1 /*
2 * arch/metag/include/asm/clock.h
3 *
4 * Copyright (C) 2012 Imagination Technologies Ltd.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11 #ifndef _METAG_CLOCK_H_
12 #define _METAG_CLOCK_H_
13
14 #include <asm/mach/arch.h>
15
16 /**
17 * struct meta_clock_desc - Meta Core clock callbacks.
18 * @get_core_freq: Get the frequency of the Meta core. If this is NULL, the
19 * core frequency will be determined like this:
20 * Meta 1: based on loops_per_jiffy.
21 * Meta 2: (EXPAND_TIMER_DIV + 1) MHz.
22 * If a "core" clock is provided by the device tree, it
23 * will override this function.
24 */
25 struct meta_clock_desc {
26 unsigned long (*get_core_freq)(void);
27 };
28
29 extern struct meta_clock_desc _meta_clock;
30
31 /*
32 * Perform platform clock initialisation, reading clocks from device tree etc.
33 * Only accessible during boot.
34 */
35 void init_metag_clocks(void);
36
37 /*
38 * Set up the default clock, ensuring all callbacks are valid - only accessible
39 * during boot.
40 */
41 void setup_meta_clocks(struct meta_clock_desc *desc);
42
43 /**
44 * get_coreclock() - Get the frequency of the Meta core clock.
45 *
46 * Returns: The Meta core clock frequency in Hz.
47 */
get_coreclock(void)48 static inline unsigned long get_coreclock(void)
49 {
50 /*
51 * Use the current clock callback. If set correctly this will provide
52 * the most accurate frequency as it can be calculated directly from the
53 * PLL configuration. otherwise a default callback will have been set
54 * instead.
55 */
56 return _meta_clock.get_core_freq();
57 }
58
59 #endif /* _METAG_CLOCK_H_ */
60