1 /*
2 * linux/arch/arm/mach-at91/clock.c
3 *
4 * Copyright (C) 2005 David Brownell
5 * Copyright (C) 2005 Ivan Kokshaysky
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/fs.h>
17 #include <linux/debugfs.h>
18 #include <linux/seq_file.h>
19 #include <linux/list.h>
20 #include <linux/errno.h>
21 #include <linux/err.h>
22 #include <linux/spinlock.h>
23 #include <linux/delay.h>
24 #include <linux/clk.h>
25 #include <linux/io.h>
26 #include <linux/of_address.h>
27
28 #include <mach/hardware.h>
29 #include <mach/at91_pmc.h>
30 #include <mach/cpu.h>
31
32 #include <asm/proc-fns.h>
33
34 #include "clock.h"
35 #include "generic.h"
36
37 void __iomem *at91_pmc_base;
38 EXPORT_SYMBOL_GPL(at91_pmc_base);
39
40 /*
41 * There's a lot more which can be done with clocks, including cpufreq
42 * integration, slow clock mode support (for system suspend), letting
43 * PLLB be used at other rates (on boards that don't need USB), etc.
44 */
45
46 #define clk_is_primary(x) ((x)->type & CLK_TYPE_PRIMARY)
47 #define clk_is_programmable(x) ((x)->type & CLK_TYPE_PROGRAMMABLE)
48 #define clk_is_peripheral(x) ((x)->type & CLK_TYPE_PERIPHERAL)
49 #define clk_is_sys(x) ((x)->type & CLK_TYPE_SYSTEM)
50
51
52 /*
53 * Chips have some kind of clocks : group them by functionality
54 */
55 #define cpu_has_utmi() ( cpu_is_at91sam9rl() \
56 || cpu_is_at91sam9g45() \
57 || cpu_is_at91sam9x5())
58
59 #define cpu_has_800M_plla() ( cpu_is_at91sam9g20() \
60 || cpu_is_at91sam9g45() \
61 || cpu_is_at91sam9x5())
62
63 #define cpu_has_300M_plla() (cpu_is_at91sam9g10())
64
65 #define cpu_has_pllb() (!(cpu_is_at91sam9rl() \
66 || cpu_is_at91sam9g45() \
67 || cpu_is_at91sam9x5()))
68
69 #define cpu_has_upll() (cpu_is_at91sam9g45() \
70 || cpu_is_at91sam9x5())
71
72 /* USB host HS & FS */
73 #define cpu_has_uhp() (!cpu_is_at91sam9rl())
74
75 /* USB device FS only */
76 #define cpu_has_udpfs() (!(cpu_is_at91sam9rl() \
77 || cpu_is_at91sam9g45() \
78 || cpu_is_at91sam9x5()))
79
80 #define cpu_has_plladiv2() (cpu_is_at91sam9g45() \
81 || cpu_is_at91sam9x5())
82
83 #define cpu_has_mdiv3() (cpu_is_at91sam9g45() \
84 || cpu_is_at91sam9x5())
85
86 #define cpu_has_alt_prescaler() (cpu_is_at91sam9x5())
87
88 static LIST_HEAD(clocks);
89 static DEFINE_SPINLOCK(clk_lock);
90
91 static u32 at91_pllb_usb_init;
92
93 /*
94 * Four primary clock sources: two crystal oscillators (32K, main), and
95 * two PLLs. PLLA usually runs the master clock; and PLLB must run at
96 * 48 MHz (unless no USB function clocks are needed). The main clock and
97 * both PLLs are turned off to run in "slow clock mode" (system suspend).
98 */
99 static struct clk clk32k = {
100 .name = "clk32k",
101 .rate_hz = AT91_SLOW_CLOCK,
102 .users = 1, /* always on */
103 .id = 0,
104 .type = CLK_TYPE_PRIMARY,
105 };
106 static struct clk main_clk = {
107 .name = "main",
108 .pmc_mask = AT91_PMC_MOSCS, /* in PMC_SR */
109 .id = 1,
110 .type = CLK_TYPE_PRIMARY,
111 };
112 static struct clk plla = {
113 .name = "plla",
114 .parent = &main_clk,
115 .pmc_mask = AT91_PMC_LOCKA, /* in PMC_SR */
116 .id = 2,
117 .type = CLK_TYPE_PRIMARY | CLK_TYPE_PLL,
118 };
119
pllb_mode(struct clk * clk,int is_on)120 static void pllb_mode(struct clk *clk, int is_on)
121 {
122 u32 value;
123
124 if (is_on) {
125 is_on = AT91_PMC_LOCKB;
126 value = at91_pllb_usb_init;
127 } else
128 value = 0;
129
130 // REVISIT: Add work-around for AT91RM9200 Errata #26 ?
