diff mbox

[v4,4/5] mtd: atmel_nand: Support 32-bit ECC strength

Message ID 1455098187-9442-5-git-send-email-romain.izard.pro@gmail.com
State Accepted
Headers show

Commit Message

Romain Izard Feb. 10, 2016, 9:56 a.m. UTC 
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 use this new setting.

For the binding:
Acked-by: Rob Herring <robh@kernel.org>

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Tested-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
v4: collect Tested-By and Reviewed-by tags
v3: no change
v2: split message rewording and binding rewording into their own patches

 Documentation/devicetree/bindings/mtd/atmel-nand.txt |  3 ++-
 drivers/mtd/nand/atmel_nand.c                        | 19 +++++++++++++++++--
 drivers/mtd/nand/atmel_nand_ecc.h                    |  1 +
 3 files changed, 20 insertions(+), 3 deletions(-)

Comments

Brian Norris Feb. 12, 2016, 6:30 p.m. UTC | #1 
On Wed, Feb 10, 2016 at 10:56:26AM +0100, Romain Izard wrote:
>  Documentation/devicetree/bindings/mtd/atmel-nand.txt |  3 ++-
>  drivers/mtd/nand/atmel_nand.c                        | 19 +++++++++++++++++--
>  drivers/mtd/nand/atmel_nand_ecc.h                    |  1 +
>  3 files changed, 20 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> index e1887b7d7e53..d53aba98fbc9 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,
>    capable of BCH encoding and decoding, on devices where it is present.
>  - 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. If the compatible string

Looks like you could be using the common 'nand-ecc-strength' binding
here.

> +  is "atmel,sama5d2-nand", 32 is also valid.
>  - atmel,pmecc-sector-size : sector size for ECC computation. Supported values
>    are: 512, 1024.

And 'nand-ecc-step-size' here.

>  - atmel,pmecc-lookup-table-offset : includes two offsets of lookup table in ROM

Of course we can't break backward compatibility, but it'd be nice if you
made sure this worked with the generic bindings.

Regards,
Brian
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
index e1887b7d7e53..d53aba98fbc9 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,
   capable of BCH encoding and decoding, on devices where it is present.
 - 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. If the compatible string
+  is "atmel,sama5d2-nand", 32 is also valid.
 - 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 00fa71045805..aaad1b98dd0d 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -475,6 +475,7 @@  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)
 {
@@ -1024,6 +1025,9 @@  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)
@@ -1085,6 +1089,9 @@  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;
@@ -1096,6 +1103,8 @@  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;
 	}
@@ -1554,8 +1563,14 @@  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,
 				"Required ECC strength not supported: %u\n",
 				val);
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)