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
25 /* make sure this variable does not end up in bss
26 * because that would corrupt the relocation section
27 * that is overlayed with the bss section
29 static struct elm *elm_cfg __attribute__((section(".data")));
32 * elm_load_syndromes - Load BCH syndromes based on nibble selection
33 * @syndrome: BCH syndrome
35 * @poly: Syndrome Polynomial set to use
37 * Load BCH syndromes based on nibble selection
39 static void elm_load_syndromes(u8 *syndrome, u32 nibbles, u8 poly)
42 struct syndrome *sf = &elm_cfg->syndrome_fragments[poly];
45 val = syndrome[0] | (syndrome[1] << 8) | (syndrome[2] << 16) |
47 writel(val, &sf->syndrome_fragment_x[0]);
50 val = syndrome[4] | (syndrome[5] << 8) | (syndrome[6] << 16) |
52 writel(val, &sf->syndrome_fragment_x[1]);
54 /* BCH 8-bit with 26 nibbles (4*8=32) */
57 val = syndrome[8] | (syndrome[9] << 8) | (syndrome[10] << 16) |
59 writel(val, &sf->syndrome_fragment_x[2]);
62 val = syndrome[12] | (syndrome[13] << 8) | (syndrome[14] << 16) |
64 writel(val, &sf->syndrome_fragment_x[3]);
67 /* BCH 16-bit with 52 nibbles (7*8=56) */
70 val = syndrome[16] | (syndrome[17] << 8) | (syndrome[18] << 16) |
72 writel(val, &sf->syndrome_fragment_x[4]);
75 val = syndrome[20] | (syndrome[21] << 8) | (syndrome[22] << 16) |
77 writel(val, &sf->syndrome_fragment_x[5]);
80 val = syndrome[24] | (syndrome[25] << 8) | (syndrome[26] << 16) |
82 writel(val, &sf->syndrome_fragment_x[6]);
87 * elm_check_error - 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)));
114 writel((readl(&elm_cfg->irqstatus) & ~(0x1 << poly)),
115 &elm_cfg->irqstatus);
117 /* check if correctable */
118 location_status = readl(&elm_cfg->error_location[poly].location_status);
119 if (!(location_status & ELM_LOCATION_STATUS_ECC_CORRECTABLE_MASK))
122 /* get error count */
123 *error_count = readl(&elm_cfg->error_location[poly].location_status) &
124 ELM_LOCATION_STATUS_ECC_NB_ERRORS_MASK;
126 for (i = 0; i < *error_count; i++)
128 readl(&elm_cfg->error_location[poly].error_location_x[i]);
135 * elm_config - Configure ELM module
136 * @level: 4 / 8 / 16 bit BCH
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
143 int elm_config(enum bch_level level)
146 u8 poly = ELM_DEFAULT_POLY;
147 u32 buffer_size = 0x7FF;
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);
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);
167 * elm_reset - Do a soft reset of ELM
169 * Perform a soft reset of ELM and return after reset is done.
174 writel((readl(&elm_cfg->sysconfig) | ELM_SYSCONFIG_SOFTRESET),
175 &elm_cfg->sysconfig);
177 /* wait for reset complete and normal operation */
178 while ((readl(&elm_cfg->sysstatus) & ELM_SYSSTATUS_RESETDONE) !=
179 ELM_SYSSTATUS_RESETDONE)
184 * elm_init - Initialize ELM module
186 * Initialize ELM support. Currently it does only base address init
191 elm_cfg = (struct elm *)ELM_BASE;