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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 Kingb795e6d2014-04-06 15:20:13 -0700124 if (child)
125 led_data->period = pwm_get_period(led_data->pwm);
126
Russell King5f7b03d2014-04-06 15:20:08 -0700127 led_data->can_sleep = pwm_can_sleep(led_data->pwm);
128 if (led_data->can_sleep)
129 INIT_WORK(&led_data->work, led_pwm_work);
130
Linus Torvalds7c574cf2014-06-12 13:08:09 -0700131 led_data->period = pwm_get_period(led_data->pwm);
132 if (!led_data->period && (led->pwm_period_ns > 0))
133 led_data->period = led->pwm_period_ns;
134
Russell King5f7b03d2014-04-06 15:20:08 -0700135 ret = led_classdev_register(dev, &led_data->cdev);
136 if (ret == 0) {
137 priv->num_leds++;
138 } else {
139 dev_err(dev, "failed to register PWM led for %s: %d\n",
140 led->name, ret);
141 }
142
143 return ret;
144}
145
Russell Kingb795e6d2014-04-06 15:20:13 -0700146static int led_pwm_create_of(struct device *dev, struct led_pwm_priv *priv)
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800147{
148 struct device_node *child;
Russell Kingb795e6d2014-04-06 15:20:13 -0700149 struct led_pwm led;
150 int ret = 0;
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800151
Russell Kingb795e6d2014-04-06 15:20:13 -0700152 memset(&led, 0, sizeof(led));
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800153
Russell Kingb795e6d2014-04-06 15:20:13 -0700154 for_each_child_of_node(dev->of_node, child) {
155 led.name = of_get_property(child, "label", NULL) ? :
156 child->name;
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800157
Russell Kingb795e6d2014-04-06 15:20:13 -0700158 led.default_trigger = of_get_property(child,
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800159 "linux,default-trigger", NULL);
Russell Kingb0571e72014-04-06 15:20:24 -0700160 led.active_low = of_property_read_bool(child, "active-low");
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800161 of_property_read_u32(child, "max-brightness",
Russell Kingb795e6d2014-04-06 15:20:13 -0700162 &led.max_brightness);
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800163
Russell Kingb795e6d2014-04-06 15:20:13 -0700164 ret = led_pwm_add(dev, priv, &led, child);
165 if (ret) {
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800166 of_node_put(child);
Russell Kingb795e6d2014-04-06 15:20:13 -0700167 break;
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800168 }
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800169 }
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800170
Peter Ujfalusiaa1a6d62013-11-28 01:06:38 -0800171 return ret;
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800172}
173
Luotao Fu41c42ff2009-02-11 13:24:40 -0800174static int led_pwm_probe(struct platform_device *pdev)
175{
Jingoo Han87aae1e2013-07-30 01:07:35 -0700176 struct led_pwm_platform_data *pdata = dev_get_platdata(&pdev->dev);
Peter Ujfalusi0f868152012-12-21 01:43:56 -0800177 struct led_pwm_priv *priv;
Peter Ujfalusiaa1a6d62013-11-28 01:06:38 -0800178 int count, i;
179 int ret = 0;
Luotao Fu41c42ff2009-02-11 13:24:40 -0800180
Peter Ujfalusiaa1a6d62013-11-28 01:06:38 -0800181 if (pdata)
182 count = pdata->num_leds;
183 else
184 count = of_get_child_count(pdev->dev.of_node);
Luotao Fu41c42ff2009-02-11 13:24:40 -0800185
Peter Ujfalusiaa1a6d62013-11-28 01:06:38 -0800186 if (!count)
187 return -EINVAL;
188
189 priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count),
190 GFP_KERNEL);
191 if (!priv)
192 return -ENOMEM;
193
194 if (pdata) {
195 for (i = 0; i < count; i++) {
Russell Kingb795e6d2014-04-06 15:20:13 -0700196 ret = led_pwm_add(&pdev->dev, priv, &pdata->leds[i],
197 NULL);
Russell King5f7b03d2014-04-06 15:20:08 -0700198 if (ret)
199 break;
Luotao Fu41c42ff2009-02-11 13:24:40 -0800200 }
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800201 } else {
Russell Kingb795e6d2014-04-06 15:20:13 -0700202 ret = led_pwm_create_of(&pdev->dev, priv);
Russell King5f7b03d2014-04-06 15:20:08 -0700203 }
204
205 if (ret) {
206 led_pwm_cleanup(priv);
207 return ret;
Luotao Fu41c42ff2009-02-11 13:24:40 -0800208 }
209
Peter Ujfalusi0f868152012-12-21 01:43:56 -0800210 platform_set_drvdata(pdev, priv);
Luotao Fu41c42ff2009-02-11 13:24:40 -0800211
212 return 0;
Luotao Fu41c42ff2009-02-11 13:24:40 -0800213}
214
Bill Pemberton678e8a62012-11-19 13:26:00 -0500215static int led_pwm_remove(struct platform_device *pdev)
Luotao Fu41c42ff2009-02-11 13:24:40 -0800216{
Peter Ujfalusi0f868152012-12-21 01:43:56 -0800217 struct led_pwm_priv *priv = platform_get_drvdata(pdev);
Luotao Fu41c42ff2009-02-11 13:24:40 -0800218
Russell King39236902014-04-06 15:20:03 -0700219 led_pwm_cleanup(priv);
Luotao Fu41c42ff2009-02-11 13:24:40 -0800220
Luotao Fu41c42ff2009-02-11 13:24:40 -0800221 return 0;
222}
223
Peter Ujfalusi08541cb2012-12-21 01:44:01 -0800224static const struct of_device_id of_pwm_leds_match[] = {
225 { .compatible = "pwm-leds", },
226 {},
227};
228MODULE_DEVICE_TABLE(of, of_pwm_leds_match);
229
Luotao Fu41c42ff2009-02-11 13:24:40 -0800230static struct platform_driver led_pwm_driver = {
231 .probe = led_pwm_probe,
Bill Pembertondf07cf82012-11-19 13:20:20 -0500232 .remove = led_pwm_remove,
Luotao Fu41c42ff2009-02-11 13:24:40 -0800233 .driver = {
234 .name = "leds_pwm",
Sachin Kamat1e08f722013-09-28 04:38:31 -0700235 .of_match_table = of_pwm_leds_match,
Luotao Fu41c42ff2009-02-11 13:24:40 -0800236 },
237};
238
Axel Lin892a8842012-01-10 15:09:24 -0800239module_platform_driver(led_pwm_driver);
Luotao Fu41c42ff2009-02-11 13:24:40 -0800240
241MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
242MODULE_DESCRIPTION("PWM LED driver for PXA");
243MODULE_LICENSE("GPL");
244MODULE_ALIAS("platform:leds-pwm");