xref: /openbmc/linux/drivers/gpu/drm/omapdrm/dss/pll.c (revision faa16bc4)
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 int dss_pll_register(struct dss_device *dss, struct dss_pll *pll)
39 {
40 	int i;
41 
42 	for (i = 0; i < ARRAY_SIZE(dss->plls); ++i) {
43 		if (!dss->plls[i]) {
44 			dss->plls[i] = pll;
45 			pll->dss = dss;
46 			return 0;
47 		}
48 	}
49 
50 	return -EBUSY;
51 }
52 
53 void dss_pll_unregister(struct dss_pll *pll)
54 {
55 	struct dss_device *dss = pll->dss;
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 			pll->dss = NULL;
62 			return;
63 		}
64 	}
65 }
66 
67 struct dss_pll *dss_pll_find(struct dss_device *dss, const char *name)
68 {
69 	int i;
70 
71 	for (i = 0; i < ARRAY_SIZE(dss->plls); ++i) {
72 		if (dss->plls[i] && strcmp(dss->plls[i]->name, name) == 0)
73 			return dss->plls[i];
74 	}
75 
76 	return NULL;
77 }
78 
79 struct dss_pll *dss_pll_find_by_src(struct dss_device *dss,
80 				    enum dss_clk_source src)
81 {
82 	struct dss_pll *pll;
83 
84 	switch (src) {
85 	default:
86 	case DSS_CLK_SRC_FCK:
87 		return NULL;
88 
89 	case DSS_CLK_SRC_HDMI_PLL:
90 		return dss_pll_find(dss, "hdmi");
91 
92 	case DSS_CLK_SRC_PLL1_1:
93 	case DSS_CLK_SRC_PLL1_2:
94 	case DSS_CLK_SRC_PLL1_3:
95 		pll = dss_pll_find(dss, "dsi0");
96 		if (!pll)
97 			pll = dss_pll_find(dss, "video0");
98 		return pll;
99 
100 	case DSS_CLK_SRC_PLL2_1:
101 	case DSS_CLK_SRC_PLL2_2:
102 	case DSS_CLK_SRC_PLL2_3:
103 		pll = dss_pll_find(dss, "dsi1");
104 		if (!pll)
105 			pll = dss_pll_find(dss, "video1");
106 		return pll;
107 	}
108 }
109 
110 unsigned int dss_pll_get_clkout_idx_for_src(enum dss_clk_source src)
111 {
112 	switch (src) {
113 	case DSS_CLK_SRC_HDMI_PLL:
114 		return 0;
115 
116 	case DSS_CLK_SRC_PLL1_1:
117 	case DSS_CLK_SRC_PLL2_1:
118 		return 0;
119 
120 	case DSS_CLK_SRC_PLL1_2:
121 	case DSS_CLK_SRC_PLL2_2:
122 		return 1;
123 
124 	case DSS_CLK_SRC_PLL1_3:
125 	case DSS_CLK_SRC_PLL2_3:
126 		return 2;
127 
128 	default:
129 		return 0;
130 	}
131 }
132 
133 int dss_pll_enable(struct dss_pll *pll)
134 {
135 	int r;
136 
137 	r = clk_prepare_enable(pll->clkin);
138 	if (r)
139 		return r;
140 
141 	if (pll->regulator) {
142 		r = regulator_enable(pll->regulator);
143 		if (r)
144 			goto err_reg;
145 	}
146 
147 	r = pll->ops->enable(pll);
148 	if (r)
149 		goto err_enable;
150 
151 	return 0;
152 
153 err_enable:
154 	if (pll->regulator)
155 		regulator_disable(pll->regulator);
156 err_reg:
157 	clk_disable_unprepare(pll->clkin);
158 	return r;
159 }
160 
161 void dss_pll_disable(struct dss_pll *pll)
162 {
163 	pll->ops->disable(pll);
164 
165 	if (pll->regulator)
166 		regulator_disable(pll->regulator);
