xref: /openbmc/linux/drivers/gpu/drm/omapdrm/dss/pll.c (revision cfbb9be8)
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/clk.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/regulator/consumer.h>
23 #include <linux/sched.h>
24 
25 #include "omapdss.h"
26 #include "dss.h"
27 
28 #define PLL_CONTROL			0x0000
29 #define PLL_STATUS			0x0004
30 #define PLL_GO				0x0008
31 #define PLL_CONFIGURATION1		0x000C
32 #define PLL_CONFIGURATION2		0x0010
33 #define PLL_CONFIGURATION3		0x0014
34 #define PLL_SSC_CONFIGURATION1		0x0018
35 #define PLL_SSC_CONFIGURATION2		0x001C
36 #define PLL_CONFIGURATION4		0x0020
37 
38 static struct dss_pll *dss_plls[4];
39 
40 int dss_pll_register(struct dss_pll *pll)
41 {
42 	int i;
43 
44 	for (i = 0; i < ARRAY_SIZE(dss_plls); ++i) {
45 		if (!dss_plls[i]) {
46 			dss_plls[i] = pll;
47 			return 0;
48 		}
49 	}
50 
51 	return -EBUSY;
52 }
53 
54 void dss_pll_unregister(struct dss_pll *pll)
55 {
56 	int i;
57 
58 	for (i = 0; i < ARRAY_SIZE(dss_plls); ++i) {
59 		if (dss_plls[i] == pll) {
60 			dss_plls[i] = NULL;
61 			return;
62 		}
63 	}
64 }
65 
66 struct dss_pll *dss_pll_find(const char *name)
67 {
68 	int i;
69 
70 	for (i = 0; i < ARRAY_SIZE(dss_plls); ++i) {
71 		if (dss_plls[i] && strcmp(dss_plls[i]->name, name) == 0)
72 			return dss_plls[i];
73 	}
74 
75 	return NULL;
76 }
77 
78 struct dss_pll *dss_pll_find_by_src(enum dss_clk_source src)
79 {
80 	struct dss_pll *pll;
81 
82 	switch (src) {
83 	default:
84 	case DSS_CLK_SRC_FCK:
85 		return NULL;
86 
87 	case DSS_CLK_SRC_HDMI_PLL:
88 		return dss_pll_find("hdmi");
89 
90 	case DSS_CLK_SRC_PLL1_1:
91 	case DSS_CLK_SRC_PLL1_2:
92 	case DSS_CLK_SRC_PLL1_3:
93 		pll = dss_pll_find("dsi0");
94 		if (!pll)
95 			pll = dss_pll_find("video0");
96 		return pll;
97 
98 	case DSS_CLK_SRC_PLL2_1:
99 	case DSS_CLK_SRC_PLL2_2:
100 	case DSS_CLK_SRC_PLL2_3:
101 		pll = dss_pll_find("dsi1");
102 		if (!pll)
103 			pll = dss_pll_find("video1");
104 		return pll;
105 	}
106 }
107 
108 unsigned dss_pll_get_clkout_idx_for_src(enum dss_clk_source src)
109 {
110 	switch (src) {
111 	case DSS_CLK_SRC_HDMI_PLL:
112 		return 0;
113 
114 	case DSS_CLK_SRC_PLL1_1:
115 	case DSS_CLK_SRC_PLL2_1:
116 		return 0;
117 
118 	case DSS_CLK_SRC_PLL1_2:
119 	case DSS_CLK_SRC_PLL2_2:
120 		return 1;
121 
122 	case DSS_CLK_SRC_PLL1_3:
123 	case DSS_CLK_SRC_PLL2_3:
124 		return 2;
125 
126 	default:
127 		return 0;
128 	}
129 }
130 
131 int dss_pll_enable(struct dss_pll *pll)
132 {
133 	int r;
134 
135 	r = clk_prepare_enable(pll->clkin);
136 	if (r)
137 		return r;
138 
139 	if (pll->regulator) {
140 		r = regulator_enable(pll->regulator);
141 		if (r)
142 			goto err_reg;
143 	}
144 
145 	r = pll->ops->enable(pll);
146 	if (r)
147 		goto err_enable;
148 
149 	return 0;
150 
151 err_enable:
152 	if (pll->regulator)
153 		regulator_disable(pll->regulator);
154 err_reg:
