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9#include <linux/err.h>
10#include <linux/gpio.h>
11#include <linux/gpio/consumer.h>
12#include <linux/kernel.h>
13#include <linux/leds.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/platform_device.h>
17#include <linux/property.h>
18#include <linux/slab.h>
19
20struct gpio_led_data {
21 struct led_classdev cdev;
22 struct gpio_desc *gpiod;
23 u8 can_sleep;
24 u8 blinking;
25 gpio_blink_set_t platform_gpio_blink_set;
26};
27
28static inline struct gpio_led_data *
29 cdev_to_gpio_led_data(struct led_classdev *led_cdev)
30{
31 return container_of(led_cdev, struct gpio_led_data, cdev);
32}
33
34static void gpio_led_set(struct led_classdev *led_cdev,
35 enum led_brightness value)
36{
37 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_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
57static 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
64static 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 = cdev_to_gpio_led_data(led_cdev);
68
69 led_dat->blinking = 1;
70 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
71 delay_on, delay_off);
72}
73
74static int create_gpio_led(const struct gpio_led *template,
75 struct gpio_led_data *led_dat, struct device *parent,
76 struct device_node *np, gpio_blink_set_t blink_set)
77{
78 int ret, state;
79
80 led_dat->cdev.name = template->name;
81 led_dat->cdev.default_trigger = template->default_trigger;
82 led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
83 if (!led_dat->can_sleep)
84 led_dat->cdev.brightness_set = gpio_led_set;
85 else
86 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;
87 led_dat->blinking = 0;
88 if (blink_set) {
89 led_dat->platform_gpio_blink_set = blink_set;
90 led_dat->cdev.blink_set = gpio_blink_set;
91 }
92 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) {
93 state = gpiod_get_value_cansleep(led_dat->gpiod);
94 if (state < 0)
95 return state;
96 } else {
97 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
98 }
99 led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
100 if (!template->retain_state_suspended)
101 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
102 if (template->panic_indicator)
103 led_dat->cdev.flags |= LED_PANIC_INDICATOR;
104 if (template->retain_state_shutdown)
105 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;
106
107 ret = gpiod_direction_output(led_dat->gpiod, state);
108 if (ret < 0)
109 return ret;
110
111 return devm_of_led_classdev_register(parent, np, &led_dat->cdev);
112}
113
114struct gpio_leds_priv {
115 int num_leds;
116 struct gpio_led_data leds[];
117};
118
119static inline int sizeof_gpio_leds_priv(int num_leds)
120{
121 return sizeof(struct gpio_leds_priv) +
122 (sizeof(struct gpio_led_data) * num_leds);
123}
124
125static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
126{
127 struct device *dev = &pdev->dev;
128 struct fwnode_handle *child;
129 struct gpio_leds_priv *priv;
130 int count, ret;
131
132 count = device_get_child_node_count(dev);
133 if (!count)
134 return ERR_PTR(-ENODEV);
135
136 priv = devm_kzalloc(dev, sizeof_gpio_leds_priv(count), GFP_KERNEL);
137 if (!priv)
138 return ERR_PTR(-ENOMEM);
139
140 device_for_each_child_node(dev, child) {
141 struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];
142 struct gpio_led led = {};
143 const char *state = NULL;
144 struct device_node *np = to_of_node(child);
145
146 ret = fwnode_property_read_string(child, "label", &led.name);
147 if (ret && IS_ENABLED(CONFIG_OF) && np)
148 led.name = np->name;
149 if (!led.name) {
150 fwnode_handle_put(child);
151 return ERR_PTR(-EINVAL);
152 }
153
154 led.gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL, child,
155 GPIOD_ASIS,
156 led.name);
157 if (IS_ERR(led.gpiod)) {
158 fwnode_handle_put(child);
159 return ERR_CAST(led.gpiod);
160 }
161
162 led_dat->gpiod = led.gpiod;
163
164 fwnode_property_read_string(child, "linux,default-trigger",
