arch/arm/mach-imx/cpufreq.c - kernel/msm-4.9 - Gitiles

 /*
  * cpu.c: clock scaling for the iMX
  *
  * Copyright (C) 2000 2001, The Delft University of Technology
  * Copyright (c) 2004 Sascha Hauer <sascha@saschahauer.de>
  * Copyright (C) 2006 Inky Lung <ilung@cwlinux.com>
  * Copyright (C) 2006 Pavel Pisa, PiKRON <ppisa@pikron.com>
  *
  * Based on SA1100 version written by:
  * - Johan Pouwelse (J.A.Pouwelse@its.tudelft.nl): initial version
  * - Erik Mouw (J.A.K.Mouw@its.tudelft.nl):
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *
  */

 /*#define DEBUG*/

 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/cpufreq.h>
 #include <asm/system.h>

 #include <asm/hardware.h>

 #include "generic.h"

 #ifndef __val2mfld
 #define __val2mfld(mask,val) (((mask)&~((mask)<<1))*(val)&(mask))
 #endif
 #ifndef __mfld2val
 #define __mfld2val(mask,val) (((val)&(mask))/((mask)&~((mask)<<1)))
 #endif

 #define CR_920T_CLOCK_MODE	0xC0000000
 #define CR_920T_FASTBUS_MODE	0x00000000
 #define CR_920T_ASYNC_MODE	0xC0000000

 static u32 mpctl0_at_boot;
 static u32 bclk_div_at_boot;

 static void imx_set_async_mode(void)
 {
 	adjust_cr(CR_920T_CLOCK_MODE, CR_920T_ASYNC_MODE);
 }

 static void imx_set_fastbus_mode(void)
 {
 	adjust_cr(CR_920T_CLOCK_MODE, CR_920T_FASTBUS_MODE);
 }

 static void imx_set_mpctl0(u32 mpctl0)
 {
 	unsigned long flags;

 	if (mpctl0 == 0) {
 		local_irq_save(flags);
 		CSCR &= ~CSCR_MPEN;
 		local_irq_restore(flags);
 		return;
 	}

 	local_irq_save(flags);
 	MPCTL0 = mpctl0;
 	CSCR |= CSCR_MPEN;
 	local_irq_restore(flags);
 }

 /**
  * imx_compute_mpctl - compute new PLL parameters
  * @new_mpctl:	pointer to location assigned by new PLL control register value
  * @cur_mpctl:	current PLL control register parameters
  * @f_ref:	reference source frequency Hz
  * @freq:	required frequency in Hz
  * @relation:	is one of %CPUFREQ_RELATION_L (supremum)
  *		and %CPUFREQ_RELATION_H (infimum)
  */
 long imx_compute_mpctl(u32 *new_mpctl, u32 cur_mpctl, u32 f_ref, unsigned long freq, int relation)
 {
         u32 mfi;
         u32 mfn;
         u32 mfd;
         u32 pd;
 	unsigned long long ll;
 	long l;
 	long quot;

 	/* Fdppl=2*Fref*(MFI+MFN/(MFD+1))/(PD+1) */
 	/*  PD=<0,15>, MFD=<1,1023>, MFI=<5,15> MFN=<0,1022> */

 	if (cur_mpctl) {
 		mfd = ((cur_mpctl >> 16) & 0x3ff) + 1;
 		pd =  ((cur_mpctl >> 26) & 0xf) + 1;
 	} else {
 		pd=2; mfd=313;
 	}

 	/* pd=2; mfd=313; mfi=8; mfn=183; */
 	/* (MFI+MFN/(MFD)) = Fdppl / (2*Fref) * (PD); */

 	quot = (f_ref + (1 << 9)) >> 10;
 	l = (freq * pd + quot) / (2 * quot);
 	mfi = l >> 10;
 	mfn = ((l & ((1 << 10) - 1)) * mfd + (1 << 9)) >> 10;

 	mfd -= 1;
 	pd -= 1;