155 	clk_disable_unprepare(pll->clkin);
156 	return r;
157 }
158 
159 void dss_pll_disable(struct dss_pll *pll)
160 {
161 	pll->ops->disable(pll);
162 
163 	if (pll->regulator)
164 		regulator_disable(pll->regulator);
165 
166 	clk_disable_unprepare(pll->clkin);
167 
168 	memset(&pll->cinfo, 0, sizeof(pll->cinfo));
169 }
170 
171 int dss_pll_set_config(struct dss_pll *pll, const struct dss_pll_clock_info *cinfo)
172 {
173 	int r;
174 
175 	r = pll->ops->set_config(pll, cinfo);
176 	if (r)
177 		return r;
178 
179 	pll->cinfo = *cinfo;
180 
181 	return 0;
182 }
183 
184 bool dss_pll_hsdiv_calc_a(const struct dss_pll *pll, unsigned long clkdco,
185 		unsigned long out_min, unsigned long out_max,
186 		dss_hsdiv_calc_func func, void *data)
187 {
188 	const struct dss_pll_hw *hw = pll->hw;
189 	int m, m_start, m_stop;
190 	unsigned long out;
191 
192 	out_min = out_min ? out_min : 1;
193 	out_max = out_max ? out_max : ULONG_MAX;
194 
195 	m_start = max(DIV_ROUND_UP(clkdco, out_max), 1ul);
196 
197 	m_stop = min((unsigned)(clkdco / out_min), hw->mX_max);
198 
199 	for (m = m_start; m <= m_stop; ++m) {
200 		out = clkdco / m;
201 
202 		if (func(m, out, data))
203 			return true;
204 	}
205 
206 	return false;
207 }
208 
209 /*
210  * clkdco = clkin / n * m * 2
211  * clkoutX = clkdco / mX
212  */
213 bool dss_pll_calc_a(const struct dss_pll *pll, unsigned long clkin,
214 		unsigned long pll_min, unsigned long pll_max,
215 		dss_pll_calc_func func, void *data)
216 {
217 	const struct dss_pll_hw *hw = pll->hw;
218 	int n, n_start, n_stop, n_inc;
219 	int m, m_start, m_stop, m_inc;
220 	unsigned long fint, clkdco;
221 	unsigned long pll_hw_max;
222 	unsigned long fint_hw_min, fint_hw_max;
223 
224 	pll_hw_max = hw->clkdco_max;
225 
226 	fint_hw_min = hw->fint_min;
227 	fint_hw_max = hw->fint_max;
228 
229 	n_start = max(DIV_ROUND_UP(clkin, fint_hw_max), 1ul);
230 	n_stop = min((unsigned)(clkin / fint_hw_min), hw->n_max);
231 	n_inc = 1;
232 
233 	if (hw->errata_i886) {
234 		swap(n_start, n_stop);
235 		n_inc = -1;
236 	}
237 
238 	pll_max = pll_max ? pll_max : ULONG_MAX;
239 
240 	for (n = n_start; n != n_stop; n += n_inc) {
241 		fint = clkin / n;
242 
243 		m_start = max(DIV_ROUND_UP(DIV_ROUND_UP(pll_min, fint), 2),
244 				1ul);
245 		m_stop = min3((unsigned)(pll_max / fint / 2),
246 				(unsigned)(pll_hw_max / fint / 2),
247 				hw->m_max);
248 		m_inc = 1;
249 
250 		if (hw->errata_i886) {
251 			swap(m_start, m_stop);
252 			m_inc = -1;
253 		}
254 
255 		for (m = m_start; m != m_stop; m += m_inc) {
256 			clkdco = 2 * m * fint;
257 
258 			if (func(n, m, fint, clkdco, data))
259 				return true;
260 		}
261 	}
262 
263 	return false;
264 }
265 
266 /*
267  * This calculates a PLL config that will provide the target_clkout rate
268  * for clkout. Additionally clkdco rate will be the same as clkout rate
269  * when clkout rate is >= min_clkdco.
