xref: /openbmc/linux/drivers/clk/ti/fapll.c (revision e40573a4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <linux/clk.h>
4 #include <linux/clk-provider.h>
5 #include <linux/delay.h>
6 #include <linux/err.h>
7 #include <linux/io.h>
8 #include <linux/math64.h>
9 #include <linux/of.h>
10 #include <linux/of_address.h>
11 #include <linux/clk/ti.h>
12 
13 #include "clock.h"
14 
15 /* FAPLL Control Register PLL_CTRL */
16 #define FAPLL_MAIN_MULT_N_SHIFT	16
17 #define FAPLL_MAIN_DIV_P_SHIFT	8
18 #define FAPLL_MAIN_LOCK		BIT(7)
19 #define FAPLL_MAIN_PLLEN	BIT(3)
20 #define FAPLL_MAIN_BP		BIT(2)
21 #define FAPLL_MAIN_LOC_CTL	BIT(0)
22 
23 #define FAPLL_MAIN_MAX_MULT_N	0xffff
24 #define FAPLL_MAIN_MAX_DIV_P	0xff
25 #define FAPLL_MAIN_CLEAR_MASK	\
26 	((FAPLL_MAIN_MAX_MULT_N << FAPLL_MAIN_MULT_N_SHIFT) | \
27 	 (FAPLL_MAIN_DIV_P_SHIFT << FAPLL_MAIN_DIV_P_SHIFT) | \
28 	 FAPLL_MAIN_LOC_CTL)
29 
30 /* FAPLL powerdown register PWD */
31 #define FAPLL_PWD_OFFSET	4
32 
33 #define MAX_FAPLL_OUTPUTS	7
34 #define FAPLL_MAX_RETRIES	1000
35 
36 #define to_fapll(_hw)		container_of(_hw, struct fapll_data, hw)
37 #define to_synth(_hw)		container_of(_hw, struct fapll_synth, hw)
38 
39 /* The bypass bit is inverted on the ddr_pll.. */
40 #define fapll_is_ddr_pll(va)	(((u32)(va) & 0xffff) == 0x0440)
41 
42 /*
43  * The audio_pll_clk1 input is hard wired to the 27MHz bypass clock,
44  * and the audio_pll_clk1 synthesizer is hardwared to 32KiHz output.
45  */
46 #define is_ddr_pll_clk1(va)	(((u32)(va) & 0xffff) == 0x044c)
47 #define is_audio_pll_clk1(va)	(((u32)(va) & 0xffff) == 0x04a8)
48 
49 /* Synthesizer divider register */
50 #define SYNTH_LDMDIV1		BIT(8)
51 
52 /* Synthesizer frequency register */
53 #define SYNTH_LDFREQ		BIT(31)
54 
55 #define SYNTH_PHASE_K		8
56 #define SYNTH_MAX_INT_DIV	0xf
57 #define SYNTH_MAX_DIV_M		0xff
58 
59 struct fapll_data {
60 	struct clk_hw hw;
61 	void __iomem *base;
62 	const char *name;
63 	struct clk *clk_ref;
64 	struct clk *clk_bypass;
65 	struct clk_onecell_data outputs;
66 	bool bypass_bit_inverted;
67 };
68 
69 struct fapll_synth {
70 	struct clk_hw hw;
71 	struct fapll_data *fd;
72 	int index;
73 	void __iomem *freq;
74 	void __iomem *div;
75 	const char *name;
76 	struct clk *clk_pll;
77 };
78 
79 static bool ti_fapll_clock_is_bypass(struct fapll_data *fd)
80 {
81 	u32 v = readl_relaxed(fd->base);
82 
83 	if (fd->bypass_bit_inverted)
84 		return !(v & FAPLL_MAIN_BP);
85 	else
86 		return !!(v & FAPLL_MAIN_BP);
87 }
88 
89 static void ti_fapll_set_bypass(struct fapll_data *fd)
90 {
91 	u32 v = readl_relaxed(fd->base);
