[PATCH v2] spi: Ensure that CS line is in non-active state after spi_setup()

[PATCH v2] spi: Ensure that CS line is in non-active state after spi_setup()

[Ivan T. Ivanov]

Some devices samples state of the chip select signal during power up
and act differently based on this state, so SPI core should ensure
that CS line is driven in non-active state after spi_setup().

Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
---
 drivers/spi/spi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index c64a3e5..4023cc9 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1893,6 +1893,8 @@ int spi_setup(struct spi_device *spi)
 	if (!spi->max_speed_hz)
 		spi->max_speed_hz = spi->master->max_speed_hz;

+	spi_set_cs(spi, false);
+
 	if (spi->master->setup)
 		status = spi->master->setup(spi);

--
1.9.1

Re: [PATCH v2] spi: Ensure that CS line is in non-active state after spi_setup()

[Ivan T. Ivanov]

On Fri, 2015-03-13 at 18:43 +0200, Ivan T. Ivanov wrote:
> Some devices samples state of the chip select signal during power up
> and act differently based on this state, so SPI core should ensure
> that CS line is driven in non-active state after spi_setup().
> 
> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
> ---

Any comments on this one?

Forget to add changes since v1 [1].

CS is set to non-active state unconditionally before
spi->master->setup()

Regards,
Ivan

[1] http://www.spinics.net/lists/linux-spi/msg03056.html

>  drivers/spi/spi.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index c64a3e5..4023cc9 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -1893,6 +1893,8 @@ int spi_setup(struct spi_device *spi)
>         if (!spi->max_speed_hz)
>                 spi->max_speed_hz = spi->master->max_speed_hz;
> 
> +       spi_set_cs(spi, false);
> +
>         if (spi->master->setup)
>                 status = spi->master->setup(spi);
> 

Re: [PATCH v2] spi: Ensure that CS line is in non-active state after spi_setup()

[Mark Brown]

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On Fri, Mar 20, 2015 at 06:14:49PM +0200, Ivan T. Ivanov wrote:

> Any comments on this one?

> Forget to add changes since v1 [1].

> CS is set to non-active state unconditionally before
> spi->master->setup()

Please don't send content free quoted pings.

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