Merge branch 'master' of git://git.denx.de/u-boot-nand-flash

1 files changed, 196 insertions, 0 deletions

diff --git a/drivers/mtd/nand/omap_elm.c b/drivers/mtd/nand/omap_elm.c
new file mode 100644
index 000000000..2aa7807f3
--- /dev/null
+++ b/drivers/mtd/nand/omap_elm.c
@@ -0,0 +1,196 @@
+/*
+ * (C) Copyright 2010-2011 Texas Instruments, <www.ti.com>
+ * Mansoor Ahamed <mansoor.ahamed@ti.com>
+ *
+ * BCH Error Location Module (ELM) support.
+ *
+ * NOTE:
+ * 1. Supports only continuous mode. Dont see need for page mode in uboot
+ * 2. Supports only syndrome polynomial 0. i.e. poly local variable is
+ *    always set to ELM_DEFAULT_POLY. Dont see need for other polynomial
+ *    sets in uboot
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/errno.h>
+#include <asm/arch/cpu.h>
+#include <asm/omap_gpmc.h>
+#include <asm/omap_elm.h>
+
+#define ELM_DEFAULT_POLY (0)
+
+struct elm *elm_cfg;
+
+/**
+ * elm_load_syndromes - Load BCH syndromes based on nibble selection
+ * @syndrome: BCH syndrome
+ * @nibbles:
+ * @poly: Syndrome Polynomial set to use
+ *
+ * Load BCH syndromes based on nibble selection
+ */
+static void elm_load_syndromes(u8 *syndrome, u32 nibbles, u8 poly)
+{
+	u32 *ptr;
+	u32 val;
+
+	/* reg 0 */
+	ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[0];
+	val = syndrome[0] | (syndrome[1] << 8) | (syndrome[2] << 16) |
+				(syndrome[3] << 24);
+	writel(val, ptr);
+	/* reg 1 */
+	ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[1];
+	val = syndrome[4] | (syndrome[5] << 8) | (syndrome[6] << 16) |
+				(syndrome[7] << 24);
+	writel(val, ptr);
+
+	/* BCH 8-bit with 26 nibbles (4*8=32) */
+	if (nibbles > 13) {
+		/* reg 2 */
+		ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[2];
+		val = syndrome[8] | (syndrome[9] << 8) | (syndrome[10] << 16) |
+				(syndrome[11] << 24);
+		writel(val, ptr);
+		/* reg 3 */
+		ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[3];
+		val = syndrome[12] | (syndrome[13] << 8) |
+			(syndrome[14] << 16) | (syndrome[15] << 24);
+		writel(val, ptr);
+	}
+
+	/* BCH 16-bit with 52 nibbles (7*8=56) */
+	if (nibbles > 26) {
+		/* reg 4 */
+		ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[4];
+		val = syndrome[16] | (syndrome[17] << 8) |
+			(syndrome[18] << 16) | (syndrome[19] << 24);
+		writel(val, ptr);
+
+		/* reg 5 */
+		ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[5];
+		val = syndrome[20] | (syndrome[21] << 8) |
+			(syndrome[22] << 16) | (syndrome[23] << 24);
+		writel(val, ptr);
+
+		/* reg 6 */
+		ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6];
+		val = syndrome[24] | (syndrome[25] << 8) |
+			(syndrome[26] << 16) | (syndrome[27] << 24);
+		writel(val, ptr);
+	}
+}
+
+/**
+ * elm_check_errors - Check for BCH errors and return error locations
+ * @syndrome: BCH syndrome
+ * @nibbles:
+ * @error_count: Returns number of errrors in the syndrome
+ * @error_locations: Returns error locations (in decimal) in this array
+ *
+ * Check the provided syndrome for BCH errors and return error count
+ * and locations in the array passed. Returns -1 if error is not correctable,
+ * else returns 0
+ */
+int elm_check_error(u8 *syndrome, u32 nibbles, u32 *error_count,
+		u32 *error_locations)
+{
+	u8 poly = ELM_DEFAULT_POLY;
+	s8 i;
+	u32 location_status;
+
+	elm_load_syndromes(syndrome, nibbles, poly);
+
+	/* start processing */
+	writel((readl(&elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6])
+				| ELM_SYNDROME_FRAGMENT_6_SYNDROME_VALID),
+		&elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6]);
+
+	/* wait for processing to complete */
+	while ((readl(&elm_cfg->irqstatus) & (0x1 << poly)) != 0x1)
+		;
+	/* clear status */
+	writel((readl(&elm_cfg->irqstatus) | (0x1 << poly)),
+			&elm_cfg->irqstatus);
+
+	/* check if correctable */
+	location_status = readl(&elm_cfg->error_location[poly].location_status);
+	if (!(location_status & ELM_LOCATION_STATUS_ECC_CORRECTABLE_MASK))
+		return -1;
+
+	/* get error count */
+	*error_count = readl(&elm_cfg->error_location[poly].location_status) &
+					ELM_LOCATION_STATUS_ECC_NB_ERRORS_MASK;
+
+	for (i = 0; i < *error_count; i++) {
+		error_locations[i] =
+		     readl(&elm_cfg->error_location[poly].error_location_x[i]);
+	}
+
+	return 0;
+}
+
+
+/**
+ * elm_config - Configure ELM module
+ * @level: 4 / 8 / 16 bit BCH
+ *
+ * Configure ELM module based on BCH level.
+ * Set mode as continuous mode.
+ * Currently we are using only syndrome 0 and syndromes 1 to 6 are not used.
+ * Also, the mode is set only for syndrome 0
+ */
+int elm_config(enum bch_level level)
+{
+	u32 val;
+	u8 poly = ELM_DEFAULT_POLY;
+	u32 buffer_size = 0x7FF;
+
+	/* config size and level */
+	val = (u32)(level) & ELM_LOCATION_CONFIG_ECC_BCH_LEVEL_MASK;
+	val |= ((buffer_size << ELM_LOCATION_CONFIG_ECC_SIZE_POS) &
+				ELM_LOCATION_CONFIG_ECC_SIZE_MASK);
+	writel(val, &elm_cfg->location_config);
+
+	/* config continous mode */
+	/* enable interrupt generation for syndrome polynomial set */
+	writel((readl(&elm_cfg->irqenable) | (0x1 << poly)),
+			&elm_cfg->irqenable);
+	/* set continuous mode for the syndrome polynomial set */
+	writel((readl(&elm_cfg->page_ctrl) & ~(0x1 << poly)),
+			&elm_cfg->page_ctrl);
+
+	return 0;
+}
+
+/**
+ * elm_reset - Do a soft reset of ELM
+ *
+ * Perform a soft reset of ELM and return after reset is done.
+ */
+void elm_reset(void)
+{
+	/* initiate reset */
+	writel((readl(&elm_cfg->sysconfig) | ELM_SYSCONFIG_SOFTRESET),
+			&elm_cfg->sysconfig);
+
+	/* wait for reset complete and normal operation */
+	while ((readl(&elm_cfg->sysstatus) & ELM_SYSSTATUS_RESETDONE) !=
+		ELM_SYSSTATUS_RESETDONE)
+		;
+}
+
+/**
+ * elm_init - Initialize ELM module
+ *
+ * Initialize ELM support. Currently it does only base address init
+ * and ELM reset.
+ */
+void elm_init(void)
+{
+	elm_cfg = (struct elm *)ELM_BASE;
+	elm_reset();
+}