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/pinctrl/consumer.h>
17 #include <linux/platform_device.h>
18 #include <linux/property.h>
19 #include <linux/slab.h>
20 #include "leds.h"
21
22 struct gpio_led_data {
23 struct led_classdev cdev;
24 struct gpio_desc *gpiod;
25 u8 can_sleep;
26 u8 blinking;
27 gpio_blink_set_t platform_gpio_blink_set;
28 };
29
30 static inline struct gpio_led_data *
cdev_to_gpio_led_data(struct led_classdev * led_cdev)31 cdev_to_gpio_led_data(struct led_classdev *led_cdev)
32 {
33 return container_of(led_cdev, struct gpio_led_data, cdev);
34 }
35
gpio_led_set(struct led_classdev * led_cdev,enum led_brightness value)36 static void gpio_led_set(struct led_classdev *led_cdev,
37 enum led_brightness value)
38 {
39 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
40 int level;
41
42 if (value == LED_OFF)
43 level = 0;
44 else
45 level = 1;
46
47 if (led_dat->blinking) {
48 led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
49 NULL, NULL);
50 led_dat->blinking = 0;
51 } else {
52 if (led_dat->can_sleep)
53 gpiod_set_value_cansleep(led_dat->gpiod, level);
54 else
55 gpiod_set_value(led_dat->gpiod, level);
56 }
57 }
58
gpio_led_set_blocking(struct led_classdev * led_cdev,enum led_brightness value)59 static int gpio_led_set_blocking(struct led_classdev *led_cdev,
60 enum led_brightness value)
61 {
62 gpio_led_set(led_cdev, value);
63 return 0;
64 }
65
gpio_blink_set(struct led_classdev * led_cdev,unsigned long * delay_on,unsigned long * delay_off)66 static int gpio_blink_set(struct led_classdev *led_cdev,
67 unsigned long *delay_on, unsigned long *delay_off)
68 {
69 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
70
71 led_dat->blinking = 1;
72 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
73 delay_on, delay_off);
74 }
75
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)76 static int create_gpio_led(const struct gpio_led *template,
77 struct gpio_led_data *led_dat, struct device *parent,
78 struct fwnode_handle *fwnode, gpio_blink_set_t blink_set)
79 {
80 struct led_init_data init_data = {};
81 struct pinctrl *pinctrl;
82 int ret, state;
83
84 led_dat->cdev.default_trigger = template->default_trigger;
85 led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
86 if (!led_dat->can_sleep)
87 led_dat->cdev.brightness_set = gpio_led_set;
88 else
89 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;
90 led_dat->blinking = 0;
91 if (blink_set) {
92 led_dat->platform_gpio_blink_set = blink_set;
93 led_dat->cdev.blink_set = gpio_blink_set;
94 }
95 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) {
96 state = gpiod_get_value_cansleep(led_dat->gpiod);
97 if (state < 0)
98 return state;
99 } else {
100 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
101 }
102 led_dat->cdev.brightness = state;
103 led_dat->cdev.max_brightness = 1;
104 if (!template->retain_state_suspended)
105 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
106 if (template->panic_indicator)
107 led_dat->cdev.flags |= LED_PANIC_INDICATOR;
108 if (template->retain_state_shutdown)
109 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;
110
111 ret = gpiod_direction_output(led_dat->gpiod, state);
112 if (ret < 0)
113 return ret;
114
115 if (template->name) {
116 led_dat->cdev.name = template->name;
117 ret = devm_led_classdev_register(parent, &led_dat->cdev);
118 } else {
119 init_data.fwnode = fwnode;
120 ret = devm_led_classdev_register_ext(parent, &led_dat->cdev,
121 &init_data);
122 }
123
124 if (ret)
125 return ret;
126
127 pinctrl = devm_pinctrl_get_select_default(led_dat->cdev.dev);
128 if (IS_ERR(pinctrl)) {
129 ret = PTR_ERR(pinctrl);
130 if (ret != -ENODEV) {
131 dev_warn(led_dat->cdev.dev,
132 "Failed to select %pOF pinctrl: %d\n",
133 to_of_node(fwnode), ret);
134 } else {
135 /* pinctrl-%d not present, not an error */
136 ret = 0;
137 }
138 }
139
140 return ret;
141 }
142
143 struct gpio_leds_priv {
144 int num_leds;
145 struct gpio_led_data leds[];
146 };
147
gpio_leds_create(struct platform_device * pdev)148 static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
149 {
150 struct device *dev = &pdev->dev;
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(-ENODEV);
158
159 priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
160 if (!priv)
161 return ERR_PTR(-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, child, NULL, GPIOD_ASIS,
173 NULL);
174 if (IS_ERR(led.gpiod)) {
175 fwnode_handle_put(child);
176 return ERR_CAST(led.gpiod);
177 }
178
179 led_dat->gpiod = led.gpiod;
180
181 led.default_state = led_init_default_state_get(child);
182
183 if (fwnode_property_present(child, "retain-state-suspended"))
184 led.retain_state_suspended = 1;
185 if (fwnode_property_present(child, "retain-state-shutdown"))
186 led.retain_state_shutdown = 1;
187 if (fwnode_property_present(child, "panic-indicator"))
188 led.panic_indicator = 1;
189
190 ret = create_gpio_led(&led, led_dat, dev, child, NULL);
191 if (ret < 0) {
192 fwnode_handle_put(child);
193 return ERR_PTR(ret);
194 }
195 /* Set gpiod label to match the corresponding LED name. */
196 gpiod_set_consumer_name(led_dat->gpiod,
197 led_dat->cdev.dev->kobj.name);
198 priv->num_leds++;
199 }
200
201 return priv;
202 }
203
204 static const struct of_device_id of_gpio_leds_match[] = {
205 { .compatible = "gpio-leds", },
206 {},
207 };
208
209 MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
210
gpio_led_get_gpiod(struct device * dev,int idx,const struct gpio_led * template)211 static 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(dev, NULL, idx, GPIOD_OUT_LOW);
225 if (!IS_ERR(gpiod)) {
226 gpiod_set_consumer_name(gpiod, template->name);
227 return gpiod;
228 }
229 if (PTR_ERR(gpiod) != -ENOENT)
230 return gpiod;
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(template->gpio))
240 return ERR_PTR(-ENOENT);
241
242 if (template->active_low)
243 flags |= GPIOF_ACTIVE_LOW;
244
245 ret = devm_gpio_request_one(dev, template->gpio, flags,
246 template->name);
247 if (ret < 0)
248 return ERR_PTR(ret);
249
250 gpiod = gpio_to_desc(template->gpio);
251 if (!gpiod)
252 return ERR_PTR(-EINVAL);
253
254 return gpiod;
255 }
256
gpio_led_probe(struct platform_device * pdev)257 static int gpio_led_probe(struct platform_device *pdev)
258 {
259 struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
260 struct gpio_leds_priv *priv;
261 int i, ret = 0;
262
263 if (pdata && pdata->num_leds) {
264 priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, 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