ux500: Add cpufreq support for u8500 (7c1a70e9) · Commits · e / devices / android_kernel_teracube_2e

arch/arm/Kconfig

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Original line number	Diff line number	Diff line
		@@ -797,6 +797,7 @@ config ARCH_U8500
		select GENERIC_CLOCKEVENTS
		select COMMON_CLKDEV
		select ARCH_REQUIRE_GPIOLIB
		select ARCH_HAS_CPUFREQ
		help
		Support for ST-Ericsson's Ux500 architecture

arch/arm/mach-ux500/Makefile

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		@@ -13,3 +13,4 @@ obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o
		obj-$(CONFIG_REGULATOR_AB8500) += board-mop500-regulators.o
		obj-$(CONFIG_U5500_MODEM_IRQ) += modem_irq.o
		obj-$(CONFIG_U5500_MBOX) += mbox.o
		obj-$(CONFIG_CPU_FREQ) += cpufreq.o

arch/arm/mach-ux500/cpu-db8500.c

+1 −0

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		@@ -179,6 +179,7 @@ void __init u8500_init_devices(void)
		db8500_add_rtc();
		db8500_add_gpios();

		platform_device_register_simple("cpufreq-u8500", -1, NULL, 0);
		platform_add_devices(platform_devs, ARRAY_SIZE(platform_devs));

		return ;

arch/arm/mach-ux500/cpufreq.c

0 → 100644

+211 −0

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		/*
		* CPU frequency scaling for u8500
		* Inspired by linux/arch/arm/mach-davinci/cpufreq.c
		*
		* Copyright (C) STMicroelectronics 2009
		* Copyright (C) ST-Ericsson SA 2010
		*
		* License Terms: GNU General Public License v2
		*
		* Author: Sundar Iyer <sundar.iyer@stericsson.com>
		* Author: Martin Persson <martin.persson@stericsson.com>
		* Author: Jonas Aaberg <jonas.aberg@stericsson.com>
		*
		*/

		#include <linux/platform_device.h>
		#include <linux/kernel.h>
		#include <linux/cpufreq.h>
		#include <linux/delay.h>

		#include <mach/hardware.h>
		#include <mach/prcmu.h>
		#include <mach/prcmu-defs.h>

		#define DRIVER_NAME "cpufreq-u8500"
		#define CPUFREQ_NAME "u8500"

		static struct device *dev;

		static struct cpufreq_frequency_table freq_table[] = {
		[0] = {
		.index = 0,
		.frequency = 200000,
		},
		[1] = {
		.index = 1,
		.frequency = 300000,
		},
		[2] = {
		.index = 2,
		.frequency = 600000,
		},
		[3] = {
		/* Used for CPU_OPP_MAX, if available */
		.index = 3,
		.frequency = CPUFREQ_TABLE_END,
		},
		[4] = {
		.index = 4,
		.frequency = CPUFREQ_TABLE_END,
		},
		};

		static enum prcmu_cpu_opp index2opp[] = {
		CPU_OPP_EXT_CLK,
		CPU_OPP_50,
		CPU_OPP_100,
		CPU_OPP_MAX
		};

		static int u8500_cpufreq_verify_speed(struct cpufreq_policy *policy)
		{
		return cpufreq_frequency_table_verify(policy, freq_table);
		}

		static int u8500_cpufreq_target(struct cpufreq_policy *policy,
		unsigned int target_freq,
		unsigned int relation)
		{
		struct cpufreq_freqs freqs;
		unsigned int index;
		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;

		ret = cpufreq_frequency_table_target(policy, freq_table,
		target_freq, relation, &index);
		if (ret < 0) {
		dev_err(dev, "Could not look up next frequency\n");
		return ret;
		}

		freqs.old = policy->cur;
		freqs.new = freq_table[index].frequency;
		freqs.cpu = policy->cpu;

		if (freqs.old == freqs.new) {
		dev_dbg(dev, "Current and target frequencies are equal\n");
		return 0;
		}

		dev_dbg(dev, "transition: %u --> %u\n", freqs.old, freqs.new);
		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

		ret = prcmu_set_cpu_opp(index2opp[index]);
		if (ret < 0) {
		dev_err(dev, "Failed to set OPP level\n");
		return ret;
		}

		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

		return ret;
		}

		static unsigned int u8500_cpufreq_getspeed(unsigned int cpu)
		{
		int i;

		for (i = 0; prcmu_get_cpu_opp() != index2opp[i]; i++)
		;
		return freq_table[i].frequency;
		}

		static int __cpuinit u8500_cpu_init(struct cpufreq_policy *policy)
		{
		int res;

		BUILD_BUG_ON(ARRAY_SIZE(index2opp) + 1 != ARRAY_SIZE(freq_table));

		if (cpu_is_u8500v2()) {
		freq_table[1].frequency = 400000;
		freq_table[2].frequency = 800000;
		if (prcmu_has_arm_maxopp())
		freq_table[3].frequency = 1000000;
		}

		/* get policy fields based on the table */
		res = cpufreq_frequency_table_cpuinfo(policy, freq_table);
		if (!res)
		cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
		else {
		dev_err(dev, "u8500-cpufreq : Failed to read policy table\n");
		return res;
		}

		policy->min = policy->cpuinfo.min_freq;
		policy->max = policy->cpuinfo.max_freq;
		policy->cur = u8500_cpufreq_getspeed(policy->cpu);
		policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

		/*
		* FIXME : Need to take time measurement across the target()
		* function with no/some/all drivers in the notification
		* list.
		*/
		policy->cpuinfo.transition_latency = 200 * 1000; /* in ns */

		/* policy sharing between dual CPUs */
		cpumask_copy(policy->cpus, &cpu_present_map);

		policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;

		return res;
		}

		static struct freq_attr *u8500_cpufreq_attr[] = {
		&cpufreq_freq_attr_scaling_available_freqs,
		NULL,
		};
		static int u8500_cpu_exit(struct cpufreq_policy *policy)
		{
		cpufreq_frequency_table_put_attr(policy->cpu);
		return 0;
		}

		static struct cpufreq_driver u8500_driver = {
		.owner = THIS_MODULE,
		.flags = CPUFREQ_STICKY,
		.verify = u8500_cpufreq_verify_speed,
		.target = u8500_cpufreq_target,
		.get = u8500_cpufreq_getspeed,
		.init = u8500_cpu_init,
		.exit = u8500_cpu_exit,
		.name = CPUFREQ_NAME,
		.attr = u8500_cpufreq_attr,
		};

		static int __init u8500_cpufreq_probe(struct platform_device *pdev)
		{
		dev = &pdev->dev;
		return cpufreq_register_driver(&u8500_driver);
		}

		static int __exit u8500_cpufreq_remove(struct platform_device *pdev)
		{
		return cpufreq_unregister_driver(&u8500_driver);
		}

		static struct platform_driver u8500_cpufreq_driver = {
		.driver = {
		.name = DRIVER_NAME,
		.owner = THIS_MODULE,
		},
		.remove = __exit_p(u8500_cpufreq_remove),
		};

		static int __init u8500_cpufreq_init(void)
		{
		return platform_driver_probe(&u8500_cpufreq_driver,
		&u8500_cpufreq_probe);
		}

		device_initcall(u8500_cpufreq_init);