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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
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
35
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 :
65 : "r" (val), "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E)
66 : "memory");
67 if (addr == HBIRD_ESTAR_MODE_ADDR) {
68
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
107
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
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 cpumask_copy(&cpus_allowed, tsk_cpus_allowed(current));
238 set_cpus_allowed_ptr(current, cpumask_of(cpu));
239
240 clock_tick = sparc64_get_clock_tick(cpu) / 1000;
241 estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);
242
243 set_cpus_allowed_ptr(current, &cpus_allowed);
244
245 return clock_tick / estar_to_divisor(estar);
246}
247
248static int us2e_freq_target(struct cpufreq_policy *policy, unsigned int index)
249{
250 unsigned int cpu = policy->cpu;
251 unsigned long new_bits, new_freq;
252 unsigned long clock_tick, divisor, old_divisor, estar;
253 cpumask_t cpus_allowed;
254
255 cpumask_copy(&cpus_allowed, tsk_cpus_allowed(current));
256 set_cpus_allowed_ptr(current, cpumask_of(cpu));
257
258 new_freq = clock_tick = sparc64_get_clock_tick(cpu) / 1000;
259 new_bits = index_to_estar_mode(index);
260 divisor = index_to_divisor(index);
261 new_freq /= divisor;
262
263 estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);
264
265 old_divisor = estar_to_divisor(estar);
266
267 if (old_divisor != divisor)
268 us2e_transition(estar, new_bits, clock_tick * 1000,
269 old_divisor, divisor);
270
271 set_cpus_allowed_ptr(current, &cpus_allowed);
272
273 return 0;
274}
275
276static int __init us2e_freq_cpu_init(struct cpufreq_policy *policy)
277{
278 unsigned int cpu = policy->cpu;
279 unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
280 struct cpufreq_frequency_table *table =
281 &us2e_freq_table[cpu].table[0];
282
283 table[0].driver_data = 0;
284 table[0].frequency = clock_tick / 1;
285 table[1].driver_data = 1;
286 table[1].frequency = clock_tick / 2;
287 table[2].driver_data = 2;
288 table[2].frequency = clock_tick / 4;
289 table[2].driver_data = 3;
290 table[2].frequency = clock_tick / 6;
291 table[2].driver_data = 4;
292 table[2].frequency = clock_tick / 8;
293 table[2].driver_data = 5;
294 table[3].frequency = CPUFREQ_TABLE_END;
295
296 policy->cpuinfo.transition_latency = 0;
297 policy->cur = clock_tick;
298
299 return cpufreq_table_validate_and_show(policy, table);
300}
301
302static int us2e_freq_cpu_exit(struct cpufreq_policy *policy)
303{
304 if (cpufreq_us2e_driver)
305 us2e_freq_target(policy, 0);
306
307 return 0;
308}
309
310static int __init us2e_freq_init(void)
311{
312 unsigned long manuf, impl, ver;
313 int ret;
314
315 if (tlb_type != spitfire)
316 return -ENODEV;
317
318 __asm__("rdpr %%ver, %0" : "=r" (ver));
319 manuf = ((ver >> 48) & 0xffff);
320 impl = ((ver >> 32) & 0xffff);
321
322 if (manuf == 0x17 && impl == 0x13) {
323 struct cpufreq_driver *driver;
324
325 ret = -ENOMEM;
326 driver = kzalloc(sizeof(*driver), GFP_KERNEL);
327 if (!driver)
328 goto err_out;
329
330 us2e_freq_table = kzalloc((NR_CPUS * sizeof(*us2e_freq_table)),
331 GFP_KERNEL);
332 if (!us2e_freq_table)
333 goto err_out;
334
335 driver->init = us2e_freq_cpu_init;
336 driver->verify = cpufreq_generic_frequency_table_verify;
337 driver->target_index = us2e_freq_target;
338 driver->get = us2e_freq_get;
339 driver->exit = us2e_freq_cpu_exit;
340 strcpy(driver->name, "UltraSPARC-IIe");
341
342 cpufreq_us2e_driver = driver;
343 ret = cpufreq_register_driver(driver);
344 if (ret)
345 goto err_out;
346
347 return 0;
348
349err_out:
350 if (driver) {
351 kfree(driver);
352 cpufreq_us2e_driver = NULL;
353 }
354 kfree(us2e_freq_table);
355 us2e_freq_table = NULL;
356 return ret;
357 }
358
359 return -ENODEV;
360}
361
362static void __exit us2e_freq_exit(void)
363{
364 if (cpufreq_us2e_driver) {
365 cpufreq_unregister_driver(cpufreq_us2e_driver);
366 kfree(cpufreq_us2e_driver);
367 cpufreq_us2e_driver = NULL;
368 kfree(us2e_freq_table);
369 us2e_freq_table = NULL;
370 }
371}
372
373MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
374MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-IIe");
375MODULE_LICENSE("GPL");
376
377module_init(us2e_freq_init);
378module_exit(us2e_freq_exit);
379