270  *
271  * clkdco = clkin / n * m + clkin / n * mf / 262144
272  * clkout = clkdco / m2
273  */
274 bool dss_pll_calc_b(const struct dss_pll *pll, unsigned long clkin,
275 	unsigned long target_clkout, struct dss_pll_clock_info *cinfo)
276 {
277 	unsigned long fint, clkdco, clkout;
278 	unsigned long target_clkdco;
279 	unsigned long min_dco;
280 	unsigned n, m, mf, m2, sd;
281 	const struct dss_pll_hw *hw = pll->hw;
282 
283 	DSSDBG("clkin %lu, target clkout %lu\n", clkin, target_clkout);
284 
285 	/* Fint */
286 	n = DIV_ROUND_UP(clkin, hw->fint_max);
287 	fint = clkin / n;
288 
289 	/* adjust m2 so that the clkdco will be high enough */
290 	min_dco = roundup(hw->clkdco_min, fint);
291 	m2 = DIV_ROUND_UP(min_dco, target_clkout);
292 	if (m2 == 0)
293 		m2 = 1;
294 
295 	target_clkdco = target_clkout * m2;
296 	m = target_clkdco / fint;
297 
298 	clkdco = fint * m;
299 
300 	/* adjust clkdco with fractional mf */
301 	if (WARN_ON(target_clkdco - clkdco > fint))
302 		mf = 0;
303 	else
304 		mf = (u32)div_u64(262144ull * (target_clkdco - clkdco), fint);
305 
306 	if (mf > 0)
307 		clkdco += (u32)div_u64((u64)mf * fint, 262144);
308 
309 	clkout = clkdco / m2;
310 
311 	/* sigma-delta */
312 	sd = DIV_ROUND_UP(fint * m, 250000000);
313 
314 	DSSDBG("N = %u, M = %u, M.f = %u, M2 = %u, SD = %u\n",
315 		n, m, mf, m2, sd);
316 	DSSDBG("Fint %lu, clkdco %lu, clkout %lu\n", fint, clkdco, clkout);
317 
318 	cinfo->n = n;
319 	cinfo->m = m;
320 	cinfo->mf = mf;
321 	cinfo->mX[0] = m2;
322 	cinfo->sd = sd;
323 
324 	cinfo->fint = fint;
325 	cinfo->clkdco = clkdco;
326 	cinfo->clkout[0] = clkout;
327 
328 	return true;
329 }
330 
331 static int wait_for_bit_change(void __iomem *reg, int bitnum, int value)
332 {
333 	unsigned long timeout;
334 	ktime_t wait;
335 	int t;
336 
337 	/* first busyloop to see if the bit changes right away */
338 	t = 100;
339 	while (t-- > 0) {
340 		if (FLD_GET(readl_relaxed(reg), bitnum, bitnum) == value)
341 			return value;
342 	}
343 
344 	/* then loop for 500ms, sleeping for 1ms in between */
345 	timeout = jiffies + msecs_to_jiffies(500);
346 	while (time_before(jiffies, timeout)) {
347 		if (FLD_GET(readl_relaxed(reg), bitnum, bitnum) == value)
348 			return value;
349 
350 		wait = ns_to_ktime(1000 * 1000);
351 		set_current_state(TASK_UNINTERRUPTIBLE);
352 		schedule_hrtimeout(&wait, HRTIMER_MODE_REL);
353 	}
354 
355 	return !value;
356 }
357 
358 int dss_pll_wait_reset_done(struct dss_pll *pll)
359 {
360 	void __iomem *base = pll->base;
361 
362 	if (wait_for_bit_change(base + PLL_STATUS, 0, 1) != 1)
