xref: /openbmc/u-boot/arch/arm/mach-tegra/clock.c (revision 9038cd53)
1 /*
2  * Copyright (c) 2010-2014, NVIDIA CORPORATION.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 /* Tegra SoC common clock control functions */
18 
19 #include <common.h>
20 #include <asm/io.h>
21 #include <asm/arch/clock.h>
22 #include <asm/arch/tegra.h>
23 #include <asm/arch-tegra/ap.h>
24 #include <asm/arch-tegra/clk_rst.h>
25 #include <asm/arch-tegra/timer.h>
26 #include <div64.h>
27 #include <fdtdec.h>
28 
29 /*
30  * This is our record of the current clock rate of each clock. We don't
31  * fill all of these in since we are only really interested in clocks which
32  * we use as parents.
33  */
34 static unsigned pll_rate[CLOCK_ID_COUNT];
35 
36 /*
37  * The oscillator frequency is fixed to one of four set values. Based on this
38  * the other clocks are set up appropriately.
39  */
40 static unsigned osc_freq[CLOCK_OSC_FREQ_COUNT] = {
41 	13000000,
42 	19200000,
43 	12000000,
44 	26000000,
45 };
46 
47 /* return 1 if a peripheral ID is in range */
48 #define clock_type_id_isvalid(id) ((id) >= 0 && \
49 		(id) < CLOCK_TYPE_COUNT)
50 
51 char pllp_valid = 1;	/* PLLP is set up correctly */
52 
53 /* return 1 if a periphc_internal_id is in range */
54 #define periphc_internal_id_isvalid(id) ((id) >= 0 && \
55 		(id) < PERIPHC_COUNT)
56 
57 /* number of clock outputs of a PLL */
58 static const u8 pll_num_clkouts[] = {
59 	1,	/* PLLC */
60 	1,	/* PLLM */
61 	4,	/* PLLP */
62 	1,	/* PLLA */
63 	0,	/* PLLU */
64 	0,	/* PLLD */
65 };
66 
67 int clock_get_osc_bypass(void)
68 {
69 	struct clk_rst_ctlr *clkrst =
70 			(struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
71 	u32 reg;
72 
73 	reg = readl(&clkrst->crc_osc_ctrl);
74 	return (reg & OSC_XOBP_MASK) >> OSC_XOBP_SHIFT;
75 }
76 
77 /* Returns a pointer to the registers of the given pll */
78 static struct clk_pll *get_pll(enum clock_id clkid)
79 {
80 	struct clk_rst_ctlr *clkrst =
81 			(struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
82 
83 	assert(clock_id_is_pll(clkid));
84 	if (clkid >= (enum clock_id)TEGRA_CLK_PLLS) {
85 		debug("%s: Invalid PLL\n", __func__);
86 		return NULL;
87 	}
88 	return &clkrst->crc_pll[clkid];
89 }
90 
91 __weak struct clk_pll_simple *clock_get_simple_pll(enum clock_id clkid)
92 {
93 	return NULL;
94 }
95 
96 int clock_ll_read_pll(enum clock_id clkid, u32 *divm, u32 *divn,
97 		u32 *divp, u32 *cpcon, u32 *lfcon)
98 {
99 	struct clk_pll *pll = get_pll(clkid);
100 	u32 data;
101 
102 	assert(clkid != CLOCK_ID_USB);
103 
104 	/* Safety check, adds to code size but is small */
105 	if (!clock_id_is_pll(clkid) || clkid == CLOCK_ID_USB)
106 		return -1;
107 	data = readl(&pll->pll_base);
108 	*divm = (data & PLL_DIVM_MASK) >> PLL_DIVM_SHIFT;
109 	*divn = (data & PLL_DIVN_MASK) >> PLL_DIVN_SHIFT;
110 	*divp = (data & PLL_DIVP_MASK) >> PLL_DIVP_SHIFT;
111 	data = readl(&pll->pll_misc);
112 	*cpcon = (data & PLL_CPCON_MASK) >> PLL_CPCON_SHIFT;
113 	*lfcon = (data & PLL_LFCON_MASK) >> PLL_LFCON_SHIFT;
114 
115 	return 0;
116 }
117 
118 unsigned long clock_start_pll(enum clock_id clkid, u32 divm, u32 divn,
119 		u32 divp, u32 cpcon, u32 lfcon)
120 {
121 	struct clk_pll *pll = get_pll(clkid);
122 	u32 misc_data, data;
123 
124 	/*
125 	 * We cheat by treating all PLL (except PLLU) in the same fashion.
