mtd: nand: omap: add support for BCH16_ECC - GPMC driver updates

This patch add support for BCH16_ECC in GPMC (controller) driver:
- extends configuration space to include BCH16 registers
- extends parsing of DT binding for selecting BCH16 ecc-scheme

Signed-off-by: Pekon Gupta <pekon@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

arch/arm/mach-omap2/gpmc.c

@@ -68,6 +68,9 @@
 #define	GPMC_ECC_BCH_RESULT_1	0x244	/* not available on OMAP2 */
 #define	GPMC_ECC_BCH_RESULT_2	0x248	/* not available on OMAP2 */
 #define	GPMC_ECC_BCH_RESULT_3	0x24c	/* not available on OMAP2 */
+#define	GPMC_ECC_BCH_RESULT_4	0x300	/* not available on OMAP2 */
+#define	GPMC_ECC_BCH_RESULT_5	0x304	/* not available on OMAP2 */
+#define	GPMC_ECC_BCH_RESULT_6	0x308	/* not available on OMAP2 */
 
 /* GPMC ECC control settings */
 #define GPMC_ECC_CTRL_ECCCLEAR		0x100
@@ -666,6 +669,12 @@ void gpmc_update_nand_reg(struct gpmc_nand_regs *reg, int cs)
 					   GPMC_BCH_SIZE * i;
 		reg->gpmc_bch_result3[i] = gpmc_base + GPMC_ECC_BCH_RESULT_3 +
 					   GPMC_BCH_SIZE * i;
+		reg->gpmc_bch_result4[i] = gpmc_base + GPMC_ECC_BCH_RESULT_4 +
+					   i * GPMC_BCH_SIZE;
+		reg->gpmc_bch_result5[i] = gpmc_base + GPMC_ECC_BCH_RESULT_5 +
+					   i * GPMC_BCH_SIZE;
+		reg->gpmc_bch_result6[i] = gpmc_base + GPMC_ECC_BCH_RESULT_6 +
+					   i * GPMC_BCH_SIZE;
 	}
 }
 
@@ -1401,6 +1410,12 @@ static int gpmc_probe_nand_child(struct platform_device *pdev,
 		else
 			gpmc_nand_data->ecc_opt =
 				OMAP_ECC_BCH8_CODE_HW_DETECTION_SW;
+	else if (!strcmp(s, "bch16"))
+		if (gpmc_nand_data->elm_of_node)
+			gpmc_nand_data->ecc_opt =
+				OMAP_ECC_BCH16_CODE_HW;
+		else
+			pr_err("%s: BCH16 requires ELM support\n", __func__);
 	else
 		pr_err("%s: ti,nand-ecc-opt invalid value\n", __func__);
 

include/linux/platform_data/mtd-nand-omap2.h

@@ -31,6 +31,8 @@ enum omap_ecc {
 	OMAP_ECC_BCH8_CODE_HW_DETECTION_SW,
 	/* 8-bit  ECC calculation by GPMC, Error detection by ELM */
 	OMAP_ECC_BCH8_CODE_HW,
+	/* 16-bit ECC calculation by GPMC, Error detection by ELM */
+	OMAP_ECC_BCH16_CODE_HW,
 };
 
 struct gpmc_nand_regs {
@@ -50,6 +52,9 @@ struct gpmc_nand_regs {
 	void __iomem	*gpmc_bch_result1[GPMC_BCH_NUM_REMAINDER];
 	void __iomem	*gpmc_bch_result2[GPMC_BCH_NUM_REMAINDER];
 	void __iomem	*gpmc_bch_result3[GPMC_BCH_NUM_REMAINDER];
+	void __iomem	*gpmc_bch_result4[GPMC_BCH_NUM_REMAINDER];
+	void __iomem	*gpmc_bch_result5[GPMC_BCH_NUM_REMAINDER];
+	void __iomem	*gpmc_bch_result6[GPMC_BCH_NUM_REMAINDER];
 };
 
 struct omap_nand_platform_data {