arch/powerpc/platforms/pasemi/cpufreq.c - maze/linux - Git at Google

 /*
  * Copyright (C) 2007 PA Semi, Inc
  *
  * Authors: Egor Martovetsky <egor@pasemi.com>
  *	    Olof Johansson <olof@lixom.net>
  *
  * Maintained by: Olof Johansson <olof@lixom.net>
  *
  * Based on arch/powerpc/platforms/cell/cbe_cpufreq.c:
  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
  *
  * 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
  *
  */

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

 #include <asm/hw_irq.h>
 #include <asm/io.h>
 #include <asm/prom.h>

 #define SDCASR_REG		0x0100
 #define SDCASR_REG_STRIDE	0x1000
 #define SDCPWR_CFGA0_REG	0x0100
 #define SDCPWR_PWST0_REG	0x0000
 #define SDCPWR_GIZTIME_REG	0x0440

 /* SDCPWR_GIZTIME_REG fields */
 #define SDCPWR_GIZTIME_GR	0x80000000
 #define SDCPWR_GIZTIME_LONGLOCK	0x000000ff

 /* Offset of ASR registers from SDC base */
 #define SDCASR_OFFSET		0x120000

 static void __iomem *sdcpwr_mapbase;
 static void __iomem *sdcasr_mapbase;

 static DEFINE_MUTEX(pas_switch_mutex);

 /* Current astate, is used when waking up from power savings on
  * one core, in case the other core has switched states during
  * the idle time.
  */
 static int current_astate;

 /* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
 static struct cpufreq_frequency_table pas_freqs[] = {
 	{0,	0},
 	{1,	0},
 	{2,	0},
 	{3,	0},
 	{4,	0},
 	{0,	CPUFREQ_TABLE_END},
 };

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

 /*
  * hardware specific functions
  */

 static int get_astate_freq(int astate)
 {
 	u32 ret;
 	ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10));

 	return ret & 0x3f;
 }

 static int get_cur_astate(int cpu)
 {
 	u32 ret;

 	ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG);
 	ret = (ret >> (cpu * 4)) & 0x7;

 	return ret;
 }

 static int get_gizmo_latency(void)
 {
 	u32 giztime, ret;

 	giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG);

 	/* just provide the upper bound */
 	if (giztime & SDCPWR_GIZTIME_GR)
 		ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000;
 	else
 		ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000;

 	return ret;
 }

 static void set_astate(int cpu, unsigned int astate)
 {
 	u64 flags;

 	/* Return if called before init has run */
 	if (unlikely(!sdcasr_mapbase))
 		return;

 	local_irq_save(flags);

 	out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate);

 	local_irq_restore(flags);
 }

 void restore_astate(int cpu)
 {
 	set_astate(cpu, current_astate);
 }

 /*
  * cpufreq functions
  */

 static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
 {
 	const u32 *max_freqp;
 	u32 max_freq;
 	int i, cur_astate;
 	struct resource res;
 	struct device_node *cpu, *dn;
 	int err = -ENODEV;

 	cpu = of_get_cpu_node(policy->cpu, NULL);

 	if (!cpu)
 		goto out;

 	dn = of_find_compatible_node(NULL, "sdc", "1682m-sdc");
 	if (!dn)
 		goto out;
 	err = of_address_to_resource(dn, 0, &res);
 	of_node_put(dn);
 	if (err)
 		goto out;
 	sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000);
 	if (!sdcasr_mapbase) {
 		err = -EINVAL;
 		goto out;
 	}

 	dn = of_find_compatible_node(NULL, "gizmo", "1682m-gizmo");
 	if (!dn) {
 		err = -ENODEV;
 		goto out_unmap_sdcasr;
 	}
 	err = of_address_to_resource(dn, 0, &res);
 	of_node_put(dn);
 	if (err)
 		goto out_unmap_sdcasr;
 	sdcpwr_mapbase = ioremap(res.start, 0x1000);
 	if (!sdcpwr_mapbase) {
 		err = -EINVAL;
 		goto out_unmap_sdcasr;
 	}

 	pr_debug("init cpufreq on CPU %d\n", policy->cpu);

 	max_freqp = of_get_property(cpu, "clock-frequency", NULL);
 	if (!max_freqp) {
 		err = -EINVAL;
 		goto out_unmap_sdcpwr;
 	}

