xref: /openbmc/linux/drivers/gpu/drm/omapdrm/dss/pll.c (revision eb7ebfa3)
1 /*
2  * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com/
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License version 2 as published by
6  * the Free Software Foundation.
7  *
8  * This program is distributed in the hope that 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 along with
14  * this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 #define DSS_SUBSYS_NAME "PLL"
18 
19 #include <linux/delay.h>
20 #include <linux/clk.h>
21 #include <linux/io.h>
22 #include <linux/kernel.h>
23 #include <linux/regulator/consumer.h>
24 #include <linux/sched.h>
25 
26 #include "omapdss.h"
27 #include "dss.h"
28 
29 #define PLL_CONTROL			0x0000
30 #define PLL_STATUS			0x0004
31 #define PLL_GO				0x0008
32 #define PLL_CONFIGURATION1		0x000C
33 #define PLL_CONFIGURATION2		0x0010
34 #define PLL_CONFIGURATION3		0x0014
35 #define PLL_SSC_CONFIGURATION1		0x0018
36 #define PLL_SSC_CONFIGURATION2		0x001C
37 #define PLL_CONFIGURATION4		0x0020
38 
39 int dss_pll_register(struct dss_device *dss, struct dss_pll *pll)
40 {
41 	int i;
42 
43 	for (i = 0; i < ARRAY_SIZE(dss->plls); ++i) {
44 		if (!dss->plls[i]) {
45 			dss->plls[i] = pll;
46 			pll->dss = dss;
47 			return 0;
48 		}
49 	}
50 
51 	return -EBUSY;
52 }
53 
54 void dss_pll_unregister(struct dss_pll *pll)
55 {
56 	struct dss_device *dss = pll->dss;
57 	int i;
58 
59 	for (i = 0; i < ARRAY_SIZE(dss->plls); ++i) {
60 		if (dss->plls[i] == pll) {
61 			dss->plls[i] = NULL;
62 			pll->dss = NULL;
63 			return;
64 		}
65 	}
66 }
67 
68 struct dss_pll *dss_pll_find(struct dss_device *dss, const char *name)
69 {
70 	int i;
71 
72 	for (i = 0; i < ARRAY_SIZE(dss->plls); ++i) {
73 		if (dss->plls[i] && strcmp(dss->plls[i]->name, name) == 0)
74 			return dss->plls[i];
75 	}
76 
77 	return NULL;
78 }
79 
80 struct dss_pll *dss_pll_find_by_src(struct dss_device *dss,
81 				    enum dss_clk_source src)
82 {
83 	struct dss_pll *pll;
84 
85 	switch (src) {
86 	default:
87 	case DSS_CLK_SRC_FCK:
88 		return NULL;
89 
90 	case DSS_CLK_SRC_HDMI_PLL:
91 		return dss_pll_find(dss, "hdmi");
92 
93 	case DSS_CLK_SRC_PLL1_1:
94 	case DSS_CLK_SRC_PLL1_2:
95 	case DSS_CLK_SRC_PLL1_3:
96 		pll = dss_pll_find(dss, "dsi0");
97 		if (!pll)
98 			pll = dss_pll_find(dss, "video0");
99 		return pll;
100 
101 	case DSS_CLK_SRC_PLL2_1:
102 	case DSS_CLK_SRC_PLL2_2:
103 	case DSS_CLK_SRC_PLL2_3:
104 		pll = dss_pll_find(dss, "dsi1");
105 		if (!pll)
106 			pll = dss_pll_find(dss, "video1");
107 		return pll;
108 	}
109 }
110 
111 unsigned int dss_pll_get_clkout_idx_for_src(enum dss_clk_source src)
112 {
113 	switch (src) {
114 	case DSS_CLK_SRC_HDMI_PLL:
115 		return 0;
116 
117 	case DSS_CLK_SRC_PLL1_1:
118 	case DSS_CLK_SRC_PLL2_1:
119 		return 0;
120 
121 	case DSS_CLK_SRC_PLL1_2:
122 	case DSS_CLK_SRC_PLL2_2:
123 		return 1;
124 
125 	case DSS_CLK_SRC_PLL1_3:
126 	case DSS_CLK_SRC_PLL2_3:
127 		return 2;
128 
129 	default:
130 		return 0;
131 	}
132 }
133 
134 int dss_pll_enable(struct dss_pll *pll)
135 {
136 	int r;
137 
138 	r = clk_prepare_enable(pll->clkin);
139 	if (r)
140 		return r;
141 
142 	if (pll->regulator) {
