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/container_of.h>
10#include <linux/device.h>
11#include <linux/err.h>
12#include <linux/gpio.h>
13#include <linux/gpio/consumer.h>
14#include <linux/leds.h>
15#include <linux/mod_devicetable.h>
16#include <linux/module.h>
17#include <linux/overflow.h>
18#include <linux/pinctrl/consumer.h>
19#include <linux/platform_device.h>
20#include <linux/property.h>
21#include <linux/slab.h>
22#include <linux/types.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(desc: led_dat->gpiod, value: level);
56 else
57 gpiod_set_value(desc: led_dat->gpiod, value: 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 fwnode_handle *fwnode, gpio_blink_set_t blink_set)
81{
82 struct led_init_data init_data = {};
83 struct pinctrl *pinctrl;
84 int ret, state;
85
86 led_dat->cdev.default_trigger = template->default_trigger;
87 led_dat->can_sleep = gpiod_cansleep(desc: led_dat->gpiod);
88 if (!led_dat->can_sleep)
89 led_dat->cdev.brightness_set = gpio_led_set;
90 else
91 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;
92 led_dat->blinking = 0;
93 if (blink_set) {
94 led_dat->platform_gpio_blink_set = blink_set;
95 led_dat->cdev.blink_set = gpio_blink_set;
96 }
97 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) {
98 state = gpiod_get_value_cansleep(desc: led_dat->gpiod);
99 if (state < 0)
100 return state;
101 } else {
102 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
103 }
104 led_dat->cdev.brightness = state;
105 led_dat->cdev.max_brightness = 1;
106 if (!template->retain_state_suspended)
107 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
108 if (template->panic_indicator)
109 led_dat->cdev.flags |= LED_PANIC_INDICATOR;
110 if (template->retain_state_shutdown)
111 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;
112
113 ret = gpiod_direction_output(desc: led_dat->gpiod, value: state);
114 if (ret < 0)
115 return ret;
116
117 if (template->name) {
118 led_dat->cdev.name = template->name;
119 ret = devm_led_classdev_register(parent, led_cdev: &led_dat->cdev);
120 } else {
121 init_data.fwnode = fwnode;
122 ret = devm_led_classdev_register_ext(parent, led_cdev: &led_dat->cdev,
123 init_data: &init_data);
124 }
125
126 if (ret)
127 return ret;
128
129 pinctrl = devm_pinctrl_get_select_default(dev: led_dat->cdev.dev);
130 ret = PTR_ERR_OR_ZERO(ptr: pinctrl);
131 /* pinctrl-%d not present, not an error */
132 if (ret == -ENODEV)
133 ret = 0;
134 if (ret) {
135 dev_warn(led_dat->cdev.dev, "Failed to select %pfw pinctrl: %d\n",
136 fwnode, ret);
137 }
138
139 return ret;
140}
141
142struct gpio_leds_priv {
143 int num_leds;
144 struct gpio_led_data leds[] __counted_by(num_leds);
145};
146
147static struct gpio_leds_priv *gpio_leds_create(struct device *dev)
148{
149 struct gpio_leds_priv *priv;
150 int count, used, ret;
151
152 count = device_get_child_node_count(dev);
153 if (!count)
154 return ERR_PTR(error: -ENODEV);
155
156 priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
157 if (!priv)
158 return ERR_PTR(error: -ENOMEM);
159 priv->num_leds = count;
160 used = 0;
161
162 device_for_each_child_node_scoped(dev, child) {
163 struct gpio_led_data *led_dat = &priv->leds[used];
164 struct gpio_led led = {};
165
166 /*
167 * Acquire gpiod from DT with uninitialized label, which
168 * will be updated after LED class device is registered,
169 * Only then the final LED name is known.
