1/*
2 * pervasive backend for the cbe_cpufreq driver
3 *
4 * This driver makes use of the pervasive unit to
5 * engage the desired frequency.
6 *
7 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
8 *
9 * Author: Christian Krafft <krafft@de.ibm.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
14 * any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 */
25
26#include <linux/io.h>
27#include <linux/kernel.h>
28#include <linux/time.h>
29#include <asm/machdep.h>
30#include <asm/hw_irq.h>
31#include <asm/cell-regs.h>
32
33#include "ppc_cbe_cpufreq.h"
34
35/* to write to MIC register */
36static u64 MIC_Slow_Fast_Timer_table[] = {
37	[0 ... 7] = 0x007fc00000000000ull,
38};
39
40/* more values for the MIC */
41static u64 MIC_Slow_Next_Timer_table[] = {
42	0x0000240000000000ull,
43	0x0000268000000000ull,
44	0x000029C000000000ull,
45	0x00002D0000000000ull,
46	0x0000300000000000ull,
47	0x0000334000000000ull,
48	0x000039C000000000ull,
49	0x00003FC000000000ull,
50};
51
52
53int cbe_cpufreq_set_pmode(int cpu, unsigned int pmode)
54{
55	struct cbe_pmd_regs __iomem *pmd_regs;
56	struct cbe_mic_tm_regs __iomem *mic_tm_regs;
57	unsigned long flags;
58	u64 value;
59#ifdef DEBUG
60	long time;
61#endif
62
63	local_irq_save(flags);
64
65	mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
66	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
67
68#ifdef DEBUG
69	time = jiffies;
70#endif
71
72	out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]);
73	out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]);
74
75	out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]);
76	out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]);
77
78	value = in_be64(&pmd_regs->pmcr);
79	/* set bits to zero */
80	value &= 0xFFFFFFFFFFFFFFF8ull;
81	/* set bits to next pmode */
82	value |= pmode;
83
84	out_be64(&pmd_regs->pmcr, value);
85
86#ifdef DEBUG
87	/* wait until new pmode appears in status register */
88	value = in_be64(&pmd_regs->pmsr) & 0x07;
89	while (value != pmode) {
90		cpu_relax();
91		value = in_be64(&pmd_regs->pmsr) & 0x07;
92	}
93
94	time = jiffies  - time;
95	time = jiffies_to_msecs(time);
96	pr_debug("had to wait %lu ms for a transition using " \
97		 "pervasive unit\n", time);
98#endif
99	local_irq_restore(flags);
100
101	return 0;
102}
103
104
105int cbe_cpufreq_get_pmode(int cpu)
106{
107	int ret;
108	struct cbe_pmd_regs __iomem *pmd_regs;
109
110	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
111	ret = in_be64(&pmd_regs->pmsr) & 0x07;
112
113	return ret;
114}
115
116