Messages in this thread Patch in this message | | | From | Christophe Leroy <> | Subject | [PATCH] mtd: nand: gpio: make nCE GPIO optional | Date | Fri, 10 Feb 2017 15:01:10 +0100 (CET) |
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On some hardware, 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.leroy@c-s.fr> --- 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, -- 2.10.1
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