1 files changed, 257 insertions, 104 deletions

diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
index c3ad92965823..2601df3b1066 100644
--- a/drivers/clk/rockchip/clk.c
+++ b/drivers/clk/rockchip/clk.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (c) 2014 MundoReader S.L.
  * Author: Heiko Stuebner <heiko@sntech.de>
@@ -11,28 +12,21 @@
  * Copyright (c) 2013 Samsung Electronics Co., Ltd.
  * Copyright (c) 2013 Linaro Ltd.
  * Author: Thomas Abraham <thomas.ab@samsung.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
  */
 
 #include <linux/slab.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
+#include <linux/io.h>
 #include <linux/mfd/syscon.h>
+#include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/reboot.h>
-#include <linux/rational.h>
+
+#include "../clk-fractional-divider.h"
 #include "clk.h"
 
-/**
+/*
  * Register a clock branch.
  * Most clock branches have a form like
  *
@@ -46,12 +40,13 @@ static struct clk *rockchip_clk_register_branch(const char *name,
 		const char *const *parent_names, u8 num_parents,
 		void __iomem *base,
 		int muxdiv_offset, u8 mux_shift, u8 mux_width, u8 mux_flags,
-		u8 div_shift, u8 div_width, u8 div_flags,
+		u32 *mux_table,
+		int div_offset, u8 div_shift, u8 div_width, u8 div_flags,
 		struct clk_div_table *div_table, int gate_offset,
 		u8 gate_shift, u8 gate_flags, unsigned long flags,
 		spinlock_t *lock)
 {
-	struct clk *clk;
+	struct clk_hw *hw;
 	struct clk_mux *mux = NULL;
 	struct clk_gate *gate = NULL;
 	struct clk_divider *div = NULL;
@@ -68,6 +63,7 @@ static struct clk *rockchip_clk_register_branch(const char *name,
 		mux->shift = mux_shift;
 		mux->mask = BIT(mux_width) - 1;
 		mux->flags = mux_flags;
+		mux->table = mux_table;
 		mux->lock = lock;
 		mux_ops = (mux_flags & CLK_MUX_READ_ONLY) ? &clk_mux_ro_ops
 							: &clk_mux_ops;
@@ -95,7 +91,10 @@ static struct clk *rockchip_clk_register_branch(const char *name,
 		}
 
 		div->flags = div_flags;
-		div->reg = base + muxdiv_offset;
+		if (div_offset)
+			div->reg = base + div_offset;
+		else
+			div->reg = base + muxdiv_offset;
 		div->shift = div_shift;
 		div->width = div_width;
 		div->lock = lock;
@@ -105,20 +104,18 @@ static struct clk *rockchip_clk_register_branch(const char *name,
 						: &clk_divider_ops;
 	}
 
-	clk = clk_register_composite(NULL, name, parent_names, num_parents,
-				     mux ? &mux->hw : NULL, mux_ops,
-				     div ? &div->hw : NULL, div_ops,
-				     gate ? &gate->hw : NULL, gate_ops,
-				     flags);
-
-	if (IS_ERR(clk)) {
-		ret = PTR_ERR(clk);
-		goto err_composite;
+	hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
+				       mux ? &mux->hw : NULL, mux_ops,
+				       div ? &div->hw : NULL, div_ops,
+				       gate ? &gate->hw : NULL, gate_ops,
+				       flags);
+	if (IS_ERR(hw)) {
+		kfree(div);
+		kfree(gate);
+		return ERR_CAST(hw);
 	}
 
-	return clk;
-err_composite:
-	kfree(div);
+	return hw->clk;
 err_div:
 	kfree(gate);
 err_gate:
@@ -177,7 +174,7 @@ static int rockchip_clk_frac_notifier_cb(struct notifier_block *nb,
 	return notifier_from_errno(ret);
 }
 
