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Commit | Line | Data |
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41c42ff5 LF |
1 | /* |
2 | * linux/drivers/leds-pwm.c | |
3 | * | |
4 | * simple PWM based LED control | |
5 | * | |
6 | * Copyright 2009 Luotao Fu @ Pengutronix (l.fu@pengutronix.de) | |
7 | * | |
8 | * based on leds-gpio.c by Raphael Assenat <raph@8d.com> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | */ | |
14 | ||
15 | #include <linux/module.h> | |
16 | #include <linux/kernel.h> | |
41c42ff5 | 17 | #include <linux/platform_device.h> |
08541cbc | 18 | #include <linux/of_platform.h> |
41c42ff5 LF |
19 | #include <linux/leds.h> |
20 | #include <linux/err.h> | |
21 | #include <linux/pwm.h> | |
22 | #include <linux/leds_pwm.h> | |
5a0e3ad6 | 23 | #include <linux/slab.h> |
41c42ff5 LF |
24 | |
25 | struct led_pwm_data { | |
26 | struct led_classdev cdev; | |
27 | struct pwm_device *pwm; | |
dcba9105 | 28 | unsigned int active_low; |
41c42ff5 | 29 | unsigned int period; |
c971ff18 | 30 | int duty; |
41c42ff5 LF |
31 | }; |
32 | ||
0f86815a PU |
33 | struct led_pwm_priv { |
34 | int num_leds; | |
35 | struct led_pwm_data leds[0]; | |
36 | }; | |
37 | ||
c971ff18 FV |
38 | static void __led_pwm_set(struct led_pwm_data *led_dat) |
39 | { | |
40 | int new_duty = led_dat->duty; | |
41 | ||
42 | pwm_config(led_dat->pwm, new_duty, led_dat->period); | |
43 | ||
44 | if (new_duty == 0) | |
45 | pwm_disable(led_dat->pwm); | |
46 | else | |
47 | pwm_enable(led_dat->pwm); | |
48 | } | |
49 | ||
247bde13 TR |
50 | static int led_pwm_set(struct led_classdev *led_cdev, |
51 | enum led_brightness brightness) | |
41c42ff5 LF |
52 | { |
53 | struct led_pwm_data *led_dat = | |
54 | container_of(led_cdev, struct led_pwm_data, cdev); | |
e4590620 | 55 | unsigned int max = led_dat->cdev.max_brightness; |
fc1aee03 | 56 | unsigned long long duty = led_dat->period; |
41c42ff5 | 57 | |
fc1aee03 XL |
58 | duty *= brightness; |
59 | do_div(duty, max); | |
d19a8a70 RK |
60 | |
61 | if (led_dat->active_low) | |
62 | duty = led_dat->period - duty; | |
63 | ||
fc1aee03 | 64 | led_dat->duty = duty; |
c971ff18 | 65 | |
9aa07625 | 66 | __led_pwm_set(led_dat); |
9aa07625 | 67 | |
9aa07625 | 68 | return 0; |
41c42ff5 LF |
69 | } |
70 | ||
0f86815a PU |
71 | static inline size_t sizeof_pwm_leds_priv(int num_leds) |
72 | { | |
73 | return sizeof(struct led_pwm_priv) + | |
74 | (sizeof(struct led_pwm_data) * num_leds); | |
75 | } | |
76 | ||
5f7b03dc | 77 | static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv, |
b795e6d9 | 78 | struct led_pwm *led, struct device_node *child) |
41c42ff5 | 79 | { |
5f7b03dc | 80 | struct led_pwm_data *led_data = &priv->leds[priv->num_leds]; |
1b50673d | 81 | struct pwm_args pargs; |
aa1a6d6d | 82 | int ret; |
41c42ff5 | 83 | |
5f7b03dc | 84 | led_data->active_low = led->active_low; |
5f7b03dc RK |
85 | led_data->cdev.name = led->name; |
86 | led_data->cdev.default_trigger = led->default_trigger; | |
5f7b03dc RK |
87 | led_data->cdev.brightness = LED_OFF; |
88 | led_data->cdev.max_brightness = led->max_brightness; | |
89 | led_data->cdev.flags = LED_CORE_SUSPENDRESUME; | |
41c42ff5 | 90 | |
b795e6d9 RK |
91 | if (child) |
92 | led_data->pwm = devm_of_pwm_get(dev, child, NULL); | |
93 | else | |
94 | led_data->pwm = devm_pwm_get(dev, led->name); | |
5f7b03dc RK |
95 | if (IS_ERR(led_data->pwm)) { |
96 | ret = PTR_ERR(led_data->pwm); | |
9aec3037 JB |
97 | if (ret != -EPROBE_DEFER) |
98 | dev_err(dev, "unable to request PWM for %s: %d\n", | |
99 | led->name, ret); | |
5f7b03dc RK |
100 | return ret; |
101 | } | |
08541cbc | 102 | |
247bde13 | 103 | led_data->cdev.brightness_set_blocking = led_pwm_set; |
41c42ff5 | 104 | |
1b50673d BB |
105 | /* |
106 | * FIXME: pwm_apply_args() should be removed when switching to the | |