131 at91_pmc_write(AT91_CKGR_PLLBR, value);
132
133 do {
134 cpu_relax();
135 } while ((at91_pmc_read(AT91_PMC_SR) & AT91_PMC_LOCKB) != is_on);
136 }
137
138 static struct clk pllb = {
139 .name = "pllb",
140 .parent = &main_clk,
141 .pmc_mask = AT91_PMC_LOCKB, /* in PMC_SR */
142 .mode = pllb_mode,
143 .id = 3,
144 .type = CLK_TYPE_PRIMARY | CLK_TYPE_PLL,
145 };
146
pmc_sys_mode(struct clk * clk,int is_on)147 static void pmc_sys_mode(struct clk *clk, int is_on)
148 {
149 if (is_on)
150 at91_pmc_write(AT91_PMC_SCER, clk->pmc_mask);
151 else
152 at91_pmc_write(AT91_PMC_SCDR, clk->pmc_mask);
153 }
154
pmc_uckr_mode(struct clk * clk,int is_on)155 static void pmc_uckr_mode(struct clk *clk, int is_on)
156 {
157 unsigned int uckr = at91_pmc_read(AT91_CKGR_UCKR);
158
159 if (is_on) {
160 is_on = AT91_PMC_LOCKU;
161 at91_pmc_write(AT91_CKGR_UCKR, uckr | clk->pmc_mask);
162 } else
163 at91_pmc_write(AT91_CKGR_UCKR, uckr & ~(clk->pmc_mask));
164
165 do {
166 cpu_relax();
167 } while ((at91_pmc_read(AT91_PMC_SR) & AT91_PMC_LOCKU) != is_on);
168 }
169
170 /* USB function clocks (PLLB must be 48 MHz) */
171 static struct clk udpck = {
172 .name = "udpck",
173 .parent = &pllb,
174 .mode = pmc_sys_mode,
175 };
176 struct clk utmi_clk = {
177 .name = "utmi_clk",
178 .parent = &main_clk,
179 .pmc_mask = AT91_PMC_UPLLEN, /* in CKGR_UCKR */
180 .mode = pmc_uckr_mode,
181 .type = CLK_TYPE_PLL,
182 };
183 static struct clk uhpck = {
184 .name = "uhpck",
185 /*.parent = ... we choose parent at runtime */
186 .mode = pmc_sys_mode,
187 };
188
189
190 /*
191 * The master clock is divided from the CPU clock (by 1-4). It's used for
192 * memory, interfaces to on-chip peripherals, the AIC, and sometimes more
193 * (e.g baud rate generation). It's sourced from one of the primary clocks.
