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13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/platform_device.h>
16#include <linux/gpio.h>
17#include <linux/leds.h>
18#include <linux/of_platform.h>
19#include <linux/of_gpio.h>
20#include <linux/slab.h>
21#include <linux/workqueue.h>
22#include <linux/module.h>
23#include <linux/pinctrl/consumer.h>
24
25struct gpio_led_data {
26 struct led_classdev cdev;
27 unsigned gpio;
28 struct work_struct work;
29 u8 new_level;
30 u8 can_sleep;
31 u8 active_low;
32 u8 blinking;
33 int (*platform_gpio_blink_set)(unsigned gpio, int state,
34 unsigned long *delay_on, unsigned long *delay_off);
35};
36
37static void gpio_led_work(struct work_struct *work)
38{
39 struct gpio_led_data *led_dat =
40 container_of(work, struct gpio_led_data, work);
41
42 if (led_dat->blinking) {
43 led_dat->platform_gpio_blink_set(led_dat->gpio,
44 led_dat->new_level,
45 NULL, NULL);
46 led_dat->blinking = 0;
47 } else
48 gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
49}
50
51static void gpio_led_set(struct led_classdev *led_cdev,
52 enum led_brightness value)
53{
54 struct gpio_led_data *led_dat =
55 container_of(led_cdev, struct gpio_led_data, cdev);
56 int level;
57
58 if (value == LED_OFF)
59 level = 0;
60 else
61 level = 1;
62
63 if (led_dat->active_low)
64 level = !level;
65
66
67
68
69
70 if (led_dat->can_sleep) {
71 led_dat->new_level = level;
72 schedule_work(&led_dat->work);
73 } else {
74 if (led_dat->blinking) {
75 led_dat->platform_gpio_blink_set(led_dat->gpio, level,
76 NULL, NULL);
77 led_dat->blinking = 0;
78 } else
79 gpio_set_value(led_dat->gpio, level);
80 }
81}
82
83static int gpio_blink_set(struct led_classdev *led_cdev,
84 unsigned long *delay_on, unsigned long *delay_off)
85{
86 struct gpio_led_data *led_dat =
87 container_of(led_cdev, struct gpio_led_data, cdev);
88
89 led_dat->blinking = 1;
90 return led_dat->platform_gpio_blink_set(led_dat->gpio, GPIO_LED_BLINK,
91 delay_on, delay_off);
92}
93
94static int __devinit create_gpio_led(const struct gpio_led *template,
95 struct gpio_led_data *led_dat, struct device *parent,
96 int (*blink_set)(unsigned, int, unsigned long *, unsigned long *))
97{
98 int ret, state;
99
100 led_dat->gpio = -1;
101
102
103 if (!gpio_is_valid(template->gpio)) {
104 printk(KERN_INFO "Skipping unavailable LED gpio %d (%s)\n",
105 template->gpio, template->name);
106 return 0;
107 }
108
109 ret = gpio_request(template->gpio, template->name);
110 if (ret < 0)
111 return ret;
112
113 led_dat->cdev.name = template->name;
114 led_dat->cdev.default_trigger = template->default_trigger;
115 led_dat->gpio = template->gpio;
116 led_dat->can_sleep = gpio_cansleep(template->gpio);
117 led_dat->active_low = template->active_low;
118 led_dat->blinking = 0;
119 if (blink_set) {
120 led_dat->platform_gpio_blink_set = blink_set;
121 led_dat->cdev.blink_set = gpio_blink_set;
122 }
123 led_dat->cdev.brightness_set = gpio_led_set;
124 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
125 state = !!gpio_get_value_cansleep(led_dat->gpio) ^ led_dat->active_low;
126 else
127 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
128 led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
129 if (!template->retain_state_suspended)
130 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
131
132 ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state);
133 if (ret < 0)
134 goto err;
135
136 INIT_WORK(&led_dat->work, gpio_led_work);
137
138 ret = led_classdev_register(parent, &led_dat->cdev);
139 if (ret < 0)
140 goto err;
141
142 return 0;
143err:
144 gpio_free(led_dat->gpio);
145 return ret;
146}
147
148static void delete_gpio_led(struct gpio_led_data *led)
149{
150 if (!gpio_is_valid(led->gpio))
151 return;
152 led_classdev_unregister(&led->cdev);
153 cancel_work_sync(&led->work);
