1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) 2014 MundoReader S.L.
4 * Author: Heiko Stuebner <heiko@sntech.de>
5 *
6 * Copyright (c) 2016 Rockchip Electronics Co. Ltd.
7 * Author: Xing Zheng <zhengxing@rock-chips.com>
8 *
9 * based on
10 *
11 * samsung/clk.c
12 * Copyright (c) 2013 Samsung Electronics Co., Ltd.
13 * Copyright (c) 2013 Linaro Ltd.
14 * Author: Thomas Abraham <thomas.ab@samsung.com>
15 */
16
17#include <linux/slab.h>
18#include <linux/clk.h>
19#include <linux/clk-provider.h>
20#include <linux/io.h>
21#include <linux/mfd/syscon.h>
22#include <linux/regmap.h>
23#include <linux/reboot.h>
24
25#include "../clk-fractional-divider.h"
26#include "clk.h"
27
28/*
29 * Register a clock branch.
30 * Most clock branches have a form like
31 *
32 * src1 --|--\
33 *        |M |--[GATE]-[DIV]-
34 * src2 --|--/
35 *
36 * sometimes without one of those components.
37 */
38static struct clk *rockchip_clk_register_branch(const char *name,
39		const char *const *parent_names, u8 num_parents,
40		void __iomem *base,
41		int muxdiv_offset, u8 mux_shift, u8 mux_width, u8 mux_flags,
42		u32 *mux_table,
43		int div_offset, u8 div_shift, u8 div_width, u8 div_flags,
44		struct clk_div_table *div_table, int gate_offset,
45		u8 gate_shift, u8 gate_flags, unsigned long flags,
46		spinlock_t *lock)
47{
48	struct clk_hw *hw;
49	struct clk_mux *mux = NULL;
50	struct clk_gate *gate = NULL;
51	struct clk_divider *div = NULL;
52	const struct clk_ops *mux_ops = NULL, *div_ops = NULL,
53			     *gate_ops = NULL;
54	int ret;
55
56	if (num_parents > 1) {
57		mux = kzalloc(sizeof(*mux), GFP_KERNEL);
58		if (!mux)
59			return ERR_PTR(-ENOMEM);
60
61		mux->reg = base + muxdiv_offset;
62		mux->shift = mux_shift;
63		mux->mask = BIT(mux_width) - 1;
64		mux->flags = mux_flags;
65		mux->table = mux_table;
66		mux->lock = lock;
67		mux_ops = (mux_flags & CLK_MUX_READ_ONLY) ? &clk_mux_ro_ops
68							: &clk_mux_ops;
69	}
70
71	if (gate_offset >= 0) {
72		gate = kzalloc(sizeof(*gate), GFP_KERNEL);
73		if (!gate) {
74			ret = -ENOMEM;
75			goto err_gate;
76		}
77
78		gate->flags = gate_flags;
79		gate->reg = base + gate_offset;
80		gate->bit_idx = gate_shift;
81		gate->lock = lock;
82		gate_ops = &clk_gate_ops;
83	}
84
85	if (div_width > 0) {
86		div = kzalloc(sizeof(*div), GFP_KERNEL);
87		if (!div) {
88			ret = -ENOMEM;
89			goto err_div;
90		}
91
92		div->flags = div_flags;
93		if (div_offset)
94			div->reg = base + div_offset;
95		else
96			div->reg = base + muxdiv_offset;
97		div->shift = div_shift;
98		div->width = div_width;
99		div->lock = lock;
100		div->table = div_table;
101		div_ops = (div_flags & CLK_DIVIDER_READ_ONLY)
102						? &clk_divider_ro_ops
103						: &clk_divider_ops;
104	}
105
106	hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
107				       mux ? &mux->hw : NULL, mux_ops,
108				       div ? &div->hw : NULL, div_ops,
109				       gate ? &gate->hw : NULL, gate_ops,
110				       flags);
111	if (IS_ERR(hw)) {
112		kfree(div);
113		kfree(gate);
114		return ERR_CAST(hw);
115	}
116
117	return hw->clk;
118err_div:
119	kfree(gate);
120err_gate:
121	kfree(mux);
122	return ERR_PTR(ret);
123}
124
125struct rockchip_clk_frac {
126	struct notifier_block			clk_nb;
127	struct clk_fractional_divider		div;
