Added ONDIE ECC support. Currently this ecc mode is supported for
specific micron parts with oob size 64 bytes.

Signed-off-by: Punnaiah Choudary Kalluri <punn...@xilinx.com>
---
 drivers/mtd/nand/pl353_nand.c |  131 +++++++++++++++++++++++++++++++++++++++-
 1 files changed, 127 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/pl353_nand.c b/drivers/mtd/nand/pl353_nand.c
index eca205f..4f56c7f 100644
--- a/drivers/mtd/nand/pl353_nand.c
+++ b/drivers/mtd/nand/pl353_nand.c
@@ -140,6 +140,48 @@ static struct nand_ecclayout nand_oob_64 = {
                 .length = 50} }
 };
 
+static struct nand_ecclayout ondie_nand_oob_64 = {
+       .eccbytes = 32,
+
+       .eccpos = {
+               8, 9, 10, 11, 12, 13, 14, 15,
+               24, 25, 26, 27, 28, 29, 30, 31,
+               40, 41, 42, 43, 44, 45, 46, 47,
+               56, 57, 58, 59, 60, 61, 62, 63
+       },
+
+       .oobfree = {
+               { .offset = 4, .length = 4 },
+               { .offset = 20, .length = 4 },
+               { .offset = 36, .length = 4 },
+               { .offset = 52, .length = 4 }
+       }
+};
+
+/* Generic flash bbt decriptors */
+static uint8_t bbt_pattern[] = { 'B', 'b', 't', '0' };
+static uint8_t mirror_pattern[] = { '1', 't', 'b', 'B' };
+
+static struct nand_bbt_descr bbt_main_descr = {
+       .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
+               | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
+       .offs = 4,
+       .len = 4,
+       .veroffs = 20,
+       .maxblocks = 4,
+       .pattern = bbt_pattern
+};
+
+static struct nand_bbt_descr bbt_mirror_descr = {
+       .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
+               | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
+       .offs = 4,
+       .len = 4,
+       .veroffs = 20,
+       .maxblocks = 4,
+       .pattern = mirror_pattern
+};
+
 /**
  * pl353_nand_calculate_hwecc - Calculate Hardware ECC
  * @mtd:       Pointer to the mtd_info structure
@@ -816,15 +858,74 @@ static int pl353_nand_device_ready(struct mtd_info *mtd)
 }
 
 /**
+ * pl353_nand_detect_ondie_ecc - Get the flash ondie ecc state
+ * @mtd:       Pointer to the mtd_info structure
+ *
+ * This function enables the ondie ecc for the Micron ondie ecc capable devices
+ *
+ * Return:     1 on detect, 0 if fail to detect
+ */
+static int pl353_nand_detect_ondie_ecc(struct mtd_info *mtd)
+{
+       struct nand_chip *nand_chip = mtd->priv;
+       u8 maf_id, dev_id, i, get_feature;
+       u8 set_feature[4] = { 0x08, 0x00, 0x00, 0x00 };
+
+       /* Check if On-Die ECC flash */
+       nand_chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+       nand_chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
+
+       /* Read manufacturer and device IDs */
+       maf_id = readb(nand_chip->IO_ADDR_R);
+       dev_id = readb(nand_chip->IO_ADDR_R);
+
+       if ((maf_id == NAND_MFR_MICRON) &&
+           ((dev_id == 0xf1) || (dev_id == 0xa1) ||
+            (dev_id == 0xb1) || (dev_id == 0xaa) ||
+            (dev_id == 0xba) || (dev_id == 0xda) ||
+            (dev_id == 0xca) || (dev_id == 0xac) ||
+            (dev_id == 0xbc) || (dev_id == 0xdc) ||
+            (dev_id == 0xcc) || (dev_id == 0xa3) ||
+            (dev_id == 0xb3) ||
+            (dev_id == 0xd3) || (dev_id == 0xc3))) {
+
+               nand_chip->cmdfunc(mtd, NAND_CMD_GET_FEATURES,
+                                  ONDIE_ECC_FEATURE_ADDR, -1);
+               get_feature = readb(nand_chip->IO_ADDR_R);
+
+               if (get_feature & 0x08) {
+                       return 1;
+               } else {
+                       nand_chip->cmdfunc(mtd, NAND_CMD_SET_FEATURES,
+                                          ONDIE_ECC_FEATURE_ADDR, -1);
+                       for (i = 0; i < 4; i++)
+                               writeb(set_feature[i], nand_chip->IO_ADDR_W);
+
+                       ndelay(1000);
+
+                       nand_chip->cmdfunc(mtd, NAND_CMD_GET_FEATURES,
+                                          ONDIE_ECC_FEATURE_ADDR, -1);
+                       get_feature = readb(nand_chip->IO_ADDR_R);
+
+                       if (get_feature & 0x08)
+                               return 1;
+               }
+       }
+
+       return 0;
+}
+
+/**
  * pl353_nand_ecc_init - Initialize the ecc information as per the ecc mode
  * @mtd:       Pointer to the mtd_info structure
+ * @ondie_ecc_state:   ondie ecc status
  *
  * This function initializes the ecc block and functional pointers as per the
  * ecc mode
  *
  * Return:     Zero on success and error on failure.
  */
-static int pl353_nand_ecc_init(struct mtd_info *mtd)
+static int pl353_nand_ecc_init(struct mtd_info *mtd, int ondie_ecc_state)
 {
        struct nand_chip *nand_chip = mtd->priv;
        struct pl353_nand_info *xnand =
@@ -838,12 +939,28 @@ static int pl353_nand_ecc_init(struct mtd_info *mtd)
 
