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 */
36 static u64 MIC_Slow_Fast_Timer_table[] = {
37 [0 ... 7] = 0x007fc00000000000ull,
38 };
39
40 /* more values for the MIC */
41 static 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
cbe_cpufreq_set_pmode(int cpu,unsigned int pmode)53 int 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
cbe_cpufreq_get_pmode(int cpu)105 int 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
