1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * LEDs driver for GPIOs
4 *
5 * Copyright (C) 2007 8D Technologies inc.
6 * Raphael Assenat <raph@8d.com>
7 * Copyright (C) 2008 Freescale Semiconductor, Inc.
8 */
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
20 struct 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
28 static inline struct gpio_led_data *
cdev_to_gpio_led_data(struct led_classdev * led_cdev)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
gpio_led_set(struct led_classdev * led_cdev,enum led_brightness value)34 static 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
gpio_led_set_blocking(struct led_classdev * led_cdev,enum led_brightness value)57 static 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
gpio_blink_set(struct led_classdev * led_cdev,unsigned long * delay_on,unsigned long * delay_off)64 static 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
create_gpio_led(const struct gpio_led * template,struct gpio_led_data * led_dat,struct device * parent,struct fwnode_handle * fwnode,gpio_blink_set_t blink_set)74 static int create_gpio_led(const struct gpio_led *template,
75 struct gpio_led_data *led_dat, struct device *parent,
76 struct fwnode_handle *fwnode, gpio_blink_set_t blink_set)
77 {
78 struct led_init_data init_data = {};
79 int ret, state;
80
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 if (template->name) {
112 led_dat->cdev.name = template->name;
113 ret = devm_led_classdev_register(parent, &led_dat->cdev);
114 } else {
115 init_data.fwnode = fwnode;
116 ret = devm_led_classdev_register_ext(parent, &led_dat->cdev,
117 &init_data);
118 }
119
120 return ret;
121 }
122
123 struct gpio_leds_priv {
124 int num_leds;
125 struct gpio_led_data leds[];
126 };
127
sizeof_gpio_leds_priv(int num_leds)128 static inline int sizeof_gpio_leds_priv(int num_leds)
129 {
130 return sizeof(struct gpio_leds_priv) +
131 (sizeof(struct gpio_led_data) * num_leds);
132 }
133
gpio_leds_create(struct platform_device * pdev)134 static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
135 {
136 struct device *dev = &pdev->dev;
137 struct fwnode_handle *child;
138 struct gpio_leds_priv *priv;
139 int count, ret;
140
141 count = device_get_child_node_count(dev);
142 if (!count)
143 return ERR_PTR(-ENODEV);
144
145 priv = devm_kzalloc(dev, sizeof_gpio_leds_priv(count), GFP_KERNEL);
146 if (!priv)
147 return ERR_PTR(-ENOMEM);
148
149 device_for_each_child_node(dev, child) {
150 struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];
151 struct gpio_led led = {};
152 const char *state = NULL;
153
154 /*
155 * Acquire gpiod from DT with uninitialized label, which
156 * will be updated after LED class device is registered,
157 * Only then the final LED name is known.
158 */
159 led.gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL, child,
160 GPIOD_ASIS,
161 NULL);
162 if (IS_ERR(led.gpiod)) {
163 fwnode_handle_put(child);
164 return ERR_CAST(led.gpiod);
165 }
166
167 led_dat->gpiod = led.gpiod;
168
169 fwnode_property_read_string(child, "linux,default-trigger",
170 &led.default_trigger);
171
172 if (!fwnode_property_read_string(child, "default-state",
173 &state)) {
174 if (!strcmp(state, "keep"))
175 led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
176 else if (!strcmp(state, "on"))
177 led.default_state = LEDS_GPIO_DEFSTATE_ON;
178 else
179 led.default_state = LEDS_GPIO_DEFSTATE_OFF;
180 }
181
182 if (fwnode_property_present(child, "retain-state-suspended"))
183 led.retain_state_suspended = 1;
184 if (fwnode_property_present(child, "retain-state-shutdown"))
185 led.retain_state_shutdown = 1;
186 if (fwnode_property_present(child, "panic-indicator"))
187 led.panic_indicator = 1;
188
189 ret = create_gpio_led(&led, led_dat, dev, child, NULL);
190 if (ret < 0) {
191 fwnode_handle_put(child);
192 return ERR_PTR(ret);
193 }
194 /* Set gpiod label to match the corresponding LED name. */
195 gpiod_set_consumer_name(led_dat->gpiod,
196 led_dat->cdev.dev->kobj.name);
197 priv->num_leds++;
198 }
199
200 return priv;
201 }
202
203 static const struct of_device_id of_gpio_leds_match[] = {
204 { .compatible = "gpio-leds", },
205 {},
206 };
207
208 MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
209
gpio_led_get_gpiod(struct device * dev,int idx,const struct gpio_led * template)210 static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
211 const struct gpio_led *template)
212 {
213 struct gpio_desc *gpiod;
214 unsigned long flags = GPIOF_OUT_INIT_LOW;
215 int ret;
216
217 /*
218 * This means the LED does not come from the device tree
219 * or ACPI, so let's try just getting it by index from the
220 * device, this will hit the board file, if any and get
221 * the GPIO from there.
