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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* us3_cpufreq.c: UltraSPARC-III cpu frequency support
2 *
3 * Copyright (C) 2003 David S. Miller (davem@redhat.com)
4 *
5 * Many thanks to Dominik Brodowski for fixing up the cpufreq
6 * infrastructure in order to make this driver easier to implement.
7 */
8
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/sched.h>
12#include <linux/smp.h>
13#include <linux/cpufreq.h>
14#include <linux/threads.h>
15#include <linux/slab.h>
16#include <linux/init.h>
17
18#include <asm/head.h>
19#include <asm/timer.h>
20
21static struct cpufreq_driver *cpufreq_us3_driver;
22
23struct us3_freq_percpu_info {
24 struct cpufreq_frequency_table table[4];
25};
26
27/* Indexed by cpu number. */
28static struct us3_freq_percpu_info *us3_freq_table;
29
30/* UltraSPARC-III has three dividers: 1, 2, and 32. These are controlled
31 * in the Safari config register.
32 */
33#define SAFARI_CFG_DIV_1 0x0000000000000000UL
34#define SAFARI_CFG_DIV_2 0x0000000040000000UL
35#define SAFARI_CFG_DIV_32 0x0000000080000000UL
36#define SAFARI_CFG_DIV_MASK 0x00000000C0000000UL
37
38static unsigned long read_safari_cfg(void)
39{
40 unsigned long ret;
41
42 __asm__ __volatile__("ldxa [%%g0] %1, %0"
43 : "=&r" (ret)
44 : "i" (ASI_SAFARI_CONFIG));
45 return ret;
46}
47
48static void write_safari_cfg(unsigned long val)
49{
50 __asm__ __volatile__("stxa %0, [%%g0] %1\n\t"
51 "membar #Sync"
52 : /* no outputs */
53 : "r" (val), "i" (ASI_SAFARI_CONFIG)
54 : "memory");
55}
56
57static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
58{
David S. Miller2cab2242005-08-18 14:35:38 -070059 unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 unsigned long ret;
61
62 switch (safari_cfg & SAFARI_CFG_DIV_MASK) {
63 case SAFARI_CFG_DIV_1:
64 ret = clock_tick / 1;
65 break;
66 case SAFARI_CFG_DIV_2:
67 ret = clock_tick / 2;
68 break;
69 case SAFARI_CFG_DIV_32:
70 ret = clock_tick / 32;
71 break;
72 default:
73 BUG();
Joe Perches6cb79b32011-06-03 14:45:23 +000074 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76 return ret;
77}
78
David S. Miller2cab2242005-08-18 14:35:38 -070079static unsigned int us3_freq_get(unsigned int cpu)
80{
81 cpumask_t cpus_allowed;
82 unsigned long reg;
83 unsigned int ret;
84
KOSAKI Motohirofb1fece2011-05-16 13:38:07 -070085 cpumask_copy(&cpus_allowed, tsk_cpus_allowed(current));
Julia Lawalld2566af2010-03-27 21:11:56 -070086 set_cpus_allowed_ptr(current, cpumask_of(cpu));
David S. Miller2cab2242005-08-18 14:35:38 -070087
88 reg = read_safari_cfg();
89 ret = get_current_freq(cpu, reg);
90
Julia Lawalld2566af2010-03-27 21:11:56 -070091 set_cpus_allowed_ptr(current, &cpus_allowed);
David S. Miller2cab2242005-08-18 14:35:38 -070092
93 return ret;
94}
95
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +053096static int us3_freq_target(struct cpufreq_policy *policy, unsigned int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -070097{
Viresh Kumarb43a7ff2013-03-24 11:56:43 +053098 unsigned int cpu = policy->cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 unsigned long new_bits, new_freq, reg;
100 cpumask_t cpus_allowed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
KOSAKI Motohirofb1fece2011-05-16 13:38:07 -0700102 cpumask_copy(&cpus_allowed, tsk_cpus_allowed(current));
Julia Lawalld2566af2010-03-27 21:11:56 -0700103 set_cpus_allowed_ptr(current, cpumask_of(cpu));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
David S. Miller2cab2242005-08-18 14:35:38 -0700105 new_freq = sparc64_get_clock_tick(cpu) / 1000;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 switch (index) {
107 case 0:
108 new_bits = SAFARI_CFG_DIV_1;
109 new_freq /= 1;
110 break;
111 case 1:
112 new_bits = SAFARI_CFG_DIV_2;
113 new_freq /= 2;
114 break;
115 case 2:
116 new_bits = SAFARI_CFG_DIV_32;
117 new_freq /= 32;
118 break;
119
120 default:
121 BUG();
Joe Perches6cb79b32011-06-03 14:45:23 +0000122 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
124 reg = read_safari_cfg();
125
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 reg &= ~SAFARI_CFG_DIV_MASK;
127 reg |= new_bits;
128 write_safari_cfg(reg);
129
Julia Lawalld2566af2010-03-27 21:11:56 -0700130 set_cpus_allowed_ptr(current, &cpus_allowed);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