194 */
195 struct clk mck = {
196 .name = "mck",
197 .pmc_mask = AT91_PMC_MCKRDY, /* in PMC_SR */
198 };
199
pmc_periph_mode(struct clk * clk,int is_on)200 static void pmc_periph_mode(struct clk *clk, int is_on)
201 {
202 if (is_on)
203 at91_pmc_write(AT91_PMC_PCER, clk->pmc_mask);
204 else
205 at91_pmc_write(AT91_PMC_PCDR, clk->pmc_mask);
206 }
207
at91_css_to_clk(unsigned long css)208 static struct clk __init *at91_css_to_clk(unsigned long css)
209 {
210 switch (css) {
211 case AT91_PMC_CSS_SLOW:
212 return &clk32k;
213 case AT91_PMC_CSS_MAIN:
214 return &main_clk;
215 case AT91_PMC_CSS_PLLA:
216 return &plla;
217 case AT91_PMC_CSS_PLLB:
218 if (cpu_has_upll())
219 /* CSS_PLLB == CSS_UPLL */
220 return &utmi_clk;
221 else if (cpu_has_pllb())
222 return &pllb;
223 break;
224 /* alternate PMC: can use master clock */
225 case AT91_PMC_CSS_MASTER:
226 return &mck;
227 }
228
229 return NULL;
230 }
231
pmc_prescaler_divider(u32 reg)232 static int pmc_prescaler_divider(u32 reg)
233 {
234 if (cpu_has_alt_prescaler()) {
235 return 1 << ((reg & AT91_PMC_ALT_PRES) >> PMC_ALT_PRES_OFFSET);
236 } else {
237 return 1 << ((reg & AT91_PMC_PRES) >> PMC_PRES_OFFSET);
238 }
239 }
240
__clk_enable(struct clk * clk)241 static void __clk_enable(struct clk *clk)
242 {
243 if (clk->parent)
244 __clk_enable(clk->parent);
245 if (clk->users++ == 0 && clk->mode)
246 clk->mode(clk, 1);
247 }
248
clk_enable(struct clk * clk)249 int clk_enable(struct clk *clk)
250 {
251 unsigned long flags;
252
253 spin_lock_irqsave(&clk_lock, flags);
254 __clk_enable(clk);
255 spin_unlock_irqrestore(&clk_lock, flags);
256 return 0;
257 }
258 EXPORT_SYMBOL(clk_enable);
259
__clk_disable(struct clk * clk)260 static void __clk_disable(struct clk *clk)
261 {
262 BUG_ON(clk->users == 0);
263 if (--clk->users == 0 && clk->mode)
264 clk->mode(clk, 0);
265 if (clk->parent)
266 __clk_disable(clk->parent);
267 }
268
clk_disable(struct clk * clk)269 void clk_disable(struct clk *clk)
270 {
271 unsigned long flags;
272
273 spin_lock_irqsave(&clk_lock, flags);
274 __clk_disable(clk);
275 spin_unlock_irqrestore(&clk_lock, flags);
276 }
277 EXPORT_SYMBOL(clk_disable);
278
clk_get_rate(struct clk * clk)279 unsigned long clk_get_rate(struct clk *clk)
280 {
281 unsigned long flags;
282 unsigned long rate;
283
284 spin_lock_irqsave(&clk_lock, flags);
285 for (;;) {
286 rate = clk->rate_hz;
287 if (rate || !clk->parent)
288 break;
289 clk = clk->parent;
290 }
291 spin_unlock_irqrestore(&clk_lock, flags);
292 return rate;
293 }
294 EXPORT_SYMBOL(clk_get_rate);
295
296 /*------------------------------------------------------------------------*/
297
298 #ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
299
300 /*
301 * For now, only the programmable clocks support reparenting (MCK could
302 * do this too, with care) or rate changing (the PLLs could do this too,
303 * ditto MCK but that's more for cpufreq). Drivers may reparent to get
304 * a better rate match; we don't.
