dma40: make d40_log_buf_to_lli static
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / leds / leds-pwm.c
blobda3fa8dcdf5b924f71a7f117c05009f0fc671514
1 /*
2 * linux/drivers/leds-pwm.c
4 * simple PWM based LED control
6 * Copyright 2009 Luotao Fu @ Pengutronix (l.fu@pengutronix.de)
8 * based on leds-gpio.c by Raphael Assenat <raph@8d.com>
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.
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 #include <linux/slab.h>
26 struct led_pwm_data {
27 struct led_classdev cdev;
28 struct pwm_device *pwm;
29 unsigned int active_low;
30 unsigned int period;
33 static void led_pwm_set(struct led_classdev *led_cdev,
34 enum led_brightness brightness)
36 struct led_pwm_data *led_dat =
37 container_of(led_cdev, struct led_pwm_data, cdev);
38 unsigned int max = led_dat->cdev.max_brightness;
39 unsigned int period = led_dat->period;
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);
50 static int led_pwm_probe(struct platform_device *pdev)
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;
57 if (!pdata)
58 return -EBUSY;
60 leds_data = kzalloc(sizeof(struct led_pwm_data) * pdata->num_leds,
61 GFP_KERNEL);
62 if (!leds_data)
63 return -ENOMEM;
65 for (i = 0; i < pdata->num_leds; i++) {
66 cur_led = &pdata->leds[i];
67 led_dat = &leds_data[i];
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;
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->period = cur_led->pwm_period_ns;
81 led_dat->cdev.brightness_set = led_pwm_set;
82 led_dat->cdev.brightness = LED_OFF;
83 led_dat->cdev.max_brightness = cur_led->max_brightness;
84 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
86 ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
87 if (ret < 0) {
88 pwm_free(led_dat->pwm);
89 goto err;
93 platform_set_drvdata(pdev, leds_data);
95 return 0;
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);
105 kfree(leds_data);
107 return ret;
110 static int __devexit led_pwm_remove(struct platform_device *pdev)
112 int i;
113 struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
114 struct led_pwm_data *leds_data;
116 leds_data = platform_get_drvdata(pdev);
118 for (i = 0; i < pdata->num_leds; i++) {
119 led_classdev_unregister(&leds_data[i].cdev);
120 pwm_free(leds_data[i].pwm);
123 kfree(leds_data);
125 return 0;
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,
137 static int __init led_pwm_init(void)
139 return platform_driver_register(&led_pwm_driver);
142 static void __exit led_pwm_exit(void)
144 platform_driver_unregister(&led_pwm_driver);
147 module_init(led_pwm_init);
148 module_exit(led_pwm_exit);
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");