aboutsummaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms/cell/cbe_cpufreq_pervasive.c
blob: 70fa7aef5edd9a6404f0fdc7b58e57565903821e (plain) (blame)
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
/*
 * pervasive backend for the cbe_cpufreq driver
 *
 * This driver makes use of the pervasive unit to
 * engage the desired frequency.
 *
 * (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/io.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <asm/machdep.h>
#include <asm/hw_irq.h>
#include <asm/cell-regs.h>

#include "cbe_cpufreq.h"

/* 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,
};


int cbe_cpufreq_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;
#ifdef DEBUG
	long time;
#endif

	local_irq_save(flags);

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

#ifdef DEBUG
	time = jiffies;
#endif

	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);

#ifdef DEBUG
	/* 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;
	}

	time = jiffies  - time;
	time = jiffies_to_msecs(time);
	pr_debug("had to wait %lu ms for a transition using " \
		 "pervasive unit\n", time);
#endif
	local_irq_restore(flags);

	return 0;
}


int cbe_cpufreq_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;
}