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