-/**
+/*
  * fractional divider must set that denominator is 20 times larger than
  * numerator to generate precise clock frequency.
  */
@@ -188,7 +185,6 @@ static void rockchip_fractional_approximation(struct clk_hw *hw,
 	struct clk_fractional_divider *fd = to_clk_fd(hw);
 	unsigned long p_rate, p_parent_rate;
 	struct clk_hw *p_parent;
-	unsigned long scale;
 
 	p_rate = clk_hw_get_rate(clk_hw_get_parent(hw));
 	if ((rate * 20 > p_rate) && (p_rate % rate != 0)) {
@@ -197,18 +193,9 @@ static void rockchip_fractional_approximation(struct clk_hw *hw,
 		*parent_rate = p_parent_rate;
 	}
 
-	/*
-	 * Get rate closer to *parent_rate to guarantee there is no overflow
-	 * for m and n. In the result it will be the nearest rate left shifted
-	 * by (scale - fd->nwidth) bits.
-	 */
-	scale = fls_long(*parent_rate / rate - 1);
-	if (scale > fd->nwidth)
-		rate <<= scale - fd->nwidth;
-
-	rational_best_approximation(rate, *parent_rate,
-			GENMASK(fd->mwidth - 1, 0), GENMASK(fd->nwidth - 1, 0),
-			m, n);
+	fd->flags |= CLK_FRAC_DIVIDER_POWER_OF_TWO_PS;
+
+	clk_fractional_divider_general_approximation(hw, rate, parent_rate, m, n);
 }
 
 static struct clk *rockchip_clk_register_frac_branch(
@@ -219,8 +206,8 @@ static struct clk *rockchip_clk_register_frac_branch(
 		unsigned long flags, struct rockchip_clk_branch *child,
 		spinlock_t *lock)
 {
+	struct clk_hw *hw;
 	struct rockchip_clk_frac *frac;
-	struct clk *clk;
 	struct clk_gate *gate = NULL;
 	struct clk_fractional_divider *div = NULL;
 	const struct clk_ops *div_ops = NULL, *gate_ops = NULL;
@@ -252,22 +239,20 @@ static struct clk *rockchip_clk_register_frac_branch(
 	div->reg = base + muxdiv_offset;
 	div->mshift = 16;
 	div->mwidth = 16;
-	div->mmask = GENMASK(div->mwidth - 1, 0) << div->mshift;
 	div->nshift = 0;
 	div->nwidth = 16;
-	div->nmask = GENMASK(div->nwidth - 1, 0) << div->nshift;
 	div->lock = lock;
 	div->approximation = rockchip_fractional_approximation;
 	div_ops = &clk_fractional_divider_ops;
 
-	clk = clk_register_composite(NULL, name, parent_names, num_parents,
-				     NULL, NULL,
-				     &div->hw, div_ops,
-				     gate ? &gate->hw : NULL, gate_ops,
-				     flags | CLK_SET_RATE_UNGATE);
-	if (IS_ERR(clk)) {
+	hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
+				       NULL, NULL,
+				       &div->hw, div_ops,
+				       gate ? &gate->hw : NULL, gate_ops,
+				       flags | CLK_SET_RATE_UNGATE);
+	if (IS_ERR(hw)) {
 		kfree(frac);
-		return clk;
+		return ERR_CAST(hw);
 	}
 
 	if (child) {
@@ -285,6 +270,8 @@ static struct clk *rockchip_clk_register_frac_branch(
 		frac_mux->shift = child->mux_shift;
 		frac_mux->mask = BIT(child->mux_width) - 1;
 		frac_mux->flags = child->mux_flags;
+		if (child->mux_table)
+			frac_mux->table = child->mux_table;
 		frac_mux->lock = lock;
 		frac_mux->hw.init = &init;
 
@@ -297,16 +284,16 @@ static struct clk *rockchip_clk_register_frac_branch(
 		mux_clk = clk_register(NULL, &frac_mux->hw);
 		if (IS_ERR(mux_clk)) {
 			kfree(frac);
-			return clk;
+			return mux_clk;
 		}
 
-		rockchip_clk_add_lookup(ctx, mux_clk, child->id);
+		rockchip_clk_set_lookup(ctx, mux_clk, child->id);
 
