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mtd: nand: gpio: make nCE GPIO optional 

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>
Reviewed-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
This commit is contained in:
Christophe Leroy 2017-02-10 15:01:10 +01:00 committed by Boris Brezillon
parent 01eb9ae1ae
commit 44dd182861
1 changed files with 12 additions and 6 deletions
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18
drivers/mtd/nand/gpio.c
View File

@ -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,