mtd/cfi: add support for SST 4KB sector granularity

Add support for SST 4KB sector granularity.

Many recent SST flashes, i.e. SST39VF3201B and similar of this family
are declared CFI-conformant from SST. They support CFI query, but implement
2 different sector sizes in the same memory: a 64KB sector (they call it
"block", std AMD erase cmd=0x30), and a 4KB sector (they call it "sector",
erase cmd=0x50). Also, CFI query on these chips, reading from address 0x2dh
of cfi query struct, detects a number of secotrs for the 4KB granularity
(flinfo shows it).

For all other aspects, they are CFI compliant, so, as Linux do, i think
it's a good idea to handle these chips in the CFI driver, with a fixup
to allow 4KB granularity, as should be expected, instead of 64KB.

Signed-off-by: Angelo Dureghello <sysamfw@gmail.com>
Signed-off-by: Stefan Rose <sr@denx.de>

diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index b2dfc53..c8099db 100644 (file)
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -1128,7 +1128,7 @@ int flash_erase (flash_info_t * info, int s_first, int s_last)
                                                AMD_CMD_ERASE_START);
                                flash_unlock_seq (info, sect);
                                flash_write_cmd (info, sect, 0,
-                                                AMD_CMD_ERASE_SECTOR);
+                                                info->cmd_erase_sector);
                                break;
 #ifdef CONFIG_FLASH_CFI_LEGACY
                        case CFI_CMDSET_AMD_LEGACY:
@@ -1733,6 +1733,7 @@ static void cmdset_amd_read_jedec_ids(flash_info_t *info)
 static int cmdset_amd_init(flash_info_t *info, struct cfi_qry *qry)
 {
        info->cmd_reset = AMD_CMD_RESET;
+       info->cmd_erase_sector = AMD_CMD_ERASE_SECTOR;
 
        cmdset_amd_read_jedec_ids(info);
        flash_write_cmd(info, 0, info->cfi_offset, FLASH_CMD_CFI);
@@ -2003,6 +2004,25 @@ static void flash_fixup_stm(flash_info_t *info, struct cfi_qry *qry)
        }
 }
 
+static void flash_fixup_sst(flash_info_t *info, struct cfi_qry *qry)
+{
+       /*
+        * SST, for many recent nor parallel flashes, says they are
+        * CFI-conformant. This is not true, since qry struct.
+        * reports a std. AMD command set (0x0002), while SST allows to
+        * erase two different sector sizes for the same memory.
+        * 64KB sector (SST call it block)  needs 0x30 to be erased.
+        * 4KB  sector (SST call it sector) needs 0x50 to be erased.
+        * Since CFI query detect the 4KB number of sectors, users expects
+        * a sector granularity of 4KB, and it is here set.
+        */
+       if (info->device_id == 0x5D23 || /* SST39VF3201B */
+           info->device_id == 0x5C23) { /* SST39VF3202B */
+               /* set sector granularity to 4KB */
+               info->cmd_erase_sector=0x50;
+       }
+}
+
 /*
  * The following code cannot be run from FLASH!
  *
@@ -2081,6 +2101,9 @@ ulong flash_get_size (phys_addr_t base, int banknum)
                case 0x0020:
                        flash_fixup_stm(info, &qry);
                        break;
+               case 0x00bf: /* SST */
+                       flash_fixup_sst(info, &qry);
+                       break;
                }
 
                debug ("manufacturer is %d\n", info->vendor);

diff --git a/include/flash.h b/include/flash.h
index 7db599e..c7acc97 100644 (file)
--- a/include/flash.h
+++ b/include/flash.h
@@ -44,6 +44,7 @@ typedef struct {
        ulong   buffer_write_tout;      /* maximum buffer write timeout         */
        ushort  vendor;                 /* the primary vendor id                */
        ushort  cmd_reset;              /* vendor specific reset command        */
+       uchar   cmd_erase_sector;       /* vendor specific erase sect. command  */
        ushort  interface;              /* used for x8/x16 adjustments          */
        ushort  legacy_unlock;          /* support Intel legacy (un)locking     */
        ushort  manufacturer_id;        /* manufacturer id                      */