[PATCH] spl: spl_spi: add spi_nor_remove() to soft reset flash

[Vaishnav Achath]

On probe, the SPI NOR core will put a flash in 8D mode if it
supports it. But Linux as of now expects to get the flash in
1S mode. Handing the flash to Linux in Octal DTR mode means
the kernel will fail to detect the flash.

This commit adds an option to soft reset the flash after
spl_spi_load_image() so that the flash can be reset to 1S mode
and subsequent spi-nor probe in Linux does not fail, since
spl_spi_load_image() performs spi_flash_probe() the remove is
added after completion loading images in spi_flash_probe() itself.

Tested on J721E EVM with 5.10 Linux kernel.

Linux spi-nor probe without the fix:
root at j7-evm:~# dmesg | grep spi-nor
[    4.928023] spi-nor spi0.0: unrecognized JEDEC id bytes: ff ff ff ff ff ff
[    4.934938] spi-nor: probe of spi0.0 failed with error -2

Linux spi-nor probe with the fix:
root at j7-evm:~# dmesg | grep spi-nor
[    4.904484] spi-nor spi0.0: mt35xu512aba (65536 Kbytes)

Signed-off-by: Vaishnav Achath <vaishnav.a at ti.com>
---
 common/spl/spl_spi.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/common/spl/spl_spi.c b/common/spl/spl_spi.c
index cf3f7ef4c0..113a85bec9 100644
--- a/common/spl/spl_spi.c
+++ b/common/spl/spl_spi.c
@@ -162,6 +162,11 @@ static int spl_spi_load_image(struct spl_image_info *spl_image,
 					     spl_image->size,
 					     (void *)spl_image->load_addr);
 		}
+		if (IS_ENABLED(CONFIG_SPI_FLASH_SOFT_RESET)) {
+			err = spi_nor_remove(flash);
+			if (err)
+				return err;
+		}
 	}
 
 	return err;
-- 
2.17.1