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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 #include "leds.h"
20 
21 struct gpio_led_data {
22 	struct led_classdev cdev;
23 	struct gpio_desc *gpiod;
24 	u8 can_sleep;
25 	u8 blinking;
26 	gpio_blink_set_t platform_gpio_blink_set;
27 };
28 
29 static inline struct gpio_led_data *
cdev_to_gpio_led_data(struct led_classdev * led_cdev)30 			cdev_to_gpio_led_data(struct led_classdev *led_cdev)
31 {
32 	return container_of(led_cdev, struct gpio_led_data, cdev);
33 }
34 
gpio_led_set(struct led_classdev * led_cdev,enum led_brightness value)35 static void gpio_led_set(struct led_classdev *led_cdev,
36 	enum led_brightness value)
37 {
38 	struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
39 	int level;
40 
41 	if (value == LED_OFF)
42 		level = 0;
43 	else
44 		level = 1;
45 
46 	if (led_dat->blinking) {
47 		led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
48 						 NULL, NULL);
49 		led_dat->blinking = 0;
50 	} else {
51 		if (led_dat->can_sleep)
52 			gpiod_set_value_cansleep(led_dat->gpiod, level);
53 		else
54 			gpiod_set_value(led_dat->gpiod, level);
55 	}
56 }
57 
gpio_led_set_blocking(struct led_classdev * led_cdev,enum led_brightness value)58 static int gpio_led_set_blocking(struct led_classdev *led_cdev,
59 	enum led_brightness value)
60 {
61 	gpio_led_set(led_cdev, value);
62 	return 0;
63 }
64 
gpio_blink_set(struct led_classdev * led_cdev,unsigned long * delay_on,unsigned long * delay_off)65 static int gpio_blink_set(struct led_classdev *led_cdev,
66 	unsigned long *delay_on, unsigned long *delay_off)
67 {
68 	struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
69 
70 	led_dat->blinking = 1;
71 	return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
72 						delay_on, delay_off);
73 }
74 
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)75 static int create_gpio_led(const struct gpio_led *template,
76 	struct gpio_led_data *led_dat, struct device *parent,
77 	struct fwnode_handle *fwnode, gpio_blink_set_t blink_set)
78 {
79 	struct led_init_data init_data = {};
80 	int ret, state;
81 
82 	led_dat->cdev.default_trigger = template->default_trigger;
83 	led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
84 	if (!led_dat->can_sleep)
85 		led_dat->cdev.brightness_set = gpio_led_set;
86 	else
87 		led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;
88 	led_dat->blinking = 0;
89 	if (blink_set) {
90 		led_dat->platform_gpio_blink_set = blink_set;
91 		led_dat->cdev.blink_set = gpio_blink_set;
92 	}
93 	if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) {
94 		state = gpiod_get_value_cansleep(led_dat->gpiod);
95 		if (state < 0)
96 			return state;
97 	} else {
98 		state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
99 	}
100 	led_dat->cdev.brightness = state;
101 	led_dat->cdev.max_brightness = 1;
102 	if (!template->retain_state_suspended)
103 		led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
104 	if (template->panic_indicator)
105 		led_dat->cdev.flags |= LED_PANIC_INDICATOR;
106 	if (template->retain_state_shutdown)
107 		led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;
108 
109 	ret = gpiod_direction_output(led_dat->gpiod, state);
110 	if (ret < 0)
111 		return ret;
112 
113 	if (template->name) {
114 		led_dat->cdev.name = template->name;
115 		ret = devm_led_classdev_register(parent, &led_dat->cdev);
116 	} else {
117 		init_data.fwnode = fwnode;
118 		ret = devm_led_classdev_register_ext(parent, &led_dat->cdev,
119 						     &init_data);
120 	}
121 
122 	return ret;
123 }
124 
125 struct gpio_leds_priv {
126 	int num_leds;
127 	struct gpio_led_data leds[];
128 };
129 
gpio_leds_create(struct platform_device * pdev)130 static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
131 {
132 	struct device *dev = &pdev->dev;
133 	struct fwnode_handle *child;
134 	struct gpio_leds_priv *priv;
135 	int count, ret;
136 
137 	count = device_get_child_node_count(dev);
138 	if (!count)
139 		return ERR_PTR(-ENODEV);
140 
141 	priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
142 	if (!priv)
143 		return ERR_PTR(-ENOMEM);
144 
145 	device_for_each_child_node(dev, child) {
146 		struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];
147 		struct gpio_led led = {};
148 
149 		/*
150 		 * Acquire gpiod from DT with uninitialized label, which
151 		 * will be updated after LED class device is registered,
152 		 * Only then the final LED name is known.
