Commit 8f1ee9ef authored by Sai Krishna Potthuri's avatar Sai Krishna Potthuri Committed by Tudor Ambarus
Browse files

mtd: spi-nor: Add support for flash reset 



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: default avatarSai Krishna Potthuri <sai.krishna.potthuri@amd.com>
Signed-off-by: default avatarTudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: default avatarMichael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20220908064428.2962-3-sai.krishna.potthuri@amd.com
parent 7f2937ef

drivers/mtd/spi-nor/core.c

+25 −0
Original line number Diff line number Diff line
@@ -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);