summaryrefslogtreecommitdiff
path: root/arch/arm/mach-s3c2410/clock.c
blob: 99d174612b53ee34a5004842efc7c281f890d8b6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
/* linux/arch/arm/mach-s3c2410/clock.c
 *
 * Copyright (c) 2004-2005 Simtec Electronics
 *	Ben Dooks <ben@simtec.co.uk>
 *
 * S3C2410 Clock control support
 *
 * Based on, and code from linux/arch/arm/mach-versatile/clock.c
 **
 **  Copyright (C) 2004 ARM Limited.
 **  Written by Deep Blue Solutions Limited.
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/sysdev.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/clk.h>
#include <linux/mutex.h>
#include <linux/delay.h>

#include <asm/hardware.h>
#include <asm/irq.h>
#include <asm/io.h>

#include <asm/arch/regs-clock.h>
#include <asm/arch/regs-gpio.h>

#include "clock.h"
#include "cpu.h"

/* clock information */

static LIST_HEAD(clocks);

DEFINE_MUTEX(clocks_mutex);

/* old functions */

void inline s3c24xx_clk_enable(unsigned int clocks, unsigned int enable)
{
	unsigned long clkcon;

	clkcon = __raw_readl(S3C2410_CLKCON);

	if (enable)
		clkcon |= clocks;
	else
		clkcon &= ~clocks;

	/* ensure none of the special function bits set */
	clkcon &= ~(S3C2410_CLKCON_IDLE|S3C2410_CLKCON_POWER | 3);

	__raw_writel(clkcon, S3C2410_CLKCON);
}

/* enable and disable calls for use with the clk struct */

static int clk_null_enable(struct clk *clk, int enable)
{
	return 0;
}

int s3c24xx_clkcon_enable(struct clk *clk, int enable)
{
	s3c24xx_clk_enable(clk->ctrlbit, enable);
	return 0;
}

/* Clock API calls */

struct clk *clk_get(struct device *dev, const char *id)
{
	struct clk *p;
	struct clk *clk = ERR_PTR(-ENOENT);
	int idno;

	if (dev == NULL || dev->bus != &platform_bus_type)
		idno = -1;
	else
		idno = to_platform_device(dev)->id;

	mutex_lock(&clocks_mutex);

	list_for_each_entry(p, &clocks, list) {
		if (p->id == idno &&
		    strcmp(id, p->name) == 0 &&
		    try_module_get(p->owner)) {
			clk = p;
			break;
		}
	}

	/* check for the case where a device was supplied, but the
	 * clock that was being searched for is not device specific */

	if (IS_ERR(clk)) {
		list_for_each_entry(p, &clocks, list) {
			if (p->id == -1 && strcmp(id, p->name) == 0 &&
			    try_module_get(p->owner)) {
				clk = p;
				break;
			}
		}
	}

	mutex_unlock(&clocks_mutex);
	return clk;
}

void clk_put(struct clk *clk)
{
	module_put(clk->owner);
}

int clk_enable(struct clk *clk)
{
	if (IS_ERR(clk) || clk == NULL)
		return -EINVAL;

	clk_enable(clk->parent);

	mutex_lock(&clocks_mutex);

	if ((clk->usage++) == 0)
		(clk->enable)(clk, 1);

	mutex_unlock(&clocks_mutex);
	return 0;
}

void clk_disable(struct clk *clk)
{
	if (IS_ERR(clk) || clk == NULL)
		return;

	mutex_lock(&clocks_mutex);

	if ((--clk->usage) == 0)
		(clk->enable)(clk, 0);

	mutex_unlock(&clocks_mutex);
	clk_disable(clk->parent);
}


unsigned long clk_get_rate(struct clk *clk)
{
	if (IS_ERR(clk))
		return 0;

	if (clk->rate != 0)
		return clk->rate;

	while (clk->parent != NULL && clk->rate == 0)
		clk = clk->parent;

	return clk->rate;
}

long clk_round_rate(struct clk *clk, unsigned long rate)
{
	if (!IS_ERR(clk) && clk->round_rate)
		return (clk->round_rate)(clk, rate);

	return rate;
}

int clk_set_rate(struct clk *clk, unsigned long rate)
{
	int ret;

	if (IS_ERR(clk))
		return -EINVAL;

