mtd: cfi_flash: Write buffer size adjustment for M29EW Numonyx devices
This patch addjusted the write buffer size for M29EW devices those
are operated in 8-bit mode.
The M29EW devices seem to report the CFI information wrong when
it's in 8 bit mode.
There's an app note from Numonyx on this issue and there's a patch
in the open source as well for Linux, but it doesn't seem to be in mainline.
Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
Tested-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index 6b9fc1a..328c76d 100644
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -2053,6 +2053,26 @@
}
}
+static void flash_fixup_num(flash_info_t *info, struct cfi_qry *qry)
+{
+ /*
+ * The M29EW devices seem to report the CFI information wrong
+ * when it's in 8 bit mode.
+ * There's an app note from Numonyx on this issue.
+ * So adjust the buffer size for M29EW while operating in 8-bit mode
+ */
+ if (((qry->max_buf_write_size) > 0x8) &&
+ (info->device_id == 0x7E) &&
+ (info->device_id2 == 0x2201 ||
+ info->device_id2 == 0x2301 ||
+ info->device_id2 == 0x2801 ||
+ info->device_id2 == 0x4801)) {
+ debug("Adjusted buffer size on Numonyx flash"
+ " M29EW family in 8 bit mode\n");
+ qry->max_buf_write_size = 0x8;
+ }
+}
+
/*
* The following code cannot be run from FLASH!
*
@@ -2135,6 +2155,9 @@
case 0x00bf: /* SST */
flash_fixup_sst(info, &qry);
break;
+ case 0x0089: /* Numonyx */
+ flash_fixup_num(info, &qry);
+ break;
}
debug ("manufacturer is %d\n", info->vendor);