92 
93 	if (fd->bypass_bit_inverted)
94 		v &= ~FAPLL_MAIN_BP;
95 	else
96 		v |= FAPLL_MAIN_BP;
97 	writel_relaxed(v, fd->base);
98 }
99 
100 static void ti_fapll_clear_bypass(struct fapll_data *fd)
101 {
102 	u32 v = readl_relaxed(fd->base);
103 
104 	if (fd->bypass_bit_inverted)
105 		v |= FAPLL_MAIN_BP;
106 	else
107 		v &= ~FAPLL_MAIN_BP;
108 	writel_relaxed(v, fd->base);
109 }
110 
111 static int ti_fapll_wait_lock(struct fapll_data *fd)
112 {
113 	int retries = FAPLL_MAX_RETRIES;
114 	u32 v;
115 
116 	while ((v = readl_relaxed(fd->base))) {
117 		if (v & FAPLL_MAIN_LOCK)
118 			return 0;
119 
120 		if (retries-- <= 0)
121 			break;
122 
123 		udelay(1);
124 	}
125 
126 	pr_err("%s failed to lock\n", fd->name);
127 
128 	return -ETIMEDOUT;
129 }
130 
131 static int ti_fapll_enable(struct clk_hw *hw)
132 {
133 	struct fapll_data *fd = to_fapll(hw);
134 	u32 v = readl_relaxed(fd->base);
135 
136 	v |= FAPLL_MAIN_PLLEN;
137 	writel_relaxed(v, fd->base);
138 	ti_fapll_wait_lock(fd);
139 
140 	return 0;
141 }
142 
143 static void ti_fapll_disable(struct clk_hw *hw)
144 {
145 	struct fapll_data *fd = to_fapll(hw);
146 	u32 v = readl_relaxed(fd->base);
147 
148 	v &= ~FAPLL_MAIN_PLLEN;
149 	writel_relaxed(v, fd->base);
150 }
151 
152 static int ti_fapll_is_enabled(struct clk_hw *hw)
153 {
154 	struct fapll_data *fd = to_fapll(hw);
155 	u32 v = readl_relaxed(fd->base);
156 
157 	return v & FAPLL_MAIN_PLLEN;
158 }
159 
160 static unsigned long ti_fapll_recalc_rate(struct clk_hw *hw,
161 					  unsigned long parent_rate)
162 {
163 	struct fapll_data *fd = to_fapll(hw);
164 	u32 fapll_n, fapll_p, v;
165 	u64 rate;
166 
167 	if (ti_fapll_clock_is_bypass(fd))
168 		return parent_rate;
169 
170 	rate = parent_rate;
171 
172 	/* PLL pre-divider is P and multiplier is N */
173 	v = readl_relaxed(fd->base);
174 	fapll_p = (v >> 8) & 0xff;
175 	if (fapll_p)
176 		do_div(rate, fapll_p);
177 	fapll_n = v >> 16;
178 	if (fapll_n)
179 		rate *= fapll_n;
180 
181 	return rate;
182 }
183 
184 static u8 ti_fapll_get_parent(struct clk_hw *hw)
185 {
186 	struct fapll_data *fd = to_fapll(hw);
187 
188 	if (ti_fapll_clock_is_bypass(fd))
189 		return 1;
190 
191 	return 0;
192 }
193 
194 static int ti_fapll_set_div_mult(unsigned long rate,
195 				 unsigned long parent_rate,
196 				 u32 *pre_div_p, u32 *mult_n)
197 {
198 	/*
199 	 * So far no luck getting decent clock with PLL divider,
200 	 * PLL does not seem to lock and the signal does not look
201 	 * right. It seems the divider can only be used together
202 	 * with the multiplier?