167 
168 	clk_disable_unprepare(pll->clkin);
169 
170 	memset(&pll->cinfo, 0, sizeof(pll->cinfo));
171 }
172 
173 int dss_pll_set_config(struct dss_pll *pll, const struct dss_pll_clock_info *cinfo)
174 {
175 	int r;
176 
177 	r = pll->ops->set_config(pll, cinfo);
178 	if (r)
179 		return r;
180 
181 	pll->cinfo = *cinfo;
182 
183 	return 0;
184 }
185 
186 bool dss_pll_hsdiv_calc_a(const struct dss_pll *pll, unsigned long clkdco,
187 		unsigned long out_min, unsigned long out_max,
188 		dss_hsdiv_calc_func func, void *data)
189 {
190 	const struct dss_pll_hw *hw = pll->hw;
191 	int m, m_start, m_stop;
192 	unsigned long out;
193 
194 	out_min = out_min ? out_min : 1;
195 	out_max = out_max ? out_max : ULONG_MAX;
196 
197 	m_start = max(DIV_ROUND_UP(clkdco, out_max), 1ul);
198 
199 	m_stop = min((unsigned)(clkdco / out_min), hw->mX_max);
200 
201 	for (m = m_start; m <= m_stop; ++m) {
202 		out = clkdco / m;
203 
204 		if (func(m, out, data))
205 			return true;
206 	}
207 
208 	return false;
209 }
210 
211 /*
212  * clkdco = clkin / n * m * 2
213  * clkoutX = clkdco / mX
214  */
215 bool dss_pll_calc_a(const struct dss_pll *pll, unsigned long clkin,
216 		unsigned long pll_min, unsigned long pll_max,
217 		dss_pll_calc_func func, void *data)
218 {
219 	const struct dss_pll_hw *hw = pll->hw;
220 	int n, n_start, n_stop, n_inc;
221 	int m, m_start, m_stop, m_inc;
222 	unsigned long fint, clkdco;
223 	unsigned long pll_hw_max;
224 	unsigned long fint_hw_min, fint_hw_max;
225 
226 	pll_hw_max = hw->clkdco_max;
227 
228 	fint_hw_min = hw->fint_min;
229 	fint_hw_max = hw->fint_max;
230 
231 	n_start = max(DIV_ROUND_UP(clkin, fint_hw_max), 1ul);
232 	n_stop = min((unsigned)(clkin / fint_hw_min), hw->n_max);
233 	n_inc = 1;
234 
235 	if (hw->errata_i886) {
236 		swap(n_start, n_stop);
237 		n_inc = -1;
238 	}
239 
240 	pll_max = pll_max ? pll_max : ULONG_MAX;
241 
242 	for (n = n_start; n != n_stop; n += n_inc) {
243 		fint = clkin / n;
244 
245 		m_start = max(DIV_ROUND_UP(DIV_ROUND_UP(pll_min, fint), 2),
246 				1ul);
247 		m_stop = min3((unsigned)(pll_max / fint / 2),
248 				(unsigned)(pll_hw_max / fint / 2),
249 				hw->m_max);
250 		m_inc = 1;
251 
252 		if (hw->errata_i886) {
253 			swap(m_start, m_stop);
254 			m_inc = -1;
255 		}
256 
257 		for (m = m_start; m != m_stop; m += m_inc) {
258 			clkdco = 2 * m * fint;
259 
260 			if (func(n, m, fint, clkdco, data))
261 				return true;
262 		}
263 	}
264 
265 	return false;
266 }
267 
268 /*
269  * This calculates a PLL config that will provide the target_clkout rate
270  * for clkout. Additionally clkdco rate will be the same as clkout rate
271  * when clkout rate is >= min_clkdco.
