1 /* 2 * LED Flash class interface 3 * 4 * Copyright (C) 2015 Samsung Electronics Co., Ltd. 5 * Author: Jacek Anaszewski <j.anaszewski@samsung.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 */ 12 #ifndef __LINUX_FLASH_LEDS_H_INCLUDED 13 #define __LINUX_FLASH_LEDS_H_INCLUDED 14 15 #include <linux/leds.h> 16 #include <uapi/linux/v4l2-controls.h> 17 18 struct device_node; 19 struct led_classdev_flash; 20 21 /* 22 * Supported led fault bits - must be kept in synch 23 * with V4L2_FLASH_FAULT bits. 24 */ 25 #define LED_FAULT_OVER_VOLTAGE (1 << 0) 26 #define LED_FAULT_TIMEOUT (1 << 1) 27 #define LED_FAULT_OVER_TEMPERATURE (1 << 2) 28 #define LED_FAULT_SHORT_CIRCUIT (1 << 3) 29 #define LED_FAULT_OVER_CURRENT (1 << 4) 30 #define LED_FAULT_INDICATOR (1 << 5) 31 #define LED_FAULT_UNDER_VOLTAGE (1 << 6) 32 #define LED_FAULT_INPUT_VOLTAGE (1 << 7) 33 #define LED_FAULT_LED_OVER_TEMPERATURE (1 << 8) 34 #define LED_NUM_FLASH_FAULTS 9 35 36 #define LED_FLASH_MAX_SYSFS_GROUPS 7 37 38 struct led_flash_ops { 39 /* set flash brightness */ 40 int (*flash_brightness_set)(struct led_classdev_flash *fled_cdev, 41 u32 brightness); 42 /* get flash brightness */ 43 int (*flash_brightness_get)(struct led_classdev_flash *fled_cdev, 44 u32 *brightness); 45 /* set flash strobe state */ 46 int (*strobe_set)(struct led_classdev_flash *fled_cdev, bool state); 47 /* get flash strobe state */ 48 int (*strobe_get)(struct led_classdev_flash *fled_cdev, bool *state); 49 /* set flash timeout */ 50 int (*timeout_set)(struct led_classdev_flash *fled_cdev, u32 timeout); 51 /* get the flash LED fault */ 52 int (*fault_get)(struct led_classdev_flash *fled_cdev, u32 *fault); 53 }; 54 55 /* 56 * Current value of a flash setting along 57 * with its constraints. 58 */ 59 struct led_flash_setting { 60 /* maximum allowed value */ 61 u32 min; 62 /* maximum allowed value */ 63 u32 max; 64 /* step value */ 65 u32 step; 66 /* current value */ 67 u32 val; 68 }; 69 70 struct led_classdev_flash { 71 /* led class device */ 72 struct led_classdev led_cdev; 73 74 /* flash led specific ops */ 75 const struct led_flash_ops *ops; 76 77 /* flash brightness value in microamperes along with its constraints */ 78 struct led_flash_setting brightness; 79 80 /* flash timeout value in microseconds along with its constraints */ 81 struct led_flash_setting timeout; 82 83 /* LED Flash class sysfs groups */ 84 const struct attribute_group *sysfs_groups[LED_FLASH_MAX_SYSFS_GROUPS]; 85 86 /* LEDs available for flash strobe synchronization */ 87 struct led_classdev_flash **sync_leds; 88 89 /* Number of LEDs available for flash strobe synchronization */ 90 int num_sync_leds; 91 92 /* 93 * The identifier of the sub-led to synchronize the flash strobe with. 94 * Identifiers start from 1, which reflects the first element from the 95 * sync_leds array. 0 means that the flash strobe should not be 96 * synchronized. 97 */ 98 u32 sync_led_id; 99 }; 100 101 static inline struct led_classdev_flash *lcdev_to_flcdev( 102 struct led_classdev *lcdev) 103 { 104 return container_of(lcdev, struct led_classdev_flash, led_cdev); 105 } 106 107 /** 108 * led_classdev_flash_register - register a new object of led_classdev class 109 * with support for flash LEDs 110 * @parent: the flash LED to register 111 * @fled_cdev: the led_classdev_flash structure for this device 112 * 113 * Returns: 0 on success or negative error value on failure 114 */ 115 extern int led_classdev_flash_register(struct device *parent, 116 struct led_classdev_flash *fled_cdev); 117 118 /** 119 * led_classdev_flash_unregister - unregisters an object of led_classdev class 120 * with support for flash LEDs 121 * @fled_cdev: the flash LED to unregister 122 * 123 * Unregister a previously registered via led_classdev_flash_register object 124 */ 125 extern void led_classdev_flash_unregister(struct led_classdev_flash *fled_cdev); 126 127 /** 128 * led_set_flash_strobe - setup flash strobe 129 * @fled_cdev: the flash LED to set strobe on 130 * @state: 1 - strobe flash, 0 - stop flash strobe 131 * 132 * Strobe the flash LED. 133 * 134 * Returns: 0 on success or negative error value on failure 135 */ 136 static inline int led_set_flash_strobe(struct led_classdev_flash *fled_cdev, 137 bool state) 138 { 139 return fled_cdev->ops->strobe_set(fled_cdev, state); 140 } 141 142 /** 143 * led_get_flash_strobe - get flash strobe status 144 * @fled_cdev: the flash LED to query 145 * @state: 1 - flash is strobing, 0 - flash is off 146 * 147 * Check whether the flash is strobing at the moment. 148 * 149 * Returns: 0 on success or negative error value on failure 150 */ 151 static inline int led_get_flash_strobe(struct led_classdev_flash *fled_cdev, 152 bool *state) 153 { 154 if (fled_cdev->ops->strobe_get) 155 return fled_cdev->ops->strobe_get(fled_cdev, state); 156 157 return -EINVAL; 158 } 159 160 /** 161 * led_set_flash_brightness - set flash LED brightness 162 * @fled_cdev: the flash LED to set 163 * @brightness: the brightness to set it to 164 * 165 * Set a flash LED's brightness. 166 * 167 * Returns: 0 on success or negative error value on failure 168 */ 169 extern int led_set_flash_brightness(struct led_classdev_flash *fled_cdev, 170 u32 brightness); 171 172 /** 173 * led_update_flash_brightness - update flash LED brightness 174 * @fled_cdev: the flash LED to query 175 * 176 * Get a flash LED's current brightness and update led_flash->brightness 177 * member with the obtained value. 178 * 179 * Returns: 0 on success or negative error value on failure 180 */ 181 extern int led_update_flash_brightness(struct led_classdev_flash *fled_cdev); 182 183 /** 184 * led_set_flash_timeout - set flash LED timeout 185 * @fled_cdev: the flash LED to set 186 * @timeout: the flash timeout to set it to 187 * 188 * Set the flash strobe duration. 189 * 190 * Returns: 0 on success or negative error value on failure 191 */ 192 extern int led_set_flash_timeout(struct led_classdev_flash *fled_cdev, 193 u32 timeout); 194 195 /** 196 * led_get_flash_fault - get the flash LED fault 197 * @fled_cdev: the flash LED to query 198 * @fault: bitmask containing flash faults 199 * 200 * Get the flash LED fault. 201 * 202 * Returns: 0 on success or negative error value on failure 203 */ 204 extern int led_get_flash_fault(struct led_classdev_flash *fled_cdev, 205 u32 *fault); 206 207 #endif /* __LINUX_FLASH_LEDS_H_INCLUDED */ 208