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/fb.h> |
20 | #include <linux/leds.h> | |
21 | #include <linux/err.h> | |
22 | #include <linux/pwm.h> | |
23 | #include <linux/leds_pwm.h> | |
5a0e3ad6 | 24 | #include <linux/slab.h> |
41c42ff5 LF |
25 | |
26 | struct led_pwm_data { | |
27 | struct led_classdev cdev; | |
28 | struct pwm_device *pwm; | |
dcba9105 | 29 | unsigned int active_low; |
41c42ff5 | 30 | unsigned int period; |
c971ff18 FV |
31 | int duty; |
32 | bool can_sleep; | |
41c42ff5 LF |
33 | }; |
34 | ||
0f86815a PU |
35 | struct led_pwm_priv { |
36 | int num_leds; | |
37 | struct led_pwm_data leds[0]; | |
38 | }; | |
39 | ||
c971ff18 FV |
40 | static void __led_pwm_set(struct led_pwm_data *led_dat) |
41 | { | |
42 | int new_duty = led_dat->duty; | |
43 | ||
44 | pwm_config(led_dat->pwm, new_duty, led_dat->period); | |
45 | ||
46 | if (new_duty == 0) | |
47 | pwm_disable(led_dat->pwm); | |
48 | else | |
49 | pwm_enable(led_dat->pwm); | |
50 | } | |
51 | ||
41c42ff5 LF |
52 | static void led_pwm_set(struct led_classdev *led_cdev, |
53 | enum led_brightness brightness) | |
54 | { | |
55 | struct led_pwm_data *led_dat = | |
56 | container_of(led_cdev, struct led_pwm_data, cdev); | |
e4590620 | 57 | unsigned int max = led_dat->cdev.max_brightness; |
fc1aee03 | 58 | unsigned long long duty = led_dat->period; |
41c42ff5 | 59 | |
fc1aee03 XL |
60 | duty *= brightness; |
61 | do_div(duty, max); | |
d19a8a70 RK |
62 | |
63 | if (led_dat->active_low) | |
64 | duty = led_dat->period - duty; | |
65 | ||
fc1aee03 | 66 | led_dat->duty = duty; |
c971ff18 | 67 | |
9aa07625 JA |
68 | __led_pwm_set(led_dat); |
69 | } | |
70 | ||
71 | static int led_pwm_set_blocking(struct led_classdev *led_cdev, | |
72 | enum led_brightness brightness) | |
73 | { | |
74 | led_pwm_set(led_cdev, brightness); | |
75 | return 0; | |
41c42ff5 LF |
76 | } |
77 | ||
0f86815a PU |
78 | static inline size_t sizeof_pwm_leds_priv(int num_leds) |
79 | { | |
80 | return sizeof(struct led_pwm_priv) + | |
81 | (sizeof(struct led_pwm_data) * num_leds); | |
82 | } | |
83 | ||
39236901 RK |
84 | static void led_pwm_cleanup(struct led_pwm_priv *priv) |
85 | { | |
9aa07625 | 86 | while (priv->num_leds--) |
39236901 | 87 | led_classdev_unregister(&priv->leds[priv->num_leds].cdev); |
39236901 RK |
88 | } |
89 | ||
5f7b03dc | 90 | static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv, |
b795e6d9 | 91 | struct led_pwm *led, struct device_node *child) |
41c42ff5 | 92 | { |
5f7b03dc | 93 | struct led_pwm_data *led_data = &priv->leds[priv->num_leds]; |
aa1a6d6d | 94 | int ret; |
41c42ff5 | 95 | |
5f7b03dc | 96 | led_data->active_low = led->active_low; |
5f7b03dc RK |
97 | led_data->cdev.name = led->name; |
98 | led_data->cdev.default_trigger = led->default_trigger; | |
5f7b03dc RK |
99 | led_data->cdev.brightness = LED_OFF; |
100 | led_data->cdev.max_brightness = led->max_brightness; | |
101 | led_data->cdev.flags = LED_CORE_SUSPENDRESUME; | |
41c42ff5 | 102 | |
b795e6d9 RK |
103 | if (child) |
104 | led_data->pwm = devm_of_pwm_get(dev, child, NULL); | |
105 | else | |
106 | led_data->pwm = devm_pwm_get(dev, led->name); | |
5f7b03dc RK |
107 | if (IS_ERR(led_data->pwm)) { |
108 | ret = PTR_ERR(led_data->pwm); | |
109 | dev_err(dev, "unable to request PWM for %s: %d\n", | |
110 | led->name, ret); | |
111 | return ret; | |
112 | } | |
08541cbc | 113 | |
5f7b03dc | 114 | led_data->can_sleep = pwm_can_sleep(led_data->pwm); |
9aa07625 JA |
115 | if (!led_data->can_sleep) |
116 | led_data->cdev.brightness_set = led_pwm_set; | |
117 | else | |
118 | led_data->cdev.brightness_set_blocking = led_pwm_set_blocking; | |
41c42ff5 | 119 | |
7c574cf6 LT |
120 | led_data->period = pwm_get_period(led_data->pwm); |
121 | if (!led_data->period && (led->pwm_period_ns > 0)) | |
122 | led_data->period = led->pwm_period_ns; | |
41c42ff5 | 123 | |
