2 * linux/arch/arm/mach-at91/clock.c
4 * Copyright (C) 2005 David Brownell
5 * Copyright (C) 2005 Ivan Kokshaysky
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.
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/init.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>
26 #include <linux/of_address.h>
28 #include <mach/hardware.h>
29 #include <mach/at91_pmc.h>
32 #include <asm/proc-fns.h>
37 void __iomem
*at91_pmc_base
;
40 * There's a lot more which can be done with clocks, including cpufreq
41 * integration, slow clock mode support (for system suspend), letting
42 * PLLB be used at other rates (on boards that don't need USB), etc.
45 #define clk_is_primary(x) ((x)->type & CLK_TYPE_PRIMARY)
46 #define clk_is_programmable(x) ((x)->type & CLK_TYPE_PROGRAMMABLE)
47 #define clk_is_peripheral(x) ((x)->type & CLK_TYPE_PERIPHERAL)
48 #define clk_is_sys(x) ((x)->type & CLK_TYPE_SYSTEM)
52 * Chips have some kind of clocks : group them by functionality
54 #define cpu_has_utmi() ( cpu_is_at91sam9rl() \
55 || cpu_is_at91sam9g45() \
56 || cpu_is_at91sam9x5())
58 #define cpu_has_800M_plla() ( cpu_is_at91sam9g20() \
59 || cpu_is_at91sam9g45() \
60 || cpu_is_at91sam9x5() \
61 || cpu_is_at91sam9n12())
63 #define cpu_has_300M_plla() (cpu_is_at91sam9g10())
65 #define cpu_has_pllb() (!(cpu_is_at91sam9rl() \
66 || cpu_is_at91sam9g45() \
67 || cpu_is_at91sam9x5() \
68 || cpu_is_at91sam9n12()))
70 #define cpu_has_upll() (cpu_is_at91sam9g45() \
71 || cpu_is_at91sam9x5())
73 /* USB host HS & FS */
74 #define cpu_has_uhp() (!cpu_is_at91sam9rl())
76 /* USB device FS only */
77 #define cpu_has_udpfs() (!(cpu_is_at91sam9rl() \
78 || cpu_is_at91sam9g45() \
79 || cpu_is_at91sam9x5()))
81 #define cpu_has_plladiv2() (cpu_is_at91sam9g45() \
82 || cpu_is_at91sam9x5() \
83 || cpu_is_at91sam9n12())
85 #define cpu_has_mdiv3() (cpu_is_at91sam9g45() \
86 || cpu_is_at91sam9x5() \
87 || cpu_is_at91sam9n12())
89 #define cpu_has_alt_prescaler() (cpu_is_at91sam9x5() \
90 || cpu_is_at91sam9n12())
92 static LIST_HEAD(clocks
);
93 static DEFINE_SPINLOCK(clk_lock
);
95 static u32 at91_pllb_usb_init
;
98 * Four primary clock sources: two crystal oscillators (32K, main), and
99 * two PLLs. PLLA usually runs the master clock; and PLLB must run at
100 * 48 MHz (unless no USB function clocks are needed). The main clock and
101 * both PLLs are turned off to run in "slow clock mode" (system suspend).
103 static struct clk clk32k
= {
105 .rate_hz
= AT91_SLOW_CLOCK
,
106 .users
= 1, /* always on */
108 .type
= CLK_TYPE_PRIMARY
,
110 static struct clk main_clk
= {
112 .pmc_mask
= AT91_PMC_MOSCS
, /* in PMC_SR */
114 .type
= CLK_TYPE_PRIMARY
,
116 static struct clk plla
= {
119 .pmc_mask
= AT91_PMC_LOCKA
, /* in PMC_SR */
121 .type
= CLK_TYPE_PRIMARY
| CLK_TYPE_PLL
,
124 static void pllb_mode(struct clk
*clk
, int is_on
)
129 is_on
= AT91_PMC_LOCKB
;
130 value
= at91_pllb_usb_init
;
134 // REVISIT: Add work-around for AT91RM9200 Errata #26 ?
