include/linux/led-class-flash.h

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