 	*new_mpctl = ((mfi & 0xf) << 10) | (mfn & 0x3ff) | ((mfd & 0x3ff) << 16)
 		| ((pd & 0xf) << 26);

 	ll = 2 * (unsigned long long)f_ref * ( (mfi<<16) + (mfn<<16) / (mfd+1) );
 	quot = (pd+1) * (1<<16);
 	ll += quot / 2;
 	do_div(ll, quot);
 	freq = ll;

 	pr_debug(KERN_DEBUG "imx: new PLL parameters pd=%d mfd=%d mfi=%d mfn=%d, freq=%ld\n",
 		pd, mfd, mfi, mfn, freq);

 	return freq;
 }


 static int imx_verify_speed(struct cpufreq_policy *policy)
 {
 	if (policy->cpu != 0)
 		return -EINVAL;

 	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, policy->cpuinfo.max_freq);

 	return 0;
 }

 static unsigned int imx_get_speed(unsigned int cpu)
 {
 	unsigned int freq;
 	unsigned int cr;
 	unsigned int cscr;
 	unsigned int bclk_div;

 	if (cpu)
 		return 0;

 	cscr = CSCR;
 	bclk_div = __mfld2val(CSCR_BCLK_DIV, cscr) + 1;
 	cr = get_cr();

 	if((cr & CR_920T_CLOCK_MODE) == CR_920T_FASTBUS_MODE) {
 		freq = imx_get_system_clk();
 		freq = (freq + bclk_div/2) / bclk_div;
 	} else {
 		freq = imx_get_mcu_clk();
 		if (cscr & CSCR_MPU_PRESC)
 			freq /= 2;
 	}

 	freq = (freq + 500) / 1000;

 	return freq;
 }

 static int imx_set_target(struct cpufreq_policy *policy,
 			  unsigned int target_freq,
 			  unsigned int relation)
 {
 	struct cpufreq_freqs freqs;
 	u32 mpctl0 = 0;
 	u32 cscr;
 	unsigned long flags;
 	long freq;
 	long sysclk;
 	unsigned int bclk_div = bclk_div_at_boot;

 	/*
 	 * Some governors do not respects CPU and policy lower limits
 	 * which leads to bad things (division by zero etc), ensure
 	 * that such things do not happen.
 	 */
 	if(target_freq < policy->cpuinfo.min_freq)
 		target_freq = policy->cpuinfo.min_freq;

 	if(target_freq < policy->min)
 		target_freq = policy->min;

 	freq = target_freq * 1000;

 	pr_debug(KERN_DEBUG "imx: requested frequency %ld Hz, mpctl0 at boot 0x%08x\n",
 			freq, mpctl0_at_boot);

 	sysclk = imx_get_system_clk();

 	if (freq > sysclk / bclk_div_at_boot + 1000000) {
 		freq = imx_compute_mpctl(&mpctl0, mpctl0_at_boot, CLK32 * 512, freq, relation);
 		if (freq < 0) {
 			printk(KERN_WARNING "imx: target frequency %ld Hz cannot be set\n", freq);
 			return -EINVAL;
 		}
 	} else {
 		if(freq + 1000 < sysclk) {
 			if (relation == CPUFREQ_RELATION_L)
 				bclk_div = (sysclk - 1000) / freq;
 			else
 				bclk_div = (sysclk + freq + 1000) / freq;

 			if(bclk_div > 16)
 				bclk_div = 16;
 			if(bclk_div < bclk_div_at_boot)
 				bclk_div = bclk_div_at_boot;
 		}
 		freq = (sysclk + bclk_div / 2) / bclk_div;
 	}

 	freqs.old = imx_get_speed(0);
 	freqs.new = (freq + 500) / 1000;
 	freqs.cpu = 0;
 	freqs.flags = 0;

