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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> | |
17 | #include <linux/init.h> | |
18 | #include <linux/platform_device.h> | |
08541cbc | 19 | #include <linux/of_platform.h> |
41c42ff5 LF |
20 | #include <linux/fb.h> |
21 | #include <linux/leds.h> | |
22 | #include <linux/err.h> | |
23 | #include <linux/pwm.h> | |
24 | #include <linux/leds_pwm.h> | |
5a0e3ad6 | 25 | #include <linux/slab.h> |
c971ff18 | 26 | #include <linux/workqueue.h> |
41c42ff5 LF |
27 | |
28 | struct led_pwm_data { | |
29 | struct led_classdev cdev; | |
30 | struct pwm_device *pwm; | |
c971ff18 | 31 | struct work_struct work; |
dcba9105 | 32 | unsigned int active_low; |
41c42ff5 | 33 | unsigned int period; |
c971ff18 FV |
34 | int duty; |
35 | bool can_sleep; | |
41c42ff5 LF |
36 | }; |
37 | ||
0f86815a PU |
38 | struct led_pwm_priv { |
39 | int num_leds; | |
40 | struct led_pwm_data leds[0]; | |
41 | }; | |
42 | ||
c971ff18 FV |
43 | static void __led_pwm_set(struct led_pwm_data *led_dat) |
44 | { | |
45 | int new_duty = led_dat->duty; | |
46 | ||
47 | pwm_config(led_dat->pwm, new_duty, led_dat->period); | |
48 | ||
49 | if (new_duty == 0) | |
50 | pwm_disable(led_dat->pwm); | |
51 | else | |
52 | pwm_enable(led_dat->pwm); | |
53 | } | |
54 | ||
55 | static void led_pwm_work(struct work_struct *work) | |
56 | { | |
57 | struct led_pwm_data *led_dat = | |
58 | container_of(work, struct led_pwm_data, work); | |
59 | ||
60 | __led_pwm_set(led_dat); | |
61 | } | |
62 | ||
41c42ff5 LF |
63 | static void led_pwm_set(struct led_classdev *led_cdev, |
64 | enum led_brightness brightness) | |
65 | { | |
66 | struct led_pwm_data *led_dat = | |
67 | container_of(led_cdev, struct led_pwm_data, cdev); | |
e4590620 | 68 | unsigned int max = led_dat->cdev.max_brightness; |
41c42ff5 LF |
69 | unsigned int period = led_dat->period; |
70 | ||
c971ff18 FV |
71 | led_dat->duty = brightness * period / max; |
72 | ||
73 | if (led_dat->can_sleep) | |
74 | schedule_work(&led_dat->work); | |
75 | else | |
76 | __led_pwm_set(led_dat); | |
41c42ff5 LF |
77 | } |
78 | ||
0f86815a PU |
79 | static inline size_t sizeof_pwm_leds_priv(int num_leds) |
80 | { | |
81 | return sizeof(struct led_pwm_priv) + | |
82 | (sizeof(struct led_pwm_data) * num_leds); | |
83 | } | |
84 | ||
aa1a6d6d PU |
85 | static int led_pwm_create_of(struct platform_device *pdev, |
86 | struct led_pwm_priv *priv) | |
41c42ff5 | 87 | { |
08541cbc PU |
88 | struct device_node *node = pdev->dev.of_node; |
89 | struct device_node *child; | |
aa1a6d6d | 90 | int ret; |
41c42ff5 | 91 | |
08541cbc PU |
92 | for_each_child_of_node(node, child) { |
93 | struct led_pwm_data *led_dat = &priv->leds[priv->num_leds]; | |
41c42ff5 | 94 | |
08541cbc PU |
95 | led_dat->cdev.name = of_get_property(child, "label", |
96 | NULL) ? : child->name; | |
97 | ||
98 | led_dat->pwm = devm_of_pwm_get(&pdev->dev, child, NULL); | |
41c42ff5 | 99 | if (IS_ERR(led_dat->pwm)) { |
9ea6cdac | 100 | dev_err(&pdev->dev, "unable to request PWM for %s\n", |
08541cbc | 101 | led_dat->cdev.name); |
aa1a6d6d | 102 | ret = PTR_ERR(led_dat->pwm); |
41c42ff5 LF |
103 | goto err; |
104 | } | |
08541cbc PU |
105 | /* Get the period from PWM core when n*/ |
106 | led_dat->period = pwm_get_period(led_dat->pwm); | |
107 | ||
108 | led_dat->cdev.default_trigger = of_get_property(child, | |
109 | "linux,default-trigger", NULL); | |
110 | of_property_read_u32(child, "max-brightness", | |
111 | &led_dat->cdev.max_brightness); | |
41c42ff5 | 112 | |
41c42ff5 LF |
113 | led_dat->cdev.brightness_set = led_pwm_set; |
114 | led_dat->cdev.brightness = LED_OFF; | |
115 | led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; | |
116 | ||
c971ff18 FV |
117 | led_dat->can_sleep = pwm_can_sleep(led_dat->pwm); |
118 | if (led_dat->can_sleep) | |
119 | INIT_WORK(&led_dat->work, led_pwm_work); | |
120 | ||
41c42ff5 | 121 | ret = led_classdev_register(&pdev->dev, &led_dat->cdev); |
08541cbc PU |
122 | if (ret < 0) { |
123 | dev_err(&pdev->dev, "failed to register for %s\n", | |
124 | led_dat->cdev.name); | |
125 | of_node_put(child); | |