	mutex_lock(&clocks_mutex);
	ret = (clk->set_rate)(clk, rate);
	mutex_unlock(&clocks_mutex);

	return ret;
}

struct clk *clk_get_parent(struct clk *clk)
{
	return clk->parent;
}

int clk_set_parent(struct clk *clk, struct clk *parent)
{
	int ret = 0;

	if (IS_ERR(clk))
		return -EINVAL;

	mutex_lock(&clocks_mutex);

	if (clk->set_parent)
		ret = (clk->set_parent)(clk, parent);

	mutex_unlock(&clocks_mutex);

	return ret;
}

EXPORT_SYMBOL(clk_get);
EXPORT_SYMBOL(clk_put);
EXPORT_SYMBOL(clk_enable);
EXPORT_SYMBOL(clk_disable);
EXPORT_SYMBOL(clk_get_rate);
EXPORT_SYMBOL(clk_round_rate);
EXPORT_SYMBOL(clk_set_rate);
EXPORT_SYMBOL(clk_get_parent);
EXPORT_SYMBOL(clk_set_parent);

/* base clock enable */

static int s3c24xx_upll_enable(struct clk *clk, int enable)
{
	unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
	unsigned long orig = clkslow;

	if (enable)
		clkslow &= ~S3C2410_CLKSLOW_UCLK_OFF;
	else
		clkslow |= S3C2410_CLKSLOW_UCLK_OFF;

	__raw_writel(clkslow, S3C2410_CLKSLOW);

	/* if we started the UPLL, then allow to settle */

	if (enable && (orig & S3C2410_CLKSLOW_UCLK_OFF))
		udelay(200);

	return 0;
}

/* base clocks */

static struct clk clk_xtal = {
	.name		= "xtal",
	.id		= -1,
	.rate		= 0,
	.parent		= NULL,
	.ctrlbit	= 0,
};

static struct clk clk_upll = {
	.name		= "upll",
	.id		= -1,
	.parent		= NULL,
	.enable		= s3c24xx_upll_enable,
	.ctrlbit	= 0,
};

static struct clk clk_f = {
	.name		= "fclk",
	.id		= -1,
	.rate		= 0,
	.parent		= NULL,
	.ctrlbit	= 0,
};

static struct clk clk_h = {
	.name		= "hclk",
	.id		= -1,
	.rate		= 0,
	.parent		= NULL,
	.ctrlbit	= 0,
};

static struct clk clk_p = {
	.name		= "pclk",
	.id		= -1,
	.rate		= 0,
	.parent		= NULL,
	.ctrlbit	= 0,
};

struct clk clk_usb_bus = {
	.name		= "usb-bus",
	.id		= -1,
	.rate		= 0,
	.parent		= &clk_upll,
};

/* clocks that could be registered by external code */

static int s3c24xx_dclk_enable(struct clk *clk, int enable)
{
	unsigned long dclkcon = __raw_readl(S3C2410_DCLKCON);

	if (enable)
		dclkcon |= clk->ctrlbit;
	else
		dclkcon &= ~clk->ctrlbit;

	__raw_writel(dclkcon, S3C2410_DCLKCON);

	return 0;
}

static int s3c24xx_dclk_setparent(struct clk *clk, struct clk *parent)
{
	unsigned long dclkcon;
	unsigned int uclk;

	if (parent == &clk_upll)
		uclk = 1;
	else if (parent == &clk_p)
		uclk = 0;
	else
		return -EINVAL;

	clk->parent = parent;

	dclkcon = __raw_readl(S3C2410_DCLKCON);

	if (clk->ctrlbit == S3C2410_DCLKCON_DCLK0EN) {
		if (uclk)
			dclkcon |= S3C2410_DCLKCON_DCLK0_UCLK;
		else
			dclkcon &= ~S3C2410_DCLKCON_DCLK0_UCLK;
	} else {
		if (uclk)
			dclkcon |= S3C2410_DCLKCON_DCLK1_UCLK;
		else
			dclkcon &= ~S3C2410_DCLKCON_DCLK1_UCLK;
	}

	__raw_writel(dclkcon, S3C2410_DCLKCON);

	return 0;
}


static int s3c24xx_clkout_setparent(struct clk *clk, struct clk *parent)
{
	unsigned long mask;
	unsigned long source;