107 | * atomic PWM API. | |
108 | */ | |
109 | pwm_apply_args(led_data->pwm); | |
110 | ||
111 | pwm_get_args(led_data->pwm, &pargs); | |
112 | ||
113 | led_data->period = pargs.period; | |
7c574cf6 LT |
114 | if (!led_data->period && (led->pwm_period_ns > 0)) |
115 | led_data->period = led->pwm_period_ns; | |
41c42ff5 | 116 | |
e5a0436d | 117 | ret = devm_led_classdev_register(dev, &led_data->cdev); |
5f7b03dc RK |
118 | if (ret == 0) { |
119 | priv->num_leds++; | |
f1670336 | 120 | led_pwm_set(&led_data->cdev, led_data->cdev.brightness); |
5f7b03dc RK |
121 | } else { |
122 | dev_err(dev, "failed to register PWM led for %s: %d\n", | |
123 | led->name, ret); | |
124 | } | |
125 | ||
126 | return ret; | |
127 | } | |
c971ff18 | 128 | |
b795e6d9 | 129 | static int led_pwm_create_of(struct device *dev, struct led_pwm_priv *priv) |
41c42ff5 | 130 | { |
08541cbc | 131 | struct device_node *child; |
b795e6d9 RK |
132 | struct led_pwm led; |
133 | int ret = 0; | |
41c42ff5 | 134 | |
b795e6d9 | 135 | memset(&led, 0, sizeof(led)); |
08541cbc | 136 | |
b795e6d9 RK |
137 | for_each_child_of_node(dev->of_node, child) { |
138 | led.name = of_get_property(child, "label", NULL) ? : | |
139 | child->name; | |
08541cbc | 140 | |
b795e6d9 | 141 | led.default_trigger = of_get_property(child, |
08541cbc | 142 | "linux,default-trigger", NULL); |
b0571e7e | 143 | led.active_low = of_property_read_bool(child, "active-low"); |
08541cbc | 144 | of_property_read_u32(child, "max-brightness", |
b795e6d9 | 145 | &led.max_brightness); |
c971ff18 | 146 | |
b795e6d9 RK |
147 | ret = led_pwm_add(dev, priv, &led, child); |
148 | if (ret) { | |
08541cbc | 149 | of_node_put(child); |
b795e6d9 | 150 | break; |
08541cbc | 151 | } |
08541cbc PU |
152 | } |
153 | ||
aa1a6d6d | 154 | return ret; |
08541cbc PU |
155 | } |
156 | ||
157 | static int led_pwm_probe(struct platform_device *pdev) | |
158 | { | |
87aae1ea | 159 | struct led_pwm_platform_data *pdata = dev_get_platdata(&pdev->dev); |
08541cbc | 160 | struct led_pwm_priv *priv; |
aa1a6d6d PU |
161 | int count, i; |
162 | int ret = 0; | |
163 | ||
164 | if (pdata) | |
165 | count = pdata->num_leds; | |
166 | else | |
167 | count = of_get_child_count(pdev->dev.of_node); | |
168 | ||
169 | if (!count) | |
170 | return -EINVAL; | |
08541cbc | 171 | |
aa1a6d6d PU |
172 | priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count), |
173 | GFP_KERNEL); | |
174 | if (!priv) | |
175 | return -ENOMEM; | |
08541cbc | 176 | |
aa1a6d6d PU |
177 | if (pdata) { |
178 | for (i = 0; i < count; i++) { | |
b795e6d9 RK |
179 | ret = led_pwm_add(&pdev->dev, priv, &pdata->leds[i], |
180 | NULL); | |
5f7b03dc RK |
181 | if (ret) |
182 | break; | |
08541cbc | 183 | } |
08541cbc | 184 | } else { |
b795e6d9 | 185 | ret = led_pwm_create_of(&pdev->dev, priv); |
5f7b03dc RK |
186 | } |
187 | ||
e5a0436d | 188 | if (ret) |
5f7b03dc | 189 | return ret; |
41c42ff5 | 190 | |
0f86815a | 191 | platform_set_drvdata(pdev, priv); |
41c42ff5 LF |
192 | |
193 | return 0; | |
41c42ff5 LF |
194 | } |
195 | ||
08541cbc PU |
196 | static const struct of_device_id of_pwm_leds_match[] = { |
197 | { .compatible = "pwm-leds", }, | |
198 | {}, | |
199 | }; | |
200 | MODULE_DEVICE_TABLE(of, of_pwm_leds_match); | |
201 | ||
41c42ff5 LF |
202 | static struct platform_driver led_pwm_driver = { |
203 | .probe = led_pwm_probe, | |
41c42ff5 LF |
204 | .driver = { |
205 | .name = "leds_pwm", | |
1e08f72d | 206 | .of_match_table = of_pwm_leds_match, |
41c42ff5 LF |
207 | }, |
208 | }; | |
209 | ||
892a8843 | 210 | module_platform_driver(led_pwm_driver); |
41c42ff5 LF |
211 | |
212 | MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); | |
49651c6c UKK |
213 | MODULE_DESCRIPTION("generic PWM LED driver"); |
214 | MODULE_LICENSE("GPL v2"); | |
41c42ff5 | 215 | MODULE_ALIAS("platform:leds-pwm"); |