2 * linux/arch/arm/mach-pxa/cpufreq-pxa2xx.c
4 * Copyright (C) 2002,2003 Intrinsyc Software
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 * 31-Jul-2002 : Initial version [FB]
22 * 29-Jan-2003 : added PXA255 support [FB]
23 * 20-Apr-2003 : ported to v2.5 (Dustin McIntire, Sensoria Corp.)
26 * This driver may change the memory bus clock rate, but will not do any
27 * platform specific access timing changes... for example if you have flash
28 * memory connected to CS0, you will need to register a platform specific
29 * notifier which will adjust the memory access strobes to maintain a
30 * minimum strobe width.
34 #include <linux/kernel.h>
35 #include <linux/module.h>
36 #include <linux/sched.h>
37 #include <linux/init.h>
38 #include <linux/cpufreq.h>
39 #include <linux/err.h>
40 #include <linux/regulator/consumer.h>
42 #include <mach/pxa2xx-regs.h>
45 static unsigned int freq_debug
;
46 module_param(freq_debug
, uint
, 0);
47 MODULE_PARM_DESC(freq_debug
, "Set the debug messages to on=1/off=0");
52 static struct regulator
*vcc_core
;
54 static unsigned int pxa27x_maxfreq
;
55 module_param(pxa27x_maxfreq
, uint
, 0);
56 MODULE_PARM_DESC(pxa27x_maxfreq
, "Set the pxa27x maxfreq in MHz"
57 "(typically 624=>pxa270, 416=>pxa271, 520=>pxa272)");
69 /* Define the refresh period in mSec for the SDRAM and the number of rows */
70 #define SDRAM_TREF 64 /* standard 64ms SDRAM */
71 static unsigned int sdram_rows
;
73 #define CCLKCFG_TURBO 0x1
74 #define CCLKCFG_FCS 0x2
75 #define CCLKCFG_HALFTURBO 0x4
76 #define CCLKCFG_FASTBUS 0x8
77 #define MDREFR_DB2_MASK (MDREFR_K2DB2 | MDREFR_K1DB2)
78 #define MDREFR_DRI_MASK 0xFFF
80 #define MDCNFG_DRAC2(mdcnfg) (((mdcnfg) >> 21) & 0x3)
81 #define MDCNFG_DRAC0(mdcnfg) (((mdcnfg) >> 5) & 0x3)
86 /* Use the run mode frequencies for the CPUFREQ_POLICY_PERFORMANCE policy */
87 #define CCLKCFG CCLKCFG_TURBO | CCLKCFG_FCS
89 static pxa_freqs_t pxa255_run_freqs
[] =
91 /* CPU MEMBUS CCCR DIV2 CCLKCFG run turbo PXbus SDRAM */
92 { 99500, 99500, 0x121, 1, CCLKCFG
, -1, -1}, /* 99, 99, 50, 50 */
93 {132700, 132700, 0x123, 1, CCLKCFG
, -1, -1}, /* 133, 133, 66, 66 */
94 {199100, 99500, 0x141, 0, CCLKCFG
, -1, -1}, /* 199, 199, 99, 99 */
95 {265400, 132700, 0x143, 1, CCLKCFG
, -1, -1}, /* 265, 265, 133, 66 */
96 {331800, 165900, 0x145, 1, CCLKCFG
, -1, -1}, /* 331, 331, 166, 83 */
97 {398100, 99500, 0x161, 0, CCLKCFG
, -1, -1}, /* 398, 398, 196, 99 */
100 /* Use the turbo mode frequencies for the CPUFREQ_POLICY_POWERSAVE policy */
101 static pxa_freqs_t pxa255_turbo_freqs
[] =
103 /* CPU MEMBUS CCCR DIV2 CCLKCFG run turbo PXbus SDRAM */
104 { 99500, 99500, 0x121, 1, CCLKCFG
, -1, -1}, /* 99, 99, 50, 50 */
105 {199100, 99500, 0x221, 0, CCLKCFG
, -1, -1}, /* 99, 199, 50, 99 */
106 {298500, 99500, 0x321, 0, CCLKCFG
