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 <asm/arch/cpu.h>
20 #include <asm/omap_gpmc.h>
21 #include <asm/arch/elm.h>
23 #define ELM_DEFAULT_POLY (0)
28 * elm_load_syndromes - Load BCH syndromes based on nibble selection
29 * @syndrome: BCH syndrome
31 * @poly: Syndrome Polynomial set to use
33 * Load BCH syndromes based on nibble selection
35 static void elm_load_syndromes(u8 *syndrome, u32 nibbles, u8 poly)
41 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[0];
42 val = syndrome[0] | (syndrome[1] << 8) | (syndrome[2] << 16) |
46 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[1];
47 val = syndrome[4] | (syndrome[5] << 8) | (syndrome[6] << 16) |
51 /* BCH 8-bit with 26 nibbles (4*8=32) */
54 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[2];
55 val = syndrome[8] | (syndrome[9] << 8) | (syndrome[10] << 16) |
59 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[3];
60 val = syndrome[12] | (syndrome[13] << 8) |
61 (syndrome[14] << 16) | (syndrome[15] << 24);
65 /* BCH 16-bit with 52 nibbles (7*8=56) */
68 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[4];
69 val = syndrome[16] | (syndrome[17] << 8) |
70 (syndrome[18] << 16) | (syndrome[19] << 24);
74 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[5];
75 val = syndrome[20] | (syndrome[21] << 8) |
76 (syndrome[22] << 16) | (syndrome[23] << 24);
80 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6];
81 val = syndrome[24] | (syndrome[25] << 8) |
82 (syndrome[26] << 16) | (syndrome[27] << 24);
88 * elm_check_errors - Check for BCH errors and return error locations
89 * @syndrome: BCH syndrome
91 * @error_count: Returns number of errrors in the syndrome
92 * @error_locations: Returns error locations (in decimal) in this array
94 * Check the provided syndrome for BCH errors and return error count
95 * and locations in the array passed. Returns -1 if error is not correctable,
98 int elm_check_error(u8 *syndrome, u32 nibbles, u32 *error_count,
101 u8 poly = ELM_DEFAULT_POLY;
105 elm_load_syndromes(syndrome, nibbles, poly);
107 /* start processing */
108 writel((readl(&elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6])
109 | ELM_SYNDROME_FRAGMENT_6_SYNDROME_VALID),
110 &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6]);
112 /* wait for processing to complete */
113 while ((readl(&elm_cfg->irqstatus) & (0x1 << poly)) != 0x1)
116 writel((readl(&elm_cfg->irqstatus) | (0x1 << poly)),
117 &elm_cfg->irqstatus);
119 /* check if correctable */
120 location_status = readl(&elm_cfg->error_location[poly].location_status);
121 if (!(location_status & ELM_LOCATION_STATUS_ECC_CORRECTABLE_MASK))
124 /* get error count */
125 *error_count = readl(&elm_cfg->error_location[poly].location_status) &
126 ELM_LOCATION_STATUS_ECC_NB_ERRORS_MASK;
128 for (i = 0; i < *error_count; i++) {
130 readl(&elm_cfg->error_location[poly].error_location_x[i]);
138 * elm_config - Configure ELM module
139 * @level: 4 / 8 / 16 bit BCH
141 * Configure ELM module based on BCH level.
142 * Set mode as continuous mode.
143 * Currently we are using only syndrome 0 and syndromes 1 to 6 are not used.
144 * Also, the mode is set only for syndrome 0
146 int elm_config(enum bch_level level)
149 u8 poly = ELM_DEFAULT_POLY;
150 u32 buffer_size = 0x7FF;
152 /* config size and level */
153 val = (u32)(level) & ELM_LOCATION_CONFIG_ECC_BCH_LEVEL_MASK;
154 val |= ((buffer_size << ELM_LOCATION_CONFIG_ECC_SIZE_POS) &
155 ELM_LOCATION_CONFIG_ECC_SIZE_MASK);
156 writel(val, &elm_cfg->location_config);
158 /* config continous mode */
159 /* enable interrupt generation for syndrome polynomial set */
160 writel((readl(&elm_cfg->irqenable) | (0x1 << poly)),
161 &elm_cfg->irqenable);
162 /* set continuous mode for the syndrome polynomial set */
163 writel((readl(&elm_cfg->page_ctrl) & ~(0x1 << poly)),
164 &elm_cfg->page_ctrl);
170 * elm_reset - Do a soft reset of ELM
172 * Perform a soft reset of ELM and return after reset is done.
177 writel((readl(&elm_cfg->sysconfig) | ELM_SYSCONFIG_SOFTRESET),
178 &elm_cfg->sysconfig);
180 /* wait for reset complete and normal operation */
181 while ((readl(&elm_cfg->sysstatus) & ELM_SYSSTATUS_RESETDONE) !=
182 ELM_SYSSTATUS_RESETDONE)
187 * elm_init - Initialize ELM module
189 * Initialize ELM support. Currently it does only base address init
194 elm_cfg = (struct elm *)ELM_BASE;