 	/* we need the freq in kHz */
 	max_freq = *max_freqp / 1000;

 	pr_debug("max clock-frequency is at %u kHz\n", max_freq);
 	pr_debug("initializing frequency table\n");

 	/* initialize frequency table */
 	for (i=0; pas_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
 		pas_freqs[i].frequency = get_astate_freq(pas_freqs[i].index) * 100000;
 		pr_debug("%d: %d\n", i, pas_freqs[i].frequency);
 	}

 	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

 	policy->cpuinfo.transition_latency = get_gizmo_latency();

 	cur_astate = get_cur_astate(policy->cpu);
 	pr_debug("current astate is at %d\n",cur_astate);

 	policy->cur = pas_freqs[cur_astate].frequency;
 	policy->cpus = cpu_online_map;

 	cpufreq_frequency_table_get_attr(pas_freqs, policy->cpu);

 	/* this ensures that policy->cpuinfo_min and policy->cpuinfo_max
 	 * are set correctly
 	 */
 	return cpufreq_frequency_table_cpuinfo(policy, pas_freqs);

 out_unmap_sdcpwr:
 	iounmap(sdcpwr_mapbase);

 out_unmap_sdcasr:
 	iounmap(sdcasr_mapbase);
 out:
 	return err;
 }

 static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 {
 	if (sdcasr_mapbase)
 		iounmap(sdcasr_mapbase);
 	if (sdcpwr_mapbase)
 		iounmap(sdcpwr_mapbase);

 	cpufreq_frequency_table_put_attr(policy->cpu);
 	return 0;
 }

 static int pas_cpufreq_verify(struct cpufreq_policy *policy)
 {
 	return cpufreq_frequency_table_verify(policy, pas_freqs);
 }

 static int pas_cpufreq_target(struct cpufreq_policy *policy,
 			      unsigned int target_freq,
 			      unsigned int relation)
 {
 	struct cpufreq_freqs freqs;
 	int pas_astate_new;
 	int i;

 	cpufreq_frequency_table_target(policy,
 				       pas_freqs,
 				       target_freq,
 				       relation,
 				       &pas_astate_new);

 	freqs.old = policy->cur;
 	freqs.new = pas_freqs[pas_astate_new].frequency;
 	freqs.cpu = policy->cpu;

 	mutex_lock(&pas_switch_mutex);
 	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

 	pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n",
 		 policy->cpu,
 		 pas_freqs[pas_astate_new].frequency,
 		 pas_freqs[pas_astate_new].index);

 	current_astate = pas_astate_new;

 	for_each_online_cpu(i)
 		set_astate(i, pas_astate_new);

 	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 	mutex_unlock(&pas_switch_mutex);

 	return 0;
 }

 static struct cpufreq_driver pas_cpufreq_driver = {
 	.name		= "pas-cpufreq",
 	.owner		= THIS_MODULE,
 	.flags		= CPUFREQ_CONST_LOOPS,
 	.init		= pas_cpufreq_cpu_init,
 	.exit		= pas_cpufreq_cpu_exit,
 	.verify		= pas_cpufreq_verify,
 	.target		= pas_cpufreq_target,
 	.attr		= pas_cpu_freqs_attr,
 };

