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
24#include "leds.h"
25
26struct gpio_led_data {
27 struct led_classdev cdev;
28 struct gpio_desc *gpiod;
29 u8 can_sleep;
30 u8 blinking;
31 gpio_blink_set_t platform_gpio_blink_set;
32};
33
34static inline struct gpio_led_data *
35 cdev_to_gpio_led_data(struct led_classdev *led_cdev)
36{
37 return container_of(led_cdev, struct gpio_led_data, cdev);
38}
39
40static void gpio_led_set(struct led_classdev *led_cdev,
41 enum led_brightness value)
42{
43 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
44 int level;
45
46 if (value == LED_OFF)
47 level = 0;
48 else
49 level = 1;
50
51 if (led_dat->blinking) {
52 led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
53 NULL, NULL);
54 led_dat->blinking = 0;
55 } else {
56 if (led_dat->can_sleep)
57 gpiod_set_value_cansleep(desc: led_dat->gpiod, value: level);
58 else
59 gpiod_set_value(desc: led_dat->gpiod, value: level);
60 }
61}
62
63static int gpio_led_set_blocking(struct led_classdev *led_cdev,
64 enum led_brightness value)
65{
66 gpio_led_set(led_cdev, value);
67 return 0;
68}
69
70static int gpio_blink_set(struct led_classdev *led_cdev,
71 unsigned long *delay_on, unsigned long *delay_off)
72{
73 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
74
75 led_dat->blinking = 1;
76 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
77 delay_on, delay_off);
78}
79
80static int create_gpio_led(const struct gpio_led *template,
81 struct gpio_led_data *led_dat, struct device *parent,
82 struct fwnode_handle *fwnode, gpio_blink_set_t blink_set)
83{
84 struct led_init_data init_data = {};
85 struct pinctrl *pinctrl;
86 int ret, state;
87
88 led_dat->cdev.default_trigger = template->default_trigger;
89 led_dat->can_sleep = gpiod_cansleep(desc: led_dat->gpiod);
90 if (!led_dat->can_sleep)
91 led_dat->cdev.brightness_set = gpio_led_set;
92 else
93 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;
94 led_dat->blinking = 0;
95 if (blink_set) {
96 led_dat->platform_gpio_blink_set = blink_set;
97 led_dat->cdev.blink_set = gpio_blink_set;
98 }
99 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) {
100 state = gpiod_get_value_cansleep(desc: led_dat->gpiod);
101 if (state < 0)
102 return state;
103 } else {
104 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
105 }
106 led_dat->cdev.brightness = state;
107 led_dat->cdev.max_brightness = 1;
108 if (!template->retain_state_suspended)
109 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
110 if (template->panic_indicator)
111 led_dat->cdev.flags |= LED_PANIC_INDICATOR;
112 if (template->retain_state_shutdown)
113 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;
114
115 ret = gpiod_direction_output(desc: led_dat->gpiod, value: state);
116 if (ret < 0)
117 return ret;
118
119 if (template->name) {
120 led_dat->cdev.name = template->name;
121 ret = devm_led_classdev_register(parent, led_cdev: &led_dat->cdev);
122 } else {
123 init_data.fwnode = fwnode;
124 ret = devm_led_classdev_register_ext(parent, led_cdev: &led_dat->cdev,
125 init_data: &init_data);
126 }
127
128 if (ret)
129 return ret;
130
131 pinctrl = devm_pinctrl_get_select_default(dev: led_dat->cdev.dev);
132 ret = PTR_ERR_OR_ZERO(ptr: pinctrl);
133 /* pinctrl-%d not present, not an error */
134 if (ret == -ENODEV)
135 ret = 0;
136 if (ret) {
137 dev_warn(led_dat->cdev.dev, "Failed to select %pfw pinctrl: %d\n",
138 fwnode, ret);
139 }
140
141 return ret;
142}
143
144struct gpio_leds_priv {
145 int num_leds;
146 struct gpio_led_data leds[] __counted_by(num_leds);
147};
148
149static struct gpio_leds_priv *gpio_leds_create(struct device *dev)
150{
151 struct fwnode_handle *child;
152 struct gpio_leds_priv *priv;
153 int count, ret;
154
155 count = device_get_child_node_count(dev);
156 if (!count)
157 return ERR_PTR(error: -ENODEV);
158
159 priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
160 if (!priv)
161 return ERR_PTR(error: -ENOMEM);
162
163 device_for_each_child_node(dev, child) {
164 struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];
165 struct gpio_led led = {};
166
167 /*
168 * Acquire gpiod from DT with uninitialized label, which
169 * will be updated after LED class device is registered,
170 * Only then the final LED name is known.
