include/timer.h

   1 /*
   2  * Copyright (C) 2015 Thomas Chou <thomas@wytron.com.tw>
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #ifndef _TIMER_H_
   8 #define _TIMER_H_
   9
  10 /*
  11  * dm_timer_init - initialize a timer for time keeping. On success
  12  * initializes gd->timer so that lib/timer can use it for future
  13  * referrence.
  14  *
  15  * @return - 0 on success or error number
  16  */
  17 int dm_timer_init(void);
  18
  19 /*
  20  * timer_conv_64 - convert 32-bit counter value to 64-bit
  21  *
  22  * @count: 32-bit counter value
  23  * @return: 64-bit counter value
  24  */
  25 u64 timer_conv_64(u32 count);
  26
  27 /*
  28  * Get the current timer count
  29  *
  30  * @dev: The timer device
  31  * @count: pointer that returns the current timer count
  32  * @return: 0 if OK, -ve on error
  33  */
  34 int timer_get_count(struct udevice *dev, u64 *count);
  35
  36 /*
  37  * Get the timer input clock frequency
  38  *
  39  * @dev: The timer device
  40  * @return: the timer input clock frequency
  41  */
  42 unsigned long timer_get_rate(struct udevice *dev);
  43
  44 /*
  45  * struct timer_ops - Driver model timer operations
  46  *
  47  * The uclass interface is implemented by all timer devices which use
  48  * driver model.
  49  */
  50 struct timer_ops {
  51         /*
  52          * Get the current timer count
  53          *
  54          * @dev: The timer device
  55          * @count: pointer that returns the current 64-bit timer count
  56          * @return: 0 if OK, -ve on error
  57          */
  58         int (*get_count)(struct udevice *dev, u64 *count);
  59 };
  60
  61 /*
  62  * struct timer_dev_priv - information about a device used by the uclass
  63  *
  64  * @clock_rate: the timer input clock frequency
  65  */
  66 struct timer_dev_priv {
  67         unsigned long clock_rate;
  68 };
  69
  70 /**
  71  * timer_early_get_count() - Implement timer_get_count() before driver model
  72  *
  73  * If CONFIG_TIMER_EARLY is enabled, this function wil be called to return
  74  * the current timer value before the proper driver model timer is ready.
  75  * It should be implemented by one of the timer values. This is mostly useful
  76  * for tracing.
  77  */
  78 u64 timer_early_get_count(void);
  79
  80 /**
  81  * timer_early_get_rate() - Get the timer rate before driver model
  82  *
  83  * If CONFIG_TIMER_EARLY is enabled, this function wil be called to return
  84  * the current timer rate in Hz before the proper driver model timer is ready.
  85  * It should be implemented by one of the timer values. This is mostly useful
  86  * for tracing. This corresponds to the clock_rate value in struct
  87  * timer_dev_priv.
  88  */
  89 unsigned long timer_early_get_rate(void);
  90
  91 #endif  /* _TIMER_H_ */