272  *
273  * clkdco = clkin / n * m + clkin / n * mf / 262144
274  * clkout = clkdco / m2
275  */
276 bool dss_pll_calc_b(const struct dss_pll *pll, unsigned long clkin,
277 	unsigned long target_clkout, struct dss_pll_clock_info *cinfo)
278 {
279 	unsigned long fint, clkdco, clkout;
280 	unsigned long target_clkdco;
281 	unsigned long min_dco;
282 	unsigned int n, m, mf, m2, sd;
283 	const struct dss_pll_hw *hw = pll->hw;
284 
285 	DSSDBG("clkin %lu, target clkout %lu\n", clkin, target_clkout);
286 
287 	/* Fint */
288 	n = DIV_ROUND_UP(clkin, hw->fint_max);
289 	fint = clkin / n;
290 
291 	/* adjust m2 so that the clkdco will be high enough */
292 	min_dco = roundup(hw->clkdco_min, fint);
293 	m2 = DIV_ROUND_UP(min_dco, target_clkout);
294 	if (m2 == 0)
295 		m2 = 1;
296 
297 	target_clkdco = target_clkout * m2;
298 	m = target_clkdco / fint;
299 
300 	clkdco = fint * m;
301 
302 	/* adjust clkdco with fractional mf */
303 	if (WARN_ON(target_clkdco - clkdco > fint))
304 		mf = 0;
305 	else
306 		mf = (u32)div_u64(262144ull * (target_clkdco - clkdco), fint);
307 
308 	if (mf > 0)
309 		clkdco += (u32)div_u64((u64)mf * fint, 262144);
310 
311 	clkout = clkdco / m2;
312 
313 	/* sigma-delta */
314 	sd = DIV_ROUND_UP(fint * m, 250000000);
315 
316 	DSSDBG("N = %u, M = %u, M.f = %u, M2 = %u, SD = %u\n",
317 		n, m, mf, m2, sd);
318 	DSSDBG("Fint %lu, clkdco %lu, clkout %lu\n", fint, clkdco, clkout);
319 
320 	cinfo->n = n;
321 	cinfo->m = m;
322 	cinfo->mf = mf;
323 	cinfo->mX[0] = m2;
324 	cinfo->sd = sd;
325 
326 	cinfo->fint = fint;
327 	cinfo->clkdco = clkdco;
328 	cinfo->clkout[0] = clkout;
329 
330 	return true;
331 }
332 
333 static int wait_for_bit_change(void __iomem *reg, int bitnum, int value)
334 {
335 	unsigned long timeout;
336 	ktime_t wait;
337 	int t;
338 
339 	/* first busyloop to see if the bit changes right away */
340 	t = 100;
341 	while (t-- > 0) {
342 		if (FLD_GET(readl_relaxed(reg), bitnum, bitnum) == value)
343 			return value;
344 	}
345 
346 	/* then loop for 500ms, sleeping for 1ms in between */
347 	timeout = jiffies + msecs_to_jiffies(500);
348 	while (time_before(jiffies, timeout)) {
349 		if (FLD_GET(readl_relaxed(reg), bitnum, bitnum) == value)
350 			return value;
351 
352 		wait = ns_to_ktime(1000 * 1000);
353 		set_current_state(TASK_UNINTERRUPTIBLE);
354 		schedule_hrtimeout(&wait, HRTIMER_MODE_REL);
355 	}
356 
357 	return !value;
358 }
359 
360 int dss_pll_wait_reset_done(struct dss_pll *pll)
361 {
362 	void __iomem *base = pll->base;
363 
364 	if (wait_for_bit_change(base + PLL_STATUS, 0, 1) != 1)