171 */
172 led.gpiod = devm_fwnode_gpiod_get(dev, fwnode: child, NULL, flags: GPIOD_ASIS,
173 NULL);
174 if (IS_ERR(ptr: led.gpiod)) {
175 fwnode_handle_put(fwnode: 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 fwnode_handle_put(fwnode: child);
193 return ERR_PTR(error: ret);
194 }
195 /* Set gpiod label to match the corresponding LED name. */
196 gpiod_set_consumer_name(desc: led_dat->gpiod,
197 name: led_dat->cdev.dev->kobj.name);
198 priv->num_leds++;
199 }
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 unsigned long flags = GPIOF_OUT_INIT_LOW;
216 int ret;
217
218 /*
219 * This means the LED does not come from the device tree
220 * or ACPI, so let's try just getting it by index from the
221 * device, this will hit the board file, if any and get
222 * the GPIO from there.
223 */
224 gpiod = devm_gpiod_get_index_optional(dev, NULL, index: idx, flags: GPIOD_OUT_LOW);
225 if (IS_ERR(ptr: gpiod))
226 return gpiod;
227 if (gpiod) {
228 gpiod_set_consumer_name(desc: gpiod, name: template->name);
229 return gpiod;
230 }
231
232 /*
233 * This is the legacy code path for platform code that
234 * still uses GPIO numbers. Ultimately we would like to get
235 * rid of this block completely.
236 */
237
238 /* skip leds that aren't available */
239 if (!gpio_is_valid(number: template->gpio))
240 return ERR_PTR(error: -ENOENT);
241
242 if (template->active_low)
243 flags |= GPIOF_ACTIVE_LOW;
244
245 ret = devm_gpio_request_one(dev, gpio: template->gpio, flags,
246 label: template->name);
247 if (ret < 0)
248 return ERR_PTR(error: ret);
249
250 gpiod = gpio_to_desc(gpio: template->gpio);
251 if (!gpiod)
252 return ERR_PTR(error: -EINVAL);
253
254 return gpiod;
255}
256
257static int gpio_led_probe(struct platform_device *pdev)
258{
259 struct device *dev = &pdev->dev;
260 struct gpio_led_platform_data *pdata = dev_get_platdata(dev);
261 struct gpio_leds_priv *priv;
262 int i, ret;
263
264 if (pdata && pdata->num_leds) {
265 priv = devm_kzalloc(dev, struct_size(priv, leds, pdata->num_leds), 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(dev, idx: i, template);
279 if (IS_ERR(ptr: led_dat->gpiod)) {
280 dev_info(dev, "Skipping unavailable LED gpio %d (%s)\n",
281 template->gpio, template->name);
282 continue;
283 }
284
285 ret = create_gpio_led(template, led_dat, parent: dev, NULL,
286 blink_set: pdata->gpio_blink_set);
287 if (ret < 0)
288 return ret;
289 }
290 } else {
291 priv = gpio_leds_create(dev);
292 if (IS_ERR(ptr: priv))
293 return PTR_ERR(ptr: priv);
294 }
295
296 platform_set_drvdata(pdev, data: priv);
297
298 return 0;
299}
300
301static void gpio_led_shutdown(struct platform_device *pdev)
302{
303 struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
304 int i;
305
306 for (i = 0; i < priv->num_leds; i++) {
307 struct gpio_led_data *led = &priv->leds[i];
308
309 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
310 gpio_led_set(led_cdev: &led->cdev, value: LED_OFF);
311 }
312}
313
314static struct platform_driver gpio_led_driver = {
315 .probe = gpio_led_probe,
316 .shutdown = gpio_led_shutdown,
317 .driver = {
318 .name = "leds-gpio",
319 .of_match_table = of_gpio_leds_match,
320 },
321};
322
323module_platform_driver(gpio_led_driver);
324
325MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
326MODULE_DESCRIPTION("GPIO LED driver");
327MODULE_LICENSE("GPL");
328MODULE_ALIAS("platform:leds-gpio");
329

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