[PATCH v12 1/2] MTD: at91: add dt parameters for Atmel PMECC

[Josh Wu]

Add DT support for PMECC parameters.

Signed-off-by: Josh Wu <josh.wu at atmel.com>
---
changes:
since v11
   1. update the documentation for reg parameter
   2. add one example for PMECC support.

 .../devicetree/bindings/mtd/atmel-nand.txt         |   40 ++++++++++++++-
 drivers/mtd/nand/atmel_nand.c                      |   52 +++++++++++++++++++-
 2 files changed, 90 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
index a200695..d555421 100644
--- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
@@ -3,7 +3,9 @@ Atmel NAND flash
 Required properties:
 - compatible : "atmel,at91rm9200-nand".
 - reg : should specify localbus address and size used for the chip,
-	and if availlable the ECC.
+	and hardware ECC controller if available.
+	If the hardware ECC is PMECC, it should contain address and size for
+	PMECC, PMECC Error Location controller and ROM which has lookup tables.
 - atmel,nand-addr-offset : offset for the address latch.
 - atmel,nand-cmd-offset : offset for the command latch.
 - #address-cells, #size-cells : Must be present if the device has sub-nodes
@@ -16,6 +18,15 @@ Optional properties:
 - nand-ecc-mode : String, operation mode of the NAND ecc mode, soft by default.
   Supported values are: "none", "soft", "hw", "hw_syndrome", "hw_oob_first",
   "soft_bch".
+- atmel,has-pmecc : boolean to enable Programmable Multibit ECC hardware.
+  Only supported by at91sam9x5 or later sam9 product.
+- atmel,pmecc-cap : error correct capability for Programmable Multibit ECC
+  Controller. Supported values are: 2, 4, 8, 12, 24.
+- 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
+  for different sector size. First one is for sector size 512, the next is for
+  sector size 1024.
 - nand-bus-width : 8 or 16 bus width if not present 8
 - nand-on-flash-bbt: boolean to enable on flash bbt option if not present false
 
@@ -39,3 +50,30 @@ nand0: nand at 40000000,0 {
 		...
 	};
 };
+
+/* for PMECC supported chips */
+nand0: nand at 40000000 {
+	compatible = "atmel,at91rm9200-nand";
+	#address-cells = <1>;
+	#size-cells = <1>;
+	reg = < 0x40000000 0x10000000	/* bus addr & size */
+		0xffffe000 0x00000600	/* PMECC addr & size */
+		0xffffe600 0x00000200	/* PMECC ERRLOC addr & size */
+		0x00100000 0x00100000	/* ROM addr & size */
+		>;
+	atmel,nand-addr-offset = <21>;	/* ale */
+	atmel,nand-cmd-offset = <22>;	/* cle */
+	nand-on-flash-bbt;
+	nand-ecc-mode = "hw";
+	atmel,has-pmecc;	/* enable PMECC */
+	atmel,pmecc-cap = <2>;
+	atmel,pmecc-sector-size = <512>;
+	atmel,pmecc-lookup-table-offset = <0x8000 0x10000>;
+	gpios = <&pioD 5 0	/* rdy */
+		 &pioD 4 0	/* nce */
+		 0		/* cd */
+		>;
+	partition at 0 {
+		...
+	};
+};
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 7a41a04..b97ad9f 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -93,6 +93,11 @@ struct atmel_nand_host {
 
 	struct completion	comp;
 	struct dma_chan		*dma_chan;
+
+	bool			has_pmecc;
+	u8			pmecc_corr_cap;
+	u16			pmecc_sector_size;
+	u32			pmecc_lookup_table_offset;
 };
 
 static int cpu_has_dma(void)
@@ -481,7 +486,8 @@ static void atmel_nand_hwctl(struct mtd_info *mtd, int mode)
 static int __devinit atmel_of_init_port(struct atmel_nand_host *host,
 					 struct device_node *np)
 {
-	u32 val;
+	u32 val, table_offset;
+	u32 offset[2];
 	int ecc_mode;
 	struct atmel_nand_data *board = &host->board;
 	enum of_gpio_flags flags;
@@ -517,6 +523,50 @@ static int __devinit atmel_of_init_port(struct atmel_nand_host *host,
 	board->enable_pin = of_get_gpio(np, 1);
 	board->det_pin = of_get_gpio(np, 2);
 
+	host->has_pmecc = of_property_read_bool(np, "atmel,has-pmecc");
+
+	if (!(board->ecc_mode == NAND_ECC_HW) || !host->has_pmecc)
+		return 0;	/* Not using PMECC */
+
+	/* use PMECC, get correction capability, sector size and lookup
+	 * table offset.
+	 */
+	if (of_property_read_u32(np, "atmel,pmecc-cap", &val) != 0) {
+		dev_err(host->dev, "Cannot decide PMECC Capability\n");
+		return -EINVAL;
+	} else if ((val != 2) && (val != 4) && (val != 8) && (val != 12) &&
+	    (val != 24)) {
+		dev_err(host->dev,
+			"Unsupported PMECC correction capability: %d; should be 2, 4, 8, 12 or 24\n",
+			val);
+		return -EINVAL;
+	}
+	host->pmecc_corr_cap = (u8)val;
+
+	if (of_property_read_u32(np, "atmel,pmecc-sector-size", &val) != 0) {
+		dev_err(host->dev, "Cannot decide PMECC Sector Size\n");
+		return -EINVAL;
+	} else if ((val != 512) && (val != 1024)) {
+		dev_err(host->dev,
+			"Unsupported PMECC sector size: %d; should be 512 or 1024 bytes\n",
+			val);
+		return -EINVAL;
+	}
+	host->pmecc_sector_size = (u16)val;
+
+	if (of_property_read_u32_array(np, "atmel,pmecc-lookup-table-offset",
+			offset, 2) != 0) {
+		dev_err(host->dev, "Cannot get PMECC lookup table offset\n");
+		return -EINVAL;
+	}
+	table_offset = host->pmecc_sector_size == 512 ? offset[0] : offset[1];
+
+	if (!table_offset) {
+		dev_err(host->dev, "Invalid PMECC lookup table offset\n");
+		return -EINVAL;
+	}
+	host->pmecc_lookup_table_offset = table_offset;
+
 	return 0;
 }
 #else
-- 
1.7.9.5