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