1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * LED Flash class interface
4  *
5  * Copyright (C) 2015 Samsung Electronics Co., Ltd.
6  * Author: Jacek Anaszewski <j.anaszewski@samsung.com>
7  */
8 #ifndef __LINUX_FLASH_LEDS_H_INCLUDED
9 #define __LINUX_FLASH_LEDS_H_INCLUDED
10 
11 #include <linux/leds.h>
12 
13 struct device_node;
14 struct led_classdev_flash;
15 
16 /*
17  * Supported led fault bits - must be kept in synch
18  * with V4L2_FLASH_FAULT bits.
19  */
20 #define LED_FAULT_OVER_VOLTAGE		(1 << 0)
21 #define LED_FAULT_TIMEOUT		(1 << 1)
22 #define LED_FAULT_OVER_TEMPERATURE	(1 << 2)
23 #define LED_FAULT_SHORT_CIRCUIT		(1 << 3)
24 #define LED_FAULT_OVER_CURRENT		(1 << 4)
25 #define LED_FAULT_INDICATOR		(1 << 5)
26 #define LED_FAULT_UNDER_VOLTAGE		(1 << 6)
27 #define LED_FAULT_INPUT_VOLTAGE		(1 << 7)
28 #define LED_FAULT_LED_OVER_TEMPERATURE	(1 << 8)
29 #define LED_NUM_FLASH_FAULTS		9
30 
31 #define LED_FLASH_SYSFS_GROUPS_SIZE	5
32 
33 struct led_flash_ops {
34 	/* set flash brightness */
35 	int (*flash_brightness_set)(struct led_classdev_flash *fled_cdev,
36 					u32 brightness);
37 	/* get flash brightness */
38 	int (*flash_brightness_get)(struct led_classdev_flash *fled_cdev,
39 					u32 *brightness);
40 	/* set flash strobe state */
41 	int (*strobe_set)(struct led_classdev_flash *fled_cdev, bool state);
42 	/* get flash strobe state */
43 	int (*strobe_get)(struct led_classdev_flash *fled_cdev, bool *state);
44 	/* set flash timeout */
45 	int (*timeout_set)(struct led_classdev_flash *fled_cdev, u32 timeout);
46 	/* get the flash LED fault */
47 	int (*fault_get)(struct led_classdev_flash *fled_cdev, u32 *fault);
48 };
49 
50 /*
51  * Current value of a flash setting along
52  * with its constraints.
53  */
54 struct led_flash_setting {
55 	/* maximum allowed value */
56 	u32 min;
57 	/* maximum allowed value */
58 	u32 max;
59 	/* step value */
60 	u32 step;
61 	/* current value */
62 	u32 val;
63 };
64 
65 struct led_classdev_flash {
66 	/* led class device */
67 	struct led_classdev led_cdev;
68 
69 	/* flash led specific ops */
70 	const struct led_flash_ops *ops;
71 
72 	/* flash brightness value in microamperes along with its constraints */
73 	struct led_flash_setting brightness;
74 
75 	/* flash timeout value in microseconds along with its constraints */
76 	struct led_flash_setting timeout;
77 
78 	/* LED Flash class sysfs groups */
79 	const struct attribute_group *sysfs_groups[LED_FLASH_SYSFS_GROUPS_SIZE];
80 };
81 
82 static inline struct led_classdev_flash *lcdev_to_flcdev(
83 						struct led_classdev *lcdev)
84 {
85 	return container_of(lcdev, struct led_classdev_flash, led_cdev);
86 }
87 
88 /**
89  * led_classdev_flash_register_ext - register a new object of LED class with
90  *				     init data and with support for flash LEDs
91  * @parent: LED flash controller device this flash LED is driven by
92  * @fled_cdev: the led_classdev_flash structure for this device
93  * @init_data: the LED class flash device initialization data
94  *
95  * Returns: 0 on success or negative error value on failure
96  */
97 extern int led_classdev_flash_register_ext(struct device *parent,
98 					struct led_classdev_flash *fled_cdev,
99 					struct led_init_data *init_data);
100 
101 #define led_classdev_flash_register(parent, fled_cdev)		\
102 	led_classdev_flash_register_ext(parent, fled_cdev, NULL)
103 
104 /**
105  * led_classdev_flash_unregister - unregisters an object of led_classdev class
106  *				   with support for flash LEDs
107  * @fled_cdev: the flash LED to unregister
108  *
109  * Unregister a previously registered via led_classdev_flash_register object
110  */
111 extern void led_classdev_flash_unregister(struct led_classdev_flash *fled_cdev);
112 
113 /**
114  * led_set_flash_strobe - setup flash strobe
115  * @fled_cdev: the flash LED to set strobe on
116  * @state: 1 - strobe flash, 0 - stop flash strobe
117  *
118  * Strobe the flash LED.
119  *
120  * Returns: 0 on success or negative error value on failure
121  */
122 static inline int led_set_flash_strobe(struct led_classdev_flash *fled_cdev,
123 					bool state)
124 {
125 	if (!fled_cdev)
126 		return -EINVAL;
127 	return fled_cdev->ops->strobe_set(fled_cdev, state);
128 }
129 
130 /**
131  * led_get_flash_strobe - get flash strobe status
132  * @fled_cdev: the flash LED to query
133  * @state: 1 - flash is strobing, 0 - flash is off
134  *
135  * Check whether the flash is strobing at the moment.
136  *
137  * Returns: 0 on success or negative error value on failure
138  */
139 static inline int led_get_flash_strobe(struct led_classdev_flash *fled_cdev,
140 					bool *state)
141 {
142 	if (!fled_cdev)
143 		return -EINVAL;
144 	if (fled_cdev->ops->strobe_get)
145 		return fled_cdev->ops->strobe_get(fled_cdev, state);
146 
147 	return -EINVAL;
148 }
149 
150 /**
151  * led_set_flash_brightness - set flash LED brightness
152  * @fled_cdev: the flash LED to set
153  * @brightness: the brightness to set it to
154  *
155  * Set a flash LED's brightness.
156  *
157  * Returns: 0 on success or negative error value on failure
158  */
159 extern int led_set_flash_brightness(struct led_classdev_flash *fled_cdev,
160 					u32 brightness);
161 
162 /**
163  * led_update_flash_brightness - update flash LED brightness
164  * @fled_cdev: the flash LED to query
165  *
166  * Get a flash LED's current brightness and update led_flash->brightness
167  * member with the obtained value.
168  *
169  * Returns: 0 on success or negative error value on failure
170  */
171 extern int led_update_flash_brightness(struct led_classdev_flash *fled_cdev);
172 
173 /**
174  * led_set_flash_timeout - set flash LED timeout
175  * @fled_cdev: the flash LED to set
176  * @timeout: the flash timeout to set it to
177  *
178  * Set the flash strobe duration.
179  *
180  * Returns: 0 on success or negative error value on failure
181  */
182 extern int led_set_flash_timeout(struct led_classdev_flash *fled_cdev,
183 					u32 timeout);
184 
185 /**
186  * led_get_flash_fault - get the flash LED fault
187  * @fled_cdev: the flash LED to query
188  * @fault: bitmask containing flash faults
189  *
190  * Get the flash LED fault.
191  *
192  * Returns: 0 on success or negative error value on failure
193  */
194 extern int led_get_flash_fault(struct led_classdev_flash *fled_cdev,
195 					u32 *fault);
196 
197 #endif	/* __LINUX_FLASH_LEDS_H_INCLUDED */
198