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(led_dat->gpiod, level);
58		else
59			gpiod_set_value(led_dat->gpiod, 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(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(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(led_dat->gpiod, 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_dat->cdev);
122	} else {
123		init_data.fwnode = fwnode;
124		ret = devm_led_classdev_register_ext(parent, &led_dat->cdev,
125						     &init_data);
126	}
127
128	if (ret)
129		return ret;
130
131	pinctrl = devm_pinctrl_get_select_default(led_dat->cdev.dev);
132	ret = PTR_ERR_OR_ZERO(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(-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			dev_err_probe(dev, PTR_ERR(led.gpiod), "Failed to get GPIO '%pfw'\n",
176				      child);
177			fwnode_handle_put(child);
178			return ERR_CAST(led.gpiod);
179		}
180
181		led_dat->gpiod = led.gpiod;
182
183		led.default_state = led_init_default_state_get(child);
184
185		if (fwnode_property_present(child, "retain-state-suspended"))
186			led.retain_state_suspended = 1;
187		if (fwnode_property_present(child, "retain-state-shutdown"))
188			led.retain_state_shutdown = 1;
189		if (fwnode_property_present(child, "panic-indicator"))
190			led.panic_indicator = 1;
191
192		ret = create_gpio_led(&led, led_dat, dev, child, NULL);
193		if (ret < 0) {
194			fwnode_handle_put(child);
195			return ERR_PTR(ret);
196		}
197		/* Set gpiod label to match the corresponding LED name. */
198		gpiod_set_consumer_name(led_dat->gpiod,
199					led_dat->cdev.dev->kobj.name);
200		priv->num_leds++;
201	}
202
203	return priv;
204}
205
206static const struct of_device_id of_gpio_leds_match[] = {
207	{ .compatible = "gpio-leds", },
208	{},
209};
210
211MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
212
213static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
214					    const struct gpio_led *template)
215{
216	struct gpio_desc *gpiod;
217	unsigned long flags = GPIOF_OUT_INIT_LOW;
218	int ret;
219
220	/*
221	 * This means the LED does not come from the device tree
222	 * or ACPI, so let's try just getting it by index from the
223	 * device, this will hit the board file, if any and get
224	 * the GPIO from there.
225	 */
226	gpiod = devm_gpiod_get_index_optional(dev, NULL, idx, GPIOD_OUT_LOW);
227	if (IS_ERR(gpiod))
228		return gpiod;
229	if (gpiod) {
230		gpiod_set_consumer_name(gpiod, template->name);
231		return gpiod;
232	}
233
234	/*
235	 * This is the legacy code path for platform code that
236	 * still uses GPIO numbers. Ultimately we would like to get
237	 * rid of this block completely.
238	 */
239
240	/* skip leds that aren't available */
241	if (!gpio_is_valid(template->gpio))
242		return ERR_PTR(-ENOENT);
243
244	if (template->active_low)
245		flags |= GPIOF_ACTIVE_LOW;
246
247	ret = devm_gpio_request_one(dev, template->gpio, flags,
248				    template->name);
249	if (ret < 0)
250		return ERR_PTR(ret);
251
252	gpiod = gpio_to_desc(template->gpio);
253	if (!gpiod)
254		return ERR_PTR(-EINVAL);
255
256	return gpiod;
257}
258
259static int gpio_led_probe(struct platform_device *pdev)
260{
261	struct device *dev = &pdev->dev;
262	struct gpio_led_platform_data *pdata = dev_get_platdata(dev);
263	struct gpio_leds_priv *priv;
264	int i, ret;
265
266	if (pdata && pdata->num_leds) {
267		priv = devm_kzalloc(dev, struct_size(priv, leds, pdata->num_leds), GFP_KERNEL);
268		if (!priv)
269			return -ENOMEM;
270
271		priv->num_leds = pdata->num_leds;
272		for (i = 0; i < priv->num_leds; i++) {
273			const struct gpio_led *template = &pdata->leds[i];
274			struct gpio_led_data *led_dat = &priv->leds[i];
275
276			if (template->gpiod)
277				led_dat->gpiod = template->gpiod;
278			else
279				led_dat->gpiod =
280					gpio_led_get_gpiod(dev, i, template);
281			if (IS_ERR(led_dat->gpiod)) {
282				dev_info(dev, "Skipping unavailable LED gpio %d (%s)\n",
283					 template->gpio, template->name);
284				continue;
285			}
286
287			ret = create_gpio_led(template, led_dat, dev, NULL,
288					      pdata->gpio_blink_set);
289			if (ret < 0)
290				return ret;
291		}
292	} else {
293		priv = gpio_leds_create(dev);
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