Add support for spi-nor flash reset via GPIO controller by reading the
reset-gpio property. If there is a valid GPIO specifier then reset will
be performed by asserting and deasserting the GPIO using gpiod APIs
otherwise it will not perform any operation.
Signed-off-by: Sai Krishna Potthuri <[email protected]>
Reviewed-by: Michael Walle <[email protected]>
---
drivers/mtd/spi-nor/core.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index f2c64006f8d7..a78ab9bae2be 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -2933,6 +2933,27 @@ static void spi_nor_set_mtd_info(struct spi_nor *nor)
mtd->_put_device = spi_nor_put_device;
}
+static int spi_nor_hw_reset(struct spi_nor *nor)
+{
+ struct gpio_desc *reset;
+
+ reset = devm_gpiod_get_optional(nor->dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR_OR_NULL(reset))
+ return PTR_ERR_OR_ZERO(reset);
+
+ /*
+ * Experimental delay values by looking at different flash device
+ * vendors datasheets.
+ */
+ usleep_range(1, 5);
+ gpiod_set_value_cansleep(reset, 1);
+ usleep_range(100, 150);
+ gpiod_set_value_cansleep(reset, 0);
+ usleep_range(1000, 1200);
+
+ return 0;
+}
+
int spi_nor_scan(struct spi_nor *nor, const char *name,
const struct spi_nor_hwcaps *hwcaps)
{
@@ -2965,6 +2986,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
if (!nor->bouncebuf)
return -ENOMEM;
+ ret = spi_nor_hw_reset(nor);
+ if (ret)
+ return ret;
+
info = spi_nor_get_flash_info(nor, name);
if (IS_ERR(info))
return PTR_ERR(info);
--
2.17.1
On 9/8/22 09:44, Sai Krishna Potthuri wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> Add support for spi-nor flash reset via GPIO controller by reading the
> reset-gpio property. If there is a valid GPIO specifier then reset will
> be performed by asserting and deasserting the GPIO using gpiod APIs
> otherwise it will not perform any operation.
>
> Signed-off-by: Sai Krishna Potthuri <[email protected]>
> Reviewed-by: Michael Walle <[email protected]>
> ---
> drivers/mtd/spi-nor/core.c | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index f2c64006f8d7..a78ab9bae2be 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -2933,6 +2933,27 @@ static void spi_nor_set_mtd_info(struct spi_nor *nor)
> mtd->_put_device = spi_nor_put_device;
> }
>
> +static int spi_nor_hw_reset(struct spi_nor *nor)
> +{
> + struct gpio_desc *reset;
> +
> + reset = devm_gpiod_get_optional(nor->dev, "reset", GPIOD_OUT_LOW);
> + if (IS_ERR_OR_NULL(reset))
> + return PTR_ERR_OR_ZERO(reset);
> +
> + /*
> + * Experimental delay values by looking at different flash device
> + * vendors datasheets.
> + */
> + usleep_range(1, 5);
> + gpiod_set_value_cansleep(reset, 1);
> + usleep_range(100, 150);
> + gpiod_set_value_cansleep(reset, 0);
> + usleep_range(1000, 1200);
> +
> + return 0;
> +}
> +
> int spi_nor_scan(struct spi_nor *nor, const char *name,
> const struct spi_nor_hwcaps *hwcaps)
> {
> @@ -2965,6 +2986,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
> if (!nor->bouncebuf)
> return -ENOMEM;
>
> + ret = spi_nor_hw_reset(nor);
Should we condition the calling of this method by the absence of the "broken-flash-reset"
dt prop?
> + if (ret)
> + return ret;
> +
> info = spi_nor_get_flash_info(nor, name);
> if (IS_ERR(info))
> return PTR_ERR(info);
> --
> 2.17.1
>
--
Cheers,
ta
Hi Tudor Ambarus,
> -----Original Message-----
> From: [email protected] <[email protected]>
> Sent: Monday, October 3, 2022 3:13 PM
> To: Potthuri, Sai Krishna <[email protected]>;
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]
> Cc: [email protected]; [email protected]; linux-
> [email protected]; [email protected]; git (AMD-Xilinx)
> <[email protected]>
> Subject: Re: [PATCH v3 2/2] mtd: spi-nor: Add support for flash reset
>
> On 9/8/22 09:44, Sai Krishna Potthuri wrote:
> > EXTERNAL EMAIL: Do not click links or open attachments unless you know
> > the content is safe
> >
> > Add support for spi-nor flash reset via GPIO controller by reading the
> > reset-gpio property. If there is a valid GPIO specifier then reset
> > will be performed by asserting and deasserting the GPIO using gpiod
> > APIs otherwise it will not perform any operation.
