Luotao Fu | 41c42ff | 2009-02-11 13:24:40 -0800 | [diff] [blame] | 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> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 24 | #include <linux/slab.h> |
Luotao Fu | 41c42ff | 2009-02-11 13:24:40 -0800 | [diff] [blame] | 25 | |
| 26 | struct led_pwm_data { |
| 27 | struct led_classdev cdev; |
| 28 | struct pwm_device *pwm; |
| 29 | unsigned int active_low; |
| 30 | unsigned int period; |
Luotao Fu | 41c42ff | 2009-02-11 13:24:40 -0800 | [diff] [blame] | 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); |
Lars-Peter Clausen | e459062 | 2009-11-27 06:17:38 +0100 | [diff] [blame] | 38 | unsigned int max = led_dat->cdev.max_brightness; |
Luotao Fu | 41c42ff | 2009-02-11 13:24:40 -0800 | [diff] [blame] | 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)) { |
Axel Lin | d8cc667 | 2011-01-25 15:07:14 -0800 | [diff] [blame^] | 72 | ret = PTR_ERR(led_dat->pwm); |
Luotao Fu | 41c42ff | 2009-02-11 13:24:40 -0800 | [diff] [blame] | 73 | dev_err(&pdev->dev, "unable to request PWM %d\n", |
| 74 | cur_led->pwm_id); |
| 75 | goto err; |
| 76 | } |
| 77 | |
| 78 | led_dat->cdev.name = cur_led->name; |
| 79 | led_dat->cdev.default_trigger = cur_led->default_trigger; |
| 80 | led_dat->active_low = cur_led->active_low; |
Luotao Fu | 41c42ff | 2009-02-11 13:24:40 -0800 | [diff] [blame] | 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; |
Lars-Peter Clausen | e459062 | 2009-11-27 06:17:38 +0100 | [diff] [blame] | 84 | led_dat->cdev.max_brightness = cur_led->max_brightness; |
Luotao Fu | 41c42ff | 2009-02-11 13:24:40 -0800 | [diff] [blame] | 85 | led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; |
| 86 | |
| 87 | ret = led_classdev_register(&pdev->dev, &led_dat->cdev); |
| 88 | if (ret < 0) { |
| 89 | pwm_free(led_dat->pwm); |
| 90 | goto err; |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | platform_set_drvdata(pdev, leds_data); |
| 95 | |
| 96 | return 0; |
| 97 | |
| 98 | err: |
| 99 | if (i > 0) { |
| 100 | for (i = i - 1; i >= 0; i--) { |
| 101 | led_classdev_unregister(&leds_data[i].cdev); |
| 102 | pwm_free(leds_data[i].pwm); |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | kfree(leds_data); |
| 107 | |
| 108 | return ret; |
| 109 | } |
| 110 | |
| 111 | static int __devexit led_pwm_remove(struct platform_device *pdev) |
| 112 | { |
| 113 | int i; |
| 114 | struct led_pwm_platform_data *pdata = pdev->dev.platform_data; |
| 115 | struct led_pwm_data *leds_data; |
| 116 | |
| 117 | leds_data = platform_get_drvdata(pdev); |
| 118 | |
| 119 | for (i = 0; i < pdata->num_leds; i++) { |
| 120 | led_classdev_unregister(&leds_data[i].cdev); |
| 121 | pwm_free(leds_data[i].pwm); |
| 122 | } |
| 123 | |
| 124 | kfree(leds_data); |
| 125 | |
| 126 | return 0; |
| 127 | } |
| 128 | |
| 129 | static struct platform_driver led_pwm_driver = { |
| 130 | .probe = led_pwm_probe, |
| 131 | .remove = __devexit_p(led_pwm_remove), |
| 132 | .driver = { |
| 133 | .name = "leds_pwm", |
| 134 | .owner = THIS_MODULE, |
| 135 | }, |
| 136 | }; |
| 137 | |
| 138 | static int __init led_pwm_init(void) |
| 139 | { |
| 140 | return platform_driver_register(&led_pwm_driver); |
| 141 | } |
| 142 | |
| 143 | static void __exit led_pwm_exit(void) |
| 144 | { |
| 145 | platform_driver_unregister(&led_pwm_driver); |
| 146 | } |
| 147 | |
| 148 | module_init(led_pwm_init); |
| 149 | module_exit(led_pwm_exit); |
| 150 | |
| 151 | MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); |
| 152 | MODULE_DESCRIPTION("PWM LED driver for PXA"); |
| 153 | MODULE_LICENSE("GPL"); |
| 154 | MODULE_ALIAS("platform:leds-pwm"); |