132 return 0;
133}
134
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135static int __init us3_freq_cpu_init(struct cpufreq_policy *policy)
136{
137 unsigned int cpu = policy->cpu;
David S. Miller2cab2242005-08-18 14:35:38 -0700138 unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 struct cpufreq_frequency_table *table =
140 &us3_freq_table[cpu].table[0];
141
Viresh Kumar50701582013-03-30 16:25:15 +0530142 table[0].driver_data = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 table[0].frequency = clock_tick / 1;
Viresh Kumar50701582013-03-30 16:25:15 +0530144 table[1].driver_data = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 table[1].frequency = clock_tick / 2;
Viresh Kumar50701582013-03-30 16:25:15 +0530146 table[2].driver_data = 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 table[2].frequency = clock_tick / 32;
Viresh Kumar50701582013-03-30 16:25:15 +0530148 table[3].driver_data = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 table[3].frequency = CPUFREQ_TABLE_END;
150
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 policy->cpuinfo.transition_latency = 0;
152 policy->cur = clock_tick;
153
Viresh Kumarf1a707c2013-09-16 18:56:36 +0530154 return cpufreq_table_validate_and_show(policy, table);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155}
156
157static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
158{
Viresh Kumar18f130e2013-09-16 18:56:06 +0530159 if (cpufreq_us3_driver) {
160 cpufreq_frequency_table_put_attr(policy->cpu);
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530161 us3_freq_target(policy, 0);
Viresh Kumar18f130e2013-09-16 18:56:06 +0530162 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
164 return 0;
165}
166
167static int __init us3_freq_init(void)
168{
169 unsigned long manuf, impl, ver;
170 int ret;
171
David S. Millerd82ace72006-02-09 02:52:44 -0800172 if (tlb_type != cheetah && tlb_type != cheetah_plus)
173 return -ENODEV;
174
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 __asm__("rdpr %%ver, %0" : "=r" (ver));
176 manuf = ((ver >> 48) & 0xffff);
177 impl = ((ver >> 32) & 0xffff);
178
179 if (manuf == CHEETAH_MANUF &&
David S. Millerd2212bc2005-09-27 22:50:06 -0700180 (impl == CHEETAH_IMPL ||
181 impl == CHEETAH_PLUS_IMPL ||
182 impl == JAGUAR_IMPL ||
183 impl == PANTHER_IMPL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 struct cpufreq_driver *driver;
185
186 ret = -ENOMEM;
Viresh Kumard5b73cd2013-08-06 22:53:06 +0530187 driver = kzalloc(sizeof(*driver), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 if (!driver)
189 goto err_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
Viresh Kumard5b73cd2013-08-06 22:53:06 +0530191 us3_freq_table = kzalloc((NR_CPUS * sizeof(*us3_freq_table)),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 GFP_KERNEL);
193 if (!us3_freq_table)
194 goto err_out;
195
David S. Miller2cab2242005-08-18 14:35:38 -0700196 driver->init = us3_freq_cpu_init;
Viresh Kumar7a1874a2013-10-03 20:28:26 +0530197 driver->verify = cpufreq_generic_frequency_table_verify;
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530198 driver->target_index = us3_freq_target;
David S. Miller2cab2242005-08-18 14:35:38 -0700199 driver->get = us3_freq_get;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 driver->exit = us3_freq_cpu_exit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 strcpy(driver->name, "UltraSPARC-III");
202
203 cpufreq_us3_driver = driver;
204 ret = cpufreq_register_driver(driver);
205 if (ret)
206 goto err_out;
207
208 return 0;
209
210err_out:
211 if (driver) {
212 kfree(driver);
213 cpufreq_us3_driver = NULL;
214 }
Jesper Juhlb2325fe2005-11-07 01:01:35 -0800215 kfree(us3_freq_table);
216 us3_freq_table = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 return ret;
218 }
219
220 return -ENODEV;
221}
222
223static void __exit us3_freq_exit(void)
224{
225 if (cpufreq_us3_driver) {
226 cpufreq_unregister_driver(cpufreq_us3_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 kfree(cpufreq_us3_driver);
228 cpufreq_us3_driver = NULL;
229 kfree(us3_freq_table);
230 us3_freq_table = NULL;
231 }
232}
233
234MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
235MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III");
236MODULE_LICENSE("GPL");
237
238module_init(us3_freq_init);
239module_exit(us3_freq_exit);