aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-ep93xx/clock.c
blob: 5f80092b6ace0ec1c9c6b0fea7c334a83029e67a (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
/*
 * arch/arm/mach-ep93xx/clock.c
 * Clock control for Cirrus EP93xx chips.
 *
 * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
 *
 * 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.
 */

#define pr_fmt(fmt) "ep93xx " KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/io.h>
#include <linux/spinlock.h>

#include <mach/hardware.h>

#include <asm/clkdev.h>
#include <asm/div64.h>


struct clk {
	struct clk	*parent;
	unsigned long	rate;
	int		users;
	int		sw_locked;
	void __iomem	*enable_reg;
	u32		enable_mask;

	unsigned long	(*get_rate)(struct clk *clk);
	int		(*set_rate)(struct clk *clk, unsigned long rate);
};


static unsigned long get_uart_rate(struct clk *clk);

static int set_keytchclk_rate(struct clk *clk, unsigned long rate);
static int set_div_rate(struct clk *clk, unsigned long rate);


static struct clk clk_xtali = {
	.rate		= EP93XX_EXT_CLK_RATE,
};
static struct clk clk_uart1 = {
	.parent		= &clk_xtali,
	.sw_locked	= 1,
	.enable_reg	= EP93XX_SYSCON_DEVCFG,
	.enable_mask	= EP93XX_SYSCON_DEVCFG_U1EN,
	.get_rate	= get_uart_rate,
};
static struct clk clk_uart2 = {
	.parent		= &clk_xtali,
	.sw_locked	= 1,
	.enable_reg	= EP93XX_SYSCON_DEVCFG,
	.enable_mask	= EP93XX_SYSCON_DEVCFG_U2EN,
	.get_rate	= get_uart_rate,
};
static struct clk clk_uart3 = {
	.parent		= &clk_xtali,
	.sw_locked	= 1,
	.enable_reg	= EP93XX_SYSCON_DEVCFG,
	.enable_mask	= EP93XX_SYSCON_DEVCFG_U3EN,
	.get_rate	= get_uart_rate,
};
static struct clk clk_pll1 = {
	.parent		= &clk_xtali,
};
static struct clk clk_f = {
	.parent		= &clk_pll1,
};
static struct clk clk_h = {
	.parent		= &clk_pll1,
};
static struct clk clk_p = {
	.parent		= &clk_pll1,
};
static struct clk clk_pll2 = {
	.parent		= &clk_xtali,
};
static struct clk clk_usb_host = {
	.parent		= &clk_pll2,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_USH_EN,
};
static struct clk clk_keypad = {
	.parent		= &clk_xtali,
	.sw_locked	= 1,
	.enable_reg	= EP93XX_SYSCON_KEYTCHCLKDIV,
	.enable_mask	= EP93XX_SYSCON_KEYTCHCLKDIV_KEN,
	.set_rate	= set_keytchclk_rate,
};
static struct clk clk_pwm = {
	.parent		= &clk_xtali,
	.rate		= EP93XX_EXT_CLK_RATE,
};

static struct clk clk_video = {
	.sw_locked	= 1,
	.enable_reg     = EP93XX_SYSCON_VIDCLKDIV,
	.enable_mask    = EP93XX_SYSCON_CLKDIV_ENABLE,
	.set_rate	= set_div_rate,
};

/* DMA Clocks */
static struct clk clk_m2p0 = {
	.parent		= &clk_h,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P0,
};
static struct clk clk_m2p1 = {
	.parent		= &clk_h,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P1,
};
static struct clk clk_m2p2 = {
	.parent		= &clk_h,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P2,
};
static struct clk clk_m2p3 = {
	.parent		= &clk_h,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P3,
};
static struct clk clk_m2p4 = {
	.parent		= &clk_h,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P4,
};
static struct clk clk_m2p5 = {
	.parent		= &clk_h,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P5,
};
static struct clk clk_m2p6 = {
	.parent		= &clk_h,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P6,
};
static struct clk clk_m2p7 = {
	.parent		= &clk_h,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P7,
};
static struct clk clk_m2p8 = {
	.parent		= &clk_h,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P8,
};
static struct clk clk_m2p9 = {
	.parent		= &clk_h,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P9,
};
static struct clk clk_m2m0 = {
	.parent		= &clk_h,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2M0,
};
static struct clk clk_m2m1 = {
	.parent		= &clk_h,
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2M1,
};