 	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

 	local_irq_save(flags);

 	imx_set_fastbus_mode();

 	imx_set_mpctl0(mpctl0);

 	cscr = CSCR;
 	cscr &= ~CSCR_BCLK_DIV;
 	cscr |= __val2mfld(CSCR_BCLK_DIV, bclk_div - 1);
 	CSCR = cscr;

 	if(mpctl0) {
 		CSCR |= CSCR_MPLL_RESTART;

 		/* Wait until MPLL is stabilized */
 		while( CSCR & CSCR_MPLL_RESTART );

 		imx_set_async_mode();
 	}

 	local_irq_restore(flags);

 	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

 	pr_debug(KERN_INFO "imx: set frequency %ld Hz, running from %s\n",
 			freq, mpctl0? "MPLL": "SPLL");

 	return 0;
 }

 static int __init imx_cpufreq_driver_init(struct cpufreq_policy *policy)
 {
 	printk(KERN_INFO "i.MX cpu freq change driver v1.0\n");

 	if (policy->cpu != 0)
 		return -EINVAL;

 	policy->cur = policy->min = policy->max = imx_get_speed(0);
 	policy->cpuinfo.min_freq = 8000;
 	policy->cpuinfo.max_freq = 200000;
 	 /* Manual states, that PLL stabilizes in two CLK32 periods */
 	policy->cpuinfo.transition_latency = 4 * 1000000000LL / CLK32;
 	return 0;
 }

 static struct cpufreq_driver imx_driver = {
 	.flags		= CPUFREQ_STICKY,
 	.verify		= imx_verify_speed,
 	.target		= imx_set_target,
 	.get		= imx_get_speed,
 	.init		= imx_cpufreq_driver_init,
 	.name		= "imx",
 };

 static int __init imx_cpufreq_init(void)
 {
 	bclk_div_at_boot = __mfld2val(CSCR_BCLK_DIV, CSCR) + 1;
 	mpctl0_at_boot = 0;

 	if((CSCR & CSCR_MPEN) &&
 	   ((get_cr() & CR_920T_CLOCK_MODE) != CR_920T_FASTBUS_MODE))
 		mpctl0_at_boot = MPCTL0;

 	return cpufreq_register_driver(&imx_driver);
 }

 arch_initcall(imx_cpufreq_init);
	/*
	* cpu.c: clock scaling for the iMX
	*
	* Copyright (C) 2000 2001, The Delft University of Technology
	* Copyright (c) 2004 Sascha Hauer <sascha@saschahauer.de>
	* Copyright (C) 2006 Inky Lung <ilung@cwlinux.com>
	* Copyright (C) 2006 Pavel Pisa, PiKRON <ppisa@pikron.com>
	*
	* Based on SA1100 version written by:
	* - Johan Pouwelse (J.A.Pouwelse@its.tudelft.nl): initial version
	* - Erik Mouw (J.A.K.Mouw@its.tudelft.nl):
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	*/

	/#define DEBUG/

	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/init.h>
	#include <linux/cpufreq.h>
	#include <asm/system.h>

	#include <asm/hardware.h>

	#include "generic.h"

	#ifndef __val2mfld
	#define __val2mfld(mask,val) (((mask)&~((mask)<<1))*(val)&(mask))
	#endif
	#ifndef __mfld2val
	#define __mfld2val(mask,val) (((val)&(mask))/((mask)&~((mask)<<1)))
	#endif

	#define CR_920T_CLOCK_MODE 0xC0000000
	#define CR_920T_FASTBUS_MODE 0x00000000
	#define CR_920T_ASYNC_MODE 0xC0000000

	static u32 mpctl0_at_boot;
	static u32 bclk_div_at_boot;

	static void imx_set_async_mode(void)
	{
	adjust_cr(CR_920T_CLOCK_MODE, CR_920T_ASYNC_MODE);
	}

	static void imx_set_fastbus_mode(void)
	{
	adjust_cr(CR_920T_CLOCK_MODE, CR_920T_FASTBUS_MODE);
	}

	static void imx_set_mpctl0(u32 mpctl0)
	{
	unsigned long flags;

	if (mpctl0 == 0) {
	local_irq_save(flags);
	CSCR &= ~CSCR_MPEN;
	local_irq_restore(flags);
	return;
	}

	local_irq_save(flags);
	MPCTL0 = mpctl0;
	CSCR \|= CSCR_MPEN;
	local_irq_restore(flags);
	}

