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

/*
 * cpufreq driver for the cell processor
 *
 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
 *
 * 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 <linux/timer.h>

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

#include "cbe_regs.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},
};

/* to write to MIC register */
static u64 MIC_Slow_Fast_Timer_table[] = {
	[0 ... 7] = 0x007fc00000000000ull,
};

/* more values for the MIC */
static u64 MIC_Slow_Next_Timer_table[] = {
	0x0000240000000000ull,
	0x0000268000000000ull,
	0x000029C000000000ull,
	0x00002D0000000000ull,
	0x0000300000000000ull,
	0x0000334000000000ull,
	0x000039C000000000ull,
	0x00003FC000000000ull,
};

/*
 * hardware specific functions
 */

static int get_pmode(int cpu)
{
	int ret;
	struct cbe_pmd_regs __iomem *pmd_regs;

	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
	ret = in_be64(&pmd_regs->pmsr) & 0x07;

	return ret;
}

static int set_pmode(int cpu, unsigned int pmode)
{
	struct cbe_pmd_regs __iomem *pmd_regs;
	struct cbe_mic_tm_regs __iomem *mic_tm_regs;
	u64 flags;
	u64 value;

	local_irq_save(flags);

	mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
	pmd_regs = cbe_get_cpu_pmd_regs(cpu);

	pr_debug("pm register is mapped at %p\n", &pmd_regs->pmcr);
	pr_debug("mic register is mapped at %p\n", &mic_tm_regs->slow_fast_timer_0);

	out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]);
	out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]);

	out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]);
	out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]);

	value = in_be64(&pmd_regs->pmcr);
	/* set bits to zero */
	value &= 0xFFFFFFFFFFFFFFF8ull;
	/* set bits to next pmode */
	value |= pmode;

	out_be64(&pmd_regs->pmcr, value);

	/* wait until new pmode appears in status register */
	value = in_be64(&pmd_regs->pmsr) & 0x07;
	while(value != pmode) {
		cpu_relax();
		value = in_be64(&pmd_regs->pmsr) & 0x07;
	}

	local_irq_restore(flags);

	return 0;
}

/*
 * cpufreq functions
 */

static int cbe_cpufreq_cpu_init (struct cpufreq_policy *policy)
{
	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);

	max_freq = (u32*) get_property(cpu, "clock-frequency", NULL);

	if(!max_freq)
		return -EINVAL;

	// we need the freq in kHz
	*max_freq /= 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);
	}