126 	 * This works only because:
127 	 * - same fields are always mapped at same offsets, except DCCON
128 	 * - DCCON is always 0, doesn't conflict
129 	 * - M,N, P of PLLP values are ignored for PLLP
130 	 */
131 	misc_data = (cpcon << PLL_CPCON_SHIFT) | (lfcon << PLL_LFCON_SHIFT);
132 
133 	data = (divm << PLL_DIVM_SHIFT) | (divn << PLL_DIVN_SHIFT) |
134 			(0 << PLL_BYPASS_SHIFT) | (1 << PLL_ENABLE_SHIFT);
135 
136 	if (clkid == CLOCK_ID_USB)
137 		data |= divp << PLLU_VCO_FREQ_SHIFT;
138 	else
139 		data |= divp << PLL_DIVP_SHIFT;
140 	if (pll) {
141 		writel(misc_data, &pll->pll_misc);
142 		writel(data, &pll->pll_base);
143 	} else {
144 		struct clk_pll_simple *pll = clock_get_simple_pll(clkid);
145 
146 		if (!pll) {
147 			debug("%s: Uknown simple PLL %d\n", __func__, clkid);
148 			return 0;
149 		}
150 		writel(misc_data, &pll->pll_misc);
151 		writel(data, &pll->pll_base);
152 	}
153 
154 	/* calculate the stable time */
155 	return timer_get_us() + CLOCK_PLL_STABLE_DELAY_US;
156 }
157 
158 void clock_ll_set_source_divisor(enum periph_id periph_id, unsigned source,
159 			unsigned divisor)
160 {
161 	u32 *reg = get_periph_source_reg(periph_id);
162 	u32 value;
163 
164 	value = readl(reg);
165 
166 	value &= ~OUT_CLK_SOURCE_31_30_MASK;
167 	value |= source << OUT_CLK_SOURCE_31_30_SHIFT;
168 
169 	value &= ~OUT_CLK_DIVISOR_MASK;
170 	value |= divisor << OUT_CLK_DIVISOR_SHIFT;
171 
172 	writel(value, reg);
173 }
174 
175 int clock_ll_set_source_bits(enum periph_id periph_id, int mux_bits,
176 			     unsigned source)
177 {
178 	u32 *reg = get_periph_source_reg(periph_id);
179 
180 	switch (mux_bits) {
181 	case MASK_BITS_31_30:
182 		clrsetbits_le32(reg, OUT_CLK_SOURCE_31_30_MASK,
183 				source << OUT_CLK_SOURCE_31_30_SHIFT);
184 		break;
185 
186 	case MASK_BITS_31_29:
187 		clrsetbits_le32(reg, OUT_CLK_SOURCE_31_29_MASK,
188 				source << OUT_CLK_SOURCE_31_29_SHIFT);
189 		break;
190 
191 	case MASK_BITS_31_28:
192 		clrsetbits_le32(reg, OUT_CLK_SOURCE_31_28_MASK,
193 				source << OUT_CLK_SOURCE_31_28_SHIFT);
194 		break;
195 
196 	default:
197 		return -1;
198 	}
199 
200 	return 0;
201 }
202 
203 void clock_ll_set_source(enum periph_id periph_id, unsigned source)
204 {
205 	clock_ll_set_source_bits(periph_id, MASK_BITS_31_30, source);
206 }
207 
208 /**
209  * Given the parent's rate and the required rate for the children, this works
210  * out the peripheral clock divider to use, in 7.1 binary format.
