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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * cpufreq driver for the cell processor
4 *
5 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
6 *
7 * Author: Christian Krafft <krafft@de.ibm.com>
8 */
9
10#include <linux/cpufreq.h>
11#include <linux/module.h>
12#include <linux/of.h>
13
14#include <asm/machdep.h>
15#include <asm/cell-regs.h>
16
17#include "ppc_cbe_cpufreq.h"
18
19/* the CBE supports an 8 step frequency scaling */
20static struct cpufreq_frequency_table cbe_freqs[] = {
21 {0, 1, 0},
22 {0, 2, 0},
23 {0, 3, 0},
24 {0, 4, 0},
25 {0, 5, 0},
26 {0, 6, 0},
27 {0, 8, 0},
28 {0, 10, 0},
29 {0, 0, CPUFREQ_TABLE_END},
30};
31
32/*
33 * hardware specific functions
34 */
35
36static int set_pmode(unsigned int cpu, unsigned int slow_mode)
37{
38 int rc;
39
40 if (cbe_cpufreq_has_pmi)
41 rc = cbe_cpufreq_set_pmode_pmi(cpu, slow_mode);
42 else
43 rc = cbe_cpufreq_set_pmode(cpu, slow_mode);
44
45 pr_debug("register contains slow mode %d\n", cbe_cpufreq_get_pmode(cpu));
46
47 return rc;
48}
49
50/*
51 * cpufreq functions
52 */
53
54static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy)
55{
56 struct cpufreq_frequency_table *pos;
57 const u32 *max_freqp;
58 u32 max_freq;
59 int cur_pmode;
60 struct device_node *cpu;
61
62 cpu = of_get_cpu_node(policy->cpu, NULL);
63
64 if (!cpu)
65 return -ENODEV;
66
67 pr_debug("init cpufreq on CPU %d\n", policy->cpu);
68
69 /*
70 * Let's check we can actually get to the CELL regs
71 */
72 if (!cbe_get_cpu_pmd_regs(policy->cpu) ||
73 !cbe_get_cpu_mic_tm_regs(policy->cpu)) {
74 pr_info("invalid CBE regs pointers for cpufreq\n");
75 of_node_put(cpu);
76 return -EINVAL;
77 }
78
79 max_freqp = of_get_property(cpu, "clock-frequency", NULL);
80
81 of_node_put(cpu);
82
83 if (!max_freqp)
84 return -EINVAL;
85
86 /* we need the freq in kHz */
87 max_freq = *max_freqp / 1000;
88
89 pr_debug("max clock-frequency is at %u kHz\n", max_freq);
90 pr_debug("initializing frequency table\n");
91
92 /* initialize frequency table */
93 cpufreq_for_each_entry(pos, cbe_freqs) {
94 pos->frequency = max_freq / pos->driver_data;
95 pr_debug("%d: %d\n", (int)(pos - cbe_freqs), pos->frequency);
96 }
97
98 /* if DEBUG is enabled set_pmode() measures the latency
99 * of a transition */
100 policy->cpuinfo.transition_latency = 25000;
101
102 cur_pmode = cbe_cpufreq_get_pmode(policy->cpu);
103 pr_debug("current pmode is at %d\n",cur_pmode);
104
105 policy->cur = cbe_freqs[cur_pmode].frequency;
106
107#ifdef CONFIG_SMP
108 cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
109#endif
110
111 policy->freq_table = cbe_freqs;
112 cbe_cpufreq_pmi_policy_init(policy);
113 return 0;
114}
115
116static int cbe_cpufreq_cpu_exit(struct cpufreq_policy *policy)
117{
118 cbe_cpufreq_pmi_policy_exit(policy);
119 return 0;
120}
121
122static int cbe_cpufreq_target(struct cpufreq_policy *policy,
123 unsigned int cbe_pmode_new)
124{
125 pr_debug("setting frequency for cpu %d to %d kHz, " \
126 "1/%d of max frequency\n",
127 policy->cpu,
128 cbe_freqs[cbe_pmode_new].frequency,
129 cbe_freqs[cbe_pmode_new].driver_data);
130
131 return set_pmode(policy->cpu, cbe_pmode_new);
132}
133
134static struct cpufreq_driver cbe_cpufreq_driver = {
135 .verify = cpufreq_generic_frequency_table_verify,
136 .target_index = cbe_cpufreq_target,
137 .init = cbe_cpufreq_cpu_init,
138 .exit = cbe_cpufreq_cpu_exit,
139 .name = "cbe-cpufreq",
140 .flags = CPUFREQ_CONST_LOOPS,
141};
142
143/*
144 * module init and destoy
145 */
146
147static int __init cbe_cpufreq_init(void)
148{
149 int ret;
150
151 if (!machine_is(cell))
152 return -ENODEV;
153
154 cbe_cpufreq_pmi_init();
155
156 ret = cpufreq_register_driver(&cbe_cpufreq_driver);
157 if (ret)
158 cbe_cpufreq_pmi_exit();
159
160 return ret;
161}
162
163static void __exit cbe_cpufreq_exit(void)
164{
165 cpufreq_unregister_driver(&cbe_cpufreq_driver);
166 cbe_cpufreq_pmi_exit();
167}
168
169module_init(cbe_cpufreq_init);
170module_exit(cbe_cpufreq_exit);