143 		r = regulator_enable(pll->regulator);
144 		if (r)
145 			goto err_reg;
146 	}
147 
148 	r = pll->ops->enable(pll);
149 	if (r)
150 		goto err_enable;
151 
152 	return 0;
153 
154 err_enable:
155 	if (pll->regulator)
156 		regulator_disable(pll->regulator);
157 err_reg:
158 	clk_disable_unprepare(pll->clkin);
159 	return r;
160 }
161 
162 void dss_pll_disable(struct dss_pll *pll)
163 {
164 	pll->ops->disable(pll);
165 
166 	if (pll->regulator)
167 		regulator_disable(pll->regulator);
168 
169 	clk_disable_unprepare(pll->clkin);
170 
171 	memset(&pll->cinfo, 0, sizeof(pll->cinfo));
172 }
173 
174 int dss_pll_set_config(struct dss_pll *pll, const struct dss_pll_clock_info *cinfo)
175 {
176 	int r;
177 
178 	r = pll->ops->set_config(pll, cinfo);
179 	if (r)
180 		return r;
181 
182 	pll->cinfo = *cinfo;
183 
184 	return 0;
185 }
186 
187 bool dss_pll_hsdiv_calc_a(const struct dss_pll *pll, unsigned long clkdco,
188 		unsigned long out_min, unsigned long out_max,
189 		dss_hsdiv_calc_func func, void *data)
190 {
191 	const struct dss_pll_hw *hw = pll->hw;
192 	int m, m_start, m_stop;
193 	unsigned long out;
194 
195 	out_min = out_min ? out_min : 1;
196 	out_max = out_max ? out_max : ULONG_MAX;
197 
198 	m_start = max(DIV_ROUND_UP(clkdco, out_max), 1ul);
199 
200 	m_stop = min((unsigned)(clkdco / out_min), hw->mX_max);
201 
202 	for (m = m_start; m <= m_stop; ++m) {
203 		out = clkdco / m;
204 
205 		if (func(m, out, data))
206 			return true;
207 	}
208 
209 	return false;
210 }
211 
212 /*
213  * clkdco = clkin / n * m * 2
214  * clkoutX = clkdco / mX
215  */
216 bool dss_pll_calc_a(const struct dss_pll *pll, unsigned long clkin,
217 		unsigned long pll_min, unsigned long pll_max,
218 		dss_pll_calc_func func, void *data)
219 {
220 	const struct dss_pll_hw *hw = pll->hw;
221 	int n, n_start, n_stop, n_inc;
222 	int m, m_start, m_stop, m_inc;
223 	unsigned long fint, clkdco;
224 	unsigned long pll_hw_max;
225 	unsigned long fint_hw_min, fint_hw_max;
226 
227 	pll_hw_max = hw->clkdco_max;
228 
229 	fint_hw_min = hw->fint_min;
230 	fint_hw_max = hw->fint_max;
231 
232 	n_start = max(DIV_ROUND_UP(clkin, fint_hw_max), 1ul);
233 	n_stop = min((unsigned)(clkin / fint_hw_min), hw->n_max);
234 	n_inc = 1;
235 
236 	if (hw->errata_i886) {
237 		swap(n_start, n_stop);
238 		n_inc = -1;
239 	}
240 
241 	pll_max = pll_max ? pll_max : ULONG_MAX;
242 
243 	for (n = n_start; n != n_stop; n += n_inc) {
244 		fint = clkin / n;
245 
246 		m_start = max(DIV_ROUND_UP(DIV_ROUND_UP(pll_min, fint), 2),
247 				1ul);
248 		m_stop = min3((unsigned)(pll_max / fint / 2),
249 				(unsigned)(pll_hw_max / fint / 2),
250 				hw->m_max);
251 		m_inc = 1;
252 
253 		if (hw->errata_i886) {
254 			swap(m_start, m_stop);
255 			m_inc = -1;
256 		}
257 
258 		for (m = m_start; m != m_stop; m += m_inc) {
259 			clkdco = 2 * m * fint;
260 
261 			if (func(n, m, fint, clkdco, data))
262 				return true;
263 		}
264 	}
265 
266 	return false;
267 }
268 
269 /*
270  * This calculates a PLL config that will provide the target_clkout rate
271  * for clkout. Additionally clkdco rate will be the same as clkout rate
272  * when clkout rate is >= min_clkdco.
