2 * Copyright (c) 2006-2008 Simtec Electronics
3 * http://armlinux.simtec.co.uk/
4 * Ben Dooks <ben@simtec.co.uk>
6 * S3C24XX CPU Frequency scaling
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/interrupt.h>
18 #include <linux/ioport.h>
19 #include <linux/cpufreq.h>
20 #include <linux/cpu.h>
21 #include <linux/clk.h>
22 #include <linux/err.h>
24 #include <linux/device.h>
25 #include <linux/sysfs.h>
26 #include <linux/slab.h>
28 #include <asm/mach/arch.h>
29 #include <asm/mach/map.h>
32 #include <plat/cpu-freq-core.h>
34 #include <mach/regs-clock.h>
36 /* note, cpufreq support deals in kHz, no Hz */
38 static struct cpufreq_driver s3c24xx_driver
;
39 static struct s3c_cpufreq_config cpu_cur
;
40 static struct s3c_iotimings s3c24xx_iotiming
;
41 static struct cpufreq_frequency_table
*pll_reg
;
42 static unsigned int last_target
= ~0;
43 static unsigned int ftab_size
;
44 static struct cpufreq_frequency_table
*ftab
;
46 static struct clk
*_clk_mpll
;
47 static struct clk
*_clk_xtal
;
48 static struct clk
*clk_fclk
;
49 static struct clk
*clk_hclk
;
50 static struct clk
*clk_pclk
;
51 static struct clk
*clk_arm
;
53 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ_DEBUGFS
54 struct s3c_cpufreq_config
*s3c_cpufreq_getconfig(void)
59 struct s3c_iotimings
*s3c_cpufreq_getiotimings(void)
61 return &s3c24xx_iotiming
;
63 #endif /* CONFIG_ARM_S3C24XX_CPUFREQ_DEBUGFS */
65 static void s3c_cpufreq_getcur(struct s3c_cpufreq_config
*cfg
)
67 unsigned long fclk
, pclk
, hclk
, armclk
;
69 cfg
->freq
.fclk
= fclk
= clk_get_rate(clk_fclk
);
70 cfg
->freq
.hclk
= hclk
= clk_get_rate(clk_hclk
);
71 cfg
->freq
.pclk
= pclk
= clk_get_rate(clk_pclk
);
72 cfg
->freq
.armclk
= armclk
= clk_get_rate(clk_arm
);
74 cfg
->pll
.driver_data
= __raw_readl(S3C2410_MPLLCON
);
75 cfg
->pll
.frequency
= fclk
;
77 cfg
->freq
.hclk_tns
= 1000000000 / (cfg
->freq
.hclk
/ 10);
79 cfg
->divs
.h_divisor
= fclk
/ hclk
;
80 cfg
->divs
.p_divisor
= fclk
/ pclk
;
83 static inline void s3c_cpufreq_calc(struct s3c_cpufreq_config
*cfg
)
85 unsigned long pll
= cfg
->pll
.frequency
;
88 cfg
->freq
.hclk
= pll
/ cfg
->divs
.h_divisor
;
89 cfg
->freq
.pclk
= pll
/ cfg
->divs
.p_divisor
;
91 /* convert hclk into 10ths of nanoseconds for io calcs */
92 cfg
->freq
.hclk_tns
= 1000000000 / (cfg
->freq
.hclk
/ 10);
95 static inline int closer(unsigned int target
, unsigned int n
, unsigned int c
)
97 int diff_cur
= abs(target
- c
);
98 int diff_new
= abs(target
- n
);
100 return (diff_new
< diff_cur
);
103 static void s3c_cpufreq_show(const char *pfx
,
104 struct s3c_cpufreq_config
*cfg
)
106 s3c_freq_dbg("%s: Fvco=%u, F=%lu, A=%lu, H=%lu (%u), P=%lu (%u)\n",
107 pfx
, cfg
->pll
.frequency
, cfg
->freq
.fclk
, cfg
->freq
.armclk
,
108 cfg
->freq
.hclk
, cfg
->divs
.h_divisor
,
109 cfg
->freq
.pclk
, cfg
->divs
.p_divisor
);
112 /* functions to wrapper the driver info calls to do the cpu specific work */
114 static void s3c_cpufreq_setio(struct s3c_cpufreq_config
*cfg
)
116 if (cfg
->info
->set_iotiming
)
117 (cfg
->info
->set_iotiming
)(cfg
, &s3c24xx_iotiming
);
120 static int s3c_cpufreq_calcio(struct s3c_cpufreq_config
*cfg
