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
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* PWM-based multi-color LED control
*
* Copyright 2022 Sven Schwermer <sven.schwermer@disruptive-technologies.com>
*/
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/led-class-multicolor.h>
#include <linux/leds.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/pwm.h>
struct pwm_led {
struct pwm_device *pwm;
struct pwm_state state;
};
struct pwm_mc_led {
struct led_classdev_mc mc_cdev;
struct mutex lock;
struct pwm_led leds[];
};
static int led_pwm_mc_set(struct led_classdev *cdev,
enum led_brightness brightness)
{
struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
struct pwm_mc_led *priv = container_of(mc_cdev, struct pwm_mc_led, mc_cdev);
unsigned long long duty;
int ret = 0;
int i;
led_mc_calc_color_components(mc_cdev, brightness);
mutex_lock(&priv->lock);
for (i = 0; i < mc_cdev->num_colors; i++) {
duty = priv->leds[i].state.period;
duty *= mc_cdev->subled_info[i].brightness;
do_div(duty, cdev->max_brightness);
priv->leds[i].state.duty_cycle = duty;
priv->leds[i].state.enabled = duty > 0;
ret = pwm_apply_state(priv->leds[i].pwm,
&priv->leds[i].state);
if (ret)
break;
}
mutex_unlock(&priv->lock);
return ret;
}
static int iterate_subleds(struct device *dev, struct pwm_mc_led *priv,
struct fwnode_handle *mcnode)
{
struct mc_subled *subled = priv->mc_cdev.subled_info;
struct fwnode_handle *fwnode;
struct pwm_led *pwmled;
u32 color;
int ret;
/* iterate over the nodes inside the multi-led node */
fwnode_for_each_child_node(mcnode, fwnode) {
pwmled = &priv->leds[priv->mc_cdev.num_colors];
pwmled->pwm = devm_fwnode_pwm_get(dev, fwnode, NULL);
if (IS_ERR(pwmled->pwm)) {
ret = dev_err_probe(dev, PTR_ERR(pwmled->pwm), "unable to request PWM\n");
goto release_fwnode;
}
pwm_init_state(pwmled->pwm, &pwmled->state);
ret = fwnode_property_read_u32(fwnode, "color", &color);
if (ret) {
dev_err(dev, "cannot read color: %d\n", ret);
goto release_fwnode;
}
subled[priv->mc_cdev.num_colors].color_index = color;
priv->mc_cdev.num_colors++;
}
return 0;
release_fwnode:
fwnode_handle_put(fwnode);
return ret;
}
static int led_pwm_mc_probe(struct platform_device *pdev)
{
struct fwnode_handle *mcnode, *fwnode;
struct led_init_data init_data = {};
struct led_classdev *cdev;
struct mc_subled *subled;
struct pwm_mc_led *priv;
int count = 0;
int ret = 0;
mcnode = device_get_named_child_node(&pdev->dev, "multi-led");
if (!mcnode)
return dev_err_probe(&pdev->dev, -ENODEV,
"expected multi-led node\n");
/* count the nodes inside the multi-led node */
fwnode_for_each_child_node(mcnode, fwnode)
count++;
priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, count),
GFP_KERNEL);
if (!priv) {
ret = -ENOMEM;
goto release_mcnode;
}
mutex_init(&priv->lock);
subled = devm_kcalloc(&pdev->dev, count, sizeof(*subled), GFP_KERNEL);
if (!subled) {
ret = -ENOMEM;
goto release_mcnode;
}
priv->mc_cdev.subled_info = subled;
/* init the multicolor's LED class device */
cdev = &priv->mc_cdev.led_cdev;
fwnode_property_read_u32(mcnode, "max-brightness",
&cdev->max_brightness);
cdev->flags = LED_CORE_SUSPENDRESUME;
cdev->brightness_set_blocking = led_pwm_mc_set;
ret = iterate_subleds(&pdev->dev, priv, mcnode);
if (ret)
goto release_mcnode;
init_data.fwnode = mcnode;
ret = devm_led_classdev_multicolor_register_ext(&pdev->dev,
&priv->mc_cdev,
&init_data);
if (ret) {
dev_err(&pdev->dev,
"failed to register multicolor PWM led for %s: %d\n",
cdev->name, ret);
goto release_mcnode;
}
ret = led_pwm_mc_set(cdev, cdev->brightness);
if (ret)
return dev_err_probe(&pdev->dev, ret,
"failed to set led PWM value for %s: %d",
cdev->name, ret);
platform_set_drvdata(pdev, priv);
return 0;
release_mcnode:
fwnode_handle_put(mcnode);
return ret;
}
static const struct of_device_id of_pwm_leds_mc_match[] = {
{ .compatible = "pwm-leds-multicolor", },
{}
};
MODULE_DEVICE_TABLE(of, of_pwm_leds_mc_match);
static struct platform_driver led_pwm_mc_driver = {
.probe = led_pwm_mc_probe,
.driver = {
.name = "leds_pwm_multicolor",
.of_match_table = of_pwm_leds_mc_match,
},
};
module_platform_driver(led_pwm_mc_driver);
MODULE_AUTHOR("Sven Schwermer <sven.schwermer@disruptive-technologies.com>");
MODULE_DESCRIPTION("multi-color PWM LED driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:leds-pwm-multicolor");
|
