1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * pervasive backend for the cbe_cpufreq driver
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * This driver makes use of the pervasive unit to
6*4882a593Smuzhiyun * engage the desired frequency.
7*4882a593Smuzhiyun *
8*4882a593Smuzhiyun * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
9*4882a593Smuzhiyun *
10*4882a593Smuzhiyun * Author: Christian Krafft <krafft@de.ibm.com>
11*4882a593Smuzhiyun */
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun #include <linux/io.h>
14*4882a593Smuzhiyun #include <linux/kernel.h>
15*4882a593Smuzhiyun #include <linux/time.h>
16*4882a593Smuzhiyun #include <asm/machdep.h>
17*4882a593Smuzhiyun #include <asm/hw_irq.h>
18*4882a593Smuzhiyun #include <asm/cell-regs.h>
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun #include "ppc_cbe_cpufreq.h"
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun /* to write to MIC register */
23*4882a593Smuzhiyun static u64 MIC_Slow_Fast_Timer_table[] = {
24*4882a593Smuzhiyun [0 ... 7] = 0x007fc00000000000ull,
25*4882a593Smuzhiyun };
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun /* more values for the MIC */
28*4882a593Smuzhiyun static u64 MIC_Slow_Next_Timer_table[] = {
29*4882a593Smuzhiyun 0x0000240000000000ull,
30*4882a593Smuzhiyun 0x0000268000000000ull,
31*4882a593Smuzhiyun 0x000029C000000000ull,
32*4882a593Smuzhiyun 0x00002D0000000000ull,
33*4882a593Smuzhiyun 0x0000300000000000ull,
34*4882a593Smuzhiyun 0x0000334000000000ull,
35*4882a593Smuzhiyun 0x000039C000000000ull,
36*4882a593Smuzhiyun 0x00003FC000000000ull,
37*4882a593Smuzhiyun };
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun
cbe_cpufreq_set_pmode(int cpu,unsigned int pmode)40*4882a593Smuzhiyun int cbe_cpufreq_set_pmode(int cpu, unsigned int pmode)
41*4882a593Smuzhiyun {
42*4882a593Smuzhiyun struct cbe_pmd_regs __iomem *pmd_regs;
43*4882a593Smuzhiyun struct cbe_mic_tm_regs __iomem *mic_tm_regs;
44*4882a593Smuzhiyun unsigned long flags;
45*4882a593Smuzhiyun u64 value;
46*4882a593Smuzhiyun #ifdef DEBUG
47*4882a593Smuzhiyun long time;
48*4882a593Smuzhiyun #endif
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun local_irq_save(flags);
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
53*4882a593Smuzhiyun pmd_regs = cbe_get_cpu_pmd_regs(cpu);
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun #ifdef DEBUG
56*4882a593Smuzhiyun time = jiffies;
57*4882a593Smuzhiyun #endif
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]);
60*4882a593Smuzhiyun out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]);
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]);
63*4882a593Smuzhiyun out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]);
64*4882a593Smuzhiyun
65*4882a593Smuzhiyun value = in_be64(&pmd_regs->pmcr);
66*4882a593Smuzhiyun /* set bits to zero */
67*4882a593Smuzhiyun value &= 0xFFFFFFFFFFFFFFF8ull;
68*4882a593Smuzhiyun /* set bits to next pmode */
69*4882a593Smuzhiyun value |= pmode;
70*4882a593Smuzhiyun
71*4882a593Smuzhiyun out_be64(&pmd_regs->pmcr, value);
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun #ifdef DEBUG
74*4882a593Smuzhiyun /* wait until new pmode appears in status register */
75*4882a593Smuzhiyun value = in_be64(&pmd_regs->pmsr) & 0x07;
76*4882a593Smuzhiyun while (value != pmode) {
77*4882a593Smuzhiyun cpu_relax();
78*4882a593Smuzhiyun value = in_be64(&pmd_regs->pmsr) & 0x07;
79*4882a593Smuzhiyun }
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun time = jiffies - time;
82*4882a593Smuzhiyun time = jiffies_to_msecs(time);
83*4882a593Smuzhiyun pr_debug("had to wait %lu ms for a transition using " \
84*4882a593Smuzhiyun "pervasive unit\n", time);
85*4882a593Smuzhiyun #endif
86*4882a593Smuzhiyun local_irq_restore(flags);
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun return 0;
89*4882a593Smuzhiyun }
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun
cbe_cpufreq_get_pmode(int cpu)92*4882a593Smuzhiyun int cbe_cpufreq_get_pmode(int cpu)
93*4882a593Smuzhiyun {
94*4882a593Smuzhiyun int ret;
95*4882a593Smuzhiyun struct cbe_pmd_regs __iomem *pmd_regs;
96*4882a593Smuzhiyun
97*4882a593Smuzhiyun pmd_regs = cbe_get_cpu_pmd_regs(cpu);
98*4882a593Smuzhiyun ret = in_be64(&pmd_regs->pmsr) & 0x07;
99*4882a593Smuzhiyun
100*4882a593Smuzhiyun return ret;
101*4882a593Smuzhiyun }
102*4882a593Smuzhiyun
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