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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 struct device_node *np, 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 if (template->retain_state_shutdown)
138 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;
139
140 ret = gpiod_direction_output(led_dat->gpiod, state);
141 if (ret < 0)
142 return ret;
143
144 return devm_of_led_classdev_register(parent, np, &led_dat->cdev);
145}
146
147struct gpio_leds_priv {
148 int num_leds;
149 struct gpio_led_data leds[];
150};
151
152static inline int sizeof_gpio_leds_priv(int num_leds)
153{
154 return sizeof(struct gpio_leds_priv) +
155 (sizeof(struct gpio_led_data) * num_leds);
156}
157
158static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
159{
160 struct device *dev = &pdev->dev;
161 struct fwnode_handle *child;
162 struct gpio_leds_priv *priv;
163 int count, ret;
164
165 count = device_get_child_node_count(dev);
166 if (!count)
167 return ERR_PTR(-ENODEV);
168
169 priv = devm_kzalloc(dev, sizeof_gpio_leds_priv(count), GFP_KERNEL);
170 if (!priv)
171 return ERR_PTR(-ENOMEM);
172
173 device_for_each_child_node(dev, child) {
174 struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];
175 struct gpio_led led = {};
176 const char *state = NULL;
177 struct device_node *np = to_of_node(child);
178
179 ret = fwnode_property_read_string(child, "label", &led.name);
180 if (ret && IS_ENABLED(CONFIG_OF) && np)
181 led.name = np->name;
182 if (!led.name) {
183 fwnode_handle_put(child);
184 return ERR_PTR(-EINVAL);
185 }
186
187 led.gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL, child,
188 GPIOD_ASIS,
189 led.name);
190 if (IS_ERR(led.gpiod)) {
191 fwnode_handle_put(child);
192 return ERR_CAST(led.gpiod);
193 }
194
195 fwnode_property_read_string(child, "linux,default-trigger",
196 &led.default_trigger);
197
198 if (!fwnode_property_read_string(child, "default-state",
199 &state)) {
200 if (!strcmp(state, "keep"))
201 led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
202 else if (!strcmp(state, "on"))
203 led.default_state = LEDS_GPIO_DEFSTATE_ON;
204 else
205 led.default_state = LEDS_GPIO_DEFSTATE_OFF;
206 }
207
208 if (fwnode_property_present(child, "retain-state-suspended"))
209 led.retain_state_suspended = 1;
210 if (fwnode_property_present(child, "retain-state-shutdown"))
211 led.retain_state_shutdown = 1;
212 if (fwnode_property_present(child, "panic-indicator"))
213 led.panic_indicator = 1;
214
215 ret = create_gpio_led(&led, led_dat, dev, np, NULL);
216 if (ret < 0) {
217 fwnode_handle_put(child);
218 return ERR_PTR(ret);
219 }
220 led_dat->cdev.dev->of_node = np;
221 priv->num_leds++;
222 }
223
224 return priv;
225}
226
227static const struct of_device_id of_gpio_leds_match[] = {
228 { .compatible = "gpio-leds", },
229 {},
230};
231
232MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
233
234static int gpio_led_probe(struct platform_device *pdev)
235{
236 struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
237 struct gpio_leds_priv *priv;
238 int i, ret = 0;
239
240 if (pdata && pdata->num_leds) {
241 priv = devm_kzalloc(&pdev->dev,
242 sizeof_gpio_leds_priv(pdata->num_leds),
243 GFP_KERNEL);
244 if (!priv)
245 return -ENOMEM;
246
247 priv->num_leds = pdata->num_leds;
248 for (i = 0; i < priv->num_leds; i++) {
249 ret = create_gpio_led(&pdata->leds[i], &priv->leds[i],
250 &pdev->dev, NULL,
251 pdata->gpio_blink_set);
252 if (ret < 0)
253 return ret;
254 }
255 } else {
256 priv = gpio_leds_create(pdev);
257 if (IS_ERR(priv))
258 return PTR_ERR(priv);
259 }
260
261 platform_set_drvdata(pdev, priv);
262
263 return 0;
264}
265
266static void gpio_led_shutdown(struct platform_device *pdev)
267{
268 struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
269 int i;
270
271 for (i = 0; i < priv->num_leds; i++) {
272 struct gpio_led_data *led = &priv->leds[i];
273
274 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
275 gpio_led_set(&led->cdev, LED_OFF);
276 }
277}
278
279static struct platform_driver gpio_led_driver = {
280 .probe = gpio_led_probe,
281 .shutdown = gpio_led_shutdown,
282 .driver = {
283 .name = "leds-gpio",
284 .of_match_table = of_gpio_leds_match,
285 },
286};
287
288module_platform_driver(gpio_led_driver);
289
290MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
291MODULE_DESCRIPTION("GPIO LED driver");
292MODULE_LICENSE("GPL");
293MODULE_ALIAS("platform:leds-gpio");
294