365 		return -ETIMEDOUT;
366 	else
367 		return 0;
368 }
369 
370 static int dss_wait_hsdiv_ack(struct dss_pll *pll, u32 hsdiv_ack_mask)
371 {
372 	int t = 100;
373 
374 	while (t-- > 0) {
375 		u32 v = readl_relaxed(pll->base + PLL_STATUS);
376 		v &= hsdiv_ack_mask;
377 		if (v == hsdiv_ack_mask)
378 			return 0;
379 	}
380 
381 	return -ETIMEDOUT;
382 }
383 
384 int dss_pll_write_config_type_a(struct dss_pll *pll,
385 		const struct dss_pll_clock_info *cinfo)
386 {
387 	const struct dss_pll_hw *hw = pll->hw;
388 	void __iomem *base = pll->base;
389 	int r = 0;
390 	u32 l;
391 
392 	l = 0;
393 	if (hw->has_stopmode)
394 		l = FLD_MOD(l, 1, 0, 0);		/* PLL_STOPMODE */
395 	l = FLD_MOD(l, cinfo->n - 1, hw->n_msb, hw->n_lsb);	/* PLL_REGN */
396 	l = FLD_MOD(l, cinfo->m, hw->m_msb, hw->m_lsb);		/* PLL_REGM */
397 	/* M4 */
398 	l = FLD_MOD(l, cinfo->mX[0] ? cinfo->mX[0] - 1 : 0,
399 			hw->mX_msb[0], hw->mX_lsb[0]);
400 	/* M5 */
401 	l = FLD_MOD(l, cinfo->mX[1] ? cinfo->mX[1] - 1 : 0,
402 			hw->mX_msb[1], hw->mX_lsb[1]);
403 	writel_relaxed(l, base + PLL_CONFIGURATION1);
404 
405 	l = 0;
406 	/* M6 */
407 	l = FLD_MOD(l, cinfo->mX[2] ? cinfo->mX[2] - 1 : 0,
408 			hw->mX_msb[2], hw->mX_lsb[2]);
409 	/* M7 */
410 	l = FLD_MOD(l, cinfo->mX[3] ? cinfo->mX[3] - 1 : 0,
411 			hw->mX_msb[3], hw->mX_lsb[3]);
412 	writel_relaxed(l, base + PLL_CONFIGURATION3);
413 
414 	l = readl_relaxed(base + PLL_CONFIGURATION2);
415 	if (hw->has_freqsel) {
416 		u32 f = cinfo->fint < 1000000 ? 0x3 :
417 			cinfo->fint < 1250000 ? 0x4 :
418 			cinfo->fint < 1500000 ? 0x5 :
419 			cinfo->fint < 1750000 ? 0x6 :
420 			0x7;
421 
422 		l = FLD_MOD(l, f, 4, 1);	/* PLL_FREQSEL */
423 	} else if (hw->has_selfreqdco) {
424 		u32 f = cinfo->clkdco < hw->clkdco_low ? 0x2 : 0x4;
425 
426 		l = FLD_MOD(l, f, 3, 1);	/* PLL_SELFREQDCO */
427 	}
428 	l = FLD_MOD(l, 1, 13, 13);		/* PLL_REFEN */
429 	l = FLD_MOD(l, 0, 14, 14);		/* PHY_CLKINEN */
430 	l = FLD_MOD(l, 0, 16, 16);		/* M4_CLOCK_EN */
431 	l = FLD_MOD(l, 0, 18, 18);		/* M5_CLOCK_EN */
432 	l = FLD_MOD(l, 1, 20, 20);		/* HSDIVBYPASS */
433 	if (hw->has_refsel)
434 		l = FLD_MOD(l, 3, 22, 21);	/* REFSEL = sysclk */
435 	l = FLD_MOD(l, 0, 23, 23);		/* M6_CLOCK_EN */
436 	l = FLD_MOD(l, 0, 25, 25);		/* M7_CLOCK_EN */
437 	writel_relaxed(l, base + PLL_CONFIGURATION2);
438 
439 	writel_relaxed(1, base + PLL_GO);	/* PLL_GO */
440 
441 	if (wait_for_bit_change(base + PLL_GO, 0, 0) != 0) {
442 		DSSERR("DSS DPLL GO bit not going down.\n");
443 		r = -EIO;
444 		goto err;
445 	}
446 
