1/* arch/arm/plat-samsung/include/plat/cpu-freq.h
2 *
3 * Copyright (c) 2006-2007 Simtec Electronics
4 *	http://armlinux.simtec.co.uk/
5 *	Ben Dooks <ben@simtec.co.uk>
6 *
7 * S3C CPU frequency scaling support - driver and board
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12*/
13
14#include <linux/cpufreq.h>
15
16struct s3c_cpufreq_info;
17struct s3c_cpufreq_board;
18struct s3c_iotimings;
19
20/**
21 * struct s3c_freq - frequency information (mainly for core drivers)
22 * @fclk: The FCLK frequency in Hz.
23 * @armclk: The ARMCLK frequency in Hz.
24 * @hclk_tns: HCLK cycle time in 10ths of nano-seconds.
25 * @hclk: The HCLK frequency in Hz.
26 * @pclk: The PCLK frequency in Hz.
27 *
28 * This contains the frequency information about the current configuration
29 * mainly for the core drivers to ensure we do not end up passing about
30 * a large number of parameters.
31 *
32 * The @hclk_tns field is a useful cache for the parts of the drivers that
33 * need to calculate IO timings and suchlike.
34 */
35struct s3c_freq {
36	unsigned long	fclk;
37	unsigned long	armclk;
38	unsigned long	hclk_tns;	/* in 10ths of ns */
39	unsigned long	hclk;
40	unsigned long	pclk;
41};
42
43/**
44 * struct s3c_cpufreq_freqs - s3c cpufreq notification information.
45 * @freqs: The cpufreq setting information.
46 * @old: The old clock settings.
47 * @new: The new clock settings.
48 * @pll_changing: Set if the PLL is changing.
49 *
50 * Wrapper 'struct cpufreq_freqs' so that any drivers receiving the
51 * notification can use this information that is not provided by just
52 * having the core frequency alone.
53 *
54 * The pll_changing flag is used to indicate if the PLL itself is
55 * being set during this change. This is important as the clocks
56 * will temporarily be set to the XTAL clock during this time, so
57 * drivers may want to close down their output during this time.
58 *
59 * Note, this is not being used by any current drivers and therefore
60 * may be removed in the future.
61 */
62struct s3c_cpufreq_freqs {
63	struct cpufreq_freqs	freqs;
64	struct s3c_freq		old;
65	struct s3c_freq		new;
66
67	unsigned int		pll_changing:1;
68};
69
70#define to_s3c_cpufreq(_cf) container_of(_cf, struct s3c_cpufreq_freqs, freqs)
71
72/**
73 * struct s3c_clkdivs - clock divisor information
74 * @p_divisor: Divisor from FCLK to PCLK.
75 * @h_divisor: Divisor from FCLK to HCLK.
76 * @arm_divisor: Divisor from FCLK to ARMCLK (not all CPUs).
77 * @dvs: Non-zero if using DVS mode for ARMCLK.
78 *
79 * Divisor settings for the core clocks.
80 */
81struct s3c_clkdivs {
82	int		p_divisor;
83	int		h_divisor;
84	int		arm_divisor;
85	unsigned char	dvs;
86};
87
88#define PLLVAL(_m, _p, _s) (((_m) << 12) | ((_p) << 4) | (_s))
89
90/**
91 * struct s3c_pllval - PLL value entry.
92 * @freq: The frequency for this entry in Hz.
93 * @pll_reg: The PLL register setting for this PLL value.
94 */
95struct s3c_pllval {
96	unsigned long		freq;
97	unsigned long		pll_reg;
98};
99
100/**
101 * struct s3c_cpufreq_board - per-board cpu frequency informatin
102 * @refresh: The SDRAM refresh period in nanoseconds.
103 * @auto_io: Set if the IO timing settings should be generated from the
104 *	initialisation time hardware registers.
105 * @need_io: Set if the board has external IO on any of the chipselect
106 *	lines that will require the hardware timing registers to be
107 *	updated on a clock change.
108 * @max: The maxium frequency limits for the system. Any field that
109 *	is left at zero will use the CPU's settings.
110 *
111 * This contains the board specific settings that affect how the CPU
112 * drivers chose settings. These include the memory refresh and IO
113 * timing information.
114 *
115 * Registration depends on the driver being used, the ARMCLK only
116 * implementation does not currently need this but the older style
117 * driver requires this to be available.
118 */
119struct s3c_cpufreq_board {
120	unsigned int	refresh;
121	unsigned int	auto_io:1;	/* automatically init io timings. */
122	unsigned int	need_io:1;	/* set if needs io timing support. */
123
124	/* any non-zero field in here is taken as an upper limit. */
125	struct s3c_freq	max;	/* frequency limits */
126};
127
128/* Things depending on frequency scaling. */
129#ifdef CONFIG_ARM_S3C_CPUFREQ
130#define __init_or_cpufreq
131#else
132#define __init_or_cpufreq __init
133#endif
134
135/* Board functions */
136
137#ifdef CONFIG_ARM_S3C_CPUFREQ
138extern int s3c_cpufreq_setboard(struct s3c_cpufreq_board *board);
139#else
140
141static inline int s3c_cpufreq_setboard(struct s3c_cpufreq_board *board)
142{
143	return 0;
144}
145#endif  /* CONFIG_ARM_S3C_CPUFREQ */
146