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authorPekon Gupta <pekon@ti.com>2014-02-26 15:53:12 +0530
committerBrian Norris <computersforpeace@gmail.com>2014-03-20 02:30:27 -0700
commitf5dc06fb71ae10c4f205a08f5ef26fd90fc122fc (patch)
tree24547188b4066545021652471bcc695c8b1ecdb9 /drivers/mtd/nand
parenta4c7ca004d984306c33df6d89c76ccd232317c21 (diff)
mtd: nand: omap: ecc.calculate: refactor omap_calculate_ecc_bch for BCHx_HW ecc-scheme
OMAP NAND driver supports multiple flavours of BCH4 and BCH8 ECC algorithms. +------+------------------------------------+---------------+---------------+ | Algo | ECC scheme |ECC calculation|Error detection| +------+------------------------------------+---------------+---------------+ | |OMAP_ECC_BCH4_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W | | BCH4 |OMAP_ECC_BCH4_CODE_HW |H/W (GPMC) |H/W (ELM) | +------+------------------------------------+---------------+---------------+ | |OMAP_ECC_BCH8_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W | | BCH8 |OMAP_ECC_BCH8_CODE_HW |H/W (GPMC) |H/W (ELM) | +------+------------------------------------+---------------+---------------+ This patch refactors omap_calculate_ecc_bch() so that - separate out ecc-scheme specific code so that common-code can be reused between different implementations of same ECC algorithm. - new ecc-schemes can be added with ease in future. Tested-by: Stefan Roese <sr@denx.de> Signed-off-by: Pekon Gupta <pekon@ti.com> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Diffstat (limited to 'drivers/mtd/nand')
-rw-r--r--drivers/mtd/nand/omap2.c68
1 files changed, 35 insertions, 33 deletions
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 4b98ee52e5e..2ccd557bf77 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1219,33 +1219,25 @@ static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat,
* Support calculating of BCH4/8 ecc vectors for the page
*/
static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
- const u_char *dat, u_char *ecc_code)
+ const u_char *dat, u_char *ecc_calc)
{
struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
mtd);
+ int eccbytes = info->nand.ecc.bytes;
+ struct gpmc_nand_regs *gpmc_regs = &info->reg;
+ u8 *ecc_code;
unsigned long nsectors, bch_val1, bch_val2, bch_val3, bch_val4;
- int i, eccbchtsel;
+ int i;
nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1;
- /*
- * find BCH scheme used
- * 0 -> BCH4
- * 1 -> BCH8
- */
- eccbchtsel = ((readl(info->reg.gpmc_ecc_config) >> 12) & 0x3);
-
for (i = 0; i < nsectors; i++) {
-
- /* Read hw-computed remainder */
- bch_val1 = readl(info->reg.gpmc_bch_result0[i]);
- bch_val2 = readl(info->reg.gpmc_bch_result1[i]);
- if (eccbchtsel) {
- bch_val3 = readl(info->reg.gpmc_bch_result2[i]);
- bch_val4 = readl(info->reg.gpmc_bch_result3[i]);
- }
-
- if (eccbchtsel) {
- /* BCH8 ecc scheme */
+ ecc_code = ecc_calc;
+ switch (info->ecc_opt) {
+ case OMAP_ECC_BCH8_CODE_HW:
+ bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
+ bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
+ bch_val3 = readl(gpmc_regs->gpmc_bch_result2[i]);
+ bch_val4 = readl(gpmc_regs->gpmc_bch_result3[i]);
*ecc_code++ = (bch_val4 & 0xFF);
*ecc_code++ = ((bch_val3 >> 24) & 0xFF);
*ecc_code++ = ((bch_val3 >> 16) & 0xFF);
@@ -1259,14 +1251,10 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
*ecc_code++ = ((bch_val1 >> 16) & 0xFF);
*ecc_code++ = ((bch_val1 >> 8) & 0xFF);
*ecc_code++ = (bch_val1 & 0xFF);
- /*
- * Setting 14th byte to zero to handle
- * erased page & maintain compatibility
- * with RBL
- */
- *ecc_code++ = 0x0;
- } else {
- /* BCH4 ecc scheme */
+ break;
+ case OMAP_ECC_BCH4_CODE_HW:
+ bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
+ bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
*ecc_code++ = ((bch_val2 >> 12) & 0xFF);
*ecc_code++ = ((bch_val2 >> 4) & 0xFF);
*ecc_code++ = ((bch_val2 & 0xF) << 4) |
@@ -1275,12 +1263,26 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
*ecc_code++ = ((bch_val1 >> 12) & 0xFF);
*ecc_code++ = ((bch_val1 >> 4) & 0xFF);
*ecc_code++ = ((bch_val1 & 0xF) << 4);
- /*
- * Setting 8th byte to zero to handle
- * erased page
- */
- *ecc_code++ = 0x0;
+ break;
+ default:
+ return -EINVAL;
}
+
+ /* ECC scheme specific syndrome customizations */
+ switch (info->ecc_opt) {
+ case OMAP_ECC_BCH4_CODE_HW:
+ /* Set 8th ECC byte as 0x0 for ROM compatibility */
+ ecc_calc[eccbytes - 1] = 0x0;
+ break;
+ case OMAP_ECC_BCH8_CODE_HW:
+ /* Set 14th ECC byte as 0x0 for ROM compatibility */
+ ecc_calc[eccbytes - 1] = 0x0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ecc_calc += eccbytes;
}
return 0;