| Message ID | 20180718235710.18242-3-jmkrzyszt@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 19 Jul 2018 01:57:04 +0200 Janusz Krzysztofik <jmkrzyszt@gmail.com> wrote: > 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 <jmkrzyszt@gmail.com> > --- > 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); Please don't do that until we have a generic way to assert/deassert WP from the core. I agree that we shouldn't write things in the nand_scan() path, but I'd be more comfortable if the core had control on this pin just in case we ever need to disable write-protection during chip detection/initialization. > + > /* 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); >
On Thursday, July 19, 2018 8:22:00 AM CEST Boris Brezillon wrote: > On Thu, 19 Jul 2018 01:57:04 +0200 > Janusz Krzysztofik <jmkrzyszt@gmail.com> wrote: > > > 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 <jmkrzyszt@gmail.com> > > --- > > 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); > > Please don't do that until we have a generic way to assert/deassert WP > from the core. I agree that we shouldn't write things in the > nand_scan() path, but I'd be more comfortable if the core had control > on this pin just in case we ever need to disable write-protection > during chip detection/initialization. OK, I can drop this patch for now if that's what you suggest. Thanks, Janusz
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);
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 <jmkrzyszt@gmail.com> --- drivers/mtd/nand/raw/ams-delta.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)