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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: Sai Krishna Potthuri <sai.krishna.potthuri@amd.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20220908064428.2962-3-sai.krishna.potthuri@amd.com
This commit is contained in:
Sai Krishna Potthuri 2022-09-08 12:14:28 +05:30 committed by Tudor Ambarus
parent 7f2937efe1
commit 8f1ee9ef71
1 changed files with 25 additions and 0 deletions
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25
drivers/mtd/spi-nor/core.c
View File

@ -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);