Re: [PATCH 1/2] spi/bfin_spi: only request GPIO on first load

[Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>]

On Fri, Oct 22, 2010 at 02:01:47AM -0400, Mike Frysinger wrote:
> From: Michael Hennerich <michael.hennerich-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
> 
> The gpiolib code does not allow people to do gpio_request() on a GPIO
> once it has already been requested.  So make sure we only request the
> pin on the first setup of a SPI device.  Otherwise, if you attempts to
> reconfigure a SPI device on the fly (like change bit sizes), the setup
> function incorrectly fails.
> 
> Signed-off-by: Michael Hennerich <michael.hennerich-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Mike Frysinger <vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>

Doesn't that mean that the gpio pin be requested at device probe time
instead of in a function that can be repeatedly called?

g.

> ---
>  drivers/spi/spi_bfin5xx.c |   13 ++++++++-----
>  1 files changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
> index ab483a0..a8f276d 100644
> --- a/drivers/spi/spi_bfin5xx.c
> +++ b/drivers/spi/spi_bfin5xx.c
> @@ -1099,12 +1099,15 @@ static int bfin_spi_setup(struct spi_device *spi)
>  	}
>  
>  	if (chip->chip_select_num >= MAX_CTRL_CS) {
> -		ret = gpio_request(chip->cs_gpio, spi->modalias);
> -		if (ret) {
> -			dev_err(&spi->dev, "gpio_request() error\n");
> -			goto pin_error;
> +		/* Only request on first setup */
> +		if (spi_get_ctldata(spi) == NULL) {
> +			ret = gpio_request(chip->cs_gpio, spi->modalias);
> +			if (ret) {
> +				dev_err(&spi->dev, "gpio_request() error\n");
> +				goto pin_error;
> +			}
> +			gpio_direction_output(chip->cs_gpio, 1);
>  		}
> -		gpio_direction_output(chip->cs_gpio, 1);
>  	}
>  
>  	dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d\n",
> -- 
> 1.7.3.1
>