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authorSam Ravnborg <sam@ravnborg.org>2008-12-03 06:11:52 -0500
committerDavid S. Miller <davem@davemloft.net>2008-12-04 12:17:21 -0500
commita88b5ba8bd8ac18aad65ee6c6a254e2e74876db3 (patch)
treeeb3d0ffaf53c3f7ec6083752c2097cecd1cb892a /arch/sparc/kernel/us2e_cpufreq.c
parentd670bd4f803c8b646acd20f3ba21e65458293faf (diff)
sparc,sparc64: unify kernel/
o Move all files from sparc64/kernel/ to sparc/kernel - rename as appropriate o Update sparc/Makefile to the changes o Update sparc/kernel/Makefile to include the sparc64 files NOTE: This commit changes link order on sparc64! Link order had to change for either of sparc32 and sparc64. And assuming sparc64 see more testing than sparc32 change link order on sparc64 where issues will be caught faster. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/kernel/us2e_cpufreq.c')
-rw-r--r--arch/sparc/kernel/us2e_cpufreq.c413
1 files changed, 413 insertions, 0 deletions
diff --git a/arch/sparc/kernel/us2e_cpufreq.c b/arch/sparc/kernel/us2e_cpufreq.c
new file mode 100644
index 000000000000..791c15138f3a
--- /dev/null
+++ b/arch/sparc/kernel/us2e_cpufreq.c
@@ -0,0 +1,413 @@
1/* us2e_cpufreq.c: UltraSPARC-IIe 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/delay.h>
17#include <linux/init.h>
18
19#include <asm/asi.h>
20#include <asm/timer.h>
21
22static struct cpufreq_driver *cpufreq_us2e_driver;
23
24struct us2e_freq_percpu_info {
25 struct cpufreq_frequency_table table[6];
26};
27
28/* Indexed by cpu number. */
29static struct us2e_freq_percpu_info *us2e_freq_table;
30
31#define HBIRD_MEM_CNTL0_ADDR 0x1fe0000f010UL
32#define HBIRD_ESTAR_MODE_ADDR 0x1fe0000f080UL
33
34/* UltraSPARC-IIe has five dividers: 1, 2, 4, 6, and 8. These are controlled
35 * in the ESTAR mode control register.
36 */
37#define ESTAR_MODE_DIV_1 0x0000000000000000UL
38#define ESTAR_MODE_DIV_2 0x0000000000000001UL
39#define ESTAR_MODE_DIV_4 0x0000000000000003UL
40#define ESTAR_MODE_DIV_6 0x0000000000000002UL
41#define ESTAR_MODE_DIV_8 0x0000000000000004UL
42#define ESTAR_MODE_DIV_MASK 0x0000000000000007UL
43
44#define MCTRL0_SREFRESH_ENAB 0x0000000000010000UL
45#define MCTRL0_REFR_COUNT_MASK 0x0000000000007f00UL
46#define MCTRL0_REFR_COUNT_SHIFT 8
47#define MCTRL0_REFR_INTERVAL 7800
48#define MCTRL0_REFR_CLKS_P_CNT 64
49
50static unsigned long read_hbreg(unsigned long addr)
51{
52 unsigned long ret;
53
54 __asm__ __volatile__("ldxa [%1] %2, %0"
55 : "=&r" (ret)
56 : "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E));
57 return ret;
58}
59
60static void write_hbreg(unsigned long addr, unsigned long val)
61{
62 __asm__ __volatile__("stxa %0, [%1] %2\n\t"
63 "membar #Sync"
64 : /* no outputs */
65 : "r" (val), "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E)
66 : "memory");
67 if (addr == HBIRD_ESTAR_MODE_ADDR) {
68 /* Need to wait 16 clock cycles for the PLL to lock. */
69 udelay(1);
70 }
71}
72
73static void self_refresh_ctl(int enable)
74{
75 unsigned long mctrl = read_hbreg(HBIRD_MEM_CNTL0_ADDR);
76
77 if (enable)
78 mctrl |= MCTRL0_SREFRESH_ENAB;
79 else
80 mctrl &= ~MCTRL0_SREFRESH_ENAB;
81 write_hbreg(HBIRD_MEM_CNTL0_ADDR, mctrl);
82 (void) read_hbreg(HBIRD_MEM_CNTL0_ADDR);
83}
84
85static void frob_mem_refresh(int cpu_slowing_down,
86 unsigned long clock_tick,
87 unsigned long old_divisor, unsigned long divisor)
88{
89 unsigned long old_refr_count, refr_count, mctrl;
90
91 refr_count = (clock_tick * MCTRL0_REFR_INTERVAL);
92 refr_count /= (MCTRL0_REFR_CLKS_P_CNT * divisor * 1000000000UL);
93
94 mctrl = read_hbreg(HBIRD_MEM_CNTL0_ADDR);
95 old_refr_count = (mctrl & MCTRL0_REFR_COUNT_MASK)
96 >> MCTRL0_REFR_COUNT_SHIFT;
97
98 mctrl &= ~MCTRL0_REFR_COUNT_MASK;
99 mctrl |= refr_count << MCTRL0_REFR_COUNT_SHIFT;
100 write_hbreg(HBIRD_MEM_CNTL0_ADDR, mctrl);
101 mctrl = read_hbreg(HBIRD_MEM_CNTL0_ADDR);
102
103 if (cpu_slowing_down && !(mctrl & MCTRL0_SREFRESH_ENAB)) {
104 unsigned long usecs;
105
106 /* We have to wait for both refresh counts (old
107 * and new) to go to zero.