	/**
	* imx_compute_mpctl - compute new PLL parameters
	* @new_mpctl: pointer to location assigned by new PLL control register value
	* @cur_mpctl: current PLL control register parameters
	* @f_ref: reference source frequency Hz
	* @freq: required frequency in Hz
	* @relation: is one of %CPUFREQ_RELATION_L (supremum)
	* and %CPUFREQ_RELATION_H (infimum)
	*/
	long imx_compute_mpctl(u32 *new_mpctl, u32 cur_mpctl, u32 f_ref, unsigned long freq, int relation)
	{
	u32 mfi;
	u32 mfn;
	u32 mfd;
	u32 pd;
	unsigned long long ll;
	long l;
	long quot;

	/* Fdppl=2Fref(MFI+MFN/(MFD+1))/(PD+1) */
	/* PD=<0,15>, MFD=<1,1023>, MFI=<5,15> MFN=<0,1022> */

	if (cur_mpctl) {
	mfd = ((cur_mpctl >> 16) & 0x3ff) + 1;
	pd = ((cur_mpctl >> 26) & 0xf) + 1;
	} else {
	pd=2; mfd=313;
	}

	/* pd=2; mfd=313; mfi=8; mfn=183; */
	/* (MFI+MFN/(MFD)) = Fdppl / (2Fref) (PD); */

	quot = (f_ref + (1 << 9)) >> 10;
	l = (freq * pd + quot) / (2 * quot);
	mfi = l >> 10;
	mfn = ((l & ((1 << 10) - 1)) * mfd + (1 << 9)) >> 10;

	mfd -= 1;
	pd -= 1;

	*new_mpctl = ((mfi & 0xf) << 10) \| (mfn & 0x3ff) \| ((mfd & 0x3ff) << 16)
	\| ((pd & 0xf) << 26);

	ll = 2 * (unsigned long long)f_ref * ( (mfi<<16) + (mfn<<16) / (mfd+1) );
	quot = (pd+1) * (1<<16);
	ll += quot / 2;
	do_div(ll, quot);
	freq = ll;

	pr_debug(KERN_DEBUG "imx: new PLL parameters pd=%d mfd=%d mfi=%d mfn=%d, freq=%ld\n",
	pd, mfd, mfi, mfn, freq);

	return freq;
	}


	static int imx_verify_speed(struct cpufreq_policy *policy)
	{
	if (policy->cpu != 0)
	return -EINVAL;

	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, policy->cpuinfo.max_freq);

	return 0;
	}

	static unsigned int imx_get_speed(unsigned int cpu)
	{
	unsigned int freq;
	unsigned int cr;
	unsigned int cscr;
	unsigned int bclk_div;

	if (cpu)
	return 0;

	cscr = CSCR;
	bclk_div = __mfld2val(CSCR_BCLK_DIV, cscr) + 1;
	cr = get_cr();

	if((cr & CR_920T_CLOCK_MODE) == CR_920T_FASTBUS_MODE) {
	freq = imx_get_system_clk();
	freq = (freq + bclk_div/2) / bclk_div;
	} else {
	freq = imx_get_mcu_clk();
	if (cscr & CSCR_MPU_PRESC)
	freq /= 2;
	}

	freq = (freq + 500) / 1000;

	return freq;
	}

	static int imx_set_target(struct cpufreq_policy *policy,
	unsigned int target_freq,
	unsigned int relation)
	{
	struct cpufreq_freqs freqs;
	u32 mpctl0 = 0;
	u32 cscr;
	unsigned long flags;
	long freq;
	long sysclk;
	unsigned int bclk_div = bclk_div_at_boot;