363 		return -ETIMEDOUT;
364 	else
365 		return 0;
366 }
367 
368 static int dss_wait_hsdiv_ack(struct dss_pll *pll, u32 hsdiv_ack_mask)
369 {
370 	int t = 100;
371 
372 	while (t-- > 0) {
373 		u32 v = readl_relaxed(pll->base + PLL_STATUS);
374 		v &= hsdiv_ack_mask;
375 		if (v == hsdiv_ack_mask)
376 			return 0;
377 	}
378 
379 	return -ETIMEDOUT;
380 }
381 
382 int dss_pll_write_config_type_a(struct dss_pll *pll,
383 		const struct dss_pll_clock_info *cinfo)
384 {
385 	const struct dss_pll_hw *hw = pll->hw;
386 	void __iomem *base = pll->base;
387 	int r = 0;
388 	u32 l;
389 
390 	l = 0;
391 	if (hw->has_stopmode)
392 		l = FLD_MOD(l, 1, 0, 0);		/* PLL_STOPMODE */
393 	l = FLD_MOD(l, cinfo->n - 1, hw->n_msb, hw->n_lsb);	/* PLL_REGN */
394 	l = FLD_MOD(l, cinfo->m, hw->m_msb, hw->m_lsb);		/* PLL_REGM */
395 	/* M4 */
396 	l = FLD_MOD(l, cinfo->mX[0] ? cinfo->mX[0] - 1 : 0,
397 			hw->mX_msb[0], hw->mX_lsb[0]);
398 	/* M5 */
399 	l = FLD_MOD(l, cinfo->mX[1] ? cinfo->mX[1] - 1 : 0,
400 			hw->mX_msb[1], hw->mX_lsb[1]);
401 	writel_relaxed(l, base + PLL_CONFIGURATION1);
402 
403 	l = 0;
404 	/* M6 */
405 	l = FLD_MOD(l, cinfo->mX[2] ? cinfo->mX[2] - 1 : 0,
406 			hw->mX_msb[2], hw->mX_lsb[2]);
407 	/* M7 */
408 	l = FLD_MOD(l, cinfo->mX[3] ? cinfo->mX[3] - 1 : 0,
409 			hw->mX_msb[3], hw->mX_lsb[3]);
410 	writel_relaxed(l, base + PLL_CONFIGURATION3);
411 
412 	l = readl_relaxed(base + PLL_CONFIGURATION2);
413 	if (hw->has_freqsel) {
414 		u32 f = cinfo->fint < 1000000 ? 0x3 :
415 			cinfo->fint < 1250000 ? 0x4 :
416 			cinfo->fint < 1500000 ? 0x5 :
417 			cinfo->fint < 1750000 ? 0x6 :
418 			0x7;
419 
420 		l = FLD_MOD(l, f, 4, 1);	/* PLL_FREQSEL */
421 	} else if (hw->has_selfreqdco) {
422 		u32 f = cinfo->clkdco < hw->clkdco_low ? 0x2 : 0x4;
423 
424 		l = FLD_MOD(l, f, 3, 1);	/* PLL_SELFREQDCO */
425 	}
426 	l = FLD_MOD(l, 1, 13, 13);		/* PLL_REFEN */
427 	l = FLD_MOD(l, 0, 14, 14);		/* PHY_CLKINEN */
428 	l = FLD_MOD(l, 0, 16, 16);		/* M4_CLOCK_EN */
429 	l = FLD_MOD(l, 0, 18, 18);		/* M5_CLOCK_EN */
430 	l = FLD_MOD(l, 1, 20, 20);		/* HSDIVBYPASS */
431 	if (hw->has_refsel)
432 		l = FLD_MOD(l, 3, 22, 21);	/* REFSEL = sysclk */
433 	l = FLD_MOD(l, 0, 23, 23);		/* M6_CLOCK_EN */
434 	l = FLD_MOD(l, 0, 25, 25);		/* M7_CLOCK_EN */
435 	writel_relaxed(l, base + PLL_CONFIGURATION2);
436 
437 	writel_relaxed(1, base + PLL_GO);	/* PLL_GO */
438 
439 	if (wait_for_bit_change(base + PLL_GO, 0, 0) != 0) {
440 		DSSERR("DSS DPLL GO bit not going down.\n");
441 		r = -EIO;
442 		goto err;
443 	}
444 
