1 /*
2  * Copyright (C) 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License along
15  * with this program; if not, write to the Free Software Foundation, Inc.,
16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17  */
18 
19 #include <linux/mm.h>
20 #include <linux/delay.h>
21 #include <linux/clk.h>
22 #include <linux/io.h>
23 #include <linux/jiffies.h>
24 #include <linux/clkdev.h>
25 
26 #include <asm/clkdev.h>
27 #include <asm/div64.h>
28 
29 #include <mach/mx23.h>
30 #include <mach/common.h>
31 #include <mach/clock.h>
32 
33 #include "regs-clkctrl-mx23.h"
34 
35 #define CLKCTRL_BASE_ADDR	MX23_IO_ADDRESS(MX23_CLKCTRL_BASE_ADDR)
36 #define DIGCTRL_BASE_ADDR	MX23_IO_ADDRESS(MX23_DIGCTL_BASE_ADDR)
37 
38 #define PARENT_RATE_SHIFT	8
39 
_raw_clk_enable(struct clk * clk)40 static int _raw_clk_enable(struct clk *clk)
41 {
42 	u32 reg;
43 
44 	if (clk->enable_reg) {
45 		reg = __raw_readl(clk->enable_reg);
46 		reg &= ~(1 << clk->enable_shift);
47 		__raw_writel(reg, clk->enable_reg);
48 	}
49 
50 	return 0;
51 }
52 
_raw_clk_disable(struct clk * clk)53 static void _raw_clk_disable(struct clk *clk)
54 {
55 	u32 reg;
56 
57 	if (clk->enable_reg) {
58 		reg = __raw_readl(clk->enable_reg);
59 		reg |= 1 << clk->enable_shift;
60 		__raw_writel(reg, clk->enable_reg);
61 	}
62 }
63 
64 /*
65  * ref_xtal_clk
66  */
ref_xtal_clk_get_rate(struct clk * clk)67 static unsigned long ref_xtal_clk_get_rate(struct clk *clk)
68 {
69 	return 24000000;
70 }
71 
72 static struct clk ref_xtal_clk = {
73 	.get_rate = ref_xtal_clk_get_rate,
74 };
75 
76 /*
77  * pll_clk
78  */
pll_clk_get_rate(struct clk * clk)79 static unsigned long pll_clk_get_rate(struct clk *clk)
80 {
81 	return 480000000;
82 }
83 
pll_clk_enable(struct clk * clk)84 static int pll_clk_enable(struct clk *clk)
85 {
86 	__raw_writel(BM_CLKCTRL_PLLCTRL0_POWER |
87 			BM_CLKCTRL_PLLCTRL0_EN_USB_CLKS,
88 			CLKCTRL_BASE_ADDR + HW_CLKCTRL_PLLCTRL0_SET);
89 
90 	/* Only a 10us delay is need. PLLCTRL1 LOCK bitfied is only a timer
91 	 * and is incorrect (excessive). Per definition of the PLLCTRL0
92 	 * POWER field, waiting at least 10us.
