xref: /linux/drivers/clk/rockchip/clk.c (revision 03f7c1d2a49acd30e38789cd809d3300721e9b0e)
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 #include <linux/rational.h>
25 
26 #include "../clk-fractional-divider.h"
27 #include "clk.h"
28 
29 /*
30  * Register a clock branch.
31  * Most clock branches have a form like
32  *
33  * src1 --|--\
34  *        |M |--[GATE]-[DIV]-
35  * src2 --|--/
36  *
37  * sometimes without one of those components.
38  */
39 static struct clk *rockchip_clk_register_branch(const char *name,
40 		const char *const *parent_names, u8 num_parents,
41 		void __iomem *base,
42 		int muxdiv_offset, u8 mux_shift, u8 mux_width, u8 mux_flags,
43 		u32 *mux_table,
44 		int div_offset, u8 div_shift, u8 div_width, u8 div_flags,
45 		struct clk_div_table *div_table, int gate_offset,
46 		u8 gate_shift, u8 gate_flags, unsigned long flags,
47 		spinlock_t *lock)
48 {
49 	struct clk_hw *hw;
50 	struct clk_mux *mux = NULL;
51 	struct clk_gate *gate = NULL;
52 	struct clk_divider *div = NULL;
53 	const struct clk_ops *mux_ops = NULL, *div_ops = NULL,
54 			     *gate_ops = NULL;
55 	int ret;
56 
57 	if (num_parents > 1) {
58 		mux = kzalloc(sizeof(*mux), GFP_KERNEL);
59 		if (!mux)
60 			return ERR_PTR(-ENOMEM);
61 
62 		mux->reg = base + muxdiv_offset;
63 		mux->shift = mux_shift;
64 		mux->mask = BIT(mux_width) - 1;
65 		mux->flags = mux_flags;
66 		mux->table = mux_table;
67 		mux->lock = lock;
68 		mux_ops = (mux_flags & CLK_MUX_READ_ONLY) ? &clk_mux_ro_ops
69 							: &clk_mux_ops;
70 	}
71 
72 	if (gate_offset >= 0) {
73 		gate = kzalloc(sizeof(*gate), GFP_KERNEL);
74 		if (!gate) {
75 			ret = -ENOMEM;
76 			goto err_gate;
77 		}
78 
79 		gate->flags = gate_flags;
80 		gate->reg = base + gate_offset;
81 		gate->bit_idx = gate_shift;
82 		gate->lock = lock;
83 		gate_ops = &clk_gate_ops;
84 	}
85 
86 	if (div_width > 0) {
87 		div = kzalloc(sizeof(*div), GFP_KERNEL);
88 		if (!div) {
89 			ret = -ENOMEM;
90 			goto err_div;
91 		}
92 
93 		div->flags = div_flags;
94 		if (div_offset)
95 			div->reg = base + div_offset;
96 		else
97 			div->reg = base + muxdiv_offset;
98 		div->shift = div_shift;
99 		div->width = div_width;
100 		div->lock = lock;
101 		div->table = div_table;
102 		div_ops = (div_flags & CLK_DIVIDER_READ_ONLY)
103 						? &clk_divider_ro_ops
104 						: &clk_divider_ops;
105 	}
106 
107 	hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
108 				       mux ? &mux->hw : NULL, mux_ops,
109 				       div ? &div->hw : NULL, div_ops,
110 				       gate ? &gate->hw : NULL, gate_ops,
111 				       flags);
112 	if (IS_ERR(hw)) {
113 		kfree(div);
114 		kfree(gate);
115 		return ERR_CAST(hw);
116 	}
117 
118 	return hw->clk;
119 err_div:
120 	kfree(gate);
121 err_gate:
122 	kfree(mux);
123 	return ERR_PTR(ret);
124 }
125 
126 struct rockchip_clk_frac {
127 	struct notifier_block			clk_nb;
128 	struct clk_fractional_divider		div;
129 	struct clk_gate				gate;
130 
131 	struct clk_mux				mux;
132 	const struct clk_ops			*mux_ops;
133 	int					mux_frac_idx;
134 
135 	bool					rate_change_remuxed;
136 	int					rate_change_idx;
137 };
138 
139 #define to_rockchip_clk_frac_nb(nb) \
140 			container_of(nb, struct rockchip_clk_frac, clk_nb)
141 
