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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#include <linux/clk/at91_pmc.h>
28
29#include <mach/hardware.h>
30#include <mach/cpu.h>
31
32#include <asm/proc-fns.h>
33
34#include "clock.h"
35#include "generic.h"
36
37void __iomem *at91_pmc_base;
38EXPORT_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 || cpu_is_sama5d3())
59
60#define cpu_has_1056M_plla() (cpu_is_sama5d3())
61
62#define cpu_has_800M_plla() ( cpu_is_at91sam9g20() \
63 || cpu_is_at91sam9g45() \
64 || cpu_is_at91sam9x5() \
65 || cpu_is_at91sam9n12())
66
67#define cpu_has_300M_plla() (cpu_is_at91sam9g10())
68
69#define cpu_has_240M_plla() (cpu_is_at91sam9261() \
70 || cpu_is_at91sam9263() \
71 || cpu_is_at91sam9rl())
72
73#define cpu_has_210M_plla() (cpu_is_at91sam9260())
74
75#define cpu_has_pllb() (!(cpu_is_at91sam9rl() \
76 || cpu_is_at91sam9g45() \
77 || cpu_is_at91sam9x5() \
78 || cpu_is_sama5d3()))
79
80#define cpu_has_upll() (cpu_is_at91sam9g45() \
81 || cpu_is_at91sam9x5() \
82 || cpu_is_sama5d3())
83
84/* USB host HS & FS */
85#define cpu_has_uhp() (!cpu_is_at91sam9rl())
86
87/* USB device FS only */
88#define cpu_has_udpfs() (!(cpu_is_at91sam9rl() \
89 || cpu_is_at91sam9g45() \
90 || cpu_is_at91sam9x5() \
91 || cpu_is_sama5d3()))
92
93#define cpu_has_plladiv2() (cpu_is_at91sam9g45() \
94 || cpu_is_at91sam9x5() \
95 || cpu_is_at91sam9n12() \
96 || cpu_is_sama5d3())
97
98#define cpu_has_mdiv3() (cpu_is_at91sam9g45() \
99 || cpu_is_at91sam9x5() \
100 || cpu_is_at91sam9n12() \
101 || cpu_is_sama5d3())
102
103#define cpu_has_alt_prescaler() (cpu_is_at91sam9x5() \
104 || cpu_is_at91sam9n12() \
105 || cpu_is_sama5d3())
106
107static LIST_HEAD(clocks);
108static DEFINE_SPINLOCK(clk_lock);
109
110static u32 at91_pllb_usb_init;
111
112/*
113 * Four primary clock sources: two crystal oscillators (32K, main), and
114 * two PLLs. PLLA usually runs the master clock; and PLLB must run at
115 * 48 MHz (unless no USB function clocks are needed). The main clock and
116 * both PLLs are turned off to run in "slow clock mode" (system suspend).
117 */
118static struct clk clk32k = {
119 .name = "clk32k",
120 .rate_hz = AT91_SLOW_CLOCK,
121 .users = 1, /* always on */
122 .id = 0,
123 .type = CLK_TYPE_PRIMARY,
124};
125static struct clk main_clk = {
126 .name = "main",
127 .pmc_mask = AT91_PMC_MOSCS, /* in PMC_SR */
128 .id = 1,
129 .type = CLK_TYPE_PRIMARY,
130};
131static struct clk plla = {
132 .name = "plla",
133 .parent = &main_clk,
134 .pmc_mask = AT91_PMC_LOCKA, /* in PMC_SR */
135 .id = 2,
136 .type = CLK_TYPE_PRIMARY | CLK_TYPE_PLL,
137};
138
139static void pllb_mode(struct clk *clk, int is_on)
140{
141 u32 value;
142
143 if (is_on) {
144 is_on = AT91_PMC_LOCKB;
145 value = at91_pllb_usb_init;
146 } else
147 value = 0;
148
149 // REVISIT: Add work-around for AT91RM9200 Errata #26 ?
150 at91_pmc_write(AT91_CKGR_PLLBR, value);
151
152 do {
153 cpu_relax();
154 } while ((at91_pmc_read(AT91_PMC_SR) & AT91_PMC_LOCKB) != is_on);
155}
156
157static struct clk pllb = {
158 .name = "pllb",
159 .parent = &main_clk,
160 .pmc_mask = AT91_PMC_LOCKB, /* in PMC_SR */
161 .mode = pllb_mode,
162 .id = 3,
163 .type = CLK_TYPE_PRIMARY | CLK_TYPE_PLL,
164};
165
166static void pmc_sys_mode(struct clk *clk, int is_on)
167{
168 if (is_on)
169 at91_pmc_write(AT91_PMC_SCER, clk->pmc_mask);
170 else
171 at91_pmc_write(AT91_PMC_SCDR, clk->pmc_mask);
172}
173
174static void pmc_uckr_mode(struct clk *clk, int is_on)
175{
176 unsigned int uckr = at91_pmc_read(AT91_CKGR_UCKR);
177
178 if (is_on) {
179 is_on = AT91_PMC_LOCKU;
180 at91_pmc_write(AT91_CKGR_UCKR, uckr | clk->pmc_mask);
181 } else
182 at91_pmc_write(AT91_CKGR_UCKR, uckr & ~(clk->pmc_mask));
183
184 do {
185 cpu_relax();
186 } while ((at91_pmc_read(AT91_PMC_SR) & AT91_PMC_LOCKU) != is_on);
187}
188
189/* USB function clocks (PLLB must be 48 MHz) */
190static struct clk udpck = {
191 .name = "udpck",
192 .parent = &pllb,
193 .mode = pmc_sys_mode,
194};
195struct clk utmi_clk = {
196 .name = "utmi_clk",
197 .parent = &main_clk,
198 .pmc_mask = AT91_PMC_UPLLEN, /* in CKGR_UCKR */
199 .mode = pmc_uckr_mode,
200 .type = CLK_TYPE_PLL,
201};
202static struct clk uhpck = {
203 .name = "uhpck",
204 /*.parent = ... we choose parent at runtime */
205 .mode = pmc_sys_mode,
206};
207
208
209/*
210 * The master clock is divided from the CPU clock (by 1-4). It's used for
211 * memory, interfaces to on-chip peripherals, the AIC, and sometimes more
212 * (e.g baud rate generation). It's sourced from one of the primary clocks.
213 */
214struct clk mck = {
215 .name = "mck",
216 .pmc_mask = AT91_PMC_MCKRDY, /* in PMC_SR */
217};
218
219static void pmc_periph_mode(struct clk *clk, int is_on)
220{
221 u32 regval = 0;
222
223 /*
224 * With sama5d3 devices, we are managing clock division so we have to
225 * use the Peripheral Control Register introduced from at91sam9x5
226 * devices.
