1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * pervasive backend for the cbe_cpufreq driver |
4 | * |
5 | * This driver makes use of the pervasive unit to |
6 | * engage the desired frequency. |
7 | * |
8 | * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007 |
9 | * |
10 | * Author: Christian Krafft <krafft@de.ibm.com> |
11 | */ |
12 | |
13 | #include <linux/io.h> |
14 | #include <linux/kernel.h> |
15 | #include <linux/time.h> |
16 | #include <asm/machdep.h> |
17 | #include <asm/hw_irq.h> |
18 | #include <asm/cell-regs.h> |
19 | |
20 | #include "ppc_cbe_cpufreq.h" |
21 | |
22 | /* to write to MIC register */ |
23 | static u64 MIC_Slow_Fast_Timer_table[] = { |
24 | [0 ... 7] = 0x007fc00000000000ull, |
25 | }; |
26 | |
27 | /* more values for the MIC */ |
28 | static u64 MIC_Slow_Next_Timer_table[] = { |
29 | 0x0000240000000000ull, |
30 | 0x0000268000000000ull, |
31 | 0x000029C000000000ull, |
32 | 0x00002D0000000000ull, |
33 | 0x0000300000000000ull, |
34 | 0x0000334000000000ull, |
35 | 0x000039C000000000ull, |
36 | 0x00003FC000000000ull, |
37 | }; |
38 | |
39 | |
40 | int cbe_cpufreq_set_pmode(int cpu, unsigned int pmode) |
41 | { |
42 | struct cbe_pmd_regs __iomem *pmd_regs; |
43 | struct cbe_mic_tm_regs __iomem *mic_tm_regs; |
44 | unsigned long flags; |
45 | u64 value; |
46 | #ifdef DEBUG |
47 | long time; |
48 | #endif |
49 | |
50 | local_irq_save(flags); |
51 | |
52 | mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu); |
53 | pmd_regs = cbe_get_cpu_pmd_regs(cpu); |
54 | |
55 | #ifdef DEBUG |
56 | time = jiffies; |
57 | #endif |
58 | |
59 | out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]); |
60 | out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]); |
61 | |
62 | out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]); |
63 | out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]); |
64 | |
65 | value = in_be64(&pmd_regs->pmcr); |
66 | /* set bits to zero */ |
67 | value &= 0xFFFFFFFFFFFFFFF8ull; |
68 | /* set bits to next pmode */ |
69 | value |= pmode; |
70 | |
71 | out_be64(&pmd_regs->pmcr, value); |
72 | |
73 | #ifdef DEBUG |
74 | /* wait until new pmode appears in status register */ |
75 | value = in_be64(&pmd_regs->pmsr) & 0x07; |
76 | while (value != pmode) { |
77 | cpu_relax(); |
78 | value = in_be64(&pmd_regs->pmsr) & 0x07; |
79 | } |
80 | |
81 | time = jiffies - time; |
82 | time = jiffies_to_msecs(time); |
83 | pr_debug("had to wait %lu ms for a transition using " \ |
84 | "pervasive unit\n" , time); |
85 | #endif |
86 | local_irq_restore(flags); |
87 | |
88 | return 0; |
89 | } |
90 | |
91 | |
92 | int cbe_cpufreq_get_pmode(int cpu) |
93 | { |
94 | int ret; |
95 | struct cbe_pmd_regs __iomem *pmd_regs; |
96 | |
97 | pmd_regs = cbe_get_cpu_pmd_regs(cpu); |
98 | ret = in_be64(&pmd_regs->pmsr) & 0x07; |
99 | |
100 | return ret; |
101 | } |
102 | |
103 | |