1 /* 2 * (C) Copyright 2010-2011 Texas Instruments, <www.ti.com> 3 * Mansoor Ahamed <mansoor.ahamed@ti.com> 4 * 5 * BCH Error Location Module (ELM) support. 6 * 7 * NOTE: 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 11 * sets in uboot 12 * 13 * SPDX-License-Identifier: GPL-2.0+ 14 */ 15 16 #include <common.h> 17 #include <asm/io.h> 18 #include <linux/errno.h> 19 #include <linux/mtd/omap_elm.h> 20 #include <asm/arch/hardware.h> 21 22 #define DRIVER_NAME "omap-elm" 23 #define ELM_DEFAULT_POLY (0) 24 25 struct elm *elm_cfg; 26 27 /** 28 * elm_load_syndromes - Load BCH syndromes based on bch_type selection 29 * @syndrome: BCH syndrome 30 * @bch_type: BCH4/BCH8/BCH16 31 * @poly: Syndrome Polynomial set to use 32 */ 33 static void elm_load_syndromes(u8 *syndrome, enum bch_level bch_type, u8 poly) 34 { 35 u32 *ptr; 36 u32 val; 37 38 /* reg 0 */ 39 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[0]; 40 val = syndrome[0] | (syndrome[1] << 8) | (syndrome[2] << 16) | 41 (syndrome[3] << 24); 42 writel(val, ptr); 43 /* reg 1 */ 44 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[1]; 45 val = syndrome[4] | (syndrome[5] << 8) | (syndrome[6] << 16) | 46 (syndrome[7] << 24); 47 writel(val, ptr); 48 49 if (bch_type == BCH_8_BIT || bch_type == BCH_16_BIT) { 50 /* reg 2 */ 51 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[2]; 52 val = syndrome[8] | (syndrome[9] << 8) | (syndrome[10] << 16) | 53 (syndrome[11] << 24); 54 writel(val, ptr); 55 /* reg 3 */ 56 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[3]; 57 val = syndrome[12] | (syndrome[13] << 8) | 58 (syndrome[14] << 16) | (syndrome[15] << 24); 59 writel(val, ptr); 60 } 61 62 if (bch_type == BCH_16_BIT) { 63 /* reg 4 */ 64 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[4]; 65 val = syndrome[16] | (syndrome[17] << 8) | 66 (syndrome[18] << 16) | (syndrome[19] << 24); 67 writel(val, ptr); 68 69 /* reg 5 */ 70 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[5]; 71 val = syndrome[20] | (syndrome[21] << 8) | 72 (syndrome[22] << 16) | (syndrome[23] << 24); 73 writel(val, ptr); 74 75 /* reg 6 */ 76 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6]; 77 val = syndrome[24] | (syndrome[25] << 8) | 78 (syndrome[26] << 16) | (syndrome[27] << 24); 79 writel(val, ptr); 80 } 81 } 82 83 /** 84 * elm_check_errors - Check for BCH errors and return error locations 85 * @syndrome: BCH syndrome 86 * @bch_type: BCH4/BCH8/BCH16 87 * @error_count: Returns number of errrors in the syndrome 88 * @error_locations: Returns error locations (in decimal) in this array 89 * 90 * Check the provided syndrome for BCH errors and return error count 91 * and locations in the array passed. Returns -1 if error is not correctable, 92 * else returns 0 93 */ 94 int elm_check_error(u8 *syndrome, enum bch_level bch_type, u32 *error_count, 95 u32 *error_locations) 96 { 97 u8 poly = ELM_DEFAULT_POLY; 98 s8 i; 99 u32 location_status; 100 101 elm_load_syndromes(syndrome, bch_type, poly); 102 103 /* start processing */ 104 writel((readl(&elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6]) 105 | ELM_SYNDROME_FRAGMENT_6_SYNDROME_VALID), 106 &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6]); 107 108 /* wait for processing to complete */ 109 while ((readl(&elm_cfg->irqstatus) & (0x1 << poly)) != 0x1) 110 ; 111 /* clear status */ 112 writel((readl(&elm_cfg->irqstatus) | (0x1 << poly)), 113 &elm_cfg->irqstatus); 114 115 /* check if correctable */ 116 location_status = readl(&elm_cfg->error_location[poly].location_status); 117 if (!(location_status & ELM_LOCATION_STATUS_ECC_CORRECTABLE_MASK)) { 118 printf("%s: uncorrectable ECC errors\n", DRIVER_NAME); 119 return -EBADMSG; 120 } 121 122 /* get error count */ 123 *error_count = readl(&elm_cfg->error_location[poly].location_status) & 124 ELM_LOCATION_STATUS_ECC_NB_ERRORS_MASK; 125 126 for (i = 0; i < *error_count; i++) { 127 error_locations[i] = 128 readl(&elm_cfg->error_location[poly].error_location_x[i]); 129 } 130 131 return 0; 132 } 133 134 135 /** 136 * elm_config - Configure ELM module 137 * @level: 4 / 8 / 16 bit BCH 138 * 139 * Configure ELM module based on BCH level. 140 * Set mode as continuous mode. 141 * Currently we are using only syndrome 0 and syndromes 1 to 6 are not used. 142 * Also, the mode is set only for syndrome 0 143 */ 144 int elm_config(enum bch_level level) 145 { 146 u32 val; 147 u8 poly = ELM_DEFAULT_POLY; 148 u32 buffer_size = 0x7FF; 149 150 /* config size and level */ 151 val = (u32)(level) & ELM_LOCATION_CONFIG_ECC_BCH_LEVEL_MASK; 152 val |= ((buffer_size << ELM_LOCATION_CONFIG_ECC_SIZE_POS) & 153 ELM_LOCATION_CONFIG_ECC_SIZE_MASK); 154 writel(val, &elm_cfg->location_config); 155 156 /* config continous mode */ 157 /* enable interrupt generation for syndrome polynomial set */ 158 writel((readl(&elm_cfg->irqenable) | (0x1 << poly)), 159 &elm_cfg->irqenable); 160 /* set continuous mode for the syndrome polynomial set */ 161 writel((readl(&elm_cfg->page_ctrl) & ~(0x1 << poly)), 162 &elm_cfg->page_ctrl); 163 164 return 0; 165 } 166 167 /** 168 * elm_reset - Do a soft reset of ELM 169 * 170 * Perform a soft reset of ELM and return after reset is done. 171 */ 172 void elm_reset(void) 173 { 174 /* initiate reset */ 175 writel((readl(&elm_cfg->sysconfig) | ELM_SYSCONFIG_SOFTRESET), 176 &elm_cfg->sysconfig); 177 178 /* wait for reset complete and normal operation */ 179 while ((readl(&elm_cfg->sysstatus) & ELM_SYSSTATUS_RESETDONE) != 180 ELM_SYSSTATUS_RESETDONE) 181 ; 182 } 183 184 /** 185 * elm_init - Initialize ELM module 186 * 187 * Initialize ELM support. Currently it does only base address init 188 * and ELM reset. 189 */ 190 void elm_init(void) 191 { 192 elm_cfg = (struct elm *)ELM_BASE; 193 elm_reset(); 194 } 195