203 	 */
204 	if (rate < parent_rate) {
205 		pr_warn("FAPLL main divider rates unsupported\n");
206 		return -EINVAL;
207 	}
208 
209 	*mult_n = rate / parent_rate;
210 	if (*mult_n > FAPLL_MAIN_MAX_MULT_N)
211 		return -EINVAL;
212 	*pre_div_p = 1;
213 
214 	return 0;
215 }
216 
217 static long ti_fapll_round_rate(struct clk_hw *hw, unsigned long rate,
218 				unsigned long *parent_rate)
219 {
220 	u32 pre_div_p, mult_n;
221 	int error;
222 
223 	if (!rate)
224 		return -EINVAL;
225 
226 	error = ti_fapll_set_div_mult(rate, *parent_rate,
227 				      &pre_div_p, &mult_n);
228 	if (error)
229 		return error;
230 
231 	rate = *parent_rate / pre_div_p;
232 	rate *= mult_n;
233 
234 	return rate;
235 }
236 
237 static int ti_fapll_set_rate(struct clk_hw *hw, unsigned long rate,
238 			     unsigned long parent_rate)
239 {
240 	struct fapll_data *fd = to_fapll(hw);
241 	u32 pre_div_p, mult_n, v;
242 	int error;
243 
244 	if (!rate)
245 		return -EINVAL;
246 
247 	error = ti_fapll_set_div_mult(rate, parent_rate,
248 				      &pre_div_p, &mult_n);
249 	if (error)
250 		return error;
251 
252 	ti_fapll_set_bypass(fd);
253 	v = readl_relaxed(fd->base);
254 	v &= ~FAPLL_MAIN_CLEAR_MASK;
255 	v |= pre_div_p << FAPLL_MAIN_DIV_P_SHIFT;
256 	v |= mult_n << FAPLL_MAIN_MULT_N_SHIFT;
257 	writel_relaxed(v, fd->base);
258 	if (ti_fapll_is_enabled(hw))
259 		ti_fapll_wait_lock(fd);
260 	ti_fapll_clear_bypass(fd);
261 
262 	return 0;
263 }
264 
265 static const struct clk_ops ti_fapll_ops = {
266 	.enable = ti_fapll_enable,
267 	.disable = ti_fapll_disable,
268 	.is_enabled = ti_fapll_is_enabled,
269 	.recalc_rate = ti_fapll_recalc_rate,
270 	.get_parent = ti_fapll_get_parent,
271 	.round_rate = ti_fapll_round_rate,
272 	.set_rate = ti_fapll_set_rate,
273 };
274 
275 static int ti_fapll_synth_enable(struct clk_hw *hw)
276 {
277 	struct fapll_synth *synth = to_synth(hw);
278 	u32 v = readl_relaxed(synth->fd->base + FAPLL_PWD_OFFSET);
279 
280 	v &= ~(1 << synth->index);
281 	writel_relaxed(v, synth->fd->base + FAPLL_PWD_OFFSET);
282 
283 	return 0;
284 }
285 
286 static void ti_fapll_synth_disable(struct clk_hw *hw)
287 {
288 	struct fapll_synth *synth = to_synth(hw);
289 	u32 v = readl_relaxed(synth->fd->base + FAPLL_PWD_OFFSET);
290 
291 	v |= 1 << synth->index;
292 	writel_relaxed(v, synth->fd->base + FAPLL_PWD_OFFSET);
293 }
294 
295 static int ti_fapll_synth_is_enabled(struct clk_hw *hw)
296 {
297 	struct fapll_synth *synth = to_synth(hw);
298 	u32 v = readl_relaxed(synth->fd->base + FAPLL_PWD_OFFSET);
299 
300 	return !(v & (1 << synth->index));
301 }
302 
303 /*
304  * See dm816x TRM chapter 1.10.3 Flying Adder PLL fore more info
305  */
306 static unsigned long ti_fapll_synth_recalc_rate(struct clk_hw *hw,
307 						unsigned long parent_rate)
308 {
309 	struct fapll_synth *synth = to_synth(hw);
310 	u32 synth_div_m;
311 	u64 rate;
312 
313 	/* The audio_pll_clk1 is hardwired to produce 32.768KiHz clock */
314 	if (!synth->div)
315 		return 32768;
316 
317 	/*
318 	 * PLL in bypass sets the synths in bypass mode too. The PLL rate
319 	 * can be also be set to 27MHz, so we can't use parent_rate to
320 	 * check for bypass mode.
321 	 */
322 	if (ti_fapll_clock_is_bypass(synth->fd))
323 		return parent_rate;
324 
325 	rate = parent_rate;
326 
327 	/*
328 	 * Synth frequency integer and fractional divider.
329 	 * Note that the phase output K is 8, so the result needs
330 	 * to be multiplied by SYNTH_PHASE_K.