#define INIT_CK(dev,con,ck)					\
	{ .dev_id = dev, .con_id = con, .clk = ck }

static struct clk_lookup clocks[] = {
	INIT_CK(NULL,			"xtali",	&clk_xtali),
	INIT_CK("apb:uart1",		NULL,		&clk_uart1),
	INIT_CK("apb:uart2",		NULL,		&clk_uart2),
	INIT_CK("apb:uart3",		NULL,		&clk_uart3),
	INIT_CK(NULL,			"pll1",		&clk_pll1),
	INIT_CK(NULL,			"fclk",		&clk_f),
	INIT_CK(NULL,			"hclk",		&clk_h),
	INIT_CK(NULL,			"pclk",		&clk_p),
	INIT_CK(NULL,			"pll2",		&clk_pll2),
	INIT_CK("ep93xx-ohci",		NULL,		&clk_usb_host),
	INIT_CK("ep93xx-keypad",	NULL,		&clk_keypad),
	INIT_CK("ep93xx-fb",		NULL,		&clk_video),
	INIT_CK(NULL,			"pwm_clk",	&clk_pwm),
	INIT_CK(NULL,			"m2p0",		&clk_m2p0),
	INIT_CK(NULL,			"m2p1",		&clk_m2p1),
	INIT_CK(NULL,			"m2p2",		&clk_m2p2),
	INIT_CK(NULL,			"m2p3",		&clk_m2p3),
	INIT_CK(NULL,			"m2p4",		&clk_m2p4),
	INIT_CK(NULL,			"m2p5",		&clk_m2p5),
	INIT_CK(NULL,			"m2p6",		&clk_m2p6),
	INIT_CK(NULL,			"m2p7",		&clk_m2p7),
	INIT_CK(NULL,			"m2p8",		&clk_m2p8),
	INIT_CK(NULL,			"m2p9",		&clk_m2p9),
	INIT_CK(NULL,			"m2m0",		&clk_m2m0),
	INIT_CK(NULL,			"m2m1",		&clk_m2m1),
};

static DEFINE_SPINLOCK(clk_lock);

static void __clk_enable(struct clk *clk)
{
	if (!clk->users++) {
		if (clk->parent)
			__clk_enable(clk->parent);

		if (clk->enable_reg) {
			u32 v;

			v = __raw_readl(clk->enable_reg);
			v |= clk->enable_mask;
			if (clk->sw_locked)
				ep93xx_syscon_swlocked_write(v, clk->enable_reg);
			else
				__raw_writel(v, clk->enable_reg);
		}
	}
}

int clk_enable(struct clk *clk)
{
	unsigned long flags;

	if (!clk)
		return -EINVAL;

	spin_lock_irqsave(&clk_lock, flags);
	__clk_enable(clk);
	spin_unlock_irqrestore(&clk_lock, flags);

	return 0;
}
EXPORT_SYMBOL(clk_enable);

static void __clk_disable(struct clk *clk)
{
	if (!--clk->users) {
		if (clk->enable_reg) {
			u32 v;

			v = __raw_readl(clk->enable_reg);
			v &= ~clk->enable_mask;
			if (clk->sw_locked)
				ep93xx_syscon_swlocked_write(v, clk->enable_reg);
			else
				__raw_writel(v, clk->enable_reg);
		}

		if (clk->parent)
			__clk_disable(clk->parent);
	}
}

void clk_disable(struct clk *clk)
{
	unsigned long flags;