445 	if (wait_for_bit_change(base + PLL_STATUS, 1, 1) != 1) {
446 		DSSERR("cannot lock DSS DPLL\n");
447 		r = -EIO;
448 		goto err;
449 	}
450 
451 	l = readl_relaxed(base + PLL_CONFIGURATION2);
452 	l = FLD_MOD(l, 1, 14, 14);			/* PHY_CLKINEN */
453 	l = FLD_MOD(l, cinfo->mX[0] ? 1 : 0, 16, 16);	/* M4_CLOCK_EN */
454 	l = FLD_MOD(l, cinfo->mX[1] ? 1 : 0, 18, 18);	/* M5_CLOCK_EN */
455 	l = FLD_MOD(l, 0, 20, 20);			/* HSDIVBYPASS */
456 	l = FLD_MOD(l, cinfo->mX[2] ? 1 : 0, 23, 23);	/* M6_CLOCK_EN */
457 	l = FLD_MOD(l, cinfo->mX[3] ? 1 : 0, 25, 25);	/* M7_CLOCK_EN */
458 	writel_relaxed(l, base + PLL_CONFIGURATION2);
459 
460 	r = dss_wait_hsdiv_ack(pll,
461 		(cinfo->mX[0] ? BIT(7) : 0) |
462 		(cinfo->mX[1] ? BIT(8) : 0) |
463 		(cinfo->mX[2] ? BIT(10) : 0) |
464 		(cinfo->mX[3] ? BIT(11) : 0));
465 	if (r) {
466 		DSSERR("failed to enable HSDIV clocks\n");
467 		goto err;
468 	}
469 
470 err:
471 	return r;
472 }
473 
474 int dss_pll_write_config_type_b(struct dss_pll *pll,
475 		const struct dss_pll_clock_info *cinfo)
476 {
477 	const struct dss_pll_hw *hw = pll->hw;
478 	void __iomem *base = pll->base;
479 	u32 l;
480 
481 	l = 0;
482 	l = FLD_MOD(l, cinfo->m, 20, 9);	/* PLL_REGM */
483 	l = FLD_MOD(l, cinfo->n - 1, 8, 1);	/* PLL_REGN */
484 	writel_relaxed(l, base + PLL_CONFIGURATION1);
485 
486 	l = readl_relaxed(base + PLL_CONFIGURATION2);
487 	l = FLD_MOD(l, 0x0, 12, 12);	/* PLL_HIGHFREQ divide by 2 */
488 	l = FLD_MOD(l, 0x1, 13, 13);	/* PLL_REFEN */
489 	l = FLD_MOD(l, 0x0, 14, 14);	/* PHY_CLKINEN */
490 	if (hw->has_refsel)
491 		l = FLD_MOD(l, 0x3, 22, 21);	/* REFSEL = SYSCLK */
492 
493 	/* PLL_SELFREQDCO */
494 	if (cinfo->clkdco > hw->clkdco_low)
495 		l = FLD_MOD(l, 0x4, 3, 1);
496 	else
497 		l = FLD_MOD(l, 0x2, 3, 1);
498 	writel_relaxed(l, base + PLL_CONFIGURATION2);
499 
500 	l = readl_relaxed(base + PLL_CONFIGURATION3);
501 	l = FLD_MOD(l, cinfo->sd, 17, 10);	/* PLL_REGSD */
502 	writel_relaxed(l, base + PLL_CONFIGURATION3);
503 
504 	l = readl_relaxed(base + PLL_CONFIGURATION4);
505 	l = FLD_MOD(l, cinfo->mX[0], 24, 18);	/* PLL_REGM2 */
506 	l = FLD_MOD(l, cinfo->mf, 17, 0);	/* PLL_REGM_F */
507 	writel_relaxed(l, base + PLL_CONFIGURATION4);
508 
509 	writel_relaxed(1, base + PLL_GO);	/* PLL_GO */
510 
511 	if (wait_for_bit_change(base + PLL_GO, 0, 0) != 0) {
512 		DSSERR("DSS DPLL GO bit not going down.\n");
513 		return -EIO;
514 	}
515 
516 	if (wait_for_bit_change(base + PLL_STATUS, 1, 1) != 1) {
517 		DSSERR("cannot lock DSS DPLL\n");
518 		return -ETIMEDOUT;
519 	}
520 
521 	return 0;
522 }
523