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 static struct elm *elm_cfg;
43 * elm_load_syndromes - Load BCH syndromes based on nibble selection
44 * @syndrome: BCH syndrome
46 * @poly: Syndrome Polynomial set to use
48 * Load BCH syndromes based on nibble selection
50 static void elm_load_syndromes(u8 *syndrome, u32 nibbles, u8 poly)
56 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[0];
57 val = syndrome[0] | (syndrome[1] << 8) | (syndrome[2] << 16) |
61 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[1];
62 val = syndrome[4] | (syndrome[5] << 8) | (syndrome[6] << 16) |
66 /* BCH 8-bit with 26 nibbles (4*8=32) */
69 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[2];
70 val = syndrome[8] | (syndrome[9] << 8) | (syndrome[10] << 16) |
74 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[3];
75 val = syndrome[12] | (syndrome[13] << 8) | (syndrome[14] << 16) |
80 /* BCH 16-bit with 52 nibbles (7*8=56) */
83 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[4];
84 val = syndrome[16] | (syndrome[17] << 8) | (syndrome[18] << 16) |
89 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[5];
90 val = syndrome[20] | (syndrome[21] << 8) | (syndrome[22] << 16) |
95 ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6];
96 val = syndrome[24] | (syndrome[25] << 8) | (syndrome[26] << 16) |
103 * elm_check_errors - Check for BCH errors and return error locations
104 * @syndrome: BCH syndrome
106 * @error_count: Returns number of errrors in the syndrome
107 * @error_locations: Returns error locations (in decimal) in this array
109 * Check the provided syndrome for BCH errors and return error count
110 * and locations in the array passed. Returns -1 if error is not correctable,
113 int elm_check_error(u8 *syndrome, u32 nibbles, u32 *error_count,
114 u32 *error_locations)
116 u8 poly = ELM_DEFAULT_POLY;
120 elm_load_syndromes(syndrome, nibbles, poly);
122 /* start processing */
123 writel((readl(&elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6])
124 | ELM_SYNDROME_FRAGMENT_6_SYNDROME_VALID),
125 &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6]);
127 /* wait for processing to complete */
128 while((readl(&elm_cfg->irqstatus) & (0x1 << poly)) != 0x1);
130 writel((readl(&elm_cfg->irqstatus) | (0x1 << poly)), &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
152 * @buffer_size: Buffer size in bytes
154 * Configure ELM module based on BCH level and buffer size passed.
155 * Set mode as continuous mode.
156 * Currently we are using only syndrome 0 and syndromes 1 to 6 are not used.
157 * Also, the mode is set only for syndrome 0
159 /* int elm_config(enum bch_level level, u32 buffer_size) */
160 int elm_config(enum bch_level level)
163 u8 poly = ELM_DEFAULT_POLY;
164 u32 buffer_size= 0x7FF;
166 /* config size and level */
167 val = (u32)(level) & ELM_LOCATION_CONFIG_ECC_BCH_LEVEL_MASK;
168 val |= ((buffer_size << ELM_LOCATION_CONFIG_ECC_SIZE_POS) &
169 ELM_LOCATION_CONFIG_ECC_SIZE_MASK);
170 writel(val, &elm_cfg->location_config);
172 /* config continous mode */
173 /* enable interrupt generation for syndrome polynomial set */
174 writel((readl(&elm_cfg->irqenable) | (0x1 << poly)), &elm_cfg->irqenable);
175 /* set continuous mode for the syndrome polynomial set */
176 writel((readl(&elm_cfg->page_ctrl) & ~(0x1 << poly)), &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);
198 * elm_init - Initialize ELM module
200 * Initialize ELM support. Currently it does only base address init
203 void elm_init( void )
205 elm_cfg = (struct elm *)ELM_BASE;