305 */
306
clk_round_rate(struct clk * clk,unsigned long rate)307 long clk_round_rate(struct clk *clk, unsigned long rate)
308 {
309 unsigned long flags;
310 unsigned prescale;
311 unsigned long actual;
312 unsigned long prev = ULONG_MAX;
313
314 if (!clk_is_programmable(clk))
315 return -EINVAL;
316 spin_lock_irqsave(&clk_lock, flags);
317
318 actual = clk->parent->rate_hz;
319 for (prescale = 0; prescale < 7; prescale++) {
320 if (actual > rate)
321 prev = actual;
322
323 if (actual && actual <= rate) {
324 if ((prev - rate) < (rate - actual)) {
325 actual = prev;
326 prescale--;
327 }
328 break;
329 }
330 actual >>= 1;
331 }
332
333 spin_unlock_irqrestore(&clk_lock, flags);
334 return (prescale < 7) ? actual : -ENOENT;
335 }
336 EXPORT_SYMBOL(clk_round_rate);
337
clk_set_rate(struct clk * clk,unsigned long rate)338 int clk_set_rate(struct clk *clk, unsigned long rate)
339 {
340 unsigned long flags;
341 unsigned prescale;
342 unsigned long prescale_offset, css_mask;
343 unsigned long actual;
344
345 if (!clk_is_programmable(clk))
346 return -EINVAL;
347 if (clk->users)
348 return -EBUSY;
349
350 if (cpu_has_alt_prescaler()) {
351 prescale_offset = PMC_ALT_PRES_OFFSET;
352 css_mask = AT91_PMC_ALT_PCKR_CSS;
353 } else {
354 prescale_offset = PMC_PRES_OFFSET;
355 css_mask = AT91_PMC_CSS;
356 }
357
358 spin_lock_irqsave(&clk_lock, flags);
359
360 actual = clk->parent->rate_hz;
361 for (prescale = 0; prescale < 7; prescale++) {
362 if (actual && actual <= rate) {
363 u32 pckr;
364
365 pckr = at91_pmc_read(AT91_PMC_PCKR(clk->id));
366 pckr &= css_mask; /* keep clock selection */
367 pckr |= prescale << prescale_offset;
368 at91_pmc_write(AT91_PMC_PCKR(clk->id), pckr);
369 clk->rate_hz = actual;
370 break;
371 }
372 actual >>= 1;
373 }
374
375 spin_unlock_irqrestore(&clk_lock, flags);
376 return (prescale < 7) ? actual : -ENOENT;
377 }
378 EXPORT_SYMBOL(clk_set_rate);
379
clk_get_parent(struct clk * clk)380 struct clk *clk_get_parent(struct clk *clk)
381 {
382 return clk->parent;
383 }
384 EXPORT_SYMBOL(clk_get_parent);
385
clk_set_parent(struct clk * clk,struct clk * parent)386 int clk_set_parent(struct clk *clk, struct clk *parent)
387 {
388 unsigned long flags;
389
390 if (clk->users)
391 return -EBUSY;
392 if (!clk_is_primary(parent) || !clk_is_programmable(clk))
393 return -EINVAL;
394
395 if (cpu_is_at91sam9rl() && parent->id == AT91_PMC_CSS_PLLB)
396 return -EINVAL;
397
398 spin_lock_irqsave(&clk_lock, flags);
399
400 clk->rate_hz = parent->rate_hz;
401 clk->parent = parent;
402 at91_pmc_write(AT91_PMC_PCKR(clk->id), parent->id);
403
404 spin_unlock_irqrestore(&clk_lock, flags);
405 return 0;
406 }
407 EXPORT_SYMBOL(clk_set_parent);
408
409 /* establish PCK0..PCKN parentage and rate */
init_programmable_clock(struct clk * clk)410 static void __init init_programmable_clock(struct clk *clk)
411 {
412 struct clk *parent;
413 u32 pckr;
414 unsigned int css_mask;
415
416 if (cpu_has_alt_prescaler())
417 css_mask = AT91_PMC_ALT_PCKR_CSS;
418 else
419 css_mask = AT91_PMC_CSS;
420
421 pckr = at91_pmc_read(AT91_PMC_PCKR(clk->id));
422 parent = at91_css_to_clk(pckr & css_mask);
423 clk->parent = parent;
424 clk->rate_hz = parent->rate_hz / pmc_prescaler_divider(pckr);
425 }
426
427 #endif /* CONFIG_AT91_PROGRAMMABLE_CLOCKS */
428
429 /*------------------------------------------------------------------------*/
430
431 #ifdef CONFIG_DEBUG_FS
432
at91_clk_show(struct seq_file * s,void * unused)433 static int at91_clk_show(struct seq_file *s, void *unused)
434 {
435 u32 scsr, pcsr, uckr = 0, sr;
436 struct clk *clk;
437
438 scsr = at91_pmc_read(AT91_PMC_SCSR);
439 pcsr = at91_pmc_read(AT91_PMC_PCSR);
440 sr = at91_pmc_read(AT91_PMC_SR);
441 seq_printf(s, "SCSR = %8x\n", scsr);
442 seq_printf(s, "PCSR = %8x\n", pcsr);
443 seq_printf(s, "MOR = %8x\n", at91_pmc_read(AT91_CKGR_MOR));
444 seq_printf(s, "MCFR = %8x\n", at91_pmc_read(AT91_CKGR_MCFR));
