On 02/10/2017 03:01 PM, Christophe Leroy wrote:
> On some hardware,
Can you be more specific or is that confidential ? Anyway, that's just
my curiosity, what hardware is done like that.
> the nCE signal is wired to the ChipSelect associated
> to bus address of the NAND, so it is automatically driven during the
> memory access and it is not managed by a GPIO.
>
> Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
Reviewed-by: Marek Vasut <marek.va...@gmail.com>
but please wait for the NAND experts ...
> ---
> drivers/mtd/nand/gpio.c | 18 ++++++++++++------
> 1 file changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mtd/nand/gpio.c b/drivers/mtd/nand/gpio.c
> index 0d24857..85294f1 100644
> --- a/drivers/mtd/nand/gpio.c
> +++ b/drivers/mtd/nand/gpio.c
> @@ -78,7 +78,9 @@ static void gpio_nand_cmd_ctrl(struct mtd_info *mtd, int
> cmd, unsigned int ctrl)
> gpio_nand_dosync(gpiomtd);
>
> if (ctrl & NAND_CTRL_CHANGE) {
> - gpio_set_value(gpiomtd->plat.gpio_nce, !(ctrl & NAND_NCE));
> + if (gpio_is_valid(gpiomtd->plat.gpio_nce))
> + gpio_set_value(gpiomtd->plat.gpio_nce,
> + !(ctrl & NAND_NCE));
> gpio_set_value(gpiomtd->plat.gpio_cle, !!(ctrl & NAND_CLE));
> gpio_set_value(gpiomtd->plat.gpio_ale, !!(ctrl & NAND_ALE));
> gpio_nand_dosync(gpiomtd);
> @@ -201,7 +203,8 @@ static int gpio_nand_remove(struct platform_device *pdev)
>
> if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
> gpio_set_value(gpiomtd->plat.gpio_nwp, 0);
> - gpio_set_value(gpiomtd->plat.gpio_nce, 1);
> + if (gpio_is_valid(gpiomtd->plat.gpio_nce))
> + gpio_set_value(gpiomtd->plat.gpio_nce, 1);
>
> return 0;
> }
> @@ -239,10 +242,13 @@ static int gpio_nand_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> - ret = devm_gpio_request(&pdev->dev, gpiomtd->plat.gpio_nce, "NAND NCE");
> - if (ret)
> - return ret;
> - gpio_direction_output(gpiomtd->plat.gpio_nce, 1);
> + if (gpio_is_valid(gpiomtd->plat.gpio_nce)) {
> + ret = devm_gpio_request(&pdev->dev, gpiomtd->plat.gpio_nce,
> + "NAND NCE");
> + if (ret)
> + return ret;
> + gpio_direction_output(gpiomtd->plat.gpio_nce, 1);
> + }
>
> if (gpio_is_valid(gpiomtd->plat.gpio_nwp)) {
> ret = devm_gpio_request(&pdev->dev, gpiomtd->plat.gpio_nwp,
>
--
Best regards,
Marek Vasut
