mtd: get the ECC info from the Extended Parameter Page

[karo-tx-linux.git] / drivers / mtd / nand / nand_base.c

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 42d44bb40873af12db6213ab228dcfa4c34fb54a..d8c723c185b2e7c86e0a247a79bc1c8e94082b31 100644 (file)
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2848,6 +2848,78 @@ static u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
        return crc;
 }
 
+/* Parse the Extended Parameter Page. */
+static int nand_flash_detect_ext_param_page(struct mtd_info *mtd,
+               struct nand_chip *chip, struct nand_onfi_params *p)
+{
+       struct onfi_ext_param_page *ep;
+       struct onfi_ext_section *s;
+       struct onfi_ext_ecc_info *ecc;
+       uint8_t *cursor;
+       int ret = -EINVAL;
+       int len;
+       int i;
+
+       len = le16_to_cpu(p->ext_param_page_length) * 16;
+       ep = kmalloc(len, GFP_KERNEL);
+       if (!ep) {
+               ret = -ENOMEM;
+               goto ext_out;
+       }
+
+       /* Send our own NAND_CMD_PARAM. */
+       chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
+
+       /* Use the Change Read Column command to skip the ONFI param pages. */
+       chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
+                       sizeof(*p) * p->num_of_param_pages , -1);
+
+       /* Read out the Extended Parameter Page. */
+       chip->read_buf(mtd, (uint8_t *)ep, len);
+       if ((onfi_crc16(ONFI_CRC_BASE, ((uint8_t *)ep) + 2, len - 2)
+               != le16_to_cpu(ep->crc))) {
+               pr_debug("fail in the CRC.\n");
+               goto ext_out;
+       }
+
+       /*
+        * Check the signature.
+        * Do not strictly follow the ONFI spec, maybe changed in future.
+        */
+       if (strncmp(ep->sig, "EPPS", 4)) {
+               pr_debug("The signature is invalid.\n");
+               goto ext_out;
+       }
+
+       /* find the ECC section. */
+       cursor = (uint8_t *)(ep + 1);
+       for (i = 0; i < ONFI_EXT_SECTION_MAX; i++) {
+               s = ep->sections + i;
+               if (s->type == ONFI_SECTION_TYPE_2)
+                       break;
+               cursor += s->length * 16;
+       }
+       if (i == ONFI_EXT_SECTION_MAX) {
+               pr_debug("We can not find the ECC section.\n");
+               goto ext_out;
+       }
+
+       /* get the info we want. */
+       ecc = (struct onfi_ext_ecc_info *)cursor;
+
+       if (ecc->codeword_size) {
+               chip->ecc_strength_ds = ecc->ecc_bits;
+               chip->ecc_step_ds = 1 << ecc->codeword_size;
+       }
+
+       pr_info("ONFI extended param page detected.\n");
+       return 0;
+
+ext_out:
+       kfree(ep);
+       return ret;
+}
+
 /*
  * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
  */
@@ -2916,6 +2988,21 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
        if (p->ecc_bits != 0xff) {
                chip->ecc_strength_ds = p->ecc_bits;
                chip->ecc_step_ds = 512;
+       } else if (chip->onfi_version >= 21 &&
+               (onfi_feature(chip) & ONFI_FEATURE_EXT_PARAM_PAGE)) {
+
+               /*
+                * The nand_flash_detect_ext_param_page() uses the
+                * Change Read Column command which maybe not supported
+                * by the chip->cmdfunc. So try to update the chip->cmdfunc
+                * now. We do not replace user supplied command function.
+                */
+               if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
+                       chip->cmdfunc = nand_command_lp;
+
+               /* The Extended Parameter Page is supported since ONFI 2.1. */
+               if (nand_flash_detect_ext_param_page(mtd, chip, p))
+                       pr_info("Failed to detect the extended param page.\n");
        }
 
        pr_info("ONFI flash detected\n");