142 lines
4.2 KiB
C
Executable file
142 lines
4.2 KiB
C
Executable file
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (c) 2006-2007 Simtec Electronics
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* http://armlinux.simtec.co.uk/
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* Ben Dooks <ben@simtec.co.uk>
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*
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* S3C CPU frequency scaling support - driver and board
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*/
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#include <linux/cpufreq.h>
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struct s3c_cpufreq_info;
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struct s3c_cpufreq_board;
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struct s3c_iotimings;
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/**
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* struct s3c_freq - frequency information (mainly for core drivers)
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* @fclk: The FCLK frequency in Hz.
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* @armclk: The ARMCLK frequency in Hz.
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* @hclk_tns: HCLK cycle time in 10ths of nano-seconds.
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* @hclk: The HCLK frequency in Hz.
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* @pclk: The PCLK frequency in Hz.
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*
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* This contains the frequency information about the current configuration
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* mainly for the core drivers to ensure we do not end up passing about
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* a large number of parameters.
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*
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* The @hclk_tns field is a useful cache for the parts of the drivers that
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* need to calculate IO timings and suchlike.
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*/
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struct s3c_freq {
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unsigned long fclk;
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unsigned long armclk;
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unsigned long hclk_tns; /* in 10ths of ns */
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unsigned long hclk;
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unsigned long pclk;
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};
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/**
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* struct s3c_cpufreq_freqs - s3c cpufreq notification information.
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* @freqs: The cpufreq setting information.
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* @old: The old clock settings.
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* @new: The new clock settings.
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* @pll_changing: Set if the PLL is changing.
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*
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* Wrapper 'struct cpufreq_freqs' so that any drivers receiving the
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* notification can use this information that is not provided by just
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* having the core frequency alone.
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*
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* The pll_changing flag is used to indicate if the PLL itself is
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* being set during this change. This is important as the clocks
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* will temporarily be set to the XTAL clock during this time, so
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* drivers may want to close down their output during this time.
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*
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* Note, this is not being used by any current drivers and therefore
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* may be removed in the future.
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*/
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struct s3c_cpufreq_freqs {
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struct cpufreq_freqs freqs;
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struct s3c_freq old;
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struct s3c_freq new;
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unsigned int pll_changing:1;
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};
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#define to_s3c_cpufreq(_cf) container_of(_cf, struct s3c_cpufreq_freqs, freqs)
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/**
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* struct s3c_clkdivs - clock divisor information
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* @p_divisor: Divisor from FCLK to PCLK.
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* @h_divisor: Divisor from FCLK to HCLK.
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* @arm_divisor: Divisor from FCLK to ARMCLK (not all CPUs).
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* @dvs: Non-zero if using DVS mode for ARMCLK.
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*
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* Divisor settings for the core clocks.
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*/
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struct s3c_clkdivs {
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int p_divisor;
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int h_divisor;
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int arm_divisor;
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unsigned char dvs;
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};
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#define PLLVAL(_m, _p, _s) (((_m) << 12) | ((_p) << 4) | (_s))
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/**
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* struct s3c_pllval - PLL value entry.
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* @freq: The frequency for this entry in Hz.
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* @pll_reg: The PLL register setting for this PLL value.
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*/
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struct s3c_pllval {
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unsigned long freq;
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unsigned long pll_reg;
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};
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/**
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* struct s3c_cpufreq_board - per-board cpu frequency informatin
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* @refresh: The SDRAM refresh period in nanoseconds.
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* @auto_io: Set if the IO timing settings should be generated from the
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* initialisation time hardware registers.
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* @need_io: Set if the board has external IO on any of the chipselect
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* lines that will require the hardware timing registers to be
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* updated on a clock change.
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* @max: The maxium frequency limits for the system. Any field that
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* is left at zero will use the CPU's settings.
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*
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* This contains the board specific settings that affect how the CPU
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* drivers chose settings. These include the memory refresh and IO
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* timing information.
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*
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* Registration depends on the driver being used, the ARMCLK only
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* implementation does not currently need this but the older style
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* driver requires this to be available.
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*/
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struct s3c_cpufreq_board {
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unsigned int refresh;
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unsigned int auto_io:1; /* automatically init io timings. */
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unsigned int need_io:1; /* set if needs io timing support. */
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/* any non-zero field in here is taken as an upper limit. */
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struct s3c_freq max; /* frequency limits */
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};
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/* Things depending on frequency scaling. */
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#ifdef CONFIG_ARM_S3C_CPUFREQ
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#define __init_or_cpufreq
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#else
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#define __init_or_cpufreq __init
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#endif
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/* Board functions */
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#ifdef CONFIG_ARM_S3C_CPUFREQ
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extern int s3c_cpufreq_setboard(struct s3c_cpufreq_board *board);
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#else
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static inline int s3c_cpufreq_setboard(struct s3c_cpufreq_board *board)
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{
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return 0;
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}
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#endif /* CONFIG_ARM_S3C_CPUFREQ */
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