1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Copyright (c) 2015 Google, Inc
4  * Written by Simon Glass <sjg@chromium.org>
5  */
6 
7 #ifndef __LED_H
8 #define __LED_H
9 
10 struct udevice;
11 
12 enum led_state_t {
13 	LEDST_OFF = 0,
14 	LEDST_ON = 1,
15 	LEDST_TOGGLE,
16 #ifdef CONFIG_LED_BLINK
17 	LEDST_BLINK,
18 #endif
19 
20 	LEDST_COUNT,
21 };
22 
23 /**
24  * struct led_uc_plat - Platform data the uclass stores about each device
25  *
26  * @label:	LED label
27  * @default_state:	LED default state
28  */
29 struct led_uc_plat {
30 	const char *label;
31 	enum led_state_t default_state;
32 };
33 
34 /**
35  * struct led_uc_priv - Private data the uclass stores about each device
36  *
37  * @period_ms:	Flash period in milliseconds
38  */
39 struct led_uc_priv {
40 	int period_ms;
41 };
42 
43 struct led_ops {
44 	/**
45 	 * set_state() - set the state of an LED
46 	 *
47 	 * @dev:	LED device to change
48 	 * @state:	LED state to set
49 	 * @return 0 if OK, -ve on error
50 	 */
51 	int (*set_state)(struct udevice *dev, enum led_state_t state);
52 
53 	/**
54 	 * led_get_state() - get the state of an LED
55 	 *
56 	 * @dev:	LED device to change
57 	 * @return LED state led_state_t, or -ve on error
58 	 */
59 	enum led_state_t (*get_state)(struct udevice *dev);
60 
61 #ifdef CONFIG_LED_BLINK
62 	/**
63 	 * led_set_period() - set the blink period of an LED
64 	 *
65 	 * Thie records the period if supported, or returns -ENOSYS if not.
66 	 * To start the LED blinking, use set_state().
67 	 *
68 	 * @dev:	LED device to change
69 	 * @period_ms:	LED blink period in milliseconds
70 	 * @return 0 if OK, -ve on error
71 	 */
72 	int (*set_period)(struct udevice *dev, int period_ms);
73 #endif
74 };
75 
76 #define led_get_ops(dev)	((struct led_ops *)(dev)->driver->ops)
77 
78 /**
79  * led_get_by_label() - Find an LED device by label
80  *
81  * @label:	LED label to look up
82  * @devp:	Returns the associated device, if found
83  * Return: 0 if found, -ENODEV if not found, other -ve on error
84  */
85 int led_get_by_label(const char *label, struct udevice **devp);
86 
87 /**
88  * led_set_state() - set the state of an LED
89  *
90  * @dev:	LED device to change
91  * @state:	LED state to set
92  * Return: 0 if OK, -ve on error
93  */
94 int led_set_state(struct udevice *dev, enum led_state_t state);
95 
96 /**
97  * led_get_state() - get the state of an LED
98  *
99  * @dev:	LED device to change
100  * Return: LED state led_state_t, or -ve on error
101  */
102 enum led_state_t led_get_state(struct udevice *dev);
103 
104 /**
105  * led_set_period() - set the blink period of an LED
106  *
107  * @dev:	LED device to change
108  * @period_ms:	LED blink period in milliseconds
109  * Return: 0 if OK, -ve on error
110  */
111 int led_set_period(struct udevice *dev, int period_ms);
112 
113 #endif
114