211  *
212  * @param divider_bits	number of divider bits (8 or 16)
213  * @param parent_rate	clock rate of parent clock in Hz
214  * @param rate		required clock rate for this clock
215  * @return divider which should be used
216  */
217 static int clk_get_divider(unsigned divider_bits, unsigned long parent_rate,
218 			   unsigned long rate)
219 {
220 	u64 divider = parent_rate * 2;
221 	unsigned max_divider = 1 << divider_bits;
222 
223 	divider += rate - 1;
224 	do_div(divider, rate);
225 
226 	if ((s64)divider - 2 < 0)
227 		return 0;
228 
229 	if ((s64)divider - 2 >= max_divider)
230 		return -1;
231 
232 	return divider - 2;
233 }
234 
235 int clock_set_pllout(enum clock_id clkid, enum pll_out_id pllout, unsigned rate)
236 {
237 	struct clk_pll *pll = get_pll(clkid);
238 	int data = 0, div = 0, offset = 0;
239 
240 	if (!clock_id_is_pll(clkid))
241 		return -1;
242 
243 	if (pllout + 1 > pll_num_clkouts[clkid])
244 		return -1;
245 
246 	div = clk_get_divider(8, pll_rate[clkid], rate);
247 
248 	if (div < 0)
249 		return -1;
250 
251 	/* out2 and out4 are in the high part of the register */
252 	if (pllout == PLL_OUT2 || pllout == PLL_OUT4)
253 		offset = 16;
254 
255 	data = (div << PLL_OUT_RATIO_SHIFT) |
256 			PLL_OUT_OVRRIDE | PLL_OUT_CLKEN | PLL_OUT_RSTN;
257 	clrsetbits_le32(&pll->pll_out[pllout >> 1],
258 			PLL_OUT_RATIO_MASK << offset, data << offset);
259 
260 	return 0;
261 }
262 
263 /**
264  * Given the parent's rate and the divider in 7.1 format, this works out the
265  * resulting peripheral clock rate.
266  *
267  * @param parent_rate	clock rate of parent clock in Hz
268  * @param divider which should be used in 7.1 format
269  * @return effective clock rate of peripheral
270  */
271 static unsigned long get_rate_from_divider(unsigned long parent_rate,
272 					   int divider)
273 {
274 	u64 rate;
275 
276 	rate = (u64)parent_rate * 2;
277 	do_div(rate, divider + 2);
278 	return rate;
279 }
280 
281 unsigned long clock_get_periph_rate(enum periph_id periph_id,
282 		enum clock_id parent)
283 {
284 	u32 *reg = get_periph_source_reg(periph_id);
285 
286 	return get_rate_from_divider(pll_rate[parent],
287 		(readl(reg) & OUT_CLK_DIVISOR_MASK) >> OUT_CLK_DIVISOR_SHIFT);
288 }
289 
290 /**
291  * Find the best available 7.1 format divisor given a parent clock rate and
292  * required child clock rate. This function assumes that a second-stage
293  * divisor is available which can divide by powers of 2 from 1 to 256.
294  *
295  * @param divider_bits	number of divider bits (8 or 16)
296  * @param parent_rate	clock rate of parent clock in Hz
297  * @param rate		required clock rate for this clock
298  * @param extra_div	value for the second-stage divisor (not set if this
299  *			function returns -1.
300  * @return divider which should be used, or -1 if nothing is valid
301  *
302  */
303 static int find_best_divider(unsigned divider_bits, unsigned long parent_rate,
304 				unsigned long rate, int *extra_div)
305 {
306 	int shift;
307 	int best_divider = -1;
308 	int best_error = rate;
309 
310 	/* try dividers from 1 to 256 and find closest match */
311 	for (shift = 0; shift <= 8 && best_error > 0; shift++) {
312 		unsigned divided_parent = parent_rate >> shift;
313 		int divider = clk_get_divider(divider_bits, divided_parent,
314 						rate);
315 		unsigned effective_rate = get_rate_from_divider(divided_parent,
316 						divider);
317 		int error = rate - effective_rate;
318 
319 		/* Given a valid divider, look for the lowest error */
320 		if (divider != -1 && error < best_error) {
321 			best_error = error;
322 			*extra_div = 1 << shift;
323 			best_divider = divider;
324 		}
325 	}
326 
327 	/* return what we found - *extra_div will already be set */
328 	return best_divider;
329 }
330 
331 /**
332  * Adjust peripheral PLL to use the given divider and source.
