2 * LEDs driver for GPIOs
4 * Copyright (C) 2007 8D Technologies inc.
5 * Raphael Assenat <raph@8d.com>
6 * Copyright (C) 2008 Freescale Semiconductor, Inc.
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.
13 #include <linux/err.h>
14 #include <linux/gpio.h>
15 #include <linux/gpio/consumer.h>
16 #include <linux/kernel.h>
17 #include <linux/leds.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/property.h>
21 #include <linux/slab.h>
22 #include <linux/workqueue.h>
24 struct gpio_led_data
{
25 struct led_classdev cdev
;
26 struct gpio_desc
*gpiod
;
27 struct work_struct work
;
31 int (*platform_gpio_blink_set
)(struct gpio_desc
*desc
, int state
,
32 unsigned long *delay_on
, unsigned long *delay_off
);
35 static void gpio_led_work(struct work_struct
*work
)
37 struct gpio_led_data
*led_dat
=
38 container_of(work
, struct gpio_led_data
, work
);
40 if (led_dat
->blinking
) {
41 led_dat
->platform_gpio_blink_set(led_dat
->gpiod
,
42 led_dat
->new_level
, NULL
, NULL
);
43 led_dat
->blinking
= 0;
45 gpiod_set_value_cansleep(led_dat
->gpiod
, led_dat
->new_level
);
48 static void gpio_led_set(struct led_classdev
*led_cdev
,
49 enum led_brightness value
)
51 struct gpio_led_data
*led_dat
=
52 container_of(led_cdev
, struct gpio_led_data
, cdev
);
60 /* Setting GPIOs with I2C/etc requires a task context, and we don't
61 * seem to have a reliable way to know if we're already in one; so
62 * let's just assume the worst.
64 if (led_dat
->can_sleep
) {
65 led_dat
->new_level
= level
;
66 schedule_work(&led_dat
->work
);
68 if (led_dat
->blinking
) {
69 led_dat
->platform_gpio_blink_set(led_dat
->gpiod
, level
,
71 led_dat
->blinking
= 0;
73 gpiod_set_value(led_dat
->gpiod
, level
);
77 static int gpio_blink_set(struct led_classdev
*led_cdev
,
78 unsigned long *delay_on
, unsigned long *delay_off
)
80 struct gpio_led_data
*led_dat
=
81 container_of(led_cdev
, struct gpio_led_data
, cdev
);
83 led_dat
->blinking
= 1;
84 return led_dat
->platform_gpio_blink_set(led_dat
->gpiod
, GPIO_LED_BLINK
,
88 static int create_gpio_led(const struct gpio_led
*template,
89 struct gpio_led_data
*led_dat
, struct device
*parent
,
90 int (*blink_set
)(struct gpio_desc
*, int, unsigned long *,
95 led_dat
->gpiod
= template->gpiod
;
96 if (!led_dat
->gpiod
) {
98 * This is the legacy code path for platform code that
99 * still uses GPIO numbers. Ultimately we would like to get
100 * rid of this block completely.
102 unsigned long flags
= 0;
104 /* skip leds that aren't available */
105 if (!gpio_is_valid(template->gpio
)) {
106 dev_info(parent
, "Skipping unavailable LED gpio %d (%s)\n",
107 template->gpio
, template->name
);
111 if (template->active_low
)
112 flags
|= GPIOF_ACTIVE_LOW
;
114 ret
= devm_gpio_request_one(parent
, template->gpio
, flags
,
119 led_dat
->gpiod
= gpio_to_desc(template->gpio
);
120 if (IS_ERR(led_dat
->gpiod
))
121 return PTR_ERR(led_dat
->gpiod
);
124 led_dat
->cdev
.name
= template->name
;
125 led_dat
->cdev
.default_trigger
= template->default_trigger
;
126 led_dat
->can_sleep
= gpiod_cansleep(led_dat
->gpiod
);
127 led_dat
->blinking
= 0;
129 led_dat
->platform_gpio_blink_set
= blink_set
;
130 led_dat
->cdev
.blink_set
= gpio_blink_set
;
132 led_dat
->cdev
.brightness_set
= gpio_led_set
;
133 if (template->default_state
== LEDS_GPIO_DEFSTATE_KEEP
)
134 state
= !!gpiod_get_value_cansleep(led_dat
->gpiod
);
136 state
= (template->default_state
== LEDS_GPIO_DEFSTATE_ON
);
137 led_dat
->cdev
.brightness
= state
? LED_FULL
: LED_OFF
;
138 if (!template->retain_state_suspended
)
