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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/platform_device.h>
20#include <linux/property.h>
21#include <linux/slab.h>
22#include <linux/workqueue.h>
23
24struct gpio_led_data {
25 struct led_classdev cdev;
26 struct gpio_desc *gpiod;
27 struct work_struct work;
28 u8 new_level;
29 u8 can_sleep;
30 u8 blinking;
31 int (*platform_gpio_blink_set)(struct gpio_desc *desc, int state,
32 unsigned long *delay_on, unsigned long *delay_off);
33};
34
35static void gpio_led_work(struct work_struct *work)
36{
37 struct gpio_led_data *led_dat =
38 container_of(work, struct gpio_led_data, work);
39
40 if (led_dat->blinking) {
41 led_dat->platform_gpio_blink_set(led_dat->gpiod,
42 led_dat->new_level, NULL, NULL);
43 led_dat->blinking = 0;
44 } else
45 gpiod_set_value_cansleep(led_dat->gpiod, led_dat->new_level);
46}
47
48static void gpio_led_set(struct led_classdev *led_cdev,
49 enum led_brightness value)
50{
51 struct gpio_led_data *led_dat =
52 container_of(led_cdev, struct gpio_led_data, cdev);
53 int level;
54
55 if (value == LED_OFF)
56 level = 0;
57 else
58 level = 1;
59
60
61
62
63
64 if (led_dat->can_sleep) {
65 led_dat->new_level = level;
66 schedule_work(&led_dat->work);
67 } else {
68 if (led_dat->blinking) {
69 led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
70 NULL, NULL);
71 led_dat->blinking = 0;
72 } else
73 gpiod_set_value(led_dat->gpiod, level);
74 }
75}
76
77static int gpio_blink_set(struct led_classdev *led_cdev,
78 unsigned long *delay_on, unsigned long *delay_off)
79{
80 struct gpio_led_data *led_dat =
81 container_of(led_cdev, struct gpio_led_data, cdev);
82
83 led_dat->blinking = 1;
84 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
85 delay_on, delay_off);
86}
87
88static int create_gpio_led(const struct gpio_led *template,
89 struct gpio_led_data *led_dat, struct device *parent,
90 int (*blink_set)(struct gpio_desc *, int, unsigned long *,
91 unsigned long *))
92{
93 int ret, state;
94
95 led_dat->gpiod = template->gpiod;
96 if (!led_dat->gpiod) {
97
98
99
100
101
102 unsigned long flags = 0;
103
104
105 if (!gpio_is_valid(template->gpio)) {
106 dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n",
107 template->gpio, template->name);
108 return 0;
109 }
110
111 if (template->active_low)
112 flags |= GPIOF_ACTIVE_LOW;
113
114 ret = devm_gpio_request_one(parent, template->gpio, flags,
115 template->name);
116 if (ret < 0)
117 return ret;
118
119 led_dat->gpiod = gpio_to_desc(template->gpio);
120 if (IS_ERR(led_dat->gpiod))
121 return PTR_ERR(led_dat->gpiod);
122 }
123
124 led_dat->cdev.name = template->name;
125 led_dat->cdev.default_trigger = template->default_trigger;
126 led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
127 led_dat->blinking = 0;
128 if (blink_set) {
129 led_dat->platform_gpio_blink_set = blink_set;
130 led_dat->cdev.blink_set = gpio_blink_set;
131 }
132 led_dat->cdev.brightness_set = gpio_led_set;
133 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
134 state = !!gpiod_get_value_cansleep(led_dat->gpiod);
135 else
136 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
137 led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
138 if (!template->retain_state_suspended)
139 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
140
141 ret = gpiod_direction_output(led_dat->gpiod, state);
142 if (ret < 0)
143 return ret;
144
145 INIT_WORK(&led_dat->work, gpio_led_work);
146
147 return led_classdev_register(parent, &led_dat->cdev);
148}
149
150static void delete_gpio_led(struct gpio_led_data *led)
151{
152 led_classdev_unregister(&led->cdev);