165 &led.default_trigger);
166
167 if (!fwnode_property_read_string(child, "default-state",
168 &state)) {
169 if (!strcmp(state, "keep"))
170 led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
171 else if (!strcmp(state, "on"))
172 led.default_state = LEDS_GPIO_DEFSTATE_ON;
173 else
174 led.default_state = LEDS_GPIO_DEFSTATE_OFF;
175 }
176
177 if (fwnode_property_present(child, "retain-state-suspended"))
178 led.retain_state_suspended = 1;
179 if (fwnode_property_present(child, "retain-state-shutdown"))
180 led.retain_state_shutdown = 1;
181 if (fwnode_property_present(child, "panic-indicator"))
182 led.panic_indicator = 1;
183
184 ret = create_gpio_led(&led, led_dat, dev, np, NULL);
185 if (ret < 0) {
186 fwnode_handle_put(child);
187 return ERR_PTR(ret);
188 }
189 priv->num_leds++;
190 }
191
192 return priv;
193}
194
195static const struct of_device_id of_gpio_leds_match[] = {
196 { .compatible = "gpio-leds", },
197 {},
198};
199
200MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
201
202static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
203 const struct gpio_led *template)
204{
205 struct gpio_desc *gpiod;
206 unsigned long flags = GPIOF_OUT_INIT_LOW;
207 int ret;
208
209
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212
213
214
215 gpiod = devm_gpiod_get_index(dev, NULL, idx, flags);
216 if (!IS_ERR(gpiod)) {
217 gpiod_set_consumer_name(gpiod, template->name);
218 return gpiod;
219 }
220 if (PTR_ERR(gpiod) != -ENOENT)
221 return gpiod;
222
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226
227
228
229
230 if (!gpio_is_valid(template->gpio))
231 return ERR_PTR(-ENOENT);
232
233 if (template->active_low)
234 flags |= GPIOF_ACTIVE_LOW;
235
236 ret = devm_gpio_request_one(dev, template->gpio, flags,
237 template->name);
238 if (ret < 0)
239 return ERR_PTR(ret);
240
241 gpiod = gpio_to_desc(template->gpio);
242 if (!gpiod)
243 return ERR_PTR(-EINVAL);
244
245 return gpiod;
246}
247
248static int gpio_led_probe(struct platform_device *pdev)
249{
250 struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
251 struct gpio_leds_priv *priv;
252 int i, ret = 0;
253
254 if (pdata && pdata->num_leds) {
255 priv = devm_kzalloc(&pdev->dev,
256 sizeof_gpio_leds_priv(pdata->num_leds),
257 GFP_KERNEL);
258 if (!priv)
259 return -ENOMEM;
260
261 priv->num_leds = pdata->num_leds;
262 for (i = 0; i < priv->num_leds; i++) {
263 const struct gpio_led *template = &pdata->leds[i];
264 struct gpio_led_data *led_dat = &priv->leds[i];
265
266 if (template->gpiod)
267 led_dat->gpiod = template->gpiod;
268 else
269 led_dat->gpiod =
270 gpio_led_get_gpiod(&pdev->dev,
271 i, template);
272 if (IS_ERR(led_dat->gpiod)) {
273 dev_info(&pdev->dev, "Skipping unavailable LED gpio %d (%s)\n",
274 template->gpio, template->name);
275 continue;
276 }
277
278 ret = create_gpio_led(template, led_dat,
279 &pdev->dev, NULL,
280 pdata->gpio_blink_set);
281 if (ret < 0)
282 return ret;
283 }
284 } else {
285 priv = gpio_leds_create(pdev);
286 if (IS_ERR(priv))
287 return PTR_ERR(priv);
288 }
289
290 platform_set_drvdata(pdev, priv);
291
292 return 0;
293}
294
295static void gpio_led_shutdown(struct platform_device *pdev)
296{
297 struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
298 int i;
299
300 for (i = 0; i < priv->num_leds; i++) {
301 struct gpio_led_data *led = &priv->leds[i];
302
303 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
304 gpio_led_set(&led->cdev, LED_OFF);
305 }
306}
307
308static struct platform_driver gpio_led_driver = {
309 .probe = gpio_led_probe,
310 .shutdown = gpio_led_shutdown,
311 .driver = {
312 .name = "leds-gpio",
313 .of_match_table = of_gpio_leds_match,
314 },
315};
316
317module_platform_driver(gpio_led_driver);
318
319MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
320MODULE_DESCRIPTION("GPIO LED driver");
321MODULE_LICENSE("GPL");
322MODULE_ALIAS("platform:leds-gpio");
323