128	struct clk_gate				gate;
129
130	struct clk_mux				mux;
131	const struct clk_ops			*mux_ops;
132	int					mux_frac_idx;
133
134	bool					rate_change_remuxed;
135	int					rate_change_idx;
136};
137
138#define to_rockchip_clk_frac_nb(nb) \
139			container_of(nb, struct rockchip_clk_frac, clk_nb)
140
141static int rockchip_clk_frac_notifier_cb(struct notifier_block *nb,
142					 unsigned long event, void *data)
143{
144	struct clk_notifier_data *ndata = data;
145	struct rockchip_clk_frac *frac = to_rockchip_clk_frac_nb(nb);
146	struct clk_mux *frac_mux = &frac->mux;
147	int ret = 0;
148
149	pr_debug("%s: event %lu, old_rate %lu, new_rate: %lu\n",
150		 __func__, event, ndata->old_rate, ndata->new_rate);
151	if (event == PRE_RATE_CHANGE) {
152		frac->rate_change_idx =
153				frac->mux_ops->get_parent(&frac_mux->hw);
154		if (frac->rate_change_idx != frac->mux_frac_idx) {
155			frac->mux_ops->set_parent(&frac_mux->hw,
156						  frac->mux_frac_idx);
157			frac->rate_change_remuxed = 1;
158		}
159	} else if (event == POST_RATE_CHANGE) {
160		/*
161		 * The POST_RATE_CHANGE notifier runs directly after the
162		 * divider clock is set in clk_change_rate, so we'll have
163		 * remuxed back to the original parent before clk_change_rate
164		 * reaches the mux itself.
165		 */
166		if (frac->rate_change_remuxed) {
167			frac->mux_ops->set_parent(&frac_mux->hw,
168						  frac->rate_change_idx);
169			frac->rate_change_remuxed = 0;
170		}
171	}
172
173	return notifier_from_errno(ret);
174}
175
176/*
177 * fractional divider must set that denominator is 20 times larger than
178 * numerator to generate precise clock frequency.
179 */
180static void rockchip_fractional_approximation(struct clk_hw *hw,
181		unsigned long rate, unsigned long *parent_rate,
182		unsigned long *m, unsigned long *n)
183{
184	struct clk_fractional_divider *fd = to_clk_fd(hw);
185	unsigned long p_rate, p_parent_rate;
186	struct clk_hw *p_parent;
187
188	p_rate = clk_hw_get_rate(clk_hw_get_parent(hw));
189	if ((rate * 20 > p_rate) && (p_rate % rate != 0)) {
190		p_parent = clk_hw_get_parent(clk_hw_get_parent(hw));
191		p_parent_rate = clk_hw_get_rate(p_parent);
192		*parent_rate = p_parent_rate;
193	}
194
195	fd->flags |= CLK_FRAC_DIVIDER_POWER_OF_TWO_PS;
196
197	clk_fractional_divider_general_approximation(hw, rate, parent_rate, m, n);
198}
199
200static void rockchip_clk_add_lookup(struct rockchip_clk_provider *ctx,
201				    struct clk *clk, unsigned int id)
202{
203	ctx->clk_data.clks[id] = clk;
204}
205
206static struct clk *rockchip_clk_register_frac_branch(
207		struct rockchip_clk_provider *ctx, const char *name,
208		const char *const *parent_names, u8 num_parents,
209		void __iomem *base, int muxdiv_offset, u8 div_flags,
210		int gate_offset, u8 gate_shift, u8 gate_flags,
211		unsigned long flags, struct rockchip_clk_branch *child,
212		spinlock_t *lock)
213{
214	struct clk_hw *hw;
215	struct rockchip_clk_frac *frac;
216	struct clk_gate *gate = NULL;
217	struct clk_fractional_divider *div = NULL;
218	const struct clk_ops *div_ops = NULL, *gate_ops = NULL;
219
220	if (muxdiv_offset < 0)
221		return ERR_PTR(-EINVAL);
222
223	if (child && child->branch_type != branch_mux) {
224		pr_err("%s: fractional child clock for %s can only be a mux\n",
