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Commit aeec2990 authored by Kevin Hilman's avatar Kevin Hilman Committed by Russell King
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[ARM] OMAP2: Implement CPUfreq frequency table based on PRCM table 

This patch adds a CPUfreq frequency-table implementation for OMAP2 by
walking the PRCM rate-table for available entries and adding them to a
CPUfreq table.

CPUfreq can then be used to manage switching between all the available
entries in the PRCM rate table.  Either use the CPUfreq sysfs
interface directly, (see Section 3 of Documentation/cpu-freq/user-guide.txt)
or use the cpufrequtils package:
http://www.kernel.org/pub/linux/utils/kernel/cpufreq/cpufrequtils.html



Signed-off-by: default avatarKevin Hilman <khilman@mvista.com>

Updated to try to use cpufreq_table if it exists.

linux-omap source commit is 77ce544fa48deb7a2003f454624e3ca10d37ab87.

Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarPaul Walmsley <paul@pwsan.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent ae8578c0

arch/arm/mach-omap2/clock24xx.c

+42 −0
Original line number Diff line number Diff line
@@ -574,6 +574,45 @@ static int omap2_select_table_rate(struct clk *clk, unsigned long rate) 
	return 0;

}



#ifdef CONFIG_CPU_FREQ

/*

 * Walk PRCM rate table and fillout cpufreq freq_table

 */

static struct cpufreq_frequency_table freq_table[ARRAY_SIZE(rate_table)];



void omap2_clk_init_cpufreq_table(struct cpufreq_frequency_table **table)

{

	struct prcm_config *prcm;

	int i = 0;



	for (prcm = rate_table; prcm->mpu_speed; prcm++) {

		if (!(prcm->flags & cpu_mask))

			continue;

		if (prcm->xtal_speed != sys_ck.rate)

			continue;



		/* don't put bypass rates in table */

		if (prcm->dpll_speed == prcm->xtal_speed)

			continue;



		freq_table[i].index = i;

		freq_table[i].frequency = prcm->mpu_speed / 1000;

		i++;

	}



	if (i == 0) {

		printk(KERN_WARNING "%s: failed to initialize frequency "

		       "table\n", __func__);

		return;

	}



	freq_table[i].index = i;

	freq_table[i].frequency = CPUFREQ_TABLE_END;



	*table = &freq_table[0];

}

#endif



static struct clk_functions omap2_clk_functions = {

	.clk_enable		= omap2_clk_enable,

	.clk_disable		= omap2_clk_disable,
@@ -581,6 +620,9 @@ static struct clk_functions omap2_clk_functions = { 
	.clk_set_rate		= omap2_clk_set_rate,

	.clk_set_parent		= omap2_clk_set_parent,

	.clk_disable_unused	= omap2_clk_disable_unused,

#ifdef	CONFIG_CPU_FREQ

	.clk_init_cpufreq_table	= omap2_clk_init_cpufreq_table,

#endif

};



static u32 omap2_get_apll_clkin(void)

arch/arm/plat-omap/cpu-omap.c

+53 −4
Original line number Diff line number Diff line
@@ -23,10 +23,13 @@ 
#include <linux/io.h>



#include <mach/hardware.h>

#include <mach/clock.h>

#include <asm/system.h>



#define VERY_HI_RATE	900000000



static struct cpufreq_frequency_table *freq_table;



#ifdef CONFIG_ARCH_OMAP1

#define MPU_CLK		"mpu"

#else
@@ -39,6 +42,9 @@ static struct clk *mpu_clk; 


int omap_verify_speed(struct cpufreq_policy *policy)

{

	if (freq_table)

		return cpufreq_frequency_table_verify(policy, freq_table);



	if (policy->cpu)

		return -EINVAL;
@@ -70,12 +76,26 @@ static int omap_target(struct cpufreq_policy *policy, 
	struct cpufreq_freqs freqs;

	int ret = 0;



	/* Ensure desired rate is within allowed range.  Some govenors

	 * (ondemand) will just pass target_freq=0 to get the minimum. */

	if (target_freq < policy->cpuinfo.min_freq)

		target_freq = policy->cpuinfo.min_freq;

	if (target_freq > policy->cpuinfo.max_freq)

		target_freq = policy->cpuinfo.max_freq;



	freqs.old = omap_getspeed(0);

	freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000;

	freqs.cpu = 0;



	if (freqs.old == freqs.new)

		return ret;



	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	ret = clk_set_rate(mpu_clk, target_freq * 1000);

#ifdef CONFIG_CPU_FREQ_DEBUG

	printk(KERN_DEBUG "cpufreq-omap: transition: %u --> %u\n",

	       freqs.old, freqs.new);

#endif

	ret = clk_set_rate(mpu_clk, freqs.new * 1000);

	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);



	return ret;
@@ -83,16 +103,31 @@ static int omap_target(struct cpufreq_policy *policy, 


static int __init omap_cpu_init(struct cpufreq_policy *policy)

{

	int result = 0;



	mpu_clk = clk_get(NULL, MPU_CLK);

	if (IS_ERR(mpu_clk))

		return PTR_ERR(mpu_clk);



	if (policy->cpu != 0)

		return -EINVAL;



	policy->cur = policy->min = policy->max = omap_getspeed(0);



	clk_init_cpufreq_table(&freq_table);

	if (freq_table) {

		result = cpufreq_frequency_table_cpuinfo(policy, freq_table);

		if (!result)

			cpufreq_frequency_table_get_attr(freq_table,

							policy->cpu);

	} else {

		policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000;

	policy->cpuinfo.max_freq = clk_round_rate(mpu_clk, VERY_HI_RATE) / 1000;

	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;

		policy->cpuinfo.max_freq = clk_round_rate(mpu_clk,

							VERY_HI_RATE) / 1000;

	}



	/* FIXME: what's the actual transition time? */

	policy->cpuinfo.transition_latency = 10 * 1000 * 1000;



	return 0;

}
@@ -103,6 +138,11 @@ static int omap_cpu_exit(struct cpufreq_policy *policy) 
	return 0;

}



static struct freq_attr *omap_cpufreq_attr[] = {

	&cpufreq_freq_attr_scaling_available_freqs,

	NULL,

};



static struct cpufreq_driver omap_driver = {

	.flags		= CPUFREQ_STICKY,

	.verify		= omap_verify_speed,
@@ -111,6 +151,7 @@ static struct cpufreq_driver omap_driver = { 
	.init		= omap_cpu_init,

	.exit		= omap_cpu_exit,

	.name		= "omap",

	.attr		= omap_cpufreq_attr,

};



static int __init omap_cpufreq_init(void)
@@ -119,3 +160,11 @@ static int __init omap_cpufreq_init(void) 
}



arch_initcall(omap_cpufreq_init);



/*

 * if ever we want to remove this, upon cleanup call:

 *

 * cpufreq_unregister_driver()

 * cpufreq_frequency_table_put_attr()

 */

arch/arm/plat-omap/include/mach/clock.h

+3 −0
Original line number Diff line number Diff line
@@ -121,6 +121,9 @@ extern void recalculate_root_clocks(void); 
extern void followparent_recalc(struct clk *clk);

extern int clk_get_usecount(struct clk *clk);

extern void clk_enable_init_clocks(void);

#ifdef CONFIG_CPU_FREQ

extern void clk_init_cpufreq_table(struct cpufreq_frequency_table **table);

#endif



extern const struct clkops clkops_null;