227 */
228 if (cpu_is_sama5d3()) {
229 regval |= AT91_PMC_PCR_CMD; /* write command */
230 regval |= clk->pid & AT91_PMC_PCR_PID; /* peripheral selection */
231 regval |= AT91_PMC_PCR_DIV(clk->div);
232 if (is_on)
233 regval |= AT91_PMC_PCR_EN; /* enable clock */
234 at91_pmc_write(AT91_PMC_PCR, regval);
235 } else {
236 if (is_on)
237 at91_pmc_write(AT91_PMC_PCER, clk->pmc_mask);
238 else
239 at91_pmc_write(AT91_PMC_PCDR, clk->pmc_mask);
240 }
241}
242
243static struct clk __init *at91_css_to_clk(unsigned long css)
244{
245 switch (css) {
246 case AT91_PMC_CSS_SLOW:
247 return &clk32k;
248 case AT91_PMC_CSS_MAIN:
249 return &main_clk;
250 case AT91_PMC_CSS_PLLA:
251 return &plla;
252 case AT91_PMC_CSS_PLLB:
253 if (cpu_has_upll())
254 /* CSS_PLLB == CSS_UPLL */
255 return &utmi_clk;
256 else if (cpu_has_pllb())
257 return &pllb;
258 break;
259 /* alternate PMC: can use master clock */
260 case AT91_PMC_CSS_MASTER:
261 return &mck;
262 }
263
264 return NULL;
265}
266
267static int pmc_prescaler_divider(u32 reg)
268{
269 if (cpu_has_alt_prescaler()) {
270 return 1 << ((reg & AT91_PMC_ALT_PRES) >> PMC_ALT_PRES_OFFSET);
271 } else {
272 return 1 << ((reg & AT91_PMC_PRES) >> PMC_PRES_OFFSET);
273 }
274}
275
276static void __clk_enable(struct clk *clk)
277{
278 if (clk->parent)
279 __clk_enable(clk->parent);
280 if (clk->users++ == 0 && clk->mode)
281 clk->mode(clk, 1);
282}
283
284int clk_enable(struct clk *clk)
285{
286 unsigned long flags;
287
288 spin_lock_irqsave(&clk_lock, flags);
289 __clk_enable(clk);
290 spin_unlock_irqrestore(&clk_lock, flags);
291 return 0;
292}
293EXPORT_SYMBOL(clk_enable);
294
295static void __clk_disable(struct clk *clk)
296{
297 BUG_ON(clk->users == 0);
298 if (--clk->users == 0 && clk->mode)
299 clk->mode(clk, 0);
300 if (clk->parent)
301 __clk_disable(clk->parent);
302}
303
304void clk_disable(struct clk *clk)
305{
306 unsigned long flags;
307
308 spin_lock_irqsave(&clk_lock, flags);
309 __clk_disable(clk);
310 spin_unlock_irqrestore(&clk_lock, flags);
311}
312EXPORT_SYMBOL(clk_disable);
313
314unsigned long clk_get_rate(struct clk *clk)
315{
316 unsigned long flags;
317 unsigned long rate;
318
319 spin_lock_irqsave(&clk_lock, flags);
320 for (;;) {
321 rate = clk->rate_hz;
322 if (rate || !clk->parent)
323 break;
324 clk = clk->parent;
325 }
326 spin_unlock_irqrestore(&clk_lock, flags);
327 return rate;
328}
329EXPORT_SYMBOL(clk_get_rate);
330
331/*------------------------------------------------------------------------*/
332
333/*
334 * For now, only the programmable clocks support reparenting (MCK could
335 * do this too, with care) or rate changing (the PLLs could do this too,
336 * ditto MCK but that's more for cpufreq). Drivers may reparent to get
337 * a better rate match; we don't.
338 */
339
340long clk_round_rate(struct clk *clk, unsigned long rate)
341{
342 unsigned long flags;
343 unsigned prescale;
344 unsigned long actual;
345 unsigned long prev = ULONG_MAX;
346
347 if (!clk_is_programmable(clk))
348 return -EINVAL;
349 spin_lock_irqsave(&clk_lock, flags);
350
351 actual = clk->parent->rate_hz;
352 for (prescale = 0; prescale < 7; prescale++) {
353 if (actual > rate)
354 prev = actual;
355
356 if (actual && actual <= rate) {
357 if ((prev - rate) < (rate - actual)) {
358 actual = prev;
359 prescale--;
360 }
361 break;
362 }
363 actual >>= 1;
364 }
365
366 spin_unlock_irqrestore(&clk_lock, flags);
367 return (prescale < 7) ? actual : -ENOENT;
368}
369EXPORT_SYMBOL(clk_round_rate);
370
371int clk_set_rate(struct clk *clk, unsigned long rate)
372{
373 unsigned long flags;
374 unsigned prescale;
375 unsigned long prescale_offset, css_mask;
376 unsigned long actual;
377
378 if (!clk_is_programmable(clk))
379 return -EINVAL;
380 if (clk->users)
381 return -EBUSY;
382
383 if (cpu_has_alt_prescaler()) {
384 prescale_offset = PMC_ALT_PRES_OFFSET;
385 css_mask = AT91_PMC_ALT_PCKR_CSS;
386 } else {
387 prescale_offset = PMC_PRES_OFFSET;
388 css_mask = AT91_PMC_CSS;
389 }
390
391 spin_lock_irqsave(&clk_lock, flags);
392
393 actual = clk->parent->rate_hz;
394 for (prescale = 0; prescale < 7; prescale++) {
395 if (actual && actual <= rate) {
396 u32 pckr;
397
398 pckr = at91_pmc_read(AT91_PMC_PCKR(clk->id));
399 pckr &= css_mask; /* keep clock selection */
400 pckr |= prescale << prescale_offset;
401 at91_pmc_write(AT91_PMC_PCKR(clk->id), pckr);
402 clk->rate_hz = actual;
403 break;
404 }
405 actual >>= 1;
406 }
407
408 spin_unlock_irqrestore(&clk_lock, flags);
409 return (prescale < 7) ? actual : -ENOENT;
410}
411EXPORT_SYMBOL(clk_set_rate);
412
413struct clk *clk_get_parent(struct clk *clk)
414{
415 return clk->parent;
416}
417EXPORT_SYMBOL(clk_get_parent);
418
419int clk_set_parent(struct clk *clk, struct clk *parent)
420{
421 unsigned long flags;
422
423 if (clk->users)
424 return -EBUSY;
425 if (!clk_is_primary(parent) || !clk_is_programmable(clk))
426 return -EINVAL;
427
428 if (cpu_is_at91sam9rl() && parent->id == AT91_PMC_CSS_PLLB)
429 return -EINVAL;
430
431 spin_lock_irqsave(&clk_lock, flags);
432
433 clk->rate_hz = parent->rate_hz;
434 clk->parent = parent;
435 at91_pmc_write(AT91_PMC_PCKR(clk->id), parent->id);
436
437 spin_unlock_irqrestore(&clk_lock, flags);
438 return 0;
439}
440EXPORT_SYMBOL(clk_set_parent);
441
442/* establish PCK0..PCKN parentage and rate */
443static void __init init_programmable_clock(struct clk *clk)
444{
445 struct clk *parent;
446 u32 pckr;
447 unsigned int css_mask;
448
449 if (cpu_has_alt_prescaler())
450 css_mask = AT91_PMC_ALT_PCKR_CSS;
451 else
452 css_mask = AT91_PMC_CSS;
453
454 pckr = at91_pmc_read(AT91_PMC_PCKR(clk->id));
455 parent = at91_css_to_clk(pckr & css_mask);
456 clk->parent = parent;
457 clk->rate_hz = parent->rate_hz / pmc_prescaler_divider(pckr);
458}
459
460/*------------------------------------------------------------------------*/
461
462#ifdef CONFIG_DEBUG_FS
463