 /*
  * module init and destoy
  */

 static int __init pas_cpufreq_init(void)
 {
 	if (!machine_is_compatible("PA6T-1682M"))
 		return -ENODEV;

 	return cpufreq_register_driver(&pas_cpufreq_driver);
 }

 static void __exit pas_cpufreq_exit(void)
 {
 	cpufreq_unregister_driver(&pas_cpufreq_driver);
 }

 module_init(pas_cpufreq_init);
 module_exit(pas_cpufreq_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");
	/*
	* Copyright (C) 2007 PA Semi, Inc
	*
	* Authors: Egor Martovetsky <egor@pasemi.com>
	* Olof Johansson <olof@lixom.net>
	*
	* Maintained by: Olof Johansson <olof@lixom.net>
	*
	* Based on arch/powerpc/platforms/cell/cbe_cpufreq.c:
	* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
	*
	* 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
	*
	*/

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

	#include <asm/hw_irq.h>
	#include <asm/io.h>
	#include <asm/prom.h>

	#define SDCASR_REG 0x0100
	#define SDCASR_REG_STRIDE 0x1000
	#define SDCPWR_CFGA0_REG 0x0100
	#define SDCPWR_PWST0_REG 0x0000
	#define SDCPWR_GIZTIME_REG 0x0440

	/* SDCPWR_GIZTIME_REG fields */
	#define SDCPWR_GIZTIME_GR 0x80000000
	#define SDCPWR_GIZTIME_LONGLOCK 0x000000ff

	/* Offset of ASR registers from SDC base */
	#define SDCASR_OFFSET 0x120000

	static void __iomem *sdcpwr_mapbase;
	static void __iomem *sdcasr_mapbase;

	static DEFINE_MUTEX(pas_switch_mutex);

	/* Current astate, is used when waking up from power savings on
	* one core, in case the other core has switched states during
	* the idle time.
	*/
	static int current_astate;

	/* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
	static struct cpufreq_frequency_table pas_freqs[] = {
	{0, 0},
	{1, 0},
	{2, 0},
	{3, 0},
	{4, 0},
	{0, CPUFREQ_TABLE_END},
	};

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

	/*
	* hardware specific functions
	*/

	static int get_astate_freq(int astate)
	{
	u32 ret;
	ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10));

	return ret & 0x3f;
	}

	static int get_cur_astate(int cpu)
	{
	u32 ret;

	ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG);
	ret = (ret >> (cpu * 4)) & 0x7;

	return ret;
	}

	static int get_gizmo_latency(void)
	{
	u32 giztime, ret;

	giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG);

	/* just provide the upper bound */
	if (giztime & SDCPWR_GIZTIME_GR)
	ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000;
	else
	ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000;

	return ret;
	}

	static void set_astate(int cpu, unsigned int astate)
	{
	u64 flags;

	/* Return if called before init has run */
	if (unlikely(!sdcasr_mapbase))
	return;

	local_irq_save(flags);

	out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate);

	local_irq_restore(flags);
	}

	void restore_astate(int cpu)
	{
	set_astate(cpu, current_astate);
	}

	/*
	* cpufreq functions
	*/

	static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
	{
	const u32 *max_freqp;
	u32 max_freq;
	int i, cur_astate;
	struct resource res;
	struct device_node cpu, dn;
	int err = -ENODEV;

	cpu = of_get_cpu_node(policy->cpu, NULL);

	if (!cpu)
	goto out;

	dn = of_find_compatible_node(NULL, "sdc", "1682m-sdc");
	if (!dn)
	goto out;
	err = of_address_to_resource(dn, 0, &res);
	of_node_put(dn);
	if (err)
	goto out;
	sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000);
	if (!sdcasr_mapbase) {
	err = -EINVAL;
	goto out;
	}

	dn = of_find_compatible_node(NULL, "gizmo", "1682m-gizmo");
	if (!dn) {
	err = -ENODEV;
	goto out_unmap_sdcasr;
	}
	err = of_address_to_resource(dn, 0, &res);
	of_node_put(dn);
	if (err)
	goto out_unmap_sdcasr;
	sdcpwr_mapbase = ioremap(res.start, 0x1000);
	if (!sdcpwr_mapbase) {
	err = -EINVAL;
	goto out_unmap_sdcasr;
	}

	pr_debug("init cpufreq on CPU %d\n", policy->cpu);

	max_freqp = of_get_property(cpu, "clock-frequency", NULL);
	if (!max_freqp) {
	err = -EINVAL;
	goto out_unmap_sdcpwr;
	}

