mtd: nand: add support for reading ONFI parameters from NAND device

This patch adds support for reading NAND device ONFI parameters and use
the ONFI informations to define its geometry. In case the device supports
ONFI, the onfi_version field in struct nand_chip contains the version (BCD)
and the onfi_params structure can be used by drivers to set up timings and
such. We currently only support ONFI 1.0 parameters.

Signed-off-by: Brian Norris <norris@broadcom.com>
Signed-off-by: Matthieu Castet <matthieu.castet@parrot.com>
Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 596ac84..5b26fff 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2787,14 +2787,46 @@
 }
 
 /*
+ * sanitize ONFI strings so we can safely print them
+ */
+static void sanitize_string(uint8_t *s, size_t len)
+{
+	ssize_t i;
+
+	/* null terminate */
+	s[len - 1] = 0;
+
+	/* remove non printable chars */
+	for (i = 0; i < len - 1; i++) {
+		if (s[i] < ' ' || s[i] > 127)
+			s[i] = '?';
+	}
+
+	/* remove trailing spaces */
+	strim(s);
+}
+
+static u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
+{
+	int i;
+	while (len--) {
+		crc ^= *p++ << 8;
+		for (i = 0; i < 8; i++)
+			crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
+	}
+
+	return crc;
+}
+
+/*
  * Get the flash and manufacturer id and lookup if the type is supported
  */
 static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
 						  struct nand_chip *chip,
-						  int busw, int *maf_id,
+						  int busw, int *maf_id, int *dev_id,
 						  struct nand_flash_dev *type)
 {
-	int i, dev_id, maf_idx;
+	int i, maf_idx;
 	u8 id_data[8];
 
 	/* Select the device */
@@ -2811,7 +2843,7 @@
 
 	/* Read manufacturer and device IDs */
 	*maf_id = chip->read_byte(mtd);
-	dev_id = chip->read_byte(mtd);
+	*dev_id = chip->read_byte(mtd);
 
 	/* Try again to make sure, as some systems the bus-hold or other
 	 * interface concerns can cause random data which looks like a
@@ -2821,15 +2853,13 @@
 
 	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
 
-	/* Read entire ID string */
-
-	for (i = 0; i < 8; i++)
+	for (i = 0; i < 2; i++)
 		id_data[i] = chip->read_byte(mtd);
 
-	if (id_data[0] != *maf_id || id_data[1] != dev_id) {
+	if (id_data[0] != *maf_id || id_data[1] != *dev_id) {
 		printk(KERN_INFO "%s: second ID read did not match "
 		       "%02x,%02x against %02x,%02x\n", __func__,
-		       *maf_id, dev_id, id_data[0], id_data[1]);
+		       *maf_id, *dev_id, id_data[0], id_data[1]);
 		return ERR_PTR(-ENODEV);
 	}
 
@@ -2837,9 +2867,81 @@
 		type = nand_flash_ids;
 
 	for (; type->name != NULL; type++)
-		if (dev_id == type->id)
+		if (*dev_id == type->id)
                         break;
 
+	chip->onfi_version = 0;
+	if (!type->name || !type->pagesize) {
+		/* try ONFI for unknow chip or LP */
+		chip->cmdfunc(mtd, NAND_CMD_READID, 0x20, -1);
+		if (chip->read_byte(mtd) == 'O' &&
+			chip->read_byte(mtd) == 'N' &&
+			chip->read_byte(mtd) == 'F' &&
+			chip->read_byte(mtd) == 'I') {
+
+			struct nand_onfi_params *p = &chip->onfi_params;
+			int i;
+
+			printk(KERN_INFO "ONFI flash detected\n");
+			chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
+			for (i = 0; i < 3; i++) {
+				chip->read_buf(mtd, (uint8_t *)p, sizeof(*p));
+				if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
+								le16_to_cpu(p->crc))
+				{
+					 printk(KERN_INFO "ONFI param page %d valid\n", i);
+					 break;
+				}
+			}
+
+			if (i < 3) {
+				/* check version */
+				int val = le16_to_cpu(p->revision);
+				if (val == 1 || val > (1 << 4))
+					printk(KERN_INFO "%s: unsupported ONFI version: %d\n",
+						__func__, val);
+				else {
+					if (val & (1 << 4))
+						chip->onfi_version = 22;
+					else if (val & (1 << 3))
+						chip->onfi_version = 21;
+					else if (val & (1 << 2))
+						chip->onfi_version = 20;
+					else
+						chip->onfi_version = 10;
+				}
+			}
+
+			if (chip->onfi_version) {
+				sanitize_string(p->manufacturer, sizeof(p->manufacturer));
+				sanitize_string(p->model, sizeof(p->model));
+				if (!mtd->name)
+					mtd->name = p->model;
+				mtd->writesize = le32_to_cpu(p->byte_per_page);
+				mtd->erasesize = le32_to_cpu(p->pages_per_block)*mtd->writesize;
+				mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
+				chip->chipsize = le32_to_cpu(p->blocks_per_lun) * mtd->erasesize;
+				busw = 0;
+				if (le16_to_cpu(p->features) & 1)
+					busw = NAND_BUSWIDTH_16;
+
+				chip->options &= ~NAND_CHIPOPTIONS_MSK;
+				chip->options |= (NAND_NO_READRDY |
+						NAND_NO_AUTOINCR) & NAND_CHIPOPTIONS_MSK;
+
+				goto ident_done;
+
+			}
+		}
+	}
+
+	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
+
+	/* Read entire ID string */
+
+	for (i = 0; i < 8; i++)
+		id_data[i] = chip->read_byte(mtd);
+
 	if (!type->name)
 		return ERR_PTR(-ENODEV);
 
