nand: Add support for unlock.invert

NAND unlock command allows an invert bit to be set to unlock all but
the selected page range.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
[scottwood@freescale.com: updated docs and added comment about invert bit]
Signed-off-by: Scott Wood <scottwood@freescale.com>

common/cmd_nand.c

@@ -749,11 +749,18 @@ int do_nand(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
 		return 0;
 	}
 
-	if (strcmp(cmd, "unlock") == 0) {
+	if (strncmp(cmd, "unlock", 5) == 0) {
+		int allexcept = 0;
+
+		s = strchr(cmd, '.');
+
+		if (s && !strcmp(s, ".allexcept"))
+			allexcept = 1;
+
 		if (arg_off_size(argc - 2, argv + 2, &dev, &off, &size) < 0)
 			return 1;
 
-		if (!nand_unlock(&nand_info[dev], off, size)) {
+		if (!nand_unlock(&nand_info[dev], off, size, allexcept)) {
 			puts("NAND flash successfully unlocked\n");
 		} else {
 			puts("Error unlocking NAND flash, "
@@ -807,7 +814,7 @@ U_BOOT_CMD(
 	"\n"
 	"nand lock [tight] [status]\n"
 	"    bring nand to lock state or display locked pages\n"
-	"nand unlock [offset] [size] - unlock section"
+	"nand unlock[.allexcept] [offset] [size] - unlock section"
 #endif
 #ifdef CONFIG_ENV_OFFSET_OOB
 	"\n"

doc/README.nand

@@ -228,6 +228,8 @@ NAND locking command (for chips with active LOCKPRE pin)
   "nand unlock [offset] [size]"
   unlock consecutive area (can be called multiple times for different areas)
 
+  "nand unlock.allexcept [offset] [size]"
+  unlock all except specified consecutive area
 
 I have tested the code with board containing 128MiB NAND large page chips
 and 32MiB small page chips.

drivers/mtd/nand/nand_util.c

@@ -317,18 +317,20 @@ int nand_get_lock_status(struct mtd_info *mtd, loff_t offset)
  * @param start		start byte address
  * @param length	number of bytes to unlock (must be a multiple of
  *			page size nand->writesize)
+ * @param allexcept	if set, unlock everything not selected
  *
  * @return		0 on success, -1 in case of error
  */
-int nand_unlock(struct mtd_info *mtd, ulong start, ulong length)
+int nand_unlock(struct mtd_info *mtd, ulong start, ulong length, int allexcept)
 {
 	int ret = 0;
 	int chipnr;
 	int status;
 	int page;
 	struct nand_chip *chip = mtd->priv;
-	printf ("nand_unlock: start: %08x, length: %d!\n",
-		(int)start, (int)length);
+
+	debug("nand_unlock%s: start: %08x, length: %d!\n",
+		allexcept ? " (allexcept)" : "", start, length);
 
 	/* select the NAND device */
 	chipnr = (int)(start >> chip->chip_shift);
@@ -368,6 +370,15 @@ int nand_unlock(struct mtd_info *mtd, ulong start, ulong length)
 
 	/* submit ADDRESS of LAST page to unlock */
 	page += (int)(length >> chip->page_shift);
+
+	/*
+	 * Page addresses for unlocking are supposed to be block-aligned.
+	 * At least some NAND chips use the low bit to indicate that the
+	 * page range should be inverted.
+	 */
+	if (allexcept)
+		page |= 1;
+
 	chip->cmdfunc(mtd, NAND_CMD_UNLOCK2, -1, page & chip->pagemask);
 
 	/* call wait ready function */

include/nand.h

@@ -144,8 +144,8 @@ int nand_erase_opts(nand_info_t *meminfo, const nand_erase_options_t *opts);
 #define NAND_LOCK_STATUS_LOCK	0x02
 #define NAND_LOCK_STATUS_UNLOCK 0x04
 
-int nand_lock( nand_info_t *meminfo, int tight );
-int nand_unlock( nand_info_t *meminfo, ulong start, ulong length );
+int nand_lock(nand_info_t *meminfo, int tight);
+int nand_unlock(nand_info_t *meminfo, ulong start, ulong length, int allexcept);
 int nand_get_lock_status(nand_info_t *meminfo, loff_t offset);
 
 int nand_spl_load_image(uint32_t offs, unsigned int size, void *dst);