From mboxrd@z Thu Jan  1 00:00:00 1970
From: radu.pirea@microchip.com (Radu Pirea)
Date: Thu, 24 May 2018 19:04:11 +0300
Subject: [PATCH v3 5/6] spi: at91-usart: add driver for at91-usart as spi
In-Reply-To: <20180517045437.GE20254@sirena.org.uk>
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 <5a3930b867cf8c279953d08c5d5dd1d93113a43b.camel@microchip.com>
 <CAHp75VdRrL25Jgnbk64Qqc5RY3uJdcntJ3xwRdp3F+rRFeTHBA@mail.gmail.com>
 <c23cdde58b9f724f51787c6c38478df983be6efa.camel@microchip.com>
 <20180517045437.GE20254@sirena.org.uk>
Message-ID: <0e6e71e2-f8ac-7889-0d81-8d8a4c15223d@microchip.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org



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?