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770d7c39 JCPV |
1 | /* |
2 | * Copyright 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> | |
3 | * | |
4 | * OF helpers for mtd. | |
5 | * | |
6 | * This file is released under the GPLv2 | |
7 | * | |
8 | */ | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/of_mtd.h> | |
11 | #include <linux/mtd/nand.h> | |
12 | #include <linux/export.h> | |
13 | ||
14 | /** | |
15 | * It maps 'enum nand_ecc_modes_t' found in include/linux/mtd/nand.h | |
16 | * into the device tree binding of 'nand-ecc', so that MTD | |
17 | * device driver can get nand ecc from device tree. | |
18 | */ | |
19 | static const char *nand_ecc_modes[] = { | |
20 | [NAND_ECC_NONE] = "none", | |
21 | [NAND_ECC_SOFT] = "soft", | |
22 | [NAND_ECC_HW] = "hw", | |
23 | [NAND_ECC_HW_SYNDROME] = "hw_syndrome", | |
24 | [NAND_ECC_HW_OOB_FIRST] = "hw_oob_first", | |
25 | [NAND_ECC_SOFT_BCH] = "soft_bch", | |
26 | }; | |
27 | ||
28 | /** | |
29 | * of_get_nand_ecc_mode - Get nand ecc mode for given device_node | |
30 | * @np: Pointer to the given device_node | |
31 | * | |
32 | * The function gets ecc mode string from property 'nand-ecc-mode', | |
33 | * and return its index in nand_ecc_modes table, or errno in error case. | |
34 | */ | |
e95d8aaf | 35 | int of_get_nand_ecc_mode(struct device_node *np) |
770d7c39 JCPV |
36 | { |
37 | const char *pm; | |
38 | int err, i; | |
39 | ||
40 | err = of_property_read_string(np, "nand-ecc-mode", &pm); | |
41 | if (err < 0) | |
42 | return err; | |
43 | ||
44 | for (i = 0; i < ARRAY_SIZE(nand_ecc_modes); i++) | |
45 | if (!strcasecmp(pm, nand_ecc_modes[i])) | |
46 | return i; | |
47 | ||
48 | return -ENODEV; | |
49 | } | |
50 | EXPORT_SYMBOL_GPL(of_get_nand_ecc_mode); | |
51 | ||
6d9434eb EG |
52 | /** |
53 | * of_get_nand_ecc_step_size - Get ECC step size associated to | |
54 | * the required ECC strength (see below). | |
55 | * @np: Pointer to the given device_node | |
56 | * | |
57 | * return the ECC step size, or errno in error case. | |
58 | */ | |
59 | int of_get_nand_ecc_step_size(struct device_node *np) | |
60 | { | |
61 | int ret; | |
62 | u32 val; | |
63 | ||
64 | ret = of_property_read_u32(np, "nand-ecc-step-size", &val); | |
65 | return ret ? ret : val; | |
66 | } | |
67 | EXPORT_SYMBOL_GPL(of_get_nand_ecc_step_size); | |
68 | ||
69 | /** | |
70 | * of_get_nand_ecc_strength - Get required ECC strength over the | |
71 | * correspnding step size as defined by 'nand-ecc-size' | |
72 | * @np: Pointer to the given device_node | |
73 | * | |
74 | * return the ECC strength, or errno in error case. | |
75 | */ | |
76 | int of_get_nand_ecc_strength(struct device_node *np) | |
77 | { | |
78 | int ret; | |
79 | u32 val; | |
80 | ||
81 | ret = of_property_read_u32(np, "nand-ecc-strength", &val); | |
82 | return ret ? ret : val; | |
83 | } | |
84 | EXPORT_SYMBOL_GPL(of_get_nand_ecc_strength); | |
85 | ||
770d7c39 JCPV |
86 | /** |
87 | * of_get_nand_bus_width - Get nand bus witdh for given device_node | |
88 | * @np: Pointer to the given device_node | |
89 | * | |
90 | * return bus width option, or errno in error case. | |
91 | */ | |
92 | int of_get_nand_bus_width(struct device_node *np) | |
93 | { | |
94 | u32 val; | |
95 | ||
96 | if (of_property_read_u32(np, "nand-bus-width", &val)) | |
97 | return 8; | |
98 | ||
99 | switch(val) { | |
100 | case 8: | |
101 | case 16: | |
102 | return val; | |
103 | default: | |
104 | return -EIO; | |
105 | } | |
106 | } | |
107 | EXPORT_SYMBOL_GPL(of_get_nand_bus_width); | |
108 | ||
109 | /** | |
110 | * of_get_nand_on_flash_bbt - Get nand on flash bbt for given device_node | |
111 | * @np: Pointer to the given device_node | |
112 | * | |
113 | * return true if present false other wise | |
114 | */ | |
115 | bool of_get_nand_on_flash_bbt(struct device_node *np) | |
116 | { | |
117 | return of_property_read_bool(np, "nand-on-flash-bbt"); | |
118 | } | |
119 | EXPORT_SYMBOL_GPL(of_get_nand_on_flash_bbt); |