Version:  2.0.40 2.2.26 2.4.37 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

Linux/drivers/leds/leds-gpio.c

  1 /*
  2  * LEDs driver for GPIOs
  3  *
  4  * Copyright (C) 2007 8D Technologies inc.
  5  * Raphael Assenat <raph@8d.com>
  6  * Copyright (C) 2008 Freescale Semiconductor, Inc.
  7  *
  8  * This program is free software; you can redistribute it and/or modify
  9  * it under the terms of the GNU General Public License version 2 as
 10  * published by the Free Software Foundation.
 11  *
 12  */
 13 #include <linux/err.h>
 14 #include <linux/gpio.h>
 15 #include <linux/gpio/consumer.h>
 16 #include <linux/kernel.h>
 17 #include <linux/leds.h>
 18 #include <linux/module.h>
 19 #include <linux/of.h>
 20 #include <linux/platform_device.h>
 21 #include <linux/property.h>
 22 #include <linux/slab.h>
 23 
 24 struct gpio_led_data {
 25         struct led_classdev cdev;
 26         struct gpio_desc *gpiod;
 27         u8 can_sleep;
 28         u8 blinking;
 29         int (*platform_gpio_blink_set)(struct gpio_desc *desc, int state,
 30                         unsigned long *delay_on, unsigned long *delay_off);
 31 };
 32 
 33 static void gpio_led_set(struct led_classdev *led_cdev,
 34         enum led_brightness value)
 35 {
 36         struct gpio_led_data *led_dat =
 37                 container_of(led_cdev, struct gpio_led_data, cdev);
 38         int level;
 39 
 40         if (value == LED_OFF)
 41                 level = 0;
 42         else
 43                 level = 1;
 44 
 45         if (led_dat->blinking) {
 46                 led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
 47                                                  NULL, NULL);
 48                 led_dat->blinking = 0;
 49         } else {
 50                 if (led_dat->can_sleep)
 51                         gpiod_set_value_cansleep(led_dat->gpiod, level);
 52                 else
 53                         gpiod_set_value(led_dat->gpiod, level);
 54         }
 55 }
 56 
 57 static int gpio_led_set_blocking(struct led_classdev *led_cdev,
 58         enum led_brightness value)
 59 {
 60         gpio_led_set(led_cdev, value);
 61         return 0;
 62 }
 63 
 64 static int gpio_blink_set(struct led_classdev *led_cdev,
 65         unsigned long *delay_on, unsigned long *delay_off)
 66 {
 67         struct gpio_led_data *led_dat =
 68                 container_of(led_cdev, struct gpio_led_data, cdev);
 69 
 70         led_dat->blinking = 1;
 71         return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
 72                                                 delay_on, delay_off);
 73 }
 74 
 75 static int create_gpio_led(const struct gpio_led *template,
 76         struct gpio_led_data *led_dat, struct device *parent,
 77         int (*blink_set)(struct gpio_desc *, int, unsigned long *,
 78                          unsigned long *))
 79 {
 80         int ret, state;
 81 
 82         led_dat->gpiod = template->gpiod;
 83         if (!led_dat->gpiod) {
 84                 /*
 85                  * This is the legacy code path for platform code that
 86                  * still uses GPIO numbers. Ultimately we would like to get
 87                  * rid of this block completely.
 88                  */
 89                 unsigned long flags = GPIOF_OUT_INIT_LOW;
 90 
 91                 /* skip leds that aren't available */
 92                 if (!gpio_is_valid(template->gpio)) {
 93                         dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n",
 94                                         template->gpio, template->name);
 95                         return 0;
 96                 }
 97 
 98                 if (template->active_low)
 99                         flags |= GPIOF_ACTIVE_LOW;
100 
101                 ret = devm_gpio_request_one(parent, template->gpio, flags,
102                                             template->name);
103                 if (ret < 0)
104                         return ret;
105 
106                 led_dat->gpiod = gpio_to_desc(template->gpio);
107                 if (!led_dat->gpiod)
108                         return -EINVAL;
109         }
110 
111         led_dat->cdev.name = template->name;
112         led_dat->cdev.default_trigger = template->default_trigger;
113         led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
114         if (!led_dat->can_sleep)
115                 led_dat->cdev.brightness_set = gpio_led_set;
116         else
117                 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;
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         if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
124                 state = !!gpiod_get_value_cansleep(led_dat->gpiod);
125         else
126                 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
127         led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
128         if (!template->retain_state_suspended)
129                 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
130         if (template->panic_indicator)
131                 led_dat->cdev.flags |= LED_PANIC_INDICATOR;
132 
133         ret = gpiod_direction_output(led_dat->gpiod, state);
134         if (ret < 0)
135                 return ret;
136 
137         return led_classdev_register(parent, &led_dat->cdev);
138 }
139 
140 struct gpio_leds_priv {
141         int num_leds;
142         struct gpio_led_data leds[];
143 };
144 
145 static inline int sizeof_gpio_leds_priv(int num_leds)
146 {
147         return sizeof(struct gpio_leds_priv) +
148                 (sizeof(struct gpio_led_data) * num_leds);
149 }
150 
151 static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
152 {
153         struct device *dev = &pdev->dev;
154         struct fwnode_handle *child;
155         struct gpio_leds_priv *priv;
156         int count, ret;
157         struct device_node *np;
158 
159         count = device_get_child_node_count(dev);