225		       __func__, name);
226		return ERR_PTR(-EINVAL);
227	}
228
229	frac = kzalloc(sizeof(*frac), GFP_KERNEL);
230	if (!frac)
231		return ERR_PTR(-ENOMEM);
232
233	if (gate_offset >= 0) {
234		gate = &frac->gate;
235		gate->flags = gate_flags;
236		gate->reg = base + gate_offset;
237		gate->bit_idx = gate_shift;
238		gate->lock = lock;
239		gate_ops = &clk_gate_ops;
240	}
241
242	div = &frac->div;
243	div->flags = div_flags;
244	div->reg = base + muxdiv_offset;
245	div->mshift = 16;
246	div->mwidth = 16;
247	div->nshift = 0;
248	div->nwidth = 16;
249	div->lock = lock;
250	div->approximation = rockchip_fractional_approximation;
251	div_ops = &clk_fractional_divider_ops;
252
253	hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
254				       NULL, NULL,
255				       &div->hw, div_ops,
256				       gate ? &gate->hw : NULL, gate_ops,
257				       flags | CLK_SET_RATE_UNGATE);
258	if (IS_ERR(hw)) {
259		kfree(frac);
260		return ERR_CAST(hw);
261	}
262
263	if (child) {
264		struct clk_mux *frac_mux = &frac->mux;
265		struct clk_init_data init;
266		struct clk *mux_clk;
267		int ret;
268
269		frac->mux_frac_idx = match_string(child->parent_names,
270						  child->num_parents, name);
271		frac->mux_ops = &clk_mux_ops;
272		frac->clk_nb.notifier_call = rockchip_clk_frac_notifier_cb;
273
274		frac_mux->reg = base + child->muxdiv_offset;
275		frac_mux->shift = child->mux_shift;
276		frac_mux->mask = BIT(child->mux_width) - 1;
277		frac_mux->flags = child->mux_flags;
278		if (child->mux_table)
279			frac_mux->table = child->mux_table;
280		frac_mux->lock = lock;
281		frac_mux->hw.init = &init;
282
283		init.name = child->name;
284		init.flags = child->flags | CLK_SET_RATE_PARENT;
285		init.ops = frac->mux_ops;
286		init.parent_names = child->parent_names;
287		init.num_parents = child->num_parents;
288
289		mux_clk = clk_register(NULL, &frac_mux->hw);
290		if (IS_ERR(mux_clk)) {
291			kfree(frac);
292			return mux_clk;
293		}
294
295		rockchip_clk_add_lookup(ctx, mux_clk, child->id);
296
297		/* notifier on the fraction divider to catch rate changes */
298		if (frac->mux_frac_idx >= 0) {
299			pr_debug("%s: found fractional parent in mux at pos %d\n",
300				 __func__, frac->mux_frac_idx);
301			ret = clk_notifier_register(hw->clk, &frac->clk_nb);
302			if (ret)
303				pr_err("%s: failed to register clock notifier for %s\n",
304						__func__, name);
305		} else {
306			pr_warn("%s: could not find %s as parent of %s, rate changes may not work\n",
307				__func__, name, child->name);
308		}
309	}
310
311	return hw->clk;
312}
313
314static struct clk *rockchip_clk_register_factor_branch(const char *name,
315		const char *const *parent_names, u8 num_parents,
316		void __iomem *base, unsigned int mult, unsigned int div,
317		int gate_offset, u8 gate_shift, u8 gate_flags,
318		unsigned long flags, spinlock_t *lock)
319{
320	struct clk_hw *hw;
321	struct clk_gate *gate = NULL;
322	struct clk_fixed_factor *fix = NULL;
323
324	/* without gate, register a simple factor clock */
325	if (gate_offset == 0) {
326		return clk_register_fixed_factor(NULL, name,
327				parent_names[0], flags, mult,
328				div);
329	}
330
331	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
332	if (!gate)
333		return ERR_PTR(-ENOMEM);
