311 lines
7.1 KiB
C
311 lines
7.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2018 MediaTek Inc.
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* Author: Owen Chen <owen.chen@mediatek.com>
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*/
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#include <linux/clk.h>
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#include <linux/clk-provider.h>
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#include <linux/compiler_types.h>
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#include <linux/container_of.h>
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#include <linux/err.h>
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#include <linux/mfd/syscon.h>
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#include <linux/module.h>
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#include <linux/regmap.h>
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#include <linux/spinlock.h>
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#include <linux/slab.h>
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#include "clk-mux.h"
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struct mtk_clk_mux {
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struct clk_hw hw;
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struct regmap *regmap;
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const struct mtk_mux *data;
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spinlock_t *lock;
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bool reparent;
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};
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static inline struct mtk_clk_mux *to_mtk_clk_mux(struct clk_hw *hw)
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{
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return container_of(hw, struct mtk_clk_mux, hw);
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}
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static int mtk_clk_mux_enable_setclr(struct clk_hw *hw)
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{
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struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
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unsigned long flags = 0;
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if (mux->lock)
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spin_lock_irqsave(mux->lock, flags);
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else
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__acquire(mux->lock);
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regmap_write(mux->regmap, mux->data->clr_ofs,
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BIT(mux->data->gate_shift));
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/*
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* If the parent has been changed when the clock was disabled, it will
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* not be effective yet. Set the update bit to ensure the mux gets
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* updated.
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*/
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if (mux->reparent && mux->data->upd_shift >= 0) {
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regmap_write(mux->regmap, mux->data->upd_ofs,
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BIT(mux->data->upd_shift));
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mux->reparent = false;
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}
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if (mux->lock)
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spin_unlock_irqrestore(mux->lock, flags);
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else
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__release(mux->lock);
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return 0;
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}
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static void mtk_clk_mux_disable_setclr(struct clk_hw *hw)
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{
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struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
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regmap_write(mux->regmap, mux->data->set_ofs,
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BIT(mux->data->gate_shift));
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}
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static int mtk_clk_mux_is_enabled(struct clk_hw *hw)
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{
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struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
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u32 val;
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regmap_read(mux->regmap, mux->data->mux_ofs, &val);
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return (val & BIT(mux->data->gate_shift)) == 0;
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}
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static u8 mtk_clk_mux_get_parent(struct clk_hw *hw)
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{
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struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
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u32 mask = GENMASK(mux->data->mux_width - 1, 0);
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u32 val;
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regmap_read(mux->regmap, mux->data->mux_ofs, &val);
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val = (val >> mux->data->mux_shift) & mask;
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return val;
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}
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static int mtk_clk_mux_set_parent_setclr_lock(struct clk_hw *hw, u8 index)
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{
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struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
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u32 mask = GENMASK(mux->data->mux_width - 1, 0);
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u32 val, orig;
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unsigned long flags = 0;
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if (mux->lock)
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spin_lock_irqsave(mux->lock, flags);
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else
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__acquire(mux->lock);
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regmap_read(mux->regmap, mux->data->mux_ofs, &orig);
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val = (orig & ~(mask << mux->data->mux_shift))
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| (index << mux->data->mux_shift);
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if (val != orig) {
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regmap_write(mux->regmap, mux->data->clr_ofs,
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mask << mux->data->mux_shift);
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regmap_write(mux->regmap, mux->data->set_ofs,
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index << mux->data->mux_shift);
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if (mux->data->upd_shift >= 0) {
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regmap_write(mux->regmap, mux->data->upd_ofs,
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BIT(mux->data->upd_shift));
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mux->reparent = true;
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}
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}
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if (mux->lock)
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spin_unlock_irqrestore(mux->lock, flags);
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else
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__release(mux->lock);
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return 0;
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}
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static int mtk_clk_mux_determine_rate(struct clk_hw *hw,
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struct clk_rate_request *req)
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{
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struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
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return clk_mux_determine_rate_flags(hw, req, mux->data->flags);
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}
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const struct clk_ops mtk_mux_clr_set_upd_ops = {
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.get_parent = mtk_clk_mux_get_parent,
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.set_parent = mtk_clk_mux_set_parent_setclr_lock,
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.determine_rate = mtk_clk_mux_determine_rate,
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};
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EXPORT_SYMBOL_GPL(mtk_mux_clr_set_upd_ops);
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const struct clk_ops mtk_mux_gate_clr_set_upd_ops = {
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.enable = mtk_clk_mux_enable_setclr,
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.disable = mtk_clk_mux_disable_setclr,
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.is_enabled = mtk_clk_mux_is_enabled,
