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Luotao Fu41c42ff2009-02-11 13:24:40 -08001/*
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>
Luotao Fu41c42ff2009-02-11 13:24:40 -080017#include <linux/platform_device.h>
Peter Ujfalusi08541cb2012-12-21 01:44:01 -080018#include <linux/of_platform.h>
Luotao Fu41c42ff2009-02-11 13:24:40 -080019#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 Heo5a0e3ad2010-03-24 17:04:11 +090024#include <linux/slab.h>
Florian Vaussardc971ff12013-01-28 06:00:59 -080025#include <linux/workqueue.h>
Luotao Fu41c42ff2009-02-11 13:24:40 -080026
27struct led_pwm_data {
28 struct led_classdev cdev;
29 struct pwm_device *pwm;
Florian Vaussardc971ff12013-01-28 06:00:59 -080030 struct work_struct work;
Sachin Kamatdcba9102012-11-25 12:24:55 +053031 unsigned int active_low;
Luotao Fu41c42ff2009-02-11 13:24:40 -080032 unsigned int period;
Florian Vaussardc971ff12013-01-28 06:00:59 -080033 int duty;
34 bool can_sleep;
Luotao Fu41c42ff2009-02-11 13:24:40 -080035};
36
Peter Ujfalusi0f868152012-12-21 01:43:56 -080037struct led_pwm_priv {
38 int num_leds;
39 struct led_pwm_data leds[0];
40};
41
Florian Vaussardc971ff12013-01-28 06:00:59 -080042static 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
54static 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
Luotao Fu41c42ff2009-02-11 13:24:40 -080062static 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);
Lars-Peter Clausene4590622009-11-27 06:17:38 +010067 unsigned int max = led_dat->cdev.max_brightness;
Xiubo Lifc1aee02013-12-11 01:19:42 -080068 unsigned long long duty = led_dat->period;
Luotao Fu41c42ff2009-02-11 13:24:40 -080069
Xiubo Lifc1aee02013-12-11 01:19:42 -080070 duty *= brightness;
71 do_div(duty, max);
Russell Kingd19a8a72014-04-06 15:20:18 -070072
73 if (led_dat->active_low)
74 duty = led_dat->period - duty;
75
Xiubo Lifc1aee02013-12-11 01:19:42 -080076 led_dat->duty = duty;
Florian Vaussardc971ff12013-01-28 06:00:59 -080077
78 if (led_dat->can_sleep)
79 schedule_work(&led_dat->work);
80 else
81 __led_pwm_set(led_dat);
Luotao Fu41c42ff2009-02-11 13:24:40 -080082}
83
Peter Ujfalusi0f868152012-12-21 01:43:56 -080084static inline size_t sizeof_pwm_leds_priv(int num_leds)
85{
86 return sizeof(struct led_pwm_priv) +
87 (sizeof(struct led_pwm_data) * num_leds);
88}
89
Russell King39236902014-04-06 15:20:03 -070090static void led_pwm_cleanup(struct led_pwm_priv *priv)
91{
92 while (priv->num_leds--) {
93 led_classdev_unregister(&priv->leds[priv->num_leds].cdev);
94 if (priv->leds[priv->num_leds].can_sleep)
95 cancel_work_sync(&priv->leds[priv->num_leds].work);
96 }
97}
98
Russell King5f7b03d2014-04-06 15:20:08 -070099static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
Russell Kingb795e6d2014-04-06 15:20:13 -0700100 struct led_pwm *led, struct device_node *child)
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800101{
Russell King5f7b03d2014-04-06 15:20:08 -0700102 struct led_pwm_data *led_data = &priv->leds[priv->num_leds];
Peter Ujfalusiaa1a6d62013-11-28 01:06:38 -0800103 int ret;
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800104
Russell King5f7b03d2014-04-06 15:20:08 -0700105 led_data->active_low = led->active_low;
Russell King5f7b03d2014-04-06 15:20:08 -0700106 led_data->cdev.name = led->name;
107 led_data->cdev.default_trigger = led->default_trigger;
108 led_data->cdev.brightness_set = led_pwm_set;
109 led_data->cdev.brightness = LED_OFF;
110 led_data->cdev.max_brightness = led->max_brightness;
111 led_data->cdev.flags = LED_CORE_SUSPENDRESUME;
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800112
Russell Kingb795e6d2014-04-06 15:20:13 -0700113 if (child)
114 led_data->pwm = devm_of_pwm_get(dev, child, NULL);
115 else
116 led_data->pwm = devm_pwm_get(dev, led->name);
Russell King5f7b03d2014-04-06 15:20:08 -0700117 if (IS_ERR(led_data->pwm)) {
118 ret = PTR_ERR(led_data->pwm);
119 dev_err(dev, "unable to request PWM for %s: %d\n",
120 led->name, ret);
121 return ret;
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800122 }
123
Russell King5f7b03d2014-04-06 15:20:08 -0700124 led_data->can_sleep = pwm_can_sleep(led_data->pwm);
125 if (led_data->can_sleep)
126 INIT_WORK(&led_data->work, led_pwm_work);
127
Linus Torvalds7c574cf2014-06-12 13:08:09 -0700128 led_data->period = pwm_get_period(led_data->pwm);
129 if (!led_data->period && (led->pwm_period_ns > 0))
130 led_data->period = led->pwm_period_ns;
131
Russell King5f7b03d2014-04-06 15:20:08 -0700132 ret = led_classdev_register(dev, &led_data->cdev);
133 if (ret == 0) {
134 priv->num_leds++;
135 } else {
136 dev_err(dev, "failed to register PWM led for %s: %d\n",
137 led->name, ret);
138 }
139
140 return ret;
141}
142
Russell Kingb795e6d2014-04-06 15:20:13 -0700143static int led_pwm_create_of(struct device *dev, struct led_pwm_priv *priv)
