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/consumer.h>
13 #include <linux/gpio/legacy.h>
14 #include <linux/leds.h>
15 #include <linux/module.h>
16 #include <linux/overflow.h>
17 #include <linux/pinctrl/consumer.h>
18 #include <linux/platform_device.h>
19 #include <linux/property.h>
20 #include <linux/slab.h>
21 #include <linux/types.h>
22
23 struct gpio_led_data {
24 struct led_classdev cdev;
25 struct gpio_desc *gpiod;
26 u8 can_sleep;
27 u8 blinking;
28 gpio_blink_set_t platform_gpio_blink_set;
29 };
30
31 static inline struct gpio_led_data *
cdev_to_gpio_led_data(struct led_classdev * led_cdev)32 cdev_to_gpio_led_data(struct led_classdev *led_cdev)
33 {
34 return container_of(led_cdev, struct gpio_led_data, cdev);
35 }
36
gpio_led_set(struct led_classdev * led_cdev,enum led_brightness value)37 static void gpio_led_set(struct led_classdev *led_cdev,
38 enum led_brightness value)
39 {
40 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
41 int level;
42
43 if (value == LED_OFF)
44 level = 0;
45 else
46 level = 1;
47
48 if (led_dat->blinking) {
49 led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
50 NULL, NULL);
51 led_dat->blinking = 0;
52 } else {
53 if (led_dat->can_sleep)
54 gpiod_set_value_cansleep(led_dat->gpiod, level);
55 else
56 gpiod_set_value(led_dat->gpiod, level);
57 }
58 }
59
gpio_led_set_blocking(struct led_classdev * led_cdev,enum led_brightness value)60 static int gpio_led_set_blocking(struct led_classdev *led_cdev,
61 enum led_brightness value)
62 {
63 gpio_led_set(led_cdev, value);
64 return 0;
65 }
66
gpio_blink_set(struct led_classdev * led_cdev,unsigned long * delay_on,unsigned long * delay_off)67 static int gpio_blink_set(struct led_classdev *led_cdev,
68 unsigned long *delay_on, unsigned long *delay_off)
69 {
70 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
71
72 led_dat->blinking = 1;
73 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
74 delay_on, delay_off);
75 }
76
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)77 static int create_gpio_led(const struct gpio_led *template,
78 struct gpio_led_data *led_dat, struct device *parent,
79 struct fwnode_handle *fwnode, gpio_blink_set_t blink_set)
80 {
81 struct led_init_data init_data = {};
82 struct pinctrl *pinctrl;
83 int ret, state;
84
85 led_dat->cdev.default_trigger = template->default_trigger;
86 led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
87 if (!led_dat->can_sleep)
88 led_dat->cdev.brightness_set = gpio_led_set;
89 else
90 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;
91 led_dat->blinking = 0;
92 if (blink_set) {
93 led_dat->platform_gpio_blink_set = blink_set;
94 led_dat->cdev.blink_set = gpio_blink_set;
95 }
96 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) {
97 state = gpiod_get_value_cansleep(led_dat->gpiod);
98 if (state < 0)
99 return state;
100 } else {
101 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
102 }
103 led_dat->cdev.brightness = state;
104 led_dat->cdev.max_brightness = 1;
105 if (!template->retain_state_suspended)
106 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
107 if (template->panic_indicator)
108 led_dat->cdev.flags |= LED_PANIC_INDICATOR;
109 if (template->retain_state_shutdown)
110 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;
111
112 ret = gpiod_direction_output(led_dat->gpiod, state);
113 if (ret < 0)
114 return ret;
115
116 if (template->name) {
117 led_dat->cdev.name = template->name;
118 ret = devm_led_classdev_register(parent, &led_dat->cdev);
