[PATCH 06/12] cfi_flash: update manufacturer id flash support

[Jean-Christophe PLAGNIOL-VILLARD]

several first banks can contain 0x7f instead of actual ID

support as done in linux

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
---
 drivers/nor/cfi_flash.c       |   18 ++++++++++++++++++
 drivers/nor/cfi_flash.h       |    3 +++
 drivers/nor/cfi_flash_amd.c   |    4 ++--
 drivers/nor/cfi_flash_intel.c |    4 ++--
 4 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/drivers/nor/cfi_flash.c b/drivers/nor/cfi_flash.c
index fb5935e..a1e0726 100644
--- a/drivers/nor/cfi_flash.c
+++ b/drivers/nor/cfi_flash.c
@@ -269,6 +269,24 @@ static ulong flash_read_long (struct flash_info *info, flash_sect_t sect, uint o
  * http://www.jedec.org/download/search/jesd68.pdf
  *
 */
+u32 jedec_read_mfr(struct flash_info *info)
+{
+	int bank = 0;
+	uchar mfr;
+
+	/* According to JEDEC "Standard Manufacturer's Identification Code"
+	 * (http://www.jedec.org/download/search/jep106W.pdf)
+	 * several first banks can contain 0x7f instead of actual ID
+	 */
+	do {
+		mfr = flash_read_uchar (info,
+				(bank << 8) | FLASH_OFFSET_MANUFACTURER_ID);
+		bank++;
+	} while (mfr == FLASH_ID_CONTINUATION);
+
+	return mfr;
+}
+
 static int flash_detect_cfi (struct flash_info *info)
 {
 	int cfi_offset;
diff --git a/drivers/nor/cfi_flash.h b/drivers/nor/cfi_flash.h
index 4094b02..877822a 100644
--- a/drivers/nor/cfi_flash.h
+++ b/drivers/nor/cfi_flash.h
@@ -107,6 +107,8 @@ extern struct cfi_cmd_set cfi_cmd_set_amd;
 #define FLASH_STATUS_R			0x01
 #define FLASH_STATUS_PROTECT		0x01
 
+#define FLASH_ID_CONTINUATION		0x7F
+
 #define AMD_CMD_RESET			0xF0
 #define AMD_CMD_WRITE			0xA0
 #define AMD_CMD_ERASE_START		0x80
@@ -211,6 +213,7 @@ static inline uchar *flash_make_addr (struct flash_info *info, flash_sect_t sect
 }
 
 uchar flash_read_uchar (struct flash_info *info, uint offset);
+u32 jedec_read_mfr(struct flash_info *info);
 
 #ifdef CONFIG_DRIVER_CFI_BANK_WIDTH_1
 #define bankwidth_is_1(info) (info->portwidth == 1)
diff --git a/drivers/nor/cfi_flash_amd.c b/drivers/nor/cfi_flash_amd.c
index c64377b..54e764d 100644
--- a/drivers/nor/cfi_flash_amd.c
+++ b/drivers/nor/cfi_flash_amd.c
@@ -42,8 +42,8 @@ static void amd_read_jedec_ids (struct flash_info *info)
 	flash_unlock_seq(info);
 	flash_write_cmd(info, 0, info->addr_unlock1, FLASH_CMD_READ_ID);
 	udelay(1000); /* some flash are slow to respond */
-	info->manufacturer_id = flash_read_uchar (info,
-					FLASH_OFFSET_MANUFACTURER_ID);
+
+	info->manufacturer_id = jedec_read_mfr(info);
 	info->device_id = flash_read_uchar (info,
 					FLASH_OFFSET_DEVICE_ID);
 	if (info->device_id == 0x7E) {
diff --git a/drivers/nor/cfi_flash_intel.c b/drivers/nor/cfi_flash_intel.c
index a71f7c4..649f83b 100644
--- a/drivers/nor/cfi_flash_intel.c
+++ b/drivers/nor/cfi_flash_intel.c
@@ -16,8 +16,8 @@ static void intel_read_jedec_ids (struct flash_info *info)
 	flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
 	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,
-					FLASH_OFFSET_MANUFACTURER_ID);
+
+	info->manufacturer_id = jedec_read_mfr(info);
 	info->device_id = flash_read_uchar (info,
 					FLASH_OFFSET_DEVICE_ID);
 	flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
-- 
1.7.1