[mirror_ubuntu-zesty-kernel.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 <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;

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)
{
	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);
	}

	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;
	cpumask_copy(policy->cpus, cpu_online_mask);

	ppc_proc_freq = policy->cur * 1000ul;

	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)
{
	/*
	 * 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_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;

	mutex_lock(&pas_switch_mutex);
	cpufreq_notify_transition(policy, &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].driver_data);

	current_astate = pas_astate_new;

	for_each_online_cpu(i)
		set_astate(i, pas_astate_new);

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

	ppc_proc_freq = freqs.new * 1000ul;
	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 (!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>
2e0c3370 OJ	31
	32	#include <asm/hw_irq.h>
	33	#include <asm/io.h>
	34	#include <asm/prom.h>
2abb7019	35	#include <asm/time.h>
8b32bc03	36	#include <asm/smp.h>
2e0c3370 OJ	37
	38	#define SDCASR_REG 0x0100
	39	#define SDCASR_REG_STRIDE 0x1000
	40	#define SDCPWR_CFGA0_REG 0x0100
	41	#define SDCPWR_PWST0_REG 0x0000
	42	#define SDCPWR_GIZTIME_REG 0x0440
	43
	44	/* SDCPWR_GIZTIME_REG fields */
	45	#define SDCPWR_GIZTIME_GR 0x80000000
	46	#define SDCPWR_GIZTIME_LONGLOCK 0x000000ff
	47
	48	/* Offset of ASR registers from SDC base */
	49	#define SDCASR_OFFSET 0x120000
	50
	51	static void __iomem *sdcpwr_mapbase;
	52	static void __iomem *sdcasr_mapbase;
	53
	54	static DEFINE_MUTEX(pas_switch_mutex);
	55
	56	/* Current astate, is used when waking up from power savings on
	57	* one core, in case the other core has switched states during
	58	* the idle time.
	59	*/
	60	static int current_astate;
	61
	62	/* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
	63	static struct cpufreq_frequency_table pas_freqs[] = {
	64	{0, 0},
	65	{1, 0},
	66	{2, 0},
	67	{3, 0},
	68	{4, 0},
	69	{0, CPUFREQ_TABLE_END},
	70	};
	71
	72	static struct freq_attr *pas_cpu_freqs_attr[] = {
	73	&cpufreq_freq_attr_scaling_available_freqs,
	74	NULL,
	75	};
	76
	77	/*
	78	* hardware specific functions
	79	*/
	80
	81	static int get_astate_freq(int astate)
	82	{
	83	u32 ret;
	84	ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10));
	85
	86	return ret & 0x3f;
	87	}
	88
	89	static int get_cur_astate(int cpu)
	90	{
	91	u32 ret;
	92
	93	ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG);
	94	ret = (ret >> (cpu * 4)) & 0x7;
	95
	96	return ret;
	97	}
	98
	99	static int get_gizmo_latency(void)
	100	{
101	u32 giztime, ret;
102
103	giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG);
104
105	/* just provide the upper bound */
106	if (giztime & SDCPWR_GIZTIME_GR)
107	ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000;
108	else
109	ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000;
110
111	return ret;
112	}
113
114	static void set_astate(int cpu, unsigned int astate)
115	{
ac3f6454	116	unsigned long flags;
2e0c3370 OJ	117
	118	/* Return if called before init has run */
	119	if (unlikely(!sdcasr_mapbase))
	120	return;
	121
	122	local_irq_save(flags);
	123
	124	out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate);
	125
	126	local_irq_restore(flags);
	127	}
	128
8b32bc03 OJ	129	int check_astate(void)
	130	{
	131	return get_cur_astate(hard_smp_processor_id());
	132	}
	133
2e0c3370 OJ	134	void restore_astate(int cpu)
	135	{
	136	set_astate(cpu, current_astate);
	137	}
	138
	139	/*
	140	* cpufreq functions
	141	*/
	142
	143	static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
	144	{
12d371a6 SR	145	const u32 *max_freqp;
12d371a6 SR	146	u32 max_freq;
2e0c3370 OJ	147	int i, cur_astate;
	148	struct resource res;
	149	struct device_node cpu, dn;
	150	int err = -ENODEV;
	151
	152	cpu = of_get_cpu_node(policy->cpu, NULL);
	153
	154	if (!cpu)
	155	goto out;
	156
0d08a847 OJ	157	dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
	158	if (!dn)
	159	dn = of_find_compatible_node(NULL, NULL,
	160	"pasemi,pwrficient-sdc");
2e0c3370 OJ	161	if (!dn)
	162	goto out;
	163	err = of_address_to_resource(dn, 0, &res);
	164	of_node_put(dn);
	165	if (err)
	166	goto out;
	167	sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000);
	168	if (!sdcasr_mapbase) {
	169	err = -EINVAL;
	170	goto out;
	171	}
	172
0d08a847 OJ	173	dn = of_find_compatible_node(NULL, NULL, "1682m-gizmo");
	174	if (!dn)
	175	dn = of_find_compatible_node(NULL, NULL,
