cfi_flash: add support for Spansion flash PPB sector protection

Erasing flash sectors protected with persistent protection bit (PPB)
mechanism on Spansion flash chips doesn't work. Add sector protection
status checking and sector lock and unlock commands to fix this.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Stefan Roese <sr@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>

drivers/mtd/cfi_flash.c

@@ -1447,6 +1447,47 @@ int flash_real_protect (flash_info_t * info, long sector, int prot)
 							0, ATM_CMD_UNLOCK_SECT);
 				}
 			}
+			if (info->manufacturer_id == (uchar)AMD_MANUFACT) {
+				int flag = disable_interrupts();
+				int lock_flag;
+
+				flash_unlock_seq(info, 0);
+				flash_write_cmd(info, 0, info->addr_unlock1,
+						AMD_CMD_SET_PPB_ENTRY);
+				lock_flag = flash_isset(info, sector, 0, 0x01);
+				if (prot) {
+					if (lock_flag) {
+						flash_write_cmd(info, sector, 0,
+							AMD_CMD_PPB_LOCK_BC1);
+						flash_write_cmd(info, sector, 0,
+							AMD_CMD_PPB_LOCK_BC2);
+					}
+					debug("sector %ld %slocked\n", sector,
+						lock_flag ? "" : "already ");
+				} else {
+					if (!lock_flag) {
+						debug("unlock %ld\n", sector);
+						flash_write_cmd(info, 0, 0,
+							AMD_CMD_PPB_UNLOCK_BC1);
+						flash_write_cmd(info, 0, 0,
+							AMD_CMD_PPB_UNLOCK_BC2);
+					}
+					debug("sector %ld %sunlocked\n", sector,
+						!lock_flag ? "" : "already ");
+				}
+				if (flag)
+					enable_interrupts();
+
+				if (flash_status_check(info, sector,
+						info->erase_blk_tout,
+						prot ? "protect" : "unprotect"))
+					printf("status check error\n");
+
+				flash_write_cmd(info, 0, 0,
+						AMD_CMD_SET_PPB_EXIT_BC1);
+				flash_write_cmd(info, 0, 0,
+						AMD_CMD_SET_PPB_EXIT_BC2);
+			}
 			break;
 #ifdef CONFIG_FLASH_CFI_LEGACY
 		case CFI_CMDSET_AMD_LEGACY:
@@ -1635,6 +1676,17 @@ static int cmdset_amd_init(flash_info_t *info, struct cfi_qry *qry)
 	cmdset_amd_read_jedec_ids(info);
 	flash_write_cmd(info, 0, info->cfi_offset, FLASH_CMD_CFI);
 
+#ifdef CONFIG_SYS_FLASH_PROTECTION
+	if (info->ext_addr && info->manufacturer_id == (uchar)AMD_MANUFACT) {
+		ushort spus;
+
+		/* read sector protect/unprotect scheme */
+		spus = flash_read_uchar(info, info->ext_addr + 9);
+		if (spus == 0x8)
+			info->legacy_unlock = 1;
+	}
+#endif
+
 	return 0;
 }
 

include/mtd/cfi_flash.h

@@ -60,6 +60,13 @@
 #define AMD_CMD_UNLOCK_ACK		0x55
 #define AMD_CMD_WRITE_TO_BUFFER		0x25
 #define AMD_CMD_WRITE_BUFFER_CONFIRM	0x29
+#define AMD_CMD_SET_PPB_ENTRY		0xC0
+#define AMD_CMD_SET_PPB_EXIT_BC1	0x90
+#define AMD_CMD_SET_PPB_EXIT_BC2	0x00
+#define AMD_CMD_PPB_UNLOCK_BC1		0x80
+#define AMD_CMD_PPB_UNLOCK_BC2		0x30
+#define AMD_CMD_PPB_LOCK_BC1		0xA0
+#define AMD_CMD_PPB_LOCK_BC2		0x00
 
 #define AMD_STATUS_TOGGLE		0x40
 #define AMD_STATUS_ERROR		0x20