[ARM] tegra: Add cpufreq support (7056d423) · Commits · 戴 / test

arch/arm/Kconfig

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Original line number	Original line	Diff line number	Diff line
	@@ -573,6 +573,7 @@ config ARCH_TEGRA
	select HAVE_CLK		select HAVE_CLK
	select COMMON_CLKDEV		select COMMON_CLKDEV
	select ARCH_HAS_BARRIERS if CACHE_L2X0		select ARCH_HAS_BARRIERS if CACHE_L2X0
			select ARCH_HAS_CPUFREQ
	help		help
	This enables support for NVIDIA Tegra based systems (Tegra APX,		This enables support for NVIDIA Tegra based systems (Tegra APX,
	Tegra 6xx and Tegra 2 series).		Tegra 6xx and Tegra 2 series).

arch/arm/mach-tegra/Makefile

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Original line number	Original line	Diff line number	Diff line
	@@ -12,6 +12,7 @@ obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra2_dvfs.o
	obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += pinmux-t2-tables.o		obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += pinmux-t2-tables.o
	obj-$(CONFIG_SMP) += platsmp.o localtimer.o headsmp.o		obj-$(CONFIG_SMP) += platsmp.o localtimer.o headsmp.o
	obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o		obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
			obj-$(CONFIG_CPU_FREQ) += cpu-tegra.o

	obj-${CONFIG_MACH_HARMONY} += board-harmony.o		obj-${CONFIG_MACH_HARMONY} += board-harmony.o
	obj-${CONFIG_MACH_HARMONY} += board-harmony-pinmux.o		obj-${CONFIG_MACH_HARMONY} += board-harmony-pinmux.o

arch/arm/mach-tegra/cpu-tegra.c

0 → 100644

+185 −0

Original line number	Original line	Diff line number	Diff line
			/*
			* arch/arm/mach-tegra/cpu-tegra.c
			*
			* Copyright (C) 2010 Google, Inc.
			*
			* Author:
			* Colin Cross <ccross@google.com>
			* Based on arch/arm/plat-omap/cpu-omap.c, (C) 2005 Nokia Corporation
			*
			* This software is licensed under the terms of the GNU General Public
			* License version 2, as published by the Free Software Foundation, and
			* may be copied, distributed, and modified under those terms.
			*
			* 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.
			*
			*/

			#include <linux/kernel.h>
			#include <linux/module.h>
			#include <linux/types.h>
			#include <linux/sched.h>
			#include <linux/cpufreq.h>
			#include <linux/delay.h>
			#include <linux/init.h>
			#include <linux/err.h>
			#include <linux/clk.h>
			#include <linux/io.h>

			#include <asm/system.h>

			#include <mach/hardware.h>
			#include <mach/clk.h>

			/* Frequency table index must be sequential starting at 0 */
			static struct cpufreq_frequency_table freq_table[] = {
			{ 0, 312000 },
			{ 1, 456000 },
			{ 2, 608000 },
			{ 3, 760000 },
			{ 4, 816000 },
			{ 5, 912000 },
			{ 6, 1000000 },
			{ 7, CPUFREQ_TABLE_END },
			};

			#define NUM_CPUS 2

			static struct clk *cpu_clk;

			static unsigned long target_cpu_speed[NUM_CPUS];

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

			unsigned int tegra_getspeed(unsigned int cpu)
			{
			unsigned long rate;

			if (cpu >= NUM_CPUS)
			return 0;

			rate = clk_get_rate(cpu_clk) / 1000;
			return rate;
			}

			static int tegra_update_cpu_speed(void)
			{
			int i;
			unsigned long rate = 0;
			int ret = 0;
			struct cpufreq_freqs freqs;

			for_each_online_cpu(i)
			rate = max(rate, target_cpu_speed[i]);

			freqs.old = tegra_getspeed(0);
			freqs.new = rate;

			if (freqs.old == freqs.new)
			return ret;

			for_each_online_cpu(freqs.cpu)
			cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

			#ifdef CONFIG_CPU_FREQ_DEBUG
			printk(KERN_DEBUG "cpufreq-tegra: transition: %u --> %u\n",
			freqs.old, freqs.new);
			#endif

			ret = clk_set_rate_cansleep(cpu_clk, freqs.new * 1000);
			if (ret) {
			pr_err("cpu-tegra: Failed to set cpu frequency to %d kHz\n",
			freqs.new);
			return ret;
			}

			for_each_online_cpu(freqs.cpu)
			cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

			return 0;
			}

			static int tegra_target(struct cpufreq_policy *policy,
			unsigned int target_freq,
			unsigned int relation)
			{
			int idx;
			unsigned int freq;

			cpufreq_frequency_table_target(policy, freq_table, target_freq,
			relation, &idx);

			freq = freq_table[idx].frequency;

			target_cpu_speed[policy->cpu] = freq;

			return tegra_update_cpu_speed();
			}

			static int tegra_cpu_init(struct cpufreq_policy *policy)
			{
			if (policy->cpu >= NUM_CPUS)
			return -EINVAL;

			cpu_clk = clk_get_sys(NULL, "cpu");
			if (IS_ERR(cpu_clk))
			return PTR_ERR(cpu_clk);

			cpufreq_frequency_table_cpuinfo(policy, freq_table);
			cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
			policy->cur = tegra_getspeed(policy->cpu);
			target_cpu_speed[policy->cpu] = policy->cur;

			/* FIXME: what's the actual transition time? */
			policy->cpuinfo.transition_latency = 300 * 1000;

			policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
			cpumask_copy(policy->related_cpus, cpu_possible_mask);

			return 0;
			}

			static int tegra_cpu_exit(struct cpufreq_policy *policy)
			{
			cpufreq_frequency_table_cpuinfo(policy, freq_table);
			clk_put(cpu_clk);
			return 0;
			}

			static struct freq_attr *tegra_cpufreq_attr[] = {
			&cpufreq_freq_attr_scaling_available_freqs,
			NULL,
			};

			static struct cpufreq_driver tegra_cpufreq_driver = {
			.verify = tegra_verify_speed,
			.target = tegra_target,
			.get = tegra_getspeed,
			.init = tegra_cpu_init,
			.exit = tegra_cpu_exit,
			.name = "tegra",
			.attr = tegra_cpufreq_attr,
			};

			static int __init tegra_cpufreq_init(void)
			{
			return cpufreq_register_driver(&tegra_cpufreq_driver);
			}

			static void __exit tegra_cpufreq_exit(void)
			{
			cpufreq_unregister_driver(&tegra_cpufreq_driver);
			}


			MODULE_AUTHOR("Colin Cross <ccross@android.com>");
			MODULE_DESCRIPTION("cpufreq driver for Nvidia Tegra2");
			MODULE_LICENSE("GPL");
			module_init(tegra_cpufreq_init);
			module_exit(tegra_cpufreq_exit);

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