, -1, -1}, /* 99, 287, 50, 99 */
107 {298600, 99500, 0x1c1, 0, CCLKCFG
, -1, -1}, /* 199, 287, 99, 99 */
108 {398100, 99500, 0x241, 0, CCLKCFG
, -1, -1}, /* 199, 398, 99, 99 */
111 #define NUM_PXA25x_RUN_FREQS ARRAY_SIZE(pxa255_run_freqs)
112 #define NUM_PXA25x_TURBO_FREQS ARRAY_SIZE(pxa255_turbo_freqs)
114 static struct cpufreq_frequency_table
115 pxa255_run_freq_table
[NUM_PXA25x_RUN_FREQS
+1];
116 static struct cpufreq_frequency_table
117 pxa255_turbo_freq_table
[NUM_PXA25x_TURBO_FREQS
+1];
119 static unsigned int pxa255_turbo_table
;
120 module_param(pxa255_turbo_table
, uint
, 0);
121 MODULE_PARM_DESC(pxa255_turbo_table
, "Selects the frequency table (0 = run table, !0 = turbo table)");
127 * Control variables are A, L, 2N for CCCR; B, HT, T for CLKCFG.
129 * A = 0 => memory controller clock from table 3-7,
130 * A = 1 => memory controller clock = system bus clock
131 * Run mode frequency = 13 MHz * L
132 * Turbo mode frequency = 13 MHz * L * N
133 * System bus frequency = 13 MHz * L / (B + 1)
137 * L = 16 oscillator to run mode ratio
138 * 2N = 6 2 * (turbo mode to run mode ratio)
141 * B = 1 Fast bus mode
142 * HT = 0 Half-Turbo mode
145 * For now, just support some of the combinations in table 3-7 of
146 * PXA27x Processor Family Developer's Manual to simplify frequency
149 #define PXA27x_CCCR(A, L, N2) (A << 25 | N2 << 7 | L)
150 #define CCLKCFG2(B, HT, T) \
152 ((B) ? CCLKCFG_FASTBUS : 0) | \
153 ((HT) ? CCLKCFG_HALFTURBO : 0) | \
154 ((T) ? CCLKCFG_TURBO : 0))
156 static pxa_freqs_t pxa27x_freqs
[] = {
157 {104000, 104000, PXA27x_CCCR(1, 8, 2), 0, CCLKCFG2(1, 0, 1), 900000, 1705000 },
158 {156000, 104000, PXA27x_CCCR(1, 8, 6), 0, CCLKCFG2(1, 1, 1), 1000000, 1705000 },
159 {208000, 208000, PXA27x_CCCR(0, 16, 2), 1, CCLKCFG2(0, 0, 1), 1180000, 1705000 },
160 {312000, 208000, PXA27x_CCCR(1, 16, 3), 1, CCLKCFG2(1, 0, 1), 1250000, 1705000 },
161 {416000, 208000, PXA27x_CCCR(1, 16, 4), 1, CCLKCFG2(1, 0, 1), 1350000, 1705000 },
162 {520000, 208000, PXA27x_CCCR(1, 16, 5), 1, CCLKCFG2(1, 0, 1), 1450000, 1705000 },
163 {624000, 208000, PXA27x_CCCR(1, 16, 6), 1, CCLKCFG2(1, 0, 1), 1550000, 1705000 }
166 #define NUM_PXA27x_FREQS ARRAY_SIZE(pxa27x_freqs)
167 static struct cpufreq_frequency_table
168 pxa27x_freq_table
[NUM_PXA27x_FREQS
+1];
170 extern unsigned get_clk_frequency_khz(int info
);
172 #ifdef CONFIG_REGULATOR
174 static int pxa_cpufreq_change_voltage(pxa_freqs_t
*pxa_freq
)
179 if (!cpu_is_pxa27x())
182 vmin
= pxa_freq
->vmin
;
183 vmax
= pxa_freq
->vmax
;
184 if ((vmin
== -1) || (vmax
== -1))
187 ret
= regulator_set_voltage(vcc_core
, vmin
, vmax
);
189 pr_err("cpufreq: Failed to set vcc_core in [%dmV..%dmV]\n",
194 static __init
void pxa_cpufreq_init_voltages(void)
196 vcc_core
= regulator_get(NULL
, "vcc_core");
197 if (IS_ERR(vcc_core
)) {