445 seq_printf(s, "PLLA = %8x\n", at91_pmc_read(AT91_CKGR_PLLAR));
446 if (cpu_has_pllb())
447 seq_printf(s, "PLLB = %8x\n", at91_pmc_read(AT91_CKGR_PLLBR));
448 if (cpu_has_utmi()) {
449 uckr = at91_pmc_read(AT91_CKGR_UCKR);
450 seq_printf(s, "UCKR = %8x\n", uckr);
451 }
452 seq_printf(s, "MCKR = %8x\n", at91_pmc_read(AT91_PMC_MCKR));
453 if (cpu_has_upll())
454 seq_printf(s, "USB = %8x\n", at91_pmc_read(AT91_PMC_USB));
455 seq_printf(s, "SR = %8x\n", sr);
456
457 seq_printf(s, "\n");
458
459 list_for_each_entry(clk, &clocks, node) {
460 char *state;
461
462 if (clk->mode == pmc_sys_mode)
463 state = (scsr & clk->pmc_mask) ? "on" : "off";
464 else if (clk->mode == pmc_periph_mode)
465 state = (pcsr & clk->pmc_mask) ? "on" : "off";
466 else if (clk->mode == pmc_uckr_mode)
467 state = (uckr & clk->pmc_mask) ? "on" : "off";
468 else if (clk->pmc_mask)
469 state = (sr & clk->pmc_mask) ? "on" : "off";
470 else if (clk == &clk32k || clk == &main_clk)
471 state = "on";
472 else
473 state = "";
474
475 seq_printf(s, "%-10s users=%2d %-3s %9ld Hz %s\n",
476 clk->name, clk->users, state, clk_get_rate(clk),
477 clk->parent ? clk->parent->name : "");
478 }
479 return 0;
480 }
481
at91_clk_open(struct inode * inode,struct file * file)482 static int at91_clk_open(struct inode *inode, struct file *file)
483 {
484 return single_open(file, at91_clk_show, NULL);
485 }
486
487 static const struct file_operations at91_clk_operations = {
488 .open = at91_clk_open,
489 .read = seq_read,
490 .llseek = seq_lseek,
491 .release = single_release,
492 };
493
at91_clk_debugfs_init(void)494 static int __init at91_clk_debugfs_init(void)
495 {
496 /* /sys/kernel/debug/at91_clk */
497 (void) debugfs_create_file("at91_clk", S_IFREG | S_IRUGO, NULL, NULL, &at91_clk_operations);
498
499 return 0;
500 }
501 postcore_initcall(at91_clk_debugfs_init);
502
503 #endif
504
505 /*------------------------------------------------------------------------*/
506
507 /* Register a new clock */
at91_clk_add(struct clk * clk)508 static void __init at91_clk_add(struct clk *clk)
509 {
510 list_add_tail(&clk->node, &clocks);
511
512 clk->cl.con_id = clk->name;
513 clk->cl.clk = clk;
514 clkdev_add(&clk->cl);
515 }
516
clk_register(struct clk * clk)517 int __init clk_register(struct clk *clk)
518 {
519 if (clk_is_peripheral(clk)) {
520 if (!clk->parent)
521 clk->parent = &mck;
522 clk->mode = pmc_periph_mode;
523 }
524 else if (clk_is_sys(clk)) {
525 clk->parent = &mck;
526 clk->mode = pmc_sys_mode;
527 }
528 #ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
529 else if (clk_is_programmable(clk)) {
530 clk->mode = pmc_sys_mode;
531 init_programmable_clock(clk);
532 }
533 #endif
534
535 at91_clk_add(clk);
536
537 return 0;
538 }
539
540 /*------------------------------------------------------------------------*/
541
at91_pll_rate(struct clk * pll,u32 freq,u32 reg)542 static u32 __init at91_pll_rate(struct clk *pll, u32 freq, u32 reg)
543 {
544 unsigned mul, div;
545
546 div = reg & 0xff;
547 mul = (reg >> 16) & 0x7ff;
548 if (div && mul) {
549 freq /= div;
550 freq *= mul + 1;
551 } else
552 freq = 0;
553
554 return freq;
555 }
556
at91_usb_rate(struct clk * pll,u32 freq,u32 reg)557 static u32 __init at91_usb_rate(struct clk *pll, u32 freq, u32 reg)
558 {
559 if (pll == &pllb && (reg & AT91_PMC_USB96M))
560 return freq / 2;
561 else
562 return freq;
563 }
564
at91_pll_calc(unsigned main_freq,unsigned out_freq)565 static unsigned __init at91_pll_calc(unsigned main_freq, unsigned out_freq)
566 {
567 unsigned i, div = 0, mul = 0, diff = 1 << 30;
568 unsigned ret = (out_freq > 155000000) ? 0xbe00 : 0x3e00;
569
570 /* PLL output max 240 MHz (or 180 MHz per errata) */
571 if (out_freq > 240000000)
572 goto fail;
573
574 for (i = 1; i < 256; i++) {
575 int diff1;
576 unsigned input, mul1;
577
578 /*
579 * PLL input between 1MHz and 32MHz per spec, but lower
580 * frequences seem necessary in some cases so allow 100K.