135 at91_pmc_write(AT91_CKGR_PLLBR
, value
);
139 } while ((at91_pmc_read(AT91_PMC_SR
) & AT91_PMC_LOCKB
) != is_on
);
142 static struct clk pllb
= {
145 .pmc_mask
= AT91_PMC_LOCKB
, /* in PMC_SR */
148 .type
= CLK_TYPE_PRIMARY
| CLK_TYPE_PLL
,
151 static void pmc_sys_mode(struct clk
*clk
, int is_on
)
154 at91_pmc_write(AT91_PMC_SCER
, clk
->pmc_mask
);
156 at91_pmc_write(AT91_PMC_SCDR
, clk
->pmc_mask
);
159 static void pmc_uckr_mode(struct clk
*clk
, int is_on
)
161 unsigned int uckr
= at91_pmc_read(AT91_CKGR_UCKR
);
164 is_on
= AT91_PMC_LOCKU
;
165 at91_pmc_write(AT91_CKGR_UCKR
, uckr
| clk
->pmc_mask
);
167 at91_pmc_write(AT91_CKGR_UCKR
, uckr
& ~(clk
->pmc_mask
));
171 } while ((at91_pmc_read(AT91_PMC_SR
) & AT91_PMC_LOCKU
) != is_on
);
174 /* USB function clocks (PLLB must be 48 MHz) */
175 static struct clk udpck
= {
178 .mode
= pmc_sys_mode
,
180 struct clk utmi_clk
= {
183 .pmc_mask
= AT91_PMC_UPLLEN
, /* in CKGR_UCKR */
184 .mode
= pmc_uckr_mode
,
185 .type
= CLK_TYPE_PLL
,
187 static struct clk uhpck
= {
189 /*.parent = ... we choose parent at runtime */
190 .mode
= pmc_sys_mode
,
195 * The master clock is divided from the CPU clock (by 1-4). It's used for
196 * memory, interfaces to on-chip peripherals, the AIC, and sometimes more
197 * (e.g baud rate generation). It's sourced from one of the primary clocks.
201 .pmc_mask
= AT91_PMC_MCKRDY
, /* in PMC_SR */
204 static void pmc_periph_mode(struct clk
*clk
, int is_on
)
207 at91_pmc_write(AT91_PMC_PCER
, clk
->pmc_mask
);
209 at91_pmc_write(AT91_PMC_PCDR
, clk
->pmc_mask
);
212 static struct clk __init
*at91_css_to_clk(unsigned long css
)
215 case AT91_PMC_CSS_SLOW
:
217 case AT91_PMC_CSS_MAIN
:
219 case AT91_PMC_CSS_PLLA
:
221 case AT91_PMC_CSS_PLLB
:
223 /* CSS_PLLB == CSS_UPLL */
225 else if (cpu_has_pllb())
228 /* alternate PMC: can use master clock */
229 case AT91_PMC_CSS_MASTER
:
236 static int pmc_prescaler_divider(u32 reg
)
238 if (cpu_has_alt_prescaler()) {
239 return 1 << ((reg
& AT91_PMC_ALT_PRES
) >> PMC_ALT_PRES_OFFSET
);
241 return 1 << ((reg
& AT91_PMC_PRES
) >> PMC_PRES_OFFSET
);
245 static void __clk_enable(struct clk
*clk
)
248 __clk_enable(clk
->parent
);
249 if (clk
->users
++ == 0 && clk
->mode
)
253 int clk_enable(struct clk
*clk
)
257 spin_lock_irqsave(&clk_lock
, flags
);
259 spin_unlock_irqrestore(&clk_lock
, flags
);
262 EXPORT_SYMBOL(clk_enable
);
264 static void __clk_disable(struct clk
*clk
)
266 BUG_ON(clk
->users
== 0);
267 if (--clk
->users
== 0 && clk
->mode
)
270 __clk_disable(clk
->parent
);
273 void clk_disable(struct clk
*clk
)
277 spin_lock_irqsave(&clk_lock
, flags
);
279 spin_unlock_irqrestore(&clk_lock
, flags
);
281 EXPORT_SYMBOL(clk_disable
);
283 unsigned long clk_get_rate(struct clk
*clk
)
288 spin_lock_irqsave(&clk_lock
, flags
);
291 if (rate
|| !clk
->parent
)
295 spin_unlock_irqrestore(&clk_lock
, flags
);
298 EXPORT_SYMBOL(clk_get_rate
);
300 /*------------------------------------------------------------------------*/
302 #ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
305 * For now, only the programmable clocks support reparenting (MCK could
306 * do this too, with care) or rate changing (the PLLs could do this too,
307 * ditto MCK but that's more for cpufreq). Drivers may reparent to get
308 * a better rate match; we don't.