333  *
334  * @param periph_id	peripheral to adjust
335  * @param source	Source number (0-3 or 0-7)
336  * @param mux_bits	Number of mux bits (2 or 4)
337  * @param divider	Required divider in 7.1 or 15.1 format
338  * @return 0 if ok, -1 on error (requesting a parent clock which is not valid
339  *		for this peripheral)
340  */
341 static int adjust_periph_pll(enum periph_id periph_id, int source,
342 				int mux_bits, unsigned divider)
343 {
344 	u32 *reg = get_periph_source_reg(periph_id);
345 
346 	clrsetbits_le32(reg, OUT_CLK_DIVISOR_MASK,
347 			divider << OUT_CLK_DIVISOR_SHIFT);
348 	udelay(1);
349 
350 	/* work out the source clock and set it */
351 	if (source < 0)
352 		return -1;
353 
354 	clock_ll_set_source_bits(periph_id, mux_bits, source);
355 
356 	udelay(2);
357 	return 0;
358 }
359 
360 unsigned clock_adjust_periph_pll_div(enum periph_id periph_id,
361 		enum clock_id parent, unsigned rate, int *extra_div)
362 {
363 	unsigned effective_rate;
364 	int mux_bits, divider_bits, source;
365 	int divider;
366 	int xdiv = 0;
367 
368 	/* work out the source clock and set it */
369 	source = get_periph_clock_source(periph_id, parent, &mux_bits,
370 					 &divider_bits);
371 
372 	divider = find_best_divider(divider_bits, pll_rate[parent],
373 				    rate, &xdiv);
374 	if (extra_div)
375 		*extra_div = xdiv;
376 
377 	assert(divider >= 0);
378 	if (adjust_periph_pll(periph_id, source, mux_bits, divider))
379 		return -1U;
380 	debug("periph %d, rate=%d, reg=%p = %x\n", periph_id, rate,
381 		get_periph_source_reg(periph_id),
382 		readl(get_periph_source_reg(periph_id)));
383 
384 	/* Check what we ended up with. This shouldn't matter though */
385 	effective_rate = clock_get_periph_rate(periph_id, parent);
386 	if (extra_div)
387 		effective_rate /= *extra_div;
388 	if (rate != effective_rate)
389 		debug("Requested clock rate %u not honored (got %u)\n",
390 			rate, effective_rate);
391 	return effective_rate;
392 }
393 
394 unsigned clock_start_periph_pll(enum periph_id periph_id,
395 		enum clock_id parent, unsigned rate)
396 {
397 	unsigned effective_rate;
398 
399 	reset_set_enable(periph_id, 1);
400 	clock_enable(periph_id);
401 
402 	effective_rate = clock_adjust_periph_pll_div(periph_id, parent, rate,
403 						 NULL);
404 
405 	reset_set_enable(periph_id, 0);
406 	return effective_rate;
407 }
408 
409 void clock_enable(enum periph_id clkid)
410 {
411 	clock_set_enable(clkid, 1);
412 }
413 
414 void clock_disable(enum periph_id clkid)
415 {
416 	clock_set_enable(clkid, 0);
417 }
418 
419 void reset_periph(enum periph_id periph_id, int us_delay)
420 {
421 	/* Put peripheral into reset */
422 	reset_set_enable(periph_id, 1);
423 	udelay(us_delay);
424 
425 	/* Remove reset */
426 	reset_set_enable(periph_id, 0);
427 
428 	udelay(us_delay);
429 }
430 
431 void reset_cmplx_set_enable(int cpu, int which, int reset)
432 {
433 	struct clk_rst_ctlr *clkrst =
434 			(struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
435 	u32 mask;
436 
437 	/* Form the mask, which depends on the cpu chosen (2 or 4) */
438 	assert(cpu >= 0 && cpu < MAX_NUM_CPU);
439 	mask = which << cpu;
440 
441 	/* either enable or disable those reset for that CPU */
442 	if (reset)
443 		writel(mask, &clkrst->crc_cpu_cmplx_set);
444 	else
445 		writel(mask, &clkrst->crc_cpu_cmplx_clr);
446 }
447 
448 unsigned clock_get_rate(enum clock_id clkid)
449 {
450 	struct clk_pll *pll;
451 	u32 base;
452 	u32 divm;
453 	u64 parent_rate;
454 	u64 rate;
455 
456 	parent_rate = osc_freq[clock_get_osc_freq()];
457 	if (clkid == CLOCK_ID_OSC)
458 		return parent_rate;
459 
460 	pll = get_pll(clkid);
461 	if (!pll)
462 		return 0;
463 	base = readl(&pll->pll_base);
464 
465 	/* Oh for bf_unpack()... */
466 	rate = parent_rate * ((base & PLL_DIVN_MASK) >> PLL_DIVN_SHIFT);
467 	divm = (base & PLL_DIVM_MASK) >> PLL_DIVM_SHIFT;
468 	if (clkid == CLOCK_ID_USB)
469 		divm <<= (base & PLLU_VCO_FREQ_MASK) >> PLLU_VCO_FREQ_SHIFT;
470 	else
471 		divm <<= (base & PLL_DIVP_MASK) >> PLL_DIVP_SHIFT;
472 	do_div(rate, divm);
473 	return rate;
474 }
475 
476 /**
477  * Set the output frequency you want for each PLL clock.