	if (!clk)
		return;

	spin_lock_irqsave(&clk_lock, flags);
	__clk_disable(clk);
	spin_unlock_irqrestore(&clk_lock, flags);
}
EXPORT_SYMBOL(clk_disable);

static unsigned long get_uart_rate(struct clk *clk)
{
	unsigned long rate = clk_get_rate(clk->parent);
	u32 value;

	value = __raw_readl(EP93XX_SYSCON_PWRCNT);
	if (value & EP93XX_SYSCON_PWRCNT_UARTBAUD)
		return rate;
	else
		return rate / 2;
}

unsigned long clk_get_rate(struct clk *clk)
{
	if (clk->get_rate)
		return clk->get_rate(clk);

	return clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);

static int set_keytchclk_rate(struct clk *clk, unsigned long rate)
{
	u32 val;
	u32 div_bit;

	val = __raw_readl(clk->enable_reg);

	/*
	 * The Key Matrix and ADC clocks are configured using the same
	 * System Controller register.  The clock used will be either
	 * 1/4 or 1/16 the external clock rate depending on the
	 * EP93XX_SYSCON_KEYTCHCLKDIV_KDIV/EP93XX_SYSCON_KEYTCHCLKDIV_ADIV
	 * bit being set or cleared.
	 */
	div_bit = clk->enable_mask >> 15;

	if (rate == EP93XX_KEYTCHCLK_DIV4)
		val |= div_bit;
	else if (rate == EP93XX_KEYTCHCLK_DIV16)
		val &= ~div_bit;
	else
		return -EINVAL;

	ep93xx_syscon_swlocked_write(val, clk->enable_reg);
	clk->rate = rate;
	return 0;
}

static int calc_clk_div(struct clk *clk, unsigned long rate,
			int *psel, int *esel, int *pdiv, int *div)
{
	struct clk *mclk;
	unsigned long max_rate, actual_rate, mclk_rate, rate_err = -1;
	int i, found = 0, __div = 0, __pdiv = 0;

	/* Don't exceed the maximum rate */
	max_rate = max(max(clk_pll1.rate / 4, clk_pll2.rate / 4),
		       clk_xtali.rate / 4);
	rate = min(rate, max_rate);

	/*
	 * Try the two pll's and the external clock
	 * Because the valid predividers are 2, 2.5 and 3, we multiply
	 * all the clocks by 2 to avoid floating point math.
	 *
	 * This is based on the algorithm in the ep93xx raster guide:
	 * http://be-a-maverick.com/en/pubs/appNote/AN269REV1.pdf
	 *
	 */
	for (i = 0; i < 3; i++) {
		if (i == 0)
			mclk = &clk_xtali;
		else if (i == 1)
			mclk = &clk_pll1;
		else
			mclk = &clk_pll2;
		mclk_rate = mclk->rate * 2;

		/* Try each predivider value */
		for (__pdiv = 4; __pdiv <= 6; __pdiv++) {
			__div = mclk_rate / (rate * __pdiv);
			if (__div < 2 || __div > 127)
				continue;

			actual_rate = mclk_rate / (__pdiv * __div);

			if (!found || abs(actual_rate - rate) < rate_err) {
				*pdiv = __pdiv - 3;
				*div = __div;
				*psel = (i == 2);
				*esel = (i != 0);
				clk->parent = mclk;
				clk->rate = actual_rate;
				rate_err = abs(actual_rate - rate);
				found = 1;
			}
		}
	}

	if (!found)
		return -EINVAL;

	return 0;
}

static int set_div_rate(struct clk *clk, unsigned long rate)
{
	int err, psel = 0, esel = 0, pdiv = 0, div = 0;
	u32 val;

	err = calc_clk_div(clk, rate, &psel, &esel, &pdiv, &div);
	if (err)
		return err;

	/* Clear the esel, psel, pdiv and div bits */
	val = __raw_readl(clk->enable_reg);
	val &= ~0x7fff;

