xref: /openbmc/linux/drivers/gpu/drm/omapdrm/dss/pll.c (revision 84b102f5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014 Texas Instruments Incorporated - https://www.ti.com/
4  */
5 
6 #define DSS_SUBSYS_NAME "PLL"
7 
8 #include <linux/delay.h>
9 #include <linux/clk.h>
10 #include <linux/io.h>
11 #include <linux/kernel.h>
12 #include <linux/regulator/consumer.h>
13 #include <linux/sched.h>
14 
15 #include "omapdss.h"
16 #include "dss.h"
17 
18 #define PLL_CONTROL			0x0000
19 #define PLL_STATUS			0x0004
20 #define PLL_GO				0x0008
21 #define PLL_CONFIGURATION1		0x000C
22 #define PLL_CONFIGURATION2		0x0010
23 #define PLL_CONFIGURATION3		0x0014
24 #define PLL_SSC_CONFIGURATION1		0x0018
25 #define PLL_SSC_CONFIGURATION2		0x001C
26 #define PLL_CONFIGURATION4		0x0020
27 
28 int dss_pll_register(struct dss_device *dss, struct dss_pll *pll)
29 {
30 	int i;
31 
32 	for (i = 0; i < ARRAY_SIZE(dss->plls); ++i) {
33 		if (!dss->plls[i]) {
34 			dss->plls[i] = pll;
35 			pll->dss = dss;
36 			return 0;
37 		}
38 	}
39 
40 	return -EBUSY;
41 }
42 
43 void dss_pll_unregister(struct dss_pll *pll)
44 {
45 	struct dss_device *dss = pll->dss;
46 	int i;
47 
48 	for (i = 0; i < ARRAY_SIZE(dss->plls); ++i) {
49 		if (dss->plls[i] == pll) {
50 			dss->plls[i] = NULL;
51 			pll->dss = NULL;
52 			return;
53 		}
54 	}
55 }
56 
57 struct dss_pll *dss_pll_find(struct dss_device *dss, const char *name)
58 {
59 	int i;
60 
61 	for (i = 0; i < ARRAY_SIZE(dss->plls); ++i) {
62 		if (dss->plls[i] && strcmp(dss->plls[i]->name, name) == 0)
63 			return dss->plls[i];
64 	}
65 
66 	return NULL;
67 }
68 
69 struct dss_pll *dss_pll_find_by_src(struct dss_device *dss,
70 				    enum dss_clk_source src)
71 {
72 	struct dss_pll *pll;
73 
74 	switch (src) {
75 	default:
76 	case DSS_CLK_SRC_FCK:
77 		return NULL;
78 
79 	case DSS_CLK_SRC_HDMI_PLL:
80 		return dss_pll_find(dss, "hdmi");
81 
82 	case DSS_CLK_SRC_PLL1_1:
83 	case DSS_CLK_SRC_PLL1_2:
84 	case DSS_CLK_SRC_PLL1_3:
85 		pll = dss_pll_find(dss, "dsi0");
86 		if (!pll)
87 			pll = dss_pll_find(dss, "video0");
88 		return pll;
89 
90 	case DSS_CLK_SRC_PLL2_1:
91 	case DSS_CLK_SRC_PLL2_2:
92 	case DSS_CLK_SRC_PLL2_3:
93 		pll = dss_pll_find(dss, "dsi1");
94 		if (!pll)
95 			pll = dss_pll_find(dss, "video1");
96 		return pll;
97 	}
98 }
99 
100 unsigned int dss_pll_get_clkout_idx_for_src(enum dss_clk_source src)
101 {
102 	switch (src) {
103 	case DSS_CLK_SRC_HDMI_PLL:
104 		return 0;
105 
106 	case DSS_CLK_SRC_PLL1_1:
107 	case DSS_CLK_SRC_PLL2_1:
108 		return 0;
109 
110 	case DSS_CLK_SRC_PLL1_2:
111 	case DSS_CLK_SRC_PLL2_2:
112 		return 1;
113 
114 	case DSS_CLK_SRC_PLL1_3:
115 	case DSS_CLK_SRC_PLL2_3:
116 		return 2;
117 
118 	default:
119 		return 0;
120 	}
121 }
122 
123 int dss_pll_enable(struct dss_pll *pll)
124 {
125 	int r;
126 
127 	r = clk_prepare_enable(pll->clkin);
128 	if (r)
129 		return r;
130 
131 	if (pll->regulator) {
132 		r = regulator_enable(pll->regulator);
133 		if (r)
134 			goto err_reg;
135 	}
136 
137 	r = pll->ops->enable(pll);