170 */
171 led.gpiod = devm_fwnode_gpiod_get(dev, fwnode: child, NULL, flags: GPIOD_ASIS,
172 NULL);
173 if (IS_ERR(ptr: led.gpiod)) {
174 dev_err_probe(dev, err: PTR_ERR(ptr: led.gpiod), fmt: "Failed to get GPIO '%pfw'\n",
175 child);
176 return ERR_CAST(ptr: led.gpiod);
177 }
178
179 led_dat->gpiod = led.gpiod;
180
181 led.default_state = led_init_default_state_get(fwnode: child);
182
183 if (fwnode_property_present(fwnode: child, propname: "retain-state-suspended"))
184 led.retain_state_suspended = 1;
185 if (fwnode_property_present(fwnode: child, propname: "retain-state-shutdown"))
186 led.retain_state_shutdown = 1;
187 if (fwnode_property_present(fwnode: child, propname: "panic-indicator"))
188 led.panic_indicator = 1;
189
190 ret = create_gpio_led(template: &led, led_dat, parent: dev, fwnode: child, NULL);
191 if (ret < 0)
192 return ERR_PTR(error: ret);
193
194 /* Set gpiod label to match the corresponding LED name. */
195 gpiod_set_consumer_name(desc: led_dat->gpiod,
196 name: led_dat->cdev.dev->kobj.name);
197 used++;
198 }
199 priv->num_leds = used;
200
201 return priv;
202}
203
204static const struct of_device_id of_gpio_leds_match[] = {
205 { .compatible = "gpio-leds", },
206 {},
207};
208
209MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
210
211static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
212 const struct gpio_led *template)
213{
214 struct gpio_desc *gpiod;
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_optional(dev, NULL, index: idx, flags: GPIOD_OUT_LOW);
224 if (IS_ERR(ptr: gpiod))
225 return gpiod;
226 if (gpiod) {
227 gpiod_set_consumer_name(desc: gpiod, name: template->name);
228 return gpiod;
229 }
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(number: template->gpio))
239 return ERR_PTR(error: -ENOENT);
240
241 ret = devm_gpio_request_one(dev, gpio: template->gpio, GPIOF_OUT_INIT_LOW,
242 label: template->name);
243 if (ret < 0)
244 return ERR_PTR(error: ret);
245
246 gpiod = gpio_to_desc(gpio: template->gpio);
247 if (!gpiod)
248 return ERR_PTR(error: -EINVAL);
249
250 if (template->active_low ^ gpiod_is_active_low(desc: gpiod))
251 gpiod_toggle_active_low(desc: gpiod);
252
253 return gpiod;
254}
255
256static int gpio_led_probe(struct platform_device *pdev)
257{
258 struct device *dev = &pdev->dev;
259 struct gpio_led_platform_data *pdata = dev_get_platdata(dev);
260 struct gpio_leds_priv *priv;
261 int i, ret;
262
263 if (pdata && pdata->num_leds) {
264 priv = devm_kzalloc(dev, struct_size(priv, leds, pdata->num_leds), GFP_KERNEL);
265 if (!priv)
266 return -ENOMEM;
267
268 priv->num_leds = pdata->num_leds;
269 for (i = 0; i < priv->num_leds; i++) {
270 const struct gpio_led *template = &pdata->leds[i];
271 struct gpio_led_data *led_dat = &priv->leds[i];
272
273 if (template->gpiod)
274 led_dat->gpiod = template->gpiod;
275 else
276 led_dat->gpiod =
277 gpio_led_get_gpiod(dev, idx: i, template);
278 if (IS_ERR(ptr: led_dat->gpiod)) {
279 dev_info(dev, "Skipping unavailable LED gpio %d (%s)\n",
280 template->gpio, template->name);
281 continue;
282 }
283
284 ret = create_gpio_led(template, led_dat, parent: dev, NULL,
285 blink_set: pdata->gpio_blink_set);
286 if (ret < 0)
287 return ret;
288 }
289 } else {
290 priv = gpio_leds_create(dev);
291 if (IS_ERR(ptr: priv))
292 return PTR_ERR(ptr: priv);
293 }
294
295 platform_set_drvdata(pdev, data: priv);
296
297 return 0;
298}
299
300static void gpio_led_shutdown(struct platform_device *pdev)
301{
302 struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
303 int i;
304
305 for (i = 0; i < priv->num_leds; i++) {
306 struct gpio_led_data *led = &priv->leds[i];
307
308 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
309 gpio_led_set(led_cdev: &led->cdev, value: LED_OFF);
310 }
311}
312
313static struct platform_driver gpio_led_driver = {
314 .probe = gpio_led_probe,
315 .shutdown = gpio_led_shutdown,
316 .driver = {
317 .name = "leds-gpio",
318 .of_match_table = of_gpio_leds_match,
319 },
320};
321
322module_platform_driver(gpio_led_driver);
323
324MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
325MODULE_DESCRIPTION("GPIO LED driver");
326MODULE_LICENSE("GPL");
327MODULE_ALIAS("platform:leds-gpio");
328

source code of linux/drivers/leds/leds-gpio.c