311 long clk_round_rate(struct clk
*clk
, unsigned long rate
)
315 unsigned long actual
;
316 unsigned long prev
= ULONG_MAX
;
318 if (!clk_is_programmable(clk
))
320 spin_lock_irqsave(&clk_lock
, flags
);
322 actual
= clk
->parent
->rate_hz
;
323 for (prescale
= 0; prescale
< 7; prescale
++) {
327 if (actual
&& actual
<= rate
) {
328 if ((prev
- rate
) < (rate
- actual
)) {
337 spin_unlock_irqrestore(&clk_lock
, flags
);
338 return (prescale
< 7) ? actual
: -ENOENT
;
340 EXPORT_SYMBOL(clk_round_rate
);
342 int clk_set_rate(struct clk
*clk
, unsigned long rate
)
346 unsigned long prescale_offset
, css_mask
;
347 unsigned long actual
;
349 if (!clk_is_programmable(clk
))
354 if (cpu_has_alt_prescaler()) {
355 prescale_offset
= PMC_ALT_PRES_OFFSET
;
356 css_mask
= AT91_PMC_ALT_PCKR_CSS
;
358 prescale_offset
= PMC_PRES_OFFSET
;
359 css_mask
= AT91_PMC_CSS
;
362 spin_lock_irqsave(&clk_lock
, flags
);
364 actual
= clk
->parent
->rate_hz
;
365 for (prescale
= 0; prescale
< 7; prescale
++) {
366 if (actual
&& actual
<= rate
) {
369 pckr
= at91_pmc_read(AT91_PMC_PCKR(clk
->id
));
370 pckr
&= css_mask
; /* keep clock selection */
371 pckr
|= prescale
<< prescale_offset
;
372 at91_pmc_write(AT91_PMC_PCKR(clk
->id
), pckr
);
373 clk
->rate_hz
= actual
;
379 spin_unlock_irqrestore(&clk_lock
, flags
);
380 return (prescale
< 7) ? actual
: -ENOENT
;
382 EXPORT_SYMBOL(clk_set_rate
);
384 struct clk
*clk_get_parent(struct clk
*clk
)
388 EXPORT_SYMBOL(clk_get_parent
);
390 int clk_set_parent(struct clk
*clk
, struct clk
*parent
)
396 if (!clk_is_primary(parent
) || !clk_is_programmable(clk
))
399 if (cpu_is_at91sam9rl() && parent
->id
== AT91_PMC_CSS_PLLB
)
402 spin_lock_irqsave(&clk_lock
, flags
);
404 clk
->rate_hz
= parent
->rate_hz
;
405 clk
->parent
= parent
;
406 at91_pmc_write(AT91_PMC_PCKR(clk
->id
), parent
->id
);
408 spin_unlock_irqrestore(&clk_lock
, flags
);
411 EXPORT_SYMBOL(clk_set_parent
);
413 /* establish PCK0..PCKN parentage and rate */
414 static void __init
init_programmable_clock(struct clk
*clk
)
418 unsigned int css_mask
;
420 if (cpu_has_alt_prescaler())
421 css_mask
= AT91_PMC_ALT_PCKR_CSS
;
423 css_mask
= AT91_PMC_CSS
;
425 pckr
= at91_pmc_read(AT91_PMC_PCKR(clk
->id
));
426 parent
= at91_css_to_clk(pckr
& css_mask
);
427 clk
->parent
= parent
;
428 clk
->rate_hz
= parent
->rate_hz
/ pmc_prescaler_divider(pckr
);
431 #endif /* CONFIG_AT91_PROGRAMMABLE_CLOCKS */
433 /*------------------------------------------------------------------------*/
435 #ifdef CONFIG_DEBUG_FS
437 static int at91_clk_show(struct seq_file
*s
