+#ifdef CONFIG_SYS_NAND_ONFI_DETECTION
+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;
+}
+
+/*
+ * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise
+ */
+static int nand_flash_detect_onfi(struct mtd_info *mtd,
+ struct nand_chip *chip,
+ int *busw)
+{
+ struct nand_onfi_params *p = &chip->onfi_params;
+ int i;
+ int val;
+
+ 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')
+ return 0;
+
+ 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)
+ return 0;
+
+ /* check version */
+ val = le16_to_cpu(p->revision);
+ if (val == 1 || val > (1 << 4)) {
+ printk(KERN_INFO "%s: unsupported ONFI "
+ "version: %d\n", __func__, val);
+ return 0;
+ }
+
+ 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 (!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;
+
+ return 1;
+}
+#else
+static inline int nand_flash_detect_onfi(struct mtd_info *mtd,
+ struct nand_chip *chip,
+ int *busw)
+{
+ return 0;
+}
+#endif
+
+static void nand_flash_detect_non_onfi(struct mtd_info *mtd,
+ struct nand_chip *chip,
+ const struct nand_flash_dev *type,
+ int *busw)
+{
+ /* Newer devices have all the information in additional id bytes */
+ if (!type->pagesize) {
+ int extid;
+ /* The 3rd id byte holds MLC / multichip data */
+ chip->cellinfo = chip->read_byte(mtd);
+ /* The 4th id byte is the important one */
+ extid = chip->read_byte(mtd);
+ /* Calc pagesize */
+ mtd->writesize = 1024 << (extid & 0x3);
+ extid >>= 2;
+ /* Calc oobsize */
+ mtd->oobsize = (8 << (extid & 0x01)) * (mtd->writesize >> 9);
+ extid >>= 2;
+ /* Calc blocksize. Blocksize is multiples of 64KiB */
+ mtd->erasesize = (64 * 1024) << (extid & 0x03);
+ extid >>= 2;
+ /* Get buswidth information */
+ *busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0;
+
+ } else {
+ /*
+ * Old devices have chip data hardcoded in the device id table
+ */
+ mtd->erasesize = type->erasesize;
+ mtd->writesize = type->pagesize;
+ mtd->oobsize = mtd->writesize / 32;
+ *busw = type->options & NAND_BUSWIDTH_16;
+ }
+}
+