 		/* notifier on the fraction divider to catch rate changes */
 		if (frac->mux_frac_idx >= 0) {
 			pr_debug("%s: found fractional parent in mux at pos %d\n",
 				 __func__, frac->mux_frac_idx);
-			ret = clk_notifier_register(clk, &frac->clk_nb);
+			ret = clk_notifier_register(hw->clk, &frac->clk_nb);
 			if (ret)
 				pr_err("%s: failed to register clock notifier for %s\n",
 						__func__, name);
@@ -316,7 +303,7 @@ static struct clk *rockchip_clk_register_frac_branch(
 		}
 	}
 
-	return clk;
+	return hw->clk;
 }
 
 static struct clk *rockchip_clk_register_factor_branch(const char *name,
@@ -325,7 +312,7 @@ static struct clk *rockchip_clk_register_factor_branch(const char *name,
 		int gate_offset, u8 gate_shift, u8 gate_flags,
 		unsigned long flags, spinlock_t *lock)
 {
-	struct clk *clk;
+	struct clk_hw *hw;
 	struct clk_gate *gate = NULL;
 	struct clk_fixed_factor *fix = NULL;
 
@@ -354,25 +341,30 @@ static struct clk *rockchip_clk_register_factor_branch(const char *name,
 	fix->mult = mult;
 	fix->div = div;
 
-	clk = clk_register_composite(NULL, name, parent_names, num_parents,
-				     NULL, NULL,
-				     &fix->hw, &clk_fixed_factor_ops,
-				     &gate->hw, &clk_gate_ops, flags);
-	if (IS_ERR(clk)) {
+	hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
+				       NULL, NULL,
+				       &fix->hw, &clk_fixed_factor_ops,
+				       &gate->hw, &clk_gate_ops, flags);
+	if (IS_ERR(hw)) {
 		kfree(fix);
 		kfree(gate);
+		return ERR_CAST(hw);
 	}
 
-	return clk;
+	return hw->clk;
 }
 
-struct rockchip_clk_provider * __init rockchip_clk_init(struct device_node *np,
-			void __iomem *base, unsigned long nr_clks)
+static struct rockchip_clk_provider *rockchip_clk_init_base(
+		struct device_node *np, void __iomem *base,
+		unsigned long nr_clks, bool has_late_clocks)
 {
 	struct rockchip_clk_provider *ctx;
 	struct clk **clk_table;
+	struct clk *default_clk_val;
 	int i;
 
+	default_clk_val = ERR_PTR(has_late_clocks ? -EPROBE_DEFER : -ENOENT);
+
 	ctx = kzalloc(sizeof(struct rockchip_clk_provider), GFP_KERNEL);
 	if (!ctx)
 		return ERR_PTR(-ENOMEM);
@@ -382,7 +374,7 @@ struct rockchip_clk_provider * __init rockchip_clk_init(struct device_node *np,
 		goto err_free;
 
 	for (i = 0; i < nr_clks; ++i)
-		clk_table[i] = ERR_PTR(-ENOENT);
+		clk_table[i] = default_clk_val;
 
 	ctx->reg_base = base;
 	ctx->clk_data.clks = clk_table;
@@ -390,6 +382,8 @@ struct rockchip_clk_provider * __init rockchip_clk_init(struct device_node *np,
 	ctx->cru_node = np;
 	spin_lock_init(&ctx->lock);
 
+	hash_init(ctx->aux_grf_table);
+
 	ctx->grf = syscon_regmap_lookup_by_phandle(ctx->cru_node,
 						   "rockchip,grf");
 
@@ -400,22 +394,42 @@ err_free:
 	return ERR_PTR(-ENOMEM);
 }
 
-void __init rockchip_clk_of_add_provider(struct device_node *np,
-				struct rockchip_clk_provider *ctx)
+struct rockchip_clk_provider *rockchip_clk_init(struct device_node *np,
+						void __iomem *base,
+						unsigned long nr_clks)
 {
-	if (of_clk_add_provider(np, of_clk_src_onecell_get,
-				&ctx->clk_data))
-		pr_err("%s: could not register clk provider\n", __func__);
+	return rockchip_clk_init_base(np, base, nr_clks, false);
+}
+EXPORT_SYMBOL_GPL(rockchip_clk_init);
+
+struct rockchip_clk_provider *rockchip_clk_init_early(struct device_node *np,
+						      void __iomem *base,
+						      unsigned long nr_clks)
+{
+	return rockchip_clk_init_base(np, base, nr_clks, true);
 }
+EXPORT_SYMBOL_GPL(rockchip_clk_init_early);
 