	176	"pasemi,pwrficient-gizmo");
2e0c3370 OJ	177	if (!dn) {
	178	err = -ENODEV;
	179	goto out_unmap_sdcasr;
	180	}
	181	err = of_address_to_resource(dn, 0, &res);
	182	of_node_put(dn);
	183	if (err)
	184	goto out_unmap_sdcasr;
	185	sdcpwr_mapbase = ioremap(res.start, 0x1000);
	186	if (!sdcpwr_mapbase) {
	187	err = -EINVAL;
	188	goto out_unmap_sdcasr;
	189	}
	190
	191	pr_debug("init cpufreq on CPU %d\n", policy->cpu);
	192
12d371a6 SR	193	max_freqp = of_get_property(cpu, "clock-frequency", NULL);
12d371a6 SR	194	if (!max_freqp) {
2e0c3370 OJ	195	err = -EINVAL;
	196	goto out_unmap_sdcpwr;
	197	}
	198
	199	/* we need the freq in kHz */
12d371a6	200	max_freq = *max_freqp / 1000;
2e0c3370	201
12d371a6	202	pr_debug("max clock-frequency is at %u kHz\n", max_freq);
2e0c3370 OJ	203	pr_debug("initializing frequency table\n");
	204
	205	/* initialize frequency table */
	206	for (i=0; pas_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
50701588 VK	207	pas_freqs[i].frequency =
50701588 VK	208	get_astate_freq(pas_freqs[i].driver_data) * 100000;
2e0c3370 OJ	209	pr_debug("%d: %d\n", i, pas_freqs[i].frequency);
	210	}
	211
2e0c3370 OJ	212	policy->cpuinfo.transition_latency = get_gizmo_latency();
	213
	214	cur_astate = get_cur_astate(policy->cpu);
	215	pr_debug("current astate is at %d\n",cur_astate);
	216
	217	policy->cur = pas_freqs[cur_astate].frequency;
1b095cf4	218	cpumask_copy(policy->cpus, cpu_online_mask);
2e0c3370	219
2abb7019 OJ	220	ppc_proc_freq = policy->cur * 1000ul;
2abb7019 OJ	221
2e0c3370 OJ	222	cpufreq_frequency_table_get_attr(pas_freqs, policy->cpu);
	223
	224	/* this ensures that policy->cpuinfo_min and policy->cpuinfo_max
	225	* are set correctly
	226	*/
	227	return cpufreq_frequency_table_cpuinfo(policy, pas_freqs);
	228
	229	out_unmap_sdcpwr:
	230	iounmap(sdcpwr_mapbase);
	231
	232	out_unmap_sdcasr:
	233	iounmap(sdcasr_mapbase);
	234	out:
	235	return err;
	236	}
	237
	238	static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)
	239	{
72640d88 SR	240	/*
	241	* We don't support CPU hotplug. Don't unmap after the system
	242	* has already made it to a running state.
	243	*/
	244	if (system_state != SYSTEM_BOOTING)
	245	return 0;
	246
2e0c3370 OJ	247	if (sdcasr_mapbase)
	248	iounmap(sdcasr_mapbase);
	249	if (sdcpwr_mapbase)
	250	iounmap(sdcpwr_mapbase);
	251
	252	cpufreq_frequency_table_put_attr(policy->cpu);
	253	return 0;
	254	}
	255
	256	static int pas_cpufreq_verify(struct cpufreq_policy *policy)
	257	{
	258	return cpufreq_frequency_table_verify(policy, pas_freqs);
	259	}
	260
	261	static int pas_cpufreq_target(struct cpufreq_policy *policy,
	262	unsigned int target_freq,
	263	unsigned int relation)
	264	{
	265	struct cpufreq_freqs freqs;
	266	int pas_astate_new;
	267	int i;
	268
	269	cpufreq_frequency_table_target(policy,
	270	pas_freqs,
	271	target_freq,
	272	relation,
	273	&pas_astate_new);
	274
	275	freqs.old = policy->cur;
	276	freqs.new = pas_freqs[pas_astate_new].frequency;
2e0c3370 OJ	277
2e0c3370 OJ	278	mutex_lock(&pas_switch_mutex);
b43a7ffb	279	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
2e0c3370 OJ	280
	281	pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n",
	282	policy->cpu,
	283	pas_freqs[pas_astate_new].frequency,
50701588	284	pas_freqs[pas_astate_new].driver_data);
2e0c3370 OJ	285
	286	current_astate = pas_astate_new;
	287
	288	for_each_online_cpu(i)
	289	set_astate(i, pas_astate_new);
	290
b43a7ffb	291	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
2e0c3370 OJ	292	mutex_unlock(&pas_switch_mutex);
2e0c3370 OJ	293
2abb7019	294	ppc_proc_freq = freqs.new * 1000ul;
2e0c3370 OJ	295	return 0;
	296	}
	297
	298	static struct cpufreq_driver pas_cpufreq_driver = {
	299	.name = "pas-cpufreq",
	300	.owner = THIS_MODULE,
	301	.flags = CPUFREQ_CONST_LOOPS,
	302	.init = pas_cpufreq_cpu_init,
	303	.exit = pas_cpufreq_cpu_exit,
	304	.verify = pas_cpufreq_verify,
	305	.target = pas_cpufreq_target,
	306	.attr = pas_cpu_freqs_attr,
	307	};
	308
	309	/*
	310	* module init and destoy
	311	*/
	312
	313	static int __init pas_cpufreq_init(void)
	314	{
71a157e8 GL	315	if (!of_machine_is_compatible("PA6T-1682M") &&
71a157e8 GL	316	!of_machine_is_compatible("pasemi,pwrficient"))
2e0c3370 OJ	317	return -ENODEV;
	318
	319	return cpufreq_register_driver(&pas_cpufreq_driver);
	320	}
	321
	322	static void __exit pas_cpufreq_exit(void)
	323	{
	324	cpufreq_unregister_driver(&pas_cpufreq_driver);
	325	}
	326
	327	module_init(pas_cpufreq_init);
	328	module_exit(pas_cpufreq_exit);
	329
	330	MODULE_LICENSE("GPL");
	331	MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");