Re: [PATCH 7/7 v1] spi: dw: Convert to use CS GPIO descriptors

[Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>]

On 16/12/2018 00:38:23+0100, Linus Walleij wrote:
> This converts the DesignWare (dw) SPI master driver to
> use GPIO descriptors for chip select handling.
> 
> This driver has a duplicate DT parser in addition to the
> one in the core, sets up the line as non-asserted and
> relies on the core to drive the GPIOs.
> 
> It is a pretty straight-forward conversion.
> 
> Cc: Talel Shenhar <talel@xxxxxxxxxx>
> Cc: Simon Goldschmidt <simon.k.r.goldschmidt@xxxxxxxxx>
> Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
> Cc: Linuxarm <linuxarm@xxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

The core part was on my todo list since early 2014, thank you to take
care of that :)

Reviewed-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>

> ---
>  drivers/spi/spi-dw-mmio.c | 22 ----------------------
>  drivers/spi/spi-dw.c      |  9 +--------
>  2 files changed, 1 insertion(+), 30 deletions(-)
> 
> diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
> index 3ffb6a40fe0c..00a43c19f2a4 100644
> --- a/drivers/spi/spi-dw-mmio.c
> +++ b/drivers/spi/spi-dw-mmio.c
> @@ -18,7 +18,6 @@
>  #include <linux/mfd/syscon.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> -#include <linux/of_gpio.h>
>  #include <linux/of_platform.h>
>  #include <linux/property.h>
>  #include <linux/regmap.h>
> @@ -184,27 +183,6 @@ static int dw_spi_mmio_probe(struct platform_device *pdev)
>  
>  	dws->num_cs = num_cs;
>  
> -	if (pdev->dev.of_node) {
> -		int i;
> -
> -		for (i = 0; i < dws->num_cs; i++) {
> -			int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
> -					"cs-gpios", i);
> -
> -			if (cs_gpio == -EPROBE_DEFER) {
> -				ret = cs_gpio;
> -				goto out;
> -			}
> -
> -			if (gpio_is_valid(cs_gpio)) {
> -				ret = devm_gpio_request(&pdev->dev, cs_gpio,
> -						dev_name(&pdev->dev));
> -				if (ret)
> -					goto out;
> -			}
> -		}
> -	}
> -
>  	init_func = device_get_match_data(&pdev->dev);
>  	if (init_func) {
>  		ret = init_func(pdev, dwsmmio);
> diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
> index b705f2bdb8b9..22a7998dbc08 100644
> --- a/drivers/spi/spi-dw.c
> +++ b/drivers/spi/spi-dw.c
> @@ -20,7 +20,6 @@
>  #include <linux/delay.h>
>  #include <linux/slab.h>
>  #include <linux/spi/spi.h>
> -#include <linux/gpio.h>
>  
>  #include "spi-dw.h"
>  
> @@ -425,13 +424,6 @@ static int dw_spi_setup(struct spi_device *spi)
>  
>  	chip->tmode = SPI_TMOD_TR;
>  
> -	if (gpio_is_valid(spi->cs_gpio)) {
> -		ret = gpio_direction_output(spi->cs_gpio,
> -				!(spi->mode & SPI_CS_HIGH));
> -		if (ret)
> -			return ret;
> -	}
> -
>  	return 0;
>  }
>  
> @@ -496,6 +488,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
>  		goto err_free_master;
>  	}
>  
> +	master->use_gpio_descriptors = true;
>  	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
>  	master->bits_per_word_mask =  SPI_BPW_RANGE_MASK(4, 16);
>  	master->bus_num = dws->bus_num;
> -- 
> 2.19.2
> 

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com