139 led_dat
->cdev
.flags
|= LED_CORE_SUSPENDRESUME
;
141 ret
= gpiod_direction_output(led_dat
->gpiod
, state
);
145 INIT_WORK(&led_dat
->work
, gpio_led_work
);
147 return led_classdev_register(parent
, &led_dat
->cdev
);
150 static void delete_gpio_led(struct gpio_led_data
*led
)
152 led_classdev_unregister(&led
->cdev
);
153 cancel_work_sync(&led
->work
);
156 struct gpio_leds_priv
{
158 struct gpio_led_data leds
[];
161 static inline int sizeof_gpio_leds_priv(int num_leds
)
163 return sizeof(struct gpio_leds_priv
) +
164 (sizeof(struct gpio_led_data
) * num_leds
);
167 static struct gpio_leds_priv
*gpio_leds_create(struct platform_device
*pdev
)
169 struct device
*dev
= &pdev
->dev
;
170 struct fwnode_handle
*child
;
171 struct gpio_leds_priv
*priv
;
173 struct device_node
*np
;
175 count
= device_get_child_node_count(dev
);
177 return ERR_PTR(-ENODEV
);
179 priv
= devm_kzalloc(dev
, sizeof_gpio_leds_priv(count
), GFP_KERNEL
);
181 return ERR_PTR(-ENOMEM
);
183 device_for_each_child_node(dev
, child
) {
184 struct gpio_led led
= {};
185 const char *state
= NULL
;
187 led
.gpiod
= devm_get_gpiod_from_child(dev
, NULL
, child
);
188 if (IS_ERR(led
.gpiod
)) {
189 fwnode_handle_put(child
);
190 ret
= PTR_ERR(led
.gpiod
);
196 if (fwnode_property_present(child
, "label")) {
197 fwnode_property_read_string(child
, "label", &led
.name
);
199 if (IS_ENABLED(CONFIG_OF
) && !led
.name
&& np
)
202 return ERR_PTR(-EINVAL
);
204 fwnode_property_read_string(child
, "linux,default-trigger",
205 &led
.default_trigger
);
207 if (!fwnode_property_read_string(child
, "default-state",
209 if (!strcmp(state
, "keep"))
210 led
.default_state
= LEDS_GPIO_DEFSTATE_KEEP
;
211 else if (!strcmp(state
, "on"))
212 led
.default_state
= LEDS_GPIO_DEFSTATE_ON
;
214 led
.default_state
= LEDS_GPIO_DEFSTATE_OFF
;
217 if (fwnode_property_present(child
, "retain-state-suspended"))
218 led
.retain_state_suspended
= 1;
220 ret
= create_gpio_led(&led
, &priv
->leds
[priv
->num_leds
++],
223 fwnode_handle_put(child
);
231 for (count
= priv
->num_leds
- 2; count
>= 0; count
--)
232 delete_gpio_led(&priv
->leds
[count
]);
236 static const struct of_device_id of_gpio_leds_match
[] = {
237 { .compatible
= "gpio-leds", },
241 MODULE_DEVICE_TABLE(of
, of_gpio_leds_match
);
243 static int gpio_led_probe(struct platform_device
*pdev
)
245 struct gpio_led_platform_data
*pdata
= dev_get_platdata(&pdev
->dev
);
246 struct gpio_leds_priv
*priv
;
249 if (pdata
&& pdata
->num_leds
) {
250 priv
= devm_kzalloc(&pdev
->dev
,
251 sizeof_gpio_leds_priv(pdata
->num_leds
),
256 priv
->num_leds
= pdata
->num_leds
;
257 for (i
= 0; i
< priv
->num_leds
; i
++) {
258 ret
= create_gpio_led(&pdata
->leds
[i
],
260 &pdev
->dev
, pdata
->gpio_blink_set
);
262 /* On failure: unwind the led creations */
263 for (i
= i
- 1; i
>= 0; i
--)
264 delete_gpio_led(&priv
->leds
[i
]);
269 priv
= gpio_leds_create(pdev
);
271 return PTR_ERR(priv
);
274 platform_set_drvdata(pdev
, priv
);
279 static int gpio_led_remove(struct platform_device
*pdev
)
281 struct gpio_leds_priv
*priv
= platform_get_drvdata(pdev
);
284 for (i
= 0; i
< priv
->num_leds
; i
++)
285 delete_gpio_led(&priv
->leds
[i
]);
290 static struct platform_driver gpio_led_driver
= {
291 .probe
= gpio_led_probe
,
292 .remove
= gpio_led_remove
,
295 .of_match_table
= of_gpio_leds_match
,
299 module_platform_driver(gpio_led_driver
);
301 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
302 MODULE_DESCRIPTION("GPIO LED driver");
303 MODULE_LICENSE("GPL");
304 MODULE_ALIAS("platform:leds-gpio");