[deliverable/linux.git] / arch / powerpc / platforms / cell / cbe_cpufreq.c

/*
 * cpufreq driver for the cell processor
 *
 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
 *
 * Author: Christian Krafft <krafft@de.ibm.com>
 *
 * 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 <asm/machdep.h>
#include <asm/of_platform.h>
#include <asm/prom.h>
#include <asm/cell-regs.h>
#include "cbe_cpufreq.h"

static DEFINE_MUTEX(cbe_switch_mutex);


/* the CBE supports an 8 step frequency scaling */
static struct cpufreq_frequency_table cbe_freqs[] = {
	{1,	0},
	{2,	0},
	{3,	0},
	{4,	0},
	{5,	0},
	{6,	0},
	{8,	0},
	{10,	0},
	{0,	CPUFREQ_TABLE_END},
};

/*
 * hardware specific functions
 */

static int set_pmode(unsigned int cpu, unsigned int slow_mode)
{
	int rc;

	if (cbe_cpufreq_has_pmi)
		rc = cbe_cpufreq_set_pmode_pmi(cpu, slow_mode);
	else
		rc = cbe_cpufreq_set_pmode(cpu, slow_mode);

	pr_debug("register contains slow mode %d\n", cbe_cpufreq_get_pmode(cpu));

	return rc;
}

/*
 * cpufreq functions
 */

static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
	const u32 *max_freqp;
	u32 max_freq;
	int i, cur_pmode;
	struct device_node *cpu;

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

	if (!cpu)
		return -ENODEV;

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

	/*
	 * Let's check we can actually get to the CELL regs
	 */
	if (!cbe_get_cpu_pmd_regs(policy->cpu) ||
	    !cbe_get_cpu_mic_tm_regs(policy->cpu)) {
		pr_info("invalid CBE regs pointers for cpufreq\n");
		return -EINVAL;
	}

	max_freqp = of_get_property(cpu, "clock-frequency", NULL);

	of_node_put(cpu);

	if (!max_freqp)
		return -EINVAL;

	/* 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; cbe_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
		cbe_freqs[i].frequency = max_freq / cbe_freqs[i].index;
		pr_debug("%d: %d\n", i, cbe_freqs[i].frequency);
	}

	/* if DEBUG is enabled set_pmode() measures the latency
	 * of a transition */
	policy->cpuinfo.transition_latency = 25000;

	cur_pmode = cbe_cpufreq_get_pmode(policy->cpu);
	pr_debug("current pmode is at %d\n",cur_pmode);

	policy->cur = cbe_freqs[cur_pmode].frequency;

#ifdef CONFIG_SMP
	policy->cpus = cpu_sibling_map[policy->cpu];
#endif

	cpufreq_frequency_table_get_attr(cbe_freqs, policy->cpu);

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

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

static int cbe_cpufreq_verify(struct cpufreq_policy *policy)
{
	return cpufreq_frequency_table_verify(policy, cbe_freqs);
}

static int cbe_cpufreq_target(struct cpufreq_policy *policy,
			      unsigned int target_freq,
			      unsigned int relation)
{
	int rc;
	struct cpufreq_freqs freqs;
	unsigned int cbe_pmode_new;

	cpufreq_frequency_table_target(policy,
				       cbe_freqs,
				       target_freq,
				       relation,
				       &cbe_pmode_new);

	freqs.old = policy->cur;
	freqs.new = cbe_freqs[cbe_pmode_new].frequency;
	freqs.cpu = policy->cpu;

	mutex_lock(&cbe_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,
		 cbe_freqs[cbe_pmode_new].frequency,
		 cbe_freqs[cbe_pmode_new].index);

	rc = set_pmode(policy->cpu, cbe_pmode_new);

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

	return rc;
}

static struct cpufreq_driver cbe_cpufreq_driver = {
	.verify		= cbe_cpufreq_verify,
	.target		= cbe_cpufreq_target,
	.init		= cbe_cpufreq_cpu_init,
	.exit		= cbe_cpufreq_cpu_exit,
	.name		= "cbe-cpufreq",
	.owner		= THIS_MODULE,
	.flags		= CPUFREQ_CONST_LOOPS,
};