108 */
109 usecs = (MCTRL0_REFR_CLKS_P_CNT *
110 (refr_count + old_refr_count) *
111 1000000UL *
112 old_divisor) / clock_tick;
113 udelay(usecs + 1UL);
114 }
115}
116
117static void us2e_transition(unsigned long estar, unsigned long new_bits,
118 unsigned long clock_tick,
119 unsigned long old_divisor, unsigned long divisor)
120{
121 unsigned long flags;
122
123 local_irq_save(flags);
124
125 estar &= ~ESTAR_MODE_DIV_MASK;
126
127 /* This is based upon the state transition diagram in the IIe manual. */
128 if (old_divisor == 2 && divisor == 1) {
129 self_refresh_ctl(0);
130 write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar | new_bits);
131 frob_mem_refresh(0, clock_tick, old_divisor, divisor);
132 } else if (old_divisor == 1 && divisor == 2) {
133 frob_mem_refresh(1, clock_tick, old_divisor, divisor);
134 write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar | new_bits);
135 self_refresh_ctl(1);
136 } else if (old_divisor == 1 && divisor > 2) {
137 us2e_transition(estar, ESTAR_MODE_DIV_2, clock_tick,
138 1, 2);
139 us2e_transition(estar, new_bits, clock_tick,
140 2, divisor);
141 } else if (old_divisor > 2 && divisor == 1) {
142 us2e_transition(estar, ESTAR_MODE_DIV_2, clock_tick,
143 old_divisor, 2);
144 us2e_transition(estar, new_bits, clock_tick,
145 2, divisor);
146 } else if (old_divisor < divisor) {
147 frob_mem_refresh(0, clock_tick, old_divisor, divisor);
148 write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar | new_bits);
149 } else if (old_divisor > divisor) {
150 write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar | new_bits);
151 frob_mem_refresh(1, clock_tick, old_divisor, divisor);
152 } else {
153 BUG();
154 }
155
156 local_irq_restore(flags);
157}
158
159static unsigned long index_to_estar_mode(unsigned int index)
160{
161 switch (index) {
162 case 0:
163 return ESTAR_MODE_DIV_1;
164
165 case 1:
166 return ESTAR_MODE_DIV_2;
167
168 case 2:
169 return ESTAR_MODE_DIV_4;
170
171 case 3:
172 return ESTAR_MODE_DIV_6;
173
174 case 4:
175 return ESTAR_MODE_DIV_8;
176
177 default:
178 BUG();
179 };
180}
181
182static unsigned long index_to_divisor(unsigned int index)
183{
184 switch (index) {
185 case 0:
186 return 1;
187
188 case 1:
189 return 2;
190
191 case 2:
192 return 4;
193
194 case 3:
195 return 6;
196
197 case 4:
198 return 8;
199
200 default:
201 BUG();
202 };
203}
204
205static unsigned long estar_to_divisor(unsigned long estar)
206{
207 unsigned long ret;
208
209 switch (estar & ESTAR_MODE_DIV_MASK) {
210 case ESTAR_MODE_DIV_1:
211 ret = 1;
212 break;
213 case ESTAR_MODE_DIV_2:
214 ret = 2;
215 break;
216 case ESTAR_MODE_DIV_4:
217 ret = 4;
218 break;
219 case ESTAR_MODE_DIV_6:
220 ret = 6;
221 break;
222 case ESTAR_MODE_DIV_8:
223 ret = 8;
224 break;
225 default:
226 BUG();
227 };
228
229 return ret;
230}
231
232static unsigned int us2e_freq_get(unsigned int cpu)
233{
234 cpumask_t cpus_allowed;
235 unsigned long clock_tick, estar;
236
237 if (!cpu_online(cpu))
238 return 0;
239
240 cpus_allowed = current->cpus_allowed;
241 set_cpus_allowed(current, cpumask_of_cpu(cpu));
242
243 clock_tick = sparc64_get_clock_tick(cpu) / 1000;
244 estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);
245
246 set_cpus_allowed(current, cpus_allowed);
247
248 return clock_tick / estar_to_divisor(estar);
249}
250
251static void us2e_set_cpu_divider_index(unsigned int cpu, unsigned int index)
252{
253 unsigned long new_bits, new_freq;
254 unsigned long clock_tick, divisor, old_divisor, estar;
255 cpumask_t cpus_allowed;
256 struct cpufreq_freqs freqs;
257
258 if (!cpu_online(cpu))
259 return;
260
261 cpus_allowed = current->cpus_allowed;
262 set_cpus_allowed(current, cpumask_of_cpu(cpu));
263
264 new_freq = clock_tick = sparc64_get_clock_tick(cpu) / 1000;
265 new_bits = index_to_estar_mode(index);