273  *
274  * clkdco = clkin / n * m + clkin / n * mf / 262144
275  * clkout = clkdco / m2
276  */
277 bool dss_pll_calc_b(const struct dss_pll *pll, unsigned long clkin,
278 	unsigned long target_clkout, struct dss_pll_clock_info *cinfo)
279 {
280 	unsigned long fint, clkdco, clkout;
281 	unsigned long target_clkdco;
282 	unsigned long min_dco;
283 	unsigned int n, m, mf, m2, sd;
284 	const struct dss_pll_hw *hw = pll->hw;
285 
286 	DSSDBG("clkin %lu, target clkout %lu\n", clkin, target_clkout);
287 
288 	/* Fint */
289 	n = DIV_ROUND_UP(clkin, hw->fint_max);
290 	fint = clkin / n;
291 
292 	/* adjust m2 so that the clkdco will be high enough */
293 	min_dco = roundup(hw->clkdco_min, fint);
294 	m2 = DIV_ROUND_UP(min_dco, target_clkout);
295 	if (m2 == 0)
296 		m2 = 1;
297 
298 	target_clkdco = target_clkout * m2;
299 	m = target_clkdco / fint;
300 
301 	clkdco = fint * m;
302 
303 	/* adjust clkdco with fractional mf */
304 	if (WARN_ON(target_clkdco - clkdco > fint))
305 		mf = 0;
306 	else
307 		mf = (u32)div_u64(262144ull * (target_clkdco - clkdco), fint);
308 
309 	if (mf > 0)
310 		clkdco += (u32)div_u64((u64)mf * fint, 262144);
311 
312 	clkout = clkdco / m2;
313 
314 	/* sigma-delta */
315 	sd = DIV_ROUND_UP(fint * m, 250000000);
316 
317 	DSSDBG("N = %u, M = %u, M.f = %u, M2 = %u, SD = %u\n",
318 		n, m, mf, m2, sd);
319 	DSSDBG("Fint %lu, clkdco %lu, clkout %lu\n", fint, clkdco, clkout);
320 
321 	cinfo->n = n;
322 	cinfo->m = m;
323 	cinfo->mf = mf;
324 	cinfo->mX[0] = m2;
325 	cinfo->sd = sd;
326 
327 	cinfo->fint = fint;
328 	cinfo->clkdco = clkdco;
329 	cinfo->clkout[0] = clkout;
330 
331 	return true;
332 }
333 
334 static int wait_for_bit_change(void __iomem *reg, int bitnum, int value)
335 {
336 	unsigned long timeout;
337 	ktime_t wait;
338 	int t;
339 
340 	/* first busyloop to see if the bit changes right away */
341 	t = 100;
342 	while (t-- > 0) {
343 		if (FLD_GET(readl_relaxed(reg), bitnum, bitnum) == value)
344 			return value;
345 	}
346 
347 	/* then loop for 500ms, sleeping for 1ms in between */
348 	timeout = jiffies + msecs_to_jiffies(500);
349 	while (time_before(jiffies, timeout)) {
350 		if (FLD_GET(readl_relaxed(reg), bitnum, bitnum) == value)
351 			return value;
352 
353 		wait = ns_to_ktime(1000 * 1000);
354 		set_current_state(TASK_UNINTERRUPTIBLE);
355 		schedule_hrtimeout(&wait, HRTIMER_MODE_REL);
356 	}
357 
358 	return !value;
359 }
360 
361 int dss_pll_wait_reset_done(struct dss_pll *pll)
362 {
363 	void __iomem *base = pll->base;
364 
365 	if (wait_for_bit_change(base + PLL_STATUS, 0, 1) != 1)
366 		return -ETIMEDOUT;
367 	else
368 		return 0;
369 }
370 
371 static int dss_wait_hsdiv_ack(struct dss_pll *pll, u32 hsdiv_ack_mask)
372 {
373 	int t = 100;
374 
375 	while (t-- > 0) {