/*
 * module init and destoy
 */

static int __init cbe_cpufreq_init(void)
{
	if (!machine_is(cell))
		return -ENODEV;

	return cpufreq_register_driver(&cbe_cpufreq_driver);
}

static void __exit cbe_cpufreq_exit(void)
{
	cpufreq_unregister_driver(&cbe_cpufreq_driver);
}

module_init(cbe_cpufreq_init);
module_exit(cbe_cpufreq_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
Commit	Line	Data
36ca4ba4 CK	1	/*
	2	* cpufreq driver for the cell processor
	3	*
74889e41	4	* (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
36ca4ba4 CK	5	*
	6	* Author: Christian Krafft <krafft@de.ibm.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2, or (at your option)
	11	* any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	21	*/
	22
	23	#include <linux/cpufreq.h>
4bd4aa19	24	#include <asm/machdep.h>
5050063c	25	#include <asm/of_platform.h>
74889e41	26	#include <asm/prom.h>
eef686a0	27	#include <asm/cell-regs.h>
74889e41	28	#include "cbe_cpufreq.h"
36ca4ba4 CK	29
	30	static DEFINE_MUTEX(cbe_switch_mutex);
	31
	32
	33	/* the CBE supports an 8 step frequency scaling */
	34	static struct cpufreq_frequency_table cbe_freqs[] = {
	35	{1, 0},
	36	{2, 0},
	37	{3, 0},
	38	{4, 0},
	39	{5, 0},
	40	{6, 0},
	41	{8, 0},
	42	{10, 0},
	43	{0, CPUFREQ_TABLE_END},
	44	};
	45
36ca4ba4 CK	46	/*
	47	* hardware specific functions
	48	*/
	49
74889e41	50	static int set_pmode(unsigned int cpu, unsigned int slow_mode)
813f9072	51	{
1e21fd5a	52	int rc;
74889e41	53
813f9072	54	if (cbe_cpufreq_has_pmi)
74889e41	55	rc = cbe_cpufreq_set_pmode_pmi(cpu, slow_mode);
1e21fd5a	56	else
74889e41	57	rc = cbe_cpufreq_set_pmode(cpu, slow_mode);
1e21fd5a	58
74889e41	59	pr_debug("register contains slow mode %d\n", cbe_cpufreq_get_pmode(cpu));
1e21fd5a CK	60
1e21fd5a CK	61	return rc;
5050063c CK	62	}
5050063c CK	63
36ca4ba4 CK	64	/*
	65	* cpufreq functions
	66	*/
	67
4bd4aa19	68	static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy)
36ca4ba4	69	{
9c1a2bae SR	70	const u32 *max_freqp;
9c1a2bae SR	71	u32 max_freq;
36ca4ba4 CK	72	int i, cur_pmode;
	73	struct device_node *cpu;
	74
	75	cpu = of_get_cpu_node(policy->cpu, NULL);
	76
4bd4aa19	77	if (!cpu)
36ca4ba4 CK	78	return -ENODEV;
	79
	80	pr_debug("init cpufreq on CPU %d\n", policy->cpu);
	81
64bafa9d JCD	82	/*
	83	* Let's check we can actually get to the CELL regs
	84	*/
	85	if (!cbe_get_cpu_pmd_regs(policy->cpu) \|\|
	86	!cbe_get_cpu_mic_tm_regs(policy->cpu)) {
	87	pr_info("invalid CBE regs pointers for cpufreq\n");
	88	return -EINVAL;
	89	}
	90
9c1a2bae	91	max_freqp = of_get_property(cpu, "clock-frequency", NULL);
36ca4ba4	92
1e21fd5a CK	93	of_node_put(cpu);
1e21fd5a CK	94
9c1a2bae	95	if (!max_freqp)
36ca4ba4 CK	96	return -EINVAL;
36ca4ba4 CK	97
4bd4aa19	98	/* we need the freq in kHz */
9c1a2bae	99	max_freq = *max_freqp / 1000;
36ca4ba4	100
9c1a2bae	101	pr_debug("max clock-frequency is at %u kHz\n", max_freq);
36ca4ba4 CK	102	pr_debug("initializing frequency table\n");
36ca4ba4 CK	103
4bd4aa19	104	/* initialize frequency table */
36ca4ba4	105	for (i=0; cbe_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