> >
> > Signed-off-by: Sai Krishna Potthuri <[email protected]>
> > Reviewed-by: Michael Walle <[email protected]>
> > ---
> > drivers/mtd/spi-nor/core.c | 25 +++++++++++++++++++++++++
> > 1 file changed, 25 insertions(+)
> >
> > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> > index f2c64006f8d7..a78ab9bae2be 100644
> > --- a/drivers/mtd/spi-nor/core.c
> > +++ b/drivers/mtd/spi-nor/core.c
> > @@ -2933,6 +2933,27 @@ static void spi_nor_set_mtd_info(struct spi_nor
> *nor)
> > mtd->_put_device = spi_nor_put_device; }
> >
> > +static int spi_nor_hw_reset(struct spi_nor *nor) {
> > + struct gpio_desc *reset;
> > +
> > + reset = devm_gpiod_get_optional(nor->dev, "reset",
> GPIOD_OUT_LOW);
> > + if (IS_ERR_OR_NULL(reset))
> > + return PTR_ERR_OR_ZERO(reset);
> > +
> > + /*
> > + * Experimental delay values by looking at different flash device
> > + * vendors datasheets.
> > + */
> > + usleep_range(1, 5);
> > + gpiod_set_value_cansleep(reset, 1);
> > + usleep_range(100, 150);
> > + gpiod_set_value_cansleep(reset, 0);
> > + usleep_range(1000, 1200);
> > +
> > + return 0;
> > +}
> > +
> > int spi_nor_scan(struct spi_nor *nor, const char *name,
> > const struct spi_nor_hwcaps *hwcaps) { @@ -2965,6
> > +2986,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
> > if (!nor->bouncebuf)
> > return -ENOMEM;
> >
> > + ret = spi_nor_hw_reset(nor);
>
> Should we condition the calling of this method by the absence of the
> "broken-flash-reset"
> dt prop?
This is the suggestion from Michael on top of my initial series for which
i also agreed to have this call unconditionally. If device tree is having this
reset property then we can do the reset in any case.
Regards
Sai Krishna
On 10/3/22 13:06, Potthuri, Sai Krishna wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> Hi Tudor Ambarus,
>
>> -----Original Message-----
>> From: [email protected] <[email protected]>
>> Sent: Monday, October 3, 2022 3:13 PM
>> To: Potthuri, Sai Krishna <[email protected]>;
>> [email protected]; [email protected]; [email protected];
>> [email protected]; [email protected]; [email protected];
>> [email protected]
>> Cc: [email protected]; [email protected]; linux-
>> [email protected]; [email protected]; git (AMD-Xilinx)
>> <[email protected]>
>> Subject: Re: [PATCH v3 2/2] mtd: spi-nor: Add support for flash reset
>>
>> On 9/8/22 09:44, Sai Krishna Potthuri wrote:
>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know
>>> the content is safe
>>>
>>> Add support for spi-nor flash reset via GPIO controller by reading the
>>> reset-gpio property. If there is a valid GPIO specifier then reset
>>> will be performed by asserting and deasserting the GPIO using gpiod
>>> APIs otherwise it will not perform any operation.
>>>
>>> Signed-off-by: Sai Krishna Potthuri <[email protected]>
>>> Reviewed-by: Michael Walle <[email protected]>
>>> ---
>>> drivers/mtd/spi-nor/core.c | 25 +++++++++++++++++++++++++
>>> 1 file changed, 25 insertions(+)
>>>
>>> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
>>> index f2c64006f8d7..a78ab9bae2be 100644
>>> --- a/drivers/mtd/spi-nor/core.c
>>> +++ b/drivers/mtd/spi-nor/core.c
>>> @@ -2933,6 +2933,27 @@ static void spi_nor_set_mtd_info(struct spi_nor
>> *nor)
>>> mtd->_put_device = spi_nor_put_device; }
>>>
>>> +static int spi_nor_hw_reset(struct spi_nor *nor) {
>>> + struct gpio_desc *reset;
>>> +
>>> + reset = devm_gpiod_get_optional(nor->dev, "reset",
>> GPIOD_OUT_LOW);
>>> + if (IS_ERR_OR_NULL(reset))
>>> + return PTR_ERR_OR_ZERO(reset);
>>> +
>>> + /*
>>> + * Experimental delay values by looking at different flash device
>>> + * vendors datasheets.
>>> + */
>>> + usleep_range(1, 5);
>>> + gpiod_set_value_cansleep(reset, 1);
>>> + usleep_range(100, 150);
>>> + gpiod_set_value_cansleep(reset, 0);
>>> + usleep_range(1000, 1200);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> int spi_nor_scan(struct spi_nor *nor, const char *name,
>>> const struct spi_nor_hwcaps *hwcaps) { @@ -2965,6
>>> +2986,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
>>> if (!nor->bouncebuf)
>>> return -ENOMEM;
>>>
>>> + ret = spi_nor_hw_reset(nor);
>>
>> Should we condition the calling of this method by the absence of the
>> "broken-flash-reset"
>> dt prop?
> This is the suggestion from Michael on top of my initial series for which
> i also agreed to have this call unconditionally. If device tree is having this
> reset property then we can do the reset in any case.
>
Okay.
--
Cheers,
ta