138 	if (r)
139 		goto err_enable;
140 
141 	return 0;
142 
143 err_enable:
144 	if (pll->regulator)
145 		regulator_disable(pll->regulator);
146 err_reg:
147 	clk_disable_unprepare(pll->clkin);
148 	return r;
149 }
150 
151 void dss_pll_disable(struct dss_pll *pll)
152 {
153 	pll->ops->disable(pll);
154 
155 	if (pll->regulator)
156 		regulator_disable(pll->regulator);
157 
158 	clk_disable_unprepare(pll->clkin);
159 
160 	memset(&pll->cinfo, 0, sizeof(pll->cinfo));
161 }
162 
163 int dss_pll_set_config(struct dss_pll *pll, const struct dss_pll_clock_info *cinfo)
164 {
165 	int r;
166 
167 	r = pll->ops->set_config(pll, cinfo);
168 	if (r)
169 		return r;
170 
171 	pll->cinfo = *cinfo;
172 
173 	return 0;
174 }
175 
176 bool dss_pll_hsdiv_calc_a(const struct dss_pll *pll, unsigned long clkdco,
177 		unsigned long out_min, unsigned long out_max,
178 		dss_hsdiv_calc_func func, void *data)
179 {
180 	const struct dss_pll_hw *hw = pll->hw;
181 	int m, m_start, m_stop;
182 	unsigned long out;
183 
184 	out_min = out_min ? out_min : 1;
185 	out_max = out_max ? out_max : ULONG_MAX;
186 
187 	m_start = max(DIV_ROUND_UP(clkdco, out_max), 1ul);
188 
189 	m_stop = min((unsigned)(clkdco / out_min), hw->mX_max);
190 
191 	for (m = m_start; m <= m_stop; ++m) {
192 		out = clkdco / m;
193 
194 		if (func(m, out, data))
195 			return true;
196 	}
197 
198 	return false;
199 }
200 
201 /*
202  * clkdco = clkin / n * m * 2
203  * clkoutX = clkdco / mX
204  */
205 bool dss_pll_calc_a(const struct dss_pll *pll, unsigned long clkin,
206 		unsigned long pll_min, unsigned long pll_max,
207 		dss_pll_calc_func func, void *data)
208 {
209 	const struct dss_pll_hw *hw = pll->hw;
210 	int n, n_start, n_stop, n_inc;
211 	int m, m_start, m_stop, m_inc;
212 	unsigned long fint, clkdco;
213 	unsigned long pll_hw_max;
214 	unsigned long fint_hw_min, fint_hw_max;
215 
216 	pll_hw_max = hw->clkdco_max;
217 
218 	fint_hw_min = hw->fint_min;
219 	fint_hw_max = hw->fint_max;
220 
221 	n_start = max(DIV_ROUND_UP(clkin, fint_hw_max), 1ul);
222 	n_stop = min((unsigned)(clkin / fint_hw_min), hw->n_max);
223 	n_inc = 1;
224 
225 	if (hw->errata_i886) {
226 		swap(n_start, n_stop);
227 		n_inc = -1;
228 	}
229 
230 	pll_max = pll_max ? pll_max : ULONG_MAX;
231 
232 	for (n = n_start; n != n_stop; n += n_inc) {
233 		fint = clkin / n;
234 
235 		m_start = max(DIV_ROUND_UP(DIV_ROUND_UP(pll_min, fint), 2),
236 				1ul);
237 		m_stop = min3((unsigned)(pll_max / fint / 2),
238 				(unsigned)(pll_hw_max / fint / 2),
239 				hw->m_max);
240 		m_inc = 1;
241 
242 		if (hw->errata_i886) {
243 			swap(m_start, m_stop);
244 			m_inc = -1;
245 		}
246 
247 		for (m = m_start; m != m_stop; m += m_inc) {
248 			clkdco = 2 * m * fint;
249 
250 			if (func(n, m, fint, clkdco, data))
251 				return true;
252 		}
253 	}
254 
255 	return false;
256 }
257 
258 /*
259  * This calculates a PLL config that will provide the target_clkout rate
260  * for clkout. Additionally clkdco rate will be the same as clkout rate
261  * when clkout rate is >= min_clkdco.
