aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/mach-s3c2443/clock.c
blob: 38058af48972d7cf10409885b6e7578032a94d90 (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
/* linux/arch/arm/mach-s3c2443/clock.c
 *
 * Copyright (c) 2007, 2010 Simtec Electronics
 *	Ben Dooks <ben@simtec.co.uk>
 *
 * S3C2443 Clock control support
 *
 * 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/sysdev.h>
#include <linux/clk.h>
#include <linux/mutex.h>
#include <linux/serial_core.h>
#include <linux/io.h>

#include <asm/mach/map.h>

#include <mach/hardware.h>

#include <mach/regs-s3c2443-clock.h>

#include <plat/cpu-freq.h>

#include <plat/s3c2443.h>
#include <plat/clock.h>
#include <plat/clock-clksrc.h>
#include <plat/cpu.h>

/* We currently have to assume that the system is running
 * from the XTPll input, and that all ***REFCLKs are being
 * fed from it, as we cannot read the state of OM[4] from
 * software.
 *
 * It would be possible for each board initialisation to
 * set the correct muxing at initialisation
*/

/* clock selections */

static struct clk clk_i2s_ext = {
	.name		= "i2s-ext",
};

/* armdiv
 *
 * this clock is sourced from msysclk and can have a number of
 * divider values applied to it to then be fed into armclk.
*/

/* armdiv divisor table */

static unsigned int armdiv[16] = {
	[S3C2443_CLKDIV0_ARMDIV_1 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]	= 1,
	[S3C2443_CLKDIV0_ARMDIV_2 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]	= 2,
	[S3C2443_CLKDIV0_ARMDIV_3 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]	= 3,
	[S3C2443_CLKDIV0_ARMDIV_4 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]	= 4,
	[S3C2443_CLKDIV0_ARMDIV_6 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]	= 6,
	[S3C2443_CLKDIV0_ARMDIV_8 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]	= 8,
	[S3C2443_CLKDIV0_ARMDIV_12 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]	= 12,
	[S3C2443_CLKDIV0_ARMDIV_16 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]	= 16,
};

static inline unsigned int s3c2443_fclk_div(unsigned long clkcon0)
{
	clkcon0 &= S3C2443_CLKDIV0_ARMDIV_MASK;

	return armdiv[clkcon0 >> S3C2443_CLKDIV0_ARMDIV_SHIFT];
}

static unsigned long s3c2443_armclk_roundrate(struct clk *clk,
					      unsigned long rate)
{
	unsigned long parent = clk_get_rate(clk->parent);
	unsigned long calc;
	unsigned best = 256; /* bigger than any value */
	unsigned div;
	int ptr;

	for (ptr = 0; ptr < ARRAY_SIZE(armdiv); ptr++) {
		div = armdiv[ptr];
		calc = parent / div;
		if (calc <= rate && div < best)
			best = div;
	}

	return parent / best;
}

static int s3c2443_armclk_setrate(struct clk *clk, unsigned long rate)
{
	unsigned long parent = clk_get_rate(clk->parent);
	unsigned long calc;
	unsigned div;
	unsigned best = 256; /* bigger than any value */
	int ptr;
	int val = -1;

	for (ptr = 0; ptr < ARRAY_SIZE(armdiv); ptr++) {
		div = armdiv[ptr];
		calc = parent / div;
		if (calc <= rate && div < best) {
			best = div;
			val = ptr;
		}
	}

	if (val >= 0) {
		unsigned long clkcon0;

		clkcon0 = __raw_readl(S3C2443_CLKDIV0);
		clkcon0 &= ~S3C2443_CLKDIV0_ARMDIV_MASK;
		clkcon0 |= val << S3C2443_CLKDIV0_ARMDIV_SHIFT;
		__raw_writel(clkcon0, S3C2443_CLKDIV0);
	}

	return (val == -1) ? -EINVAL : 0;
}

static struct clk clk_armdiv = {
	.name		= "armdiv",
	.parent		= &clk_msysclk.clk,
	.ops		= &(struct clk_ops) {
		.round_rate = s3c2443_armclk_roundrate,
		.set_rate = s3c2443_armclk_setrate,
	},
};

/* armclk
 *
 * this is the clock fed into the ARM core itself, from armdiv or from hclk.
 */

static struct clk *clk_arm_sources[] = {
	[0] = &clk_armdiv,
	[1] = &clk_h,
};

static struct clksrc_clk clk_arm = {
	.clk	= {
		.name		= "armclk",
	},
	.sources = &(struct clksrc_sources) {
		.sources = clk_arm_sources,
		.nr_sources = ARRAY_SIZE(clk_arm_sources),
	},
	.reg_src = { .reg = S3C2443_CLKDIV0, .size = 1, .shift = 13 },
};

/* hsspi
 *
 * high-speed spi clock, sourced from esysclk
*/

static struct clksrc_clk clk_hsspi = {
	.clk	= {
		.name		= "hsspi",
		.parent		= &clk_esysclk.clk,
		.ctrlbit	= S3C2443_SCLKCON_HSSPICLK,
		.enable		= s3c2443_clkcon_enable_s,
	},
	.reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 4 },
};