93 	 */
94 	udelay(10);
95 
96 	return 0;
97 }
98 
pll_clk_disable(struct clk * clk)99 static void pll_clk_disable(struct clk *clk)
100 {
101 	__raw_writel(BM_CLKCTRL_PLLCTRL0_POWER |
102 			BM_CLKCTRL_PLLCTRL0_EN_USB_CLKS,
103 			CLKCTRL_BASE_ADDR + HW_CLKCTRL_PLLCTRL0_CLR);
104 }
105 
106 static struct clk pll_clk = {
107 	 .get_rate = pll_clk_get_rate,
108 	 .enable = pll_clk_enable,
109 	 .disable = pll_clk_disable,
110 	 .parent = &ref_xtal_clk,
111 };
112 
113 /*
114  * ref_clk
115  */
116 #define _CLK_GET_RATE_REF(name, sr, ss)					\
117 static unsigned long name##_get_rate(struct clk *clk)			\
118 {									\
119 	unsigned long parent_rate;					\
120 	u32 reg, div;							\
121 									\
122 	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##sr);		\
123 	div = (reg >> BP_CLKCTRL_##sr##_##ss##FRAC) & 0x3f;		\
124 	parent_rate = clk_get_rate(clk->parent);			\
125 									\
126 	return SH_DIV((parent_rate >> PARENT_RATE_SHIFT) * 18,		\
127 			div, PARENT_RATE_SHIFT);			\
128 }
129 
130 _CLK_GET_RATE_REF(ref_cpu_clk, FRAC, CPU)
131 _CLK_GET_RATE_REF(ref_emi_clk, FRAC, EMI)
132 _CLK_GET_RATE_REF(ref_pix_clk, FRAC, PIX)
133 _CLK_GET_RATE_REF(ref_io_clk, FRAC, IO)
134 
135 #define _DEFINE_CLOCK_REF(name, er, es)					\
136 	static struct clk name = {					\
137 		.enable_reg	= CLKCTRL_BASE_ADDR + HW_CLKCTRL_##er,	\
138 		.enable_shift	= BP_CLKCTRL_##er##_CLKGATE##es,	\
139 		.get_rate	= name##_get_rate,			\
140 		.enable		= _raw_clk_enable,			\
141 		.disable	= _raw_clk_disable,			\
142 		.parent		= &pll_clk,				\
143 	}
144 
145 _DEFINE_CLOCK_REF(ref_cpu_clk, FRAC, CPU);
146 _DEFINE_CLOCK_REF(ref_emi_clk, FRAC, EMI);
147 _DEFINE_CLOCK_REF(ref_pix_clk, FRAC, PIX);
148 _DEFINE_CLOCK_REF(ref_io_clk, FRAC, IO);
149 
150 /*
151  * General clocks
152  *
153  * clk_get_rate
154  */
rtc_clk_get_rate(struct clk * clk)155 static unsigned long rtc_clk_get_rate(struct clk *clk)
156 {
157 	/* ref_xtal_clk is implemented as the only parent */
158 	return clk_get_rate(clk->parent) / 768;
159 }
160 
clk32k_clk_get_rate(struct clk * clk)161 static unsigned long clk32k_clk_get_rate(struct clk *clk)
162 {
163 	return clk->parent->get_rate(clk->parent) / 750;
164 }
165 
166 #define _CLK_GET_RATE(name, rs)						\
167 static unsigned long name##_get_rate(struct clk *clk)			\
168 {									\
169 	u32 reg, div;							\
170 									\
171 	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##rs);		\
172 									\
173 	if (clk->parent == &ref_xtal_clk)				\
174 		div = (reg & BM_CLKCTRL_##rs##_DIV_XTAL) >>		\
175 			BP_CLKCTRL_##rs##_DIV_XTAL;			\
176 	else								\
177 		div = (reg & BM_CLKCTRL_##rs##_DIV_##rs) >>		\
178 			BP_CLKCTRL_##rs##_DIV_##rs;			\
179 									\
180 	if (!div)							\
181 		return -EINVAL;						\
182 									\
183 	return clk_get_rate(clk->parent) / div;				\
184 }
185 
_CLK_GET_RATE(cpu_clk,CPU)186 _CLK_GET_RATE(cpu_clk, CPU)
