Add support for spi-nor flash reset via GPIO controller
by reading the reset-gpios property.
[Ported from Linux kernel commit
8f1ee9ef71d0 ("mtd: spi-nor: Add support for flash reset") ]
Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbar...@amd.com>
---
Changes in v2:
- Removed the code from spi_nor_remove() as gpio descriptor is
managed by DEVRES.
---
drivers/mtd/spi/spi-nor-core.c | 38 ++++++++++++++++++++++++++++++++++
include/linux/mtd/spi-nor.h | 1 +
2 files changed, 39 insertions(+)
diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index ec841fb13b..93a7d046c0 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -12,6 +12,7 @@
#include <display_options.h>
#include <log.h>
#include <watchdog.h>
+#include <asm/gpio.h>
#include <dm.h>
#include <dm/device_compat.h>
#include <dm/devres.h>
@@ -4415,6 +4416,37 @@ void spi_nor_set_fixups(struct spi_nor *nor)
#endif /* SPI_FLASH_MACRONIX */
}
+static int spi_nor_hw_reset(struct spi_nor *nor)
+{
+ struct udevice *dev = nor->spi->dev;
+ int rc;
+
+ nor->flash_gpio_reset = devm_gpiod_get_optional(dev, "reset",
+ GPIOD_IS_OUT |
GPIOD_ACTIVE_LOW);
+
+ if (nor->flash_gpio_reset) {
+ /*
+ * Experimental delay values by looking at different flash
device
+ * vendors datasheets.
+ */
+ udelay(5);
+
+ /* Toggle gpio to reset the flash device. */
+ rc = dm_gpio_set_value(nor->flash_gpio_reset, 1);
+ if (rc)
+ return rc;
+
+ udelay(150);
+
+ rc = dm_gpio_set_value(nor->flash_gpio_reset, 0);
+ if (rc)
+ return rc;
+
+ udelay(1200);
+ }
+ return 0;
+}
+
int spi_nor_scan(struct spi_nor *nor)
{
struct spi_nor_flash_parameter params;
@@ -4440,6 +4472,12 @@ int spi_nor_scan(struct spi_nor *nor)
nor->setup = spi_nor_default_setup;
+ if (CONFIG_IS_ENABLED(DM_GPIO)) {
+ ret = spi_nor_hw_reset(nor);
+ if (ret)
+ return ret;
+ }
+
#ifdef CONFIG_SPI_FLASH_SOFT_RESET_ON_BOOT
/*
* When the flash is handed to us in a stateful mode like 8D-8D-8D, it
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index b8b207f7b5..eb2e9c90b2 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -583,6 +583,7 @@ struct spi_nor {
u8 cmd_buf[SPI_NOR_MAX_CMD_SIZE];
enum spi_nor_cmd_ext cmd_ext_type;
struct spi_nor_fixups *fixups;
+ struct gpio_desc *flash_gpio_reset;
int (*setup)(struct spi_nor *nor, const struct flash_info *info,
const struct spi_nor_flash_parameter *params);
--
2.17.1
