Hi Geert,
On 06/12/2017 04:18 PM, Geert Uytterhoeven wrote:
> On Mon, Jun 12, 2017 at 9:15 AM, Shawn Lin <shawn.lin at rock-chips.com> wrote:
>> On 2017/6/12 14:14, Jeffy Chen wrote:
>>>
>>> Support using "cs-gpios" property to specify cs gpios.
>>>
>>> Signed-off-by: Jeffy Chen <jeffy.chen at rock-chips.com>
>
>>> index 83da493..02171b2 100644
>>> --- a/Documentation/devicetree/bindings/spi/spi-rockchip.txt
>>> +++ b/Documentation/devicetree/bindings/spi/spi-rockchip.txt
>>> @@ -17,6 +17,7 @@ Required Properties:
>>> region.
>>> - interrupts: The interrupt number to the cpu. The interrupt specifier
>>> format
>>> depends on the interrupt controller.
>>> +- cs-gpios : Specifies the gpio pins to be used for chipselects.
>>
>> It's not a required property, otherwise how other boards work as your
>> patch 2 only add this for rk3399-gru.
>
>>> --- a/drivers/spi/spi-rockchip.c
>>> +++ b/drivers/spi/spi-rockchip.c
>
>>> @@ -297,6 +302,50 @@ static void rockchip_spi_set_cs(struct spi_device
>>> *spi, bool enable)
>>> pm_runtime_put_sync(rs->dev);
>>> }
>>> +static int rockchip_spi_setup(struct spi_device *spi)
>>> +{
>>> + int ret = 0;
>>> + unsigned long flags = (spi->mode & SPI_CS_HIGH) ?
>>> + GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH;
>>> + struct rockchip_spi_data *data = spi_get_ctldata(spi);
>>> +
>>> + if (!gpio_is_valid(spi->cs_gpio))
>>> + return 0;
>
>> return -EINVAL?
>
> Isn't this check meant to fall back to hardware CS if no cs-gpios property
> is present?
Thanks for your comment, and yes it is. I'll add a comment in the code
to explain it :)
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
>
>
>
