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1/*
2 * LEDs driver for GPIOs
3 *
4 * Copyright (C) 2007 8D Technologies inc.
5 * Raphael Assenat <raph@8d.com>
6 * Copyright (C) 2008 Freescale Semiconductor, Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 */
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/platform_device.h>
16#include <linux/gpio.h>
17#include <linux/leds.h>
18#include <linux/of_platform.h>
19#include <linux/of_gpio.h>
20#include <linux/slab.h>
21#include <linux/workqueue.h>
22#include <linux/module.h>
23
24struct gpio_led_data {
25 struct led_classdev cdev;
26 unsigned gpio;
27 struct work_struct work;
28 u8 new_level;
29 u8 can_sleep;
30 u8 active_low;
31 u8 blinking;
32 int (*platform_gpio_blink_set)(unsigned gpio, int state,
33 unsigned long *delay_on, unsigned long *delay_off);
34};
35
36static void gpio_led_work(struct work_struct *work)
37{
38 struct gpio_led_data *led_dat =
39 container_of(work, struct gpio_led_data, work);
40
41 if (led_dat->blinking) {
42 led_dat->platform_gpio_blink_set(led_dat->gpio,
43 led_dat->new_level,
44 NULL, NULL);
45 led_dat->blinking = 0;
46 } else
47 gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
48}
49
50static void gpio_led_set(struct led_classdev *led_cdev,
51 enum led_brightness value)
52{
53 struct gpio_led_data *led_dat =
54 container_of(led_cdev, struct gpio_led_data, cdev);
55 int level;
56
57 if (value == LED_OFF)
58 level = 0;
59 else
60 level = 1;
61
62 if (led_dat->active_low)
63 level = !level;
64
65 /* Setting GPIOs with I2C/etc requires a task context, and we don't
66 * seem to have a reliable way to know if we're already in one; so
67 * let's just assume the worst.
68 */
69 if (led_dat->can_sleep) {
70 led_dat->new_level = level;
71 schedule_work(&led_dat->work);
72 } else {
73 if (led_dat->blinking) {
74 led_dat->platform_gpio_blink_set(led_dat->gpio, level,
75 NULL, NULL);
76 led_dat->blinking = 0;
77 } else
78 gpio_set_value(led_dat->gpio, level);
79 }
80}
81
82static int gpio_blink_set(struct led_classdev *led_cdev,
83 unsigned long *delay_on, unsigned long *delay_off)
84{
85 struct gpio_led_data *led_dat =
86 container_of(led_cdev, struct gpio_led_data, cdev);
87
88 led_dat->blinking = 1;
89 return led_dat->platform_gpio_blink_set(led_dat->gpio, GPIO_LED_BLINK,
90 delay_on, delay_off);
91}
92
93static int __devinit create_gpio_led(const struct gpio_led *template,
94 struct gpio_led_data *led_dat, struct device *parent,
95 int (*blink_set)(unsigned, int, unsigned long *, unsigned long *))
96{
97 int ret, state;
98
99 led_dat->gpio = -1;
100
101 /* skip leds that aren't available */
102 if (!gpio_is_valid(template->gpio)) {
103 printk(KERN_INFO "Skipping unavailable LED gpio %d (%s)\n",
104 template->gpio, template->name);
105 return 0;
106 }
107
108 ret = gpio_request(template->gpio, template->name);
109 if (ret < 0)
110 return ret;
111
112 led_dat->cdev.name = template->name;
113 led_dat->cdev.default_trigger = template->default_trigger;
114 led_dat->gpio = template->gpio;
115 led_dat->can_sleep = gpio_cansleep(template->gpio);
116 led_dat->active_low = template->active_low;
117 led_dat->blinking = 0;
118 if (blink_set) {
119 led_dat->platform_gpio_blink_set = blink_set;
120 led_dat->cdev.blink_set = gpio_blink_set;
121 }
122 led_dat->cdev.brightness_set = gpio_led_set;
123 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
124 state = !!gpio_get_value_cansleep(led_dat->gpio) ^ led_dat->active_low;
125 else
126 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
127 led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
128 if (!template->retain_state_suspended)
129 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
130
131 ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state);
132 if (ret < 0)
133 goto err;
134
135 INIT_WORK(&led_dat->work, gpio_led_work);
136
137 ret = led_classdev_register(parent, &led_dat->cdev);
138 if (ret < 0)
139 goto err;
140
141 return 0;
142err:
143 gpio_free(led_dat->gpio);
144 return ret;
145}
146
147static void delete_gpio_led(struct gpio_led_data *led)
148{
149 if (!gpio_is_valid(led->gpio))
150 return;
151 led_classdev_unregister(&led->cdev);
152 cancel_work_sync(&led->work);
153 gpio_free(led->gpio);
154}
155
156struct gpio_leds_priv {
157 int num_leds;
158 struct gpio_led_data leds[];
159};
160
161static inline int sizeof_gpio_leds_priv(int num_leds)
162{
163 return sizeof(struct gpio_leds_priv) +
164 (sizeof(struct gpio_led_data) * num_leds);
165}
166
167/* Code to create from OpenFirmware platform devices */
168#ifdef CONFIG_OF_GPIO
169static struct gpio_leds_priv * __devinit gpio_leds_create_of(struct platform_device *pdev)
