From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pegase1.c-s.fr ([93.17.236.30]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1ccBla-0000El-El for linux-mtd@lists.infradead.org; Fri, 10 Feb 2017 14:01:44 +0000 From: Christophe Leroy Subject: [PATCH] mtd: nand: gpio: make nCE GPIO optional To: Boris Brezillon , Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Cyrille Pitchen Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Message-Id: <20170210140110.87903682E7@localhost.localdomain> Date: Fri, 10 Feb 2017 15:01:10 +0100 (CET) List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 --- 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