	/* calculate the MISCCR setting for the clock */

	if (parent == &clk_xtal)
		source = S3C2410_MISCCR_CLK0_MPLL;
	else if (parent == &clk_upll)
		source = S3C2410_MISCCR_CLK0_UPLL;
	else if (parent == &clk_f)
		source = S3C2410_MISCCR_CLK0_FCLK;
	else if (parent == &clk_h)
		source = S3C2410_MISCCR_CLK0_HCLK;
	else if (parent == &clk_p)
		source = S3C2410_MISCCR_CLK0_PCLK;
	else if (clk == &s3c24xx_clkout0 && parent == &s3c24xx_dclk0)
		source = S3C2410_MISCCR_CLK0_DCLK0;
	else if (clk == &s3c24xx_clkout1 && parent == &s3c24xx_dclk1)
		source = S3C2410_MISCCR_CLK0_DCLK0;
	else
		return -EINVAL;

	clk->parent = parent;

	if (clk == &s3c24xx_dclk0)
		mask = S3C2410_MISCCR_CLK0_MASK;
	else {
		source <<= 4;
		mask = S3C2410_MISCCR_CLK1_MASK;
	}

	s3c2410_modify_misccr(mask, source);
	return 0;
}

/* external clock definitions */

struct clk s3c24xx_dclk0 = {
	.name		= "dclk0",
	.id		= -1,
	.ctrlbit	= S3C2410_DCLKCON_DCLK0EN,
	.enable	        = s3c24xx_dclk_enable,
	.set_parent	= s3c24xx_dclk_setparent,
};

struct clk s3c24xx_dclk1 = {
	.name		= "dclk1",
	.id		= -1,
	.ctrlbit	= S3C2410_DCLKCON_DCLK0EN,
	.enable		= s3c24xx_dclk_enable,
	.set_parent	= s3c24xx_dclk_setparent,
};

struct clk s3c24xx_clkout0 = {
	.name		= "clkout0",
	.id		= -1,
	.set_parent	= s3c24xx_clkout_setparent,
};

struct clk s3c24xx_clkout1 = {
	.name		= "clkout1",
	.id		= -1,
	.set_parent	= s3c24xx_clkout_setparent,
};

struct clk s3c24xx_uclk = {
	.name		= "uclk",
	.id		= -1,
};


/* standard clock definitions */

static struct clk init_clocks[] = {
	{
		.name		= "nand",
		.id		= -1,
		.parent		= &clk_h,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_NAND,
	}, {
		.name		= "lcd",
		.id		= -1,
		.parent		= &clk_h,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_LCDC,
	}, {
		.name		= "usb-host",
		.id		= -1,
		.parent		= &clk_h,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_USBH,
	}, {
		.name		= "usb-device",
		.id		= -1,
		.parent		= &clk_h,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_USBD,
	}, {
		.name		= "timers",
		.id		= -1,
		.parent		= &clk_p,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_PWMT,
	}, {
		.name		= "sdi",
		.id		= -1,
		.parent		= &clk_p,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_SDI,
	}, {
		.name		= "uart",
		.id		= 0,
		.parent		= &clk_p,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_UART0,
	}, {
		.name		= "uart",
		.id		= 1,
		.parent		= &clk_p,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_UART1,
	}, {
		.name		= "uart",
		.id		= 2,
		.parent		= &clk_p,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_UART2,
	}, {
		.name		= "gpio",
		.id		= -1,
		.parent		= &clk_p,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_GPIO,
	}, {
		.name		= "rtc",
		.id		= -1,
		.parent		= &clk_p,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_RTC,
	}, {
		.name		= "adc",
		.id		= -1,
		.parent		= &clk_p,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_ADC,
	}, {
		.name		= "i2c",
		.id		= -1,
		.parent		= &clk_p,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_IIC,
	}, {
		.name		= "iis",
		.id		= -1,
		.parent		= &clk_p,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_IIS,
	}, {
		.name		= "spi",
		.id		= -1,
		.parent		= &clk_p,
		.enable		= s3c24xx_clkcon_enable,
		.ctrlbit	= S3C2410_CLKCON_SPI,
	}, {
		.name		= "watchdog",
		.id		= -1,
		.parent		= &clk_p,
		.ctrlbit	= 0,
	}
};

