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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#include <linux/workqueue.h>
24
25struct gpio_led_data {
26 struct led_classdev cdev;
27 struct gpio_desc *gpiod;
28 struct work_struct work;
29 u8 new_level;
30 u8 can_sleep;
31 u8 blinking;
32 int (*platform_gpio_blink_set)(struct gpio_desc *desc, int state,
33 unsigned long *delay_on, unsigned long *delay_off);
34};
35
36static void gpio_led_work(struct work_struct *work)
37{
38 struct gpio_led_data *led_dat =
39 container_of(work, struct gpio_led_data, work);
40
41 if (led_dat->blinking) {
42 led_dat->platform_gpio_blink_set(led_dat->gpiod,
43 led_dat->new_level, NULL, NULL);
44 led_dat->blinking = 0;
45 } else
46 gpiod_set_value_cansleep(led_dat->gpiod, led_dat->new_level);
47}
48
49static void gpio_led_set(struct led_classdev *led_cdev,
50 enum led_brightness value)
51{
52 struct gpio_led_data *led_dat =
53 container_of(led_cdev, struct gpio_led_data, cdev);
54 int level;
55
56 if (value == LED_OFF)
57 level = 0;
58 else
59 level = 1;
60
61
62
63
64
65 if (led_dat->can_sleep) {
66 led_dat->new_level = level;
67 schedule_work(&led_dat->work);
68 } else {
69 if (led_dat->blinking) {
70 led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
71 NULL, NULL);
72 led_dat->blinking = 0;
73 } else
74 gpiod_set_value(led_dat->gpiod, level);
75 }
76}
77
78static int gpio_blink_set(struct led_classdev *led_cdev,
79 unsigned long *delay_on, unsigned long *delay_off)
80{
81 struct gpio_led_data *led_dat =
82 container_of(led_cdev, struct gpio_led_data, cdev);
83
84 led_dat->blinking = 1;
85 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
86 delay_on, delay_off);
87}
88
89static int create_gpio_led(const struct gpio_led *template,
90 struct gpio_led_data *led_dat, struct device *parent,
91 int (*blink_set)(struct gpio_desc *, int, unsigned long *,
92 unsigned long *))
93{
94 int ret, state;
95
96 led_dat->gpiod = template->gpiod;
97 if (!led_dat->gpiod) {
98
99
100
101
102
103 unsigned long flags = 0;
104
105
106 if (!gpio_is_valid(template->gpio)) {
107 dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n",
108 template->gpio, template->name);
109 return 0;
110 }
111
112 if (template->active_low)
113 flags |= GPIOF_ACTIVE_LOW;
114
115 ret = devm_gpio_request_one(parent, template->gpio, flags,
116 template->name);
117 if (ret < 0)
118 return ret;
119
120 led_dat->gpiod = gpio_to_desc(template->gpio);
121 if (IS_ERR(led_dat->gpiod))
122 return PTR_ERR(led_dat->gpiod);
123 }
124
125 led_dat->cdev.name = template->name;
126 led_dat->cdev.default_trigger = template->default_trigger;
127 led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
128 led_dat->blinking = 0;
129 if (blink_set) {
130 led_dat->platform_gpio_blink_set = blink_set;
131 led_dat->cdev.blink_set = gpio_blink_set;
132 }
133 led_dat->cdev.brightness_set = gpio_led_set;
134 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
135 state = !!gpiod_get_value_cansleep(led_dat->gpiod);
136 else
137 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
138 led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
139 if (!template->retain_state_suspended)
140 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
141
142 ret = gpiod_direction_output(led_dat->gpiod, state);
143 if (ret < 0)
144 return ret;
145
146 INIT_WORK(&led_dat->work, gpio_led_work);
147
148 return led_classdev_register(parent, &led_dat->cdev);
149}
150
151static void delete_gpio_led(struct gpio_led_data *led)
152{
153 led_classdev_unregister(&led->cdev);
154 cancel_work_sync(&led->work);
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
168static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
169{
170 struct device *dev = &pdev->dev;
171 struct fwnode_handle *child;