331 	 */
332 	if (synth->freq) {
333 		u32 v, synth_int_div, synth_frac_div, synth_div_freq;
334 
335 		v = readl_relaxed(synth->freq);
336 		synth_int_div = (v >> 24) & 0xf;
337 		synth_frac_div = v & 0xffffff;
338 		synth_div_freq = (synth_int_div * 10000000) + synth_frac_div;
339 		rate *= 10000000;
340 		do_div(rate, synth_div_freq);
341 		rate *= SYNTH_PHASE_K;
342 	}
343 
344 	/* Synth post-divider M */
345 	synth_div_m = readl_relaxed(synth->div) & SYNTH_MAX_DIV_M;
346 
347 	return DIV_ROUND_UP_ULL(rate, synth_div_m);
348 }
349 
350 static unsigned long ti_fapll_synth_get_frac_rate(struct clk_hw *hw,
351 						  unsigned long parent_rate)
352 {
353 	struct fapll_synth *synth = to_synth(hw);
354 	unsigned long current_rate, frac_rate;
355 	u32 post_div_m;
356 
357 	current_rate = ti_fapll_synth_recalc_rate(hw, parent_rate);
358 	post_div_m = readl_relaxed(synth->div) & SYNTH_MAX_DIV_M;
359 	frac_rate = current_rate * post_div_m;
360 
361 	return frac_rate;
362 }
363 
364 static u32 ti_fapll_synth_set_frac_rate(struct fapll_synth *synth,
365 					unsigned long rate,
366 					unsigned long parent_rate)
367 {
368 	u32 post_div_m, synth_int_div = 0, synth_frac_div = 0, v;
369 
370 	post_div_m = DIV_ROUND_UP_ULL((u64)parent_rate * SYNTH_PHASE_K, rate);
371 	post_div_m = post_div_m / SYNTH_MAX_INT_DIV;
372 	if (post_div_m > SYNTH_MAX_DIV_M)
373 		return -EINVAL;
374 	if (!post_div_m)
375 		post_div_m = 1;
376 
377 	for (; post_div_m < SYNTH_MAX_DIV_M; post_div_m++) {
378 		synth_int_div = DIV_ROUND_UP_ULL((u64)parent_rate *
379 						 SYNTH_PHASE_K *
380 						 10000000,
381 						 rate * post_div_m);
382 		synth_frac_div = synth_int_div % 10000000;
383 		synth_int_div /= 10000000;
384 
385 		if (synth_int_div <= SYNTH_MAX_INT_DIV)
386 			break;
387 	}
388 
389 	if (synth_int_div > SYNTH_MAX_INT_DIV)
390 		return -EINVAL;
391 
392 	v = readl_relaxed(synth->freq);
393 	v &= ~0x1fffffff;
394 	v |= (synth_int_div & SYNTH_MAX_INT_DIV) << 24;
395 	v |= (synth_frac_div & 0xffffff);
396 	v |= SYNTH_LDFREQ;
397 	writel_relaxed(v, synth->freq);
398 
399 	return post_div_m;
400 }
401 
402 static long ti_fapll_synth_round_rate(struct clk_hw *hw, unsigned long rate,
403 				      unsigned long *parent_rate)
404 {
405 	struct fapll_synth *synth = to_synth(hw);
406 	struct fapll_data *fd = synth->fd;
407 	unsigned long r;
408 
409 	if (ti_fapll_clock_is_bypass(fd) || !synth->div || !rate)
410 		return -EINVAL;
411 
412 	/* Only post divider m available with no fractional divider? */
413 	if (!synth->freq) {
414 		unsigned long frac_rate;
415 		u32 synth_post_div_m;
416 
417 		frac_rate = ti_fapll_synth_get_frac_rate(hw, *parent_rate);
418 		synth_post_div_m = DIV_ROUND_UP(frac_rate, rate);
419 		r = DIV_ROUND_UP(frac_rate, synth_post_div_m);
420 		goto out;
421 	}
422 
423 	r = *parent_rate * SYNTH_PHASE_K;
424 	if (rate > r)
425 		goto out;
426 
427 	r = DIV_ROUND_UP_ULL(r, SYNTH_MAX_INT_DIV * SYNTH_MAX_DIV_M);
428 	if (rate < r)
429 		goto out;
430 
431 	r = rate;
432 out:
433 	return r;
434 }
435 
436 static int ti_fapll_synth_set_rate(struct clk_hw *hw, unsigned long rate,
