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SubjectRe: [PATCH v3 5/6] spi: at91-usart: add driver for at91-usart as spi
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On 05/17/2018 07:54 AM, Mark Brown wrote:
> On Tue, May 15, 2018 at 12:22:24PM +0300, Radu Pirea wrote:
>> On Mon, 2018-05-14 at 20:38 +0300, Andy Shevchenko wrote:
>
>>> So, what is not going as expected in "SPI core takes care of CSs"
>>> case?
>>> Did you use oscilloscope for that?
>
>> Yes, I used and CSs was not asserted. Anyway, I will will try again.
>
> If the core chip select handling is not working properly for some reason
> then the core chip select handling should be fixed rather than just open
> coding in your driver - probably it's also broken for other users.
>

Hi Mark,

I found the fix for cs-gpios. If I change spi_add_device function like
this(see below) everything is ok.

int spi_add_device(struct spi_device *spi)

...

if (ctlr->cs_gpios){
spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
if(gpio_is_valid(spi->cs_gpio))
gpio_direction_output(spi->cs_gpio, !(spi->mode &
SPI_CS_HIGH));

}

...

return status;
}

In the subsystem gpio direction of pins is never set and
gpio_set_value() don't set the direction.
In my opinion gpio_direction_output() set direction should be called in
spi_add_device. What do you think? Is ok?

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