262  *
263  * clkdco = clkin / n * m + clkin / n * mf / 262144
264  * clkout = clkdco / m2
265  */
266 bool dss_pll_calc_b(const struct dss_pll *pll, unsigned long clkin,
267 	unsigned long target_clkout, struct dss_pll_clock_info *cinfo)
268 {
269 	unsigned long fint, clkdco, clkout;
270 	unsigned long target_clkdco;
271 	unsigned long min_dco;
272 	unsigned int n, m, mf, m2, sd;
273 	const struct dss_pll_hw *hw = pll->hw;
274 
275 	DSSDBG("clkin %lu, target clkout %lu\n", clkin, target_clkout);
276 
277 	/* Fint */
278 	n = DIV_ROUND_UP(clkin, hw->fint_max);
279 	fint = clkin / n;
280 
281 	/* adjust m2 so that the clkdco will be high enough */
282 	min_dco = roundup(hw->clkdco_min, fint);
283 	m2 = DIV_ROUND_UP(min_dco, target_clkout);
284 	if (m2 == 0)
285 		m2 = 1;
286 
287 	target_clkdco = target_clkout * m2;
288 	m = target_clkdco / fint;
289 
290 	clkdco = fint * m;
291 
292 	/* adjust clkdco with fractional mf */
293 	if (WARN_ON(target_clkdco - clkdco > fint))
294 		mf = 0;
295 	else
296 		mf = (u32)div_u64(262144ull * (target_clkdco - clkdco), fint);
297 
298 	if (mf > 0)
299 		clkdco += (u32)div_u64((u64)mf * fint, 262144);
300 
301 	clkout = clkdco / m2;
302 
303 	/* sigma-delta */
304 	sd = DIV_ROUND_UP(fint * m, 250000000);
305 
306 	DSSDBG("N = %u, M = %u, M.f = %u, M2 = %u, SD = %u\n",
307 		n, m, mf, m2, sd);
308 	DSSDBG("Fint %lu, clkdco %lu, clkout %lu\n", fint, clkdco, clkout);
309 
310 	cinfo->n = n;
311 	cinfo->m = m;
312 	cinfo->mf = mf;
313 	cinfo->mX[0] = m2;
314 	cinfo->sd = sd;
315 
316 	cinfo->fint = fint;
317 	cinfo->clkdco = clkdco;
318 	cinfo->clkout[0] = clkout;
319 
320 	return true;
321 }
322 
323 static int wait_for_bit_change(void __iomem *reg, int bitnum, int value)
324 {
325 	unsigned long timeout;
326 	ktime_t wait;
327 	int t;
328 
329 	/* first busyloop to see if the bit changes right away */
330 	t = 100;
331 	while (t-- > 0) {
332 		if (FLD_GET(readl_relaxed(reg), bitnum, bitnum) == value)
333 			return value;
334 	}
335 
336 	/* then loop for 500ms, sleeping for 1ms in between */
337 	timeout = jiffies + msecs_to_jiffies(500);
338 	while (time_before(jiffies, timeout)) {
339 		if (FLD_GET(readl_relaxed(reg), bitnum, bitnum) == value)
340 			return value;
341 
342 		wait = ns_to_ktime(1000 * 1000);
343 		set_current_state(TASK_UNINTERRUPTIBLE);
344 		schedule_hrtimeout(&wait, HRTIMER_MODE_REL);
345 	}
346 
347 	return !value;
348 }
349 
350 int dss_pll_wait_reset_done(struct dss_pll *pll)
351 {
352 	void __iomem *base = pll->base;
353 
354 	if (wait_for_bit_change(base + PLL_STATUS, 0, 1) != 1)
355 		return -ETIMEDOUT;
356 	else
357 		return 0;
358 }
359 
360 static int dss_wait_hsdiv_ack(struct dss_pll *pll, u32 hsdiv_ack_mask)
361 {
362 	int t = 100;
363 
364 	while (t-- > 0) {