, void *unused
)
439 u32 scsr
, pcsr
, uckr
= 0, sr
;
442 scsr
= at91_pmc_read(AT91_PMC_SCSR
);
443 pcsr
= at91_pmc_read(AT91_PMC_PCSR
);
444 sr
= at91_pmc_read(AT91_PMC_SR
);
445 seq_printf(s
, "SCSR = %8x\n", scsr
);
446 seq_printf(s
, "PCSR = %8x\n", pcsr
);
447 seq_printf(s
, "MOR = %8x\n", at91_pmc_read(AT91_CKGR_MOR
));
448 seq_printf(s
, "MCFR = %8x\n", at91_pmc_read(AT91_CKGR_MCFR
));
449 seq_printf(s
, "PLLA = %8x\n", at91_pmc_read(AT91_CKGR_PLLAR
));
451 seq_printf(s
, "PLLB = %8x\n", at91_pmc_read(AT91_CKGR_PLLBR
));
452 if (cpu_has_utmi()) {
453 uckr
= at91_pmc_read(AT91_CKGR_UCKR
);
454 seq_printf(s
, "UCKR = %8x\n", uckr
);
456 seq_printf(s
, "MCKR = %8x\n", at91_pmc_read(AT91_PMC_MCKR
));
458 seq_printf(s
, "USB = %8x\n", at91_pmc_read(AT91_PMC_USB
));
459 seq_printf(s
, "SR = %8x\n", sr
);
463 list_for_each_entry(clk
, &clocks
, node
) {
466 if (clk
->mode
== pmc_sys_mode
)
467 state
= (scsr
& clk
->pmc_mask
) ? "on" : "off";
468 else if (clk
->mode
== pmc_periph_mode
)
469 state
= (pcsr
& clk
->pmc_mask
) ? "on" : "off";
470 else if (clk
->mode
== pmc_uckr_mode
)
471 state
= (uckr
& clk
->pmc_mask
) ? "on" : "off";
472 else if (clk
->pmc_mask
)
473 state
= (sr
& clk
->pmc_mask
) ? "on" : "off";
474 else if (clk
== &clk32k
|| clk
== &main_clk
)
479 seq_printf(s
, "%-10s users=%2d %-3s %9ld Hz %s\n",
480 clk
->name
, clk
->users
, state
, clk_get_rate(clk
),
481 clk
->parent
? clk
->parent
->name
: "");
486 static int at91_clk_open(struct inode
*inode
, struct file
*file
)
488 return single_open(file
, at91_clk_show
, NULL
);
491 static const struct file_operations at91_clk_operations
= {
492 .open
= at91_clk_open
,
495 .release
= single_release
,
498 static int __init
at91_clk_debugfs_init(void)
500 /* /sys/kernel/debug/at91_clk */
501 (void) debugfs_create_file("at91_clk", S_IFREG
| S_IRUGO
, NULL
, NULL
, &at91_clk_operations
);
505 postcore_initcall(at91_clk_debugfs_init
);
509 /*------------------------------------------------------------------------*/
511 /* Register a new clock */
512 static void __init
at91_clk_add(struct clk
*clk
)
514 list_add_tail(&clk
->node
, &clocks
);
516 clk
->cl
.con_id
= clk
->name
;
518 clkdev_add(&clk
->cl
);
521 int __init
clk_register(struct clk
*clk
)
523 if (clk_is_peripheral(clk
)) {
526 clk
->mode
= pmc_periph_mode
;
528 else if (clk_is_sys(clk
)) {
530 clk
->mode
= pmc_sys_mode
;
532 #ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
533 else if (clk_is_programmable(clk
)) {
534 clk
->mode
= pmc_sys_mode
;
535 init_programmable_clock(clk
);
