--- /dev/null
+/*
+ * (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 <linux/mtd/omap_gpmc.h>
+#include <linux/mtd/omap_elm.h>
+#include <asm/arch/hardware.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();
+}
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