334
335	gate->flags = gate_flags;
336	gate->reg = base + gate_offset;
337	gate->bit_idx = gate_shift;
338	gate->lock = lock;
339
340	fix = kzalloc(sizeof(*fix), GFP_KERNEL);
341	if (!fix) {
342		kfree(gate);
343		return ERR_PTR(-ENOMEM);
344	}
345
346	fix->mult = mult;
347	fix->div = div;
348
349	hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
350				       NULL, NULL,
351				       &fix->hw, &clk_fixed_factor_ops,
352				       &gate->hw, &clk_gate_ops, flags);
353	if (IS_ERR(hw)) {
354		kfree(fix);
355		kfree(gate);
356		return ERR_CAST(hw);
357	}
358
359	return hw->clk;
360}
361
362struct rockchip_clk_provider *rockchip_clk_init(struct device_node *np,
363						void __iomem *base,
364						unsigned long nr_clks)
365{
366	struct rockchip_clk_provider *ctx;
367	struct clk **clk_table;
368	int i;
369
370	ctx = kzalloc(sizeof(struct rockchip_clk_provider), GFP_KERNEL);
371	if (!ctx)
372		return ERR_PTR(-ENOMEM);
373
374	clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL);
375	if (!clk_table)
376		goto err_free;
377
378	for (i = 0; i < nr_clks; ++i)
379		clk_table[i] = ERR_PTR(-ENOENT);
380
381	ctx->reg_base = base;
382	ctx->clk_data.clks = clk_table;
383	ctx->clk_data.clk_num = nr_clks;
384	ctx->cru_node = np;
385	spin_lock_init(&ctx->lock);
386
387	ctx->grf = syscon_regmap_lookup_by_phandle(ctx->cru_node,
388						   "rockchip,grf");
389
390	return ctx;
391
392err_free:
393	kfree(ctx);
394	return ERR_PTR(-ENOMEM);
395}
396EXPORT_SYMBOL_GPL(rockchip_clk_init);
397
398void rockchip_clk_of_add_provider(struct device_node *np,
399				  struct rockchip_clk_provider *ctx)
400{
401	if (of_clk_add_provider(np, of_clk_src_onecell_get,
402				&ctx->clk_data))
403		pr_err("%s: could not register clk provider\n", __func__);
404}
405EXPORT_SYMBOL_GPL(rockchip_clk_of_add_provider);
406
407void rockchip_clk_register_plls(struct rockchip_clk_provider *ctx,
408				struct rockchip_pll_clock *list,
409				unsigned int nr_pll, int grf_lock_offset)
410{
411	struct clk *clk;
412	int idx;
413
414	for (idx = 0; idx < nr_pll; idx++, list++) {
415		clk = rockchip_clk_register_pll(ctx, list->type, list->name,
416				list->parent_names, list->num_parents,
417				list->con_offset, grf_lock_offset,
418				list->lock_shift, list->mode_offset,
419				list->mode_shift, list->rate_table,
420				list->flags, list->pll_flags);
421		if (IS_ERR(clk)) {
422			pr_err("%s: failed to register clock %s\n", __func__,
423				list->name);
424			continue;
425		}
426
427		rockchip_clk_add_lookup(ctx, clk, list->id);
428	}
429}
430EXPORT_SYMBOL_GPL(rockchip_clk_register_plls);
431
432unsigned long rockchip_clk_find_max_clk_id(struct rockchip_clk_branch *list,
433					   unsigned int nr_clk)
434{
435	unsigned long max = 0;
436	unsigned int idx;
437
438	for (idx = 0; idx < nr_clk; idx++, list++) {
439		if (list->id > max)
440			max = list->id;
441		if (list->child && list->child->id > max)
442			max = list->id;
443	}
444
445	return max;
446}
447EXPORT_SYMBOL_GPL(rockchip_clk_find_max_clk_id);
448
449void rockchip_clk_register_branches(struct rockchip_clk_provider *ctx,
450				    struct rockchip_clk_branch *list,
451				    unsigned int nr_clk)
452{
453	struct clk *clk = NULL;
454	unsigned int idx;
455	unsigned long flags;
456