	/* we need the freq in kHz */
	max_freq = *max_freqp / 1000;

	pr_debug("max clock-frequency is at %u kHz\n", max_freq);
	pr_debug("initializing frequency table\n");

	/* initialize frequency table */
	for (i=0; pas_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
	pas_freqs[i].frequency = get_astate_freq(pas_freqs[i].index) * 100000;
	pr_debug("%d: %d\n", i, pas_freqs[i].frequency);
	}

	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

	policy->cpuinfo.transition_latency = get_gizmo_latency();

	cur_astate = get_cur_astate(policy->cpu);
	pr_debug("current astate is at %d\n",cur_astate);

	policy->cur = pas_freqs[cur_astate].frequency;
	policy->cpus = cpu_online_map;

	cpufreq_frequency_table_get_attr(pas_freqs, policy->cpu);

	/* this ensures that policy->cpuinfo_min and policy->cpuinfo_max
	* are set correctly
	*/
	return cpufreq_frequency_table_cpuinfo(policy, pas_freqs);

	out_unmap_sdcpwr:
	iounmap(sdcpwr_mapbase);

	out_unmap_sdcasr:
	iounmap(sdcasr_mapbase);
	out:
	return err;
	}

	static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)
	{
	if (sdcasr_mapbase)
	iounmap(sdcasr_mapbase);
	if (sdcpwr_mapbase)
	iounmap(sdcpwr_mapbase);

	cpufreq_frequency_table_put_attr(policy->cpu);
	return 0;
	}

	static int pas_cpufreq_verify(struct cpufreq_policy *policy)
	{
	return cpufreq_frequency_table_verify(policy, pas_freqs);
	}

	static int pas_cpufreq_target(struct cpufreq_policy *policy,
	unsigned int target_freq,
	unsigned int relation)
	{
	struct cpufreq_freqs freqs;
	int pas_astate_new;
	int i;

	cpufreq_frequency_table_target(policy,
	pas_freqs,
	target_freq,
	relation,
	&pas_astate_new);

	freqs.old = policy->cur;
	freqs.new = pas_freqs[pas_astate_new].frequency;
	freqs.cpu = policy->cpu;

	mutex_lock(&pas_switch_mutex);
	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n",
	policy->cpu,
	pas_freqs[pas_astate_new].frequency,
	pas_freqs[pas_astate_new].index);

	current_astate = pas_astate_new;

	for_each_online_cpu(i)
	set_astate(i, pas_astate_new);

	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	mutex_unlock(&pas_switch_mutex);

	return 0;
	}

	static struct cpufreq_driver pas_cpufreq_driver = {
	.name = "pas-cpufreq",
	.owner = THIS_MODULE,
	.flags = CPUFREQ_CONST_LOOPS,
	.init = pas_cpufreq_cpu_init,
	.exit = pas_cpufreq_cpu_exit,
	.verify = pas_cpufreq_verify,
	.target = pas_cpufreq_target,
	.attr = pas_cpu_freqs_attr,
	};

	/*
	* module init and destoy
	*/

	static int __init pas_cpufreq_init(void)
	{
	if (!machine_is_compatible("PA6T-1682M"))
	return -ENODEV;

	return cpufreq_register_driver(&pas_cpufreq_driver);
	}

	static void __exit pas_cpufreq_exit(void)
	{
	cpufreq_unregister_driver(&pas_cpufreq_driver);
	}

	module_init(pas_cpufreq_init);
	module_exit(pas_cpufreq_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");