581 * Warning: some newer products need 2MHz min.
582 */
583 input = main_freq / i;
584 if (cpu_is_at91sam9g20() && input < 2000000)
585 continue;
586 if (input < 100000)
587 continue;
588 if (input > 32000000)
589 continue;
590
591 mul1 = out_freq / input;
592 if (cpu_is_at91sam9g20() && mul > 63)
593 continue;
594 if (mul1 > 2048)
595 continue;
596 if (mul1 < 2)
597 goto fail;
598
599 diff1 = out_freq - input * mul1;
600 if (diff1 < 0)
601 diff1 = -diff1;
602 if (diff > diff1) {
603 diff = diff1;
604 div = i;
605 mul = mul1;
606 if (diff == 0)
607 break;
608 }
609 }
610 if (i == 256 && diff > (out_freq >> 5))
611 goto fail;
612 return ret | ((mul - 1) << 16) | div;
613 fail:
614 return 0;
615 }
616
617 static struct clk *const standard_pmc_clocks[] __initdata = {
618 /* four primary clocks */
619 &clk32k,
620 &main_clk,
621 &plla,
622
623 /* MCK */
624 &mck
625 };
626
627 /* PLLB generated USB full speed clock init */
at91_pllb_usbfs_clock_init(unsigned long main_clock)628 static void __init at91_pllb_usbfs_clock_init(unsigned long main_clock)
629 {
630 /*
631 * USB clock init: choose 48 MHz PLLB value,
632 * disable 48MHz clock during usb peripheral suspend.
633 *
634 * REVISIT: assumes MCK doesn't derive from PLLB!
635 */
636 uhpck.parent = &pllb;
637
638 at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2) | AT91_PMC_USB96M;
639 pllb.rate_hz = at91_pll_rate(&pllb, main_clock, at91_pllb_usb_init);
640 if (cpu_is_at91rm9200()) {
641 uhpck.pmc_mask = AT91RM9200_PMC_UHP;
642 udpck.pmc_mask = AT91RM9200_PMC_UDP;
643 at91_pmc_write(AT91_PMC_SCER, AT91RM9200_PMC_MCKUDP);
644 } else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() ||
645 cpu_is_at91sam9263() || cpu_is_at91sam9g20() ||
646 cpu_is_at91sam9g10()) {
647 uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
648 udpck.pmc_mask = AT91SAM926x_PMC_UDP;
649 }
650 at91_pmc_write(AT91_CKGR_PLLBR, 0);
651
652 udpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init);
653 uhpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init);
654 }
655
656 /* UPLL generated USB full speed clock init */
at91_upll_usbfs_clock_init(unsigned long main_clock)657 static void __init at91_upll_usbfs_clock_init(unsigned long main_clock)
658 {
659 /*
660 * USB clock init: choose 480 MHz from UPLL,
661 */
662 unsigned int usbr = AT91_PMC_USBS_UPLL;
663
664 /* Setup divider by 10 to reach 48 MHz */
665 usbr |= ((10 - 1) << 8) & AT91_PMC_OHCIUSBDIV;
666
667 at91_pmc_write(AT91_PMC_USB, usbr);
668
669 /* Now set uhpck values */
670 uhpck.parent = &utmi_clk;
671 uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
672 uhpck.rate_hz = utmi_clk.rate_hz;
673 uhpck.rate_hz /= 1 + ((at91_pmc_read(AT91_PMC_USB) & AT91_PMC_OHCIUSBDIV) >> 8);
674 }
675
at91_pmc_init(unsigned long main_clock)676 static int __init at91_pmc_init(unsigned long main_clock)
677 {
678 unsigned tmp, freq, mckr;
679 int i;
680 int pll_overclock = false;
681
682 /*
683 * When the bootloader initialized the main oscillator correctly,
684 * there's no problem using the cycle counter. But if it didn't,
685 * or when using oscillator bypass mode, we must be told the speed
686 * of the main clock.