457	for (idx = 0; idx < nr_clk; idx++, list++) {
458		flags = list->flags;
459
460		/* catch simple muxes */
461		switch (list->branch_type) {
462		case branch_mux:
463			if (list->mux_table)
464				clk = clk_register_mux_table(NULL, list->name,
465					list->parent_names, list->num_parents,
466					flags,
467					ctx->reg_base + list->muxdiv_offset,
468					list->mux_shift, list->mux_width,
469					list->mux_flags, list->mux_table,
470					&ctx->lock);
471			else
472				clk = clk_register_mux(NULL, list->name,
473					list->parent_names, list->num_parents,
474					flags,
475					ctx->reg_base + list->muxdiv_offset,
476					list->mux_shift, list->mux_width,
477					list->mux_flags, &ctx->lock);
478			break;
479		case branch_muxgrf:
480			clk = rockchip_clk_register_muxgrf(list->name,
481				list->parent_names, list->num_parents,
482				flags, ctx->grf, list->muxdiv_offset,
483				list->mux_shift, list->mux_width,
484				list->mux_flags);
485			break;
486		case branch_divider:
487			if (list->div_table)
488				clk = clk_register_divider_table(NULL,
489					list->name, list->parent_names[0],
490					flags,
491					ctx->reg_base + list->muxdiv_offset,
492					list->div_shift, list->div_width,
493					list->div_flags, list->div_table,
494					&ctx->lock);
495			else
496				clk = clk_register_divider(NULL, list->name,
497					list->parent_names[0], flags,
498					ctx->reg_base + list->muxdiv_offset,
499					list->div_shift, list->div_width,
500					list->div_flags, &ctx->lock);
501			break;
502		case branch_fraction_divider:
503			clk = rockchip_clk_register_frac_branch(ctx, list->name,
504				list->parent_names, list->num_parents,
505				ctx->reg_base, list->muxdiv_offset,
506				list->div_flags,
507				list->gate_offset, list->gate_shift,
508				list->gate_flags, flags, list->child,
509				&ctx->lock);
510			break;
511		case branch_half_divider:
512			clk = rockchip_clk_register_halfdiv(list->name,
513				list->parent_names, list->num_parents,
514				ctx->reg_base, list->muxdiv_offset,
515				list->mux_shift, list->mux_width,
516				list->mux_flags, list->div_shift,
517				list->div_width, list->div_flags,
518				list->gate_offset, list->gate_shift,
519				list->gate_flags, flags, &ctx->lock);
520			break;
521		case branch_gate:
522			flags |= CLK_SET_RATE_PARENT;
523
524			clk = clk_register_gate(NULL, list->name,
525				list->parent_names[0], flags,
526				ctx->reg_base + list->gate_offset,
527				list->gate_shift, list->gate_flags, &ctx->lock);
528			break;
529		case branch_composite:
530			clk = rockchip_clk_register_branch(list->name,
531				list->parent_names, list->num_parents,
532				ctx->reg_base, list->muxdiv_offset,
533				list->mux_shift,
534				list->mux_width, list->mux_flags,
535				list->mux_table, list->div_offset,
536				list->div_shift, list->div_width,
537				list->div_flags, list->div_table,
538				list->gate_offset, list->gate_shift,
539				list->gate_flags, flags, &ctx->lock);
540			break;
541		case branch_mmc:
542			clk = rockchip_clk_register_mmc(
543				list->name,
544				list->parent_names, list->num_parents,
545				ctx->reg_base + list->muxdiv_offset,
546				list->div_shift
547			);
548			break;
549		case branch_inverter:
550			clk = rockchip_clk_register_inverter(
551				list->name, list->parent_names,