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

	cur_pmode = 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;
	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)
{
	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	*
	4	* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
	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>
	24	#include <linux/timer.h>
	25
	26	#include <asm/hw_irq.h>
	27	#include <asm/io.h>
	28	#include <asm/processor.h>
	29	#include <asm/prom.h>
	30	#include <asm/time.h>
	31
	32	#include "cbe_regs.h"
	33
	34	static DEFINE_MUTEX(cbe_switch_mutex);
	35
	36
	37	/* the CBE supports an 8 step frequency scaling */
	38	static struct cpufreq_frequency_table cbe_freqs[] = {
	39	{1, 0},
	40	{2, 0},
	41	{3, 0},
	42	{4, 0},
	43	{5, 0},
	44	{6, 0},
	45	{8, 0},
	46	{10, 0},
	47	{0, CPUFREQ_TABLE_END},
	48	};
	49
	50	/* to write to MIC register */
	51	static u64 MIC_Slow_Fast_Timer_table[] = {
	52	[0 ... 7] = 0x007fc00000000000ull,
	53	};
	54
	55	/* more values for the MIC */
	56	static u64 MIC_Slow_Next_Timer_table[] = {
	57	0x0000240000000000ull,
	58	0x0000268000000000ull,
	59	0x000029C000000000ull,
	60	0x00002D0000000000ull,
	61	0x0000300000000000ull,
	62	0x0000334000000000ull,
	63	0x000039C000000000ull,
	64	0x00003FC000000000ull,
65	};
66
67	/*
68	* hardware specific functions
69	*/
70
71	static int get_pmode(int cpu)
72	{
73	int ret;
74	struct cbe_pmd_regs __iomem *pmd_regs;
75
76	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
77	ret = in_be64(&pmd_regs->pmsr) & 0x07;
78
79	return ret;
80	}
81
82	static int set_pmode(int cpu, unsigned int pmode)
83	{
84	struct cbe_pmd_regs __iomem *pmd_regs;
85	struct cbe_mic_tm_regs __iomem *mic_tm_regs;
86	u64 flags;
87	u64 value;
88
89	local_irq_save(flags);
90
91	mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
92	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
93
94	pr_debug("pm register is mapped at %p\n", &pmd_regs->pmcr);
95	pr_debug("mic register is mapped at %p\n", &mic_tm_regs->slow_fast_timer_0);
96
97	out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]);
98	out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]);
99
100	out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]);
101	out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]);
102
103	value = in_be64(&pmd_regs->pmcr);
104	/* set bits to zero */
105	value &= 0xFFFFFFFFFFFFFFF8ull;
106	/* set bits to next pmode */
107	value \|= pmode;
108
109	out_be64(&pmd_regs->pmcr, value);
110
111	/* wait until new pmode appears in status register */
112	value = in_be64(&pmd_regs->pmsr) & 0x07;
113	while(value != pmode) {
114	cpu_relax();
115	value = in_be64(&pmd_regs->pmsr) & 0x07;
116	}
117
118	local_irq_restore(flags);
119
120	return 0;
121	}
122
123	/*
124	* cpufreq functions
125	*/
126
127	static int cbe_cpufreq_cpu_init (struct cpufreq_policy *policy)
128	{
129	u32 *max_freq;
130	int i, cur_pmode;
131	struct device_node *cpu;
132
133	cpu = of_get_cpu_node(policy->cpu, NULL);
134
135	if(!cpu)
136	return -ENODEV;
137
138	pr_debug("init cpufreq on CPU %d\n", policy->cpu);
139
140	max_freq = (u32*) get_property(cpu, "clock-frequency", NULL);
141
142	if(!max_freq)
143	return -EINVAL;
144
145	// we need the freq in kHz
146	*max_freq /= 1000;
147
148	pr_debug("max clock-frequency is at %u kHz\n", *max_freq);
149	pr_debug("initializing frequency table\n");
150
151	// initialize frequency table
152	for (i=0; cbe_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
153	cbe_freqs[i].frequency = *max_freq / cbe_freqs[i].index;
154	pr_debug("%d: %d\n", i, cbe_freqs[i].frequency);
155	}
156
157	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
158	/* if DEBUG is enabled set_pmode() measures the correct latency of a transition */
159	policy->cpuinfo.transition_latency = 25000;
160
161	cur_pmode = get_pmode(policy->cpu);
162	pr_debug("current pmode is at %d\n",cur_pmode);
163
164	policy->cur = cbe_freqs[cur_pmode].frequency;
165
166	#ifdef CONFIG_SMP
167	policy->cpus = cpu_sibling_map[policy->cpu];
168	#endif
169
170	cpufreq_frequency_table_get_attr (cbe_freqs, policy->cpu);
171
172	/* this ensures that policy->cpuinfo_min and policy->cpuinfo_max are set correctly */
173	return cpufreq_frequency_table_cpuinfo (policy, cbe_freqs);
174	}
175
176	static int cbe_cpufreq_cpu_exit(struct cpufreq_policy *policy)
177	{
178	cpufreq_frequency_table_put_attr(policy->cpu);
179	return 0;
180	}
181
182	static int cbe_cpufreq_verify(struct cpufreq_policy *policy)
183	{
184	return cpufreq_frequency_table_verify(policy, cbe_freqs);
185	}
186
187
188	static int cbe_cpufreq_target(struct cpufreq_policy *policy, unsigned int target_freq,
189	unsigned int relation)
190	{
191	int rc;
192	struct cpufreq_freqs freqs;
193	int cbe_pmode_new;
194
195	cpufreq_frequency_table_target(policy,
196	cbe_freqs,
197	target_freq,
198	relation,
199	&cbe_pmode_new);
200
201	freqs.old = policy->cur;
202	freqs.new = cbe_freqs[cbe_pmode_new].frequency;
203	freqs.cpu = policy->cpu;
204
205	mutex_lock (&cbe_switch_mutex);
206	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
207
208	pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n",
209	policy->cpu,
210	cbe_freqs[cbe_pmode_new].frequency,
211	cbe_freqs[cbe_pmode_new].index);
212
213	rc = set_pmode(policy->cpu, cbe_pmode_new);
214	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
215	mutex_unlock(&cbe_switch_mutex);
216
217	return rc;
218	}
219
220	static struct cpufreq_driver cbe_cpufreq_driver = {
221	.verify = cbe_cpufreq_verify,
222	.target = cbe_cpufreq_target,
223	.init = cbe_cpufreq_cpu_init,
224	.exit = cbe_cpufreq_cpu_exit,
225	.name = "cbe-cpufreq",
226	.owner = THIS_MODULE,
227	.flags = CPUFREQ_CONST_LOOPS,
228	};
229
230	/*
231	* module init and destoy
232	*/
233
234	static int __init cbe_cpufreq_init(void)
235	{
236	return cpufreq_register_driver(&cbe_cpufreq_driver);
237	}
238
239	static void __exit cbe_cpufreq_exit(void)
240	{
241	cpufreq_unregister_driver(&cbe_cpufreq_driver);
242	}
243
244	module_init(cbe_cpufreq_init);
245	module_exit(cbe_cpufreq_exit);
246
247	MODULE_LICENSE("GPL");
248	MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");