xref: /openbmc/u-boot/include/timer.h (revision e3963c09)
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_conv_64 - convert 32-bit counter value to 64-bit
20  *
21  * @count: 32-bit counter value
22  * @return: 64-bit counter value
23  */
24 u64 timer_conv_64(u32 count);
25 
26 /*
27  * Get the current timer count
28  *
29  * @dev: The timer device
30  * @count: pointer that returns the current timer count
31  * @return: 0 if OK, -ve on error
32  */
33 int timer_get_count(struct udevice *dev, u64 *count);
34 
35 /*
36  * Get the timer input clock frequency
37  *
38  * @dev: The timer device
39  * @return: the timer input clock frequency
40  */
41 unsigned long timer_get_rate(struct udevice *dev);
42 
43 /*
44  * struct timer_ops - Driver model timer operations
45  *
46  * The uclass interface is implemented by all timer devices which use
47  * driver model.
48  */
49 struct timer_ops {
50 	/*
51 	 * Get the current timer count
52 	 *
53 	 * @dev: The timer device
54 	 * @count: pointer that returns the current 64-bit timer count
55 	 * @return: 0 if OK, -ve on error
56 	 */
57 	int (*get_count)(struct udevice *dev, u64 *count);
58 };
59 
60 /*
61  * struct timer_dev_priv - information about a device used by the uclass
62  *
63  * @clock_rate: the timer input clock frequency
64  */
65 struct timer_dev_priv {
66 	unsigned long clock_rate;
67 };
68 
69 /**
70  * timer_early_get_count() - Implement timer_get_count() before driver model
71  *
72  * If CONFIG_TIMER_EARLY is enabled, this function wil be called to return
73  * the current timer value before the proper driver model timer is ready.
74  * It should be implemented by one of the timer values. This is mostly useful
75  * for tracing.
76  */
77 u64 timer_early_get_count(void);
78 
79 /**
80  * timer_early_get_rate() - Get the timer rate before driver model
81  *
82  * If CONFIG_TIMER_EARLY is enabled, this function wil be called to return
83  * the current timer rate in Hz before the proper driver model timer is ready.
84  * It should be implemented by one of the timer values. This is mostly useful
85  * for tracing. This corresponds to the clock_rate value in struct
86  * timer_dev_priv.
87  */
88 unsigned long timer_early_get_rate(void);
89 
90 #endif	/* _TIMER_H_ */
91