376 		u32 v = readl_relaxed(pll->base + PLL_STATUS);
377 		v &= hsdiv_ack_mask;
378 		if (v == hsdiv_ack_mask)
379 			return 0;
380 	}
381 
382 	return -ETIMEDOUT;
383 }
384 
385 static bool pll_is_locked(u32 stat)
386 {
387 	/*
388 	 * Required value for each bitfield listed below
389 	 *
390 	 * PLL_STATUS[6] = 0  PLL_BYPASS
391 	 * PLL_STATUS[5] = 0  PLL_HIGHJITTER
392 	 *
393 	 * PLL_STATUS[3] = 0  PLL_LOSSREF
394 	 * PLL_STATUS[2] = 0  PLL_RECAL
395 	 * PLL_STATUS[1] = 1  PLL_LOCK
396 	 * PLL_STATUS[0] = 1  PLL_CTRL_RESET_DONE
397 	 */
398 	return ((stat & 0x6f) == 0x3);
399 }
400 
401 int dss_pll_write_config_type_a(struct dss_pll *pll,
402 		const struct dss_pll_clock_info *cinfo)
403 {
404 	const struct dss_pll_hw *hw = pll->hw;
405 	void __iomem *base = pll->base;
406 	int r = 0;
407 	u32 l;
408 
409 	l = 0;
410 	if (hw->has_stopmode)
411 		l = FLD_MOD(l, 1, 0, 0);		/* PLL_STOPMODE */
412 	l = FLD_MOD(l, cinfo->n - 1, hw->n_msb, hw->n_lsb);	/* PLL_REGN */
413 	l = FLD_MOD(l, cinfo->m, hw->m_msb, hw->m_lsb);		/* PLL_REGM */
414 	/* M4 */
415 	l = FLD_MOD(l, cinfo->mX[0] ? cinfo->mX[0] - 1 : 0,
416 			hw->mX_msb[0], hw->mX_lsb[0]);
417 	/* M5 */
418 	l = FLD_MOD(l, cinfo->mX[1] ? cinfo->mX[1] - 1 : 0,
419 			hw->mX_msb[1], hw->mX_lsb[1]);
420 	writel_relaxed(l, base + PLL_CONFIGURATION1);
421 
422 	l = 0;
423 	/* M6 */
424 	l = FLD_MOD(l, cinfo->mX[2] ? cinfo->mX[2] - 1 : 0,
425 			hw->mX_msb[2], hw->mX_lsb[2]);
426 	/* M7 */
427 	l = FLD_MOD(l, cinfo->mX[3] ? cinfo->mX[3] - 1 : 0,
428 			hw->mX_msb[3], hw->mX_lsb[3]);
429 	writel_relaxed(l, base + PLL_CONFIGURATION3);
430 
431 	l = readl_relaxed(base + PLL_CONFIGURATION2);
432 	if (hw->has_freqsel) {
433 		u32 f = cinfo->fint < 1000000 ? 0x3 :
434 			cinfo->fint < 1250000 ? 0x4 :
435 			cinfo->fint < 1500000 ? 0x5 :
436 			cinfo->fint < 1750000 ? 0x6 :
437 			0x7;
438 
439 		l = FLD_MOD(l, f, 4, 1);	/* PLL_FREQSEL */
440 	} else if (hw->has_selfreqdco) {
441 		u32 f = cinfo->clkdco < hw->clkdco_low ? 0x2 : 0x4;
442 
443 		l = FLD_MOD(l, f, 3, 1);	/* PLL_SELFREQDCO */
444 	}
445 	l = FLD_MOD(l, 1, 13, 13);		/* PLL_REFEN */
446 	l = FLD_MOD(l, 0, 14, 14);		/* PHY_CLKINEN */
447 	l = FLD_MOD(l, 0, 16, 16);		/* M4_CLOCK_EN */
448 	l = FLD_MOD(l, 0, 18, 18);		/* M5_CLOCK_EN */
449 	l = FLD_MOD(l, 1, 20, 20);		/* HSDIVBYPASS */
450 	if (hw->has_refsel)
451 		l = FLD_MOD(l, 3, 22, 21);	/* REFSEL = sysclk */
452 	l = FLD_MOD(l, 0, 23, 23);		/* M6_CLOCK_EN */
453 	l = FLD_MOD(l, 0, 25, 25);		/* M7_CLOCK_EN */
454 	writel_relaxed(l, base + PLL_CONFIGURATION2);
455 
456 	if (hw->errata_i932) {
457 		int cnt = 0;
458 		u32 sleep_time;
459 		const u32 max_lock_retries = 20;
460 
461 		/*
462 		 * Calculate wait time for PLL LOCK
463 		 * 1000 REFCLK cycles in us.