464static int at91_clk_show(struct seq_file *s, void *unused)
465{
466 u32 scsr, pcsr, pcsr1 = 0, uckr = 0, sr;
467 struct clk *clk;
468
469 scsr = at91_pmc_read(AT91_PMC_SCSR);
470 pcsr = at91_pmc_read(AT91_PMC_PCSR);
471 if (cpu_is_sama5d3())
472 pcsr1 = at91_pmc_read(AT91_PMC_PCSR1);
473 sr = at91_pmc_read(AT91_PMC_SR);
474 seq_printf(s, "SCSR = %8x\n", scsr);
475 seq_printf(s, "PCSR = %8x\n", pcsr);
476 if (cpu_is_sama5d3())
477 seq_printf(s, "PCSR1 = %8x\n", pcsr1);
478 seq_printf(s, "MOR = %8x\n", at91_pmc_read(AT91_CKGR_MOR));
479 seq_printf(s, "MCFR = %8x\n", at91_pmc_read(AT91_CKGR_MCFR));
480 seq_printf(s, "PLLA = %8x\n", at91_pmc_read(AT91_CKGR_PLLAR));
481 if (cpu_has_pllb())
482 seq_printf(s, "PLLB = %8x\n", at91_pmc_read(AT91_CKGR_PLLBR));
483 if (cpu_has_utmi()) {
484 uckr = at91_pmc_read(AT91_CKGR_UCKR);
485 seq_printf(s, "UCKR = %8x\n", uckr);
486 }
487 seq_printf(s, "MCKR = %8x\n", at91_pmc_read(AT91_PMC_MCKR));
488 if (cpu_has_upll() || cpu_is_at91sam9n12())
489 seq_printf(s, "USB = %8x\n", at91_pmc_read(AT91_PMC_USB));
490 seq_printf(s, "SR = %8x\n", sr);
491
492 seq_printf(s, "\n");
493
494 list_for_each_entry(clk, &clocks, node) {
495 char *state;
496
497 if (clk->mode == pmc_sys_mode) {
498 state = (scsr & clk->pmc_mask) ? "on" : "off";
499 } else if (clk->mode == pmc_periph_mode) {
500 if (cpu_is_sama5d3()) {
501 u32 pmc_mask = 1 << (clk->pid % 32);
502
503 if (clk->pid > 31)
504 state = (pcsr1 & pmc_mask) ? "on" : "off";
505 else
506 state = (pcsr & pmc_mask) ? "on" : "off";
507 } else {
508 state = (pcsr & clk->pmc_mask) ? "on" : "off";
509 }
510 } else if (clk->mode == pmc_uckr_mode) {
511 state = (uckr & clk->pmc_mask) ? "on" : "off";
512 } else if (clk->pmc_mask) {
513 state = (sr & clk->pmc_mask) ? "on" : "off";
514 } else if (clk == &clk32k || clk == &main_clk) {
515 state = "on";
516 } else {
517 state = "";
518 }
519
520 seq_printf(s, "%-10s users=%2d %-3s %9lu Hz %s\n",
521 clk->name, clk->users, state, clk_get_rate(clk),
522 clk->parent ? clk->parent->name : "");
523 }
524 return 0;
525}
526
527static int at91_clk_open(struct inode *inode, struct file *file)
528{
529 return single_open(file, at91_clk_show, NULL);
530}
531
532static const struct file_operations at91_clk_operations = {
533 .open = at91_clk_open,
534 .read = seq_read,
535 .llseek = seq_lseek,
536 .release = single_release,
537};
538
539static int __init at91_clk_debugfs_init(void)
540{
541 /* /sys/kernel/debug/at91_clk */
542 (void) debugfs_create_file("at91_clk", S_IFREG | S_IRUGO, NULL, NULL, &at91_clk_operations);
543
544 return 0;
545}
546postcore_initcall(at91_clk_debugfs_init);
547
548#endif
549
550/*------------------------------------------------------------------------*/
551
552/* Register a new clock */
553static void __init at91_clk_add(struct clk *clk)
554{
555 list_add_tail(&clk->node, &clocks);
556
557 clk->cl.con_id = clk->name;
558 clk->cl.clk = clk;
559 clkdev_add(&clk->cl);
560}
561
562int __init clk_register(struct clk *clk)
563{
564 if (clk_is_peripheral(clk)) {
565 if (!clk->parent)
566 clk->parent = &mck;
567 if (cpu_is_sama5d3())
568 clk->rate_hz = DIV_ROUND_UP(clk->parent->rate_hz,
569 1 << clk->div);
570 clk->mode = pmc_periph_mode;
571 }
572 else if (clk_is_sys(clk)) {
573 clk->parent = &mck;
574 clk->mode = pmc_sys_mode;
575 }
576 else if (clk_is_programmable(clk)) {
577 clk->mode = pmc_sys_mode;
578 init_programmable_clock(clk);
579 }
580
581 at91_clk_add(clk);
582
583 return 0;
584}
585
586/*------------------------------------------------------------------------*/
587
588static u32 __init at91_pll_rate(struct clk *pll, u32 freq, u32 reg)
589{
590 unsigned mul, div;
591
592 div = reg & 0xff;
593 if (cpu_is_sama5d3())
594 mul = AT91_PMC3_MUL_GET(reg);
595 else
596 mul = AT91_PMC_MUL_GET(reg);
597
598 if (div && mul) {
599 freq /= div;
600 freq *= mul + 1;
601 } else
602 freq = 0;
603
604 return freq;
605}
606
607static u32 __init at91_usb_rate(struct clk *pll, u32 freq, u32 reg)
608{
609 if (pll == &pllb && (reg & AT91_PMC_USB96M))
610 return freq / 2;
611 else if (pll == &utmi_clk || cpu_is_at91sam9n12())
612 return freq / (1 + ((reg & AT91_PMC_OHCIUSBDIV) >> 8));
613 else
614 return freq;
615}
616
617static unsigned __init at91_pll_calc(unsigned main_freq, unsigned out_freq)
618{
619 unsigned i, div = 0, mul = 0, diff = 1 << 30;
620 unsigned ret = (out_freq > 155000000) ? 0xbe00 : 0x3e00;
621
622 /* PLL output max 240 MHz (or 180 MHz per errata) */
623 if (out_freq > 240000000)
624 goto fail;
625
626 for (i = 1; i < 256; i++) {
627 int diff1;
628 unsigned input, mul1;
629
630 /*
631 * PLL input between 1MHz and 32MHz per spec, but lower
632 * frequences seem necessary in some cases so allow 100K.
633 * Warning: some newer products need 2MHz min.
634 */
635 input = main_freq / i;
636 if (cpu_is_at91sam9g20() && input < 2000000)
637 continue;
638 if (input < 100000)
639 continue;
640 if (input > 32000000)
641 continue;
642
643 mul1 = out_freq / input;
644 if (cpu_is_at91sam9g20() && mul > 63)
645 continue;
646 if (mul1 > 2048)
647 continue;
648 if (mul1 < 2)
649 goto fail;
650
651 diff1 = out_freq - input * mul1;
652 if (diff1 < 0)
653 diff1 = -diff1;
654 if (diff > diff1) {
655 diff = diff1;
656 div = i;
657 mul = mul1;
658 if (diff == 0)
659 break;
660 }
661 }
662 if (i == 256 && diff > (out_freq >> 5))
663 goto fail;
664 return ret | ((mul - 1) << 16) | div;
665fail:
666 return 0;
667}
668
669static struct clk *const standard_pmc_clocks[] __initconst = {
670 /* four primary clocks */
671 &clk32k,
672 &main_clk,
673 &plla,
674
675 /* MCK */
676 &mck
677};
678
679/* PLLB generated USB full speed clock init */
680static void __init at91_pllb_usbfs_clock_init(unsigned long main_clock)
681{
682 unsigned int reg;
683
684 /*
685 * USB clock init: choose 48 MHz PLLB value,
686 * disable 48MHz clock during usb peripheral suspend.
687 *
688 * REVISIT: assumes MCK doesn't derive from PLLB!