552				list->num_parents,
553				ctx->reg_base + list->muxdiv_offset,
554				list->div_shift, list->div_flags, &ctx->lock);
555			break;
556		case branch_factor:
557			clk = rockchip_clk_register_factor_branch(
558				list->name, list->parent_names,
559				list->num_parents, ctx->reg_base,
560				list->div_shift, list->div_width,
561				list->gate_offset, list->gate_shift,
562				list->gate_flags, flags, &ctx->lock);
563			break;
564		case branch_ddrclk:
565			clk = rockchip_clk_register_ddrclk(
566				list->name, list->flags,
567				list->parent_names, list->num_parents,
568				list->muxdiv_offset, list->mux_shift,
569				list->mux_width, list->div_shift,
570				list->div_width, list->div_flags,
571				ctx->reg_base, &ctx->lock);
572			break;
573		}
574
575		/* none of the cases above matched */
576		if (!clk) {
577			pr_err("%s: unknown clock type %d\n",
578			       __func__, list->branch_type);
579			continue;
580		}
581
582		if (IS_ERR(clk)) {
583			pr_err("%s: failed to register clock %s: %ld\n",
584			       __func__, list->name, PTR_ERR(clk));
585			continue;
586		}
587
588		rockchip_clk_add_lookup(ctx, clk, list->id);
589	}
590}
591EXPORT_SYMBOL_GPL(rockchip_clk_register_branches);
592
593void rockchip_clk_register_armclk(struct rockchip_clk_provider *ctx,
594				  unsigned int lookup_id,
595				  const char *name, const char *const *parent_names,
596				  u8 num_parents,
597				  const struct rockchip_cpuclk_reg_data *reg_data,
598				  const struct rockchip_cpuclk_rate_table *rates,
599				  int nrates)
600{
601	struct clk *clk;
602
603	clk = rockchip_clk_register_cpuclk(name, parent_names, num_parents,
604					   reg_data, rates, nrates,
605					   ctx->reg_base, &ctx->lock);
606	if (IS_ERR(clk)) {
607		pr_err("%s: failed to register clock %s: %ld\n",
608		       __func__, name, PTR_ERR(clk));
609		return;
610	}
611
612	rockchip_clk_add_lookup(ctx, clk, lookup_id);
613}
614EXPORT_SYMBOL_GPL(rockchip_clk_register_armclk);
615
616void rockchip_clk_protect_critical(const char *const clocks[],
617				   int nclocks)
618{
619	int i;
620
621	/* Protect the clocks that needs to stay on */
622	for (i = 0; i < nclocks; i++) {
623		struct clk *clk = __clk_lookup(clocks[i]);
624
625		clk_prepare_enable(clk);
626	}
627}
628EXPORT_SYMBOL_GPL(rockchip_clk_protect_critical);
629
630static void __iomem *rst_base;
631static unsigned int reg_restart;
632static void (*cb_restart)(void);
633static int rockchip_restart_notify(struct notifier_block *this,
634				   unsigned long mode, void *cmd)
635{
636	if (cb_restart)
637		cb_restart();
638
639	writel(0xfdb9, rst_base + reg_restart);
640	return NOTIFY_DONE;
641}
642
643static struct notifier_block rockchip_restart_handler = {
644	.notifier_call = rockchip_restart_notify,
645	.priority = 128,
646};
647
648void
649rockchip_register_restart_notifier(struct rockchip_clk_provider *ctx,
650				   unsigned int reg,
651				   void (*cb)(void))
652{
653	int ret;
654
655	rst_base = ctx->reg_base;
656	reg_restart = reg;
657	cb_restart = cb;
658	ret = register_restart_handler(&rockchip_restart_handler);
659	if (ret)
660		pr_err("%s: cannot register restart handler, %d\n",
661		       __func__, ret);
662}
663EXPORT_SYMBOL_GPL(rockchip_register_restart_notifier);
664