447 	if (wait_for_bit_change(base + PLL_STATUS, 1, 1) != 1) {
448 		DSSERR("cannot lock DSS DPLL\n");
449 		r = -EIO;
450 		goto err;
451 	}
452 
453 	l = readl_relaxed(base + PLL_CONFIGURATION2);
454 	l = FLD_MOD(l, 1, 14, 14);			/* PHY_CLKINEN */
455 	l = FLD_MOD(l, cinfo->mX[0] ? 1 : 0, 16, 16);	/* M4_CLOCK_EN */
456 	l = FLD_MOD(l, cinfo->mX[1] ? 1 : 0, 18, 18);	/* M5_CLOCK_EN */
457 	l = FLD_MOD(l, 0, 20, 20);			/* HSDIVBYPASS */
458 	l = FLD_MOD(l, cinfo->mX[2] ? 1 : 0, 23, 23);	/* M6_CLOCK_EN */
459 	l = FLD_MOD(l, cinfo->mX[3] ? 1 : 0, 25, 25);	/* M7_CLOCK_EN */
460 	writel_relaxed(l, base + PLL_CONFIGURATION2);
461 
462 	r = dss_wait_hsdiv_ack(pll,
463 		(cinfo->mX[0] ? BIT(7) : 0) |
464 		(cinfo->mX[1] ? BIT(8) : 0) |
465 		(cinfo->mX[2] ? BIT(10) : 0) |
466 		(cinfo->mX[3] ? BIT(11) : 0));
467 	if (r) {
468 		DSSERR("failed to enable HSDIV clocks\n");
469 		goto err;
470 	}
471 
472 err:
473 	return r;
474 }
475 
476 int dss_pll_write_config_type_b(struct dss_pll *pll,
477 		const struct dss_pll_clock_info *cinfo)
478 {
479 	const struct dss_pll_hw *hw = pll->hw;
480 	void __iomem *base = pll->base;
481 	u32 l;
482 
483 	l = 0;
484 	l = FLD_MOD(l, cinfo->m, 20, 9);	/* PLL_REGM */
485 	l = FLD_MOD(l, cinfo->n - 1, 8, 1);	/* PLL_REGN */
486 	writel_relaxed(l, base + PLL_CONFIGURATION1);
487 
488 	l = readl_relaxed(base + PLL_CONFIGURATION2);
489 	l = FLD_MOD(l, 0x0, 12, 12);	/* PLL_HIGHFREQ divide by 2 */
490 	l = FLD_MOD(l, 0x1, 13, 13);	/* PLL_REFEN */
491 	l = FLD_MOD(l, 0x0, 14, 14);	/* PHY_CLKINEN */
492 	if (hw->has_refsel)
493 		l = FLD_MOD(l, 0x3, 22, 21);	/* REFSEL = SYSCLK */
494 
495 	/* PLL_SELFREQDCO */
496 	if (cinfo->clkdco > hw->clkdco_low)
497 		l = FLD_MOD(l, 0x4, 3, 1);
498 	else
499 		l = FLD_MOD(l, 0x2, 3, 1);
500 	writel_relaxed(l, base + PLL_CONFIGURATION2);
501 
502 	l = readl_relaxed(base + PLL_CONFIGURATION3);
503 	l = FLD_MOD(l, cinfo->sd, 17, 10);	/* PLL_REGSD */
504 	writel_relaxed(l, base + PLL_CONFIGURATION3);
505 
506 	l = readl_relaxed(base + PLL_CONFIGURATION4);
507 	l = FLD_MOD(l, cinfo->mX[0], 24, 18);	/* PLL_REGM2 */
508 	l = FLD_MOD(l, cinfo->mf, 17, 0);	/* PLL_REGM_F */
509 	writel_relaxed(l, base + PLL_CONFIGURATION4);
510 
511 	writel_relaxed(1, base + PLL_GO);	/* PLL_GO */
512 
513 	if (wait_for_bit_change(base + PLL_GO, 0, 0) != 0) {
514 		DSSERR("DSS DPLL GO bit not going down.\n");
515 		return -EIO;
516 	}
517 
518 	if (wait_for_bit_change(base + PLL_STATUS, 1, 1) != 1) {
519 		DSSERR("cannot lock DSS DPLL\n");
520 		return -ETIMEDOUT;
521 	}
522 
523 	return 0;
524 }
525