154 gpio_free(led->gpio);
155}
156
157struct gpio_leds_priv {
158 int num_leds;
159 struct gpio_led_data leds[];
160};
161
162static inline int sizeof_gpio_leds_priv(int num_leds)
163{
164 return sizeof(struct gpio_leds_priv) +
165 (sizeof(struct gpio_led_data) * num_leds);
166}
167
168
169#ifdef CONFIG_OF_GPIO
170static struct gpio_leds_priv * __devinit gpio_leds_create_of(struct platform_device *pdev)
171{
172 struct device_node *np = pdev->dev.of_node, *child;
173 struct gpio_leds_priv *priv;
174 int count, ret;
175
176
177 count = of_get_child_count(np);
178 if (!count)
179 return NULL;
180
181 priv = devm_kzalloc(&pdev->dev, sizeof_gpio_leds_priv(count),
182 GFP_KERNEL);
183 if (!priv)
184 return NULL;
185
186 for_each_child_of_node(np, child) {
187 struct gpio_led led = {};
188 enum of_gpio_flags flags;
189 const char *state;
190
191 led.gpio = of_get_gpio_flags(child, 0, &flags);
192 led.active_low = flags & OF_GPIO_ACTIVE_LOW;
193 led.name = of_get_property(child, "label", NULL) ? : child->name;
194 led.default_trigger =
195 of_get_property(child, "linux,default-trigger", NULL);
196 state = of_get_property(child, "default-state", NULL);
197 if (state) {
198 if (!strcmp(state, "keep"))
199 led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
200 else if (!strcmp(state, "on"))
201 led.default_state = LEDS_GPIO_DEFSTATE_ON;
202 else
203 led.default_state = LEDS_GPIO_DEFSTATE_OFF;
204 }
205
206 ret = create_gpio_led(&led, &priv->leds[priv->num_leds++],
207 &pdev->dev, NULL);
208 if (ret < 0) {
209 of_node_put(child);
210 goto err;
211 }
212 }
213
214 return priv;
215
216err:
217 for (count = priv->num_leds - 2; count >= 0; count--)
218 delete_gpio_led(&priv->leds[count]);
219 return NULL;
220}
221
222static const struct of_device_id of_gpio_leds_match[] = {
223 { .compatible = "gpio-leds", },
224 {},
225};
226#else
227static struct gpio_leds_priv * __devinit gpio_leds_create_of(struct platform_device *pdev)
228{
229 return NULL;
230}
231#endif
232
233
234static int __devinit gpio_led_probe(struct platform_device *pdev)
235{
236 struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
237 struct gpio_leds_priv *priv;
238 struct pinctrl *pinctrl;
239 int i, ret = 0;
240
241 pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
242 if (IS_ERR(pinctrl))
243 dev_warn(&pdev->dev,
244 "pins are not configured from the driver\n");
245
246 if (pdata && pdata->num_leds) {
247 priv = devm_kzalloc(&pdev->dev,
248 sizeof_gpio_leds_priv(pdata->num_leds),
249 GFP_KERNEL);
250 if (!priv)
251 return -ENOMEM;
252
253 priv->num_leds = pdata->num_leds;
254 for (i = 0; i < priv->num_leds; i++) {
255 ret = create_gpio_led(&pdata->leds[i],
256 &priv->leds[i],
257 &pdev->dev, pdata->gpio_blink_set);
258 if (ret < 0) {
259
260 for (i = i - 1; i >= 0; i--)
261 delete_gpio_led(&priv->leds[i]);
262 return ret;
263 }
264 }
265 } else {
266 priv = gpio_leds_create_of(pdev);
267 if (!priv)
268 return -ENODEV;
269 }
270
271 platform_set_drvdata(pdev, priv);
272
273 return 0;
274}
275
276static int __devexit gpio_led_remove(struct platform_device *pdev)
277{
278 struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
279 int i;
280
281 for (i = 0; i < priv->num_leds; i++)
282 delete_gpio_led(&priv->leds[i]);
283
284 platform_set_drvdata(pdev, NULL);
285
286 return 0;
287}
288
289static struct platform_driver gpio_led_driver = {
290 .probe = gpio_led_probe,
291 .remove = __devexit_p(gpio_led_remove),
292 .driver = {
293 .name = "leds-gpio",
294 .owner = THIS_MODULE,
295 .of_match_table = of_match_ptr(of_gpio_leds_match),
296 },
297};
298
299module_platform_driver(gpio_led_driver);
300
301MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
302MODULE_DESCRIPTION("GPIO LED driver");
303MODULE_LICENSE("GPL");
304MODULE_ALIAS("platform:leds-gpio");
305