437 				   unsigned long parent_rate)
438 {
439 	struct fapll_synth *synth = to_synth(hw);
440 	struct fapll_data *fd = synth->fd;
441 	unsigned long frac_rate, post_rate = 0;
442 	u32 post_div_m = 0, v;
443 
444 	if (ti_fapll_clock_is_bypass(fd) || !synth->div || !rate)
445 		return -EINVAL;
446 
447 	/* Produce the rate with just post divider M? */
448 	frac_rate = ti_fapll_synth_get_frac_rate(hw, parent_rate);
449 	if (frac_rate < rate) {
450 		if (!synth->freq)
451 			return -EINVAL;
452 	} else {
453 		post_div_m = DIV_ROUND_UP(frac_rate, rate);
454 		if (post_div_m && (post_div_m <= SYNTH_MAX_DIV_M))
455 			post_rate = DIV_ROUND_UP(frac_rate, post_div_m);
456 		if (!synth->freq && !post_rate)
457 			return -EINVAL;
458 	}
459 
460 	/* Need to recalculate the fractional divider? */
461 	if ((post_rate != rate) && synth->freq)
462 		post_div_m = ti_fapll_synth_set_frac_rate(synth,
463 							  rate,
464 							  parent_rate);
465 
466 	v = readl_relaxed(synth->div);
467 	v &= ~SYNTH_MAX_DIV_M;
468 	v |= post_div_m;
469 	v |= SYNTH_LDMDIV1;
470 	writel_relaxed(v, synth->div);
471 
472 	return 0;
473 }
474 
475 static const struct clk_ops ti_fapll_synt_ops = {
476 	.enable = ti_fapll_synth_enable,
477 	.disable = ti_fapll_synth_disable,
478 	.is_enabled = ti_fapll_synth_is_enabled,
479 	.recalc_rate = ti_fapll_synth_recalc_rate,
480 	.round_rate = ti_fapll_synth_round_rate,
481 	.set_rate = ti_fapll_synth_set_rate,
482 };
483 
484 static struct clk * __init ti_fapll_synth_setup(struct fapll_data *fd,
485 						void __iomem *freq,
486 						void __iomem *div,
487 						int index,
488 						const char *name,
489 						const char *parent,
490 						struct clk *pll_clk)
491 {
492 	struct clk_init_data *init;
493 	struct fapll_synth *synth;
494 	struct clk *clk = ERR_PTR(-ENOMEM);
495 
496 	init = kzalloc(sizeof(*init), GFP_KERNEL);
497 	if (!init)
498 		return ERR_PTR(-ENOMEM);
499 
500 	init->ops = &ti_fapll_synt_ops;
501 	init->name = name;
502 	init->parent_names = &parent;
503 	init->num_parents = 1;
504 
505 	synth = kzalloc(sizeof(*synth), GFP_KERNEL);
506 	if (!synth)
507 		goto free;
508 
509 	synth->fd = fd;
510 	synth->index = index;
511 	synth->freq = freq;
512 	synth->div = div;
513 	synth->name = name;
514 	synth->hw.init = init;
515 	synth->clk_pll = pll_clk;
516 
517 	clk = clk_register(NULL, &synth->hw);
518 	if (IS_ERR(clk)) {
519 		pr_err("failed to register clock\n");
520 		goto free;
521 	}
522 
523 	return clk;
524 
525 free:
526 	kfree(synth);
527 	kfree(init);
528 
529 	return clk;
530 }
531 
532 static void __init ti_fapll_setup(struct device_node *node)
533 {
534 	struct fapll_data *fd;
535 	struct clk_init_data *init = NULL;
536 	const char *parent_name[2];
537 	struct clk *pll_clk;
538 	const char *name;
539 	int i;
540 
541 	fd = kzalloc(sizeof(*fd), GFP_KERNEL);
542 	if (!fd)
543 		return;
544 
545 	fd->outputs.clks = kzalloc(sizeof(struct clk *) *
546 				   MAX_FAPLL_OUTPUTS + 1,
547 				   GFP_KERNEL);
548 	if (!fd->outputs.clks)
549 		goto free;
550 
551 	init = kzalloc(sizeof(*init), GFP_KERNEL);
552 	if (!init)