172 struct gpio_leds_priv *priv;
173 int count, ret;
174 struct device_node *np;
175
176 count = device_get_child_node_count(dev);
177 if (!count)
178 return ERR_PTR(-ENODEV);
179
180 priv = devm_kzalloc(dev, sizeof_gpio_leds_priv(count), GFP_KERNEL);
181 if (!priv)
182 return ERR_PTR(-ENOMEM);
183
184 device_for_each_child_node(dev, child) {
185 struct gpio_led led = {};
186 const char *state = NULL;
187
188 led.gpiod = devm_get_gpiod_from_child(dev, NULL, child);
189 if (IS_ERR(led.gpiod)) {
190 fwnode_handle_put(child);
191 ret = PTR_ERR(led.gpiod);
192 goto err;
193 }
194
195 np = to_of_node(child);
196
197 if (fwnode_property_present(child, "label")) {
198 fwnode_property_read_string(child, "label", &led.name);
199 } else {
200 if (IS_ENABLED(CONFIG_OF) && !led.name && np)
201 led.name = np->name;
202 if (!led.name) {
203 ret = -EINVAL;
204 goto err;
205 }
206 }
207 fwnode_property_read_string(child, "linux,default-trigger",
208 &led.default_trigger);
209
210 if (!fwnode_property_read_string(child, "default-state",
211 &state)) {
212 if (!strcmp(state, "keep"))
213 led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
214 else if (!strcmp(state, "on"))
215 led.default_state = LEDS_GPIO_DEFSTATE_ON;
216 else
217 led.default_state = LEDS_GPIO_DEFSTATE_OFF;
218 }
219
220 if (fwnode_property_present(child, "retain-state-suspended"))
221 led.retain_state_suspended = 1;
222
223 ret = create_gpio_led(&led, &priv->leds[priv->num_leds],
224 dev, NULL);
225 if (ret < 0) {
226 fwnode_handle_put(child);
227 goto err;
228 }
229 priv->num_leds++;
230 }
231
232 return priv;
233
234err:
235 for (count = priv->num_leds - 1; count >= 0; count--)
236 delete_gpio_led(&priv->leds[count]);
237 return ERR_PTR(ret);
238}
239
240static const struct of_device_id of_gpio_leds_match[] = {
241 { .compatible = "gpio-leds", },
242 {},
243};
244
245MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
246
247static int gpio_led_probe(struct platform_device *pdev)
248{
249 struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
250 struct gpio_leds_priv *priv;
251 int i, ret = 0;
252
253 if (pdata && pdata->num_leds) {
254 priv = devm_kzalloc(&pdev->dev,
255 sizeof_gpio_leds_priv(pdata->num_leds),
256 GFP_KERNEL);
257 if (!priv)
258 return -ENOMEM;
259
260 priv->num_leds = pdata->num_leds;
261 for (i = 0; i < priv->num_leds; i++) {
262 ret = create_gpio_led(&pdata->leds[i],
263 &priv->leds[i],
264 &pdev->dev, pdata->gpio_blink_set);
265 if (ret < 0) {
266
267 for (i = i - 1; i >= 0; i--)
268 delete_gpio_led(&priv->leds[i]);
269 return ret;
270 }
271 }
272 } else {
273 priv = gpio_leds_create(pdev);
274 if (IS_ERR(priv))
275 return PTR_ERR(priv);
276 }
277
278 platform_set_drvdata(pdev, priv);
279
280 return 0;
281}
282
283static int gpio_led_remove(struct platform_device *pdev)
284{
285 struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
286 int i;
287
288 for (i = 0; i < priv->num_leds; i++)
289 delete_gpio_led(&priv->leds[i]);
290
291 return 0;
292}
293
294static void gpio_led_shutdown(struct platform_device *pdev)
295{
296 struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
297 int i;
298
299 for (i = 0; i < priv->num_leds; i++) {
300 struct gpio_led_data *led = &priv->leds[i];
301
302 gpio_led_set(&led->cdev, LED_OFF);
303 }
304}
305
306static struct platform_driver gpio_led_driver = {
307 .probe = gpio_led_probe,
308 .remove = gpio_led_remove,
309 .shutdown = gpio_led_shutdown,
310 .driver = {
311 .name = "leds-gpio",
312 .of_match_table = of_gpio_leds_match,
313 },
314};
315
316module_platform_driver(gpio_led_driver);
317
318MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
319MODULE_DESCRIPTION("GPIO LED driver");
320MODULE_LICENSE("GPL");
321MODULE_ALIAS("platform:leds-gpio");
322
