -1630,7 +1630,8 @@ static int do_sdram (cmd_tbl_t * cmdtp, int flag,
>> > int argc, char * const argv[])>
>> >   * Syntax:
>> >   *     i2c edid {i2c_chip}
>> >   */
>> >
>> > -#if defined(CONFIG_I2C_EDID)
>> > +#if defined(CONFIG_I2C_EDID) && \
>> > +       (defined(CONFIG_SYS_I2C) || defined(CONFIG_DM_I2C))
>>
>> The correct solution here I think is to convert sunxi to DM_I2C. We
>> should not be adding new features to the old code.
>
> With the "old code" you referring to i2c command? Actually, I'm not sure if
> "i2c edid" command can be useful on most platforms. I know that rk3288 has
> multiplexed I2C controller pins with HDMI DDC pins, where this make sense. But
> for example on sunxi, in order to be useful, it would mean that dw_hdmi driver
> has to register DDC as I2C driver.
>
> I'm also not sure why "i2c edid" code knows how to use old and DM I2C
> interface when it is surrounded by a symbol, which always selects DM_I2C.
> Well, in sunxi case, that actually prevents build failure, but still produces
> unwanted warning.
>
> Otherwise I agree that converting sunxi to DM_I2C should be done and patch for
> that already exists, but it was not merged yet:
> https://patchwork.ozlabs.org/patch/734375/

Sounds good. Let's get that merged and then we don't need to worry
about the legacy I2C.

Regards
Simon