553 		goto free;
554 
555 	init->ops = &ti_fapll_ops;
556 	name = ti_dt_clk_name(node);
557 	init->name = name;
558 
559 	init->num_parents = of_clk_get_parent_count(node);
560 	if (init->num_parents != 2) {
561 		pr_err("%pOFn must have two parents\n", node);
562 		goto free;
563 	}
564 
565 	of_clk_parent_fill(node, parent_name, 2);
566 	init->parent_names = parent_name;
567 
568 	fd->clk_ref = of_clk_get(node, 0);
569 	if (IS_ERR(fd->clk_ref)) {
570 		pr_err("%pOFn could not get clk_ref\n", node);
571 		goto free;
572 	}
573 
574 	fd->clk_bypass = of_clk_get(node, 1);
575 	if (IS_ERR(fd->clk_bypass)) {
576 		pr_err("%pOFn could not get clk_bypass\n", node);
577 		goto free;
578 	}
579 
580 	fd->base = of_iomap(node, 0);
581 	if (!fd->base) {
582 		pr_err("%pOFn could not get IO base\n", node);
583 		goto free;
584 	}
585 
586 	if (fapll_is_ddr_pll(fd->base))
587 		fd->bypass_bit_inverted = true;
588 
589 	fd->name = name;
590 	fd->hw.init = init;
591 
592 	/* Register the parent PLL */
593 	pll_clk = clk_register(NULL, &fd->hw);
594 	if (IS_ERR(pll_clk))
595 		goto unmap;
596 
597 	fd->outputs.clks[0] = pll_clk;
598 	fd->outputs.clk_num++;
599 
600 	/*
601 	 * Set up the child synthesizers starting at index 1 as the
602 	 * PLL output is at index 0. We need to check the clock-indices
603 	 * for numbering in case there are holes in the synth mapping,
604 	 * and then probe the synth register to see if it has a FREQ
605 	 * register available.
606 	 */
607 	for (i = 0; i < MAX_FAPLL_OUTPUTS; i++) {
608 		const char *output_name;
609 		void __iomem *freq, *div;
610 		struct clk *synth_clk;
611 		int output_instance;
612 		u32 v;
613 
614 		if (of_property_read_string_index(node, "clock-output-names",
615 						  i, &output_name))
616 			continue;
617 
618 		if (of_property_read_u32_index(node, "clock-indices", i,
619 					       &output_instance))
620 			output_instance = i;
621 
622 		freq = fd->base + (output_instance * 8);
623 		div = freq + 4;
624 
625 		/* Check for hardwired audio_pll_clk1 */
626 		if (is_audio_pll_clk1(freq)) {
627 			freq = NULL;
628 			div = NULL;
629 		} else {
630 			/* Does the synthesizer have a FREQ register? */
631 			v = readl_relaxed(freq);
632 			if (!v)
633 				freq = NULL;
634 		}
635 		synth_clk = ti_fapll_synth_setup(fd, freq, div, output_instance,
636 						 output_name, name, pll_clk);
637 		if (IS_ERR(synth_clk))
638 			continue;
639 
640 		fd->outputs.clks[output_instance] = synth_clk;
641 		fd->outputs.clk_num++;
642 
643 		clk_register_clkdev(synth_clk, output_name, NULL);
644 	}
645 
646 	/* Register the child synthesizers as the FAPLL outputs */
647 	of_clk_add_provider(node, of_clk_src_onecell_get, &fd->outputs);
648 	/* Add clock alias for the outputs */
649 
650 	kfree(init);
651 
652 	return;
653 
654 unmap:
655 	iounmap(fd->base);
656 free:
657 	if (fd->clk_bypass)
658 		clk_put(fd->clk_bypass);
659 	if (fd->clk_ref)
660 		clk_put(fd->clk_ref);
661 	kfree(fd->outputs.clks);
662 	kfree(fd);
663 	kfree(init);
664 }
665 
666 CLK_OF_DECLARE(ti_fapll_clock, "ti,dm816-fapll-clock", ti_fapll_setup);
667