689 */
690 uhpck.parent = &pllb;
691
692 reg = at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2);
693 pllb.rate_hz = at91_pll_rate(&pllb, main_clock, at91_pllb_usb_init);
694 if (cpu_is_at91rm9200()) {
695 reg = at91_pllb_usb_init |= AT91_PMC_USB96M;
696 uhpck.pmc_mask = AT91RM9200_PMC_UHP;
697 udpck.pmc_mask = AT91RM9200_PMC_UDP;
698 at91_pmc_write(AT91_PMC_SCER, AT91RM9200_PMC_MCKUDP);
699 } else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() ||
700 cpu_is_at91sam9263() || cpu_is_at91sam9g20() ||
701 cpu_is_at91sam9g10()) {
702 reg = at91_pllb_usb_init |= AT91_PMC_USB96M;
703 uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
704 udpck.pmc_mask = AT91SAM926x_PMC_UDP;
705 } else if (cpu_is_at91sam9n12()) {
706 /* Divider for USB clock is in USB clock register for 9n12 */
707 reg = AT91_PMC_USBS_PLLB;
708
709 /* For PLLB output 96M, set usb divider 2 (USBDIV + 1) */
710 reg |= AT91_PMC_OHCIUSBDIV_2;
711 at91_pmc_write(AT91_PMC_USB, reg);
712
713 /* Still setup masks */
714 uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
715 udpck.pmc_mask = AT91SAM926x_PMC_UDP;
716 }
717 at91_pmc_write(AT91_CKGR_PLLBR, 0);
718
719 udpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, reg);
720 uhpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, reg);
721}
722
723/* UPLL generated USB full speed clock init */
724static void __init at91_upll_usbfs_clock_init(unsigned long main_clock)
725{
726 /*
727 * USB clock init: choose 480 MHz from UPLL,
728 */
729 unsigned int usbr = AT91_PMC_USBS_UPLL;
730
731 /* Setup divider by 10 to reach 48 MHz */
732 usbr |= ((10 - 1) << 8) & AT91_PMC_OHCIUSBDIV;
733
734 at91_pmc_write(AT91_PMC_USB, usbr);
735
736 /* Now set uhpck values */
737 uhpck.parent = &utmi_clk;
738 uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
739 uhpck.rate_hz = at91_usb_rate(&utmi_clk, utmi_clk.rate_hz, usbr);
740}
741
742static int __init at91_pmc_init(unsigned long main_clock)
743{
744 unsigned tmp, freq, mckr;
745 int i;
746 int pll_overclock = false;
747
748 /*
749 * When the bootloader initialized the main oscillator correctly,
750 * there's no problem using the cycle counter. But if it didn't,
751 * or when using oscillator bypass mode, we must be told the speed
752 * of the main clock.
753 */
754 if (!main_clock) {
755 do {
756 tmp = at91_pmc_read(AT91_CKGR_MCFR);
757 } while (!(tmp & AT91_PMC_MAINRDY));
758 main_clock = (tmp & AT91_PMC_MAINF) * (AT91_SLOW_CLOCK / 16);
759 }
760 main_clk.rate_hz = main_clock;
761
762 /* report if PLLA is more than mildly overclocked */
763 plla.rate_hz = at91_pll_rate(&plla, main_clock, at91_pmc_read(AT91_CKGR_PLLAR));
764 if (cpu_has_1056M_plla()) {
765 if (plla.rate_hz > 1056000000)
766 pll_overclock = true;
767 } else if (cpu_has_800M_plla()) {
768 if (plla.rate_hz > 800000000)
769 pll_overclock = true;
770 } else if (cpu_has_300M_plla()) {
771 if (plla.rate_hz > 300000000)
772 pll_overclock = true;
773 } else if (cpu_has_240M_plla()) {
774 if (plla.rate_hz > 240000000)
775 pll_overclock = true;
776 } else if (cpu_has_210M_plla()) {
777 if (plla.rate_hz > 210000000)
778 pll_overclock = true;
779 } else {
780 if (plla.rate_hz > 209000000)
781 pll_overclock = true;
782 }
783 if (pll_overclock)
784 pr_info("Clocks: PLLA overclocked, %ld MHz\n", plla.rate_hz / 1000000);
785
786 if (cpu_has_plladiv2()) {
787 mckr = at91_pmc_read(AT91_PMC_MCKR);
788 plla.rate_hz /= (1 << ((mckr & AT91_PMC_PLLADIV2) >> 12)); /* plla divisor by 2 */
789 }
790
791 if (!cpu_has_pllb() && cpu_has_upll()) {
792 /* setup UTMI clock as the fourth primary clock
793 * (instead of pllb) */
794 utmi_clk.type |= CLK_TYPE_PRIMARY;
795 utmi_clk.id = 3;
796 }
797
798
799 /*
800 * USB HS clock init
801 */
802 if (cpu_has_utmi()) {
803 /*
804 * multiplier is hard-wired to 40
805 * (obtain the USB High Speed 480 MHz when input is 12 MHz)
806 */
807 utmi_clk.rate_hz = 40 * utmi_clk.parent->rate_hz;
808
809 /* UTMI bias and PLL are managed at the same time */
810 if (cpu_has_upll())
811 utmi_clk.pmc_mask |= AT91_PMC_BIASEN;
812 }
813
814 /*
815 * USB FS clock init
816 */
817 if (cpu_has_pllb())
818 at91_pllb_usbfs_clock_init(main_clock);
819 if (cpu_has_upll())
820 /* assumes that we choose UPLL for USB and not PLLA */
821 at91_upll_usbfs_clock_init(main_clock);
822
823 /*
824 * MCK and CPU derive from one of those primary clocks.
825 * For now, assume this parentage won't change.
826 */
827 mckr = at91_pmc_read(AT91_PMC_MCKR);
828 mck.parent = at91_css_to_clk(mckr & AT91_PMC_CSS);
829 freq = mck.parent->rate_hz;
830 freq /= pmc_prescaler_divider(mckr); /* prescale */
831 if (cpu_is_at91rm9200()) {
832 mck.rate_hz = freq / (1 + ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
833 } else if (cpu_is_at91sam9g20()) {
834 mck.rate_hz = (mckr & AT91_PMC_MDIV) ?
835 freq / ((mckr & AT91_PMC_MDIV) >> 7) : freq; /* mdiv ; (x >> 7) = ((x >> 8) * 2) */
836 if (mckr & AT91_PMC_PDIV)
837 freq /= 2; /* processor clock division */
838 } else if (cpu_has_mdiv3()) {
839 mck.rate_hz = (mckr & AT91_PMC_MDIV) == AT91SAM9_PMC_MDIV_3 ?
840 freq / 3 : freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
841 } else {
842 mck.rate_hz = freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
843 }
844
845 if (cpu_has_alt_prescaler()) {
846 /* Programmable clocks can use MCK */
847 mck.type |= CLK_TYPE_PRIMARY;
848 mck.id = 4;
849 }
850
851 /* Register the PMC's standard clocks */
852 for (i = 0; i < ARRAY_SIZE(standard_pmc_clocks); i++)
853 at91_clk_add(standard_pmc_clocks[i]);
854
855 if (cpu_has_pllb())
856 at91_clk_add(&pllb);
857
858 if (cpu_has_uhp())
859 at91_clk_add(&uhpck);
860
861 if (cpu_has_udpfs())
862 at91_clk_add(&udpck);
863
864 if (cpu_has_utmi())
865 at91_clk_add(&utmi_clk);
866
867 /* MCK and CPU clock are "always on" */
868 clk_enable(&mck);
869
870 printk("Clocks: CPU %u MHz, master %u MHz, main %u.%03u MHz\n",
871 freq / 1000000, (unsigned) mck.rate_hz / 1000000,
872 (unsigned) main_clock / 1000000,
873 ((unsigned) main_clock % 1000000) / 1000);
874
875 return 0;
876}
877
878#if defined(CONFIG_OF)
879static struct of_device_id pmc_ids[] = {
880 { .compatible = "atmel,at91rm9200-pmc" },
881 { .compatible = "atmel,at91sam9260-pmc" },
882 { .compatible = "atmel,at91sam9g45-pmc" },
883 { .compatible = "atmel,at91sam9n12-pmc" },
884 { .compatible = "atmel,at91sam9x5-pmc" },
885 { .compatible = "atmel,sama5d3-pmc" },
886 { /*sentinel*/ }
887};
888
889static struct of_device_id osc_ids[] = {
890 { .compatible = "atmel,osc" },
891 { /*sentinel*/ }
892};
893
894int __init at91_dt_clock_init(void)
895{
896 struct device_node *np;
897 u32 main_clock = 0;
898
899 np = of_find_matching_node(NULL, pmc_ids);
900 if (!np)
901 panic("unable to find compatible pmc node in dtb\n");
902
903 at91_pmc_base = of_iomap(np, 0);
904 if (!at91_pmc_base)
905 panic("unable to map pmc cpu registers\n");
906
907 of_node_put(np);
908
909 /* retrieve the freqency of fixed clocks from device tree */
910 np = of_find_matching_node(NULL, osc_ids);
911 if (np) {
912 u32 rate;
913 if (!of_property_read_u32(np, "clock-frequency", &rate))
914 main_clock = rate;
915 }
916
917 of_node_put(np);
918
919 return at91_pmc_init(main_clock);
920}
921#endif
922
923int __init at91_clock_init(unsigned long main_clock)
924{
925 at91_pmc_base = ioremap(AT91_PMC, 256);
926 if (!at91_pmc_base)
927 panic("Impossible to ioremap AT91_PMC 0x%x\n", AT91_PMC);
928
929 return at91_pmc_init(main_clock);
930}
931
932/*
933 * Several unused clocks may be active. Turn them off.
