/*
   * Copyright (C) 2015 Thomas Chou <thomas@wytron.com.tw>
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #ifndef _TIMER_H_
  #define _TIMER_H_
  
  /*

   * dm_timer_init - initialize a timer for time keeping. On success
   * initializes gd->timer so that lib/timer can use it for future
   * referrence.
   *
   * @return - 0 on success or error number
   */
  int dm_timer_init(void);
  
  /*

   * timer_conv_64 - convert 32-bit counter value to 64-bit
   *
   * @count: 32-bit counter value
   * @return: 64-bit counter value
   */
  u64 timer_conv_64(u32 count);
  
  /*

   * Get the current timer count
   *

   * @dev: The timer device

   * @count: pointer that returns the current timer count
   * @return: 0 if OK, -ve on error
   */

  int timer_get_count(struct udevice *dev, u64 *count);

  /*
   * Get the timer input clock frequency
   *

   * @dev: The timer device

   * @return: the timer input clock frequency
   */
  unsigned long timer_get_rate(struct udevice *dev);
  
  /*

   * struct timer_ops - Driver model timer operations

   *

   * The uclass interface is implemented by all timer devices which use

   * driver model.
   */
  struct timer_ops {
  	/*
  	 * Get the current timer count
  	 *

  	 * @dev: The timer device

  	 * @count: pointer that returns the current 64-bit timer count

  	 * @return: 0 if OK, -ve on error
  	 */

  	int (*get_count)(struct udevice *dev, u64 *count);

  };
  
  /*
   * struct timer_dev_priv - information about a device used by the uclass
   *
   * @clock_rate: the timer input clock frequency
   */
  struct timer_dev_priv {
  	unsigned long clock_rate;
  };

  /**
   * timer_early_get_count() - Implement timer_get_count() before driver model
   *
   * If CONFIG_TIMER_EARLY is enabled, this function wil be called to return
   * the current timer value before the proper driver model timer is ready.
   * It should be implemented by one of the timer values. This is mostly useful
   * for tracing.
   */
  u64 timer_early_get_count(void);
  
  /**
   * timer_early_get_rate() - Get the timer rate before driver model
   *
   * If CONFIG_TIMER_EARLY is enabled, this function wil be called to return
   * the current timer rate in Hz before the proper driver model timer is ready.
   * It should be implemented by one of the timer values. This is mostly useful
   * for tracing. This corresponds to the clock_rate value in struct
   * timer_dev_priv.
   */
  unsigned long timer_early_get_rate(void);

  #endif	/* _TIMER_H_ */