544 /*------------------------------------------------------------------------*/
546 static u32 __init
at91_pll_rate(struct clk
*pll
, u32 freq
, u32 reg
)
551 mul
= (reg
>> 16) & 0x7ff;
561 static u32 __init
at91_usb_rate(struct clk
*pll
, u32 freq
, u32 reg
)
563 if (pll
== &pllb
&& (reg
& AT91_PMC_USB96M
))
569 static unsigned __init
at91_pll_calc(unsigned main_freq
, unsigned out_freq
)
571 unsigned i
, div
= 0, mul
= 0, diff
= 1 << 30;
572 unsigned ret
= (out_freq
> 155000000) ? 0xbe00 : 0x3e00;
574 /* PLL output max 240 MHz (or 180 MHz per errata) */
575 if (out_freq
> 240000000)
578 for (i
= 1; i
< 256; i
++) {
580 unsigned input
, mul1
;
583 * PLL input between 1MHz and 32MHz per spec, but lower
584 * frequences seem necessary in some cases so allow 100K.
585 * Warning: some newer products need 2MHz min.
587 input
= main_freq
/ i
;
588 if (cpu_is_at91sam9g20() && input
< 2000000)
592 if (input
> 32000000)
595 mul1
= out_freq
/ input
;
596 if (cpu_is_at91sam9g20() && mul
> 63)
603 diff1
= out_freq
- input
* mul1
;
614 if (i
== 256 && diff
> (out_freq
>> 5))
616 return ret
| ((mul
- 1) << 16) | div
;
621 static struct clk
*const standard_pmc_clocks
[] __initdata
= {
622 /* four primary clocks */
631 /* PLLB generated USB full speed clock init */
632 static void __init
at91_pllb_usbfs_clock_init(unsigned long main_clock
)
635 * USB clock init: choose 48 MHz PLLB value,
636 * disable 48MHz clock during usb peripheral suspend.
638 * REVISIT: assumes MCK doesn't derive from PLLB!
640 uhpck
.parent
= &pllb
;
642 at91_pllb_usb_init
= at91_pll_calc(main_clock
, 48000000 * 2) | AT91_PMC_USB96M
;
643 pllb
.rate_hz
= at91_pll_rate(&pllb
, main_clock
, at91_pllb_usb_init
);
644 if (cpu_is_at91rm9200()) {
645 uhpck
.pmc_mask
= AT91RM9200_PMC_UHP
;
646 udpck
.pmc_mask
= AT91RM9200_PMC_UDP
;
647 at91_pmc_write(AT91_PMC_SCER
, AT91RM9200_PMC_MCKUDP
);
648 } else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() ||
649 cpu_is_at91sam9263() || cpu_is_at91sam9g20() ||
650 cpu_is_at91sam9g10()) {
651 uhpck
.pmc_mask
= AT91SAM926x_PMC_UHP
;
652 udpck
.pmc_mask
= AT91SAM926x_PMC_UDP
;
654 at91_pmc_write(AT91_CKGR_PLLBR
, 0);
656 udpck
.rate_hz
= at91_usb_rate(&pllb
, pllb
.rate_hz
, at91_pllb_usb_init
);
657 uhpck
.rate_hz
= at91_usb_rate(&pllb
, pllb
.rate_hz
, at91_pllb_usb_init
);
660 /* UPLL generated USB full speed clock init */
661 static void __init
at91_upll_usbfs_clock_init(unsigned long main_clock
)
664 * USB clock init: choose 480 MHz from UPLL,
666 unsigned int usbr
= AT91_PMC_USBS_UPLL
;
668 /* Setup divider by 10 to reach 48 MHz */
669 usbr
