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