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 <sai.krishna.potthuri@xxxxxxx>
> Reviewed-by: Michael Walle <michael@xxxxxxxx>
> ---
> 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
