2 * (C) Copyright 2010-2011 Texas Instruments, <www.ti.com>
3 * Mansoor Ahamed <mansoor.ahamed@ti.com>
5 * BCH Error Location Module (ELM) support.
8 * 1. Supports only continuous mode. Dont see need for page mode in uboot
9 * 2. Supports only syndrome polynomial 0. i.e. poly local variable is
10 * always set to ELM_DEFAULT_POLY. Dont see need for other polynomial
13 * SPDX-License-Identifier: GPL-2.0+
18 #include <asm/errno.h>
19 #include <linux/mtd/omap_elm.h>
20 #include <asm/arch/hardware.h>
22 #define ELM_DEFAULT_POLY (0)
27 * elm_load_syndromes - Load BCH syndromes based on nibble selection
28 * @syndrome: BCH syndrome
30 * @poly: Syndrome Polynomial set to use
32 * Load BCH syndromes based on nibble selection
34 static void elm_load_syndromes(u8 *syndrome, u32 nibbles, u8 poly)
40 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[0];
41 val = syndrome[0] | (syndrome[1] << 8) | (syndrome[2] << 16) |
45 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[1];
46 val = syndrome[4] | (syndrome[5] << 8) | (syndrome[6] << 16) |
50 /* BCH 8-bit with 26 nibbles (4*8=32) */
53 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[2];
54 val = syndrome[8] | (syndrome[9] << 8) | (syndrome[10] << 16) |
58 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[3];
59 val = syndrome[12] | (syndrome[13] << 8) |
60 (syndrome[14] << 16) | (syndrome[15] << 24);
64 /* BCH 16-bit with 52 nibbles (7*8=56) */
67 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[4];
68 val = syndrome[16] | (syndrome[17] << 8) |
69 (syndrome[18] << 16) | (syndrome[19] << 24);
73 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[5];
74 val = syndrome[20] | (syndrome[21] << 8) |
75 (syndrome[22] << 16) | (syndrome[23] << 24);
79 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6];
80 val = syndrome[24] | (syndrome[25] << 8) |
81 (syndrome[26] << 16) | (syndrome[27] << 24);
87 * elm_check_errors - Check for BCH errors and return error locations
88 * @syndrome: BCH syndrome
90 * @error_count: Returns number of errrors in the syndrome
91 * @error_locations: Returns error locations (in decimal) in this array
93 * Check the provided syndrome for BCH errors and return error count
94 * and locations in the array passed. Returns -1 if error is not correctable,
97 int elm_check_error(u8 *syndrome, u32 nibbles, u32 *error_count,
100 u8 poly = ELM_DEFAULT_POLY;
104 elm_load_syndromes(syndrome, nibbles, poly);
106 /* start processing */
107 writel((readl(&elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6])
108 | ELM_SYNDROME_FRAGMENT_6_SYNDROME_VALID),
109 &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6]);
111 /* wait for processing to complete */
112 while ((readl(&elm_cfg->irqstatus) & (0x1 << poly)) != 0x1)
115 writel((readl(&elm_cfg->irqstatus) | (0x1 << poly)),
116 &elm_cfg->irqstatus);
118 /* check if correctable */
119 location_status = readl(&elm_cfg->error_location[poly].location_status);
120 if (!(location_status & ELM_LOCATION_STATUS_ECC_CORRECTABLE_MASK))
123 /* get error count */
124 *error_count = readl(&elm_cfg->error_location[poly].location_status) &
125 ELM_LOCATION_STATUS_ECC_NB_ERRORS_MASK;
127 for (i = 0; i < *error_count; i++) {
129 readl(&elm_cfg->error_location[poly].error_location_x[i]);
137 * elm_config - Configure ELM module
138 * @level: 4 / 8 / 16 bit BCH
140 * Configure ELM module based on BCH level.
141 * Set mode as continuous mode.
142 * Currently we are using only syndrome 0 and syndromes 1 to 6 are not used.
143 * Also, the mode is set only for syndrome 0
145 int elm_config(enum bch_level level)
148 u8 poly = ELM_DEFAULT_POLY;
149 u32 buffer_size = 0x7FF;
151 /* config size and level */
152 val = (u32)(level) & ELM_LOCATION_CONFIG_ECC_BCH_LEVEL_MASK;
153 val |= ((buffer_size << ELM_LOCATION_CONFIG_ECC_SIZE_POS) &
154 ELM_LOCATION_CONFIG_ECC_SIZE_MASK);
155 writel(val, &elm_cfg->location_config);
157 /* config continous mode */
158 /* enable interrupt generation for syndrome polynomial set */
159 writel((readl(&elm_cfg->irqenable) | (0x1 << poly)),
160 &elm_cfg->irqenable);
161 /* set continuous mode for the syndrome polynomial set */
162 writel((readl(&elm_cfg->page_ctrl) & ~(0x1 << poly)),
163 &elm_cfg->page_ctrl);
169 * elm_reset - Do a soft reset of ELM
171 * Perform a soft reset of ELM and return after reset is done.
176 writel((readl(&elm_cfg->sysconfig) | ELM_SYSCONFIG_SOFTRESET),
177 &elm_cfg->sysconfig);
179 /* wait for reset complete and normal operation */
180 while ((readl(&elm_cfg->sysstatus) & ELM_SYSSTATUS_RESETDONE) !=
181 ELM_SYSSTATUS_RESETDONE)
186 * elm_init - Initialize ELM module
188 * Initialize ELM support. Currently it does only base address init
193 elm_cfg = (struct elm *)ELM_BASE;