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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> |
c971ff18 | 25 | #include <linux/workqueue.h> |
41c42ff5 LF |
26 | |
27 | struct led_pwm_data { | |
28 | struct led_classdev cdev; | |
29 | struct pwm_device *pwm; | |
c971ff18 | 30 | struct work_struct work; |
dcba9105 | 31 | unsigned int active_low; |
41c42ff5 | 32 | unsigned int period; |
c971ff18 FV |
33 | int duty; |
34 | bool can_sleep; | |
41c42ff5 LF |
35 | }; |
36 | ||
0f86815a PU |
37 | struct led_pwm_priv { |
38 | int num_leds; | |
39 | struct led_pwm_data leds[0]; | |
40 | }; | |
41 | ||
c971ff18 FV |
42 | static void __led_pwm_set(struct led_pwm_data *led_dat) |
43 | { | |
44 | int new_duty = led_dat->duty; | |
45 | ||
46 | pwm_config(led_dat->pwm, new_duty, led_dat->period); | |
47 | ||
48 | if (new_duty == 0) | |
49 | pwm_disable(led_dat->pwm); | |
50 | else | |
51 | pwm_enable(led_dat->pwm); | |
52 | } | |
53 | ||
54 | static void led_pwm_work(struct work_struct *work) | |
55 | { | |
56 | struct led_pwm_data *led_dat = | |
57 | container_of(work, struct led_pwm_data, work); | |
58 | ||
59 | __led_pwm_set(led_dat); | |
60 | } | |
61 | ||
41c42ff5 LF |
62 | static void led_pwm_set(struct led_classdev *led_cdev, |
63 | enum led_brightness brightness) | |
64 | { | |
65 | struct led_pwm_data *led_dat = | |
66 | container_of(led_cdev, struct led_pwm_data, cdev); | |
e4590620 | 67 | unsigned int max = led_dat->cdev.max_brightness; |
fc1aee03 | 68 | unsigned long long duty = led_dat->period; |
41c42ff5 | 69 | |
fc1aee03 XL |
70 | duty *= brightness; |
71 | do_div(duty, max); | |
72 | led_dat->duty = duty; | |
c971ff18 FV |
73 | |
74 | if (led_dat->can_sleep) | |
75 | schedule_work(&led_dat->work); | |
76 | else | |
77 | __led_pwm_set(led_dat); | |
41c42ff5 LF |
78 | } |
79 | ||
0f86815a PU |
80 | static inline size_t sizeof_pwm_leds_priv(int num_leds) |
81 | { | |
82 | return sizeof(struct led_pwm_priv) + | |
83 | (sizeof(struct led_pwm_data) * num_leds); | |
84 | } | |
85 | ||
39236901 RK |
86 | static void led_pwm_cleanup(struct led_pwm_priv *priv) |
87 | { | |
88 | while (priv->num_leds--) { | |
89 | led_classdev_unregister(&priv->leds[priv->num_leds].cdev); | |
90 | if (priv->leds[priv->num_leds].can_sleep) | |
91 | cancel_work_sync(&priv->leds[priv->num_leds].work); | |
92 | } | |
93 | } | |
94 | ||
aa1a6d6d PU |
95 | static int led_pwm_create_of(struct platform_device *pdev, |
96 | struct led_pwm_priv *priv) | |
41c42ff5 | 97 | { |
08541cbc | 98 | struct device_node *child; |
aa1a6d6d | 99 | int ret; |
41c42ff5 | 100 | |
33fc9450 | 101 | for_each_child_of_node(pdev->dev.of_node, child) { |
08541cbc | 102 | struct led_pwm_data *led_dat = &priv->leds[priv->num_leds]; |
41c42ff5 | 103 | |
08541cbc PU |
104 | led_dat->cdev.name = of_get_property(child, "label", |
105 | NULL) ? : child->name; | |
106 | ||
107 | led_dat->pwm = devm_of_pwm_get(&pdev->dev, child, NULL); | |
41c42ff5 | 108 | if (IS_ERR(led_dat->pwm)) { |
9ea6cdac | 109 | dev_err(&pdev->dev, "unable to request PWM for %s\n", |
08541cbc | 110 | led_dat->cdev.name); |
aa1a6d6d | 111 | ret = PTR_ERR(led_dat->pwm); |
41c42ff5 LF |
112 | goto err; |
113 | } | |
08541cbc PU |
114 | /* Get the period from PWM core when n*/ |
115 | led_dat->period = pwm_get_period(led_dat->pwm); | |
116 | ||
117 | led_dat->cdev.default_trigger = of_get_property(child, | |
118 | "linux,default-trigger", NULL); | |
119 | of_property_read_u32(child, "max-brightness", | |
120 | &led_dat->cdev.max_brightness); | |
41c42ff5 | 121 | |
41c42ff5 LF |
122 | led_dat->cdev.brightness_set = led_pwm_set; |
123 | led_dat->cdev.brightness = LED_OFF; | |
124 | led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; | |
125 | ||
c971ff18 FV |
126 | led_dat->can_sleep = pwm_can_sleep(led_dat->pwm); |
127 | if (led_dat->can_sleep) | |
128 | INIT_WORK(&led_dat->work, led_pwm_work); | |
129 | ||
41c42ff5 | 130 | ret = led_classdev_register(&pdev->dev, &led_dat->cdev); |