142 static int rockchip_clk_frac_notifier_cb(struct notifier_block *nb,
143 					 unsigned long event, void *data)
144 {
145 	struct clk_notifier_data *ndata = data;
146 	struct rockchip_clk_frac *frac = to_rockchip_clk_frac_nb(nb);
147 	struct clk_mux *frac_mux = &frac->mux;
148 	int ret = 0;
149 
150 	pr_debug("%s: event %lu, old_rate %lu, new_rate: %lu\n",
151 		 __func__, event, ndata->old_rate, ndata->new_rate);
152 	if (event == PRE_RATE_CHANGE) {
153 		frac->rate_change_idx =
154 				frac->mux_ops->get_parent(&frac_mux->hw);
155 		if (frac->rate_change_idx != frac->mux_frac_idx) {
156 			frac->mux_ops->set_parent(&frac_mux->hw,
157 						  frac->mux_frac_idx);
158 			frac->rate_change_remuxed = 1;
159 		}
160 	} else if (event == POST_RATE_CHANGE) {
161 		/*
162 		 * The POST_RATE_CHANGE notifier runs directly after the
163 		 * divider clock is set in clk_change_rate, so we'll have
164 		 * remuxed back to the original parent before clk_change_rate
165 		 * reaches the mux itself.
166 		 */
167 		if (frac->rate_change_remuxed) {
168 			frac->mux_ops->set_parent(&frac_mux->hw,
169 						  frac->rate_change_idx);
170 			frac->rate_change_remuxed = 0;
171 		}
172 	}
173 
174 	return notifier_from_errno(ret);
175 }
176 
177 /*
178  * fractional divider must set that denominator is 20 times larger than
179  * numerator to generate precise clock frequency.
180  */
181 static void rockchip_fractional_approximation(struct clk_hw *hw,
182 		unsigned long rate, unsigned long *parent_rate,
183 		unsigned long *m, unsigned long *n)
184 {
185 	struct clk_fractional_divider *fd = to_clk_fd(hw);
186 	unsigned long p_rate, p_parent_rate;
187 	struct clk_hw *p_parent;
188 
189 	p_rate = clk_hw_get_rate(clk_hw_get_parent(hw));
190 	if ((rate * 20 > p_rate) && (p_rate % rate != 0)) {
191 		p_parent = clk_hw_get_parent(clk_hw_get_parent(hw));
192 		p_parent_rate = clk_hw_get_rate(p_parent);
193 		*parent_rate = p_parent_rate;
194 	}
195 
196 	fd->flags |= CLK_FRAC_DIVIDER_POWER_OF_TWO_PS;
197 
198 	clk_fractional_divider_general_approximation(hw, rate, parent_rate, m, n);
199 }
200 
201 static struct clk *rockchip_clk_register_frac_branch(
202 		struct rockchip_clk_provider *ctx, const char *name,
203 		const char *const *parent_names, u8 num_parents,
204 		void __iomem *base, int muxdiv_offset, u8 div_flags,
205 		int gate_offset, u8 gate_shift, u8 gate_flags,
206 		unsigned long flags, struct rockchip_clk_branch *child,
207 		spinlock_t *lock)
208 {
209 	struct clk_hw *hw;
210 	struct rockchip_clk_frac *frac;
211 	struct clk_gate *gate = NULL;
212 	struct clk_fractional_divider *div = NULL;
213 	const struct clk_ops *div_ops = NULL, *gate_ops = NULL;
214 
215 	if (muxdiv_offset < 0)
216 		return ERR_PTR(-EINVAL);
217 
218 	if (child && child->branch_type != branch_mux) {
219 		pr_err("%s: fractional child clock for %s can only be a mux\n",
220 		       __func__, name);
221 		return ERR_PTR(-EINVAL);
222 	}
223 
224 	frac = kzalloc(sizeof(*frac), GFP_KERNEL);
225 	if (!frac)
226 		return ERR_PTR(-ENOMEM);
227 
228 	if (gate_offset >= 0) {
229 		gate = &frac->gate;
230 		gate->flags = gate_flags;
231 		gate->reg = base + gate_offset;
232 		gate->bit_idx = gate_shift;
233 		gate->lock = lock;
234 		gate_ops = &clk_gate_ops;
235 	}
236 
