xref: /openbmc/linux/drivers/leds/leds-gpio.c (revision 2d618014)
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