|= ((10 - 1) << 8) & AT91_PMC_OHCIUSBDIV
;
671 at91_pmc_write(AT91_PMC_USB
, usbr
);
673 /* Now set uhpck values */
674 uhpck
.parent
= &utmi_clk
;
675 uhpck
.pmc_mask
= AT91SAM926x_PMC_UHP
;
676 uhpck
.rate_hz
= utmi_clk
.rate_hz
;
677 uhpck
.rate_hz
/= 1 + ((at91_pmc_read(AT91_PMC_USB
) & AT91_PMC_OHCIUSBDIV
) >> 8);
680 static int __init
at91_pmc_init(unsigned long main_clock
)
682 unsigned tmp
, freq
, mckr
;
684 int pll_overclock
= false;
687 * When the bootloader initialized the main oscillator correctly,
688 * there's no problem using the cycle counter. But if it didn't,
689 * or when using oscillator bypass mode, we must be told the speed
694 tmp
= at91_pmc_read(AT91_CKGR_MCFR
);
695 } while (!(tmp
& AT91_PMC_MAINRDY
));
696 main_clock
= (tmp
& AT91_PMC_MAINF
) * (AT91_SLOW_CLOCK
/ 16);
698 main_clk
.rate_hz
= main_clock
;
700 /* report if PLLA is more than mildly overclocked */
701 plla
.rate_hz
= at91_pll_rate(&plla
, main_clock
, at91_pmc_read(AT91_CKGR_PLLAR
));
702 if (cpu_has_300M_plla()) {
703 if (plla
.rate_hz
> 300000000)
704 pll_overclock
= true;
705 } else if (cpu_has_800M_plla()) {
706 if (plla
.rate_hz
> 800000000)
707 pll_overclock
= true;
709 if (plla
.rate_hz
> 209000000)
710 pll_overclock
= true;
713 pr_info("Clocks: PLLA overclocked, %ld MHz\n", plla
.rate_hz
/ 1000000);
715 if (cpu_has_plladiv2()) {
716 mckr
= at91_pmc_read(AT91_PMC_MCKR
);
717 plla
.rate_hz
/= (1 << ((mckr
& AT91_PMC_PLLADIV2
) >> 12)); /* plla divisor by 2 */
720 if (!cpu_has_pllb() && cpu_has_upll()) {
721 /* setup UTMI clock as the fourth primary clock
722 * (instead of pllb) */
723 utmi_clk
.type
|= CLK_TYPE_PRIMARY
;
731 if (cpu_has_utmi()) {
733 * multiplier is hard-wired to 40
734 * (obtain the USB High Speed 480 MHz when input is 12 MHz)
736 utmi_clk
.rate_hz
= 40 * utmi_clk
.parent
->rate_hz
;
738 /* UTMI bias and PLL are managed at the same time */
740 utmi_clk
.pmc_mask
|= AT91_PMC_BIASEN
;
747 at91_pllb_usbfs_clock_init(main_clock
);
749 /* assumes that we choose UPLL for USB and not PLLA */
750 at91_upll_usbfs_clock_init(main_clock
);
753 * MCK and CPU derive from one of those primary clocks.
754 * For now, assume this parentage won't change.
756 mckr
= at91_pmc_read(AT91_PMC_MCKR
);
757 mck
.parent
= at91_css_to_clk(mckr
& AT91_PMC_CSS
);
758 freq
= mck
.parent
->rate_hz
;
759 freq
/= pmc_prescaler_divider(mckr
); /* prescale */
760 if (cpu_is_at91rm9200()) {
761 mck
.rate_hz
= freq
/ (1 + ((mckr
& AT91_PMC_MDIV
) >> 8)); /* mdiv */
762 } else if (cpu_is_at91sam9g20()) {
763 mck
.rate_hz
= (mckr
& AT91_PMC_MDIV
) ?
