From mboxrd@z Thu Jan 1 00:00:00 1970 From: Janusz Krzysztofik To: Boris Brezillon , Miquel Raynal Cc: Tony Lindgren , Aaro Koskinen , Grygorii Strashko , Santosh Shilimkar , Kevin Hilman , Linus Walleij , Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , linux-mtd@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Artem Bityutskiy , Janusz Krzysztofik Subject: [RFC PATCH 2/8] mtd: rawnand: ams-delta: Write protect device during probe Date: Thu, 19 Jul 2018 01:57:04 +0200 Message-Id: <20180718235710.18242-3-jmkrzyszt@gmail.com> In-Reply-To: <20180718235710.18242-1-jmkrzyszt@gmail.com> References: <20180718235710.18242-1-jmkrzyszt@gmail.com> List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Initialize NWP GPIO pin low to protect the device from hazard during probe. Release write protection as soon as the device is under control. Signed-off-by: Janusz Krzysztofik --- drivers/mtd/nand/raw/ams-delta.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/nand/raw/ams-delta.c b/drivers/mtd/nand/raw/ams-delta.c index 48233d638d2a..6ac38e9cfa1a 100644 --- a/drivers/mtd/nand/raw/ams-delta.c +++ b/drivers/mtd/nand/raw/ams-delta.c @@ -219,8 +219,8 @@ static int ams_delta_init(struct platform_device *pdev) platform_set_drvdata(pdev, priv); - /* Set chip enabled, but */ - priv->gpiod_nwp = devm_gpiod_get(&pdev->dev, "nwp", GPIOD_OUT_HIGH); + /* Set chip enabled but write protected */ + priv->gpiod_nwp = devm_gpiod_get(&pdev->dev, "nwp", GPIOD_OUT_LOW); if (IS_ERR(priv->gpiod_nwp)) { err = PTR_ERR(priv->gpiod_nwp); dev_err(&pdev->dev, "NWP GPIO request failed (%d)\n", err); @@ -267,6 +267,9 @@ static int ams_delta_init(struct platform_device *pdev) if (err) goto out_mtd; + /* As soon as the device is found, release write protection */ + gpiod_set_value(priv->gpiod_nwp, 1); + /* Register the partitions */ mtd_device_register(mtd, partition_info, ARRAY_SIZE(partition_info)); @@ -288,6 +291,9 @@ static int ams_delta_cleanup(struct platform_device *pdev) struct mtd_info *mtd = nand_to_mtd(&priv->nand_chip); void __iomem *io_base = priv->io_base; + /* Apply write protection */ + gpiod_set_value(priv->gpiod_nwp, 0); + /* Release resources, unregister device */ nand_release(mtd); -- 2.16.4