diff options
| author | Janusz Krzysztofik <jmkrzyszt@gmail.com> | 2020-02-12 03:39:16 +0300 |
|---|---|---|
| committer | Miquel Raynal <miquel.raynal@bootlin.com> | 2020-03-09 16:51:01 +0300 |
| commit | 91a1abfb752357fe5d0783bd69db0d91f358e3eb (patch) | |
| tree | 372ae59651f12245f3d11e3043ac80835d2674a0 /drivers/mtd/nand | |
| parent | c4b7dd35d35936964c71db42e1d94994ee6ea411 (diff) | |
| download | linux-91a1abfb752357fe5d0783bd69db0d91f358e3eb.tar.xz | |
mtd: rawnand: ams-delta: Write protect device during probe
Initialise NWP GPIO pin as asserted to protect the device from hazard
during setup of other GPIO pins.
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200212003929.6682-2-jmkrzyszt@gmail.com
Diffstat (limited to 'drivers/mtd/nand')
| -rw-r--r-- | drivers/mtd/nand/raw/ams-delta.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/mtd/nand/raw/ams-delta.c b/drivers/mtd/nand/raw/ams-delta.c index 8312182088c1..2501cfe00f43 100644 --- a/drivers/mtd/nand/raw/ams-delta.c +++ b/drivers/mtd/nand/raw/ams-delta.c @@ -251,8 +251,8 @@ 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); @@ -309,6 +309,17 @@ static int ams_delta_init(struct platform_device *pdev) nand_controller_init(&priv->base); this->controller = &priv->base; + /* + * FIXME: We should release write protection only after nand_scan() to + * be on the safe side but we can't do that until we have a generic way + * to assert/deassert WP from the core. Even if the core shouldn't + * write things in the nand_scan() path, it should have control on this + * pin just in case we ever need to disable write protection during + * chip detection/initialization. + */ + /* Release write protection */ + gpiod_set_value(priv->gpiod_nwp, 1); + /* Scan to find existence of the device */ err = nand_scan(this, 1); if (err) @@ -336,6 +347,9 @@ static int ams_delta_cleanup(struct platform_device *pdev) struct ams_delta_nand *priv = platform_get_drvdata(pdev); struct mtd_info *mtd = nand_to_mtd(&priv->nand_chip); + /* Apply write protection */ + gpiod_set_value(priv->gpiod_nwp, 0); + /* Unregister device */ nand_release(mtd_to_nand(mtd)); |