mtd: bcm47xxpart: alternative MAGIC for board_data partition

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=f0501e81fbaa51cfc8c28c60bc3fc7965fde94f4
Commit:     f0501e81fbaa51cfc8c28c60bc3fc7965fde94f4
Parent:     4f8aaf72287578c846ed7ac8c6114aacbf416e45
Author:     Rafał Miłecki <zajec5 at gmail.com>
AuthorDate: Sat Dec 21 19:39:12 2013 +0100
Committer:  Brian Norris <computersforpeace at gmail.com>
CommitDate: Tue Jan 7 10:07:37 2014 -0800

    mtd: bcm47xxpart: alternative MAGIC for board_data partition
    
    Some devices (like WNDR3700v3) have board_data without MPFR magic, some
    extra header or extra NVRAM around 0x100. In such case we have to look
    for another magic which is BD 0B 0D BD (BD probably stands for Board
    Data). It's located "far far away", so instead of extending buffer add
    another mtd_read.
    
    Signed-off-by: Rafał Miłecki <zajec5 at gmail.com>
    Signed-off-by: Brian Norris <computersforpeace at gmail.com>
---
 drivers/mtd/bcm47xxpart.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/mtd/bcm47xxpart.c b/drivers/mtd/bcm47xxpart.c
index 877c17c..de1eb92 100644
--- a/drivers/mtd/bcm47xxpart.c
+++ b/drivers/mtd/bcm47xxpart.c
@@ -27,6 +27,7 @@
 
 /* Magics */
 #define BOARD_DATA_MAGIC		0x5246504D	/* MPFR */
+#define BOARD_DATA_MAGIC2		0xBD0D0BBD
 #define CFE_MAGIC			0x43464531	/* 1EFC */
 #define FACTORY_MAGIC			0x59544346	/* FCTY */
 #define POT_MAGIC1			0x54544f50	/* POTT */
@@ -192,6 +193,21 @@ static int bcm47xxpart_parse(struct mtd_info *master,
 					     offset, 0);
 			continue;
 		}
+
+		/* Read middle of the block */
+		if (mtd_read(master, offset + 0x8000, 0x4,
+			     &bytes_read, (uint8_t *)buf) < 0) {
+			pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
+			       offset);
+			continue;
+		}
+
+		/* Some devices (ex. WNDR3700v3) don't have a standard 'MPFR' */
+		if (buf[0x000 / 4] == BOARD_DATA_MAGIC2) {
+			bcm47xxpart_add_part(&parts[curr_part++], "board_data",
+					     offset, MTD_WRITEABLE);
+			continue;
+		}
 	}
 
 	/* Look for NVRAM at the end of the last block. */