9c1a2bae	106	cbe_freqs[i].frequency = max_freq / cbe_freqs[i].index;
36ca4ba4 CK	107	pr_debug("%d: %d\n", i, cbe_freqs[i].frequency);
	108	}
	109
1e21fd5a CK	110	/* if DEBUG is enabled set_pmode() measures the latency
1e21fd5a CK	111	* of a transition */
36ca4ba4 CK	112	policy->cpuinfo.transition_latency = 25000;
36ca4ba4 CK	113
74889e41	114	cur_pmode = cbe_cpufreq_get_pmode(policy->cpu);
36ca4ba4 CK	115	pr_debug("current pmode is at %d\n",cur_pmode);
	116
	117	policy->cur = cbe_freqs[cur_pmode].frequency;
	118
	119	#ifdef CONFIG_SMP
	120	policy->cpus = cpu_sibling_map[policy->cpu];
	121	#endif
	122
4bd4aa19	123	cpufreq_frequency_table_get_attr(cbe_freqs, policy->cpu);
36ca4ba4	124
1e21fd5a CK	125	/* this ensures that policy->cpuinfo_min
1e21fd5a CK	126	* and policy->cpuinfo_max are set correctly */
4bd4aa19	127	return cpufreq_frequency_table_cpuinfo(policy, cbe_freqs);
36ca4ba4 CK	128	}
	129
	130	static int cbe_cpufreq_cpu_exit(struct cpufreq_policy *policy)
	131	{
	132	cpufreq_frequency_table_put_attr(policy->cpu);
	133	return 0;
	134	}
	135
	136	static int cbe_cpufreq_verify(struct cpufreq_policy *policy)
	137	{
	138	return cpufreq_frequency_table_verify(policy, cbe_freqs);
	139	}
	140
1e21fd5a CK	141	static int cbe_cpufreq_target(struct cpufreq_policy *policy,
	142	unsigned int target_freq,
	143	unsigned int relation)
36ca4ba4 CK	144	{
	145	int rc;
	146	struct cpufreq_freqs freqs;
1e21fd5a	147	unsigned int cbe_pmode_new;
36ca4ba4 CK	148
	149	cpufreq_frequency_table_target(policy,
	150	cbe_freqs,
	151	target_freq,
	152	relation,
	153	&cbe_pmode_new);
	154
	155	freqs.old = policy->cur;
	156	freqs.new = cbe_freqs[cbe_pmode_new].frequency;
	157	freqs.cpu = policy->cpu;
	158
4bd4aa19	159	mutex_lock(&cbe_switch_mutex);
36ca4ba4 CK	160	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
36ca4ba4 CK	161
1e21fd5a CK	162	pr_debug("setting frequency for cpu %d to %d kHz, " \
1e21fd5a CK	163	"1/%d of max frequency\n",
36ca4ba4 CK	164	policy->cpu,
	165	cbe_freqs[cbe_pmode_new].frequency,
	166	cbe_freqs[cbe_pmode_new].index);
	167
	168	rc = set_pmode(policy->cpu, cbe_pmode_new);
1e21fd5a	169
36ca4ba4 CK	170	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	171	mutex_unlock(&cbe_switch_mutex);
	172
	173	return rc;
	174	}
	175
	176	static struct cpufreq_driver cbe_cpufreq_driver = {
	177	.verify = cbe_cpufreq_verify,
	178	.target = cbe_cpufreq_target,
	179	.init = cbe_cpufreq_cpu_init,
	180	.exit = cbe_cpufreq_cpu_exit,
	181	.name = "cbe-cpufreq",
	182	.owner = THIS_MODULE,
	183	.flags = CPUFREQ_CONST_LOOPS,
	184	};
	185
	186	/*
	187	* module init and destoy
	188	*/
	189
	190	static int __init cbe_cpufreq_init(void)
	191	{
4bd4aa19 OJ	192	if (!machine_is(cell))
4bd4aa19 OJ	193	return -ENODEV;
5050063c	194
36ca4ba4 CK	195	return cpufreq_register_driver(&cbe_cpufreq_driver);
	196	}
	197
	198	static void __exit cbe_cpufreq_exit(void)
	199	{
	200	cpufreq_unregister_driver(&cbe_cpufreq_driver);
	201	}
	202
	203	module_init(cbe_cpufreq_init);
	204	module_exit(cbe_cpufreq_exit);
	205
	206	MODULE_LICENSE("GPL");
	207	MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");