From: Janusz Krzysztofik <jmkrzyszt@gmail.com>
To: Miquel Raynal <miquel.raynal@bootlin.com>,
Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>,
Aaro Koskinen <aaro.koskinen@iki.fi>,
Tony Lindgren <tony@atomide.com>,
Janusz Krzysztofik <jmkrzyszt@gmail.com>,
linux-mtd@lists.infradead.org, linux-omap@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 01/14 v2] mtd: rawnand: ams-delta: Write protect device during probe
Date: Wed, 12 Feb 2020 01:39:16 +0100 [thread overview]
Message-ID: <20200212003929.6682-2-jmkrzyszt@gmail.com> (raw)
In-Reply-To: <20200212003929.6682-1-jmkrzyszt@gmail.com>
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>
---
v2: release write protection before calling nand_scan()
drivers/mtd/nand/raw/ams-delta.c | 18 ++++++++++++++++--
1 file 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));
--
2.24.1
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next prev parent reply other threads:[~2020-02-12 0:41 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-12 0:39 [RFC PATCH 00/14] mtd: rawnand: ams-delta: Prepare for merging Janusz Krzysztofik
2020-02-12 0:39 ` Janusz Krzysztofik [this message]
2020-03-10 18:33 ` [RFC PATCH 01/14 v2] mtd: rawnand: ams-delta: Write protect device during probe Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 02/14] mtd: rawnand: ams-delta: Use struct gpio_nand_platdata Janusz Krzysztofik
2020-03-10 18:33 ` Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 03/14] ARM: OMAP1: ams-delta: Provide board specific partition info Janusz Krzysztofik
2020-02-12 14:51 ` Tony Lindgren
2020-02-12 18:25 ` Janusz Krzysztofik
2020-02-12 18:28 ` Tony Lindgren
2020-03-10 18:33 ` Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 04/14 v4] mtd: rawnand: ams-delta: Drop " Janusz Krzysztofik
2020-03-10 18:33 ` Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 05/14] mtd: rawnand: ams-delta: Enable OF partition info support Janusz Krzysztofik
2020-03-10 18:33 ` Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 06/14] mtd: rawnand: ams-delta: Push inversion handling to gpiolib Janusz Krzysztofik
2020-02-12 18:28 ` Tony Lindgren
2020-03-10 18:32 ` Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 07/14] mtd: rawnand: ams-delta: Don't hardcode read/write pulse widths Janusz Krzysztofik
2020-03-10 18:32 ` Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 08/14] mtd: rawnand: ams-delta: Make read pulses optional Janusz Krzysztofik
2020-03-10 18:32 ` Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 09/14] mtd: rawnand: ams-delta: Handle more GPIO pins as optional Janusz Krzysztofik
2020-03-10 18:32 ` Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 10/14] mtd: rawnand: ams-delta: Add module device tables Janusz Krzysztofik
2020-03-10 18:32 ` Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 11/14] mtd: rawnand: ams-delta: Support custom driver initialisation Janusz Krzysztofik
2020-03-10 18:32 ` Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 12/14] mtd: rawnand: ams-delta: Drop useless local variable Janusz Krzysztofik
2020-03-10 18:32 ` Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 13/14] mtd: rawnand: ams-delta: Make the driver custom I/O ready Janusz Krzysztofik
2020-03-10 18:32 ` Miquel Raynal
2020-02-12 0:39 ` [RFC PATCH 14/14] mtd: rawnand: ams-delta: Rename structures and functions to gpio_nand* Janusz Krzysztofik
2020-03-10 18:32 ` Miquel Raynal
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