/* initialise the clock system */

int s3c24xx_register_clock(struct clk *clk)
{
	clk->owner = THIS_MODULE;

	if (clk->enable == NULL)
		clk->enable = clk_null_enable;

	/* if this is a standard clock, set the usage state */

	if (clk->ctrlbit && clk->enable == s3c24xx_clkcon_enable) {
		unsigned long clkcon = __raw_readl(S3C2410_CLKCON);

		clk->usage = (clkcon & clk->ctrlbit) ? 1 : 0;
	}

	/* add to the list of available clocks */

	mutex_lock(&clocks_mutex);
	list_add(&clk->list, &clocks);
	mutex_unlock(&clocks_mutex);

	return 0;
}

/* initalise all the clocks */

int __init s3c24xx_setup_clocks(unsigned long xtal,
				unsigned long fclk,
				unsigned long hclk,
				unsigned long pclk)
{
	unsigned long upllcon = __raw_readl(S3C2410_UPLLCON);
	unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
	struct clk *clkp = init_clocks;
	int ptr;
	int ret;

	printk(KERN_INFO "S3C2410 Clocks, (c) 2004 Simtec Electronics\n");

	/* initialise the main system clocks */

	clk_xtal.rate = xtal;
	clk_upll.rate = s3c2410_get_pll(upllcon, xtal);

	clk_h.rate = hclk;
	clk_p.rate = pclk;
	clk_f.rate = fclk;

	/* We must be careful disabling the clocks we are not intending to
	 * be using at boot time, as subsytems such as the LCD which do
	 * their own DMA requests to the bus can cause the system to lockup
	 * if they where in the middle of requesting bus access.
	 *
	 * Disabling the LCD clock if the LCD is active is very dangerous,
	 * and therefore the bootloader should be  careful to not enable
	 * the LCD clock if it is not needed.
	*/

	mutex_lock(&clocks_mutex);

	s3c24xx_clk_enable(S3C2410_CLKCON_NAND, 0);
	s3c24xx_clk_enable(S3C2410_CLKCON_USBH, 0);
	s3c24xx_clk_enable(S3C2410_CLKCON_USBD, 0);
	s3c24xx_clk_enable(S3C2410_CLKCON_ADC, 0);
	s3c24xx_clk_enable(S3C2410_CLKCON_IIC, 0);
	s3c24xx_clk_enable(S3C2410_CLKCON_SPI, 0);

	mutex_unlock(&clocks_mutex);

	/* assume uart clocks are correctly setup */

	/* register our clocks */

	if (s3c24xx_register_clock(&clk_xtal) < 0)
		printk(KERN_ERR "failed to register master xtal\n");

	if (s3c24xx_register_clock(&clk_upll) < 0)
		printk(KERN_ERR "failed to register upll clock\n");

	if (s3c24xx_register_clock(&clk_f) < 0)
		printk(KERN_ERR "failed to register cpu fclk\n");

	if (s3c24xx_register_clock(&clk_h) < 0)
		printk(KERN_ERR "failed to register cpu hclk\n");

	if (s3c24xx_register_clock(&clk_p) < 0)
		printk(KERN_ERR "failed to register cpu pclk\n");


	if (s3c24xx_register_clock(&clk_usb_bus) < 0)
		printk(KERN_ERR "failed to register usb bus clock\n");

	/* register clocks from clock array */

	for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
		ret = s3c24xx_register_clock(clkp);
		if (ret < 0) {
			printk(KERN_ERR "Failed to register clock %s (%d)\n",
			       clkp->name, ret);
		}
	}

	/* show the clock-slow value */

	printk("CLOCK: Slow mode (%ld.%ld MHz), %s, MPLL %s, UPLL %s\n",
	       print_mhz(xtal / ( 2 * S3C2410_CLKSLOW_GET_SLOWVAL(clkslow))),
	       (clkslow & S3C2410_CLKSLOW_SLOW) ? "slow" : "fast",
	       (clkslow & S3C2410_CLKSLOW_MPLL_OFF) ? "off" : "on",
	       (clkslow & S3C2410_CLKSLOW_UCLK_OFF) ? "off" : "on");

	return 0;
}