1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Copyright (C) 2015 Thomas Chou <thomas@wytron.com.tw> 4 */ 5 6 #ifndef _TIMER_H_ 7 #define _TIMER_H_ 8 9 /** 10 * dm_timer_init() - initialize a timer for time keeping. On success 11 * initializes gd->timer so that lib/timer can use it for future 12 * referrence. 13 * 14 * Return: 0 on success or error number 15 */ 16 int dm_timer_init(void); 17 18 /** 19 * timer_timebase_fallback() - Helper for timers using timebase fallback 20 * @dev: A timer partially-probed timer device 21 * 22 * This is a helper function designed for timers which need to fall back on the 23 * cpu's timebase. This function is designed to be called during the driver's 24 * probe(). If there is a clocks or clock-frequency property in the timer's 25 * binding, then it will be used. Otherwise, the timebase of the current cpu 26 * will be used. This is initialized by the cpu driver, and usually gotten from 27 * ``/cpus/timebase-frequency`` or ``/cpus/cpu@X/timebase-frequency``. 28 * 29 * Return: 0 if OK, or negative error code on failure 30 */ 31 int timer_timebase_fallback(struct udevice *dev); 32 33 /** 34 * timer_conv_64() - convert 32-bit counter value to 64-bit 35 * @count: 32-bit counter value 36 * 37 * Return: 64-bit counter value 38 */ 39 u64 timer_conv_64(u32 count); 40 41 /** 42 * timer_get_count() - Get the current timer count 43 * @dev: The timer device 44 * @count: pointer that returns the current timer count 45 * 46 * Return: 0 if OK, -ve on error 47 */ 48 int timer_get_count(struct udevice *dev, u64 *count); 49 50 /** 51 * timer_get_rate() - Get the timer input clock frequency 52 * @dev: The timer device 53 * 54 * Return: the timer input clock frequency 55 */ 56 unsigned long timer_get_rate(struct udevice *dev); 57 58 /** 59 * struct timer_ops - Driver model timer operations 60 * 61 * The uclass interface is implemented by all timer devices which use 62 * driver model. 63 */ 64 struct timer_ops { 65 /** 66 * @get_count: Get the current timer count 67 * 68 * @dev: The timer device 69 * 70 * This function may be called at any time after the driver is probed. 71 * All necessary initialization must be completed by the time probe() 72 * returns. The count returned by this functions should be monotonic. 73 * This function must succeed. 74 * 75 * Return: The current 64-bit timer count 76 */ 77 u64 (*get_count)(struct udevice *dev); 78 }; 79 80 /** 81 * struct timer_dev_priv - information about a device used by the uclass 82 * 83 * @clock_rate: the timer input clock frequency 84 */ 85 struct timer_dev_priv { 86 unsigned long clock_rate; 87 }; 88 89 /** 90 * timer_early_get_count() - Implement timer_get_count() before driver model 91 * 92 * If ``CONFIG_TIMER_EARLY`` is enabled, this function wil be called to return 93 * the current timer value before the proper driver model timer is ready. 94 * It should be implemented by one of the timer values. This is mostly useful 95 * for tracing. 96 */ 97 u64 timer_early_get_count(void); 98 99 /** 100 * timer_early_get_rate() - Get the timer rate before driver model 101 * 102 * If ``CONFIG_TIMER_EARLY`` is enabled, this function wil be called to return 103 * the current timer rate in Hz before the proper driver model timer is ready. 104 * It should be implemented by one of the timer values. This is mostly useful 105 * for tracing. This corresponds to the clock_rate value in struct 106 * timer_dev_priv. 107 */ 108 unsigned long timer_early_get_rate(void); 109 110 #endif /* _TIMER_H_ */ 111