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 #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 */