119 } else {
120 init_data.fwnode = fwnode;
121 ret = devm_led_classdev_register_ext(parent, &led_dat->cdev,
122 &init_data);
123 }
124
125 if (ret)
126 return ret;
127
128 pinctrl = devm_pinctrl_get_select_default(led_dat->cdev.dev);
129 ret = PTR_ERR_OR_ZERO(pinctrl);
130 /* pinctrl-%d not present, not an error */
131 if (ret == -ENODEV)
132 ret = 0;
133 if (ret) {
134 dev_warn(led_dat->cdev.dev, "Failed to select %pfw pinctrl: %d\n",
135 fwnode, ret);
136 }
137
138 return ret;
139 }
140
141 struct gpio_leds_priv {
142 int num_leds;
143 struct gpio_led_data leds[] __counted_by(num_leds);
144 };
145
gpio_leds_create(struct device * dev)146 static struct gpio_leds_priv *gpio_leds_create(struct device *dev)
147 {
148 struct gpio_leds_priv *priv;
149 int count, used, ret;
150
151 count = device_get_child_node_count(dev);
152 if (!count)
153 return ERR_PTR(-ENODEV);
154
155 priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
156 if (!priv)
157 return ERR_PTR(-ENOMEM);
158 priv->num_leds = count;
159 used = 0;
160
161 device_for_each_child_node_scoped(dev, child) {
162 struct gpio_led_data *led_dat = &priv->leds[used];
163 struct gpio_led led = {};
164
165 /*
166 * Acquire gpiod from DT with uninitialized label, which
167 * will be updated after LED class device is registered,
168 * Only then the final LED name is known.
169 */
170 led.gpiod = devm_fwnode_gpiod_get(dev, child, NULL, GPIOD_ASIS,
171 NULL);
172 if (IS_ERR(led.gpiod)) {
173 dev_err_probe(dev, PTR_ERR(led.gpiod), "Failed to get GPIO '%pfw'\n",
174 child);
175 return ERR_CAST(led.gpiod);
176 }
177
178 led_dat->gpiod = led.gpiod;
179
180 led.default_state = led_init_default_state_get(child);
181
182 if (fwnode_property_present(child, "retain-state-suspended"))
183 led.retain_state_suspended = 1;
184 if (fwnode_property_present(child, "retain-state-shutdown"))
185 led.retain_state_shutdown = 1;
186 if (fwnode_property_present(child, "panic-indicator"))
187 led.panic_indicator = 1;
188
189 ret = create_gpio_led(&led, led_dat, dev, child, NULL);
190 if (ret < 0)
191 return ERR_PTR(ret);
192
193 /* Set gpiod label to match the corresponding LED name. */
194 gpiod_set_consumer_name(led_dat->gpiod,
195 led_dat->cdev.dev->kobj.name);
196 used++;
197 }
198 priv->num_leds = used;
199
200 return priv;
201 }
202
203 static const struct of_device_id of_gpio_leds_match[] = {
204 { .compatible = "gpio-leds", },
205 {},
206 };
207
208 MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
209
gpio_led_get_gpiod(struct device * dev,int idx,const struct gpio_led * template)210 static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
211 const struct gpio_led *template)
212 {
213 struct gpio_desc *gpiod;
214
215 /*
216 * This means the LED does not come from the device tree
217 * or ACPI, so let's try just getting it by index from the
218 * device, this will hit the board file, if any and get
219 * the GPIO from there.
220 */
221 gpiod = devm_gpiod_get_index_optional(dev, NULL, idx, GPIOD_OUT_LOW);
222 if (IS_ERR(gpiod))
223 return gpiod;
224
225 gpiod_set_consumer_name(gpiod, template->name);
226 return gpiod;
227 }
228
229 #ifdef CONFIG_GPIOLIB_LEGACY
230 /*
231 * This is the legacy code path for platform code that still uses
232 * GPIO numbers, mainly MIPS and SuperH board files.
233 * Ultimately we would like to get rid of this block completely.
234 *
235 * ppc44x-warp sets the template->gpiod directly instead of
236 * adding a lookup table or device properties. This is not
237 * much better.
