summaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
blob: d29e8da396a040013bece00cb2ac1c1b1d587137 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/*
 * pmi backend for the cbe_cpufreq driver
 *
 * (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/kernel.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/module.h>
#include <linux/of_platform.h>

#include <asm/processor.h>
#include <asm/prom.h>
#include <asm/pmi.h>
#include <asm/cell-regs.h>

#ifdef DEBUG
#include <asm/time.h>
#endif

#include "ppc_cbe_cpufreq.h"

static u8 pmi_slow_mode_limit[MAX_CBE];

bool cbe_cpufreq_has_pmi = false;
EXPORT_SYMBOL_GPL(cbe_cpufreq_has_pmi);

/*
 * hardware specific functions
 */

int cbe_cpufreq_set_pmode_pmi(int cpu, unsigned int pmode)
{
	int ret;
	pmi_message_t pmi_msg;
#ifdef DEBUG
	long time;
#endif
	pmi_msg.type = PMI_TYPE_FREQ_CHANGE;
	pmi_msg.data1 =	cbe_cpu_to_node(cpu);
	pmi_msg.data2 = pmode;

#ifdef DEBUG
	time = jiffies;
#endif
	pmi_send_message(pmi_msg);

#ifdef DEBUG
	time = jiffies  - time;
	time = jiffies_to_msecs(time);
	pr_debug("had to wait %lu ms for a transition using " \
		 "PMI\n", time);
#endif
	ret = pmi_msg.data2;
	pr_debug("PMI returned slow mode %d\n", ret);

	return ret;
}
EXPORT_SYMBOL_GPL(cbe_cpufreq_set_pmode_pmi);


static void cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg)
{
	u8 node, slow_mode;

	BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE);

	node = pmi_msg.data1;
	slow_mode = pmi_msg.data2;

	pmi_slow_mode_limit[node] = slow_mode;

	pr_debug("cbe_handle_pmi: node: %d max_freq: %d\n", node, slow_mode);
}

static int pmi_notifier(struct notifier_block *nb,
				       unsigned long event, void *data)
{
	struct cpufreq_policy *policy = data;
	struct cpufreq_frequency_table *cbe_freqs;
	u8 node;

	/* Should this really be called for CPUFREQ_ADJUST, CPUFREQ_INCOMPATIBLE
	 * and CPUFREQ_NOTIFY policy events?)
	 */
	if (event == CPUFREQ_START)
		return 0;

	cbe_freqs = cpufreq_frequency_get_table(policy->cpu);
	node = cbe_cpu_to_node(policy->cpu);

	pr_debug("got notified, event=%lu, node=%u\n", event, node);

	if (pmi_slow_mode_limit[node] != 0) {
		pr_debug("limiting node %d to slow mode %d\n",
			 node, pmi_slow_mode_limit[node]);

		cpufreq_verify_within_limits(policy, 0,

			cbe_freqs[pmi_slow_mode_limit[node]].frequency);
	}

	return 0;
}

static struct notifier_block pmi_notifier_block = {
	.notifier_call = pmi_notifier,
};

static struct pmi_handler cbe_pmi_handler = {
	.type			= PMI_TYPE_FREQ_CHANGE,
	.handle_pmi_message	= cbe_cpufreq_handle_pmi,
};



static int __init cbe_cpufreq_pmi_init(void)
{
	cbe_cpufreq_has_pmi = pmi_register_handler(&cbe_pmi_handler) == 0;

	if (!cbe_cpufreq_has_pmi)
		return -ENODEV;

	cpufreq_register_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);

	return 0;
}

static void __exit cbe_cpufreq_pmi_exit(void)
{
	cpufreq_unregister_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);
	pmi_unregister_handler(&cbe_pmi_handler);
}

module_init(cbe_cpufreq_pmi_init);
module_exit(cbe_cpufreq_pmi_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");