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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
24struct gpio_led_data {
25 struct led_classdev cdev;
26 struct gpio_desc *gpiod;
27 u8 can_sleep;
28 u8 blinking;
29 gpio_blink_set_t platform_gpio_blink_set;
30};
31
32static inline struct gpio_led_data *
33 cdev_to_gpio_led_data(struct led_classdev *led_cdev)
34{
35 return container_of(led_cdev, struct gpio_led_data, cdev);
36}
37
38static void gpio_led_set(struct led_classdev *led_cdev,
39 enum led_brightness value)
40{
41 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
42 int level;
43
44 if (value == LED_OFF)
45 level = 0;
46 else
47 level = 1;
48
49 if (led_dat->blinking) {
50 led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
51 NULL, NULL);
52 led_dat->blinking = 0;
53 } else {
54 if (led_dat->can_sleep)
55 gpiod_set_value_cansleep(led_dat->gpiod, level);
56 else
57 gpiod_set_value(led_dat->gpiod, level);
58 }
59}
60
61static int gpio_led_set_blocking(struct led_classdev *led_cdev,
62 enum led_brightness value)
63{
64 gpio_led_set(led_cdev, value);
65 return 0;
66}
67
68static int gpio_blink_set(struct led_classdev *led_cdev,
69 unsigned long *delay_on, unsigned long *delay_off)
70{
71 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
72
73 led_dat->blinking = 1;
74 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
75 delay_on, delay_off);
76}
77
78static int create_gpio_led(const struct gpio_led *template,
79 struct gpio_led_data *led_dat, struct device *parent,
80 gpio_blink_set_t blink_set)
81{
82 int ret, state;
83
84 led_dat->gpiod = template->gpiod;
85 if (!led_dat->gpiod) {
86
87
88
89
90
91 unsigned long flags = GPIOF_OUT_INIT_LOW;
92
93
94 if (!gpio_is_valid(template->gpio)) {
95 dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n",
96 template->gpio, template->name);
97 return 0;
98 }
99
100 if (template->active_low)
101 flags |= GPIOF_ACTIVE_LOW;
102
103 ret = devm_gpio_request_one(parent, template->gpio, flags,
104 template->name);
105 if (ret < 0)
106 return ret;
107
108 led_dat->gpiod = gpio_to_desc(template->gpio);
109 if (!led_dat->gpiod)
110 return -EINVAL;
111 }
112
113 led_dat->cdev.name = template->name;
114 led_dat->cdev.default_trigger = template->default_trigger;
115 led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
116 if (!led_dat->can_sleep)
117 led_dat->cdev.brightness_set = gpio_led_set;
118 else
119 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;
120 led_dat->blinking = 0;
121 if (blink_set) {
122 led_dat->platform_gpio_blink_set = blink_set;
123 led_dat->cdev.blink_set = gpio_blink_set;
124 }
125 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) {
126 state = gpiod_get_value_cansleep(led_dat->gpiod);
127 if (state < 0)
128 return state;
129 } else {
130 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
131 }
132 led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
133 if (!template->retain_state_suspended)
134 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
135 if (template->panic_indicator)
136 led_dat->cdev.flags |= LED_PANIC_INDICATOR;
137
138 ret = gpiod_direction_output(led_dat->gpiod, state);
139 if (ret < 0)
140 return ret;
141
142 return devm_led_classdev_register(parent, &led_dat->cdev);
143}
144
145struct gpio_leds_priv {
146 int num_leds;
147 struct gpio_led_data leds[];
148};
149
150static inline int sizeof_gpio_leds_priv(int num_leds)
151{
152 return sizeof(struct gpio_leds_priv) +
153 (sizeof(struct gpio_led_data) * num_leds);
154}
155
156static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
157{
158 struct device *dev = &pdev->dev;
159 struct fwnode_handle *child;
160 struct gpio_leds_priv *priv;
161 int count, ret;
162
163 count = device_get_child_node_count(dev);
164 if (!count)
165 return ERR_PTR(-ENODEV);
166
167 priv = devm_kzalloc(dev, sizeof_gpio_leds_priv(count), GFP_KERNEL);
168 if (!priv)
169 return ERR_PTR(-ENOMEM);
170
171 device_for_each_child_node(dev, child) {
172 struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];
173 struct gpio_led led = {};
174 const char *state = NULL;
175 struct device_node *np = to_of_node(child);
176
177 led.gpiod = devm_get_gpiod_from_child(dev, NULL, child);
178 if (IS_ERR(led.gpiod)) {
179 fwnode_handle_put(child);
180 return ERR_CAST(led.gpiod);
181 }
182
183 ret = fwnode_property_read_string(child, "label", &led.name);
184 if (ret && IS_ENABLED(CONFIG_OF) && np)
185 led.name = np->name;
186 if (!led.name) {
187 fwnode_handle_put(child);
188 return ERR_PTR(-EINVAL);
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 return ERR_PTR(ret);
213 }
214 led_dat->cdev.dev->of_node = np;
215 priv->num_leds++;
216 }
217
218 return priv;
219}
220
221static const struct of_device_id of_gpio_leds_match[] = {
222 { .compatible = "gpio-leds", },
223 {},
224};
225
226MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
227
228static int gpio_led_probe(struct platform_device *pdev)
229{
230 struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
231 struct gpio_leds_priv *priv;
232 int i, ret = 0;
233
234 if (pdata && pdata->num_leds) {
235 priv = devm_kzalloc(&pdev->dev,
236 sizeof_gpio_leds_priv(pdata->num_leds),
237 GFP_KERNEL);
238 if (!priv)
239 return -ENOMEM;
240
241 priv->num_leds = pdata->num_leds;
242 for (i = 0; i < priv->num_leds; i++) {
243 ret = create_gpio_led(&pdata->leds[i],
244 &priv->leds[i],
245 &pdev->dev, pdata->gpio_blink_set);
246 if (ret < 0)
247 return ret;
248 }
249 } else {
250 priv = gpio_leds_create(pdev);
251 if (IS_ERR(priv))
252 return PTR_ERR(priv);
253 }
254
255 platform_set_drvdata(pdev, priv);
256
257 return 0;
258}
259
260static void gpio_led_shutdown(struct platform_device *pdev)
261{
262 struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
263 int i;
264
265 for (i = 0; i < priv->num_leds; i++) {
266 struct gpio_led_data *led = &priv->leds[i];
267
268 gpio_led_set(&led->cdev, LED_OFF);
269 }
270}
271
272static struct platform_driver gpio_led_driver = {
273 .probe = gpio_led_probe,
274 .shutdown = gpio_led_shutdown,
275 .driver = {
276 .name = "leds-gpio",
277 .of_match_table = of_gpio_leds_match,
278 },
279};
280
281module_platform_driver(gpio_led_driver);
282
283MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
284MODULE_DESCRIPTION("GPIO LED driver");
285MODULE_LICENSE("GPL");
286MODULE_ALIAS("platform:leds-gpio");
287