	/*
	* Some governors do not respects CPU and policy lower limits
	* which leads to bad things (division by zero etc), ensure
	* that such things do not happen.
	*/
	if(target_freq < policy->cpuinfo.min_freq)
	target_freq = policy->cpuinfo.min_freq;

	if(target_freq < policy->min)
	target_freq = policy->min;

	freq = target_freq * 1000;

	pr_debug(KERN_DEBUG "imx: requested frequency %ld Hz, mpctl0 at boot 0x%08x\n",
	freq, mpctl0_at_boot);

	sysclk = imx_get_system_clk();

	if (freq > sysclk / bclk_div_at_boot + 1000000) {
	freq = imx_compute_mpctl(&mpctl0, mpctl0_at_boot, CLK32 * 512, freq, relation);
	if (freq < 0) {
	printk(KERN_WARNING "imx: target frequency %ld Hz cannot be set\n", freq);
	return -EINVAL;
	}
	} else {
	if(freq + 1000 < sysclk) {
	if (relation == CPUFREQ_RELATION_L)
	bclk_div = (sysclk - 1000) / freq;
	else
	bclk_div = (sysclk + freq + 1000) / freq;

	if(bclk_div > 16)
	bclk_div = 16;
	if(bclk_div < bclk_div_at_boot)
	bclk_div = bclk_div_at_boot;
	}
	freq = (sysclk + bclk_div / 2) / bclk_div;
	}

	freqs.old = imx_get_speed(0);
	freqs.new = (freq + 500) / 1000;
	freqs.cpu = 0;
	freqs.flags = 0;

	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	local_irq_save(flags);

	imx_set_fastbus_mode();

	imx_set_mpctl0(mpctl0);

	cscr = CSCR;
	cscr &= ~CSCR_BCLK_DIV;
	cscr \|= __val2mfld(CSCR_BCLK_DIV, bclk_div - 1);
	CSCR = cscr;

	if(mpctl0) {
	CSCR \|= CSCR_MPLL_RESTART;

	/* Wait until MPLL is stabilized */
	while( CSCR & CSCR_MPLL_RESTART );

	imx_set_async_mode();
	}

	local_irq_restore(flags);

	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	pr_debug(KERN_INFO "imx: set frequency %ld Hz, running from %s\n",
	freq, mpctl0? "MPLL": "SPLL");

	return 0;
	}

	static int __init imx_cpufreq_driver_init(struct cpufreq_policy *policy)
	{
	printk(KERN_INFO "i.MX cpu freq change driver v1.0\n");

	if (policy->cpu != 0)
	return -EINVAL;

	policy->cur = policy->min = policy->max = imx_get_speed(0);
	policy->cpuinfo.min_freq = 8000;
	policy->cpuinfo.max_freq = 200000;
	/* Manual states, that PLL stabilizes in two CLK32 periods */
	policy->cpuinfo.transition_latency = 4 * 1000000000LL / CLK32;
	return 0;
	}

	static struct cpufreq_driver imx_driver = {
	.flags = CPUFREQ_STICKY,
	.verify = imx_verify_speed,
	.target = imx_set_target,
	.get = imx_get_speed,
	.init = imx_cpufreq_driver_init,
	.name = "imx",
	};

	static int __init imx_cpufreq_init(void)
	{
	bclk_div_at_boot = __mfld2val(CSCR_BCLK_DIV, CSCR) + 1;
	mpctl0_at_boot = 0;

	if((CSCR & CSCR_MPEN) &&
	((get_cr() & CR_920T_CLOCK_MODE) != CR_920T_FASTBUS_MODE))
	mpctl0_at_boot = MPCTL0;

	return cpufreq_register_driver(&imx_driver);
	}

	arch_initcall(imx_cpufreq_init);