198 pr_info("cpufreq: Didn't find vcc_core regulator\n");
201 pr_info("cpufreq: Found vcc_core regulator\n");
205 static int pxa_cpufreq_change_voltage(pxa_freqs_t
*pxa_freq
)
210 static __init
void pxa_cpufreq_init_voltages(void) { }
213 static void find_freq_tables(struct cpufreq_frequency_table
**freq_table
,
214 pxa_freqs_t
**pxa_freqs
)
216 if (cpu_is_pxa25x()) {
217 if (!pxa255_turbo_table
) {
218 *pxa_freqs
= pxa255_run_freqs
;
219 *freq_table
= pxa255_run_freq_table
;
221 *pxa_freqs
= pxa255_turbo_freqs
;
222 *freq_table
= pxa255_turbo_freq_table
;
225 if (cpu_is_pxa27x()) {
226 *pxa_freqs
= pxa27x_freqs
;
227 *freq_table
= pxa27x_freq_table
;
231 static void pxa27x_guess_max_freq(void)
233 if (!pxa27x_maxfreq
) {
234 pxa27x_maxfreq
= 416000;
235 printk(KERN_INFO
"PXA CPU 27x max frequency not defined "
236 "(pxa27x_maxfreq), assuming pxa271 with %dkHz maxfreq\n",
239 pxa27x_maxfreq
*= 1000;
243 static void init_sdram_rows(void)
245 uint32_t mdcnfg
= MDCNFG
;
246 unsigned int drac2
= 0, drac0
= 0;
248 if (mdcnfg
& (MDCNFG_DE2
| MDCNFG_DE3
))
249 drac2
= MDCNFG_DRAC2(mdcnfg
);
251 if (mdcnfg
& (MDCNFG_DE0
| MDCNFG_DE1
))
252 drac0
= MDCNFG_DRAC0(mdcnfg
);
254 sdram_rows
= 1 << (11 + max(drac0
, drac2
));
257 static u32
mdrefr_dri(unsigned int freq
)
262 dri
= ((freq
* SDRAM_TREF
) / (sdram_rows
* 32));
264 dri
= ((freq
* SDRAM_TREF
) / (sdram_rows
- 31)) / 32;
268 /* find a valid frequency point */
269 static int pxa_verify_policy(struct cpufreq_policy
*policy
)
271 struct cpufreq_frequency_table
*pxa_freqs_table
;
272 pxa_freqs_t
*pxa_freqs
;
275 find_freq_tables(&pxa_freqs_table
, &pxa_freqs
);
276 ret
= cpufreq_frequency_table_verify(policy
, pxa_freqs_table
);
279 pr_debug("Verified CPU policy: %dKhz min to %dKhz max\n",
280 policy
->min
, policy
->max
);
285 static unsigned int pxa_cpufreq_get(unsigned int cpu
)
287 return get_clk_frequency_khz(0);
290 static int pxa_set_target(struct cpufreq_policy
*policy
,
291 unsigned int target_freq
,
292 unsigned int relation
)
294 struct cpufreq_frequency_table
*pxa_freqs_table
;
295 pxa_freqs_t
*pxa_freq_settings
;
296 struct cpufreq_freqs freqs
;
299 unsigned int new_freq_cpu
, new_freq_mem
;
300 unsigned int unused
, preset_mdrefr
, postset_mdrefr
, cclkcfg
;
303 /* Get the current policy */
304 find_freq_tables(&pxa_freqs_table
, &pxa_freq_settings
);
306 /* Lookup the next frequency */
307 if (cpufreq_frequency_table_target(policy
, pxa_freqs_table
,
308 target_freq
, relation
, &idx
)) {
312 new_freq_cpu
= pxa_freq_settings
[idx
].khz
;
313 new_freq_mem
= pxa_freq_settings
[idx
].membus
;
314 freqs
.old
= policy
->cur
;
315 freqs
.new = new_freq_cpu
;
316 freqs
.cpu
= policy
->cpu
;
319 pr_debug(KERN_INFO
"Changing CPU frequency to %d Mhz, "
321 freqs
.new / 1000, (pxa_freq_settings
[idx
].div2
) ?
