ACPI: Revert conflicting workaround for BIOS w/ mangled PRT entries
[linux-2.6] / drivers / leds / leds-pwm.c
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>
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>
24
25 struct led_pwm_data {
26         struct led_classdev     cdev;
27         struct pwm_device       *pwm;
28         unsigned int            active_low;
29         unsigned int            period;
30         unsigned int            max_brightness;
31 };
32
33 static void led_pwm_set(struct led_classdev *led_cdev,
34         enum led_brightness brightness)
35 {
36         struct led_pwm_data *led_dat =
37                 container_of(led_cdev, struct led_pwm_data, cdev);
38         unsigned int max = led_dat->max_brightness;
39         unsigned int period =  led_dat->period;
40
41         if (brightness == 0) {
42                 pwm_config(led_dat->pwm, 0, period);
43                 pwm_disable(led_dat->pwm);
44         } else {
45                 pwm_config(led_dat->pwm, brightness * period / max, period);
46                 pwm_enable(led_dat->pwm);
47         }
48 }
49
50 static int led_pwm_probe(struct platform_device *pdev)
51 {
52         struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
53         struct led_pwm *cur_led;
54         struct led_pwm_data *leds_data, *led_dat;
55         int i, ret = 0;
56
57         if (!pdata)
58                 return -EBUSY;
59
60         leds_data = kzalloc(sizeof(struct led_pwm_data) * pdata->num_leds,
61                                 GFP_KERNEL);
62         if (!leds_data)
63                 return -ENOMEM;
64
65         for (i = 0; i < pdata->num_leds; i++) {
66                 cur_led = &pdata->leds[i];
67                 led_dat = &leds_data[i];
68
69                 led_dat->pwm = pwm_request(cur_led->pwm_id,
70                                 cur_led->name);
71                 if (IS_ERR(led_dat->pwm)) {
72                         dev_err(&pdev->dev, "unable to request PWM %d\n",
73                                         cur_led->pwm_id);
74                         goto err;
75                 }
76
77                 led_dat->cdev.name = cur_led->name;
78                 led_dat->cdev.default_trigger = cur_led->default_trigger;
79                 led_dat->active_low = cur_led->active_low;
80                 led_dat->max_brightness = cur_led->max_brightness;
81                 led_dat->period = cur_led->pwm_period_ns;
82                 led_dat->cdev.brightness_set = led_pwm_set;
83                 led_dat->cdev.brightness = LED_OFF;
84                 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
85
86                 ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
87                 if (ret < 0) {
88                         pwm_free(led_dat->pwm);
89                         goto err;
90                 }
91         }
92
93         platform_set_drvdata(pdev, leds_data);
94
95         return 0;
96
97 err:
98         if (i > 0) {
99                 for (i = i - 1; i >= 0; i--) {
100                         led_classdev_unregister(&leds_data[i].cdev);
101                         pwm_free(leds_data[i].pwm);
102                 }
103         }
104
105         kfree(leds_data);
106
107         return ret;
108 }
109
110 static int __devexit led_pwm_remove(struct platform_device *pdev)
111 {
112         int i;
113         struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
114         struct led_pwm_data *leds_data;
115
116         leds_data = platform_get_drvdata(pdev);
117
118         for (i = 0; i < pdata->num_leds; i++) {
119                 led_classdev_unregister(&leds_data[i].cdev);
120                 pwm_free(leds_data[i].pwm);
121         }
122
123         kfree(leds_data);
124
125         return 0;
126 }
127
128 static struct platform_driver led_pwm_driver = {
129         .probe          = led_pwm_probe,
130         .remove         = __devexit_p(led_pwm_remove),
131         .driver         = {
132                 .name   = "leds_pwm",
133                 .owner  = THIS_MODULE,
134         },
135 };
136
137 static int __init led_pwm_init(void)
138 {
139         return platform_driver_register(&led_pwm_driver);
140 }
141
142 static void __exit led_pwm_exit(void)
143 {
144         platform_driver_unregister(&led_pwm_driver);
145 }
146
147 module_init(led_pwm_init);
148 module_exit(led_pwm_exit);
149
150 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
151 MODULE_DESCRIPTION("PWM LED driver for PXA");
152 MODULE_LICENSE("GPL");
153 MODULE_ALIAS("platform:leds-pwm");