[linux-sunxi] [PATCH] pinctrl: sun4i: add spdif to pin description.

[Hans de Goede]

Hi,

On 12-08-15 07:31, Code Kipper wrote:
> On 11 August 2015 at 18:48, Chen-Yu Tsai <wens at csie.org> wrote:
>
>> On Wed, Aug 12, 2015 at 12:19 AM,  <codekipper at gmail.com> wrote:
>>> From: Marcus Cooper <codekipper at gmail.com>
>>>
>>> Signed-off-by: Marcus Cooper <codekipper at gmail.com>
>>> ---
>>>   drivers/pinctrl/sunxi/pinctrl-sun4i-a10.c | 9 ++++++---
>>>   1 file changed, 6 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/pinctrl/sunxi/pinctrl-sun4i-a10.c
>> b/drivers/pinctrl/sunxi/pinctrl-sun4i-a10.c
>>> index 7376a97..daf7dec 100644
>>> --- a/drivers/pinctrl/sunxi/pinctrl-sun4i-a10.c
>>> +++ b/drivers/pinctrl/sunxi/pinctrl-sun4i-a10.c
>>> @@ -135,7 +135,8 @@ static const struct sunxi_desc_pin sun4i_a10_pins[]
>> = {
>>>          SUNXI_PIN(SUNXI_PINCTRL_PIN(B, 3),
>>>                    SUNXI_FUNCTION(0x0, "gpio_in"),
>>>                    SUNXI_FUNCTION(0x1, "gpio_out"),
>>> -                 SUNXI_FUNCTION(0x2, "ir0")),          /* TX */
>>> +                 SUNXI_FUNCTION(0x2, "ir0"),           /* TX */
>>> +                 SUNXI_FUNCTION(0x4, "spdif")),        /* MCLK */
>>>          SUNXI_PIN(SUNXI_PINCTRL_PIN(B, 4),
>>>                    SUNXI_FUNCTION(0x0, "gpio_in"),
>>>                    SUNXI_FUNCTION(0x1, "gpio_out"),
>>> @@ -176,11 +177,13 @@ static const struct sunxi_desc_pin
>> sun4i_a10_pins[] = {
>>>                    SUNXI_FUNCTION(0x0, "gpio_in"),
>>>                    SUNXI_FUNCTION(0x1, "gpio_out"),
>>>                    SUNXI_FUNCTION(0x2, "i2s"),           /* DI */
>>> -                 SUNXI_FUNCTION(0x3, "ac97")),         /* DI */
>>> +                 SUNXI_FUNCTION(0x3, "ac97"),          /* DI */
>>> +                 SUNXI_FUNCTION(0x4, "spdif")),        /* DI */
>>>          SUNXI_PIN(SUNXI_PINCTRL_PIN(B, 13),
>>>                    SUNXI_FUNCTION(0x0, "gpio_in"),
>>>                    SUNXI_FUNCTION(0x1, "gpio_out"),
>>> -                 SUNXI_FUNCTION(0x2, "spi2")),         /* CS1 */
>>> +                 SUNXI_FUNCTION(0x2, "spi2"),          /* CS1 */
>>> +                 SUNXI_FUNCTION(0x4, "spdif")),        /* DO */
>>
>> The datasheet and manual list them as NC or Reserved. Maybe mention how
>> you knew
>> they were available?
>>
> Not sure if this deserves to be in the commit message but I can definitely
> put together a covering letter with links etc.

I dear to say it belongs right there in the source code, use a multi-line
comment above the SUNXI_FUNCTION(0x4, "spdif")) to explain where the mux
info comes from. someday sooner or later someone is going to compare the
kernel mux table to the datasheet and think "huh, that is not right",
that person will be saved an immense amount of time by simply having a
comment there.

And do NOT say that this will not happen, because I've already done
such a comparison once in the past.

Regards,

Hans