Re: [PATCH] spi: meson-spicc: Use GPIO descriptors

[Neil Armstrong <narmstrong@xxxxxxxxxxxx>]

On 05/12/2019 09:39, Linus Walleij wrote:
> Instead of grabbing GPIOs using the legacy interface and
> handling them in the setup callback, just let the core
> grab and use the GPIOs using descriptors.
> 
> Cc: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> Cc: Sunny Luo <sunny.luo@xxxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
>  drivers/spi/spi-meson-spicc.c | 25 ++-----------------------
>  1 file changed, 2 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/spi/spi-meson-spicc.c b/drivers/spi/spi-meson-spicc.c
> index f3f10443f9e2..7f5680fe2568 100644
> --- a/drivers/spi/spi-meson-spicc.c
> +++ b/drivers/spi/spi-meson-spicc.c
> @@ -19,7 +19,6 @@
>  #include <linux/types.h>
>  #include <linux/interrupt.h>
>  #include <linux/reset.h>
> -#include <linux/gpio.h>
>  
>  /*
>   * The Meson SPICC controller could support DMA based transfers, but is not
> @@ -467,35 +466,14 @@ static int meson_spicc_unprepare_transfer(struct spi_master *master)
>  
>  static int meson_spicc_setup(struct spi_device *spi)
>  {
> -	int ret = 0;
> -
>  	if (!spi->controller_state)
>  		spi->controller_state = spi_master_get_devdata(spi->master);
> -	else if (gpio_is_valid(spi->cs_gpio))
> -		goto out_gpio;
> -	else if (spi->cs_gpio == -ENOENT)
> -		return 0;
> -
> -	if (gpio_is_valid(spi->cs_gpio)) {
> -		ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev));
> -		if (ret) {
> -			dev_err(&spi->dev, "failed to request cs gpio\n");
> -			return ret;
> -		}
> -	}
> -
> -out_gpio:
> -	ret = gpio_direction_output(spi->cs_gpio,
> -			!(spi->mode & SPI_CS_HIGH));
>  
> -	return ret;
> +	return 0;
>  }
>  
>  static void meson_spicc_cleanup(struct spi_device *spi)
>  {
> -	if (gpio_is_valid(spi->cs_gpio))
> -		gpio_free(spi->cs_gpio);
> -
>  	spi->controller_state = NULL;
>  }
>  
> @@ -564,6 +542,7 @@ static int meson_spicc_probe(struct platform_device *pdev)
>  	master->prepare_message = meson_spicc_prepare_message;
>  	master->unprepare_transfer_hardware = meson_spicc_unprepare_transfer;
>  	master->transfer_one = meson_spicc_transfer_one;
> +	master->use_gpio_descriptors = true;
>  
>  	/* Setup max rate according to the Meson GX datasheet */
>  	if ((rate >> 2) > SPICC_MAX_FREQ)
> 

Hmm, I did this because the SPI core was buggy, so I assume it has been fixed ?

gpio_request/free was not done by the core, thus needing to be done in the setup/cleanup callback.

Neil