-void rockchip_clk_add_lookup(struct rockchip_clk_provider *ctx,
-			     struct clk *clk, unsigned int id)
+void rockchip_clk_finalize(struct rockchip_clk_provider *ctx)
 {
-	if (ctx->clk_data.clks && id)
-		ctx->clk_data.clks[id] = clk;
+	int i;
+
+	for (i = 0; i < ctx->clk_data.clk_num; ++i)
+		if (ctx->clk_data.clks[i] == ERR_PTR(-EPROBE_DEFER))
+			ctx->clk_data.clks[i] = ERR_PTR(-ENOENT);
 }
+EXPORT_SYMBOL_GPL(rockchip_clk_finalize);
 
-void __init rockchip_clk_register_plls(struct rockchip_clk_provider *ctx,
+void rockchip_clk_of_add_provider(struct device_node *np,
+				  struct rockchip_clk_provider *ctx)
+{
+	if (of_clk_add_provider(np, of_clk_src_onecell_get,
+				&ctx->clk_data))
+		pr_err("%s: could not register clk provider\n", __func__);
+}
+EXPORT_SYMBOL_GPL(rockchip_clk_of_add_provider);
+
+void rockchip_clk_register_plls(struct rockchip_clk_provider *ctx,
 				struct rockchip_pll_clock *list,
 				unsigned int nr_pll, int grf_lock_offset)
 {
@@ -435,35 +449,101 @@ void __init rockchip_clk_register_plls(struct rockchip_clk_provider *ctx,
 			continue;
 		}
 
-		rockchip_clk_add_lookup(ctx, clk, list->id);
+		rockchip_clk_set_lookup(ctx, clk, list->id);
 	}
 }
+EXPORT_SYMBOL_GPL(rockchip_clk_register_plls);
 
-void __init rockchip_clk_register_branches(
-				      struct rockchip_clk_provider *ctx,
-				      struct rockchip_clk_branch *list,
-				      unsigned int nr_clk)
+unsigned long rockchip_clk_find_max_clk_id(struct rockchip_clk_branch *list,
+					   unsigned int nr_clk)
 {
-	struct clk *clk = NULL;
+	unsigned long max = 0;
+	unsigned int idx;
+
+	for (idx = 0; idx < nr_clk; idx++, list++) {
+		if (list->id > max)
+			max = list->id;
+		if (list->child && list->child->id > max)
+			max = list->child->id;
+	}
+
+	return max;
+}
+EXPORT_SYMBOL_GPL(rockchip_clk_find_max_clk_id);
+
+static struct platform_device *rockchip_clk_register_gate_link(
+		struct device *parent_dev,
+		struct rockchip_clk_provider *ctx,
+		struct rockchip_clk_branch *clkbr)
+{
+	struct rockchip_gate_link_platdata gate_link_pdata = {
+		.ctx = ctx,
+		.clkbr = clkbr,
+	};
+
+	struct platform_device_info pdevinfo = {
+		.parent = parent_dev,
+		.name = "rockchip-gate-link-clk",
+		.id = clkbr->id,
+		.fwnode = dev_fwnode(parent_dev),
+		.of_node_reused = true,
+		.data = &gate_link_pdata,
+		.size_data = sizeof(gate_link_pdata),
+	};
+
+	return platform_device_register_full(&pdevinfo);
+}
+
+void rockchip_clk_register_branches(struct rockchip_clk_provider *ctx,
+				    struct rockchip_clk_branch *list,
+				    unsigned int nr_clk)
+{
+	struct regmap *grf = ctx->grf;
+	struct rockchip_aux_grf *agrf;
+	struct clk *clk;
 	unsigned int idx;
 	unsigned long flags;
 
 	for (idx = 0; idx < nr_clk; idx++, list++) {
 		flags = list->flags;
+		clk = NULL;
+
+		/* for GRF-dependent branches, choose the right grf first */
+		if ((list->branch_type == branch_grf_mux ||
+		     list->branch_type == branch_grf_gate ||
+		     list->branch_type == branch_grf_mmc) &&
+		    list->grf_type != grf_type_sys) {
+			hash_for_each_possible(ctx->aux_grf_table, agrf, node, list->grf_type) {
+				if (agrf->type == list->grf_type) {
+					grf = agrf->grf;
+					break;
+				}
+			}
+		}
 