478  * PLL output frequencies are programmed by setting their N, M and P values.
479  * The governing equations are:
480  *     VCO = (Fi / m) * n, Fo = VCO / (2^p)
481  *     where Fo is the output frequency from the PLL.
482  * Example: Set the output frequency to 216Mhz(Fo) with 12Mhz OSC(Fi)
483  *     216Mhz = ((12Mhz / m) * n) / (2^p) so n=432,m=12,p=1
484  * Please see Tegra TRM section 5.3 to get the detail for PLL Programming
485  *
486  * @param n PLL feedback divider(DIVN)
487  * @param m PLL input divider(DIVN)
488  * @param p post divider(DIVP)
489  * @param cpcon base PLL charge pump(CPCON)
490  * @return 0 if ok, -1 on error (the requested PLL is incorrect and cannot
491  *		be overriden), 1 if PLL is already correct
492  */
493 int clock_set_rate(enum clock_id clkid, u32 n, u32 m, u32 p, u32 cpcon)
494 {
495 	u32 base_reg;
496 	u32 misc_reg;
497 	struct clk_pll *pll;
498 
499 	pll = get_pll(clkid);
500 
501 	base_reg = readl(&pll->pll_base);
502 
503 	/* Set BYPASS, m, n and p to PLL_BASE */
504 	base_reg &= ~PLL_DIVM_MASK;
505 	base_reg |= m << PLL_DIVM_SHIFT;
506 
507 	base_reg &= ~PLL_DIVN_MASK;
508 	base_reg |= n << PLL_DIVN_SHIFT;
509 
510 	base_reg &= ~PLL_DIVP_MASK;
511 	base_reg |= p << PLL_DIVP_SHIFT;
512 
513 	if (clkid == CLOCK_ID_PERIPH) {
514 		/*
515 		 * If the PLL is already set up, check that it is correct
516 		 * and record this info for clock_verify() to check.
517 		 */
518 		if (base_reg & PLL_BASE_OVRRIDE_MASK) {
519 			base_reg |= PLL_ENABLE_MASK;
520 			if (base_reg != readl(&pll->pll_base))
521 				pllp_valid = 0;
522 			return pllp_valid ? 1 : -1;
523 		}
524 		base_reg |= PLL_BASE_OVRRIDE_MASK;
525 	}
526 
527 	base_reg |= PLL_BYPASS_MASK;
528 	writel(base_reg, &pll->pll_base);
529 
530 	/* Set cpcon to PLL_MISC */
531 	misc_reg = readl(&pll->pll_misc);
532 	misc_reg &= ~PLL_CPCON_MASK;
533 	misc_reg |= cpcon << PLL_CPCON_SHIFT;
534 	writel(misc_reg, &pll->pll_misc);
535 
536 	/* Enable PLL */
537 	base_reg |= PLL_ENABLE_MASK;
538 	writel(base_reg, &pll->pll_base);
539 
540 	/* Disable BYPASS */
541 	base_reg &= ~PLL_BYPASS_MASK;
542 	writel(base_reg, &pll->pll_base);
543 
544 	return 0;
545 }
546 
547 void clock_ll_start_uart(enum periph_id periph_id)
548 {
549 	/* Assert UART reset and enable clock */
550 	reset_set_enable(periph_id, 1);
551 	clock_enable(periph_id);
552 	clock_ll_set_source(periph_id, 0); /* UARTx_CLK_SRC = 00, PLLP_OUT0 */
553 
