Hi, Am 2022-08-29 11:05, schrieb Sai Krishna Potthuri:
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> --- drivers/mtd/spi-nor/core.c | 50 +++++++++++++++++++++++++++++++++++--- 1 file changed, 46 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index f2c64006f8d7..d4703ff69ad0 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -2401,12 +2401,8 @@ static void spi_nor_no_sfdp_init_params(struct spi_nor *nor) */ static void spi_nor_init_flags(struct spi_nor *nor) { - struct device_node *np = spi_nor_get_flash_node(nor); const u16 flags = nor->info->flags; - if (of_property_read_bool(np, "broken-flash-reset")) - nor->flags |= SNOR_F_BROKEN_RESET; - if (flags & SPI_NOR_SWP_IS_VOLATILE) nor->flags |= SNOR_F_SWP_IS_VOLATILE;@@ -2933,9 +2929,47 @@ 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; + int ret; + + reset = devm_gpiod_get_optional(nor->dev, "reset", GPIOD_ASIS);
devm_gpiod_get_optional(nor->dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR_OR_NULL(reset)) + return PTR_ERR_OR_ZERO(reset); + + /* Set the direction as output and enable the output */ + ret = gpiod_direction_output(reset, 1);
Not necessary then.
+ if (ret) + return ret; + + /* + * Experimental Minimum Chip select high to Reset delay value + * based on the flash device spec. + */
Which flash device spec?
+ usleep_range(1, 5); + gpiod_set_value(reset, 0);
Mh, is your logic inverted here? If I read the code correctly, you should use a value of 1 to take the device into reset. The device tree should then have a flag "active low", which will invert the value here. Also please use the cansleep() variant.
+ /* + * Experimental Minimum Reset pulse width value based on the + * flash device spec. + */ + usleep_range(10, 15); + gpiod_set_value(reset, 1); + + /* + * Experimental Minimum Reset recovery delay value based on the + * flash device spec. + */ + usleep_range(35, 40); + + return 0; +} + int spi_nor_scan(struct spi_nor *nor, const char *name, const struct spi_nor_hwcaps *hwcaps) { + struct device_node *np = spi_nor_get_flash_node(nor); const struct flash_info *info; struct device *dev = nor->dev; struct mtd_info *mtd = &nor->mtd;@@ -2965,6 +2999,14 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,if (!nor->bouncebuf) return -ENOMEM; + if (of_property_read_bool(np, "broken-flash-reset")) { + nor->flags |= SNOR_F_BROKEN_RESET; + } else { + ret = spi_nor_hw_reset(nor); + if (ret) + return ret; + }
This should be done unconditionally, no? Even if the reset pin is broken, we know we have one (otherwise the device tree would be broken) and we can do a reset in any case. Also, which tree are you using? That was moved into spi_nor_init_flags() some time ago. Please rebase to latest spi-next. -michael
+ info = spi_nor_get_flash_info(nor, name); if (IS_ERR(info)) return PTR_ERR(info);
