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
22struct 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
30static inline struct gpio_led_data *
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
36static 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
59static 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
66static 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
76static 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
143struct gpio_leds_priv {
144	int num_leds;
145	struct gpio_led_data leds[];
146};
147
148static 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
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(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
257static 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
303static 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
316static 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
325module_platform_driver(gpio_led_driver);
326
327MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
328MODULE_DESCRIPTION("GPIO LED driver");
329MODULE_LICENSE("GPL");
330MODULE_ALIAS("platform:leds-gpio");
331