@@ -2927,6 +3029,21 @@
 			mtd->erasesize <<= ((id_data[3] & 0x03) << 1);
 		}
 	}
+	/* Get chip options, preserve non chip based options */
+	chip->options &= ~NAND_CHIPOPTIONS_MSK;
+	chip->options |= type->options & NAND_CHIPOPTIONS_MSK;
+
+	/* Check if chip is a not a samsung device. Do not clear the
+	 * options for chips which are not having an extended id.
+	 */
+	if (*maf_id != NAND_MFR_SAMSUNG && !type->pagesize)
+		chip->options &= ~NAND_SAMSUNG_LP_OPTIONS;
+ident_done:
+
+	/*
+	 * Set chip as a default. Board drivers can override it, if necessary
+	 */
+	chip->options |= NAND_NO_AUTOINCR;
 
 	/* Try to identify manufacturer */
 	for (maf_idx = 0; nand_manuf_ids[maf_idx].id != 0x0; maf_idx++) {
@@ -2941,7 +3058,7 @@
 	if (busw != (chip->options & NAND_BUSWIDTH_16)) {
 		printk(KERN_INFO "NAND device: Manufacturer ID:"
 		       " 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id,
-		       dev_id, nand_manuf_ids[maf_idx].name, mtd->name);
+		       *dev_id, nand_manuf_ids[maf_idx].name, mtd->name);
 		printk(KERN_WARNING "NAND bus width %d instead %d bit\n",
 		       (chip->options & NAND_BUSWIDTH_16) ? 16 : 8,
 		       busw ? 16 : 8);
@@ -2966,21 +3083,6 @@
 	else
 		chip->badblockpos = NAND_SMALL_BADBLOCK_POS;
 
-	/* Get chip options, preserve non chip based options */
-	chip->options &= ~NAND_CHIPOPTIONS_MSK;
-	chip->options |= type->options & NAND_CHIPOPTIONS_MSK;
-
-	/*
-	 * Set chip as a default. Board drivers can override it, if necessary
-	 */
-	chip->options |= NAND_NO_AUTOINCR;
-
-	/* Check if chip is a not a samsung device. Do not clear the
-	 * options for chips which are not having an extended id.
-	 */
-	if (*maf_id != NAND_MFR_SAMSUNG && !type->pagesize)
-		chip->options &= ~NAND_SAMSUNG_LP_OPTIONS;
-
 	/*
 	 * Bad block marker is stored in the last page of each block
 	 * on Samsung and Hynix MLC devices; stored in first two pages
@@ -3021,9 +3123,11 @@
 	if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
 		chip->cmdfunc = nand_command_lp;
 
+	/* TODO onfi flash name */
 	printk(KERN_INFO "NAND device: Manufacturer ID:"
-	       " 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id, dev_id,
-	       nand_manuf_ids[maf_idx].name, type->name);
+		" 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id, *dev_id,
+		nand_manuf_ids[maf_idx].name,
+		chip->onfi_version ? type->name:chip->onfi_params.model);
 
 	return type;
 }
@@ -3042,7 +3146,7 @@
 int nand_scan_ident(struct mtd_info *mtd, int maxchips,
 		    struct nand_flash_dev *table)
 {
-	int i, busw, nand_maf_id;
+	int i, busw, nand_maf_id, nand_dev_id;
 	struct nand_chip *chip = mtd->priv;
 	struct nand_flash_dev *type;
 
@@ -3052,7 +3156,7 @@
 	nand_set_defaults(chip, busw);
 
 	/* Read the flash type */
-	type = nand_get_flash_type(mtd, chip, busw, &nand_maf_id, table);
+	type = nand_get_flash_type(mtd, chip, busw, &nand_maf_id, &nand_dev_id, table);
 
 	if (IS_ERR(type)) {
 		if (!(chip->options & NAND_SCAN_SILENT_NODEV))
@@ -3070,7 +3174,7 @@
 		chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
 		/* Read manufacturer and device IDs */
 		if (nand_maf_id != chip->read_byte(mtd) ||
-		    type->id != chip->read_byte(mtd))
+		    nand_dev_id != chip->read_byte(mtd))
 			break;
 	}
 	if (i > 1)