934 */
935static int __init at91_clock_reset(void)
936{
937 unsigned long pcdr = 0;
938 unsigned long pcdr1 = 0;
939 unsigned long scdr = 0;
940 struct clk *clk;
941
942 list_for_each_entry(clk, &clocks, node) {
943 if (clk->users > 0)
944 continue;
945
946 if (clk->mode == pmc_periph_mode) {
947 if (cpu_is_sama5d3()) {
948 u32 pmc_mask = 1 << (clk->pid % 32);
949
950 if (clk->pid > 31)
951 pcdr1 |= pmc_mask;
952 else
953 pcdr |= pmc_mask;
954 } else
955 pcdr |= clk->pmc_mask;
956 }
957
958 if (clk->mode == pmc_sys_mode)
959 scdr |= clk->pmc_mask;
960
961 pr_debug("Clocks: disable unused %s\n", clk->name);
962 }
963
964 at91_pmc_write(AT91_PMC_SCDR, scdr);
965 if (cpu_is_sama5d3())
966 at91_pmc_write(AT91_PMC_PCDR1, pcdr1);
967
968 return 0;
969}
970late_initcall(at91_clock_reset);
971
972void at91sam9_idle(void)
973{
974 at91_pmc_write(AT91_PMC_SCDR, AT91_PMC_PCK);
975 cpu_do_idle();
976}
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
37void __iomem *at91_pmc_base;
38EXPORT_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 || cpu_is_at91sam9n12())
63
64#define cpu_has_300M_plla() (cpu_is_at91sam9g10())
65
66#define cpu_has_pllb() (!(cpu_is_at91sam9rl() \
67 || cpu_is_at91sam9g45() \
68 || cpu_is_at91sam9x5() \
69 || cpu_is_at91sam9n12()))
70
71#define cpu_has_upll() (cpu_is_at91sam9g45() \
72 || cpu_is_at91sam9x5())
73
74/* USB host HS & FS */
75#define cpu_has_uhp() (!cpu_is_at91sam9rl())
76
77/* USB device FS only */
78#define cpu_has_udpfs() (!(cpu_is_at91sam9rl() \
79 || cpu_is_at91sam9g45() \
80 || cpu_is_at91sam9x5()))
81
82#define cpu_has_plladiv2() (cpu_is_at91sam9g45() \
83 || cpu_is_at91sam9x5() \
84 || cpu_is_at91sam9n12())
85
86#define cpu_has_mdiv3() (cpu_is_at91sam9g45() \
87 || cpu_is_at91sam9x5() \
88 || cpu_is_at91sam9n12())
89
90#define cpu_has_alt_prescaler() (cpu_is_at91sam9x5() \
91 || cpu_is_at91sam9n12())
92
93static LIST_HEAD(clocks);
94static DEFINE_SPINLOCK(clk_lock);
95
96static u32 at91_pllb_usb_init;
97
98/*
99 * Four primary clock sources: two crystal oscillators (32K, main), and
100 * two PLLs. PLLA usually runs the master clock; and PLLB must run at
101 * 48 MHz (unless no USB function clocks are needed). The main clock and
102 * both PLLs are turned off to run in "slow clock mode" (system suspend).
103 */
104static struct clk clk32k = {
105 .name = "clk32k",
106 .rate_hz = AT91_SLOW_CLOCK,
107 .users = 1, /* always on */
108 .id = 0,
109 .type = CLK_TYPE_PRIMARY,
110};
111static struct clk main_clk = {
112 .name = "main",
113 .pmc_mask = AT91_PMC_MOSCS, /* in PMC_SR */
114 .id = 1,
115 .type = CLK_TYPE_PRIMARY,
116};
117static struct clk plla = {
118 .name = "plla",
119 .parent = &main_clk,
120 .pmc_mask = AT91_PMC_LOCKA, /* in PMC_SR */
121 .id = 2,
122 .type = CLK_TYPE_PRIMARY | CLK_TYPE_PLL,
123};
124
125static void pllb_mode(struct clk *clk, int is_on)
126{
127 u32 value;
128
129 if (is_on) {
130 is_on = AT91_PMC_LOCKB;
131 value = at91_pllb_usb_init;
132 } else
133 value = 0;
134
135 // REVISIT: Add work-around for AT91RM9200 Errata #26 ?
136 at91_pmc_write(AT91_CKGR_PLLBR, value);
137
138 do {
139 cpu_relax();
140 } while ((at91_pmc_read(AT91_PMC_SR) & AT91_PMC_LOCKB) != is_on);
141}
142
143static struct clk pllb = {
144 .name = "pllb",
145 .parent = &main_clk,
146 .pmc_mask = AT91_PMC_LOCKB, /* in PMC_SR */
147 .mode = pllb_mode,
148 .id = 3,
149 .type = CLK_TYPE_PRIMARY | CLK_TYPE_PLL,
150};
151
152static void pmc_sys_mode(struct clk *clk, int is_on)
153{
154 if (is_on)
155 at91_pmc_write(AT91_PMC_SCER, clk->pmc_mask);
156 else
157 at91_pmc_write(AT91_PMC_SCDR, clk->pmc_mask);
158}
159
160static void pmc_uckr_mode(struct clk *clk, int is_on)
161{
162 unsigned int uckr = at91_pmc_read(AT91_CKGR_UCKR);
163
164 if (is_on) {
165 is_on = AT91_PMC_LOCKU;
166 at91_pmc_write(AT91_CKGR_UCKR, uckr | clk->pmc_mask);
167 } else
168 at91_pmc_write(AT91_CKGR_UCKR, uckr & ~(clk->pmc_mask));
169
170 do {
171 cpu_relax();
172 } while ((at91_pmc_read(AT91_PMC_SR) & AT91_PMC_LOCKU) != is_on);
173}
174
175/* USB function clocks (PLLB must be 48 MHz) */
176static struct clk udpck = {
177 .name = "udpck",
178 .parent = &pllb,
179 .mode = pmc_sys_mode,
180};
181struct clk utmi_clk = {
182 .name = "utmi_clk",
183 .parent = &main_clk,
184 .pmc_mask = AT91_PMC_UPLLEN, /* in CKGR_UCKR */
185 .mode = pmc_uckr_mode,
186 .type = CLK_TYPE_PLL,
187};
188static struct clk uhpck = {
189 .name = "uhpck",
190 /*.parent = ... we choose parent at runtime */
191 .mode = pmc_sys_mode,
192};
193
194
195/*
196 * The master clock is divided from the CPU clock (by 1-4). It's used for
197 * memory, interfaces to on-chip peripherals, the AIC, and sometimes more
198 * (e.g baud rate generation). It's sourced from one of the primary clocks.
