summaryrefslogtreecommitdiff
path: root/arch/arm/plat-s3c/include/plat/cpu-freq.h
blob: 94eb06a2ea5cf28b5c32a71d18f7f77db0fa0a2f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
/* arch/arm/plat-s3c/include/plat/cpu-freq.h
 *
 * Copyright (c) 2006-2007 Simtec Electronics
 *	http://armlinux.simtec.co.uk/
 *	Ben Dooks <ben@simtec.co.uk>
 *
 * S3C CPU frequency scaling support - driver and board
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

#include <linux/cpufreq.h>

struct s3c_cpufreq_info;
struct s3c_cpufreq_board;
struct s3c_iotimings;

/**
 * struct s3c_freq - frequency information (mainly for core drivers)
 * @fclk: The FCLK frequency in Hz.
 * @armclk: The ARMCLK frequency in Hz.
 * @hclk_tns: HCLK cycle time in 10ths of nano-seconds.
 * @hclk: The HCLK frequency in Hz.
 * @pclk: The PCLK frequency in Hz.
 *
 * This contains the frequency information about the current configuration
 * mainly for the core drivers to ensure we do not end up passing about
 * a large number of parameters.
 *
 * The @hclk_tns field is a useful cache for the parts of the drivers that
 * need to calculate IO timings and suchlike.
 */
struct s3c_freq {
	unsigned long	fclk;
	unsigned long	armclk;
	unsigned long	hclk_tns;	/* in 10ths of ns */
	unsigned long	hclk;
	unsigned long	pclk;
};

/**
 * struct s3c_cpufreq_freqs - s3c cpufreq notification information.
 * @freqs: The cpufreq setting information.
 * @old: The old clock settings.
 * @new: The new clock settings.
 * @pll_changing: Set if the PLL is changing.
 *
 * Wrapper 'struct cpufreq_freqs' so that any drivers receiving the
 * notification can use this information that is not provided by just
 * having the core frequency alone.
 *
 * The pll_changing flag is used to indicate if the PLL itself is
 * being set during this change. This is important as the clocks
 * will temporarily be set to the XTAL clock during this time, so
 * drivers may want to close down their output during this time.
 *
 * Note, this is not being used by any current drivers and therefore
 * may be removed in the future.
 */
struct s3c_cpufreq_freqs {
	struct cpufreq_freqs	freqs;
	struct s3c_freq		old;
	struct s3c_freq		new;

	unsigned int		pll_changing:1;
};

#define to_s3c_cpufreq(_cf) container_of(_cf, struct s3c_cpufreq_freqs, freqs)

/**
 * struct s3c_clkdivs - clock divisor information
 * @p_divisor: Divisor from FCLK to PCLK.
 * @h_divisor: Divisor from FCLK to HCLK.
 * @arm_divisor: Divisor from FCLK to ARMCLK (not all CPUs).
 * @dvs: Non-zero if using DVS mode for ARMCLK.
 *
 * Divisor settings for the core clocks.
 */
struct s3c_clkdivs {
	int		p_divisor;
	int		h_divisor;
	int		arm_divisor;
	unsigned char	dvs;
};

#define PLLVAL(_m, _p, _s) (((_m) << 12) | ((_p) << 4) | (_s))

/**
 * struct s3c_pllval - PLL value entry.
 * @freq: The frequency for this entry in Hz.
 * @pll_reg: The PLL register setting for this PLL value.
 */
struct s3c_pllval {
	unsigned long		freq;
	unsigned long		pll_reg;
};

/**
 * struct s3c_cpufreq_board - per-board cpu frequency informatin
 * @refresh: The SDRAM refresh period in nanoseconds.
 * @auto_io: Set if the IO timing settings should be generated from the
 *	initialisation time hardware registers.
 * @need_io: Set if the board has external IO on any of the chipselect
 *	lines that will require the hardware timing registers to be
 *	updated on a clock change.
 * @max: The maxium frequency limits for the system. Any field that
 *	is left at zero will use the CPU's settings.
 *
 * This contains the board specific settings that affect how the CPU
 * drivers chose settings. These include the memory refresh and IO
 * timing information.
 *
 * Registration depends on the driver being used, the ARMCLK only
 * implementation does not currently need this but the older style
 * driver requires this to be available.
 */
struct s3c_cpufreq_board {
	unsigned int	refresh;
	unsigned int	auto_io:1;	/* automatically init io timings. */
	unsigned int	need_io:1;	/* set if needs io timing support. */

	/* any non-zero field in here is taken as an upper limit. */
	struct s3c_freq	max;	/* frequency limits */
};

/* Things depending on frequency scaling. */
#ifdef CONFIG_CPU_FREQ_S3C
#define __init_or_cpufreq
#else
#define __init_or_cpufreq __init
#endif

/* Board functions */

#ifdef CONFIG_CPU_FREQ_S3C
extern int s3c_cpufreq_setboard(struct s3c_cpufreq_board *board);
#else

static inline int s3c_cpufreq_setboard(struct s3c_cpufreq_board *board)
{
	return 0;
}
#endif  /* CONFIG_CPU_FREQ_S3C */