237 	div = &frac->div;
238 	div->flags = div_flags;
239 	div->reg = base + muxdiv_offset;
240 	div->mshift = 16;
241 	div->mwidth = 16;
242 	div->mmask = GENMASK(div->mwidth - 1, 0) << div->mshift;
243 	div->nshift = 0;
244 	div->nwidth = 16;
245 	div->nmask = GENMASK(div->nwidth - 1, 0) << div->nshift;
246 	div->lock = lock;
247 	div->approximation = rockchip_fractional_approximation;
248 	div_ops = &clk_fractional_divider_ops;
249 
250 	hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
251 				       NULL, NULL,
252 				       &div->hw, div_ops,
253 				       gate ? &gate->hw : NULL, gate_ops,
254 				       flags | CLK_SET_RATE_UNGATE);
255 	if (IS_ERR(hw)) {
256 		kfree(frac);
257 		return ERR_CAST(hw);
258 	}
259 
260 	if (child) {
261 		struct clk_mux *frac_mux = &frac->mux;
262 		struct clk_init_data init;
263 		struct clk *mux_clk;
264 		int ret;
265 
266 		frac->mux_frac_idx = match_string(child->parent_names,
267 						  child->num_parents, name);
268 		frac->mux_ops = &clk_mux_ops;
269 		frac->clk_nb.notifier_call = rockchip_clk_frac_notifier_cb;
270 
271 		frac_mux->reg = base + child->muxdiv_offset;
272 		frac_mux->shift = child->mux_shift;
273 		frac_mux->mask = BIT(child->mux_width) - 1;
274 		frac_mux->flags = child->mux_flags;
275 		if (child->mux_table)
276 			frac_mux->table = child->mux_table;
277 		frac_mux->lock = lock;
278 		frac_mux->hw.init = &init;
279 
280 		init.name = child->name;
281 		init.flags = child->flags | CLK_SET_RATE_PARENT;
282 		init.ops = frac->mux_ops;
283 		init.parent_names = child->parent_names;
284 		init.num_parents = child->num_parents;
285 
286 		mux_clk = clk_register(NULL, &frac_mux->hw);
287 		if (IS_ERR(mux_clk)) {
288 			kfree(frac);
289 			return mux_clk;
290 		}
291 
292 		rockchip_clk_add_lookup(ctx, mux_clk, child->id);
293 
294 		/* notifier on the fraction divider to catch rate changes */
295 		if (frac->mux_frac_idx >= 0) {
296 			pr_debug("%s: found fractional parent in mux at pos %d\n",
297 				 __func__, frac->mux_frac_idx);
298 			ret = clk_notifier_register(hw->clk, &frac->clk_nb);
299 			if (ret)
300 				pr_err("%s: failed to register clock notifier for %s\n",
301 						__func__, name);
302 		} else {
303 			pr_warn("%s: could not find %s as parent of %s, rate changes may not work\n",
304 				__func__, name, child->name);
305 		}
306 	}
307 
308 	return hw->clk;
309 }
310 
311 static struct clk *rockchip_clk_register_factor_branch(const char *name,
312 		const char *const *parent_names, u8 num_parents,
313 		void __iomem *base, unsigned int mult, unsigned int div,
314 		int gate_offset, u8 gate_shift, u8 gate_flags,
315 		unsigned long flags, spinlock_t *lock)
316 {
317 	struct clk_hw *hw;
318 	struct clk_gate *gate = NULL;
319 	struct clk_fixed_factor *fix = NULL;
320 
321 	/* without gate, register a simple factor clock */
322 	if (gate_offset == 0) {
323 		return clk_register_fixed_factor(NULL, name,
324 				parent_names[0], flags, mult,
325 				div);
326 	}
327 
328 	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
329 	if (!gate)
330 		return ERR_PTR(-ENOMEM);
331 
332 	gate->flags = gate_flags;
333 	gate->reg = base + gate_offset;
334 	gate->bit_idx = gate_shift;
335 	gate->lock = lock;
336 
337 	fix = kzalloc(sizeof(*fix), GFP_KERNEL);