/* clk_hsmcc_div
 *
 * this clock is sourced from epll, and is fed through a divider,
 * to a mux controlled by sclkcon where either it or a extclk can
 * be fed to the hsmmc block
*/

static struct clksrc_clk clk_hsmmc_div = {
	.clk	= {
		.name		= "hsmmc-div",
		.devname	= "s3c-sdhci.1",
		.parent		= &clk_esysclk.clk,
	},
	.reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 6 },
};

static int s3c2443_setparent_hsmmc(struct clk *clk, struct clk *parent)
{
	unsigned long clksrc = __raw_readl(S3C2443_SCLKCON);

	clksrc &= ~(S3C2443_SCLKCON_HSMMCCLK_EXT |
		    S3C2443_SCLKCON_HSMMCCLK_EPLL);

	if (parent == &clk_epll)
		clksrc |= S3C2443_SCLKCON_HSMMCCLK_EPLL;
	else if (parent == &clk_ext)
		clksrc |= S3C2443_SCLKCON_HSMMCCLK_EXT;
	else
		return -EINVAL;

	if (clk->usage > 0) {
		__raw_writel(clksrc, S3C2443_SCLKCON);
	}

	clk->parent = parent;
	return 0;
}

static int s3c2443_enable_hsmmc(struct clk *clk, int enable)
{
	return s3c2443_setparent_hsmmc(clk, clk->parent);
}

static struct clk clk_hsmmc = {
	.name		= "hsmmc-if",
	.devname	= "s3c-sdhci.1",
	.parent		= &clk_hsmmc_div.clk,
	.enable		= s3c2443_enable_hsmmc,
	.ops		= &(struct clk_ops) {
		.set_parent	= s3c2443_setparent_hsmmc,
	},
};

/* i2s_eplldiv
 *
 * This clock is the output from the I2S divisor of ESYSCLK, and is separate
 * from the mux that comes after it (cannot merge into one single clock)
*/

static struct clksrc_clk clk_i2s_eplldiv = {
	.clk	= {
		.name		= "i2s-eplldiv",
		.parent		= &clk_esysclk.clk,
	},
	.reg_div = { .reg = S3C2443_CLKDIV1, .size = 4, .shift = 12, },
};

/* i2s-ref
 *
 * i2s bus reference clock, selectable from external, esysclk or epllref
 *
 * Note, this used to be two clocks, but was compressed into one.
*/

struct clk *clk_i2s_srclist[] = {
	[0] = &clk_i2s_eplldiv.clk,
	[1] = &clk_i2s_ext,
	[2] = &clk_epllref.clk,
	[3] = &clk_epllref.clk,
};

static struct clksrc_clk clk_i2s = {
	.clk	= {
		.name		= "i2s-if",
		.ctrlbit	= S3C2443_SCLKCON_I2SCLK,
		.enable		= s3c2443_clkcon_enable_s,

	},
	.sources = &(struct clksrc_sources) {
		.sources = clk_i2s_srclist,
		.nr_sources = ARRAY_SIZE(clk_i2s_srclist),
	},
	.reg_src = { .reg = S3C2443_CLKSRC, .size = 2, .shift = 14 },
};

/* standard clock definitions */

static struct clk init_clocks_off[] = {
	{
		.name		= "sdi",
		.parent		= &clk_p,
		.enable		= s3c2443_clkcon_enable_p,
		.ctrlbit	= S3C2443_PCLKCON_SDI,
	}, {
		.name		= "iis",
		.parent		= &clk_p,
		.enable		= s3c2443_clkcon_enable_p,
		.ctrlbit	= S3C2443_PCLKCON_IIS,
	}, {
		.name		= "spi",
		.devname	= "s3c2410-spi.0",
		.parent		= &clk_p,
		.enable		= s3c2443_clkcon_enable_p,
		.ctrlbit	= S3C2443_PCLKCON_SPI0,
	}, {
		.name		= "spi",
		.devname	= "s3c2410-spi.1",
		.parent		= &clk_p,
		.enable		= s3c2443_clkcon_enable_p,
		.ctrlbit	= S3C2443_PCLKCON_SPI1,
	}
};

static struct clk init_clocks[] = {
};

/* clocks to add straight away */

static struct clksrc_clk *clksrcs[] __initdata = {
	&clk_arm,
	&clk_i2s_eplldiv,
	&clk_i2s,
	&clk_hsspi,
	&clk_hsmmc_div,
};

static struct clk *clks[] __initdata = {
	&clk_hsmmc,
	&clk_armdiv,
};

void __init_or_cpufreq s3c2443_setup_clocks(void)
{
	s3c2443_common_setup_clocks(s3c2443_get_mpll, s3c2443_fclk_div);
}

void __init s3c2443_init_clocks(int xtal)
{
	unsigned long epllcon = __raw_readl(S3C2443_EPLLCON);
	int ptr;

	clk_epll.rate = s3c2443_get_epll(epllcon, xtal);
	clk_epll.parent = &clk_epllref.clk;

	s3c2443_common_init_clocks(xtal, s3c2443_get_mpll, s3c2443_fclk_div);

	s3c2443_setup_clocks();

	s3c24xx_register_clocks(clks, ARRAY_SIZE(clks));

	for (ptr = 0; ptr < ARRAY_SIZE(clksrcs); ptr++)
		s3c_register_clksrc(clksrcs[ptr], 1);

	/* register clocks from clock array */

	s3c_register_clocks(init_clocks, ARRAY_SIZE(init_clocks));

	/* We must be careful disabling the clocks we are not intending to
	 * be using at boot time, as subsystems 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.
	*/

	/* install (and disable) the clocks we do not need immediately */

	s3c_register_clocks(init_clocks_off, ARRAY_SIZE(init_clocks_off));
	s3c_disable_clocks(init_clocks_off, ARRAY_SIZE(init_clocks_off));

	s3c_pwmclk_init();
}