)
122 if (cfg
->info
->calc_iotiming
)
123 return (cfg
->info
->calc_iotiming
)(cfg
, &s3c24xx_iotiming
);
128 static void s3c_cpufreq_setrefresh(struct s3c_cpufreq_config
*cfg
)
130 (cfg
->info
->set_refresh
)(cfg
);
133 static void s3c_cpufreq_setdivs(struct s3c_cpufreq_config
*cfg
)
135 (cfg
->info
->set_divs
)(cfg
);
138 static int s3c_cpufreq_calcdivs(struct s3c_cpufreq_config
*cfg
)
140 return (cfg
->info
->calc_divs
)(cfg
);
143 static void s3c_cpufreq_setfvco(struct s3c_cpufreq_config
*cfg
)
145 cfg
->mpll
= _clk_mpll
;
146 (cfg
->info
->set_fvco
)(cfg
);
149 static inline void s3c_cpufreq_updateclk(struct clk
*clk
,
152 clk_set_rate(clk
, freq
);
155 static int s3c_cpufreq_settarget(struct cpufreq_policy
*policy
,
156 unsigned int target_freq
,
157 struct cpufreq_frequency_table
*pll
)
159 struct s3c_cpufreq_freqs freqs
;
160 struct s3c_cpufreq_config cpu_new
;
163 cpu_new
= cpu_cur
; /* copy new from current */
165 s3c_cpufreq_show("cur", &cpu_cur
);
167 /* TODO - check for DMA currently outstanding */
169 cpu_new
.pll
= pll
? *pll
: cpu_cur
.pll
;
172 freqs
.pll_changing
= 1;
174 /* update our frequencies */
176 cpu_new
.freq
.armclk
= target_freq
;
177 cpu_new
.freq
.fclk
= cpu_new
.pll
.frequency
;
179 if (s3c_cpufreq_calcdivs(&cpu_new
) < 0) {
180 pr_err("no divisors for %d\n", target_freq
);
181 goto err_notpossible
;
184 s3c_freq_dbg("%s: got divs\n", __func__
);
186 s3c_cpufreq_calc(&cpu_new
);
188 s3c_freq_dbg("%s: calculated frequencies for new\n", __func__
);
190 if (cpu_new
.freq
.hclk
!= cpu_cur
.freq
.hclk
) {
191 if (s3c_cpufreq_calcio(&cpu_new
) < 0) {
192 pr_err("%s: no IO timings\n", __func__
);
193 goto err_notpossible
;
197 s3c_cpufreq_show("new", &cpu_new
);
199 /* setup our cpufreq parameters */
201 freqs
.old
= cpu_cur
.freq
;
202 freqs
.new = cpu_new
.freq
;
204 freqs
.freqs
.old
= cpu_cur
.freq
.armclk
/ 1000;
205 freqs
.freqs
.new = cpu_new
.freq
.armclk
/ 1000;
207 /* update f/h/p clock settings before we issue the change
208 * notification, so that drivers do not need to do anything
209 * special if they want to recalculate on CPUFREQ_PRECHANGE. */
211 s3c_cpufreq_updateclk(_clk_mpll
, cpu_new
.pll
.frequency
);
212 s3c_cpufreq_updateclk(clk_fclk
, cpu_new
.freq
.fclk
);
213 s3c_cpufreq_updateclk(clk_hclk
, cpu_new
.freq
.hclk
);
214 s3c_cpufreq_updateclk(clk_pclk
, cpu_new
.freq
.pclk
);
216 /* start the frequency change */
217 cpufreq_freq_transition_begin(policy
, &freqs
.freqs
);
219 /* If hclk is staying the same, then we do not need to
220 * re-write the IO or the refresh timings whilst we are changing
223 local_irq_save(flags
);
225 /* is our memory clock slowing down? */
226 if (cpu_new
.freq
.hclk
< cpu_cur
.freq
.hclk
) {
227 s3c_cpufreq_setrefresh(&cpu_new
);
228 s3c_cpufreq_setio(&cpu_new
);
231 if (cpu_new
.freq
.fclk
== cpu_cur
.freq
.fclk
) {
232 /* not changing PLL, just set the divisors */
234 s3c_cpufreq_setdivs(&cpu_new
);
236 if (cpu_new
.freq
.fclk
< cpu_cur
.freq
.fclk
) {
237 /* slow the cpu down, then set divisors */
239 s3c_cpufreq_setfvco(&cpu_new
);
240 s3c_cpufreq_setdivs(&cpu_new
);
242 /* set the divisors, then speed up */
