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 */