365 		u32 v = readl_relaxed(pll->base + PLL_STATUS);
366 		v &= hsdiv_ack_mask;
367 		if (v == hsdiv_ack_mask)
368 			return 0;
369 	}
370 
371 	return -ETIMEDOUT;
372 }
373 
374 static bool pll_is_locked(u32 stat)
375 {
376 	/*
377 	 * Required value for each bitfield listed below
378 	 *
379 	 * PLL_STATUS[6] = 0  PLL_BYPASS
380 	 * PLL_STATUS[5] = 0  PLL_HIGHJITTER
381 	 *
382 	 * PLL_STATUS[3] = 0  PLL_LOSSREF
383 	 * PLL_STATUS[2] = 0  PLL_RECAL
384 	 * PLL_STATUS[1] = 1  PLL_LOCK
385 	 * PLL_STATUS[0] = 1  PLL_CTRL_RESET_DONE
386 	 */
387 	return ((stat & 0x6f) == 0x3);
388 }
389 
390 int dss_pll_write_config_type_a(struct dss_pll *pll,
391 		const struct dss_pll_clock_info *cinfo)
392 {
393 	const struct dss_pll_hw *hw = pll->hw;
394 	void __iomem *base = pll->base;
395 	int r = 0;
396 	u32 l;
397 
398 	l = 0;
399 	if (hw->has_stopmode)
400 		l = FLD_MOD(l, 1, 0, 0);		/* PLL_STOPMODE */
401 	l = FLD_MOD(l, cinfo->n - 1, hw->n_msb, hw->n_lsb);	/* PLL_REGN */
402 	l = FLD_MOD(l, cinfo->m, hw->m_msb, hw->m_lsb);		/* PLL_REGM */
403 	/* M4 */
404 	l = FLD_MOD(l, cinfo->mX[0] ? cinfo->mX[0] - 1 : 0,
405 			hw->mX_msb[0], hw->mX_lsb[0]);
406 	/* M5 */
407 	l = FLD_MOD(l, cinfo->mX[1] ? cinfo->mX[1] - 1 : 0,
408 			hw->mX_msb[1], hw->mX_lsb[1]);
409 	writel_relaxed(l, base + PLL_CONFIGURATION1);
410 
411 	l = 0;
412 	/* M6 */
413 	l = FLD_MOD(l, cinfo->mX[2] ? cinfo->mX[2] - 1 : 0,
414 			hw->mX_msb[2], hw->mX_lsb[2]);
415 	/* M7 */
416 	l = FLD_MOD(l, cinfo->mX[3] ? cinfo->mX[3] - 1 : 0,
417 			hw->mX_msb[3], hw->mX_lsb[3]);
418 	writel_relaxed(l, base + PLL_CONFIGURATION3);
419 
420 	l = readl_relaxed(base + PLL_CONFIGURATION2);
421 	if (hw->has_freqsel) {
422 		u32 f = cinfo->fint < 1000000 ? 0x3 :
423 			cinfo->fint < 1250000 ? 0x4 :
424 			cinfo->fint < 1500000 ? 0x5 :
425 			cinfo->fint < 1750000 ? 0x6 :
426 			0x7;
427 
428 		l = FLD_MOD(l, f, 4, 1);	/* PLL_FREQSEL */
429 	} else if (hw->has_selfreqdco) {
430 		u32 f = cinfo->clkdco < hw->clkdco_low ? 0x2 : 0x4;
431 
432 		l = FLD_MOD(l, f, 3, 1);	/* PLL_SELFREQDCO */
433 	}
434 	l = FLD_MOD(l, 1, 13, 13);		/* PLL_REFEN */
435 	l = FLD_MOD(l, 0, 14, 14);		/* PHY_CLKINEN */
436 	l = FLD_MOD(l, 0, 16, 16);		/* M4_CLOCK_EN */
437 	l = FLD_MOD(l, 0, 18, 18);		/* M5_CLOCK_EN */
438 	l = FLD_MOD(l, 1, 20, 20);		/* HSDIVBYPASS */
439 	if (hw->has_refsel)
440 		l = FLD_MOD(l, 3, 22, 21);	/* REFSEL = sysclk */
441 	l = FLD_MOD(l, 0, 23, 23);		/* M6_CLOCK_EN */
442 	l = FLD_MOD(l, 0, 25, 25);		/* M7_CLOCK_EN */
443 	writel_relaxed(l, base + PLL_CONFIGURATION2);
444 
445 	if (hw->errata_i932) {
446 		int cnt = 0;
447 		u32 sleep_time;
448 		const u32 max_lock_retries = 20;
449 
450 		/*
451 		 * Calculate wait time for PLL LOCK
452 		 * 1000 REFCLK cycles in us.
