[deliverable/linux.git] / drivers / cpufreq / pasemi-cpufreq.c

/*
 * 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 <linux/module.h>
#include <linux/of_address.h>

#include <asm/hw_irq.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/time.h>
#include <asm/smp.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;

/* 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},
};

/*
 * 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)
{
	unsigned long 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);
}

int check_astate(void)
{
	return get_cur_astate(hard_smp_processor_id());
}

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, NULL, "1682m-sdc");
	if (!dn)
		dn = of_find_compatible_node(NULL, NULL,
					     "pasemi,pwrficient-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, NULL, "1682m-gizmo");
	if (!dn)
		dn = of_find_compatible_node(NULL, NULL,
					     "pasemi,pwrficient-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].driver_data) * 100000;
		pr_debug("%d: %d\n", i, pas_freqs[i].frequency);
	}

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

	policy->cur = pas_freqs[cur_astate].frequency;
	ppc_proc_freq = policy->cur * 1000ul;

	return cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency());

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)
{
	/*
	 * We don't support CPU hotplug. Don't unmap after the system
	 * has already made it to a running state.
	 */
	if (system_state != SYSTEM_BOOTING)
		return 0;

	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_target(struct cpufreq_policy *policy,
			      unsigned int pas_astate_new)
{
	int i;

	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].driver_data);

	current_astate = pas_astate_new;

	for_each_online_cpu(i)
		set_astate(i, pas_astate_new);

	ppc_proc_freq = pas_freqs[pas_astate_new].frequency * 1000ul;
	return 0;
}

static struct cpufreq_driver pas_cpufreq_driver = {
	.name		= "pas-cpufreq",
	.flags		= CPUFREQ_CONST_LOOPS,
	.init		= pas_cpufreq_cpu_init,
	.exit		= pas_cpufreq_cpu_exit,
	.verify		= cpufreq_generic_frequency_table_verify,
	.target_index	= pas_cpufreq_target,
	.attr		= cpufreq_generic_attr,
};