 		/* catch simple muxes */
 		switch (list->branch_type) {
 		case branch_mux:
-			clk = clk_register_mux(NULL, list->name,
-				list->parent_names, list->num_parents,
-				flags, ctx->reg_base + list->muxdiv_offset,
-				list->mux_shift, list->mux_width,
-				list->mux_flags, &ctx->lock);
+			if (list->mux_table)
+				clk = clk_register_mux_table(NULL, list->name,
+					list->parent_names, list->num_parents,
+					flags,
+					ctx->reg_base + list->muxdiv_offset,
+					list->mux_shift, list->mux_width,
+					list->mux_flags, list->mux_table,
+					&ctx->lock);
+			else
+				clk = clk_register_mux(NULL, list->name,
+					list->parent_names, list->num_parents,
+					flags,
+					ctx->reg_base + list->muxdiv_offset,
+					list->mux_shift, list->mux_width,
+					list->mux_flags, &ctx->lock);
 			break;
-		case branch_muxgrf:
+		case branch_grf_mux:
 			clk = rockchip_clk_register_muxgrf(list->name,
 				list->parent_names, list->num_parents,
-				flags, ctx->grf, list->muxdiv_offset,
+				flags, grf, list->muxdiv_offset,
 				list->mux_shift, list->mux_width,
 				list->mux_flags);
 			break;
@@ -510,12 +590,20 @@ void __init rockchip_clk_register_branches(
 				ctx->reg_base + list->gate_offset,
 				list->gate_shift, list->gate_flags, &ctx->lock);
 			break;
+		case branch_grf_gate:
+			flags |= CLK_SET_RATE_PARENT;
+			clk = rockchip_clk_register_gate_grf(list->name,
+				list->parent_names[0], flags, grf,
+				list->gate_offset, list->gate_shift,
+				list->gate_flags);
+			break;
 		case branch_composite:
 			clk = rockchip_clk_register_branch(list->name,
 				list->parent_names, list->num_parents,
 				ctx->reg_base, list->muxdiv_offset,
 				list->mux_shift,
 				list->mux_width, list->mux_flags,
+				list->mux_table, list->div_offset,
 				list->div_shift, list->div_width,
 				list->div_flags, list->div_table,
 				list->gate_offset, list->gate_shift,
@@ -526,6 +614,16 @@ void __init rockchip_clk_register_branches(
 				list->name,
 				list->parent_names, list->num_parents,
 				ctx->reg_base + list->muxdiv_offset,
+				NULL, 0,
+				list->div_shift
+			);
+			break;
+		case branch_grf_mmc:
+			clk = rockchip_clk_register_mmc(
+				list->name,
+				list->parent_names, list->num_parents,
+				NULL,
+				grf, list->muxdiv_offset,
 				list->div_shift
 			);
 			break;
@@ -553,6 +651,9 @@ void __init rockchip_clk_register_branches(
 				list->div_width, list->div_flags,
 				ctx->reg_base, &ctx->lock);
 			break;
+		case branch_linked_gate:
+			/* must be registered late, fall-through for error message */
+			break;
 		}
 
 		/* none of the cases above matched */
@@ -568,17 +669,43 @@ void __init rockchip_clk_register_branches(
 			continue;
 		}
 
-		rockchip_clk_add_lookup(ctx, clk, list->id);
+		rockchip_clk_set_lookup(ctx, clk, list->id);
 	}
 }
+EXPORT_SYMBOL_GPL(rockchip_clk_register_branches);
 
