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
20 struct 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
28 static inline struct gpio_led_data *
cdev_to_gpio_led_data(struct led_classdev * led_cdev)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
gpio_led_set(struct led_classdev * led_cdev,enum led_brightness value)34 static 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
gpio_led_set_blocking(struct led_classdev * led_cdev,enum led_brightness value)57 static 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
gpio_blink_set(struct led_classdev * led_cdev,unsigned long * delay_on,unsigned long * delay_off)64 static 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
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)74 static 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;
100 led_dat->cdev.max_brightness = 1;
101 if (!template->retain_state_suspended)
102 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
103 if (template->panic_indicator)
104 led_dat->cdev.flags |= LED_PANIC_INDICATOR;
105 if (template->retain_state_shutdown)
106 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;
107
108 ret = gpiod_direction_output(led_dat->gpiod, state);
109 if (ret < 0)
110 return ret;
111
112 if (template->name) {
113 led_dat->cdev.name = template->name;
114 ret = devm_led_classdev_register(parent, &led_dat->cdev);
115 } else {
116 init_data.fwnode = fwnode;
117 ret = devm_led_classdev_register_ext(parent, &led_dat->cdev,
118 &init_data);
119 }
120
121 return ret;
122 }
123
124 struct gpio_leds_priv {
125 int num_leds;
126 struct gpio_led_data leds[];
127 };
128
gpio_leds_create(struct platform_device * pdev)129 static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
130 {
131 struct device *dev = &pdev->dev;
132 struct fwnode_handle *child;
133 struct gpio_leds_priv *priv;
134 int count, ret;
135
136 count = device_get_child_node_count(dev);
137 if (!count)
138 return ERR_PTR(-ENODEV);
139
140 priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
141 if (!priv)
142 return ERR_PTR(-ENOMEM);
143
144 device_for_each_child_node(dev, child) {
145 struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];
146 struct gpio_led led = {};
147 const char *state = NULL;
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 if (!fwnode_property_read_string(child, "default-state",
165 &state)) {
166 if (!strcmp(state, "keep"))
167 led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
168 else if (!strcmp(state, "on"))
169 led.default_state = LEDS_GPIO_DEFSTATE_ON;
170 else
171 led.default_state = LEDS_GPIO_DEFSTATE_OFF;
172 }
173
174 if (fwnode_property_present(child, "retain-state-suspended"))
175 led.retain_state_suspended = 1;
176 if (fwnode_property_present(child, "retain-state-shutdown"))
177 led.retain_state_shutdown = 1;
178 if (fwnode_property_present(child, "panic-indicator"))
179 led.panic_indicator = 1;
180
181 ret = create_gpio_led(&led, led_dat, dev, child, NULL);
182 if (ret < 0) {
183 fwnode_handle_put(child);
184 return ERR_PTR(ret);
185 }
186 /* Set gpiod label to match the corresponding LED name. */
187 gpiod_set_consumer_name(led_dat->gpiod,
188 led_dat->cdev.dev->kobj.name);
189 priv->num_leds++;
190 }
191
192 return priv;
193 }
194
195 static const struct of_device_id of_gpio_leds_match[] = {
196 { .compatible = "gpio-leds", },
197 {},
198 };
199
200 MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
201
gpio_led_get_gpiod(struct device * dev,int idx,const struct gpio_led * template)202 static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
203 const struct gpio_led *template)
204 {
205 struct gpio_desc *gpiod;
206 unsigned long flags = GPIOF_OUT_INIT_LOW;
207 int ret;
208
209 /*
210 * This means the LED does not come from the device tree
211 * or ACPI, so let's try just getting it by index from the
212 * device, this will hit the board file, if any and get
213 * the GPIO from there.
214 */
215 gpiod = devm_gpiod_get_index(dev, NULL, idx, GPIOD_OUT_LOW);
216 if (!IS_ERR(gpiod)) {
217 gpiod_set_consumer_name(gpiod, template->name);
218 return gpiod;
219 }
220 if (PTR_ERR(gpiod) != -ENOENT)
221 return gpiod;
222
223 /*
224 * This is the legacy code path for platform code that
225 * still uses GPIO numbers. Ultimately we would like to get
226 * rid of this block completely.
227 */
228
229 /* skip leds that aren't available */
230 if (!gpio_is_valid(template->gpio))
231 return ERR_PTR(-ENOENT);
232
233 if (template->active_low)
234 flags |= GPIOF_ACTIVE_LOW;
235
236 ret = devm_gpio_request_one(dev, template->gpio, flags,
237 template->name);
238 if (ret < 0)
239 return ERR_PTR(ret);
240
241 gpiod = gpio_to_desc(template->gpio);
242 if (!gpiod)
243 return ERR_PTR(-EINVAL);
244
245 return gpiod;
246 }
247
gpio_led_probe(struct platform_device * pdev)248 static int gpio_led_probe(struct platform_device *pdev)
249 {
250 struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
251 struct gpio_leds_priv *priv;
252 int i, ret = 0;
253
254 if (pdata && pdata->num_leds) {
255 priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, pdata->num_leds),
256 GFP_KERNEL);
257 if (!priv)
258 return -ENOMEM;
259
260 priv->num_leds = pdata->num_leds;
261 for (i = 0; i < priv->num_leds; i++) {
262 const struct gpio_led *template = &pdata->leds[i];
263 struct gpio_led_data *led_dat = &priv->leds[i];
264
265 if (template->gpiod)
266 led_dat->gpiod = template->gpiod;
267 else
268 led_dat->gpiod =
269 gpio_led_get_gpiod(&pdev->dev,
270 i, template);
271 if (IS_ERR(led_dat->gpiod)) {
272 dev_info(&pdev->dev, "Skipping unavailable LED gpio %d (%s)\n",
273 template->gpio, template->name);
274 continue;
275 }
276
277 ret = create_gpio_led(template, led_dat,
278 &pdev->dev, NULL,
279 pdata->gpio_blink_set);
280 if (ret < 0)
281 return ret;
282 }
283 } else {
284 priv = gpio_leds_create(pdev);
285 if (IS_ERR(priv))
286 return PTR_ERR(priv);
287 }
288
289 platform_set_drvdata(pdev, priv);
290
291 return 0;
292 }
293
gpio_led_shutdown(struct platform_device * pdev)294 static void gpio_led_shutdown(struct platform_device *pdev)
295 {
296 struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
297 int i;
298
299 for (i = 0; i < priv->num_leds; i++) {
300 struct gpio_led_data *led = &priv->leds[i];
301
302 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
303 gpio_led_set(&led->cdev, LED_OFF);
304 }
305 }
306
307 static struct platform_driver gpio_led_driver = {
308 .probe = gpio_led_probe,
309 .shutdown = gpio_led_shutdown,
310 .driver = {
311 .name = "leds-gpio",
312 .of_match_table = of_gpio_leds_match,
313 },
314 };
315
316 module_platform_driver(gpio_led_driver);
317
318 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
319 MODULE_DESCRIPTION("GPIO LED driver");
320 MODULE_LICENSE("GPL");
321 MODULE_ALIAS("platform:leds-gpio");
322