187 _CLK_GET_RATE(emi_clk, EMI)
188 
189 #define _CLK_GET_RATE1(name, rs)					\
190 static unsigned long name##_get_rate(struct clk *clk)			\
191 {									\
192 	u32 reg, div;							\
193 									\
194 	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##rs);		\
195 	div = (reg & BM_CLKCTRL_##rs##_DIV) >> BP_CLKCTRL_##rs##_DIV;	\
196 									\
197 	if (!div)							\
198 		return -EINVAL;						\
199 									\
200 	return clk_get_rate(clk->parent) / div;				\
201 }
202 
203 _CLK_GET_RATE1(hbus_clk, HBUS)
204 _CLK_GET_RATE1(xbus_clk, XBUS)
205 _CLK_GET_RATE1(ssp_clk, SSP)
206 _CLK_GET_RATE1(gpmi_clk, GPMI)
207 _CLK_GET_RATE1(lcdif_clk, PIX)
208 
209 #define _CLK_GET_RATE_STUB(name)					\
210 static unsigned long name##_get_rate(struct clk *clk)			\
211 {									\
212 	return clk_get_rate(clk->parent);				\
213 }
214 
215 _CLK_GET_RATE_STUB(uart_clk)
216 _CLK_GET_RATE_STUB(audio_clk)
217 _CLK_GET_RATE_STUB(pwm_clk)
218 
219 /*
220  * clk_set_rate
221  */
222 static int cpu_clk_set_rate(struct clk *clk, unsigned long rate)
223 {
224 	u32 reg, bm_busy, div_max, d, f, div, frac;
225 	unsigned long diff, parent_rate, calc_rate;
226 	int i;
227 
228 	parent_rate = clk_get_rate(clk->parent);
229 
230 	if (clk->parent == &ref_xtal_clk) {
231 		div_max = BM_CLKCTRL_CPU_DIV_XTAL >> BP_CLKCTRL_CPU_DIV_XTAL;
232 		bm_busy = BM_CLKCTRL_CPU_BUSY_REF_XTAL;
233 		div = DIV_ROUND_UP(parent_rate, rate);
234 		if (div == 0 || div > div_max)
235 			return -EINVAL;
236 	} else {
237 		div_max = BM_CLKCTRL_CPU_DIV_CPU >> BP_CLKCTRL_CPU_DIV_CPU;
238 		bm_busy = BM_CLKCTRL_CPU_BUSY_REF_CPU;
239 		rate >>= PARENT_RATE_SHIFT;
240 		parent_rate >>= PARENT_RATE_SHIFT;
241 		diff = parent_rate;
242 		div = frac = 1;
243 		for (d = 1; d <= div_max; d++) {
244 			f = parent_rate * 18 / d / rate;
245 			if ((parent_rate * 18 / d) % rate)
246 				f++;
247 			if (f < 18 || f > 35)
248 				continue;
249 
250 			calc_rate = parent_rate * 18 / f / d;
251 			if (calc_rate > rate)
252 				continue;
253 
254 			if (rate - calc_rate < diff) {
255 				frac = f;
256 				div = d;
257 				diff = rate - calc_rate;
258 			}
259 
260 			if (diff == 0)
261 				break;
262 		}
263 
264 		if (diff == parent_rate)
265 			return -EINVAL;
266 
267 		reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_FRAC);
268 		reg &= ~BM_CLKCTRL_FRAC_CPUFRAC;
269 		reg |= frac;
270 		__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_FRAC);
271 	}
272 
273 	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU);
274 	reg &= ~BM_CLKCTRL_CPU_DIV_CPU;
275 	reg |= div << BP_CLKCTRL_CPU_DIV_CPU;
276 	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU);
277 
278 	for (i = 10000; i; i--)
279 		if (!(__raw_readl(CLKCTRL_BASE_ADDR +
280 					HW_CLKCTRL_CPU) & bm_busy))
281 			break;
282 	if (!i)	{
283 		pr_err("%s: divider writing timeout\n", __func__);