        switch (xnand->ecc_mode) {
        case NAND_ECC_HW:
-               if (mtd->writesize > 2048) {
+               if ((mtd->writesize > 2048) || ((ondie_ecc_state) &&
+                                               (mtd->oobsize != 64))) {
                        pr_warn("hardware ECC not possible\n");
                        return -ENOTSUPP;
                }
 
                nand_chip->ecc.mode = NAND_ECC_HW;
+               if (ondie_ecc_state) {
+                       /* Bypass the controller ECC block */
+                       pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_BYPASS);
+                       nand_chip->ecc.bytes = 0;
+                       nand_chip->ecc.layout = &ondie_nand_oob_64;
+                       nand_chip->ecc.read_page = pl353_nand_read_page_raw;
+                       nand_chip->ecc.write_page = pl353_nand_write_page_raw;
+                       nand_chip->ecc.size = mtd->writesize;
+                       /*
+                        * On-Die ECC spare bytes offset 8 is used for ECC codes
+                        * Use the BBT pattern descriptors
+                        */
+                       nand_chip->bbt_td = &bbt_main_descr;
+                       nand_chip->bbt_md = &bbt_mirror_descr;
+               } else {
                nand_chip->ecc.calculate = pl353_nand_calculate_hwecc;
                nand_chip->ecc.correct = pl353_nand_correct_data;
                nand_chip->ecc.hwctl = NULL;
@@ -852,13 +969,17 @@ static int pl353_nand_ecc_init(struct mtd_info *mtd)
                nand_chip->ecc.write_page = pl353_nand_write_page_hwecc;
                pl353_smc_set_ecc_pg_size(mtd->writesize);
                pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_APB);
-               /* Hardware ECC generates 3 bytes ECC code for each 512 bytes */
+                       /*
+                        * Hardware ECC generates 3 bytes ECC code for each
+                        * 512 bytes
+                        */
                nand_chip->ecc.bytes = 3;
 
                if (mtd->oobsize == 16)
                        nand_chip->ecc.layout = &nand_oob_16;
                else
                        nand_chip->ecc.layout = &nand_oob_64;
+               }
 
                break;
        case NAND_ECC_SOFT:
@@ -900,6 +1021,7 @@ static int pl353_nand_probe(struct platform_device *pdev)
        struct nand_chip *nand_chip;
        struct resource *res;
        struct mtd_part_parser_data ppdata;
+       int ondie_ecc_state;
 
        xnand = devm_kzalloc(&pdev->dev, sizeof(*xnand), GFP_KERNEL);
        if (!xnand)
@@ -942,6 +1064,7 @@ static int pl353_nand_probe(struct platform_device *pdev)
 
        platform_set_drvdata(pdev, xnand);
 
+       ondie_ecc_state = pl353_nand_detect_ondie_ecc(mtd);
        /* first scan to find the device and get the page size */
        if (nand_scan_ident(mtd, 1, NULL)) {
                dev_err(&pdev->dev, "nand_scan_ident for NAND failed\n");
@@ -952,7 +1075,7 @@ static int pl353_nand_probe(struct platform_device *pdev)
        if (xnand->ecc_mode < 0)
                xnand->ecc_mode = NAND_ECC_HW;
 
-       if (pl353_nand_ecc_init(mtd))
+       if (pl353_nand_ecc_init(mtd, ondie_ecc_state))
                return -ENOTSUPP;
 
        if (nand_chip->options & NAND_BUSWIDTH_16)
-- 
1.7.4


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