[PATCH v1 4/5] mtd: atmel_nand: Support 32-bit ECC strength

Romain Izard
2016-01-13T16:35:16Z

As the SAMA5D2 controller supports the 32-bit ECC strength, accept it
as a valid setting when required by the device tree or the NAND
parameter page.

Then configure the controller to do use this new setting.

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
---
.../devicetree/bindings/mtd/atmel-nand.txt | 3 ++-
drivers/mtd/nand/atmel_nand.c | 23 ++++++++++++++++++----
drivers/mtd/nand/atmel_nand_ecc.h | 1 +
3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
index 90887b430f03..ef0db8e2a0fd 100644
--- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
@@ -27,7 +27,8 @@ Optional properties:
- atmel,has-pmecc : boolean to enable Programmable Multibit ECC hardware.
Supported by AT91SAM9x5 or later SAM9 chips, and SAMA5 chips.
- atmel,pmecc-cap : error correct capability for Programmable Multibit ECC
- Controller. Supported values are: 2, 4, 8, 12, 24.
+ Controller. Supported values are: 2, 4, 8, 12, 24. SAMA5D2 also supports
+ 32.
- atmel,pmecc-sector-size : sector size for ECC computation. Supported values
are: 512, 1024.
- atmel,pmecc-lookup-table-offset : includes two offsets of lookup table in ROM
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 6fe50e2d291f..920a0a315a60 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -474,6 +474,7 @@ static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
* 8-bits 13-bytes 14-bytes
* 12-bits 20-bytes 21-bytes
* 24-bits 39-bytes 42-bytes
+ * 32-bits 52-bytes 56-bytes
*/
static int pmecc_get_ecc_bytes(int cap, int sector_size)
{
@@ -1022,6 +1023,9 @@ static void atmel_pmecc_core_init(struct mtd_info *mtd)
case 24:
val = PMECC_CFG_BCH_ERR24;
break;
+ case 32:
+ val = PMECC_CFG_BCH_ERR32;
+ break;
}

if (host->pmecc_sector_size == 512)
@@ -1083,6 +1087,9 @@ static int pmecc_choose_ecc(struct atmel_nand_host *host,

/* If device tree doesn't specify, use NAND's minimum ECC parameters */
if (host->pmecc_corr_cap == 0) {
+ if (*cap > host->caps->pmecc_max_correction)
+ return -EINVAL;
+
/* use the most fitable ecc bits (the near bigger one ) */
if (*cap <= 2)
host->pmecc_corr_cap = 2;
@@ -1094,6 +1101,8 @@ static int pmecc_choose_ecc(struct atmel_nand_host *host,
host->pmecc_corr_cap = 12;
else if (*cap <= 24)
host->pmecc_corr_cap = 24;
+ else if (*cap <= 32)
+ host->pmecc_corr_cap = 32;
else
return -EINVAL;
}
@@ -1554,10 +1563,16 @@ static int atmel_of_init_port(struct atmel_nand_host *host,
* them from NAND ONFI parameters.
*/
if (of_property_read_u32(np, "atmel,pmecc-cap", &val) == 0) {
- if ((val != 2) && (val != 4) && (val != 8) && (val != 12) &&
- (val != 24)) {
+ if (val > host->caps->pmecc_max_correction) {
+ dev_err(host->dev,
+ "Required ECC strength too high: %u max %u\n",
+ val, host->caps->pmecc_max_correction);
+ return -EINVAL;
+ }
+ if ((val != 2) && (val != 4) && (val != 8) &&
+ (val != 12) && (val != 24) && (val != 32)) {
dev_err(host->dev,
- "Unsupported PMECC correction capability: %d; should be 2, 4, 8, 12 or 24\n",
+ "Required ECC strength not supported: %u\n",
val);
return -EINVAL;
}
@@ -1567,7 +1582,7 @@ static int atmel_of_init_port(struct atmel_nand_host *host,
if (of_property_read_u32(np, "atmel,pmecc-sector-size", &val) == 0) {
if ((val != 512) && (val != 1024)) {
dev_err(host->dev,
- "Unsupported PMECC sector size: %d; should be 512 or 1024 bytes\n",
+ "Required ECC sector size not supported: %u\n",
val);
return -EINVAL;
}
diff --git a/drivers/mtd/nand/atmel_nand_ecc.h b/drivers/mtd/nand/atmel_nand_ecc.h
index ec964c43c932..834d694487bd 100644
--- a/drivers/mtd/nand/atmel_nand_ecc.h
+++ b/drivers/mtd/nand/atmel_nand_ecc.h
@@ -43,6 +43,7 @@
#define PMECC_CFG_BCH_ERR8 (2 << 0)
#define PMECC_CFG_BCH_ERR12 (3 << 0)
#define PMECC_CFG_BCH_ERR24 (4 << 0)
+#define PMECC_CFG_BCH_ERR32 (5 << 0)

#define PMECC_CFG_SECTOR512 (0 << 4)
#define PMECC_CFG_SECTOR1024 (1 << 4)
--
2.5.0