xref: /openbmc/u-boot/include/timer.h (revision 8314bfe5)
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_ */
92