41c42ff5 | 126 | goto err; |
08541cbc PU |
127 | } |
128 | priv->num_leds++; | |
129 | } | |
130 | ||
aa1a6d6d | 131 | return 0; |
08541cbc PU |
132 | err: |
133 | while (priv->num_leds--) | |
134 | led_classdev_unregister(&priv->leds[priv->num_leds].cdev); | |
135 | ||
aa1a6d6d | 136 | return ret; |
08541cbc PU |
137 | } |
138 | ||
139 | static int led_pwm_probe(struct platform_device *pdev) | |
140 | { | |
87aae1ea | 141 | struct led_pwm_platform_data *pdata = dev_get_platdata(&pdev->dev); |
08541cbc | 142 | struct led_pwm_priv *priv; |
aa1a6d6d PU |
143 | int count, i; |
144 | int ret = 0; | |
145 | ||
146 | if (pdata) | |
147 | count = pdata->num_leds; | |
148 | else | |
149 | count = of_get_child_count(pdev->dev.of_node); | |
150 | ||
151 | if (!count) | |
152 | return -EINVAL; | |
08541cbc | 153 | |
aa1a6d6d PU |
154 | priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count), |
155 | GFP_KERNEL); | |
156 | if (!priv) | |
157 | return -ENOMEM; | |
08541cbc | 158 | |
aa1a6d6d PU |
159 | if (pdata) { |
160 | for (i = 0; i < count; i++) { | |
08541cbc PU |
161 | struct led_pwm *cur_led = &pdata->leds[i]; |
162 | struct led_pwm_data *led_dat = &priv->leds[i]; | |
163 | ||
164 | led_dat->pwm = devm_pwm_get(&pdev->dev, cur_led->name); | |
165 | if (IS_ERR(led_dat->pwm)) { | |
166 | ret = PTR_ERR(led_dat->pwm); | |
167 | dev_err(&pdev->dev, | |
168 | "unable to request PWM for %s\n", | |
169 | cur_led->name); | |
170 | goto err; | |
171 | } | |
172 | ||
173 | led_dat->cdev.name = cur_led->name; | |
174 | led_dat->cdev.default_trigger = cur_led->default_trigger; | |
175 | led_dat->active_low = cur_led->active_low; | |
176 | led_dat->period = cur_led->pwm_period_ns; | |
177 | led_dat->cdev.brightness_set = led_pwm_set; | |
178 | led_dat->cdev.brightness = LED_OFF; | |
179 | led_dat->cdev.max_brightness = cur_led->max_brightness; | |
180 | led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; | |
181 | ||
c971ff18 FV |
182 | led_dat->can_sleep = pwm_can_sleep(led_dat->pwm); |
183 | if (led_dat->can_sleep) | |
184 | INIT_WORK(&led_dat->work, led_pwm_work); | |
185 | ||
08541cbc PU |
186 | ret = led_classdev_register(&pdev->dev, &led_dat->cdev); |
187 | if (ret < 0) | |
188 | goto err; | |
189 | } | |
aa1a6d6d | 190 | priv->num_leds = count; |
08541cbc | 191 | } else { |
aa1a6d6d PU |
192 | ret = led_pwm_create_of(pdev, priv); |
193 | if (ret) | |
194 | return ret; | |
41c42ff5 LF |
195 | } |
196 | ||
0f86815a | 197 | platform_set_drvdata(pdev, priv); |
41c42ff5 LF |
198 | |
199 | return 0; | |
200 | ||
201 | err: | |
8a66a579 PU |
202 | while (i--) |
203 | led_classdev_unregister(&priv->leds[i].cdev); | |
41c42ff5 | 204 | |
41c42ff5 LF |
205 | return ret; |
206 | } | |
207 | ||
678e8a6b | 208 | static int led_pwm_remove(struct platform_device *pdev) |
41c42ff5 | 209 | { |
0f86815a | 210 | struct led_pwm_priv *priv = platform_get_drvdata(pdev); |
41c42ff5 | 211 | int i; |
41c42ff5 | 212 | |
c971ff18 | 213 | for (i = 0; i < priv->num_leds; i++) { |
0f86815a | 214 | led_classdev_unregister(&priv->leds[i].cdev); |
c971ff18 FV |
215 | if (priv->leds[i].can_sleep) |
216 | cancel_work_sync(&priv->leds[i].work); | |
217 | } | |
41c42ff5 | 218 | |
41c42ff5 LF |
219 | return 0; |
220 | } | |
221 | ||
08541cbc PU |
222 | static const struct of_device_id of_pwm_leds_match[] = { |
223 | { .compatible = "pwm-leds", }, | |
224 | {}, | |
225 | }; | |
226 | MODULE_DEVICE_TABLE(of, of_pwm_leds_match); | |
227 | ||
41c42ff5 LF |
228 | static struct platform_driver led_pwm_driver = { |
229 | .probe = led_pwm_probe, | |
df07cf81 | 230 | .remove = led_pwm_remove, |
41c42ff5 LF |
231 | .driver = { |
232 | .name = "leds_pwm", | |
233 | .owner = THIS_MODULE, | |
1e08f72d | 234 | .of_match_table = of_pwm_leds_match, |
41c42ff5 LF |
235 | }, |
236 | }; | |
237 | ||
892a8843 | 238 | module_platform_driver(led_pwm_driver); |
41c42ff5 LF |
239 | |
240 | MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); | |
241 | MODULE_DESCRIPTION("PWM LED driver for PXA"); | |
242 | MODULE_LICENSE("GPL"); | |
243 | MODULE_ALIAS("platform:leds-pwm"); |