244 s3c_cpufreq_setdivs(&cpu_new
);
245 s3c_cpufreq_setfvco(&cpu_new
);
249 /* did our memory clock speed up */
250 if (cpu_new
.freq
.hclk
> cpu_cur
.freq
.hclk
) {
251 s3c_cpufreq_setrefresh(&cpu_new
);
252 s3c_cpufreq_setio(&cpu_new
);
255 /* update our current settings */
258 local_irq_restore(flags
);
260 /* notify everyone we've done this */
261 cpufreq_freq_transition_end(policy
, &freqs
.freqs
, 0);
263 s3c_freq_dbg("%s: finished\n", __func__
);
267 pr_err("no compatible settings for %d\n", target_freq
);
271 /* s3c_cpufreq_target
273 * called by the cpufreq core to adjust the frequency that the CPU
274 * is currently running at.
277 static int s3c_cpufreq_target(struct cpufreq_policy
*policy
,
278 unsigned int target_freq
,
279 unsigned int relation
)
281 struct cpufreq_frequency_table
*pll
;
284 /* avoid repeated calls which cause a needless amout of duplicated
285 * logging output (and CPU time as the calculation process is
287 if (target_freq
== last_target
)
290 last_target
= target_freq
;
292 s3c_freq_dbg("%s: policy %p, target %u, relation %u\n",
293 __func__
, policy
, target_freq
, relation
);
296 index
= cpufreq_frequency_table_target(policy
, target_freq
,
299 s3c_freq_dbg("%s: adjust %d to entry %d (%u)\n", __func__
,
300 target_freq
, index
, ftab
[index
].frequency
);
301 target_freq
= ftab
[index
].frequency
;
304 target_freq
*= 1000; /* convert target to Hz */
306 /* find the settings for our new frequency */
308 if (!pll_reg
|| cpu_cur
.lock_pll
) {
309 /* either we've not got any PLL values, or we've locked
310 * to the current one. */
313 struct cpufreq_policy tmp_policy
;
315 /* we keep the cpu pll table in Hz, to ensure we get an
316 * accurate value for the PLL output. */
318 tmp_policy
.min
= policy
->min
* 1000;
319 tmp_policy
.max
= policy
->max
* 1000;
320 tmp_policy
.cpu
= policy
->cpu
;
321 tmp_policy
.freq_table
= pll_reg
;
323 /* cpufreq_frequency_table_target returns the index
324 * of the table entry, not the value of
325 * the table entry's index field. */
327 index
= cpufreq_frequency_table_target(&tmp_policy
, target_freq
,
329 pll
= pll_reg
+ index
;
331 s3c_freq_dbg("%s: target %u => %u\n",
332 __func__
, target_freq
, pll
->frequency
);
334 target_freq
= pll
->frequency
;
337 return s3c_cpufreq_settarget(policy
, target_freq
, pll
);
340 struct clk
*s3c_cpufreq_clk_get(struct device
*dev
, const char *name
)
344 clk
= clk_get(dev
, name
);
346 pr_err("failed to get clock '%s'\n", name
);
351 static int s3c_cpufreq_init(struct cpufreq_policy
*policy
)
353 policy
->clk
= clk_arm
;
354 return cpufreq_generic_init(policy
, ftab
, cpu_cur
.info
->latency
);
357 static int __init
s3c_cpufreq_initclks(void)
359 _clk_mpll
= s3c_cpufreq_clk_get(NULL
, "mpll");
360 _clk_xtal
= s3c_cpufreq_clk_get(NULL
, "xtal");
361 clk_fclk
= s3c_cpufreq_clk_get(NULL
, "fclk");
362 clk_hclk
= s3c_cpufreq_clk_get(NULL
, "hclk");
363 clk_pclk
= s3c_cpufreq_clk_get(NULL
, "pclk");
364 clk_arm
= s3c_cpufreq_clk_get(NULL
, "armclk");
366 if (IS_ERR(clk_fclk
) || IS_ERR(clk_hclk
) || IS_ERR(clk_pclk
) ||
367 IS_ERR(_clk_mpll
) || IS_ERR(clk_arm
) || IS_ERR(_clk_xtal
