> -----Original Message-----
> From: Oleksij Rempel <[email protected]>
> Sent: Wednesday, October 21, 2020 12:05 PM
> To: Dmitry Torokhov <[email protected]>; Ardelean, Alexandru
> <[email protected]>
> Cc: Oleksij Rempel <[email protected]>; [email protected]; linux-
> [email protected]; [email protected]; David Jander
> <[email protected]>
> Subject: [PATCH v1] Input: ads7846: do not overwrite spi->mode flags set by
> spi
> framework
>
> [External]
>
> Do not overwrite spi->mode flags set by spi framework, otherwise the chip
> select polarity will get lost.
>
> Signed-off-by: Oleksij Rempel <[email protected]>
> ---
> drivers/input/touchscreen/ads7846.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/input/touchscreen/ads7846.c
> b/drivers/input/touchscreen/ads7846.c
> index 8fd7fc39c4fd..ea31956f3a90 100644
> --- a/drivers/input/touchscreen/ads7846.c
> +++ b/drivers/input/touchscreen/ads7846.c
> @@ -1288,7 +1288,7 @@ static int ads7846_probe(struct spi_device *spi)
> * may not. So we stick to very-portable 8 bit words, both RX and TX.
> */
> spi->bits_per_word = 8;
> - spi->mode = SPI_MODE_0;
I think the patch is incorrect.
The initial version is correct; assuming that the datasheet says that this
driver operates in mode 0.
If the initial mode is incorrect, maybe we need to change that.
What is unfortunate, is that you cannot [yet] override the mode parameters
[polarity & phase] from the device-tree, in case there are some things
in-between the SPI controller & SPI chip [level inverters for example].
I was planning to do something for this.
> + spi->mode |= SPI_MODE_0;
> err = spi_setup(spi);
> if (err < 0)
> return err;
> --
> 2.28.0
