From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Boris Brezillon <boris.brezillon@free-electrons.com>,
Richard Weinberger <richard@nod.at>,
David Woodhouse <dwmw2@infradead.org>,
Brian Norris <computersforpeace@gmail.com>,
Marek Vasut <marek.vasut@gmail.com>,
Cyrille Pitchen <cyrille.pitchen@atmel.com>
Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] mtd: nand: gpio: make nCE GPIO optional
Date: Fri, 10 Feb 2017 15:01:10 +0100 (CET) [thread overview]
Message-ID: <20170210140110.87903682E7@localhost.localdomain> (raw)
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
next reply other threads:[~2017-02-10 14:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-10 14:01 Christophe Leroy [this message]
2017-02-10 15:12 ` [PATCH] mtd: nand: gpio: make nCE GPIO optional Marek Vasut
2017-02-13 10:30 ` Boris Brezillon
2017-02-13 12:58 ` Christophe LEROY
2017-02-13 13:22 ` Boris Brezillon
2017-03-16 9:35 ` Boris Brezillon
2017-05-01 21:46 ` Brian Norris
2017-05-02 5:47 ` Christophe LEROY
2017-05-02 9:03 ` Boris Brezillon
2017-05-02 16:15 ` Brian Norris
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