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800144{
145 struct device_node *child;
Russell Kingb795e6d2014-04-06 15:20:13 -0700146 struct led_pwm led;
147 int ret = 0;
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800148
Russell Kingb795e6d2014-04-06 15:20:13 -0700149 memset(&led, 0, sizeof(led));
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800150
Russell Kingb795e6d2014-04-06 15:20:13 -0700151 for_each_child_of_node(dev->of_node, child) {
152 led.name = of_get_property(child, "label", NULL) ? :
153 child->name;
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800154
Russell Kingb795e6d2014-04-06 15:20:13 -0700155 led.default_trigger = of_get_property(child,
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800156 "linux,default-trigger", NULL);
Russell Kingb0571e72014-04-06 15:20:24 -0700157 led.active_low = of_property_read_bool(child, "active-low");
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800158 of_property_read_u32(child, "max-brightness",
Russell Kingb795e6d2014-04-06 15:20:13 -0700159 &led.max_brightness);
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800160
Russell Kingb795e6d2014-04-06 15:20:13 -0700161 ret = led_pwm_add(dev, priv, &led, child);
162 if (ret) {
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800163 of_node_put(child);
Russell Kingb795e6d2014-04-06 15:20:13 -0700164 break;
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800165 }
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800166 }
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800167
Peter Ujfalusiaa1a6d62013-11-28 01:06:38 -0800168 return ret;
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800169}
170
Luotao Fu41c42ff2009-02-11 13:24:40 -0800171static int led_pwm_probe(struct platform_device *pdev)
172{
Jingoo Han87aae1e2013-07-30 01:07:35 -0700173 struct led_pwm_platform_data *pdata = dev_get_platdata(&pdev->dev);
Peter Ujfalusi0f868152012-12-21 01:43:56 -0800174 struct led_pwm_priv *priv;
Peter Ujfalusiaa1a6d62013-11-28 01:06:38 -0800175 int count, i;
176 int ret = 0;
Luotao Fu41c42ff2009-02-11 13:24:40 -0800177
Peter Ujfalusiaa1a6d62013-11-28 01:06:38 -0800178 if (pdata)
179 count = pdata->num_leds;
180 else
181 count = of_get_child_count(pdev->dev.of_node);
Luotao Fu41c42ff2009-02-11 13:24:40 -0800182
Peter Ujfalusiaa1a6d62013-11-28 01:06:38 -0800183 if (!count)
184 return -EINVAL;
185
186 priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count),
187 GFP_KERNEL);
188 if (!priv)
189 return -ENOMEM;
190
191 if (pdata) {
192 for (i = 0; i < count; i++) {
Russell Kingb795e6d2014-04-06 15:20:13 -0700193 ret = led_pwm_add(&pdev->dev, priv, &pdata->leds[i],
194 NULL);
Russell King5f7b03d2014-04-06 15:20:08 -0700195 if (ret)
196 break;
Luotao Fu41c42ff2009-02-11 13:24:40 -0800197 }
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800198 } else {
Russell Kingb795e6d2014-04-06 15:20:13 -0700199 ret = led_pwm_create_of(&pdev->dev, priv);
Russell King5f7b03d2014-04-06 15:20:08 -0700200 }
201
202 if (ret) {
203 led_pwm_cleanup(priv);
204 return ret;
Luotao Fu41c42ff2009-02-11 13:24:40 -0800205 }
206
Peter Ujfalusi0f868152012-12-21 01:43:56 -0800207 platform_set_drvdata(pdev, priv);
Luotao Fu41c42ff2009-02-11 13:24:40 -0800208
209 return 0;
Luotao Fu41c42ff2009-02-11 13:24:40 -0800210}
211
Bill Pemberton678e8a62012-11-19 13:26:00 -0500212static int led_pwm_remove(struct platform_device *pdev)
Luotao Fu41c42ff2009-02-11 13:24:40 -0800213{
Peter Ujfalusi0f868152012-12-21 01:43:56 -0800214 struct led_pwm_priv *priv = platform_get_drvdata(pdev);
Luotao Fu41c42ff2009-02-11 13:24:40 -0800215
Russell King39236902014-04-06 15:20:03 -0700216 led_pwm_cleanup(priv);
Luotao Fu41c42ff2009-02-11 13:24:40 -0800217
Luotao Fu41c42ff2009-02-11 13:24:40 -0800218 return 0;
219}
220
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800221static const struct of_device_id of_pwm_leds_match[] = {
222 { .compatible = "pwm-leds", },
223 {},
224};
225MODULE_DEVICE_TABLE(of, of_pwm_leds_match);
226
Luotao Fu41c42ff2009-02-11 13:24:40 -0800227static struct platform_driver led_pwm_driver = {
228 .probe = led_pwm_probe,
Bill Pembertondf07cf82012-11-19 13:20:20 -0500229 .remove = led_pwm_remove,
Luotao Fu41c42ff2009-02-11 13:24:40 -0800230 .driver = {
231 .name = "leds_pwm",
Sachin Kamat1e08f722013-09-28 04:38:31 -0700232 .of_match_table = of_pwm_leds_match,
Luotao Fu41c42ff2009-02-11 13:24:40 -0800233 },
234};
235
Axel Lin892a8842012-01-10 15:09:24 -0800236module_platform_driver(led_pwm_driver);
Luotao Fu41c42ff2009-02-11 13:24:40 -0800237
238MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
239MODULE_DESCRIPTION("PWM LED driver for PXA");
240MODULE_LICENSE("GPL");
241MODULE_ALIAS("platform:leds-pwm");