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
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
/*
* Generic Syscon LEDs Driver
*
* Copyright (c) 2014, Linaro Limited
* Author: Linus Walleij <linus.walleij@linaro.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/leds.h>
/**
* struct syscon_led - state container for syscon based LEDs
* @cdev: LED class device for this LED
* @map: regmap to access the syscon device backing this LED
* @offset: the offset into the syscon regmap for the LED register
* @mask: the bit in the register corresponding to the LED
* @state: current state of the LED
*/
struct syscon_led {
struct led_classdev cdev;
struct regmap *map;
u32 offset;
u32 mask;
bool state;
};
static void syscon_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct syscon_led *sled =
container_of(led_cdev, struct syscon_led, cdev);
u32 val;
int ret;
if (value == LED_OFF) {
val = 0;
sled->state = false;
} else {
val = sled->mask;
sled->state = true;
}
ret = regmap_update_bits(sled->map, sled->offset, sled->mask, val);
if (ret < 0)
dev_err(sled->cdev.dev, "error updating LED status\n");
}
static int syscon_led_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct device *parent;
struct regmap *map;
struct syscon_led *sled;
const char *state;
int ret;
parent = dev->parent;
if (!parent) {
dev_err(dev, "no parent for syscon LED\n");
return -ENODEV;
}
map = syscon_node_to_regmap(parent->of_node);
if (IS_ERR(map)) {
dev_err(dev, "no regmap for syscon LED parent\n");
return PTR_ERR(map);
}
sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL);
if (!sled)
return -ENOMEM;
sled->map = map;
if (of_property_read_u32(np, "offset", &sled->offset))
return -EINVAL;
if (of_property_read_u32(np, "mask", &sled->mask))
return -EINVAL;
sled->cdev.name =
of_get_property(np, "label", NULL) ? : np->name;
sled->cdev.default_trigger =
of_get_property(np, "linux,default-trigger", NULL);
state = of_get_property(np, "default-state", NULL);
if (state) {
if (!strcmp(state, "keep")) {
u32 val;
ret = regmap_read(map, sled->offset, &val);
if (ret < 0)
return ret;
sled->state = !!(val & sled->mask);
} else if (!strcmp(state, "on")) {
sled->state = true;
ret = regmap_update_bits(map, sled->offset,
sled->mask,
sled->mask);
if (ret < 0)
return ret;
} else {
sled->state = false;
ret = regmap_update_bits(map, sled->offset,
sled->mask, 0);
if (ret < 0)
return ret;
}
}
sled->cdev.brightness_set = syscon_led_set;
ret = led_classdev_register(dev, &sled->cdev);
if (ret < 0)
return ret;
platform_set_drvdata(pdev, sled);
dev_info(dev, "registered LED %s\n", sled->cdev.name);
return 0;
}
static int syscon_led_remove(struct platform_device *pdev)
{
struct syscon_led *sled = platform_get_drvdata(pdev);
led_classdev_unregister(&sled->cdev);
/* Turn it off */
regmap_update_bits(sled->map, sled->offset, sled->mask, 0);
return 0;
}
static const struct of_device_id of_syscon_leds_match[] = {
{ .compatible = "register-bit-led", },
{},
};
MODULE_DEVICE_TABLE(of, of_syscon_leds_match);
static struct platform_driver syscon_led_driver = {
.probe = syscon_led_probe,
.remove = syscon_led_remove,
.driver = {
.name = "leds-syscon",
.of_match_table = of_syscon_leds_match,
},
};
module_platform_driver(syscon_led_driver);
|