266 divisor = index_to_divisor(index);
267 new_freq /= divisor;
268
269 estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);
270
271 old_divisor = estar_to_divisor(estar);
272
273 freqs.old = clock_tick / old_divisor;
274 freqs.new = new_freq;
275 freqs.cpu = cpu;
276 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
277
278 if (old_divisor != divisor)
279 us2e_transition(estar, new_bits, clock_tick * 1000,
280 old_divisor, divisor);
281
282 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
283
284 set_cpus_allowed(current, cpus_allowed);
285}
286
287static int us2e_freq_target(struct cpufreq_policy *policy,
288 unsigned int target_freq,
289 unsigned int relation)
290{
291 unsigned int new_index = 0;
292
293 if (cpufreq_frequency_table_target(policy,
294 &us2e_freq_table[policy->cpu].table[0],
295 target_freq, relation, &new_index))
296 return -EINVAL;
297
298 us2e_set_cpu_divider_index(policy->cpu, new_index);
299
300 return 0;
301}
302
303static int us2e_freq_verify(struct cpufreq_policy *policy)
304{
305 return cpufreq_frequency_table_verify(policy,
306 &us2e_freq_table[policy->cpu].table[0]);
307}
308
309static int __init us2e_freq_cpu_init(struct cpufreq_policy *policy)
310{
311 unsigned int cpu = policy->cpu;
312 unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
313 struct cpufreq_frequency_table *table =
314 &us2e_freq_table[cpu].table[0];
315
316 table[0].index = 0;
317 table[0].frequency = clock_tick / 1;
318 table[1].index = 1;
319 table[1].frequency = clock_tick / 2;
320 table[2].index = 2;
321 table[2].frequency = clock_tick / 4;
322 table[2].index = 3;
323 table[2].frequency = clock_tick / 6;
324 table[2].index = 4;
325 table[2].frequency = clock_tick / 8;
326 table[2].index = 5;
327 table[3].frequency = CPUFREQ_TABLE_END;
328
329 policy->cpuinfo.transition_latency = 0;
330 policy->cur = clock_tick;
331
332 return cpufreq_frequency_table_cpuinfo(policy, table);
333}
334
335static int us2e_freq_cpu_exit(struct cpufreq_policy *policy)
336{
337 if (cpufreq_us2e_driver)
338 us2e_set_cpu_divider_index(policy->cpu, 0);
339
340 return 0;
341}
342
343static int __init us2e_freq_init(void)
344{
345 unsigned long manuf, impl, ver;
346 int ret;
347
348 if (tlb_type != spitfire)
349 return -ENODEV;
350
351 __asm__("rdpr %%ver, %0" : "=r" (ver));
352 manuf = ((ver >> 48) & 0xffff);
353 impl = ((ver >> 32) & 0xffff);
354
355 if (manuf == 0x17 && impl == 0x13) {
356 struct cpufreq_driver *driver;
357
358 ret = -ENOMEM;
359 driver = kzalloc(sizeof(struct cpufreq_driver), GFP_KERNEL);
360 if (!driver)
361 goto err_out;
362
363 us2e_freq_table = kzalloc(
364 (NR_CPUS * sizeof(struct us2e_freq_percpu_info)),
365 GFP_KERNEL);
366 if (!us2e_freq_table)
367 goto err_out;
368
369 driver->init = us2e_freq_cpu_init;
370 driver->verify = us2e_freq_verify;
371 driver->target = us2e_freq_target;
372 driver->get = us2e_freq_get;
373 driver->exit = us2e_freq_cpu_exit;
374 driver->owner = THIS_MODULE,
375 strcpy(driver->name, "UltraSPARC-IIe");
376
377 cpufreq_us2e_driver = driver;
378 ret = cpufreq_register_driver(driver);
379 if (ret)
380 goto err_out;
381
382 return 0;
383
384err_out:
385 if (driver) {
386 kfree(driver);
387 cpufreq_us2e_driver = NULL;
388 }
389 kfree(us2e_freq_table);
390 us2e_freq_table = NULL;
391 return ret;
392 }
393
394 return -ENODEV;
395}
396
397static void __exit us2e_freq_exit(void)
398{
399 if (cpufreq_us2e_driver) {
400 cpufreq_unregister_driver(cpufreq_us2e_driver);
401 kfree(cpufreq_us2e_driver);
402 cpufreq_us2e_driver = NULL;
403 kfree(us2e_freq_table);
404 us2e_freq_table = NULL;
405 }
406}
407
408MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
409MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-IIe");
410MODULE_LICENSE("GPL");
411
412module_init(us2e_freq_init);
413module_exit(us2e_freq_exit);