[CPUFREQ] AMD Elan SC520 cpufreq driver. (bf6fc9fd) · Commits · e / devices / android_kernel_sony_msm8998

arch/i386/kernel/cpu/cpufreq/Kconfig

+13 −1

Original line number	Diff line number	Diff line
		@@ -23,7 +23,7 @@ config X86_ACPI_CPUFREQ
		If in doubt, say N.

		config ELAN_CPUFREQ
		tristate "AMD Elan"
		tristate "AMD Elan SC400 and SC410"
		select CPU_FREQ_TABLE
		depends on X86_ELAN
		---help---
		@@ -38,6 +38,18 @@ config ELAN_CPUFREQ

		If in doubt, say N.

		config SC520_CPUFREQ
		tristate "AMD Elan SC520"
		select CPU_FREQ_TABLE
		depends on X86_ELAN
		---help---
		This adds the CPUFreq driver for AMD Elan SC520 processor.

		For details, take a look at <file:Documentation/cpu-freq/>.

		If in doubt, say N.


		config X86_POWERNOW_K6
		tristate "AMD Mobile K6-2/K6-3 PowerNow!"
		select CPU_FREQ_TABLE

arch/i386/kernel/cpu/cpufreq/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -3,6 +3,7 @@ obj-$(CONFIG_X86_POWERNOW_K7) += powernow-k7.o
		obj-$(CONFIG_X86_POWERNOW_K8) += powernow-k8.o
		obj-$(CONFIG_X86_LONGHAUL) += longhaul.o
		obj-$(CONFIG_ELAN_CPUFREQ) += elanfreq.o
		obj-$(CONFIG_SC520_CPUFREQ) += sc520_freq.o
		obj-$(CONFIG_X86_LONGRUN) += longrun.o
		obj-$(CONFIG_X86_GX_SUSPMOD) += gx-suspmod.o
		obj-$(CONFIG_X86_SPEEDSTEP_ICH) += speedstep-ich.o

arch/i386/kernel/cpu/cpufreq/sc520_freq.c

0 → 100644

+186 −0

Original line number	Diff line number	Diff line
		/*
		* sc520_freq.c: cpufreq driver for the AMD Elan sc520
		*
		* Copyright (C) 2005 Sean Young <sean@mess.org>
		*
		* 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.
		*
		* Based on elanfreq.c
		*
		* 2005-03-30: - initial revision
		*/

		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/init.h>

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

		#include <asm/msr.h>
		#include <asm/timex.h>
		#include <asm/io.h>

		#define MMCR_BASE 0xfffef000 /* The default base address */
		#define OFFS_CPUCTL 0x2 /* CPU Control Register */

		static __u8 __iomem *cpuctl;

		#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "sc520_freq", msg)

		static struct cpufreq_frequency_table sc520_freq_table[] = {
		{0x01, 100000},
		{0x02, 133000},
		{0, CPUFREQ_TABLE_END},
		};

		static unsigned int sc520_freq_get_cpu_frequency(unsigned int cpu)
		{
		u8 clockspeed_reg = *cpuctl;

		switch (clockspeed_reg & 0x03) {
		default:
		printk(KERN_ERR "sc520_freq: error: cpuctl register has unexpected value %02x\n", clockspeed_reg);
		case 0x01:
		return 100000;
		case 0x02:
		return 133000;
		}
		}

		static void sc520_freq_set_cpu_state (unsigned int state)
		{

		struct cpufreq_freqs freqs;
		u8 clockspeed_reg;

		freqs.old = sc520_freq_get_cpu_frequency(0);
		freqs.new = sc520_freq_table[state].frequency;
		freqs.cpu = 0; /* AMD Elan is UP */

		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

		dprintk("attempting to set frequency to %i kHz\n",
		sc520_freq_table[state].frequency);

		local_irq_disable();

		clockspeed_reg = *cpuctl & ~0x03;
		*cpuctl = clockspeed_reg \| sc520_freq_table[state].index;

		local_irq_enable();

		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
		};

		static int sc520_freq_verify (struct cpufreq_policy *policy)
		{
		return cpufreq_frequency_table_verify(policy, &sc520_freq_table[0]);
		}

		static int sc520_freq_target (struct cpufreq_policy *policy,
		unsigned int target_freq,
		unsigned int relation)
		{
		unsigned int newstate = 0;

		if (cpufreq_frequency_table_target(policy, sc520_freq_table, target_freq, relation, &newstate))
		return -EINVAL;

		sc520_freq_set_cpu_state(newstate);

		return 0;
		}


		/*
		* Module init and exit code
		*/

		static int sc520_freq_cpu_init(struct cpufreq_policy *policy)
		{
		struct cpuinfo_x86 *c = cpu_data;
		int result;

		/* capability check */
		if (c->x86_vendor != X86_VENDOR_AMD \|\|
		c->x86 != 4 \|\| c->x86_model != 9)
		return -ENODEV;

		/* cpuinfo and default policy values */
		policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
		policy->cpuinfo.transition_latency = 1000000; /* 1ms */
		policy->cur = sc520_freq_get_cpu_frequency(0);

		result = cpufreq_frequency_table_cpuinfo(policy, sc520_freq_table);
		if (result)
		return (result);

		cpufreq_frequency_table_get_attr(sc520_freq_table, policy->cpu);

		return 0;
		}


		static int sc520_freq_cpu_exit(struct cpufreq_policy *policy)
		{
		cpufreq_frequency_table_put_attr(policy->cpu);
		return 0;
		}


		static struct freq_attr* sc520_freq_attr[] = {
		&cpufreq_freq_attr_scaling_available_freqs,
		NULL,
		};


		static struct cpufreq_driver sc520_freq_driver = {
		.get = sc520_freq_get_cpu_frequency,
		.verify = sc520_freq_verify,
		.target = sc520_freq_target,
		.init = sc520_freq_cpu_init,
		.exit = sc520_freq_cpu_exit,
		.name = "sc520_freq",
		.owner = THIS_MODULE,
		.attr = sc520_freq_attr,
		};


		static int __init sc520_freq_init(void)
		{
		struct cpuinfo_x86 *c = cpu_data;

		/* Test if we have the right hardware */
		if(c->x86_vendor != X86_VENDOR_AMD \|\|
		c->x86 != 4 \|\| c->x86_model != 9) {
		dprintk("no Elan SC520 processor found!\n");
		return -ENODEV;
		}
		cpuctl = ioremap((unsigned long)(MMCR_BASE + OFFS_CPUCTL), 1);
		if(!cpuctl) {
		printk(KERN_ERR "sc520_freq: error: failed to remap memory\n");
		return -ENOMEM;
		}

		return cpufreq_register_driver(&sc520_freq_driver);
		}


		static void __exit sc520_freq_exit(void)
		{
		cpufreq_unregister_driver(&sc520_freq_driver);
		iounmap(cpuctl);
		}


		MODULE_LICENSE("GPL");
		MODULE_AUTHOR("Sean Young <sean@mess.org>");
		MODULE_DESCRIPTION("cpufreq driver for AMD's Elan sc520 CPU");

		module_init(sc520_freq_init);
		module_exit(sc520_freq_exit);