include/linux/led-class-flash.h

   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 - register a new object of led_classdev class
  90  *                               with support for flash LEDs
  91  * @parent: the flash LED to register
  92  * @fled_cdev: the led_classdev_flash structure for this device
  93  *
  94  * Returns: 0 on success or negative error value on failure
  95  */
  96 extern int led_classdev_flash_register(struct device *parent,
  97                                 struct led_classdev_flash *fled_cdev);
  98
  99 /**
 100  * led_classdev_flash_unregister - unregisters an object of led_classdev class
 101  *                                 with support for flash LEDs
 102  * @fled_cdev: the flash LED to unregister
 103  *
 104  * Unregister a previously registered via led_classdev_flash_register object
 105  */
 106 extern void led_classdev_flash_unregister(struct led_classdev_flash *fled_cdev);
 107
 108 /**
 109  * led_set_flash_strobe - setup flash strobe
 110  * @fled_cdev: the flash LED to set strobe on
 111  * @state: 1 - strobe flash, 0 - stop flash strobe
 112  *
 113  * Strobe the flash LED.
 114  *
 115  * Returns: 0 on success or negative error value on failure
 116  */
 117 static inline int led_set_flash_strobe(struct led_classdev_flash *fled_cdev,
 118                                         bool state)
 119 {
 120         if (!fled_cdev)
 121                 return -EINVAL;
 122         return fled_cdev->ops->strobe_set(fled_cdev, state);
 123 }
 124
 125 /**
 126  * led_get_flash_strobe - get flash strobe status
 127  * @fled_cdev: the flash LED to query
 128  * @state: 1 - flash is strobing, 0 - flash is off
 129  *
 130  * Check whether the flash is strobing at the moment.
 131  *
 132  * Returns: 0 on success or negative error value on failure
 133  */
 134 static inline int led_get_flash_strobe(struct led_classdev_flash *fled_cdev,
 135                                         bool *state)
 136 {
 137         if (!fled_cdev)
 138                 return -EINVAL;
 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 */