238 */
gpio_led_get_legacy_gpiod(struct device * dev,int idx,const struct gpio_led * template)239 static struct gpio_desc *gpio_led_get_legacy_gpiod(struct device *dev, int idx,
240 const struct gpio_led *template)
241 {
242 struct gpio_desc *gpiod;
243 int ret;
244
245 if (template->gpiod)
246 return template->gpiod;
247
248 /* skip leds that aren't available */
249 if (!gpio_is_valid(template->gpio))
250 return ERR_PTR(-ENOENT);
251
252 ret = devm_gpio_request_one(dev, template->gpio, GPIOF_OUT_INIT_LOW,
253 template->name);
254 if (ret < 0)
255 return ERR_PTR(ret);
256
257 gpiod = gpio_to_desc(template->gpio);
258 if (!gpiod)
259 return ERR_PTR(-EINVAL);
260
261 if (template->active_low ^ gpiod_is_active_low(gpiod))
262 gpiod_toggle_active_low(gpiod);
263
264 return gpiod;
265 }
266 #else
gpio_led_get_legacy_gpiod(struct device * dev,int idx,const struct gpio_led * template)267 static struct gpio_desc *gpio_led_get_legacy_gpiod(struct device *dev, int idx,
268 const struct gpio_led *template)
269 {
270 return template->gpiod ?: ERR_PTR(-ENOENT);
271 }
272 #endif
273
gpio_led_probe(struct platform_device * pdev)274 static int gpio_led_probe(struct platform_device *pdev)
275 {
276 struct device *dev = &pdev->dev;
277 struct gpio_led_platform_data *pdata = dev_get_platdata(dev);
278 struct gpio_leds_priv *priv;
279 int i, ret;
280
281 if (pdata && pdata->num_leds) {
282 priv = devm_kzalloc(dev, struct_size(priv, leds, pdata->num_leds), GFP_KERNEL);
283 if (!priv)
284 return -ENOMEM;
285
286 priv->num_leds = pdata->num_leds;
287 for (i = 0; i < priv->num_leds; i++) {
288 const struct gpio_led *template = &pdata->leds[i];
289 struct gpio_led_data *led_dat = &priv->leds[i];
290
291 led_dat->gpiod = gpio_led_get_gpiod(dev, i, template);
292 if (!led_dat->gpiod)
293 led_dat->gpiod =
294 gpio_led_get_legacy_gpiod(dev, i, template);
295 if (IS_ERR(led_dat->gpiod)) {
296 dev_info(dev, "Skipping unavailable LED gpio %s\n",
297 template->name);
298 led_dat->gpiod = NULL;
299 continue;
300 }
301
302 ret = create_gpio_led(template, led_dat, dev, NULL,
303 pdata->gpio_blink_set);
304 if (ret < 0)
305 return ret;
306 }
307 } else {
308 priv = gpio_leds_create(dev);
309 if (IS_ERR(priv))
310 return PTR_ERR(priv);
311 }
312
313 platform_set_drvdata(pdev, priv);
314
315 return 0;
316 }
317
gpio_led_shutdown(struct platform_device * pdev)318 static void gpio_led_shutdown(struct platform_device *pdev)
319 {
320 struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
321 int i;
322
323 for (i = 0; i < priv->num_leds; i++) {
324 struct gpio_led_data *led = &priv->leds[i];
325
326 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
327 gpio_led_set(&led->cdev, LED_OFF);
328 }
329 }
330
331 static struct platform_driver gpio_led_driver = {
332 .probe = gpio_led_probe,
333 .shutdown = gpio_led_shutdown,
334 .driver = {
335 .name = "leds-gpio",
336 .of_match_table = of_gpio_leds_match,
337 },
338 };
339
340 module_platform_driver(gpio_led_driver);
341
342 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
343 MODULE_DESCRIPTION("GPIO LED driver");
344 MODULE_LICENSE("GPL");
345 MODULE_ALIAS("platform:leds-gpio");
346