199 */
200struct clk mck = {
201 .name = "mck",
202 .pmc_mask = AT91_PMC_MCKRDY, /* in PMC_SR */
203};
204
205static void pmc_periph_mode(struct clk *clk, int is_on)
206{
207 if (is_on)
208 at91_pmc_write(AT91_PMC_PCER, clk->pmc_mask);
209 else
210 at91_pmc_write(AT91_PMC_PCDR, clk->pmc_mask);
211}
212
213static struct clk __init *at91_css_to_clk(unsigned long css)
214{
215 switch (css) {
216 case AT91_PMC_CSS_SLOW:
217 return &clk32k;
218 case AT91_PMC_CSS_MAIN:
219 return &main_clk;
220 case AT91_PMC_CSS_PLLA:
221 return &plla;
222 case AT91_PMC_CSS_PLLB:
223 if (cpu_has_upll())
224 /* CSS_PLLB == CSS_UPLL */
225 return &utmi_clk;
226 else if (cpu_has_pllb())
227 return &pllb;
228 break;
229 /* alternate PMC: can use master clock */
230 case AT91_PMC_CSS_MASTER:
231 return &mck;
232 }
233
234 return NULL;
235}
236
237static int pmc_prescaler_divider(u32 reg)
238{
239 if (cpu_has_alt_prescaler()) {
240 return 1 << ((reg & AT91_PMC_ALT_PRES) >> PMC_ALT_PRES_OFFSET);
241 } else {
242 return 1 << ((reg & AT91_PMC_PRES) >> PMC_PRES_OFFSET);
243 }
244}
245
246static void __clk_enable(struct clk *clk)
247{
248 if (clk->parent)
249 __clk_enable(clk->parent);
250 if (clk->users++ == 0 && clk->mode)
251 clk->mode(clk, 1);
252}
253
254int clk_enable(struct clk *clk)
255{
256 unsigned long flags;
257
258 spin_lock_irqsave(&clk_lock, flags);
259 __clk_enable(clk);
260 spin_unlock_irqrestore(&clk_lock, flags);
261 return 0;
262}
263EXPORT_SYMBOL(clk_enable);
264
265static void __clk_disable(struct clk *clk)
266{
267 BUG_ON(clk->users == 0);
268 if (--clk->users == 0 && clk->mode)
269 clk->mode(clk, 0);
270 if (clk->parent)
271 __clk_disable(clk->parent);
272}
273
274void clk_disable(struct clk *clk)
275{
276 unsigned long flags;
277
278 spin_lock_irqsave(&clk_lock, flags);
279 __clk_disable(clk);
280 spin_unlock_irqrestore(&clk_lock, flags);
281}
282EXPORT_SYMBOL(clk_disable);
283
284unsigned long clk_get_rate(struct clk *clk)
285{
286 unsigned long flags;
287 unsigned long rate;
288
289 spin_lock_irqsave(&clk_lock, flags);
290 for (;;) {
291 rate = clk->rate_hz;
292 if (rate || !clk->parent)
293 break;
294 clk = clk->parent;
295 }
296 spin_unlock_irqrestore(&clk_lock, flags);
297 return rate;
298}
299EXPORT_SYMBOL(clk_get_rate);
300
301/*------------------------------------------------------------------------*/
302
303#ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
304
305/*
306 * For now, only the programmable clocks support reparenting (MCK could
307 * do this too, with care) or rate changing (the PLLs could do this too,
308 * ditto MCK but that's more for cpufreq). Drivers may reparent to get
309 * a better rate match; we don't.
310 */
311
312long clk_round_rate(struct clk *clk, unsigned long rate)
313{
314 unsigned long flags;
315 unsigned prescale;
316 unsigned long actual;
317 unsigned long prev = ULONG_MAX;
318
319 if (!clk_is_programmable(clk))
320 return -EINVAL;
321 spin_lock_irqsave(&clk_lock, flags);
322
323 actual = clk->parent->rate_hz;
324 for (prescale = 0; prescale < 7; prescale++) {
325 if (actual > rate)
326 prev = actual;
327
328 if (actual && actual <= rate) {
329 if ((prev - rate) < (rate - actual)) {
330 actual = prev;
331 prescale--;
332 }
333 break;
334 }
335 actual >>= 1;
336 }
337
338 spin_unlock_irqrestore(&clk_lock, flags);
339 return (prescale < 7) ? actual : -ENOENT;
340}
341EXPORT_SYMBOL(clk_round_rate);
342
343int clk_set_rate(struct clk *clk, unsigned long rate)
344{
345 unsigned long flags;
346 unsigned prescale;
347 unsigned long prescale_offset, css_mask;
348 unsigned long actual;
349
350 if (!clk_is_programmable(clk))
351 return -EINVAL;
352 if (clk->users)
353 return -EBUSY;
354
355 if (cpu_has_alt_prescaler()) {
356 prescale_offset = PMC_ALT_PRES_OFFSET;
357 css_mask = AT91_PMC_ALT_PCKR_CSS;
358 } else {
359 prescale_offset = PMC_PRES_OFFSET;
360 css_mask = AT91_PMC_CSS;
361 }
362
363 spin_lock_irqsave(&clk_lock, flags);
364
365 actual = clk->parent->rate_hz;
366 for (prescale = 0; prescale < 7; prescale++) {
367 if (actual && actual <= rate) {
368 u32 pckr;
369
370 pckr = at91_pmc_read(AT91_PMC_PCKR(clk->id));
371 pckr &= css_mask; /* keep clock selection */
372 pckr |= prescale << prescale_offset;
373 at91_pmc_write(AT91_PMC_PCKR(clk->id), pckr);
374 clk->rate_hz = actual;
375 break;
376 }
377 actual >>= 1;
378 }
379
380 spin_unlock_irqrestore(&clk_lock, flags);
381 return (prescale < 7) ? actual : -ENOENT;
382}
383EXPORT_SYMBOL(clk_set_rate);
384
385struct clk *clk_get_parent(struct clk *clk)
386{
387 return clk->parent;
388}
389EXPORT_SYMBOL(clk_get_parent);
390
391int clk_set_parent(struct clk *clk, struct clk *parent)
392{
393 unsigned long flags;
394
395 if (clk->users)
396 return -EBUSY;
397 if (!clk_is_primary(parent) || !clk_is_programmable(clk))
398 return -EINVAL;
399
400 if (cpu_is_at91sam9rl() && parent->id == AT91_PMC_CSS_PLLB)
401 return -EINVAL;
402
403 spin_lock_irqsave(&clk_lock, flags);
404
405 clk->rate_hz = parent->rate_hz;
406 clk->parent = parent;
407 at91_pmc_write(AT91_PMC_PCKR(clk->id), parent->id);
408
409 spin_unlock_irqrestore(&clk_lock, flags);
410 return 0;
411}
412EXPORT_SYMBOL(clk_set_parent);
413
414/* establish PCK0..PCKN parentage and rate */
415static void __init init_programmable_clock(struct clk *clk)
416{
417 struct clk *parent;
418 u32 pckr;
419 unsigned int css_mask;
420
421 if (cpu_has_alt_prescaler())
422 css_mask = AT91_PMC_ALT_PCKR_CSS;
423 else
424 css_mask = AT91_PMC_CSS;
425
426 pckr = at91_pmc_read(AT91_PMC_PCKR(clk->id));
427 parent = at91_css_to_clk(pckr & css_mask);
428 clk->parent = parent;
429 clk->rate_hz = parent->rate_hz / pmc_prescaler_divider(pckr);
430}
431
432#endif /* CONFIG_AT91_PROGRAMMABLE_CLOCKS */
433
434/*------------------------------------------------------------------------*/
435
436#ifdef CONFIG_DEBUG_FS
437
438static int at91_clk_show(struct seq_file *s, void *unused)
439{
440 u32 scsr, pcsr, uckr = 0, sr;
441 struct clk *clk;
442
443 scsr = at91_pmc_read(AT91_PMC_SCSR);
444 pcsr = at91_pmc_read(AT91_PMC_PCSR);
445 sr = at91_pmc_read(AT91_PMC_SR);
446 seq_printf(s, "SCSR = %8x\n", scsr);
447 seq_printf(s, "PCSR = %8x\n", pcsr);
448 seq_printf(s, "MOR = %8x\n", at91_pmc_read(AT91_CKGR_MOR));
449 seq_printf(s, "MCFR = %8x\n", at91_pmc_read(AT91_CKGR_MCFR));
450 seq_printf(s, "PLLA = %8x\n", at91_pmc_read(AT91_CKGR_PLLAR));
451 if (cpu_has_pllb())
452 seq_printf(s, "PLLB = %8x\n", at91_pmc_read(AT91_CKGR_PLLBR));