	/* Set the new esel, psel, pdiv and div bits for the new clock rate */
	val |= (esel ? EP93XX_SYSCON_CLKDIV_ESEL : 0) |
		(psel ? EP93XX_SYSCON_CLKDIV_PSEL : 0) |
		(pdiv << EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) | div;
	ep93xx_syscon_swlocked_write(val, clk->enable_reg);
	return 0;
}

int clk_set_rate(struct clk *clk, unsigned long rate)
{
	if (clk->set_rate)
		return clk->set_rate(clk, rate);

	return -EINVAL;
}
EXPORT_SYMBOL(clk_set_rate);


static char fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 };
static char hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 };
static char pclk_divisors[] = { 1, 2, 4, 8 };

/*
 * PLL rate = 14.7456 MHz * (X1FBD + 1) * (X2FBD + 1) / (X2IPD + 1) / 2^PS
 */
static unsigned long calc_pll_rate(u32 config_word)
{
	unsigned long long rate;
	int i;

	rate = clk_xtali.rate;
	rate *= ((config_word >> 11) & 0x1f) + 1;		/* X1FBD */
	rate *= ((config_word >> 5) & 0x3f) + 1;		/* X2FBD */
	do_div(rate, (config_word & 0x1f) + 1);			/* X2IPD */
	for (i = 0; i < ((config_word >> 16) & 3); i++)		/* PS */
		rate >>= 1;

	return (unsigned long)rate;
}

static void __init ep93xx_dma_clock_init(void)
{
	clk_m2p0.rate = clk_h.rate;
	clk_m2p1.rate = clk_h.rate;
	clk_m2p2.rate = clk_h.rate;
	clk_m2p3.rate = clk_h.rate;
	clk_m2p4.rate = clk_h.rate;
	clk_m2p5.rate = clk_h.rate;
	clk_m2p6.rate = clk_h.rate;
	clk_m2p7.rate = clk_h.rate;
	clk_m2p8.rate = clk_h.rate;
	clk_m2p9.rate = clk_h.rate;
	clk_m2m0.rate = clk_h.rate;
	clk_m2m1.rate = clk_h.rate;
}

static int __init ep93xx_clock_init(void)
{
	u32 value;

	/* Determine the bootloader configured pll1 rate */
	value = __raw_readl(EP93XX_SYSCON_CLKSET1);
	if (!(value & EP93XX_SYSCON_CLKSET1_NBYP1))
		clk_pll1.rate = clk_xtali.rate;
	else
		clk_pll1.rate = calc_pll_rate(value);

	/* Initialize the pll1 derived clocks */
	clk_f.rate = clk_pll1.rate / fclk_divisors[(value >> 25) & 0x7];
	clk_h.rate = clk_pll1.rate / hclk_divisors[(value >> 20) & 0x7];
	clk_p.rate = clk_h.rate / pclk_divisors[(value >> 18) & 0x3];
	ep93xx_dma_clock_init();

	/* Determine the bootloader configured pll2 rate */
	value = __raw_readl(EP93XX_SYSCON_CLKSET2);
	if (!(value & EP93XX_SYSCON_CLKSET2_NBYP2))
		clk_pll2.rate = clk_xtali.rate;
	else if (value & EP93XX_SYSCON_CLKSET2_PLL2_EN)
		clk_pll2.rate = calc_pll_rate(value);
	else
		clk_pll2.rate = 0;

	/* Initialize the pll2 derived clocks */
	clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1);

	pr_info("PLL1 running at %ld MHz, PLL2 at %ld MHz\n",
		clk_pll1.rate / 1000000, clk_pll2.rate / 1000000);
	pr_info("FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n",
		clk_f.rate / 1000000, clk_h.rate / 1000000,
		clk_p.rate / 1000000);

	clkdev_add_table(clocks, ARRAY_SIZE(clocks));
	return 0;
}
arch_initcall(ep93xx_clock_init);