284 		return -ETIMEDOUT;
285 	}
286 
287 	return 0;
288 }
289 
290 #define _CLK_SET_RATE(name, dr)						\
291 static int name##_set_rate(struct clk *clk, unsigned long rate)		\
292 {									\
293 	u32 reg, div_max, div;						\
294 	unsigned long parent_rate;					\
295 	int i;								\
296 									\
297 	parent_rate = clk_get_rate(clk->parent);			\
298 	div_max = BM_CLKCTRL_##dr##_DIV >> BP_CLKCTRL_##dr##_DIV;	\
299 									\
300 	div = DIV_ROUND_UP(parent_rate, rate);				\
301 	if (div == 0 || div > div_max)					\
302 		return -EINVAL;						\
303 									\
304 	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##dr);		\
305 	reg &= ~BM_CLKCTRL_##dr##_DIV;					\
306 	reg |= div << BP_CLKCTRL_##dr##_DIV;				\
307 	if (reg & (1 << clk->enable_shift)) {				\
308 		pr_err("%s: clock is gated\n", __func__);		\
309 		return -EINVAL;						\
310 	}								\
311 	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_##dr);		\
312 									\
313 	for (i = 10000; i; i--)						\
314 		if (!(__raw_readl(CLKCTRL_BASE_ADDR +			\
315 			HW_CLKCTRL_##dr) & BM_CLKCTRL_##dr##_BUSY))	\
316 			break;						\
317 	if (!i)	{							\
318 		pr_err("%s: divider writing timeout\n", __func__);	\
319 		return -ETIMEDOUT;					\
320 	}								\
321 									\
322 	return 0;							\
323 }
324 
325 _CLK_SET_RATE(xbus_clk, XBUS)
326 _CLK_SET_RATE(ssp_clk, SSP)
327 _CLK_SET_RATE(gpmi_clk, GPMI)
328 _CLK_SET_RATE(lcdif_clk, PIX)
329 
330 #define _CLK_SET_RATE_STUB(name)					\
331 static int name##_set_rate(struct clk *clk, unsigned long rate)		\
332 {									\
333 	return -EINVAL;							\
334 }
335 
336 _CLK_SET_RATE_STUB(emi_clk)
337 _CLK_SET_RATE_STUB(uart_clk)
338 _CLK_SET_RATE_STUB(audio_clk)
339 _CLK_SET_RATE_STUB(pwm_clk)
340 _CLK_SET_RATE_STUB(clk32k_clk)
341 
342 /*
343  * clk_set_parent
344  */
345 #define _CLK_SET_PARENT(name, bit)					\
346 static int name##_set_parent(struct clk *clk, struct clk *parent)	\
347 {									\
348 	if (parent != clk->parent) {					\
349 		__raw_writel(BM_CLKCTRL_CLKSEQ_BYPASS_##bit,		\
350 			 CLKCTRL_BASE_ADDR + HW_CLKCTRL_CLKSEQ_TOG);	\
351 		clk->parent = parent;					\
352 	}								\
353 									\
354 	return 0;							\
355 }
356 
357 _CLK_SET_PARENT(cpu_clk, CPU)
358 _CLK_SET_PARENT(emi_clk, EMI)
359 _CLK_SET_PARENT(ssp_clk, SSP)
360 _CLK_SET_PARENT(gpmi_clk, GPMI)
361 _CLK_SET_PARENT(lcdif_clk, PIX)
362 
363 #define _CLK_SET_PARENT_STUB(name)					\
364 static int name##_set_parent(struct clk *clk, struct clk *parent)	\
365 {									\
366 	if (parent != clk->parent)					\
367 		return -EINVAL;						\
368 	else								\
369 		return 0;						\
370 }
371 
372 _CLK_SET_PARENT_STUB(uart_clk)
373 _CLK_SET_PARENT_STUB(audio_clk)
374 _CLK_SET_PARENT_STUB(pwm_clk)
375 _CLK_SET_PARENT_STUB(clk32k_clk)
376 
377 /*
378  * clk definition
379  */
380 static struct clk cpu_clk = {
381 	.get_rate = cpu_clk_get_rate,