453 		 */
454 		sleep_time = DIV_ROUND_UP(1000*1000*1000, cinfo->fint);
455 
456 		for (cnt = 0; cnt < max_lock_retries; cnt++) {
457 			writel_relaxed(1, base + PLL_GO);	/* PLL_GO */
458 
459 			/**
460 			 * read the register back to ensure the write is
461 			 * flushed
462 			 */
463 			readl_relaxed(base + PLL_GO);
464 
465 			usleep_range(sleep_time, sleep_time + 5);
466 			l = readl_relaxed(base + PLL_STATUS);
467 
468 			if (pll_is_locked(l) &&
469 			    !(readl_relaxed(base + PLL_GO) & 0x1))
470 				break;
471 
472 		}
473 
474 		if (cnt == max_lock_retries) {
475 			DSSERR("cannot lock PLL\n");
476 			r = -EIO;
477 			goto err;
478 		}
479 	} else {
480 		writel_relaxed(1, base + PLL_GO);	/* PLL_GO */
481 
482 		if (wait_for_bit_change(base + PLL_GO, 0, 0) != 0) {
483 			DSSERR("DSS DPLL GO bit not going down.\n");
484 			r = -EIO;
485 			goto err;
486 		}
487 
488 		if (wait_for_bit_change(base + PLL_STATUS, 1, 1) != 1) {
489 			DSSERR("cannot lock DSS DPLL\n");
490 			r = -EIO;
491 			goto err;
492 		}
493 	}
494 
495 	l = readl_relaxed(base + PLL_CONFIGURATION2);
496 	l = FLD_MOD(l, 1, 14, 14);			/* PHY_CLKINEN */
497 	l = FLD_MOD(l, cinfo->mX[0] ? 1 : 0, 16, 16);	/* M4_CLOCK_EN */
498 	l = FLD_MOD(l, cinfo->mX[1] ? 1 : 0, 18, 18);	/* M5_CLOCK_EN */
499 	l = FLD_MOD(l, 0, 20, 20);			/* HSDIVBYPASS */
500 	l = FLD_MOD(l, cinfo->mX[2] ? 1 : 0, 23, 23);	/* M6_CLOCK_EN */
501 	l = FLD_MOD(l, cinfo->mX[3] ? 1 : 0, 25, 25);	/* M7_CLOCK_EN */
502 	writel_relaxed(l, base + PLL_CONFIGURATION2);
503 
504 	r = dss_wait_hsdiv_ack(pll,
505 		(cinfo->mX[0] ? BIT(7) : 0) |
506 		(cinfo->mX[1] ? BIT(8) : 0) |
507 		(cinfo->mX[2] ? BIT(10) : 0) |
508 		(cinfo->mX[3] ? BIT(11) : 0));
509 	if (r) {
510 		DSSERR("failed to enable HSDIV clocks\n");
511 		goto err;
512 	}
513 
514 err:
515 	return r;
516 }
517 
518 int dss_pll_write_config_type_b(struct dss_pll *pll,
519 		const struct dss_pll_clock_info *cinfo)
520 {
521 	const struct dss_pll_hw *hw = pll->hw;
522 	void __iomem *base = pll->base;
523 	u32 l;
524 
525 	l = 0;
526 	l = FLD_MOD(l, cinfo->m, 20, 9);	/* PLL_REGM */
527 	l = FLD_MOD(l, cinfo->n - 1, 8, 1);	/* PLL_REGN */
528 	writel_relaxed(l, base + PLL_CONFIGURATION1);
529 
530 	l = readl_relaxed(base + PLL_CONFIGURATION2);
531 	l = FLD_MOD(l, 0x0, 12, 12);	/* PLL_HIGHFREQ divide by 2 */
532 	l = FLD_MOD(l, 0x1, 13, 13);	/* PLL_REFEN */
533 	l = FLD_MOD(l, 0x0, 14, 14);	/* PHY_CLKINEN */
534 	if (hw->has_refsel)
535 		l = FLD_MOD(l, 0x3, 22, 21);	/* REFSEL = SYSCLK */
536 
537 	/* PLL_SELFREQDCO */
538 	if (cinfo->clkdco > hw->clkdco_low)
539 		l = FLD_MOD(l, 0x4, 3, 1);
540 	else
541 		l = FLD_MOD(l, 0x2, 3, 1);
542 	writel_relaxed(l, base + PLL_CONFIGURATION2);
543 
544 	l = readl_relaxed(base + PLL_CONFIGURATION3);
545 	l = FLD_MOD(l, cinfo->sd, 17, 10);	/* PLL_REGSD */
546 	writel_relaxed(l, base + PLL_CONFIGURATION3);
547 
548 	l = readl_relaxed(base + PLL_CONFIGURATION4);
549 	l = FLD_MOD(l, cinfo->mX[0], 24, 18);	/* PLL_REGM2 */
550 	l = FLD_MOD(l, cinfo->mf, 17, 0);	/* PLL_REGM_F */
551 	writel_relaxed(l, base + PLL_CONFIGURATION4);
552 
553 	writel_relaxed(1, base + PLL_GO);	/* PLL_GO */
554 
555 	if (wait_for_bit_change(base + PLL_GO, 0, 0) != 0) {
556 		DSSERR("DSS DPLL GO bit not going down.\n");
557 		return -EIO;
558 	}
559 
560 	if (wait_for_bit_change(base + PLL_STATUS, 1, 1) != 1) {
561 		DSSERR("cannot lock DSS DPLL\n");
562 		return -ETIMEDOUT;
563 	}
564 
565 	return 0;
566 }
567