764 freq
/ ((mckr
& AT91_PMC_MDIV
) >> 7) : freq
; /* mdiv ; (x >> 7) = ((x >> 8) * 2) */
765 if (mckr
& AT91_PMC_PDIV
)
766 freq
/= 2; /* processor clock division */
767 } else if (cpu_has_mdiv3()) {
768 mck
.rate_hz
= (mckr
& AT91_PMC_MDIV
) == AT91SAM9_PMC_MDIV_3
?
769 freq
/ 3 : freq
/ (1 << ((mckr
& AT91_PMC_MDIV
) >> 8)); /* mdiv */
771 mck
.rate_hz
= freq
/ (1 << ((mckr
& AT91_PMC_MDIV
) >> 8)); /* mdiv */
774 if (cpu_has_alt_prescaler()) {
775 /* Programmable clocks can use MCK */
776 mck
.type
|= CLK_TYPE_PRIMARY
;
780 /* Register the PMC's standard clocks */
781 for (i
= 0; i
< ARRAY_SIZE(standard_pmc_clocks
); i
++)
782 at91_clk_add(standard_pmc_clocks
[i
]);
788 at91_clk_add(&uhpck
);
791 at91_clk_add(&udpck
);
794 at91_clk_add(&utmi_clk
);
796 /* MCK and CPU clock are "always on" */
799 printk("Clocks: CPU %u MHz, master %u MHz, main %u.%03u MHz\n",
800 freq
/ 1000000, (unsigned) mck
.rate_hz
/ 1000000,
801 (unsigned) main_clock
/ 1000000,
802 ((unsigned) main_clock
% 1000000) / 1000);
807 #if defined(CONFIG_OF)
808 static struct of_device_id pmc_ids
[] = {
809 { .compatible
= "atmel,at91rm9200-pmc" },
813 static struct of_device_id osc_ids
[] = {
814 { .compatible
= "atmel,osc" },
818 int __init
at91_dt_clock_init(void)
820 struct device_node
*np
;
823 np
= of_find_matching_node(NULL
, pmc_ids
);
825 panic("unable to find compatible pmc node in dtb\n");
827 at91_pmc_base
= of_iomap(np
, 0);
829 panic("unable to map pmc cpu registers\n");
833 /* retrieve the freqency of fixed clocks from device tree */
834 np
= of_find_matching_node(NULL
, osc_ids
);
837 if (!of_property_read_u32(np
, "clock-frequency", &rate
))
843 return at91_pmc_init(main_clock
);
847 int __init
at91_clock_init(unsigned long main_clock
)
849 at91_pmc_base
= ioremap(AT91_PMC
, 256);
851 panic("Impossible to ioremap AT91_PMC 0x%x\n", AT91_PMC
);
853 return at91_pmc_init(main_clock
);
857 * Several unused clocks may be active. Turn them off.
859 static int __init
at91_clock_reset(void)
861 unsigned long pcdr
= 0;
862 unsigned long scdr
= 0;
865 list_for_each_entry(clk
, &clocks
, node
) {
869 if (clk
->mode
== pmc_periph_mode
)
870 pcdr
|= clk
->pmc_mask
;
872 if (clk
->mode
== pmc_sys_mode
)
873 scdr
|= clk
->pmc_mask
;
875 pr_debug("Clocks: disable unused %s\n", clk
->name
);
878 at91_pmc_write(AT91_PMC_PCDR
, pcdr
);
879 at91_pmc_write(AT91_PMC_SCDR
, scdr
);
883 late_initcall(at91_clock_reset
);
885 void at91sam9_idle(void)
887 at91_pmc_write(AT91_PMC_SCDR
, AT91_PMC_PCK
);