322 (new_freq_mem
/ 2000) : (new_freq_mem
/ 1000));
324 if (vcc_core
&& freqs
.new > freqs
.old
)
325 ret
= pxa_cpufreq_change_voltage(&pxa_freq_settings
[idx
]);
329 * Tell everyone what we're about to do...
330 * you should add a notify client with any platform specific
331 * Vcc changing capability
333 cpufreq_notify_transition(&freqs
, CPUFREQ_PRECHANGE
);
335 /* Calculate the next MDREFR. If we're slowing down the SDRAM clock
336 * we need to preset the smaller DRI before the change. If we're
337 * speeding up we need to set the larger DRI value after the change.
339 preset_mdrefr
= postset_mdrefr
= MDREFR
;
340 if ((MDREFR
& MDREFR_DRI_MASK
) > mdrefr_dri(new_freq_mem
)) {
341 preset_mdrefr
= (preset_mdrefr
& ~MDREFR_DRI_MASK
);
342 preset_mdrefr
|= mdrefr_dri(new_freq_mem
);
345 (postset_mdrefr
& ~MDREFR_DRI_MASK
) | mdrefr_dri(new_freq_mem
);
347 /* If we're dividing the memory clock by two for the SDRAM clock, this
348 * must be set prior to the change. Clearing the divide must be done
351 if (pxa_freq_settings
[idx
].div2
) {
352 preset_mdrefr
|= MDREFR_DB2_MASK
;
353 postset_mdrefr
|= MDREFR_DB2_MASK
;
355 postset_mdrefr
&= ~MDREFR_DB2_MASK
;
358 local_irq_save(flags
);
360 /* Set new the CCCR and prepare CCLKCFG */
361 CCCR
= pxa_freq_settings
[idx
].cccr
;
362 cclkcfg
= pxa_freq_settings
[idx
].cclkcfg
;
365 ldr r4, [%1] /* load MDREFR */ \n\
369 str %3, [%1] /* preset the MDREFR */ \n\
370 mcr p14, 0, %2, c6, c0, 0 /* set CCLKCFG[FCS] */ \n\
371 str %4, [%1] /* postset the MDREFR */ \n\
378 : "r" (&MDREFR
), "r" (cclkcfg
),
379 "r" (preset_mdrefr
), "r" (postset_mdrefr
)
381 local_irq_restore(flags
);
384 * Tell everyone what we've just done...
385 * you should add a notify client with any platform specific
386 * SDRAM refresh timer adjustments
388 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
391 * Even if voltage setting fails, we don't report it, as the frequency
392 * change succeeded. The voltage reduction is not a critical failure,
393 * only power savings will suffer from this.
395 * Note: if the voltage change fails, and a return value is returned, a
396 * bug is triggered (seems a deadlock). Should anybody find out where,
397 * the "return 0" should become a "return ret".