453 if (cpu_has_utmi()) {
454 uckr = at91_pmc_read(AT91_CKGR_UCKR);
455 seq_printf(s, "UCKR = %8x\n", uckr);
456 }
457 seq_printf(s, "MCKR = %8x\n", at91_pmc_read(AT91_PMC_MCKR));
458 if (cpu_has_upll())
459 seq_printf(s, "USB = %8x\n", at91_pmc_read(AT91_PMC_USB));
460 seq_printf(s, "SR = %8x\n", sr);
461
462 seq_printf(s, "\n");
463
464 list_for_each_entry(clk, &clocks, node) {
465 char *state;
466
467 if (clk->mode == pmc_sys_mode)
468 state = (scsr & clk->pmc_mask) ? "on" : "off";
469 else if (clk->mode == pmc_periph_mode)
470 state = (pcsr & clk->pmc_mask) ? "on" : "off";
471 else if (clk->mode == pmc_uckr_mode)
472 state = (uckr & clk->pmc_mask) ? "on" : "off";
473 else if (clk->pmc_mask)
474 state = (sr & clk->pmc_mask) ? "on" : "off";
475 else if (clk == &clk32k || clk == &main_clk)
476 state = "on";
477 else
478 state = "";
479
480 seq_printf(s, "%-10s users=%2d %-3s %9ld Hz %s\n",
481 clk->name, clk->users, state, clk_get_rate(clk),
482 clk->parent ? clk->parent->name : "");
483 }
484 return 0;
485}
486
487static int at91_clk_open(struct inode *inode, struct file *file)
488{
489 return single_open(file, at91_clk_show, NULL);
490}
491
492static const struct file_operations at91_clk_operations = {
493 .open = at91_clk_open,
494 .read = seq_read,
495 .llseek = seq_lseek,
496 .release = single_release,
497};
498
499static int __init at91_clk_debugfs_init(void)
500{
501 /* /sys/kernel/debug/at91_clk */
502 (void) debugfs_create_file("at91_clk", S_IFREG | S_IRUGO, NULL, NULL, &at91_clk_operations);
503
504 return 0;
505}
506postcore_initcall(at91_clk_debugfs_init);
507
508#endif
509
510/*------------------------------------------------------------------------*/
511
512/* Register a new clock */
513static void __init at91_clk_add(struct clk *clk)
514{
515 list_add_tail(&clk->node, &clocks);
516
517 clk->cl.con_id = clk->name;
518 clk->cl.clk = clk;
519 clkdev_add(&clk->cl);
520}
521
522int __init clk_register(struct clk *clk)
523{
524 if (clk_is_peripheral(clk)) {
525 if (!clk->parent)
526 clk->parent = &mck;
527 clk->mode = pmc_periph_mode;
528 }
529 else if (clk_is_sys(clk)) {
530 clk->parent = &mck;
531 clk->mode = pmc_sys_mode;
532 }
533#ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
534 else if (clk_is_programmable(clk)) {
535 clk->mode = pmc_sys_mode;
536 init_programmable_clock(clk);
537 }
538#endif
539
540 at91_clk_add(clk);
541
542 return 0;
543}
544
545/*------------------------------------------------------------------------*/
546
547static u32 __init at91_pll_rate(struct clk *pll, u32 freq, u32 reg)
548{
549 unsigned mul, div;
550
551 div = reg & 0xff;
552 mul = (reg >> 16) & 0x7ff;
553 if (div && mul) {
554 freq /= div;
555 freq *= mul + 1;
556 } else
557 freq = 0;
558
559 return freq;
560}
561
562static u32 __init at91_usb_rate(struct clk *pll, u32 freq, u32 reg)
563{
564 if (pll == &pllb && (reg & AT91_PMC_USB96M))
565 return freq / 2;
566 else
567 return freq;
568}
569
570static unsigned __init at91_pll_calc(unsigned main_freq, unsigned out_freq)
571{
572 unsigned i, div = 0, mul = 0, diff = 1 << 30;
573 unsigned ret = (out_freq > 155000000) ? 0xbe00 : 0x3e00;
574
575 /* PLL output max 240 MHz (or 180 MHz per errata) */
576 if (out_freq > 240000000)
577 goto fail;
578
579 for (i = 1; i < 256; i++) {
580 int diff1;
581 unsigned input, mul1;
582
583 /*
584 * PLL input between 1MHz and 32MHz per spec, but lower
585 * frequences seem necessary in some cases so allow 100K.
586 * Warning: some newer products need 2MHz min.
587 */
588 input = main_freq / i;
589 if (cpu_is_at91sam9g20() && input < 2000000)
590 continue;
591 if (input < 100000)
592 continue;
593 if (input > 32000000)
594 continue;
595
596 mul1 = out_freq / input;
597 if (cpu_is_at91sam9g20() && mul > 63)
598 continue;
599 if (mul1 > 2048)
600 continue;
601 if (mul1 < 2)
602 goto fail;
603
604 diff1 = out_freq - input * mul1;
605 if (diff1 < 0)
606 diff1 = -diff1;
607 if (diff > diff1) {
608 diff = diff1;
609 div = i;
610 mul = mul1;
611 if (diff == 0)
612 break;
613 }
614 }
615 if (i == 256 && diff > (out_freq >> 5))
616 goto fail;
617 return ret | ((mul - 1) << 16) | div;
618fail:
619 return 0;
620}
621
622static struct clk *const standard_pmc_clocks[] __initdata = {
623 /* four primary clocks */
624 &clk32k,
625 &main_clk,
626 &plla,
627
628 /* MCK */
629 &mck
630};
631
632/* PLLB generated USB full speed clock init */
633static void __init at91_pllb_usbfs_clock_init(unsigned long main_clock)
634{
635 /*
636 * USB clock init: choose 48 MHz PLLB value,
637 * disable 48MHz clock during usb peripheral suspend.
638 *
639 * REVISIT: assumes MCK doesn't derive from PLLB!
640 */
641 uhpck.parent = &pllb;
642
643 at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2) | AT91_PMC_USB96M;
644 pllb.rate_hz = at91_pll_rate(&pllb, main_clock, at91_pllb_usb_init);
645 if (cpu_is_at91rm9200()) {
646 uhpck.pmc_mask = AT91RM9200_PMC_UHP;
647 udpck.pmc_mask = AT91RM9200_PMC_UDP;
648 at91_pmc_write(AT91_PMC_SCER, AT91RM9200_PMC_MCKUDP);
649 } else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() ||
650 cpu_is_at91sam9263() || cpu_is_at91sam9g20() ||
651 cpu_is_at91sam9g10()) {
652 uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
653 udpck.pmc_mask = AT91SAM926x_PMC_UDP;
654 }
655 at91_pmc_write(AT91_CKGR_PLLBR, 0);
656
657 udpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init);
658 uhpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init);
659}
660
661/* UPLL generated USB full speed clock init */
662static void __init at91_upll_usbfs_clock_init(unsigned long main_clock)
663{
664 /*
665 * USB clock init: choose 480 MHz from UPLL,
666 */
667 unsigned int usbr = AT91_PMC_USBS_UPLL;
668
669 /* Setup divider by 10 to reach 48 MHz */
670 usbr |= ((10 - 1) << 8) & AT91_PMC_OHCIUSBDIV;
671
672 at91_pmc_write(AT91_PMC_USB, usbr);
673
674 /* Now set uhpck values */
675 uhpck.parent = &utmi_clk;
676 uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
677 uhpck.rate_hz = utmi_clk.rate_hz;
678 uhpck.rate_hz /= 1 + ((at91_pmc_read(AT91_PMC_USB) & AT91_PMC_OHCIUSBDIV) >> 8);
679}
680
681static int __init at91_pmc_init(unsigned long main_clock)
682{
683 unsigned tmp, freq, mckr;
684 int i;
685 int pll_overclock = false;
686
687 /*
688 * When the bootloader initialized the main oscillator correctly,
689 * there's no problem using the cycle counter. But if it didn't,
690 * or when using oscillator bypass mode, we must be told the speed
691 * of the main clock.
