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 * See file CREDITS for list of people who contributed to this
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License as
18 * published by the Free Software Foundation; either version 2 of
19 * the License, or (at your option) any later version.
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
34 #include <asm/errno.h>
35 #include <asm/arch/cpu.h>
36 #include <asm/arch/nand.h>
38 #define ELM_DEFAULT_POLY 0
40 /* make sure this variable does not end up in bss
41 * because that would corrupt the relocation section
42 * that is overlayed with the bss section
44 static struct elm *elm_cfg __attribute__((section(".data")));
47 * elm_load_syndromes - Load BCH syndromes based on nibble selection
48 * @syndrome: BCH syndrome
50 * @poly: Syndrome Polynomial set to use
52 * Load BCH syndromes based on nibble selection
54 static void elm_load_syndromes(u8 *syndrome, u32 nibbles, u8 poly)
57 struct syndrome *sf = &elm_cfg->syndrome_fragments[poly];
60 val = syndrome[0] | (syndrome[1] << 8) | (syndrome[2] << 16) |
62 writel(val, &sf->syndrome_fragment_x[0]);
65 val = syndrome[4] | (syndrome[5] << 8) | (syndrome[6] << 16) |
67 writel(val, &sf->syndrome_fragment_x[1]);
69 /* BCH 8-bit with 26 nibbles (4*8=32) */
72 val = syndrome[8] | (syndrome[9] << 8) | (syndrome[10] << 16) |
74 writel(val, &sf->syndrome_fragment_x[2]);
77 val = syndrome[12] | (syndrome[13] << 8) | (syndrome[14] << 16) |
79 writel(val, &sf->syndrome_fragment_x[3]);
82 /* BCH 16-bit with 52 nibbles (7*8=56) */
85 val = syndrome[16] | (syndrome[17] << 8) | (syndrome[18] << 16) |
87 writel(val, &sf->syndrome_fragment_x[4]);
90 val = syndrome[20] | (syndrome[21] << 8) | (syndrome[22] << 16) |
92 writel(val, &sf->syndrome_fragment_x[5]);
95 val = syndrome[24] | (syndrome[25] << 8) | (syndrome[26] << 16) |
97 writel(val, &sf->syndrome_fragment_x[6]);
102 * elm_check_error - Check for BCH errors and return error locations
103 * @syndrome: BCH syndrome
105 * @error_count: Returns number of errrors in the syndrome
106 * @error_locations: Returns error locations (in decimal) in this array
108 * Check the provided syndrome for BCH errors and return error count
109 * and locations in the array passed. Returns -1 if error is not correctable,
112 int elm_check_error(u8 *syndrome, u32 nibbles, u32 *error_count,
113 u32 *error_locations)
115 u8 poly = ELM_DEFAULT_POLY;
119 elm_load_syndromes(syndrome, nibbles, poly);
121 /* start processing */
122 writel((readl(&elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6])
123 | ELM_SYNDROME_FRAGMENT_6_SYNDROME_VALID),
124 &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6]);
126 /* wait for processing to complete */
127 while (!(readl(&elm_cfg->irqstatus) & (0x1 << poly)));
129 writel((readl(&elm_cfg->irqstatus) & ~(0x1 << poly)),
130 &elm_cfg->irqstatus);
132 /* check if correctable */
133 location_status = readl(&elm_cfg->error_location[poly].location_status);
134 if (!(location_status & ELM_LOCATION_STATUS_ECC_CORRECTABLE_MASK))
137 /* get error count */
138 *error_count = readl(&elm_cfg->error_location[poly].location_status) &
139 ELM_LOCATION_STATUS_ECC_NB_ERRORS_MASK;
141 for (i = 0; i < *error_count; i++)
143 readl(&elm_cfg->error_location[poly].error_location_x[i]);
150 * elm_config - Configure ELM module
151 * @level: 4 / 8 / 16 bit BCH
153 * Configure ELM module based on BCH level.
154 * Set mode as continuous mode.
155 * Currently we are using only syndrome 0 and syndromes 1 to 6 are not used.
156 * Also, the mode is set only for syndrome 0
158 int elm_config(enum bch_level level)
161 u8 poly = ELM_DEFAULT_POLY;
162 u32 buffer_size = 0x7FF;
164 /* config size and level */
165 val = (u32)(level) & ELM_LOCATION_CONFIG_ECC_BCH_LEVEL_MASK;
166 val |= ((buffer_size << ELM_LOCATION_CONFIG_ECC_SIZE_POS) &
167 ELM_LOCATION_CONFIG_ECC_SIZE_MASK);
168 writel(val, &elm_cfg->location_config);
170 /* config continous mode */
171 /* enable interrupt generation for syndrome polynomial set */
172 writel((readl(&elm_cfg->irqenable) | (0x1 << poly)),
173 &elm_cfg->irqenable);
174 /* set continuous mode for the syndrome polynomial set */
175 writel((readl(&elm_cfg->page_ctrl) & ~(0x1 << poly)),
176 &elm_cfg->page_ctrl);
182 * elm_reset - Do a soft reset of ELM
184 * Perform a soft reset of ELM and return after reset is done.
189 writel((readl(&elm_cfg->sysconfig) | ELM_SYSCONFIG_SOFTRESET),
190 &elm_cfg->sysconfig);
192 /* wait for reset complete and normal operation */
193 while ((readl(&elm_cfg->sysstatus) & ELM_SYSSTATUS_RESETDONE) !=
194 ELM_SYSSTATUS_RESETDONE)
199 * elm_init - Initialize ELM module
201 * Initialize ELM support. Currently it does only base address init
206 elm_cfg = (struct elm *)ELM_BASE;