399 if (vcc_core
&& freqs
.new < freqs
.old
)
400 ret
= pxa_cpufreq_change_voltage(&pxa_freq_settings
[idx
]);
405 static __init
int pxa_cpufreq_init(struct cpufreq_policy
*policy
)
409 struct cpufreq_frequency_table
*pxa255_freq_table
;
410 pxa_freqs_t
*pxa255_freqs
;
412 /* try to guess pxa27x cpu */
414 pxa27x_guess_max_freq();
416 pxa_cpufreq_init_voltages();
420 /* set default policy and cpuinfo */
421 policy
->cpuinfo
.transition_latency
= 1000; /* FIXME: 1 ms, assumed */
422 policy
->cur
= get_clk_frequency_khz(0); /* current freq */
423 policy
->min
= policy
->max
= policy
->cur
;
425 /* Generate pxa25x the run cpufreq_frequency_table struct */
426 for (i
= 0; i
< NUM_PXA25x_RUN_FREQS
; i
++) {
427 pxa255_run_freq_table
[i
].frequency
= pxa255_run_freqs
[i
].khz
;
428 pxa255_run_freq_table
[i
].index
= i
;
430 pxa255_run_freq_table
[i
].frequency
= CPUFREQ_TABLE_END
;
432 /* Generate pxa25x the turbo cpufreq_frequency_table struct */
433 for (i
= 0; i
< NUM_PXA25x_TURBO_FREQS
; i
++) {
434 pxa255_turbo_freq_table
[i
].frequency
=
435 pxa255_turbo_freqs
[i
].khz
;
436 pxa255_turbo_freq_table
[i
].index
= i
;
438 pxa255_turbo_freq_table
[i
].frequency
= CPUFREQ_TABLE_END
;
440 pxa255_turbo_table
= !!pxa255_turbo_table
;
442 /* Generate the pxa27x cpufreq_frequency_table struct */
443 for (i
= 0; i
< NUM_PXA27x_FREQS
; i
++) {
444 freq
= pxa27x_freqs
[i
].khz
;
445 if (freq
> pxa27x_maxfreq
)
447 pxa27x_freq_table
[i
].frequency
= freq
;
448 pxa27x_freq_table
[i
].index
= i
;
450 pxa27x_freq_table
[i
].frequency
= CPUFREQ_TABLE_END
;
453 * Set the policy's minimum and maximum frequencies from the tables
454 * just constructed. This sets cpuinfo.mxx_freq, min and max.
456 if (cpu_is_pxa25x()) {
457 find_freq_tables(&pxa255_freq_table
, &pxa255_freqs
);
458 pr_info("PXA255 cpufreq using %s frequency table\n",
459 pxa255_turbo_table
? "turbo" : "run");
460 cpufreq_frequency_table_cpuinfo(policy
, pxa255_freq_table
);
462 else if (cpu_is_pxa27x())
463 cpufreq_frequency_table_cpuinfo(policy
, pxa27x_freq_table
);
465 printk(KERN_INFO
"PXA CPU frequency change support initialized\n");
470 static struct cpufreq_driver pxa_cpufreq_driver
= {
471 .verify
= pxa_verify_policy
,
472 .target
= pxa_set_target
,
473 .init
= pxa_cpufreq_init
,
474 .get
= pxa_cpufreq_get
,
478 static int __init
pxa_cpu_init(void)
481 if (cpu_is_pxa25x() || cpu_is_pxa27x())
482 ret
= cpufreq_register_driver(&pxa_cpufreq_driver
);
486 static void __exit
pxa_cpu_exit(void)
488 cpufreq_unregister_driver(&pxa_cpufreq_driver
);
492 MODULE_AUTHOR("Intrinsyc Software Inc.");
493 MODULE_DESCRIPTION("CPU frequency changing driver for the PXA architecture");
494 MODULE_LICENSE("GPL");
495 module_init(pxa_cpu_init
);
496 module_exit(pxa_cpu_exit
);