Signed-off-by: Bo Shen <voice.s...@atmel.com>
---
drivers/mtd/nand/atmel_nand.c | 121 ++++++++++++++++++++++++++++++++++++++++--
1 file changed, 117 insertions(+), 4 deletions(-)
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 1e7c6c6..fa4fac2 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -766,12 +766,105 @@ static void atmel_pmecc_core_init(struct mtd_info *mtd)
pmecc_writel(host->ecc, CTRL, PMECC_CTRL_ENABLE);
}
+static uint16_t *pmecc_galois_table;
+static int pmecc_build_galois_table(unsigned int mm, int16_t *index_of,
+ int16_t *alpha_to)
+{
+ unsigned int i, mask, nn;
+ unsigned int p[15];
+
+ nn = (1 << mm) - 1;
+ /* set default value */
+ for (i = 1; i < mm; i++)
+ p[i] = 0;
+
+ /* 1 + X^mm */
+ p[0] = 1;
+ p[mm] = 1;
+
+ /* others */
+ switch (mm) {
+ case 3:
+ case 4:
+ case 6:
+ case 15:
+ p[1] = 1;
+ break;
+ case 5:
+ case 11:
+ p[2] = 1;
+ break;
+ case 7:
+ case 10:
+ p[3] = 1;
+ break;
+ case 8:
+ p[2] = p[3] = p[4] = 1;
+ break;
+ case 9:
+ p[4] = 1;
+ break;
+ case 12:
+ p[1] = p[4] = p[6] = 1;
+ break;
+ case 13:
+ p[1] = p[3] = p[4] = 1;
+ break;
+ case 14:
+ p[1] = p[6] = p[10] = 1;
+ break;
+ default:
+ /* Error */
+ return -EINVAL;
+ }
+
+ /* Build alpha ^ mm it will help to generate the field (primitiv) */
+ alpha_to[mm] = 0;
+ for (i = 0; i < mm; i++)
+ if (p[i])
+ alpha_to[mm] |= 1 << i;
+
+ /*
+ * Then build elements from 0 to mm - 1. As degree is less than mm
+ * so it is just a logical shift.
+ */
+ mask = 1;
+ for (i = 0; i < mm; i++) {
+ alpha_to[i] = mask;
+ index_of[alpha_to[i]] = i;
+ mask <<= 1;
+ }
+
+ index_of[alpha_to[mm]] = mm;
+
+ /* use a mask to select the MSB bit of the LFSR */
+ mask >>= 1;
+
+ /* then finish the building */
+ for (i = mm + 1; i <= nn; i++) {
+ /* check if the msb bit of the lfsr is set */
+ if (alpha_to[i - 1] & mask)
+ alpha_to[i] = alpha_to[mm] ^
+ ((alpha_to[i - 1] ^ mask) << 1);
+ else
+ alpha_to[i] = alpha_to[i - 1] << 1;
+
+ index_of[alpha_to[i]] = i % nn;
+ }
+
+ /* index of 0 is undefined in a multiplicative field */
+ index_of[0] = -1;
+
+ return 0;
+}
+
static int __init atmel_pmecc_nand_init_params(struct device_d *dev,
struct atmel_nand_host *host)
{
struct mtd_info *mtd = &host->mtd;
struct nand_chip *nand_chip = &host->nand_chip;
int cap, sector_size, err_no;
+ int ret;
cap = host->board->pmecc_corr_cap;
sector_size = host->board->pmecc_sector_size;
@@ -785,14 +878,34 @@ static int __init atmel_pmecc_nand_init_params(struct
device_d *dev,
}
host->pmerrloc_base = dev_request_mem_region(dev, 2);
- host->pmecc_rom_base = dev_request_mem_region(dev, 3);
-
- if (!host->pmerrloc_base || !host->pmecc_rom_base) {
+ if (!host->pmerrloc_base) {
dev_err(host->dev,
- "Can not get I/O resource for PMECC ERRLOC controller
or ROM!\n");
+ "Can not get I/O resource for PMECC ERRLOC
controller!\n");
return -EIO;
}
+ host->pmecc_rom_base = dev_request_mem_region(dev, 3);
+ if (!host->pmecc_rom_base) {
+ /* Set pmecc_rom_base as the begin of gf table */
+ int size = sector_size == 512 ? 0x2000 : 0x4000;
+ pmecc_galois_table = xzalloc(2 * size * sizeof(uint16_t));
+ if (!pmecc_galois_table)
+ return -ENOMEM;
+ host->pmecc_rom_base = pmecc_galois_table;
+ ret = pmecc_build_galois_table((sector_size == 512) ?
+ PMECC_GF_DIMENSION_13 :
+ PMECC_GF_DIMENSION_14,
+ host->pmecc_rom_base,
+ host->pmecc_rom_base + (size *
sizeof(int16_t)));
+ if (ret) {
+ dev_err(host->dev,
+ "Can not get I/O resource for ROM!\n");
+ return -EIO;
+ }
+
+ host->board->pmecc_lookup_table_offset = 0;
+ }
+
/* ECC is calculated for the whole page (1 step) */
nand_chip->ecc.size = mtd->writesize;
--
2.1.0.24.g4109c28
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