1 // SPDX-License-Identifier: GPL-2.0+
3 * (C) Copyright 2010-2011 Texas Instruments, <www.ti.com>
4 * Mansoor Ahamed <mansoor.ahamed@ti.com>
6 * BCH Error Location Module (ELM) support.
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
17 #include <linux/errno.h>
18 #include <linux/mtd/omap_elm.h>
19 #include <asm/arch/hardware.h>
21 #define DRIVER_NAME "omap-elm"
22 #define ELM_DEFAULT_POLY (0)
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
32 static void elm_load_syndromes(u8
*syndrome
, enum bch_level bch_type
, u8 poly
)
38 ptr
= &elm_cfg
->syndrome_fragments
[poly
].syndrome_fragment_x
[0];
39 val
= syndrome
[0] | (syndrome
[1] << 8) | (syndrome
[2] << 16) |
43 ptr
= &elm_cfg
->syndrome_fragments
[poly
].syndrome_fragment_x
[1];
44 val
= syndrome
[4] | (syndrome
[5] << 8) | (syndrome
[6] << 16) |
48 if (bch_type
== BCH_8_BIT
|| bch_type
== BCH_16_BIT
) {
50 ptr
= &elm_cfg
->syndrome_fragments
[poly
].syndrome_fragment_x
[2];
51 val
= syndrome
[8] | (syndrome
[9] << 8) | (syndrome
[10] << 16) |
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);
61 if (bch_type
== BCH_16_BIT
) {
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);
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);
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);
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
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,
93 int elm_check_error(u8
*syndrome
, enum bch_level bch_type
, u32
*error_count
,
96 u8 poly
= ELM_DEFAULT_POLY
;
100 elm_load_syndromes(syndrome
, bch_type
, poly
);
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]);
107 /* wait for processing to complete */
108 while ((readl(&elm_cfg
->irqstatus
) & (0x1 << poly
)) != 0x1)
111 writel((readl(&elm_cfg
->irqstatus
) | (0x1 << poly
)),
112 &elm_cfg
->irqstatus
);
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
);
121 /* get error count */
122 *error_count
= readl(&elm_cfg
->error_location
[poly
].location_status
) &
123 ELM_LOCATION_STATUS_ECC_NB_ERRORS_MASK
;
125 for (i
= 0; i
< *error_count
; i
++) {
127 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
;