171
172MODULE_LICENSE("GPL");
173MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
1/*
2 * cpufreq driver for the cell processor
3 *
4 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
5 *
6 * Author: Christian Krafft <krafft@de.ibm.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
11 * any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 */
22
23#include <linux/cpufreq.h>
24#include <linux/module.h>
25#include <linux/of_platform.h>
26
27#include <asm/machdep.h>
28#include <asm/prom.h>
29#include <asm/cell-regs.h>
30
31#include "ppc_cbe_cpufreq.h"
32
33/* the CBE supports an 8 step frequency scaling */
34static struct cpufreq_frequency_table cbe_freqs[] = {
35 {0, 1, 0},
36 {0, 2, 0},
37 {0, 3, 0},
38 {0, 4, 0},
39 {0, 5, 0},
40 {0, 6, 0},
41 {0, 8, 0},
42 {0, 10, 0},
43 {0, 0, CPUFREQ_TABLE_END},
44};
45
46/*
47 * hardware specific functions
48 */
49
50static int set_pmode(unsigned int cpu, unsigned int slow_mode)
51{
52 int rc;
53
54 if (cbe_cpufreq_has_pmi)
55 rc = cbe_cpufreq_set_pmode_pmi(cpu, slow_mode);
56 else
57 rc = cbe_cpufreq_set_pmode(cpu, slow_mode);
58
59 pr_debug("register contains slow mode %d\n", cbe_cpufreq_get_pmode(cpu));
60
61 return rc;
62}
63
64/*
65 * cpufreq functions
66 */
67
68static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy)
69{
70 struct cpufreq_frequency_table *pos;
71 const u32 *max_freqp;
72 u32 max_freq;
73 int cur_pmode;
74 struct device_node *cpu;
75
76 cpu = of_get_cpu_node(policy->cpu, NULL);
77
78 if (!cpu)
79 return -ENODEV;
80
81 pr_debug("init cpufreq on CPU %d\n", policy->cpu);
82
83 /*
84 * Let's check we can actually get to the CELL regs
85 */
86 if (!cbe_get_cpu_pmd_regs(policy->cpu) ||
87 !cbe_get_cpu_mic_tm_regs(policy->cpu)) {
88 pr_info("invalid CBE regs pointers for cpufreq\n");
89 return -EINVAL;
90 }
91
92 max_freqp = of_get_property(cpu, "clock-frequency", NULL);
93
94 of_node_put(cpu);
95
96 if (!max_freqp)
97 return -EINVAL;
98
99 /* we need the freq in kHz */
100 max_freq = *max_freqp / 1000;
101
102 pr_debug("max clock-frequency is at %u kHz\n", max_freq);
103 pr_debug("initializing frequency table\n");
104
105 /* initialize frequency table */
106 cpufreq_for_each_entry(pos, cbe_freqs) {
107 pos->frequency = max_freq / pos->driver_data;
108 pr_debug("%d: %d\n", (int)(pos - cbe_freqs), pos->frequency);
109 }
110
111 /* if DEBUG is enabled set_pmode() measures the latency
112 * of a transition */
113 policy->cpuinfo.transition_latency = 25000;
114
115 cur_pmode = cbe_cpufreq_get_pmode(policy->cpu);
116 pr_debug("current pmode is at %d\n",cur_pmode);
117
118 policy->cur = cbe_freqs[cur_pmode].frequency;
119
120#ifdef CONFIG_SMP
121 cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
122#endif
123
124 /* this ensures that policy->cpuinfo_min
125 * and policy->cpuinfo_max are set correctly */
126 return cpufreq_table_validate_and_show(policy, cbe_freqs);
127}
128
129static int cbe_cpufreq_target(struct cpufreq_policy *policy,
130 unsigned int cbe_pmode_new)
131{
132 pr_debug("setting frequency for cpu %d to %d kHz, " \
133 "1/%d of max frequency\n",
134 policy->cpu,
135 cbe_freqs[cbe_pmode_new].frequency,
136 cbe_freqs[cbe_pmode_new].driver_data);
137
138 return set_pmode(policy->cpu, cbe_pmode_new);
139}
140
141static struct cpufreq_driver cbe_cpufreq_driver = {
142 .verify = cpufreq_generic_frequency_table_verify,
143 .target_index = cbe_cpufreq_target,
144 .init = cbe_cpufreq_cpu_init,
145 .name = "cbe-cpufreq",
146 .flags = CPUFREQ_CONST_LOOPS,
147};
148
149/*
150 * module init and destoy
151 */
152
153static int __init cbe_cpufreq_init(void)
154{
155 if (!machine_is(cell))
156 return -ENODEV;
157
158 return cpufreq_register_driver(&cbe_cpufreq_driver);
159}
160
161static void __exit cbe_cpufreq_exit(void)
162{
163 cpufreq_unregister_driver(&cbe_cpufreq_driver);
164}
165
166module_init(cbe_cpufreq_init);
167module_exit(cbe_cpufreq_exit);
168
169MODULE_LICENSE("GPL");
170MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");