338 	if (!fix) {
339 		kfree(gate);
340 		return ERR_PTR(-ENOMEM);
341 	}
342 
343 	fix->mult = mult;
344 	fix->div = div;
345 
346 	hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
347 				       NULL, NULL,
348 				       &fix->hw, &clk_fixed_factor_ops,
349 				       &gate->hw, &clk_gate_ops, flags);
350 	if (IS_ERR(hw)) {
351 		kfree(fix);
352 		kfree(gate);
353 		return ERR_CAST(hw);
354 	}
355 
356 	return hw->clk;
357 }
358 
359 struct rockchip_clk_provider *rockchip_clk_init(struct device_node *np,
360 						void __iomem *base,
361 						unsigned long nr_clks)
362 {
363 	struct rockchip_clk_provider *ctx;
364 	struct clk **clk_table;
365 	int i;
366 
367 	ctx = kzalloc(sizeof(struct rockchip_clk_provider), GFP_KERNEL);
368 	if (!ctx)
369 		return ERR_PTR(-ENOMEM);
370 
371 	clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL);
372 	if (!clk_table)
373 		goto err_free;
374 
375 	for (i = 0; i < nr_clks; ++i)
376 		clk_table[i] = ERR_PTR(-ENOENT);
377 
378 	ctx->reg_base = base;
379 	ctx->clk_data.clks = clk_table;
380 	ctx->clk_data.clk_num = nr_clks;
381 	ctx->cru_node = np;
382 	spin_lock_init(&ctx->lock);
383 
384 	ctx->grf = syscon_regmap_lookup_by_phandle(ctx->cru_node,
385 						   "rockchip,grf");
386 
387 	return ctx;
388 
389 err_free:
390 	kfree(ctx);
391 	return ERR_PTR(-ENOMEM);
392 }
393 EXPORT_SYMBOL_GPL(rockchip_clk_init);
394 
395 void rockchip_clk_of_add_provider(struct device_node *np,
396 				  struct rockchip_clk_provider *ctx)
397 {
398 	if (of_clk_add_provider(np, of_clk_src_onecell_get,
399 				&ctx->clk_data))
400 		pr_err("%s: could not register clk provider\n", __func__);
401 }
402 EXPORT_SYMBOL_GPL(rockchip_clk_of_add_provider);
403 
404 void rockchip_clk_add_lookup(struct rockchip_clk_provider *ctx,
405 			     struct clk *clk, unsigned int id)
406 {
407 	if (ctx->clk_data.clks && id)
408 		ctx->clk_data.clks[id] = clk;
409 }
410 EXPORT_SYMBOL_GPL(rockchip_clk_add_lookup);
411 
412 void rockchip_clk_register_plls(struct rockchip_clk_provider *ctx,
413 				struct rockchip_pll_clock *list,
414 				unsigned int nr_pll, int grf_lock_offset)
415 {
416 	struct clk *clk;
417 	int idx;
418 
419 	for (idx = 0; idx < nr_pll; idx++, list++) {
420 		clk = rockchip_clk_register_pll(ctx, list->type, list->name,
421 				list->parent_names, list->num_parents,
422 				list->con_offset, grf_lock_offset,
423 				list->lock_shift, list->mode_offset,
424 				list->mode_shift, list->rate_table,
425 				list->flags, list->pll_flags);
426 		if (IS_ERR(clk)) {
427 			pr_err("%s: failed to register clock %s\n", __func__,
428 				list->name);
429 			continue;
430 		}
431 
432 		rockchip_clk_add_lookup(ctx, clk, list->id);
433 	}
434 }
435 EXPORT_SYMBOL_GPL(rockchip_clk_register_plls);
436 
437 void rockchip_clk_register_branches(struct rockchip_clk_provider *ctx,
438 				    struct rockchip_clk_branch *list,
439 				    unsigned int nr_clk)
440 {
441 	struct clk *clk = NULL;
442 	unsigned int idx;
443 	unsigned long flags;
444 
445 	for (idx = 0; idx < nr_clk; idx++, list++) {
446 		flags = list->flags;
447 
448 		/* catch simple muxes */
449 		switch (list->branch_type) {
450 		case branch_mux:
451 			if (list->mux_table)
452 				clk = clk_register_mux_table(NULL, list->name,