382 	.set_rate = cpu_clk_set_rate,
383 	.set_parent = cpu_clk_set_parent,
384 	.parent = &ref_cpu_clk,
385 };
386 
387 static struct clk hbus_clk = {
388 	.get_rate = hbus_clk_get_rate,
389 	.parent = &cpu_clk,
390 };
391 
392 static struct clk xbus_clk = {
393 	.get_rate = xbus_clk_get_rate,
394 	.set_rate = xbus_clk_set_rate,
395 	.parent = &ref_xtal_clk,
396 };
397 
398 static struct clk rtc_clk = {
399 	.get_rate = rtc_clk_get_rate,
400 	.parent = &ref_xtal_clk,
401 };
402 
403 /* usb_clk gate is controlled in DIGCTRL other than CLKCTRL */
404 static struct clk usb_clk = {
405 	.enable_reg = DIGCTRL_BASE_ADDR,
406 	.enable_shift = 2,
407 	.enable = _raw_clk_enable,
408 	.disable = _raw_clk_disable,
409 	.parent = &pll_clk,
410 };
411 
412 #define _DEFINE_CLOCK(name, er, es, p)					\
413 	static struct clk name = {					\
414 		.enable_reg	= CLKCTRL_BASE_ADDR + HW_CLKCTRL_##er,	\
415 		.enable_shift	= BP_CLKCTRL_##er##_##es,		\
416 		.get_rate	= name##_get_rate,			\
417 		.set_rate	= name##_set_rate,			\
418 		.set_parent	= name##_set_parent,			\
419 		.enable		= _raw_clk_enable,			\
420 		.disable	= _raw_clk_disable,			\
421 		.parent		= p,					\
422 	}
423 
424 _DEFINE_CLOCK(emi_clk, EMI, CLKGATE, &ref_xtal_clk);
425 _DEFINE_CLOCK(ssp_clk, SSP, CLKGATE, &ref_xtal_clk);
426 _DEFINE_CLOCK(gpmi_clk, GPMI, CLKGATE, &ref_xtal_clk);
427 _DEFINE_CLOCK(lcdif_clk, PIX, CLKGATE, &ref_xtal_clk);
428 _DEFINE_CLOCK(uart_clk, XTAL, UART_CLK_GATE, &ref_xtal_clk);
429 _DEFINE_CLOCK(audio_clk, XTAL, FILT_CLK24M_GATE, &ref_xtal_clk);
430 _DEFINE_CLOCK(pwm_clk, XTAL, PWM_CLK24M_GATE, &ref_xtal_clk);
431 _DEFINE_CLOCK(clk32k_clk, XTAL, TIMROT_CLK32K_GATE, &ref_xtal_clk);
432 
433 #define _REGISTER_CLOCK(d, n, c) \
434 	{ \
435 		.dev_id = d, \
436 		.con_id = n, \
437 		.clk = &c, \
438 	},
439 
440 static struct clk_lookup lookups[] = {
441 	/* for amba bus driver */
442 	_REGISTER_CLOCK("duart", "apb_pclk", xbus_clk)
443 	/* for amba-pl011 driver */
444 	_REGISTER_CLOCK("duart", NULL, uart_clk)
445 	_REGISTER_CLOCK("mxs-auart.0", NULL, uart_clk)
446 	_REGISTER_CLOCK("rtc", NULL, rtc_clk)
447 	_REGISTER_CLOCK("mxs-dma-apbh", NULL, hbus_clk)
448 	_REGISTER_CLOCK("mxs-dma-apbx", NULL, xbus_clk)
449 	_REGISTER_CLOCK(NULL, "usb", usb_clk)
450 	_REGISTER_CLOCK(NULL, "audio", audio_clk)
451 	_REGISTER_CLOCK("mxs-pwm.0", NULL, pwm_clk)
452 	_REGISTER_CLOCK("mxs-pwm.1", NULL, pwm_clk)
453 	_REGISTER_CLOCK("mxs-pwm.2", NULL, pwm_clk)
454 	_REGISTER_CLOCK("mxs-pwm.3", NULL, pwm_clk)
455 	_REGISTER_CLOCK("mxs-pwm.4", NULL, pwm_clk)
456 	_REGISTER_CLOCK("imx23-fb", NULL, lcdif_clk)
457 };
458 
clk_misc_init(void)459 static int clk_misc_init(void)
460 {
461 	u32 reg;
462 	int i;
463 
464 	/* Fix up parent per register setting */
465 	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_CLKSEQ);
466 	cpu_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_CPU) ?