/*
 * module init and destoy
 */

static int __init pas_cpufreq_init(void)
{
	if (!of_machine_is_compatible("PA6T-1682M") &&
	    !of_machine_is_compatible("pasemi,pwrficient"))
		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>");
Commit	Line	Data
2e0c3370 OJ	1	/*
	2	* Copyright (C) 2007 PA Semi, Inc
	3	*
	4	* Authors: Egor Martovetsky <egor@pasemi.com>
	5	* Olof Johansson <olof@lixom.net>
	6	*
	7	* Maintained by: Olof Johansson <olof@lixom.net>
	8	*
	9	* Based on arch/powerpc/platforms/cell/cbe_cpufreq.c:
	10	* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License as published by
	14	* the Free Software Foundation; either version 2, or (at your option)
	15	* any later version.
	16	*
	17	* This program is distributed in the hope that it will be useful,
	18	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	20	* GNU General Public License for more details.
	21	*
	22	* You should have received a copy of the GNU General Public License
	23	* along with this program; if not, write to the Free Software
	24	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	25	*
	26	*/
	27
	28	#include <linux/cpufreq.h>
	29	#include <linux/timer.h>
7dfe293c	30	#include <linux/module.h>
5af50730	31	#include <linux/of_address.h>
2e0c3370 OJ	32
	33	#include <asm/hw_irq.h>
	34	#include <asm/io.h>
	35	#include <asm/prom.h>
2abb7019	36	#include <asm/time.h>
8b32bc03	37	#include <asm/smp.h>
2e0c3370 OJ	38
	39	#define SDCASR_REG 0x0100
	40	#define SDCASR_REG_STRIDE 0x1000
	41	#define SDCPWR_CFGA0_REG 0x0100
	42	#define SDCPWR_PWST0_REG 0x0000
	43	#define SDCPWR_GIZTIME_REG 0x0440
	44
	45	/* SDCPWR_GIZTIME_REG fields */
	46	#define SDCPWR_GIZTIME_GR 0x80000000
	47	#define SDCPWR_GIZTIME_LONGLOCK 0x000000ff
	48
	49	/* Offset of ASR registers from SDC base */
	50	#define SDCASR_OFFSET 0x120000
	51
	52	static void __iomem *sdcpwr_mapbase;
	53	static void __iomem *sdcasr_mapbase;
	54
2e0c3370 OJ	55	/* Current astate, is used when waking up from power savings on
	56	* one core, in case the other core has switched states during
	57	* the idle time.
	58	*/
	59	static int current_astate;
	60
	61	/* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
	62	static struct cpufreq_frequency_table pas_freqs[] = {
	63	{0, 0},
	64	{1, 0},
	65	{2, 0},
	66	{3, 0},
	67	{4, 0},
	68	{0, CPUFREQ_TABLE_END},
	69	};
	70
2e0c3370 OJ	71	/*
	72	* hardware specific functions
	73	*/
	74
	75	static int get_astate_freq(int astate)
	76	{
	77	u32 ret;
	78	ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10));
	79
	80	return ret & 0x3f;
	81	}
	82
	83	static int get_cur_astate(int cpu)
	84	{
	85	u32 ret;
	86
	87	ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG);
	88	ret = (ret >> (cpu * 4)) & 0x7;
	89
	90	return ret;
	91	}
	92
	93	static int get_gizmo_latency(void)
	94	{
	95	u32 giztime, ret;
	96
	97	giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG);
	98
	99	/* just provide the upper bound */
	100	if (giztime & SDCPWR_GIZTIME_GR)
	101	ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000;
	102	else
	103	ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000;
	104
	105	return ret;
	106	}
	107
	108	static void set_astate(int cpu, unsigned int astate)
	109	{
ac3f6454	110	unsigned long flags;
2e0c3370 OJ	111
	112	/* Return if called before init has run */
	113	if (unlikely(!sdcasr_mapbase))
	114	return;
	115
	116	local_irq_save(flags);
	117
	118	out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate);
	119
	120	local_irq_restore(flags);
	121	}
	122
8b32bc03 OJ	123	int check_astate(void)
	124	{
	125	return get_cur_astate(hard_smp_processor_id());
	126	}
	127
2e0c3370 OJ	128	void restore_astate(int cpu)
	129	{
	130	set_astate(cpu, current_astate);
	131	}
	132
	133	/*
	134	* cpufreq functions
	135	*/
	136
	137	static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
	138	{
12d371a6 SR	139	const u32 *max_freqp;
12d371a6 SR	140	u32 max_freq;
2e0c3370 OJ	141	int i, cur_astate;
	142	struct resource res;
	143	struct device_node cpu, dn;
	144	int err = -ENODEV;
	145
	146	cpu = of_get_cpu_node(policy->cpu, NULL);
	147
	148	if (!cpu)
	149	goto out;
	150
0d08a847 OJ	151	dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
	152	if (!dn)