453 					list->parent_names, list->num_parents,
454 					flags,
455 					ctx->reg_base + list->muxdiv_offset,
456 					list->mux_shift, list->mux_width,
457 					list->mux_flags, list->mux_table,
458 					&ctx->lock);
459 			else
460 				clk = clk_register_mux(NULL, list->name,
461 					list->parent_names, list->num_parents,
462 					flags,
463 					ctx->reg_base + list->muxdiv_offset,
464 					list->mux_shift, list->mux_width,
465 					list->mux_flags, &ctx->lock);
466 			break;
467 		case branch_muxgrf:
468 			clk = rockchip_clk_register_muxgrf(list->name,
469 				list->parent_names, list->num_parents,
470 				flags, ctx->grf, list->muxdiv_offset,
471 				list->mux_shift, list->mux_width,
472 				list->mux_flags);
473 			break;
474 		case branch_divider:
475 			if (list->div_table)
476 				clk = clk_register_divider_table(NULL,
477 					list->name, list->parent_names[0],
478 					flags,
479 					ctx->reg_base + list->muxdiv_offset,
480 					list->div_shift, list->div_width,
481 					list->div_flags, list->div_table,
482 					&ctx->lock);
483 			else
484 				clk = clk_register_divider(NULL, list->name,
485 					list->parent_names[0], flags,
486 					ctx->reg_base + list->muxdiv_offset,
487 					list->div_shift, list->div_width,
488 					list->div_flags, &ctx->lock);
489 			break;
490 		case branch_fraction_divider:
491 			clk = rockchip_clk_register_frac_branch(ctx, list->name,
492 				list->parent_names, list->num_parents,
493 				ctx->reg_base, list->muxdiv_offset,
494 				list->div_flags,
495 				list->gate_offset, list->gate_shift,
496 				list->gate_flags, flags, list->child,
497 				&ctx->lock);
498 			break;
499 		case branch_half_divider:
500 			clk = rockchip_clk_register_halfdiv(list->name,
501 				list->parent_names, list->num_parents,
502 				ctx->reg_base, list->muxdiv_offset,
503 				list->mux_shift, list->mux_width,
504 				list->mux_flags, list->div_shift,
505 				list->div_width, list->div_flags,
506 				list->gate_offset, list->gate_shift,
507 				list->gate_flags, flags, &ctx->lock);
508 			break;
509 		case branch_gate:
510 			flags |= CLK_SET_RATE_PARENT;
511 
512 			clk = clk_register_gate(NULL, list->name,
513 				list->parent_names[0], flags,
514 				ctx->reg_base + list->gate_offset,
515 				list->gate_shift, list->gate_flags, &ctx->lock);
516 			break;
517 		case branch_composite:
518 			clk = rockchip_clk_register_branch(list->name,
519 				list->parent_names, list->num_parents,
520 				ctx->reg_base, list->muxdiv_offset,
521 				list->mux_shift,
522 				list->mux_width, list->mux_flags,
523 				list->mux_table, list->div_offset,
524 				list->div_shift, list->div_width,
525 				list->div_flags, list->div_table,
526 				list->gate_offset, list->gate_shift,
527 				list->gate_flags, flags, &ctx->lock);
528 			break;
529 		case branch_mmc:
530 			clk = rockchip_clk_register_mmc(
531 				list->name,
532 				list->parent_names, list->num_parents,
533 				ctx->reg_base + list->muxdiv_offset,
534 				list->div_shift
535 			);
536 			break;
537 		case branch_inverter:
538 			clk = rockchip_clk_register_inverter(
539 				list->name, list->parent_names,
540 				list->num_parents,
541 				ctx->reg_base + list->muxdiv_offset,
542 				list->div_shift, list->div_flags, &ctx->lock);
