forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
of_mtd.c
119 lines (106 loc) · 2.83 KB
/
of_mtd.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
/*
* Copyright 2012 Jean-Christophe PLAGNIOL-VILLARD <[email protected]>
*
* OF helpers for mtd.
*
* This file is released under the GPLv2
*
*/
#include <linux/kernel.h>
#include <linux/of_mtd.h>
#include <linux/mtd/nand.h>
#include <linux/export.h>
/**
* It maps 'enum nand_ecc_modes_t' found in include/linux/mtd/nand.h
* into the device tree binding of 'nand-ecc', so that MTD
* device driver can get nand ecc from device tree.
*/
static const char *nand_ecc_modes[] = {
[NAND_ECC_NONE] = "none",
[NAND_ECC_SOFT] = "soft",
[NAND_ECC_HW] = "hw",
[NAND_ECC_HW_SYNDROME] = "hw_syndrome",
[NAND_ECC_HW_OOB_FIRST] = "hw_oob_first",
[NAND_ECC_SOFT_BCH] = "soft_bch",
};
/**
* of_get_nand_ecc_mode - Get nand ecc mode for given device_node
* @np: Pointer to the given device_node
*
* The function gets ecc mode string from property 'nand-ecc-mode',
* and return its index in nand_ecc_modes table, or errno in error case.
*/
int of_get_nand_ecc_mode(struct device_node *np)
{
const char *pm;
int err, i;
err = of_property_read_string(np, "nand-ecc-mode", &pm);
if (err < 0)
return err;
for (i = 0; i < ARRAY_SIZE(nand_ecc_modes); i++)
if (!strcasecmp(pm, nand_ecc_modes[i]))
return i;
return -ENODEV;
}
EXPORT_SYMBOL_GPL(of_get_nand_ecc_mode);
/**
* of_get_nand_ecc_step_size - Get ECC step size associated to
* the required ECC strength (see below).
* @np: Pointer to the given device_node
*
* return the ECC step size, or errno in error case.
*/
int of_get_nand_ecc_step_size(struct device_node *np)
{
int ret;
u32 val;
ret = of_property_read_u32(np, "nand-ecc-step-size", &val);
return ret ? ret : val;
}
EXPORT_SYMBOL_GPL(of_get_nand_ecc_step_size);
/**
* of_get_nand_ecc_strength - Get required ECC strength over the
* correspnding step size as defined by 'nand-ecc-size'
* @np: Pointer to the given device_node
*
* return the ECC strength, or errno in error case.
*/
int of_get_nand_ecc_strength(struct device_node *np)
{
int ret;
u32 val;
ret = of_property_read_u32(np, "nand-ecc-strength", &val);
return ret ? ret : val;
}
EXPORT_SYMBOL_GPL(of_get_nand_ecc_strength);
/**
* of_get_nand_bus_width - Get nand bus witdh for given device_node
* @np: Pointer to the given device_node
*
* return bus width option, or errno in error case.
*/
int of_get_nand_bus_width(struct device_node *np)
{
u32 val;
if (of_property_read_u32(np, "nand-bus-width", &val))
return 8;
switch(val) {
case 8:
case 16:
return val;
default:
return -EIO;
}
}
EXPORT_SYMBOL_GPL(of_get_nand_bus_width);
/**
* of_get_nand_on_flash_bbt - Get nand on flash bbt for given device_node
* @np: Pointer to the given device_node
*
* return true if present false other wise
*/
bool of_get_nand_on_flash_bbt(struct device_node *np)
{
return of_property_read_bool(np, "nand-on-flash-bbt");
}
EXPORT_SYMBOL_GPL(of_get_nand_on_flash_bbt);