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
26 struct 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
34 static inline struct gpio_led_data *
cdev_to_gpio_led_data(struct led_classdev * led_cdev)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
gpio_led_set(struct led_classdev * led_cdev,enum led_brightness value)40 static 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
gpio_led_set_blocking(struct led_classdev * led_cdev,enum led_brightness value)63 static 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
gpio_blink_set(struct led_classdev * led_cdev,unsigned long * delay_on,unsigned long * delay_off)70 static 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
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)80 static 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
144 struct gpio_leds_priv {
145 int num_leds;
146 struct gpio_led_data leds[] __counted_by(num_leds);
147 };
148
gpio_leds_create(struct device * dev)149 static 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
206 static const struct of_device_id of_gpio_leds_match[] = {
207 { .compatible = "gpio-leds", },
208 {},
209 };
210
211 MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
212
gpio_led_get_gpiod(struct device * dev,int idx,const struct gpio_led * template)213 static 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
gpio_led_probe(struct platform_device * pdev)259 static 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
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