464 		 */
465 		sleep_time = DIV_ROUND_UP(1000*1000*1000, cinfo->fint);
466 
467 		for (cnt = 0; cnt < max_lock_retries; cnt++) {
468 			writel_relaxed(1, base + PLL_GO);	/* PLL_GO */
469 
470 			/**
471 			 * read the register back to ensure the write is
472 			 * flushed
473 			 */
474 			readl_relaxed(base + PLL_GO);
475 
476 			usleep_range(sleep_time, sleep_time + 5);
477 			l = readl_relaxed(base + PLL_STATUS);
478 
479 			if (pll_is_locked(l) &&
480 			    !(readl_relaxed(base + PLL_GO) & 0x1))
481 				break;
482 
483 		}
484 
485 		if (cnt == max_lock_retries) {
486 			DSSERR("cannot lock PLL\n");
487 			r = -EIO;
488 			goto err;
489 		}
490 	} else {
491 		writel_relaxed(1, base + PLL_GO);	/* PLL_GO */
492 
493 		if (wait_for_bit_change(base + PLL_GO, 0, 0) != 0) {
494 			DSSERR("DSS DPLL GO bit not going down.\n");
495 			r = -EIO;
496 			goto err;
497 		}
498 
499 		if (wait_for_bit_change(base + PLL_STATUS, 1, 1) != 1) {
500 			DSSERR("cannot lock DSS DPLL\n");
501 			r = -EIO;
502 			goto err;
503 		}
504 	}
505 
506 	l = readl_relaxed(base + PLL_CONFIGURATION2);
507 	l = FLD_MOD(l, 1, 14, 14);			/* PHY_CLKINEN */
508 	l = FLD_MOD(l, cinfo->mX[0] ? 1 : 0, 16, 16);	/* M4_CLOCK_EN */
509 	l = FLD_MOD(l, cinfo->mX[1] ? 1 : 0, 18, 18);	/* M5_CLOCK_EN */
510 	l = FLD_MOD(l, 0, 20, 20);			/* HSDIVBYPASS */
511 	l = FLD_MOD(l, cinfo->mX[2] ? 1 : 0, 23, 23);	/* M6_CLOCK_EN */
512 	l = FLD_MOD(l, cinfo->mX[3] ? 1 : 0, 25, 25);	/* M7_CLOCK_EN */
513 	writel_relaxed(l, base + PLL_CONFIGURATION2);
514 
515 	r = dss_wait_hsdiv_ack(pll,
516 		(cinfo->mX[0] ? BIT(7) : 0) |
517 		(cinfo->mX[1] ? BIT(8) : 0) |
518 		(cinfo->mX[2] ? BIT(10) : 0) |
519 		(cinfo->mX[3] ? BIT(11) : 0));
520 	if (r) {
521 		DSSERR("failed to enable HSDIV clocks\n");
522 		goto err;
523 	}
524 
525 err:
526 	return r;
527 }
528 
529 int dss_pll_write_config_type_b(struct dss_pll *pll,
530 		const struct dss_pll_clock_info *cinfo)
531 {
532 	const struct dss_pll_hw *hw = pll->hw;
533 	void __iomem *base = pll->base;
534 	u32 l;
535 
536 	l = 0;
537 	l = FLD_MOD(l, cinfo->m, 20, 9);	/* PLL_REGM */
538 	l = FLD_MOD(l, cinfo->n - 1, 8, 1);	/* PLL_REGN */
539 	writel_relaxed(l, base + PLL_CONFIGURATION1);
540 
541 	l = readl_relaxed(base + PLL_CONFIGURATION2);
542 	l = FLD_MOD(l, 0x0, 12, 12);	/* PLL_HIGHFREQ divide by 2 */
543 	l = FLD_MOD(l, 0x1, 13, 13);	/* PLL_REFEN */
544 	l = FLD_MOD(l, 0x0, 14, 14);	/* PHY_CLKINEN */
545 	if (hw->has_refsel)
546 		l = FLD_MOD(l, 0x3, 22, 21);	/* REFSEL = SYSCLK */
547 
548 	/* PLL_SELFREQDCO */
549 	if (cinfo->clkdco > hw->clkdco_low)
550 		l = FLD_MOD(l, 0x4, 3, 1);
551 	else
552 		l = FLD_MOD(l, 0x2, 3, 1);
553 	writel_relaxed(l, base + PLL_CONFIGURATION2);
554 
555 	l = readl_relaxed(base + PLL_CONFIGURATION3);
556 	l = FLD_MOD(l, cinfo->sd, 17, 10);	/* PLL_REGSD */
557 	writel_relaxed(l, base + PLL_CONFIGURATION3);
558 
559 	l = readl_relaxed(base + PLL_CONFIGURATION4);
560 	l = FLD_MOD(l, cinfo->mX[0], 24, 18);	/* PLL_REGM2 */
561 	l = FLD_MOD(l, cinfo->mf, 17, 0);	/* PLL_REGM_F */
562 	writel_relaxed(l, base + PLL_CONFIGURATION4);
563 
564 	writel_relaxed(1, base + PLL_GO);	/* PLL_GO */
565 
566 	if (wait_for_bit_change(base + PLL_GO, 0, 0) != 0) {
567 		DSSERR("DSS DPLL GO bit not going down.\n");
568 		return -EIO;
569 	}
570 
571 	if (wait_for_bit_change(base + PLL_STATUS, 1, 1) != 1) {
572 		DSSERR("cannot lock DSS DPLL\n");
573 		return -ETIMEDOUT;
574 	}
575 
576 	return 0;
577 }
578