692 */
693 if (!main_clock) {
694 do {
695 tmp = at91_pmc_read(AT91_CKGR_MCFR);
696 } while (!(tmp & AT91_PMC_MAINRDY));
697 main_clock = (tmp & AT91_PMC_MAINF) * (AT91_SLOW_CLOCK / 16);
698 }
699 main_clk.rate_hz = main_clock;
700
701 /* report if PLLA is more than mildly overclocked */
702 plla.rate_hz = at91_pll_rate(&plla, main_clock, at91_pmc_read(AT91_CKGR_PLLAR));
703 if (cpu_has_300M_plla()) {
704 if (plla.rate_hz > 300000000)
705 pll_overclock = true;
706 } else if (cpu_has_800M_plla()) {
707 if (plla.rate_hz > 800000000)
708 pll_overclock = true;
709 } else {
710 if (plla.rate_hz > 209000000)
711 pll_overclock = true;
712 }
713 if (pll_overclock)
714 pr_info("Clocks: PLLA overclocked, %ld MHz\n", plla.rate_hz / 1000000);
715
716 if (cpu_has_plladiv2()) {
717 mckr = at91_pmc_read(AT91_PMC_MCKR);
718 plla.rate_hz /= (1 << ((mckr & AT91_PMC_PLLADIV2) >> 12)); /* plla divisor by 2 */
719 }
720
721 if (!cpu_has_pllb() && cpu_has_upll()) {
722 /* setup UTMI clock as the fourth primary clock
723 * (instead of pllb) */
724 utmi_clk.type |= CLK_TYPE_PRIMARY;
725 utmi_clk.id = 3;
726 }
727
728
729 /*
730 * USB HS clock init
731 */
732 if (cpu_has_utmi()) {
733 /*
734 * multiplier is hard-wired to 40
735 * (obtain the USB High Speed 480 MHz when input is 12 MHz)
736 */
737 utmi_clk.rate_hz = 40 * utmi_clk.parent->rate_hz;
738
739 /* UTMI bias and PLL are managed at the same time */
740 if (cpu_has_upll())
741 utmi_clk.pmc_mask |= AT91_PMC_BIASEN;
742 }
743
744 /*
745 * USB FS clock init
746 */
747 if (cpu_has_pllb())
748 at91_pllb_usbfs_clock_init(main_clock);
749 if (cpu_has_upll())
750 /* assumes that we choose UPLL for USB and not PLLA */
751 at91_upll_usbfs_clock_init(main_clock);
752
753 /*
754 * MCK and CPU derive from one of those primary clocks.
755 * For now, assume this parentage won't change.
756 */
757 mckr = at91_pmc_read(AT91_PMC_MCKR);
758 mck.parent = at91_css_to_clk(mckr & AT91_PMC_CSS);
759 freq = mck.parent->rate_hz;
760 freq /= pmc_prescaler_divider(mckr); /* prescale */
761 if (cpu_is_at91rm9200()) {
762 mck.rate_hz = freq / (1 + ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
763 } else if (cpu_is_at91sam9g20()) {
764 mck.rate_hz = (mckr & AT91_PMC_MDIV) ?
765 freq / ((mckr & AT91_PMC_MDIV) >> 7) : freq; /* mdiv ; (x >> 7) = ((x >> 8) * 2) */
766 if (mckr & AT91_PMC_PDIV)
767 freq /= 2; /* processor clock division */
768 } else if (cpu_has_mdiv3()) {
769 mck.rate_hz = (mckr & AT91_PMC_MDIV) == AT91SAM9_PMC_MDIV_3 ?
770 freq / 3 : freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
771 } else {
772 mck.rate_hz = freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
773 }
774
775 if (cpu_has_alt_prescaler()) {
776 /* Programmable clocks can use MCK */
777 mck.type |= CLK_TYPE_PRIMARY;
778 mck.id = 4;
779 }
780
781 /* Register the PMC's standard clocks */
782 for (i = 0; i < ARRAY_SIZE(standard_pmc_clocks); i++)
783 at91_clk_add(standard_pmc_clocks[i]);
784
785 if (cpu_has_pllb())
786 at91_clk_add(&pllb);
787
788 if (cpu_has_uhp())
789 at91_clk_add(&uhpck);
790
791 if (cpu_has_udpfs())
792 at91_clk_add(&udpck);
793
794 if (cpu_has_utmi())
795 at91_clk_add(&utmi_clk);
796
797 /* MCK and CPU clock are "always on" */
798 clk_enable(&mck);
799
800 printk("Clocks: CPU %u MHz, master %u MHz, main %u.%03u MHz\n",
801 freq / 1000000, (unsigned) mck.rate_hz / 1000000,
802 (unsigned) main_clock / 1000000,
803 ((unsigned) main_clock % 1000000) / 1000);
804
805 return 0;
806}
807
808#if defined(CONFIG_OF)
809static struct of_device_id pmc_ids[] = {
810 { .compatible = "atmel,at91rm9200-pmc" },
811 { /*sentinel*/ }
812};
813
814static struct of_device_id osc_ids[] = {
815 { .compatible = "atmel,osc" },
816 { /*sentinel*/ }
817};
818
819int __init at91_dt_clock_init(void)
820{
821 struct device_node *np;
822 u32 main_clock = 0;
823
824 np = of_find_matching_node(NULL, pmc_ids);
825 if (!np)
826 panic("unable to find compatible pmc node in dtb\n");
827
828 at91_pmc_base = of_iomap(np, 0);
829 if (!at91_pmc_base)
830 panic("unable to map pmc cpu registers\n");
831
832 of_node_put(np);
833
834 /* retrieve the freqency of fixed clocks from device tree */
835 np = of_find_matching_node(NULL, osc_ids);
836 if (np) {
837 u32 rate;
838 if (!of_property_read_u32(np, "clock-frequency", &rate))
839 main_clock = rate;
840 }
841
842 of_node_put(np);
843
844 return at91_pmc_init(main_clock);
845}
846#endif
847
848int __init at91_clock_init(unsigned long main_clock)
849{
850 at91_pmc_base = ioremap(AT91_PMC, 256);
851 if (!at91_pmc_base)
852 panic("Impossible to ioremap AT91_PMC 0x%x\n", AT91_PMC);
853
854 return at91_pmc_init(main_clock);
855}
856
857/*
858 * Several unused clocks may be active. Turn them off.
859 */
860static int __init at91_clock_reset(void)
861{
862 unsigned long pcdr = 0;
863 unsigned long scdr = 0;
864 struct clk *clk;
865
866 list_for_each_entry(clk, &clocks, node) {
867 if (clk->users > 0)
868 continue;
869
870 if (clk->mode == pmc_periph_mode)
871 pcdr |= clk->pmc_mask;
872
873 if (clk->mode == pmc_sys_mode)
874 scdr |= clk->pmc_mask;
875
876 pr_debug("Clocks: disable unused %s\n", clk->name);
877 }
878
879 at91_pmc_write(AT91_PMC_PCDR, pcdr);
880 at91_pmc_write(AT91_PMC_SCDR, scdr);
881
882 return 0;
883}
884late_initcall(at91_clock_reset);
885
886void at91sam9_idle(void)
887{
888 at91_pmc_write(AT91_PMC_SCDR, AT91_PMC_PCK);
889 cpu_do_idle();
890}