mtd: nand: omap: handle gpmc bch[48]

gpmc-nand bch registers are now available in driver,
make use of it to handle bch[48] instead of relying
on gpmc exported functions.

And so nand driver no longer needs gpmc header, remove it.

Signed-off-by: Afzal Mohammed <afzal@ti.com>

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index f0a1b1d..3282b15 100644 (file)
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -28,7 +28,6 @@
 #endif
 
 #include <plat/dma.h>
-#include <plat/gpmc.h>
 #include <linux/platform_data/mtd-nand-omap2.h>
 
 #define        DRIVER_NAME     "omap2-nand"
@@ -106,6 +105,7 @@
 #define        CS_MASK                         0x7
 #define        ENABLE_PREFETCH                 (0x1 << 7)
 #define        DMA_MPU_MODE_SHIFT              2
+#define        ECCSIZE0_SHIFT                  12
 #define        ECCSIZE1_SHIFT                  22
 #define        ECC1RESULTSIZE                  0x1
 #define        ECCCLEAR                        0x100
@@ -1034,19 +1034,45 @@ static int omap_dev_ready(struct mtd_info *mtd)
 static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode)
 {
        int nerrors;
-       unsigned int dev_width;
+       unsigned int dev_width, nsectors;
        struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
                                                   mtd);
        struct nand_chip *chip = mtd->priv;
+       u32 val;
 
        nerrors = (info->nand.ecc.bytes == 13) ? 8 : 4;
        dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0;
+       nsectors = 1;
        /*
         * Program GPMC to perform correction on one 512-byte sector at a time.
         * Using 4 sectors at a time (i.e. ecc.size = 2048) is also possible and
         * gives a slight (5%) performance gain (but requires additional code).
         */
-       (void)gpmc_enable_hwecc_bch(info->gpmc_cs, mode, dev_width, 1, nerrors);
+
+       writel(ECC1, info->reg.gpmc_ecc_control);
+
+       /*
+        * When using BCH, sector size is hardcoded to 512 bytes.
+        * Here we are using wrapping mode 6 both for reading and writing, with:
+        *  size0 = 0  (no additional protected byte in spare area)
+        *  size1 = 32 (skip 32 nibbles = 16 bytes per sector in spare area)
+        */
+       val = (32 << ECCSIZE1_SHIFT) | (0 << ECCSIZE0_SHIFT);
+       writel(val, info->reg.gpmc_ecc_size_config);
+
+       /* BCH configuration */
+       val = ((1                        << 16) | /* enable BCH */
+              (((nerrors == 8) ? 1 : 0) << 12) | /* 8 or 4 bits */
+              (0x06                     <<  8) | /* wrap mode = 6 */
+              (dev_width                <<  7) | /* bus width */
+              (((nsectors-1) & 0x7)     <<  4) | /* number of sectors */
+              (info->gpmc_cs            <<  1) | /* ECC CS */
+              (0x1));                            /* enable ECC */
+
+       writel(val, info->reg.gpmc_ecc_config);
+
+       /* clear ecc and enable bits */
+       writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control);
 }
 
 /**
@@ -1060,7 +1086,32 @@ static int omap3_calculate_ecc_bch4(struct mtd_info *mtd, const u_char *dat,
 {
        struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
                                                   mtd);
-       return gpmc_calculate_ecc_bch4(info->gpmc_cs, dat, ecc_code);
+       unsigned long nsectors, val1, val2;
+       int i;
+
+       nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1;
+
+       for (i = 0; i < nsectors; i++) {
+
+               /* Read hw-computed remainder */
+               val1 = readl(info->reg.gpmc_bch_result0[i]);
+               val2 = readl(info->reg.gpmc_bch_result1[i]);
+
+               /*
+                * Add constant polynomial to remainder, in order to get an ecc
+                * sequence of 0xFFs for a buffer filled with 0xFFs; and
+                * left-justify the resulting polynomial.
+                */
+               *ecc_code++ = 0x28 ^ ((val2 >> 12) & 0xFF);
+               *ecc_code++ = 0x13 ^ ((val2 >>  4) & 0xFF);
+               *ecc_code++ = 0xcc ^ (((val2 & 0xF) << 4)|((val1 >> 28) & 0xF));
+               *ecc_code++ = 0x39 ^ ((val1 >> 20) & 0xFF);
+               *ecc_code++ = 0x96 ^ ((val1 >> 12) & 0xFF);
+               *ecc_code++ = 0xac ^ ((val1 >> 4) & 0xFF);
+               *ecc_code++ = 0x7f ^ ((val1 & 0xF) << 4);
+       }
+
+       return 0;
 }
 
 /**
@@ -1074,7 +1125,39 @@ static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat,
 {
        struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
                                                   mtd);
-       return gpmc_calculate_ecc_bch8(info->gpmc_cs, dat, ecc_code);
+       unsigned long nsectors, val1, val2, val3, val4;
+       int i;
+
+       nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1;
+
+       for (i = 0; i < nsectors; i++) {
+
+               /* Read hw-computed remainder */
+               val1 = readl(info->reg.gpmc_bch_result0[i]);
+               val2 = readl(info->reg.gpmc_bch_result1[i]);
+               val3 = readl(info->reg.gpmc_bch_result2[i]);
+               val4 = readl(info->reg.gpmc_bch_result3[i]);
+
+               /*
+                * Add constant polynomial to remainder, in order to get an ecc
+                * sequence of 0xFFs for a buffer filled with 0xFFs.
+                */
+               *ecc_code++ = 0xef ^ (val4 & 0xFF);
+               *ecc_code++ = 0x51 ^ ((val3 >> 24) & 0xFF);
+               *ecc_code++ = 0x2e ^ ((val3 >> 16) & 0xFF);
+               *ecc_code++ = 0x09 ^ ((val3 >> 8) & 0xFF);
+               *ecc_code++ = 0xed ^ (val3 & 0xFF);
+               *ecc_code++ = 0x93 ^ ((val2 >> 24) & 0xFF);
+               *ecc_code++ = 0x9a ^ ((val2 >> 16) & 0xFF);
+               *ecc_code++ = 0xc2 ^ ((val2 >> 8) & 0xFF);
+               *ecc_code++ = 0x97 ^ (val2 & 0xFF);
+               *ecc_code++ = 0x79 ^ ((val1 >> 24) & 0xFF);
+               *ecc_code++ = 0xe5 ^ ((val1 >> 16) & 0xFF);
+               *ecc_code++ = 0x24 ^ ((val1 >> 8) & 0xFF);
+               *ecc_code++ = 0xb5 ^ (val1 & 0xFF);
+       }
+
+       return 0;
 }
 
 /**
@@ -1130,7 +1213,7 @@ static void omap3_free_bch(struct mtd_info *mtd)
  */
 static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt)
 {
-       int ret, max_errors;
+       int max_errors;
        struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
                                                   mtd);
 #ifdef CONFIG_MTD_NAND_OMAP_BCH8
@@ -1147,11 +1230,6 @@ static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt)
                goto fail;
        }
 
-       /* initialize GPMC BCH engine */
-       ret = gpmc_init_hwecc_bch(info->gpmc_cs, 1, max_errors);
-       if (ret)
-               goto fail;
-
        /* software bch library is only used to detect and locate errors */
        info->bch = init_bch(13, max_errors, 0x201b /* hw polynomial */);
        if (!info->bch)