153 		 */
154 		led.gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL, child,
155 							     GPIOD_ASIS,
156 							     NULL);
157 		if (IS_ERR(led.gpiod)) {
158 			fwnode_handle_put(child);
159 			return ERR_CAST(led.gpiod);
160 		}
161 
162 		led_dat->gpiod = led.gpiod;
163 
164 		led.default_state = led_init_default_state_get(child);
165 
166 		if (fwnode_property_present(child, "retain-state-suspended"))
167 			led.retain_state_suspended = 1;
168 		if (fwnode_property_present(child, "retain-state-shutdown"))
169 			led.retain_state_shutdown = 1;
170 		if (fwnode_property_present(child, "panic-indicator"))
171 			led.panic_indicator = 1;
172 
173 		ret = create_gpio_led(&led, led_dat, dev, child, NULL);
174 		if (ret < 0) {
175 			fwnode_handle_put(child);
176 			return ERR_PTR(ret);
177 		}
178 		/* Set gpiod label to match the corresponding LED name. */
179 		gpiod_set_consumer_name(led_dat->gpiod,
180 					led_dat->cdev.dev->kobj.name);
181 		priv->num_leds++;
182 	}
183 
184 	return priv;
185 }
186 
187 static const struct of_device_id of_gpio_leds_match[] = {
188 	{ .compatible = "gpio-leds", },
189 	{},
190 };
191 
192 MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
193 
gpio_led_get_gpiod(struct device * dev,int idx,const struct gpio_led * template)194 static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
195 					    const struct gpio_led *template)
196 {
197 	struct gpio_desc *gpiod;
198 	unsigned long flags = GPIOF_OUT_INIT_LOW;
199 	int ret;
200 
201 	/*
202 	 * This means the LED does not come from the device tree
203 	 * or ACPI, so let's try just getting it by index from the
204 	 * device, this will hit the board file, if any and get
205 	 * the GPIO from there.
206 	 */
207 	gpiod = devm_gpiod_get_index(dev, NULL, idx, GPIOD_OUT_LOW);
208 	if (!IS_ERR(gpiod)) {
209 		gpiod_set_consumer_name(gpiod, template->name);
210 		return gpiod;
211 	}
212 	if (PTR_ERR(gpiod) != -ENOENT)
213 		return gpiod;
214 
215 	/*
216 	 * This is the legacy code path for platform code that
217 	 * still uses GPIO numbers. Ultimately we would like to get
218 	 * rid of this block completely.
219 	 */
220 
221 	/* skip leds that aren't available */
222 	if (!gpio_is_valid(template->gpio))
223 		return ERR_PTR(-ENOENT);
224 
225 	if (template->active_low)
226 		flags |= GPIOF_ACTIVE_LOW;
227 
228 	ret = devm_gpio_request_one(dev, template->gpio, flags,
229 				    template->name);
230 	if (ret < 0)
231 		return ERR_PTR(ret);
232 
233 	gpiod = gpio_to_desc(template->gpio);
234 	if (!gpiod)
235 		return ERR_PTR(-EINVAL);
236 
237 	return gpiod;
238 }
239 
gpio_led_probe(struct platform_device * pdev)240 static int gpio_led_probe(struct platform_device *pdev)
241 {
242 	struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
243 	struct gpio_leds_priv *priv;
244 	int i, ret = 0;
245 
246 	if (pdata && pdata->num_leds) {
247 		priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, pdata->num_leds),
248 				    GFP_KERNEL);
249 		if (!priv)
250 			return -ENOMEM;
251 
252 		priv->num_leds = pdata->num_leds;
253 		for (i = 0; i < priv->num_leds; i++) {
254 			const struct gpio_led *template = &pdata->leds[i];
255 			struct gpio_led_data *led_dat = &priv->leds[i];
256 
257 			if (template->gpiod)
258 				led_dat->gpiod = template->gpiod;
259 			else
260 				led_dat->gpiod =
261 					gpio_led_get_gpiod(&pdev->dev,
262 							   i, template);
263 			if (IS_ERR(led_dat->gpiod)) {
264 				dev_info(&pdev->dev, "Skipping unavailable LED gpio %d (%s)\n",
265 					 template->gpio, template->name);
266 				continue;
267 			}
268 
269 			ret = create_gpio_led(template, led_dat,
270 					      &pdev->dev, NULL,
271 					      pdata->gpio_blink_set);
272 			if (ret < 0)
273 				return ret;
274 		}
275 	} else {
276 		priv = gpio_leds_create(pdev);
277 		if (IS_ERR(priv))
278 			return PTR_ERR(priv);
279 	}
280 
281 	platform_set_drvdata(pdev, priv);
282 
283 	return 0;
284 }
285 
gpio_led_shutdown(struct platform_device * pdev)286 static void gpio_led_shutdown(struct platform_device *pdev)
287 {
288 	struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
289 	int i;
290 
291 	for (i = 0; i < priv->num_leds; i++) {
292 		struct gpio_led_data *led = &priv->leds[i];
293 
294 		if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
295 			gpio_led_set(&led->cdev, LED_OFF);
296 	}
297 }
298 
299 static struct platform_driver gpio_led_driver = {
300 	.probe		= gpio_led_probe,
301 	.shutdown	= gpio_led_shutdown,
302 	.driver		= {
303 		.name	= "leds-gpio",
304 		.of_match_table = of_gpio_leds_match,
305 	},
306 };
307 
308 module_platform_driver(gpio_led_driver);
309 
310 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
311 MODULE_DESCRIPTION("GPIO LED driver");
312 MODULE_LICENSE("GPL");
313 MODULE_ALIAS("platform:leds-gpio");
314