222 */
223 gpiod = devm_gpiod_get_index(dev, NULL, idx, flags);
224 if (!IS_ERR(gpiod)) {
225 gpiod_set_consumer_name(gpiod, template->name);
226 return gpiod;
227 }
228 if (PTR_ERR(gpiod) != -ENOENT)
229 return gpiod;
230
231 /*
232 * This is the legacy code path for platform code that
233 * still uses GPIO numbers. Ultimately we would like to get
234 * rid of this block completely.
235 */
236
237 /* skip leds that aren't available */
238 if (!gpio_is_valid(template->gpio))
239 return ERR_PTR(-ENOENT);
240
241 if (template->active_low)
242 flags |= GPIOF_ACTIVE_LOW;
243
244 ret = devm_gpio_request_one(dev, template->gpio, flags,
245 template->name);
246 if (ret < 0)
247 return ERR_PTR(ret);
248
249 gpiod = gpio_to_desc(template->gpio);
250 if (!gpiod)
251 return ERR_PTR(-EINVAL);
252
253 return gpiod;
254 }
255
gpio_led_probe(struct platform_device * pdev)256 static int gpio_led_probe(struct platform_device *pdev)
257 {
258 struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
259 struct gpio_leds_priv *priv;
260 int i, ret = 0;
261
262 if (pdata && pdata->num_leds) {
263 priv = devm_kzalloc(&pdev->dev,
264 sizeof_gpio_leds_priv(pdata->num_leds),
265 GFP_KERNEL);
266 if (!priv)
267 return -ENOMEM;
268
269 priv->num_leds = pdata->num_leds;
270 for (i = 0; i < priv->num_leds; i++) {
271 const struct gpio_led *template = &pdata->leds[i];
272 struct gpio_led_data *led_dat = &priv->leds[i];
273
274 if (template->gpiod)
275 led_dat->gpiod = template->gpiod;
276 else
277 led_dat->gpiod =
278 gpio_led_get_gpiod(&pdev->dev,
279 i, template);
280 if (IS_ERR(led_dat->gpiod)) {
281 dev_info(&pdev->dev, "Skipping unavailable LED gpio %d (%s)\n",
282 template->gpio, template->name);
283 continue;
284 }
285
286 ret = create_gpio_led(template, led_dat,
287 &pdev->dev, NULL,
288 pdata->gpio_blink_set);
289 if (ret < 0)
290 return ret;
291 }
292 } else {
293 priv = gpio_leds_create(pdev);
294 if (IS_ERR(priv))
295 return PTR_ERR(priv);
296 }
297
298 platform_set_drvdata(pdev, priv);
299
300 return 0;
301 }
302
gpio_led_shutdown(struct platform_device * pdev)303 static void gpio_led_shutdown(struct platform_device *pdev)
304 {
305 struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
306 int i;
307
308 for (i = 0; i < priv->num_leds; i++) {
309 struct gpio_led_data *led = &priv->leds[i];
310
311 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
312 gpio_led_set(&led->cdev, LED_OFF);
313 }
314 }
315
316 static struct platform_driver gpio_led_driver = {
317 .probe = gpio_led_probe,
318 .shutdown = gpio_led_shutdown,
319 .driver = {
320 .name = "leds-gpio",
321 .of_match_table = of_gpio_leds_match,
322 },
323 };
324
325 module_platform_driver(gpio_led_driver);
326
327 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
328 MODULE_DESCRIPTION("GPIO LED driver");
329 MODULE_LICENSE("GPL");
330 MODULE_ALIAS("platform:leds-gpio");
331