5f7b03dc RK |
124 | ret = led_classdev_register(dev, &led_data->cdev); |
125 | if (ret == 0) { | |
126 | priv->num_leds++; | |
f1670336 | 127 | led_pwm_set(&led_data->cdev, led_data->cdev.brightness); |
5f7b03dc RK |
128 | } else { |
129 | dev_err(dev, "failed to register PWM led for %s: %d\n", | |
130 | led->name, ret); | |
131 | } | |
132 | ||
133 | return ret; | |
134 | } | |
c971ff18 | 135 | |
b795e6d9 | 136 | static int led_pwm_create_of(struct device *dev, struct led_pwm_priv *priv) |
41c42ff5 | 137 | { |
08541cbc | 138 | struct device_node *child; |
b795e6d9 RK |
139 | struct led_pwm led; |
140 | int ret = 0; | |
41c42ff5 | 141 | |
b795e6d9 | 142 | memset(&led, 0, sizeof(led)); |
08541cbc | 143 | |
b795e6d9 RK |
144 | for_each_child_of_node(dev->of_node, child) { |
145 | led.name = of_get_property(child, "label", NULL) ? : | |
146 | child->name; | |
08541cbc | 147 | |
b795e6d9 | 148 | led.default_trigger = of_get_property(child, |
08541cbc | 149 | "linux,default-trigger", NULL); |
b0571e7e | 150 | led.active_low = of_property_read_bool(child, "active-low"); |
08541cbc | 151 | of_property_read_u32(child, "max-brightness", |
b795e6d9 | 152 | &led.max_brightness); |
c971ff18 | 153 | |
b795e6d9 RK |
154 | ret = led_pwm_add(dev, priv, &led, child); |
155 | if (ret) { | |
08541cbc | 156 | of_node_put(child); |
b795e6d9 | 157 | break; |
08541cbc | 158 | } |
08541cbc PU |
159 | } |
160 | ||
aa1a6d6d | 161 | return ret; |
08541cbc PU |
162 | } |
163 | ||
164 | static int led_pwm_probe(struct platform_device *pdev) | |
165 | { | |
87aae1ea | 166 | struct led_pwm_platform_data *pdata = dev_get_platdata(&pdev->dev); |
08541cbc | 167 | struct led_pwm_priv *priv; |
aa1a6d6d PU |
168 | int count, i; |
169 | int ret = 0; | |
170 | ||
171 | if (pdata) | |
172 | count = pdata->num_leds; | |
173 | else | |
174 | count = of_get_child_count(pdev->dev.of_node); | |
175 | ||
176 | if (!count) | |
177 | return -EINVAL; | |
08541cbc | 178 | |
aa1a6d6d PU |
179 | priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count), |
180 | GFP_KERNEL); | |
181 | if (!priv) | |
182 | return -ENOMEM; | |
08541cbc | 183 | |
aa1a6d6d PU |
184 | if (pdata) { |
185 | for (i = 0; i < count; i++) { | |
b795e6d9 RK |
186 | ret = led_pwm_add(&pdev->dev, priv, &pdata->leds[i], |
187 | NULL); | |
5f7b03dc RK |
188 | if (ret) |
189 | break; | |
08541cbc | 190 | } |
08541cbc | 191 | } else { |
b795e6d9 | 192 | ret = led_pwm_create_of(&pdev->dev, priv); |
5f7b03dc RK |
193 | } |
194 | ||
195 | if (ret) { | |
196 | led_pwm_cleanup(priv); | |
197 | return ret; | |
41c42ff5 LF |
198 | } |
199 | ||
0f86815a | 200 | platform_set_drvdata(pdev, priv); |
41c42ff5 LF |
201 | |
202 | return 0; | |
41c42ff5 LF |
203 | } |
204 | ||
678e8a6b | 205 | static int led_pwm_remove(struct platform_device *pdev) |
41c42ff5 | 206 | { |
0f86815a | 207 | struct led_pwm_priv *priv = platform_get_drvdata(pdev); |
41c42ff5 | 208 | |
39236901 | 209 | led_pwm_cleanup(priv); |
41c42ff5 | 210 | |
41c42ff5 LF |
211 | return 0; |
212 | } | |
213 | ||
08541cbc PU |
214 | static const struct of_device_id of_pwm_leds_match[] = { |
215 | { .compatible = "pwm-leds", }, | |
216 | {}, | |
217 | }; | |
218 | MODULE_DEVICE_TABLE(of, of_pwm_leds_match); | |
219 | ||
41c42ff5 LF |
220 | static struct platform_driver led_pwm_driver = { |
221 | .probe = led_pwm_probe, | |
df07cf81 | 222 | .remove = led_pwm_remove, |
41c42ff5 LF |
223 | .driver = { |
224 | .name = "leds_pwm", | |
1e08f72d | 225 | .of_match_table = of_pwm_leds_match, |
41c42ff5 LF |
226 | }, |
227 | }; | |
228 | ||
892a8843 | 229 | module_platform_driver(led_pwm_driver); |
41c42ff5 LF |
230 | |
231 | MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); | |
49651c6c UKK |
232 | MODULE_DESCRIPTION("generic PWM LED driver"); |
233 | MODULE_LICENSE("GPL v2"); | |
41c42ff5 | 234 | MODULE_ALIAS("platform:leds-pwm"); |