160         if (!count)
161                 return ERR_PTR(-ENODEV);
162 
163         priv = devm_kzalloc(dev, sizeof_gpio_leds_priv(count), GFP_KERNEL);
164         if (!priv)
165                 return ERR_PTR(-ENOMEM);
166 
167         device_for_each_child_node(dev, child) {
168                 struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];
169                 struct gpio_led led = {};
170                 const char *state = NULL;
171 
172                 led.gpiod = devm_get_gpiod_from_child(dev, NULL, child);
173                 if (IS_ERR(led.gpiod)) {
174                         fwnode_handle_put(child);
175                         ret = PTR_ERR(led.gpiod);
176                         goto err;
177                 }
178 
179                 np = to_of_node(child);
180 
181                 if (fwnode_property_present(child, "label")) {
182                         fwnode_property_read_string(child, "label", &led.name);
183                 } else {
184                         if (IS_ENABLED(CONFIG_OF) && !led.name && np)
185                                 led.name = np->name;
186                         if (!led.name) {
187                                 ret = -EINVAL;
188                                 goto err;
189                         }
190                 }
191                 fwnode_property_read_string(child, "linux,default-trigger",
192                                             &led.default_trigger);
193 
194                 if (!fwnode_property_read_string(child, "default-state",
195                                                  &state)) {
196                         if (!strcmp(state, "keep"))
197                                 led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
198                         else if (!strcmp(state, "on"))
199                                 led.default_state = LEDS_GPIO_DEFSTATE_ON;
200                         else
201                                 led.default_state = LEDS_GPIO_DEFSTATE_OFF;
202                 }
203 
204                 if (fwnode_property_present(child, "retain-state-suspended"))
205                         led.retain_state_suspended = 1;
206                 if (fwnode_property_present(child, "panic-indicator"))
207                         led.panic_indicator = 1;
208 
209                 ret = create_gpio_led(&led, led_dat, dev, NULL);
210                 if (ret < 0) {
211                         fwnode_handle_put(child);
212                         goto err;
213                 }
214                 led_dat->cdev.dev->of_node = np;
215                 priv->num_leds++;
216         }
217 
218         return priv;
219 
220 err:
221         for (count = priv->num_leds - 1; count >= 0; count--)
222                 led_classdev_unregister(&priv->leds[count].cdev);
223         return ERR_PTR(ret);
224 }
225 
226 static const struct of_device_id of_gpio_leds_match[] = {
227         { .compatible = "gpio-leds", },
228         {},
229 };
230 
231 MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
232 
233 static int gpio_led_probe(struct platform_device *pdev)
234 {
235         struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
236         struct gpio_leds_priv *priv;
237         int i, ret = 0;
238 
239         if (pdata && pdata->num_leds) {
240                 priv = devm_kzalloc(&pdev->dev,
241                                 sizeof_gpio_leds_priv(pdata->num_leds),
242                                         GFP_KERNEL);
243                 if (!priv)
244                         return -ENOMEM;
245 
246                 priv->num_leds = pdata->num_leds;
247                 for (i = 0; i < priv->num_leds; i++) {
248                         ret = create_gpio_led(&pdata->leds[i],
249                                               &priv->leds[i],
250                                               &pdev->dev, pdata->gpio_blink_set);
251                         if (ret < 0) {
252                                 /* On failure: unwind the led creations */
253                                 for (i = i - 1; i >= 0; i--)
254                                         led_classdev_unregister(
255                                                         &priv->leds[i].cdev);
256                                 return ret;
257                         }
258                 }
259         } else {
260                 priv = gpio_leds_create(pdev);
261                 if (IS_ERR(priv))
262                         return PTR_ERR(priv);
263         }
264 
265         platform_set_drvdata(pdev, priv);
266 
267         return 0;
268 }
269 
270 static int gpio_led_remove(struct platform_device *pdev)
271 {
272         struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
273         int i;
274 
275         for (i = 0; i < priv->num_leds; i++)
276                 led_classdev_unregister(&priv->leds[i].cdev);
277 
278         return 0;
279 }
280 
281 static void gpio_led_shutdown(struct platform_device *pdev)
282 {
283         struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
284         int i;
285 
286         for (i = 0; i < priv->num_leds; i++) {
287                 struct gpio_led_data *led = &priv->leds[i];
288 
289                 gpio_led_set(&led->cdev, LED_OFF);
290         }
291 }
292 
293 static struct platform_driver gpio_led_driver = {
294         .probe          = gpio_led_probe,
295         .remove         = gpio_led_remove,
296         .shutdown       = gpio_led_shutdown,
297         .driver         = {
298                 .name   = "leds-gpio",
299                 .of_match_table = of_gpio_leds_match,
300         },
301 };
302 
303 module_platform_driver(gpio_led_driver);
304 
305 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
306 MODULE_DESCRIPTION("GPIO LED driver");
307 MODULE_LICENSE("GPL");
308 MODULE_ALIAS("platform:leds-gpio");
309 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us