554 	/* wait for 2us */
555 	udelay(2);
556 
557 	/* De-assert reset to UART */
558 	reset_set_enable(periph_id, 0);
559 }
560 
561 #ifdef CONFIG_OF_CONTROL
562 int clock_decode_periph_id(const void *blob, int node)
563 {
564 	enum periph_id id;
565 	u32 cell[2];
566 	int err;
567 
568 	err = fdtdec_get_int_array(blob, node, "clocks", cell,
569 				   ARRAY_SIZE(cell));
570 	if (err)
571 		return -1;
572 	id = clk_id_to_periph_id(cell[1]);
573 	assert(clock_periph_id_isvalid(id));
574 	return id;
575 }
576 #endif /* CONFIG_OF_CONTROL */
577 
578 int clock_verify(void)
579 {
580 	struct clk_pll *pll = get_pll(CLOCK_ID_PERIPH);
581 	u32 reg = readl(&pll->pll_base);
582 
583 	if (!pllp_valid) {
584 		printf("Warning: PLLP %x is not correct\n", reg);
585 		return -1;
586 	}
587 	debug("PLLP %x is correct\n", reg);
588 	return 0;
589 }
590 
591 void clock_init(void)
592 {
593 	pll_rate[CLOCK_ID_MEMORY] = clock_get_rate(CLOCK_ID_MEMORY);
594 	pll_rate[CLOCK_ID_PERIPH] = clock_get_rate(CLOCK_ID_PERIPH);
595 	pll_rate[CLOCK_ID_CGENERAL] = clock_get_rate(CLOCK_ID_CGENERAL);
596 	pll_rate[CLOCK_ID_DISPLAY] = clock_get_rate(CLOCK_ID_DISPLAY);
597 	pll_rate[CLOCK_ID_OSC] = clock_get_rate(CLOCK_ID_OSC);
598 	pll_rate[CLOCK_ID_SFROM32KHZ] = 32768;
599 	pll_rate[CLOCK_ID_XCPU] = clock_get_rate(CLOCK_ID_XCPU);
600 	debug("Osc = %d\n", pll_rate[CLOCK_ID_OSC]);
601 	debug("PLLM = %d\n", pll_rate[CLOCK_ID_MEMORY]);
602 	debug("PLLP = %d\n", pll_rate[CLOCK_ID_PERIPH]);
603 	debug("PLLC = %d\n", pll_rate[CLOCK_ID_CGENERAL]);
604 	debug("PLLD = %d\n", pll_rate[CLOCK_ID_DISPLAY]);
605 	debug("PLLX = %d\n", pll_rate[CLOCK_ID_XCPU]);
606 
607 	/* Do any special system timer/TSC setup */
608 #if defined(CONFIG_TEGRA_SUPPORT_NON_SECURE)
609 	if (!tegra_cpu_is_non_secure())
610 #endif
611 		arch_timer_init();
612 }
613 
614 static void set_avp_clock_source(u32 src)
615 {
616 	struct clk_rst_ctlr *clkrst =
617 			(struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
618 	u32 val;
619 
620 	val = (src << SCLK_SWAKEUP_FIQ_SOURCE_SHIFT) |
621 		(src << SCLK_SWAKEUP_IRQ_SOURCE_SHIFT) |
622 		(src << SCLK_SWAKEUP_RUN_SOURCE_SHIFT) |
623 		(src << SCLK_SWAKEUP_IDLE_SOURCE_SHIFT) |
624 		(SCLK_SYS_STATE_RUN << SCLK_SYS_STATE_SHIFT);
625 	writel(val, &clkrst->crc_sclk_brst_pol);
626 	udelay(3);
627 }
628 
629 /*
630  * This function is useful on Tegra30, and any later SoCs that have compatible
631  * PLLP configuration registers.