153 cancel_work_sync(&led->work);
154}
155
156struct gpio_leds_priv {
157 int num_leds;
158 struct gpio_led_data leds[];
159};
160
161static inline int sizeof_gpio_leds_priv(int num_leds)
162{
163 return sizeof(struct gpio_leds_priv) +
164 (sizeof(struct gpio_led_data) * num_leds);
165}
166
167static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
168{
169 struct device *dev = &pdev->dev;
170 struct fwnode_handle *child;
171 struct gpio_leds_priv *priv;
172 int count, ret;
173 struct device_node *np;
174
175 count = device_get_child_node_count(dev);
176 if (!count)
177 return ERR_PTR(-ENODEV);
178
179 priv = devm_kzalloc(dev, sizeof_gpio_leds_priv(count), GFP_KERNEL);
180 if (!priv)
181 return ERR_PTR(-ENOMEM);
182
183 device_for_each_child_node(dev, child) {
184 struct gpio_led led = {};
185 const char *state = NULL;
186
187 led.gpiod = devm_get_gpiod_from_child(dev, child);
188 if (IS_ERR(led.gpiod)) {
189 fwnode_handle_put(child);
190 ret = PTR_ERR(led.gpiod);
191 goto err;
192 }
193
194 np = of_node(child);
195
196 if (fwnode_property_present(child, "label")) {
197 fwnode_property_read_string(child, "label", &led.name);
198 } else {
199 if (IS_ENABLED(CONFIG_OF) && !led.name && np)
200 led.name = np->name;
201 if (!led.name)
202 return ERR_PTR(-EINVAL);
203 }
204 fwnode_property_read_string(child, "linux,default-trigger",
205 &led.default_trigger);
206
207 if (!fwnode_property_read_string(child, "default-state",
208 &state)) {
209 if (!strcmp(state, "keep"))
210 led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
211 else if (!strcmp(state, "on"))
212 led.default_state = LEDS_GPIO_DEFSTATE_ON;
213 else
214 led.default_state = LEDS_GPIO_DEFSTATE_OFF;
215 }
216
217 if (fwnode_property_present(child, "retain-state-suspended"))
218 led.retain_state_suspended = 1;
219
220 ret = create_gpio_led(&led, &priv->leds[priv->num_leds++],
221 dev, NULL);
222 if (ret < 0) {
223 fwnode_handle_put(child);
224 goto err;
225 }
226 }
227
228 return priv;
229
230err:
231 for (count = priv->num_leds - 2; count >= 0; count--)
232 delete_gpio_led(&priv->leds[count]);
233 return ERR_PTR(ret);
234}
235
236static const struct of_device_id of_gpio_leds_match[] = {
237 { .compatible = "gpio-leds", },
238 {},
239};
240
241MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
242
243static int gpio_led_probe(struct platform_device *pdev)
244{
245 struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
246 struct gpio_leds_priv *priv;
247 int i, ret = 0;
248
249 if (pdata && pdata->num_leds) {
250 priv = devm_kzalloc(&pdev->dev,
251 sizeof_gpio_leds_priv(pdata->num_leds),
252 GFP_KERNEL);
253 if (!priv)
254 return -ENOMEM;
255
256 priv->num_leds = pdata->num_leds;
257 for (i = 0; i < priv->num_leds; i++) {
258 ret = create_gpio_led(&pdata->leds[i],
259 &priv->leds[i],
260 &pdev->dev, pdata->gpio_blink_set);
261 if (ret < 0) {
262
263 for (i = i - 1; i >= 0; i--)
264 delete_gpio_led(&priv->leds[i]);
265 return ret;
266 }
267 }
268 } else {
269 priv = gpio_leds_create(pdev);
270 if (IS_ERR(priv))
271 return PTR_ERR(priv);
272 }
273
274 platform_set_drvdata(pdev, priv);
275
276 return 0;
277}
278
279static int gpio_led_remove(struct platform_device *pdev)
280{
281 struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
282 int i;
283
284 for (i = 0; i < priv->num_leds; i++)
285 delete_gpio_led(&priv->leds[i]);
286
287 return 0;
288}
289
290static struct platform_driver gpio_led_driver = {
291 .probe = gpio_led_probe,
292 .remove = gpio_led_remove,
293 .driver = {
294 .name = "leds-gpio",
295 .of_match_table = 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