687 */
688 if (!main_clock) {
689 do {
690 tmp = at91_pmc_read(AT91_CKGR_MCFR);
691 } while (!(tmp & AT91_PMC_MAINRDY));
692 main_clock = (tmp & AT91_PMC_MAINF) * (AT91_SLOW_CLOCK / 16);
693 }
694 main_clk.rate_hz = main_clock;
695
696 /* report if PLLA is more than mildly overclocked */
697 plla.rate_hz = at91_pll_rate(&plla, main_clock, at91_pmc_read(AT91_CKGR_PLLAR));
698 if (cpu_has_300M_plla()) {
699 if (plla.rate_hz > 300000000)
700 pll_overclock = true;
701 } else if (cpu_has_800M_plla()) {
702 if (plla.rate_hz > 800000000)
703 pll_overclock = true;
704 } else {
705 if (plla.rate_hz > 209000000)
706 pll_overclock = true;
707 }
708 if (pll_overclock)
709 pr_info("Clocks: PLLA overclocked, %ld MHz\n", plla.rate_hz / 1000000);
710
711 if (cpu_has_plladiv2()) {
712 mckr = at91_pmc_read(AT91_PMC_MCKR);
713 plla.rate_hz /= (1 << ((mckr & AT91_PMC_PLLADIV2) >> 12)); /* plla divisor by 2 */
714 }
715
716 if (!cpu_has_pllb() && cpu_has_upll()) {
717 /* setup UTMI clock as the fourth primary clock
718 * (instead of pllb) */
719 utmi_clk.type |= CLK_TYPE_PRIMARY;
720 utmi_clk.id = 3;
721 }
722
723
724 /*
725 * USB HS clock init
726 */
727 if (cpu_has_utmi()) {
728 /*
729 * multiplier is hard-wired to 40
730 * (obtain the USB High Speed 480 MHz when input is 12 MHz)
731 */
732 utmi_clk.rate_hz = 40 * utmi_clk.parent->rate_hz;
733
734 /* UTMI bias and PLL are managed at the same time */
735 if (cpu_has_upll())
736 utmi_clk.pmc_mask |= AT91_PMC_BIASEN;
737 }
738
739 /*
740 * USB FS clock init
741 */
742 if (cpu_has_pllb())
743 at91_pllb_usbfs_clock_init(main_clock);
744 if (cpu_has_upll())
745 /* assumes that we choose UPLL for USB and not PLLA */
746 at91_upll_usbfs_clock_init(main_clock);
747
748 /*
749 * MCK and CPU derive from one of those primary clocks.
750 * For now, assume this parentage won't change.
751 */
752 mckr = at91_pmc_read(AT91_PMC_MCKR);
753 mck.parent = at91_css_to_clk(mckr & AT91_PMC_CSS);
754 freq = mck.parent->rate_hz;
755 freq /= pmc_prescaler_divider(mckr); /* prescale */
756 if (cpu_is_at91rm9200()) {
757 mck.rate_hz = freq / (1 + ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
758 } else if (cpu_is_at91sam9g20()) {
759 mck.rate_hz = (mckr & AT91_PMC_MDIV) ?
760 freq / ((mckr & AT91_PMC_MDIV) >> 7) : freq; /* mdiv ; (x >> 7) = ((x >> 8) * 2) */
761 if (mckr & AT91_PMC_PDIV)
762 freq /= 2; /* processor clock division */
763 } else if (cpu_has_mdiv3()) {
764 mck.rate_hz = (mckr & AT91_PMC_MDIV) == AT91SAM9_PMC_MDIV_3 ?