632  */
633 void tegra30_set_up_pllp(void)
634 {
635 	struct clk_rst_ctlr *clkrst = (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
636 	u32 reg;
637 
638 	/*
639 	 * Based on the Tegra TRM, the system clock (which is the AVP clock) can
640 	 * run up to 275MHz. On power on, the default sytem clock source is set
641 	 * to PLLP_OUT0. This function sets PLLP's (hence PLLP_OUT0's) rate to
642 	 * 408MHz which is beyond system clock's upper limit.
643 	 *
644 	 * The fix is to set the system clock to CLK_M before initializing PLLP,
645 	 * and then switch back to PLLP_OUT4, which has an appropriate divider
646 	 * configured, after PLLP has been configured
647 	 */
648 	set_avp_clock_source(SCLK_SOURCE_CLKM);
649 
650 	/*
651 	 * PLLP output frequency set to 408Mhz
652 	 * PLLC output frequency set to 228Mhz
653 	 */
654 	switch (clock_get_osc_freq()) {
655 	case CLOCK_OSC_FREQ_12_0: /* OSC is 12Mhz */
656 		clock_set_rate(CLOCK_ID_PERIPH, 408, 12, 0, 8);
657 		clock_set_rate(CLOCK_ID_CGENERAL, 456, 12, 1, 8);
658 		break;
659 
660 	case CLOCK_OSC_FREQ_26_0: /* OSC is 26Mhz */
661 		clock_set_rate(CLOCK_ID_PERIPH, 408, 26, 0, 8);
662 		clock_set_rate(CLOCK_ID_CGENERAL, 600, 26, 0, 8);
663 		break;
664 
665 	case CLOCK_OSC_FREQ_13_0: /* OSC is 13Mhz */
666 		clock_set_rate(CLOCK_ID_PERIPH, 408, 13, 0, 8);
667 		clock_set_rate(CLOCK_ID_CGENERAL, 600, 13, 0, 8);
668 		break;
669 	case CLOCK_OSC_FREQ_19_2:
670 	default:
671 		/*
672 		 * These are not supported. It is too early to print a
673 		 * message and the UART likely won't work anyway due to the
674 		 * oscillator being wrong.
675 		 */
676 		break;
677 	}
678 
679 	/* Set PLLP_OUT1, 2, 3 & 4 freqs to 9.6, 48, 102 & 204MHz */
680 
681 	/* OUT1, 2 */
682 	/* Assert RSTN before enable */
683 	reg = PLLP_OUT2_RSTN_EN | PLLP_OUT1_RSTN_EN;
684 	writel(reg, &clkrst->crc_pll[CLOCK_ID_PERIPH].pll_out[0]);
685 	/* Set divisor and reenable */
686 	reg = (IN_408_OUT_48_DIVISOR << PLLP_OUT2_RATIO)
687 		| PLLP_OUT2_OVR | PLLP_OUT2_CLKEN | PLLP_OUT2_RSTN_DIS
688 		| (IN_408_OUT_9_6_DIVISOR << PLLP_OUT1_RATIO)
689 		| PLLP_OUT1_OVR | PLLP_OUT1_CLKEN | PLLP_OUT1_RSTN_DIS;
690 	writel(reg, &clkrst->crc_pll[CLOCK_ID_PERIPH].pll_out[0]);
691 
692 	/* OUT3, 4 */
693 	/* Assert RSTN before enable */
694 	reg = PLLP_OUT4_RSTN_EN | PLLP_OUT3_RSTN_EN;
695 	writel(reg, &clkrst->crc_pll[CLOCK_ID_PERIPH].pll_out[1]);
696 	/* Set divisor and reenable */
697 	reg = (IN_408_OUT_204_DIVISOR << PLLP_OUT4_RATIO)
698 		| PLLP_OUT4_OVR | PLLP_OUT4_CLKEN | PLLP_OUT4_RSTN_DIS
699 		| (IN_408_OUT_102_DIVISOR << PLLP_OUT3_RATIO)
700 		| PLLP_OUT3_OVR | PLLP_OUT3_CLKEN | PLLP_OUT3_RSTN_DIS;
701 	writel(reg, &clkrst->crc_pll[CLOCK_ID_PERIPH].pll_out[1]);
702 
703 	set_avp_clock_source(SCLK_SOURCE_PLLP_OUT4);
704 }
705