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 <linux/errno.h>
19 #include <linux/mtd/omap_elm.h>
20 #include <asm/arch/hardware.h>
22 #define DRIVER_NAME "omap-elm"
23 #define ELM_DEFAULT_POLY (0)
28 * elm_load_syndromes - Load BCH syndromes based on bch_type selection
29 * @syndrome: BCH syndrome
30 * @bch_type: BCH4/BCH8/BCH16
31 * @poly: Syndrome Polynomial set to use
33 static void elm_load_syndromes(u8
*syndrome
, enum bch_level bch_type
, u8 poly
)
39 ptr
= &elm_cfg
->syndrome_fragments
[poly
].syndrome_fragment_x
[0];
40 val
= syndrome
[0] | (syndrome
[1] << 8) | (syndrome
[2] << 16) |
44 ptr
= &elm_cfg
->syndrome_fragments
[poly
].syndrome_fragment_x
[1];
45 val
= syndrome
[4] | (syndrome
[5] << 8) | (syndrome
[6] << 16) |
49 if (bch_type
== BCH_8_BIT
|| bch_type
== BCH_16_BIT
) {
51 ptr
= &elm_cfg
->syndrome_fragments
[poly
].syndrome_fragment_x
[2];
52 val
= syndrome
[8] | (syndrome
[9] << 8) | (syndrome
[10] << 16) |
56 ptr
= &elm_cfg
->syndrome_fragments
[poly
].syndrome_fragment_x
[3];
57 val
= syndrome
[12] | (syndrome
[13] << 8) |
58 (syndrome
[14] << 16) | (syndrome
[15] << 24);
62 if (bch_type
== BCH_16_BIT
) {
64 ptr
= &elm_cfg
->syndrome_fragments
[poly
].syndrome_fragment_x
[4];
65 val
= syndrome
[16] | (syndrome
[17] << 8) |
66 (syndrome
[18] << 16) | (syndrome
[19] << 24);
70 ptr
= &elm_cfg
->syndrome_fragments
[poly
].syndrome_fragment_x
[5];
71 val
= syndrome
[20] | (syndrome
[21] << 8) |
72 (syndrome
[22] << 16) | (syndrome
[23] << 24);
76 ptr
= &elm_cfg
->syndrome_fragments
[poly
].syndrome_fragment_x
[6];
77 val
= syndrome
[24] | (syndrome
[25] << 8) |
78 (syndrome
[26] << 16) | (syndrome
[27] << 24);
84 * elm_check_errors - Check for BCH errors and return error locations
85 * @syndrome: BCH syndrome
86 * @bch_type: BCH4/BCH8/BCH16
87 * @error_count: Returns number of errrors in the syndrome
88 * @error_locations: Returns error locations (in decimal) in this array
90 * Check the provided syndrome for BCH errors and return error count
91 * and locations in the array passed. Returns -1 if error is not correctable,
94 int elm_check_error(u8
*syndrome
, enum bch_level bch_type
, u32
*error_count
,
97 u8 poly
= ELM_DEFAULT_POLY
;
101 elm_load_syndromes(syndrome
, bch_type
, poly
);
103 /* start processing */
104 writel((readl(&elm_cfg
->syndrome_fragments
[poly
].syndrome_fragment_x
[6])
105 | ELM_SYNDROME_FRAGMENT_6_SYNDROME_VALID
),
106 &elm_cfg
->syndrome_fragments
[poly
].syndrome_fragment_x
[6]);
108 /* wait for processing to complete */
109 while ((readl(&elm_cfg
->irqstatus
) & (0x1 << poly
)) != 0x1)
112 writel((readl(&elm_cfg
->irqstatus
) | (0x1 << poly
)),
113 &elm_cfg
->irqstatus
);
115 /* check if correctable */
116 location_status
= readl(&elm_cfg
->error_location
[poly
].location_status
);
117 if (!(location_status
& ELM_LOCATION_STATUS_ECC_CORRECTABLE_MASK
)) {
118 printf("%s: uncorrectable ECC errors\n", DRIVER_NAME
);
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
]);
136 * elm_config - Configure ELM module
137 * @level: 4 / 8 / 16 bit BCH
139 * Configure ELM module based on BCH level.
140 * Set mode as continuous mode.
141 * Currently we are using only syndrome 0 and syndromes 1 to 6 are not used.
142 * Also, the mode is set only for syndrome 0
144 int elm_config(enum bch_level level
)
147 u8 poly
= ELM_DEFAULT_POLY
;
148 u32 buffer_size
= 0x7FF;
150 /* config size and level */
151 val
= (u32
)(level
) & ELM_LOCATION_CONFIG_ECC_BCH_LEVEL_MASK
;
152 val
|= ((buffer_size
<< ELM_LOCATION_CONFIG_ECC_SIZE_POS
) &
153 ELM_LOCATION_CONFIG_ECC_SIZE_MASK
);
154 writel(val
, &elm_cfg
->location_config
);
156 /* config continous mode */
157 /* enable interrupt generation for syndrome polynomial set */
158 writel((readl(&elm_cfg
->irqenable
) | (0x1 << poly
)),
159 &elm_cfg
->irqenable
);
160 /* set continuous mode for the syndrome polynomial set */
161 writel((readl(&elm_cfg
->page_ctrl
) & ~(0x1 << poly
)),
162 &elm_cfg
->page_ctrl
);
168 * elm_reset - Do a soft reset of ELM
170 * Perform a soft reset of ELM and return after reset is done.
175 writel((readl(&elm_cfg
->sysconfig
) | ELM_SYSCONFIG_SOFTRESET
),
176 &elm_cfg
->sysconfig
);
178 /* wait for reset complete and normal operation */
179 while ((readl(&elm_cfg
->sysstatus
) & ELM_SYSSTATUS_RESETDONE
) !=
180 ELM_SYSSTATUS_RESETDONE
)
185 * elm_init - Initialize ELM module
187 * Initialize ELM support. Currently it does only base address init
192 elm_cfg
= (struct elm
*)ELM_BASE
;