467 			&ref_xtal_clk : &ref_cpu_clk;
468 	emi_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_EMI) ?
469 			&ref_xtal_clk : &ref_emi_clk;
470 	ssp_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_SSP) ?
471 			&ref_xtal_clk : &ref_io_clk;
472 	gpmi_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_GPMI) ?
473 			&ref_xtal_clk : &ref_io_clk;
474 	lcdif_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_PIX) ?
475 			&ref_xtal_clk : &ref_pix_clk;
476 
477 	/* Use int div over frac when both are available */
478 	__raw_writel(BM_CLKCTRL_CPU_DIV_XTAL_FRAC_EN,
479 			CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU_CLR);
480 	__raw_writel(BM_CLKCTRL_CPU_DIV_CPU_FRAC_EN,
481 			CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU_CLR);
482 	__raw_writel(BM_CLKCTRL_HBUS_DIV_FRAC_EN,
483 			CLKCTRL_BASE_ADDR + HW_CLKCTRL_HBUS_CLR);
484 
485 	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_XBUS);
486 	reg &= ~BM_CLKCTRL_XBUS_DIV_FRAC_EN;
487 	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_XBUS);
488 
489 	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_SSP);
490 	reg &= ~BM_CLKCTRL_SSP_DIV_FRAC_EN;
491 	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_SSP);
492 
493 	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_GPMI);
494 	reg &= ~BM_CLKCTRL_GPMI_DIV_FRAC_EN;
495 	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_GPMI);
496 
497 	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_PIX);
498 	reg &= ~BM_CLKCTRL_PIX_DIV_FRAC_EN;
499 	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_PIX);
500 
501 	/*
502 	 * Set safe hbus clock divider. A divider of 3 ensure that
503 	 * the Vddd voltage required for the cpu clock is sufficiently
504 	 * high for the hbus clock.
505 	 */
506 	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_HBUS);
507 	reg &= BM_CLKCTRL_HBUS_DIV;
508 	reg |= 3 << BP_CLKCTRL_HBUS_DIV;
509 	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_HBUS);
510 
511 	for (i = 10000; i; i--)
512 		if (!(__raw_readl(CLKCTRL_BASE_ADDR +
513 			HW_CLKCTRL_HBUS) & BM_CLKCTRL_HBUS_BUSY))
514 			break;
515 	if (!i) {
516 		pr_err("%s: divider writing timeout\n", __func__);
517 		return -ETIMEDOUT;
518 	}
519 
520 	/* Gate off cpu clock in WFI for power saving */
521 	__raw_writel(BM_CLKCTRL_CPU_INTERRUPT_WAIT,
522 			CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU_SET);
523 
524 	/*
525 	 * 480 MHz seems too high to be ssp clock source directly,
526 	 * so set frac to get a 288 MHz ref_io.
527 	 */
528 	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_FRAC);
529 	reg &= ~BM_CLKCTRL_FRAC_IOFRAC;
530 	reg |= 30 << BP_CLKCTRL_FRAC_IOFRAC;
531 	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_FRAC);
532 
533 	return 0;
534 }
535 
mx23_clocks_init(void)536 int __init mx23_clocks_init(void)
537 {
538 	clk_misc_init();
539 
540 	/*
541 	 * source ssp clock from ref_io than ref_xtal,
542 	 * as ref_xtal only provides 24 MHz as maximum.
543 	 */
544 	clk_set_parent(&ssp_clk, &ref_io_clk);
545 
546 	clk_enable(&cpu_clk);
547 	clk_enable(&hbus_clk);
548 	clk_enable(&xbus_clk);
549 	clk_enable(&emi_clk);
550 	clk_enable(&uart_clk);
551 
552 	clkdev_add_table(lookups, ARRAY_SIZE(lookups));
553 
554 	mxs_timer_init(&clk32k_clk, MX23_INT_TIMER0);
555 
556 	return 0;
557 }
558