From a90b9575f3ff71de58672295504e9ebaa8f051b4 Mon Sep 17 00:00:00 2001
From: Aaron Williams <aaron.williams@caviumnetworks.com>
Date: Tue, 12 Apr 2011 00:59:04 -0700
Subject: [PATCH] cfi_flash driver - Add delay after reset command
I ran into a problem where the reset was failing except when I enabled
debugging support. After talking with Garret Swalling at Spansion I
was told that the GL-N series of devices require a 500ns wait for the
reset to complete. The below patch adds a 1us delay after all reset
commands.
-Aaron Williams
Signed-off-by: Aaron Williams <aaron.williams@caviumnetworks.com>
Signed-off-by: Stefan Roese <sr@denx.de>
---
drivers/mtd/cfi_flash.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index aa76f6ce48..6039e1fadc 100644
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -581,6 +581,7 @@ static int flash_status_check (flash_info_t * info, flash_sect_t sector,
prompt, info->start[sector],
flash_read_long (info, sector, 0));
flash_write_cmd (info, sector, 0, info->cmd_reset);
+ udelay(1);
return ERR_TIMOUT;
}
udelay (1); /* also triggers watchdog */
@@ -628,6 +629,7 @@ static int flash_full_status_check (flash_info_t * info, flash_sect_t sector,
puts ("Vpp Low Error.\n");
}
flash_write_cmd (info, sector, 0, info->cmd_reset);
+ udelay(1);
break;
default:
break;
@@ -1491,6 +1493,7 @@ void flash_read_user_serial (flash_info_t * info, void *buffer, int offset,
flash_write_cmd (info, 0, 0, FLASH_CMD_READ_ID);
memcpy (dst, src + offset, len);
flash_write_cmd (info, 0, 0, info->cmd_reset);
+ udelay(1);
flash_unmap(info, 0, FLASH_OFFSET_USER_PROTECTION, src);
}
@@ -1506,6 +1509,7 @@ void flash_read_factory_serial (flash_info_t * info, void *buffer, int offset,
flash_write_cmd (info, 0, 0, FLASH_CMD_READ_ID);
memcpy (buffer, src + offset, len);
flash_write_cmd (info, 0, 0, info->cmd_reset);
+ udelay(1);
flash_unmap(info, 0, FLASH_OFFSET_INTEL_PROTECTION, src);
}
@@ -1537,6 +1541,7 @@ static void cfi_reverse_geometry(struct cfi_qry *qry)
static void cmdset_intel_read_jedec_ids(flash_info_t *info)
{
flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
+ udelay(1);
flash_write_cmd(info, 0, 0, FLASH_CMD_READ_ID);
udelay(1000); /* some flash are slow to respond */
info->manufacturer_id = flash_read_uchar (info,
@@ -1613,6 +1618,7 @@ static void cmdset_amd_read_jedec_ids(flash_info_t *info)
break;
}
flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
+ udelay(1);
}
static int cmdset_amd_init(flash_info_t *info, struct cfi_qry *qry)
@@ -1739,6 +1745,7 @@ void __flash_cmd_reset(flash_info_t *info)
* that AMD flash roms ignore the Intel command.
*/
flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
+ udelay(1);
flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
}
void flash_cmd_reset(flash_info_t *info)
--
2.39.5