)) {
368 pr_err("%s: could not get clock(s)\n", __func__
);
372 pr_info("%s: clocks f=%lu,h=%lu,p=%lu,a=%lu\n",
374 clk_get_rate(clk_fclk
) / 1000,
375 clk_get_rate(clk_hclk
) / 1000,
376 clk_get_rate(clk_pclk
) / 1000,
377 clk_get_rate(clk_arm
) / 1000);
383 static struct cpufreq_frequency_table suspend_pll
;
384 static unsigned int suspend_freq
;
386 static int s3c_cpufreq_suspend(struct cpufreq_policy
*policy
)
388 suspend_pll
.frequency
= clk_get_rate(_clk_mpll
);
389 suspend_pll
.driver_data
= __raw_readl(S3C2410_MPLLCON
);
390 suspend_freq
= clk_get_rate(clk_arm
);
395 static int s3c_cpufreq_resume(struct cpufreq_policy
*policy
)
399 s3c_freq_dbg("%s: resuming with policy %p\n", __func__
, policy
);
401 last_target
= ~0; /* invalidate last_target setting */
403 /* whilst we will be called later on, we try and re-set the
404 * cpu frequencies as soon as possible so that we do not end
405 * up resuming devices and then immediately having to re-set
406 * a number of settings once these devices have restarted.
408 * as a note, it is expected devices are not used until they
409 * have been un-suspended and at that time they should have
410 * used the updated clock settings.
413 ret
= s3c_cpufreq_settarget(NULL
, suspend_freq
, &suspend_pll
);
415 pr_err("%s: failed to reset pll/freq\n", __func__
);
422 #define s3c_cpufreq_resume NULL
423 #define s3c_cpufreq_suspend NULL
426 static struct cpufreq_driver s3c24xx_driver
= {
427 .flags
= CPUFREQ_STICKY
| CPUFREQ_NEED_INITIAL_FREQ_CHECK
,
428 .target
= s3c_cpufreq_target
,
429 .get
= cpufreq_generic_get
,
430 .init
= s3c_cpufreq_init
,
431 .suspend
= s3c_cpufreq_suspend
,
432 .resume
= s3c_cpufreq_resume
,
437 int s3c_cpufreq_register(struct s3c_cpufreq_info
*info
)
439 if (!info
|| !info
->name
) {
440 pr_err("%s: failed to pass valid information\n", __func__
);
444 pr_info("S3C24XX CPU Frequency driver, %s cpu support\n",
447 /* check our driver info has valid data */
449 BUG_ON(info
->set_refresh
== NULL
);
450 BUG_ON(info
->set_divs
== NULL
);
451 BUG_ON(info
->calc_divs
== NULL
);
453 /* info->set_fvco is optional, depending on whether there
454 * is a need to set the clock code. */
458 /* Note, driver registering should probably update locktime */
463 int __init
s3c_cpufreq_setboard(struct s3c_cpufreq_board
*board
)
465 struct s3c_cpufreq_board
*ours
;
468 pr_info("%s: no board data\n", __func__
);
472 /* Copy the board information so that each board can make this
475 ours
= kzalloc(sizeof(*ours
), GFP_KERNEL
);
477 pr_err("%s: no memory\n", __func__
);
482 cpu_cur
.board
= ours
;
487 static int __init
s3c_cpufreq_auto_io(void)
491 if (!cpu_cur
.info
->get_iotiming
) {
492 pr_err("%s: get_iotiming undefined\n", __func__
);
496 pr_info("%s: working out IO settings\n", __func__
);
498 ret
= (cpu_cur
.info
->get_iotiming
)(&cpu_cur
, &s3c24xx_iotiming
);
500 pr_err("%s: failed to get timings\n", __func__
);
505 /* if one or is zero, then return the other, otherwise return the min */
506 #define do_min(_a, _b) ((_a) == 0 ? (_b) : (_b) == 0 ? (_a) : min(_a, _b))
509 * s3c_cpufreq_freq_min - find the minimum settings for the given freq.
