[RFC PATCH 4/5] mtd: spi: sf: implement .on_reset method

[Robert Marko]

Implement .on_reset method for SPI flash, by extending the remove method
to exit 4-byte adressing mode in case it was entered before.

This fixes the issue with 4-byte adressing mode being left enabled on
board reset.
That is an issue on Qualcomm IPQ4019 boards since the CPU expects flash
to be in 3-byte adressing mode and will just hang otherwise.

Note that this does not fix a case where you remove the power while U-Boot
is still running and in that case it will still be stuck in 4-byte mode.

Signed-off-by: Robert Marko <robert.marko at sartura.hr>
---
 drivers/mtd/spi/sf_probe.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
index de6516f106..31dae17ba0 100644
--- a/drivers/mtd/spi/sf_probe.c
+++ b/drivers/mtd/spi/sf_probe.c
@@ -225,6 +225,15 @@ static int spi_flash_std_remove(struct udevice *dev)
 	struct spi_flash *flash = dev_get_uclass_priv(dev);
 	int ret;
 
+	if (flash->addr_width == 4 &&
+	    !(flash->info->flags & SPI_NOR_OCTAL_DTR_READ) &&
+	    (JEDEC_MFR(flash->info) != SNOR_MFR_SPANSION) &&
+	    !(flash->flags & SNOR_F_4B_OPCODES)) {
+		ret = spi_nor_set_4byte(flash, flash->info, 0);
+		if (ret)
+			return ret;
+	}
+
 	if (CONFIG_IS_ENABLED(SPI_DIRMAP)) {
 		spi_mem_dirmap_destroy(flash->dirmap.wdesc);
 		spi_mem_dirmap_destroy(flash->dirmap.rdesc);
@@ -258,6 +267,7 @@ U_BOOT_DRIVER(jedec_spi_nor) = {
 	.of_match	= spi_flash_std_ids,
 	.probe		= spi_flash_std_probe,
 	.remove		= spi_flash_std_remove,
+	.on_reset	= spi_flash_std_remove,
 	.priv_auto	= sizeof(struct spi_nor),
 	.ops		= &spi_flash_std_ops,
 	.flags		= DM_FLAG_OS_PREPARE,
-- 
2.45.0