-void __init rockchip_clk_register_armclk(struct rockchip_clk_provider *ctx,
-			unsigned int lookup_id,
-			const char *name, const char *const *parent_names,
-			u8 num_parents,
-			const struct rockchip_cpuclk_reg_data *reg_data,
-			const struct rockchip_cpuclk_rate_table *rates,
-			int nrates)
+void rockchip_clk_register_late_branches(struct device *dev,
+					 struct rockchip_clk_provider *ctx,
+					 struct rockchip_clk_branch *list,
+					 unsigned int nr_clk)
+{
+	unsigned int idx;
+
+	for (idx = 0; idx < nr_clk; idx++, list++) {
+		struct platform_device *pdev = NULL;
+
+		switch (list->branch_type) {
+		case branch_linked_gate:
+			pdev = rockchip_clk_register_gate_link(dev, ctx, list);
+			break;
+		default:
+			dev_err(dev, "unknown clock type %d\n", list->branch_type);
+			break;
+		}
+
+		if (!pdev)
+			dev_err(dev, "failed to register device for clock %s\n", list->name);
+	}
+}
+EXPORT_SYMBOL_GPL(rockchip_clk_register_late_branches);
+
+void rockchip_clk_register_armclk(struct rockchip_clk_provider *ctx,
+				  unsigned int lookup_id,
+				  const char *name, const char *const *parent_names,
+				  u8 num_parents,
+				  const struct rockchip_cpuclk_reg_data *reg_data,
+				  const struct rockchip_cpuclk_rate_table *rates,
+				  int nrates)
 {
 	struct clk *clk;
 
@@ -591,11 +718,36 @@ void __init rockchip_clk_register_armclk(struct rockchip_clk_provider *ctx,
 		return;
 	}
 
-	rockchip_clk_add_lookup(ctx, clk, lookup_id);
+	rockchip_clk_set_lookup(ctx, clk, lookup_id);
+}
+EXPORT_SYMBOL_GPL(rockchip_clk_register_armclk);
+
+void rockchip_clk_register_armclk_multi_pll(struct rockchip_clk_provider *ctx,
+					    struct rockchip_clk_branch *list,
+					    const struct rockchip_cpuclk_rate_table *rates,
+					    int nrates)
+{
+	struct clk *clk;
+
+	clk = rockchip_clk_register_cpuclk_multi_pll(list->name, list->parent_names,
+						     list->num_parents, ctx->reg_base,
+						     list->muxdiv_offset, list->mux_shift,
+						     list->mux_width, list->mux_flags,
+						     list->div_offset, list->div_shift,
+						     list->div_width, list->div_flags,
+						     list->flags, &ctx->lock, rates, nrates);
+	if (IS_ERR(clk)) {
+		pr_err("%s: failed to register clock %s: %ld\n",
+		       __func__, list->name, PTR_ERR(clk));
+		return;
+	}
+
+	rockchip_clk_set_lookup(ctx, clk, list->id);
 }
+EXPORT_SYMBOL_GPL(rockchip_clk_register_armclk_multi_pll);
 
-void __init rockchip_clk_protect_critical(const char *const clocks[],
-					  int nclocks)
+void rockchip_clk_protect_critical(const char *const clocks[],
+				   int nclocks)
 {
 	int i;
 
@@ -603,10 +755,10 @@ void __init rockchip_clk_protect_critical(const char *const clocks[],
 	for (i = 0; i < nclocks; i++) {
 		struct clk *clk = __clk_lookup(clocks[i]);
 
-		if (clk)
-			clk_prepare_enable(clk);
+		clk_prepare_enable(clk);
 	}
 }
+EXPORT_SYMBOL_GPL(rockchip_clk_protect_critical);
 
 static void __iomem *rst_base;
 static unsigned int reg_restart;
@@ -626,10 +778,10 @@ static struct notifier_block rockchip_restart_handler = {
 	.priority = 128,
 };
 
-void __init
+void
 rockchip_register_restart_notifier(struct rockchip_clk_provider *ctx,
-					       unsigned int reg,
-					       void (*cb)(void))
+				   unsigned int reg,
+				   void (*cb)(void))
 {
 	int ret;
 
@@ -641,3 +793,4 @@ rockchip_register_restart_notifier(struct rockchip_clk_provider *ctx,
 		pr_err("%s: cannot register restart handler, %d\n",
 		       __func__, ret);
 }
+EXPORT_SYMBOL_GPL(rockchip_register_restart_notifier);