765 freq / 3 : freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
766 } else {
767 mck.rate_hz = freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
768 }
769
770 if (cpu_has_alt_prescaler()) {
771 /* Programmable clocks can use MCK */
772 mck.type |= CLK_TYPE_PRIMARY;
773 mck.id = 4;
774 }
775
776 /* Register the PMC's standard clocks */
777 for (i = 0; i < ARRAY_SIZE(standard_pmc_clocks); i++)
778 at91_clk_add(standard_pmc_clocks[i]);
779
780 if (cpu_has_pllb())
781 at91_clk_add(&pllb);
782
783 if (cpu_has_uhp())
784 at91_clk_add(&uhpck);
785
786 if (cpu_has_udpfs())
787 at91_clk_add(&udpck);
788
789 if (cpu_has_utmi())
790 at91_clk_add(&utmi_clk);
791
792 /* MCK and CPU clock are "always on" */
793 clk_enable(&mck);
794
795 printk("Clocks: CPU %u MHz, master %u MHz, main %u.%03u MHz\n",
796 freq / 1000000, (unsigned) mck.rate_hz / 1000000,
797 (unsigned) main_clock / 1000000,
798 ((unsigned) main_clock % 1000000) / 1000);
799
800 return 0;
801 }
802
803 #if defined(CONFIG_OF)
804 static struct of_device_id pmc_ids[] = {
805 { .compatible = "atmel,at91rm9200-pmc" },
806 { /*sentinel*/ }
807 };
808
809 static struct of_device_id osc_ids[] = {
810 { .compatible = "atmel,osc" },
811 { /*sentinel*/ }
812 };
813
at91_dt_clock_init(void)814 int __init at91_dt_clock_init(void)
815 {
816 struct device_node *np;
817 u32 main_clock = 0;
818
819 np = of_find_matching_node(NULL, pmc_ids);
820 if (!np)
821 panic("unable to find compatible pmc node in dtb\n");
822
823 at91_pmc_base = of_iomap(np, 0);
824 if (!at91_pmc_base)
825 panic("unable to map pmc cpu registers\n");
826
827 of_node_put(np);
828
829 /* retrieve the freqency of fixed clocks from device tree */
830 np = of_find_matching_node(NULL, osc_ids);
831 if (np) {
832 u32 rate;
833 if (!of_property_read_u32(np, "clock-frequency", &rate))
834 main_clock = rate;
835 }
836
837 of_node_put(np);
838
839 return at91_pmc_init(main_clock);
840 }
841 #endif
842
at91_clock_init(unsigned long main_clock)843 int __init at91_clock_init(unsigned long main_clock)
844 {
845 at91_pmc_base = ioremap(AT91_PMC, 256);
846 if (!at91_pmc_base)
847 panic("Impossible to ioremap AT91_PMC 0x%x\n", AT91_PMC);
848
849 return at91_pmc_init(main_clock);
850 }
851
852 /*
853 * Several unused clocks may be active. Turn them off.
854 */
at91_clock_reset(void)855 static int __init at91_clock_reset(void)
856 {
857 unsigned long pcdr = 0;
858 unsigned long scdr = 0;
859 struct clk *clk;
860
861 list_for_each_entry(clk, &clocks, node) {
862 if (clk->users > 0)
863 continue;
864
865 if (clk->mode == pmc_periph_mode)
866 pcdr |= clk->pmc_mask;
867
868 if (clk->mode == pmc_sys_mode)
869 scdr |= clk->pmc_mask;
870
871 pr_debug("Clocks: disable unused %s\n", clk->name);
872 }
873
874 at91_pmc_write(AT91_PMC_PCDR, pcdr);
875 at91_pmc_write(AT91_PMC_SCDR, scdr);
876
877 return 0;
878 }
879 late_initcall(at91_clock_reset);
880
at91sam9_idle(void)881 void at91sam9_idle(void)
882 {
883 at91_pmc_write(AT91_PMC_SCDR, AT91_PMC_PCK);
884 cpu_do_idle();
885 }
886