	153	dn = of_find_compatible_node(NULL, NULL,
	154	"pasemi,pwrficient-sdc");
2e0c3370 OJ	155	if (!dn)
	156	goto out;
	157	err = of_address_to_resource(dn, 0, &res);
	158	of_node_put(dn);
	159	if (err)
	160	goto out;
	161	sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000);
	162	if (!sdcasr_mapbase) {
	163	err = -EINVAL;
	164	goto out;
	165	}
	166
0d08a847 OJ	167	dn = of_find_compatible_node(NULL, NULL, "1682m-gizmo");
	168	if (!dn)
	169	dn = of_find_compatible_node(NULL, NULL,
	170	"pasemi,pwrficient-gizmo");
2e0c3370 OJ	171	if (!dn) {
	172	err = -ENODEV;
	173	goto out_unmap_sdcasr;
	174	}
	175	err = of_address_to_resource(dn, 0, &res);
	176	of_node_put(dn);
	177	if (err)
	178	goto out_unmap_sdcasr;
	179	sdcpwr_mapbase = ioremap(res.start, 0x1000);
	180	if (!sdcpwr_mapbase) {
	181	err = -EINVAL;
	182	goto out_unmap_sdcasr;
	183	}
	184
	185	pr_debug("init cpufreq on CPU %d\n", policy->cpu);
	186
12d371a6 SR	187	max_freqp = of_get_property(cpu, "clock-frequency", NULL);
12d371a6 SR	188	if (!max_freqp) {
2e0c3370 OJ	189	err = -EINVAL;
	190	goto out_unmap_sdcpwr;
	191	}
	192
	193	/* we need the freq in kHz */
12d371a6	194	max_freq = *max_freqp / 1000;
2e0c3370	195
12d371a6	196	pr_debug("max clock-frequency is at %u kHz\n", max_freq);
2e0c3370 OJ	197	pr_debug("initializing frequency table\n");
	198
	199	/* initialize frequency table */
	200	for (i=0; pas_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
50701588 VK	201	pas_freqs[i].frequency =
50701588 VK	202	get_astate_freq(pas_freqs[i].driver_data) * 100000;
2e0c3370 OJ	203	pr_debug("%d: %d\n", i, pas_freqs[i].frequency);
	204	}
	205
2e0c3370 OJ	206	cur_astate = get_cur_astate(policy->cpu);
	207	pr_debug("current astate is at %d\n",cur_astate);
	208
	209	policy->cur = pas_freqs[cur_astate].frequency;
2abb7019 OJ	210	ppc_proc_freq = policy->cur * 1000ul;
2abb7019 OJ	211
e315bb73	212	return cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency());
2e0c3370 OJ	213
	214	out_unmap_sdcpwr:
	215	iounmap(sdcpwr_mapbase);
	216
	217	out_unmap_sdcasr:
	218	iounmap(sdcasr_mapbase);
	219	out:
	220	return err;
	221	}
	222
	223	static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)
	224	{
72640d88 SR	225	/*
	226	* We don't support CPU hotplug. Don't unmap after the system
	227	* has already made it to a running state.
	228	*/
	229	if (system_state != SYSTEM_BOOTING)
	230	return 0;
	231
2e0c3370 OJ	232	if (sdcasr_mapbase)
	233	iounmap(sdcasr_mapbase);
	234	if (sdcpwr_mapbase)
	235	iounmap(sdcpwr_mapbase);
	236
	237	cpufreq_frequency_table_put_attr(policy->cpu);
	238	return 0;
	239	}
	240
2e0c3370	241	static int pas_cpufreq_target(struct cpufreq_policy *policy,
9c0ebcf7	242	unsigned int pas_astate_new)
2e0c3370	243	{
2e0c3370 OJ	244	int i;
2e0c3370 OJ	245
2e0c3370 OJ	246	pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n",
	247	policy->cpu,
	248	pas_freqs[pas_astate_new].frequency,
50701588	249	pas_freqs[pas_astate_new].driver_data);
2e0c3370 OJ	250
	251	current_astate = pas_astate_new;
	252
	253	for_each_online_cpu(i)
	254	set_astate(i, pas_astate_new);
	255
d4019f0a	256	ppc_proc_freq = pas_freqs[pas_astate_new].frequency * 1000ul;
2e0c3370 OJ	257	return 0;
	258	}
	259
	260	static struct cpufreq_driver pas_cpufreq_driver = {
	261	.name = "pas-cpufreq",
2e0c3370 OJ	262	.flags = CPUFREQ_CONST_LOOPS,
	263	.init = pas_cpufreq_cpu_init,
	264	.exit = pas_cpufreq_cpu_exit,
57174310	265	.verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7	266	.target_index = pas_cpufreq_target,
57174310	267	.attr = cpufreq_generic_attr,
2e0c3370 OJ	268	};
	269
	270	/*
	271	* module init and destoy
	272	*/
	273
	274	static int __init pas_cpufreq_init(void)
	275	{
71a157e8 GL	276	if (!of_machine_is_compatible("PA6T-1682M") &&
71a157e8 GL	277	!of_machine_is_compatible("pasemi,pwrficient"))
2e0c3370 OJ	278	return -ENODEV;
	279
	280	return cpufreq_register_driver(&pas_cpufreq_driver);
	281	}
	282
	283	static void __exit pas_cpufreq_exit(void)
	284	{
	285	cpufreq_unregister_driver(&pas_cpufreq_driver);
	286	}
	287
	288	module_init(pas_cpufreq_init);
	289	module_exit(pas_cpufreq_exit);
	290
	291	MODULE_LICENSE("GPL");
	292	MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");