170{
171 struct device_node *np = pdev->dev.of_node, *child;
172 struct gpio_leds_priv *priv;
173 int count = 0, ret;
174
175 /* count LEDs in this device, so we know how much to allocate */
176 for_each_child_of_node(np, child)
177 count++;
178 if (!count)
179 return NULL;
180
181 priv = kzalloc(sizeof_gpio_leds_priv(count), GFP_KERNEL);
182 if (!priv)
183 return NULL;
184
185 for_each_child_of_node(np, child) {
186 struct gpio_led led = {};
187 enum of_gpio_flags flags;
188 const char *state;
189
190 led.gpio = of_get_gpio_flags(child, 0, &flags);
191 led.active_low = flags & OF_GPIO_ACTIVE_LOW;
192 led.name = of_get_property(child, "label", NULL) ? : child->name;
193 led.default_trigger =
194 of_get_property(child, "linux,default-trigger", NULL);
195 state = of_get_property(child, "default-state", NULL);
196 if (state) {
197 if (!strcmp(state, "keep"))
198 led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
199 else if (!strcmp(state, "on"))
200 led.default_state = LEDS_GPIO_DEFSTATE_ON;
201 else
202 led.default_state = LEDS_GPIO_DEFSTATE_OFF;
203 }
204
205 ret = create_gpio_led(&led, &priv->leds[priv->num_leds++],
206 &pdev->dev, NULL);
207 if (ret < 0) {
208 of_node_put(child);
209 goto err;
210 }
211 }
212
213 return priv;
214
215err:
216 for (count = priv->num_leds - 2; count >= 0; count--)
217 delete_gpio_led(&priv->leds[count]);
218 kfree(priv);
219 return NULL;
220}
221
222static const struct of_device_id of_gpio_leds_match[] = {
223 { .compatible = "gpio-leds", },
224 {},
225};
226#else /* CONFIG_OF_GPIO */
227static struct gpio_leds_priv * __devinit gpio_leds_create_of(struct platform_device *pdev)
228{
229 return NULL;
230}
231#define of_gpio_leds_match NULL
232#endif /* CONFIG_OF_GPIO */
233
234
235static int __devinit gpio_led_probe(struct platform_device *pdev)
236{
237 struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
238 struct gpio_leds_priv *priv;
239 int i, ret = 0;
240
241 if (pdata && pdata->num_leds) {
242 priv = kzalloc(sizeof_gpio_leds_priv(pdata->num_leds),
243 GFP_KERNEL);
244 if (!priv)
245 return -ENOMEM;
246
247 priv->num_leds = pdata->num_leds;
248 for (i = 0; i < priv->num_leds; i++) {
249 ret = create_gpio_led(&pdata->leds[i],
250 &priv->leds[i],
251 &pdev->dev, pdata->gpio_blink_set);
252 if (ret < 0) {
253 /* On failure: unwind the led creations */
254 for (i = i - 1; i >= 0; i--)
255 delete_gpio_led(&priv->leds[i]);
256 kfree(priv);
257 return ret;
258 }
259 }
260 } else {
261 priv = gpio_leds_create_of(pdev);
262 if (!priv)
263 return -ENODEV;
264 }
265
266 platform_set_drvdata(pdev, priv);
267
268 return 0;
269}
270
271static int __devexit gpio_led_remove(struct platform_device *pdev)
272{
273 struct gpio_leds_priv *priv = dev_get_drvdata(&pdev->dev);
274 int i;
275
276 for (i = 0; i < priv->num_leds; i++)
277 delete_gpio_led(&priv->leds[i]);
278
279 dev_set_drvdata(&pdev->dev, NULL);
280 kfree(priv);
281
282 return 0;
283}
284
285static struct platform_driver gpio_led_driver = {
286 .probe = gpio_led_probe,
287 .remove = __devexit_p(gpio_led_remove),
288 .driver = {
289 .name = "leds-gpio",
290 .owner = THIS_MODULE,
291 .of_match_table = of_gpio_leds_match,
292 },
293};
294
295module_platform_driver(gpio_led_driver);
296
297MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
298MODULE_DESCRIPTION("GPIO LED driver");
299MODULE_LICENSE("GPL");
300MODULE_ALIAS("platform:leds-gpio");
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
20struct 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
28static inline struct gpio_led_data *
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
34static 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
57static 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
64static 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
74static 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
124struct gpio_leds_priv {
125 int num_leds;
126 struct gpio_led_data leds[];
127};
128
129static 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
195static const struct of_device_id of_gpio_leds_match[] = {
196 { .compatible = "gpio-leds", },
197 {},
198};
199
200MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
201
202static 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
248static 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
294static 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
307static 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
316module_platform_driver(gpio_led_driver);
317
318MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
319MODULE_DESCRIPTION("GPIO LED driver");
320MODULE_LICENSE("GPL");
321MODULE_ALIAS("platform:leds-gpio");