510 * @dst: The destination structure
512 * @b: The other argument.
514 * Create a minimum of each frequency entry in the 'struct s3c_freq',
515 * unless the entry is zero when it is ignored and the non-zero argument
518 static void s3c_cpufreq_freq_min(struct s3c_freq
*dst
,
519 struct s3c_freq
*a
, struct s3c_freq
*b
)
521 dst
->fclk
= do_min(a
->fclk
, b
->fclk
);
522 dst
->hclk
= do_min(a
->hclk
, b
->hclk
);
523 dst
->pclk
= do_min(a
->pclk
, b
->pclk
);
524 dst
->armclk
= do_min(a
->armclk
, b
->armclk
);
527 static inline u32
calc_locktime(u32 freq
, u32 time_us
)
531 result
= freq
* time_us
;
532 result
= DIV_ROUND_UP(result
, 1000 * 1000);
537 static void s3c_cpufreq_update_loctkime(void)
539 unsigned int bits
= cpu_cur
.info
->locktime_bits
;
540 u32 rate
= (u32
)clk_get_rate(_clk_xtal
);
548 val
= calc_locktime(rate
, cpu_cur
.info
->locktime_u
) << bits
;
549 val
|= calc_locktime(rate
, cpu_cur
.info
->locktime_m
);
551 pr_info("%s: new locktime is 0x%08x\n", __func__
, val
);
552 __raw_writel(val
, S3C2410_LOCKTIME
);
555 static int s3c_cpufreq_build_freq(void)
561 size
= cpu_cur
.info
->calc_freqtable(&cpu_cur
, NULL
, 0);
564 ftab
= kzalloc(sizeof(*ftab
) * size
, GFP_KERNEL
);
566 pr_err("%s: no memory for tables\n", __func__
);
572 ret
= cpu_cur
.info
->calc_freqtable(&cpu_cur
, ftab
, size
);
573 s3c_cpufreq_addfreq(ftab
, ret
, size
, CPUFREQ_TABLE_END
);
578 static int __init
s3c_cpufreq_initcall(void)
582 if (cpu_cur
.info
&& cpu_cur
.board
) {
583 ret
= s3c_cpufreq_initclks();
587 /* get current settings */
588 s3c_cpufreq_getcur(&cpu_cur
);
589 s3c_cpufreq_show("cur", &cpu_cur
);
591 if (cpu_cur
.board
->auto_io
) {
592 ret
= s3c_cpufreq_auto_io();
594 pr_err("%s: failed to get io timing\n",
600 if (cpu_cur
.board
->need_io
&& !cpu_cur
.info
->set_iotiming
) {
601 pr_err("%s: no IO support registered\n", __func__
);
606 if (!cpu_cur
.info
->need_pll
)
607 cpu_cur
.lock_pll
= 1;
609 s3c_cpufreq_update_loctkime();
611 s3c_cpufreq_freq_min(&cpu_cur
.max
, &cpu_cur
.board
->max
,
614 if (cpu_cur
.info
->calc_freqtable
)
615 s3c_cpufreq_build_freq();
617 ret
= cpufreq_register_driver(&s3c24xx_driver
);
624 late_initcall(s3c_cpufreq_initcall
);
627 * s3c_plltab_register - register CPU PLL table.
628 * @plls: The list of PLL entries.
629 * @plls_no: The size of the PLL entries @plls.
631 * Register the given set of PLLs with the system.
633 int s3c_plltab_register(struct cpufreq_frequency_table
*plls
,
634 unsigned int plls_no
)
636 struct cpufreq_frequency_table
*vals
;
639 size
= sizeof(*vals
) * (plls_no
+ 1);
641 vals
= kzalloc(size
, GFP_KERNEL
);
643 memcpy(vals
, plls
, size
);
646 /* write a terminating entry, we don't store it in the
647 * table that is stored in the kernel */
649 vals
->frequency
= CPUFREQ_TABLE_END
;
651 pr_info("%d PLL entries\n", plls_no
);
653 pr_err("no memory for PLL tables\n");
655 return vals
? 0 : -ENOMEM
;