[PATCH v2 6/7] mtd: cfi_cmdset_0002: add CFI detection for SST 39VF{16, 32}xx chips

[Guillaume LECERF]

SST 39VF{16,32}xx chips use the 0x0701 command set, fully compatible
with the AMD one. This patch adds support for detecting them in CFI
mode.

Based on a patch by Peter Turczaki [1].

[1] http://www.mail-archive.com/uclinux-dev@uclinux.org/msg05737.html

Signed-off-by: Guillaume LECERF <glecerf at gmail.com>
---
 drivers/mtd/chips/cfi_cmdset_0002.c |   41 +++++++++++++++++++++++++++++++++++
 drivers/mtd/chips/gen_probe.c       |    1 +
 2 files changed, 42 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index de1b4ba..e3e4a94 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -256,6 +256,36 @@ static void fixup_use_atmel_lock(struct mtd_info *mtd, void *param)
 	mtd->flags |= MTD_POWERUP_LOCK;
 }
 
+/** While reporting a mostly-correct CFI-Information block
+  * the eraseblock-region information is severely damaged in SST
+  * parts at least those of the 39VF{16,32,64}xxB series.
+  **/
+static void fixup_old_sst_eraseregion(struct mtd_info *mtd)
+{
+	struct map_info *map = mtd->priv;
+	struct cfi_private *cfi = map->fldrv_priv;
+
+	/** Although the part claims to have two eraseblock-regions
+	  * these refer to the same region within the flash-array.
+	  * Because a really CFI-Compliant part may only return
+	  * one eraseblock-length per physical memory region
+	  * we pretend the part said it had just one region ;)
+	  **/
+	cfi->cfiq->NumEraseRegions = 1;
+	cfi->cfiq->EraseRegionInfo[0] = cfi->cfiq->EraseRegionInfo[1];
+}
+
+static void fixup_sst39vf(struct mtd_info *mtd, void *param)
+{
+	struct map_info *map = mtd->priv;
+	struct cfi_private *cfi = map->fldrv_priv;
+
+	fixup_old_sst_eraseregion(mtd);
+
+	cfi->addr_unlock1 = 0x5555;
+	cfi->addr_unlock2 = 0x2AAA;
+}
+
 static void fixup_s29gl064n_sectors(struct mtd_info *mtd, void *param)
 {
 	struct map_info *map = mtd->priv;
@@ -278,6 +308,16 @@ static void fixup_s29gl032n_sectors(struct mtd_info *mtd, void *param)
 	}
 }
 
+/* Used to fix CFI-Tables of chips without Extended Query Tables
+ */
+static struct cfi_fixup cfi_nopri_fixup_table[] = {
+	{ CFI_MFR_SST, 0x234A, fixup_sst39vf, NULL, }, // SST39VF1602
+	{ CFI_MFR_SST, 0x234B, fixup_sst39vf, NULL, }, // SST39VF1601
+	{ CFI_MFR_SST, 0x235A, fixup_sst39vf, NULL, }, // SST39VF3202
+	{ CFI_MFR_SST, 0x235B, fixup_sst39vf, NULL, }, // SST39VF3201
+	{ 0, 0, NULL, NULL }
+};
+
 static struct cfi_fixup cfi_fixup_table[] = {
 	{ CFI_MFR_ATMEL, CFI_ID_ANY, fixup_convert_atmel_pri, NULL },
 #ifdef AMD_BOOTLOC_BUG
@@ -408,6 +448,7 @@ struct mtd_info *cfi_cmdset_0002(struct map_info *map, int primary)
 			cfi->addr_unlock1 = 0x555;
 			cfi->addr_unlock2 = 0x2aa;
 		}
+		cfi_fixup(mtd, cfi_nopri_fixup_table);
 
 		if (!cfi->addr_unlock1 || !cfi->addr_unlock2) {
 			kfree(mtd);
diff --git a/drivers/mtd/chips/gen_probe.c b/drivers/mtd/chips/gen_probe.c
index 991c457..599c259 100644
--- a/drivers/mtd/chips/gen_probe.c
+++ b/drivers/mtd/chips/gen_probe.c
@@ -249,6 +249,7 @@ static struct mtd_info *check_cmd_set(struct map_info *map, int primary)
 #endif
 #ifdef CONFIG_MTD_CFI_AMDSTD
 	case P_ID_AMD_STD:
+	case P_ID_SST_OLD:
 		return cfi_cmdset_0002(map, primary);
 #endif
 #ifdef CONFIG_MTD_CFI_STAA