08541cbc PU |
131 | if (ret < 0) { |
132 | dev_err(&pdev->dev, "failed to register for %s\n", | |
133 | led_dat->cdev.name); | |
134 | of_node_put(child); | |
41c42ff5 | 135 | goto err; |
08541cbc PU |
136 | } |
137 | priv->num_leds++; | |
138 | } | |
139 | ||
aa1a6d6d | 140 | return 0; |
08541cbc | 141 | err: |
39236901 | 142 | led_pwm_cleanup(priv); |
08541cbc | 143 | |
aa1a6d6d | 144 | return ret; |
08541cbc PU |
145 | } |
146 | ||
147 | static int led_pwm_probe(struct platform_device *pdev) | |
148 | { | |
87aae1ea | 149 | struct led_pwm_platform_data *pdata = dev_get_platdata(&pdev->dev); |
08541cbc | 150 | struct led_pwm_priv *priv; |
aa1a6d6d PU |
151 | int count, i; |
152 | int ret = 0; | |
153 | ||
154 | if (pdata) | |
155 | count = pdata->num_leds; | |
156 | else | |
157 | count = of_get_child_count(pdev->dev.of_node); | |
158 | ||
159 | if (!count) | |
160 | return -EINVAL; | |
08541cbc | 161 | |
aa1a6d6d PU |
162 | priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count), |
163 | GFP_KERNEL); | |
164 | if (!priv) | |
165 | return -ENOMEM; | |
08541cbc | 166 | |
aa1a6d6d PU |
167 | if (pdata) { |
168 | for (i = 0; i < count; i++) { | |
08541cbc PU |
169 | struct led_pwm *cur_led = &pdata->leds[i]; |
170 | struct led_pwm_data *led_dat = &priv->leds[i]; | |
171 | ||
172 | led_dat->pwm = devm_pwm_get(&pdev->dev, cur_led->name); | |
173 | if (IS_ERR(led_dat->pwm)) { | |
174 | ret = PTR_ERR(led_dat->pwm); | |
175 | dev_err(&pdev->dev, | |
176 | "unable to request PWM for %s\n", | |
177 | cur_led->name); | |
178 | goto err; | |
179 | } | |
180 | ||
181 | led_dat->cdev.name = cur_led->name; | |
182 | led_dat->cdev.default_trigger = cur_led->default_trigger; | |
183 | led_dat->active_low = cur_led->active_low; | |
184 | led_dat->period = cur_led->pwm_period_ns; | |
185 | led_dat->cdev.brightness_set = led_pwm_set; | |
186 | led_dat->cdev.brightness = LED_OFF; | |
187 | led_dat->cdev.max_brightness = cur_led->max_brightness; | |
188 | led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; | |
189 | ||
c971ff18 FV |
190 | led_dat->can_sleep = pwm_can_sleep(led_dat->pwm); |
191 | if (led_dat->can_sleep) | |
192 | INIT_WORK(&led_dat->work, led_pwm_work); | |
193 | ||
08541cbc PU |
194 | ret = led_classdev_register(&pdev->dev, &led_dat->cdev); |
195 | if (ret < 0) | |
196 | goto err; | |
197 | } | |
aa1a6d6d | 198 | priv->num_leds = count; |
08541cbc | 199 | } else { |
aa1a6d6d PU |
200 | ret = led_pwm_create_of(pdev, priv); |
201 | if (ret) | |
202 | return ret; | |
41c42ff5 LF |
203 | } |
204 | ||
0f86815a | 205 | platform_set_drvdata(pdev, priv); |
41c42ff5 LF |
206 | |
207 | return 0; | |
208 | ||
209 | err: | |
39236901 RK |
210 | priv->num_leds = i; |
211 | led_pwm_cleanup(priv); | |
41c42ff5 | 212 | |
41c42ff5 LF |
213 | return ret; |
214 | } | |
215 | ||
678e8a6b | 216 | static int led_pwm_remove(struct platform_device *pdev) |
41c42ff5 | 217 | { |
0f86815a | 218 | struct led_pwm_priv *priv = platform_get_drvdata(pdev); |
41c42ff5 | 219 | |
39236901 | 220 | led_pwm_cleanup(priv); |
41c42ff5 | 221 | |
41c42ff5 LF |
222 | return 0; |
223 | } | |
224 | ||
08541cbc PU |
225 | static const struct of_device_id of_pwm_leds_match[] = { |
226 | { .compatible = "pwm-leds", }, | |
227 | {}, | |
228 | }; | |
229 | MODULE_DEVICE_TABLE(of, of_pwm_leds_match); | |
230 | ||
41c42ff5 LF |
231 | static struct platform_driver led_pwm_driver = { |
232 | .probe = led_pwm_probe, | |
df07cf81 | 233 | .remove = led_pwm_remove, |
41c42ff5 LF |
234 | .driver = { |
235 | .name = "leds_pwm", | |
236 | .owner = THIS_MODULE, | |
1e08f72d | 237 | .of_match_table = of_pwm_leds_match, |
41c42ff5 LF |
238 | }, |
239 | }; | |
240 | ||
892a8843 | 241 | module_platform_driver(led_pwm_driver); |
41c42ff5 LF |
242 | |
243 | MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); | |
244 | MODULE_DESCRIPTION("PWM LED driver for PXA"); | |
245 | MODULE_LICENSE("GPL"); | |
246 | MODULE_ALIAS("platform:leds-pwm"); |