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#define timer_get_ops(dev) ((struct timer_ops *)(dev)->driver->ops) 10 11/** 12 * dm_timer_init() - set up a timer for time keeping 13 * 14 * Sets up gd->timer if the device is not already bound, making sure it is 15 * probed and ready for use 16 * 17 * On success, inits gd->timer so that lib/timer can use it for future reference 18 * 19 * Returns: 0 on success, -EAGAIN if driver model is not ready yet, -ENODEV if 20 * no timer could be found, other error if the timer could not be bound or 21 * probed 22 */ 23int dm_timer_init(void); 24 25/** 26 * timer_timebase_fallback() - Helper for timers using timebase fallback 27 * @dev: A timer partially-probed timer device 28 * 29 * This is a helper function designed for timers which need to fall back on the 30 * cpu's timebase. This function is designed to be called during the driver's 31 * probe(). If there is a clocks or clock-frequency property in the timer's 32 * binding, then it will be used. Otherwise, the timebase of the current cpu 33 * will be used. This is initialized by the cpu driver, and usually gotten from 34 * ``/cpus/timebase-frequency`` or ``/cpus/cpu@X/timebase-frequency``. 35 * 36 * Return: 0 if OK, or negative error code on failure 37 */ 38int timer_timebase_fallback(struct udevice *dev); 39 40/** 41 * timer_conv_64() - convert 32-bit counter value to 64-bit 42 * @count: 32-bit counter value 43 * 44 * Return: 64-bit counter value 45 */ 46u64 timer_conv_64(u32 count); 47 48/** 49 * timer_get_count() - Get the current timer count 50 * @dev: The timer device 51 * @count: pointer that returns the current timer count 52 * 53 * Return: 0 if OK, -ve on error 54 */ 55int timer_get_count(struct udevice *dev, u64 *count); 56 57/** 58 * timer_get_rate() - Get the timer input clock frequency 59 * @dev: The timer device 60 * 61 * Return: the timer input clock frequency 62 */ 63unsigned long timer_get_rate(struct udevice *dev); 64 65/** 66 * struct timer_ops - Driver model timer operations 67 * 68 * The uclass interface is implemented by all timer devices which use 69 * driver model. 70 */ 71struct timer_ops { 72 /** 73 * @get_count: Get the current timer count 74 * 75 * @dev: The timer device 76 * 77 * This function may be called at any time after the driver is probed. 78 * All necessary initialization must be completed by the time probe() 79 * returns. The count returned by this functions should be monotonic. 80 * This function must succeed. 81 * 82 * Return: The current 64-bit timer count 83 */ 84 u64 (*get_count)(struct udevice *dev); 85}; 86 87/** 88 * struct timer_dev_priv - information about a device used by the uclass 89 * 90 * @clock_rate: the timer input clock frequency 91 */ 92struct timer_dev_priv { 93 unsigned long clock_rate; 94}; 95 96/** 97 * timer_early_get_count() - Implement timer_get_count() before driver model 98 * 99 * If ``CONFIG_TIMER_EARLY`` is enabled, this function wil be called to return 100 * the current timer value before the proper driver model timer is ready. 101 * It should be implemented by one of the timer values. This is mostly useful 102 * for tracing. 103 */ 104u64 timer_early_get_count(void); 105 106/** 107 * timer_early_get_rate() - Get the timer rate before driver model 108 * 109 * If ``CONFIG_TIMER_EARLY`` is enabled, this function wil be called to return 110 * the current timer rate in Hz before the proper driver model timer is ready. 111 * It should be implemented by one of the timer values. This is mostly useful 112 * for tracing. This corresponds to the clock_rate value in struct 113 * timer_dev_priv. 114 */ 115unsigned long timer_early_get_rate(void); 116 117#endif /* _TIMER_H_ */ 118