543 			break;
544 		case branch_factor:
545 			clk = rockchip_clk_register_factor_branch(
546 				list->name, list->parent_names,
547 				list->num_parents, ctx->reg_base,
548 				list->div_shift, list->div_width,
549 				list->gate_offset, list->gate_shift,
550 				list->gate_flags, flags, &ctx->lock);
551 			break;
552 		case branch_ddrclk:
553 			clk = rockchip_clk_register_ddrclk(
554 				list->name, list->flags,
555 				list->parent_names, list->num_parents,
556 				list->muxdiv_offset, list->mux_shift,
557 				list->mux_width, list->div_shift,
558 				list->div_width, list->div_flags,
559 				ctx->reg_base, &ctx->lock);
560 			break;
561 		}
562 
563 		/* none of the cases above matched */
564 		if (!clk) {
565 			pr_err("%s: unknown clock type %d\n",
566 			       __func__, list->branch_type);
567 			continue;
568 		}
569 
570 		if (IS_ERR(clk)) {
571 			pr_err("%s: failed to register clock %s: %ld\n",
572 			       __func__, list->name, PTR_ERR(clk));
573 			continue;
574 		}
575 
576 		rockchip_clk_add_lookup(ctx, clk, list->id);
577 	}
578 }
579 EXPORT_SYMBOL_GPL(rockchip_clk_register_branches);
580 
581 void rockchip_clk_register_armclk(struct rockchip_clk_provider *ctx,
582 				  unsigned int lookup_id,
583 				  const char *name, const char *const *parent_names,
584 				  u8 num_parents,
585 				  const struct rockchip_cpuclk_reg_data *reg_data,
586 				  const struct rockchip_cpuclk_rate_table *rates,
587 				  int nrates)
588 {
589 	struct clk *clk;
590 
591 	clk = rockchip_clk_register_cpuclk(name, parent_names, num_parents,
592 					   reg_data, rates, nrates,
593 					   ctx->reg_base, &ctx->lock);
594 	if (IS_ERR(clk)) {
595 		pr_err("%s: failed to register clock %s: %ld\n",
596 		       __func__, name, PTR_ERR(clk));
597 		return;
598 	}
599 
600 	rockchip_clk_add_lookup(ctx, clk, lookup_id);
601 }
602 EXPORT_SYMBOL_GPL(rockchip_clk_register_armclk);
603 
604 void rockchip_clk_protect_critical(const char *const clocks[],
605 				   int nclocks)
606 {
607 	int i;
608 
609 	/* Protect the clocks that needs to stay on */
610 	for (i = 0; i < nclocks; i++) {
611 		struct clk *clk = __clk_lookup(clocks[i]);
612 
613 		clk_prepare_enable(clk);
614 	}
615 }
616 EXPORT_SYMBOL_GPL(rockchip_clk_protect_critical);
617 
618 static void __iomem *rst_base;
619 static unsigned int reg_restart;
620 static void (*cb_restart)(void);
621 static int rockchip_restart_notify(struct notifier_block *this,
622 				   unsigned long mode, void *cmd)
623 {
624 	if (cb_restart)
625 		cb_restart();
626 
627 	writel(0xfdb9, rst_base + reg_restart);
628 	return NOTIFY_DONE;
629 }
630 
631 static struct notifier_block rockchip_restart_handler = {
632 	.notifier_call = rockchip_restart_notify,
633 	.priority = 128,
634 };
635 
636 void
637 rockchip_register_restart_notifier(struct rockchip_clk_provider *ctx,
638 				   unsigned int reg,
639 				   void (*cb)(void))
640 {
641 	int ret;
642 
643 	rst_base = ctx->reg_base;
644 	reg_restart = reg;
645 	cb_restart = cb;
646 	ret = register_restart_handler(&rockchip_restart_handler);
647 	if (ret)
648 		pr_err("%s: cannot register restart handler, %d\n",
649 		       __func__, ret);
650 }
651 EXPORT_SYMBOL_GPL(rockchip_register_restart_notifier);
652