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.get_parent = mtk_clk_mux_get_parent,
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.set_parent = mtk_clk_mux_set_parent_setclr_lock,
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.determine_rate = mtk_clk_mux_determine_rate,
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};
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EXPORT_SYMBOL_GPL(mtk_mux_gate_clr_set_upd_ops);
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static struct clk_hw *mtk_clk_register_mux(const struct mtk_mux *mux,
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struct regmap *regmap,
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spinlock_t *lock)
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{
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struct mtk_clk_mux *clk_mux;
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struct clk_init_data init = {};
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int ret;
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clk_mux = kzalloc(sizeof(*clk_mux), GFP_KERNEL);
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if (!clk_mux)
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return ERR_PTR(-ENOMEM);
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init.name = mux->name;
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init.flags = mux->flags | CLK_SET_RATE_PARENT;
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init.parent_names = mux->parent_names;
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init.num_parents = mux->num_parents;
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init.ops = mux->ops;
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clk_mux->regmap = regmap;
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clk_mux->data = mux;
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clk_mux->lock = lock;
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clk_mux->hw.init = &init;
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ret = clk_hw_register(NULL, &clk_mux->hw);
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if (ret) {
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kfree(clk_mux);
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return ERR_PTR(ret);
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}
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return &clk_mux->hw;
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}
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static void mtk_clk_unregister_mux(struct clk_hw *hw)
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{
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struct mtk_clk_mux *mux;
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if (!hw)
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return;
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mux = to_mtk_clk_mux(hw);
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clk_hw_unregister(hw);
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kfree(mux);
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}
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int mtk_clk_register_muxes(const struct mtk_mux *muxes,
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int num, struct device_node *node,
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spinlock_t *lock,
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struct clk_hw_onecell_data *clk_data)
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{
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struct regmap *regmap;
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struct clk_hw *hw;
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int i;
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regmap = device_node_to_regmap(node);
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if (IS_ERR(regmap)) {
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pr_err("Cannot find regmap for %pOF: %pe\n", node, regmap);
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return PTR_ERR(regmap);
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}
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for (i = 0; i < num; i++) {
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const struct mtk_mux *mux = &muxes[i];
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if (!IS_ERR_OR_NULL(clk_data->hws[mux->id])) {
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pr_warn("%pOF: Trying to register duplicate clock ID: %d\n",
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node, mux->id);
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continue;
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}
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hw = mtk_clk_register_mux(mux, regmap, lock);
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if (IS_ERR(hw)) {
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pr_err("Failed to register clk %s: %pe\n", mux->name,
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hw);
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goto err;
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}
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clk_data->hws[mux->id] = hw;
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}
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return 0;
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err:
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while (--i >= 0) {
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const struct mtk_mux *mux = &muxes[i];
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if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
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continue;
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mtk_clk_unregister_mux(clk_data->hws[mux->id]);
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clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
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}
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return PTR_ERR(hw);
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}
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EXPORT_SYMBOL_GPL(mtk_clk_register_muxes);
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void mtk_clk_unregister_muxes(const struct mtk_mux *muxes, int num,
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struct clk_hw_onecell_data *clk_data)
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{
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int i;
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if (!clk_data)
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return;
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for (i = num; i > 0; i--) {
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const struct mtk_mux *mux = &muxes[i - 1];
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if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
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continue;
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mtk_clk_unregister_mux(clk_data->hws[mux->id]);
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clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
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}
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}
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EXPORT_SYMBOL_GPL(mtk_clk_unregister_muxes);
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/*
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* This clock notifier is called when the frequency of the parent
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* PLL clock is to be changed. The idea is to switch the parent to a
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* stable clock, such as the main oscillator, while the PLL frequency
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* stabilizes.
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*/
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static int mtk_clk_mux_notifier_cb(struct notifier_block *nb,
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unsigned long event, void *_data)
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{
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struct clk_notifier_data *data = _data;
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struct clk_hw *hw = __clk_get_hw(data->clk);
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struct mtk_mux_nb *mux_nb = to_mtk_mux_nb(nb);
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int ret = 0;
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switch (event) {
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case PRE_RATE_CHANGE:
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mux_nb->original_index = mux_nb->ops->get_parent(hw);
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ret = mux_nb->ops->set_parent(hw, mux_nb->bypass_index);
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break;
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case POST_RATE_CHANGE:
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case ABORT_RATE_CHANGE:
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ret = mux_nb->ops->set_parent(hw, mux_nb->original_index);
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break;
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}
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return notifier_from_errno(ret);
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}
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int devm_mtk_clk_mux_notifier_register(struct device *dev, struct clk *clk,
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struct mtk_mux_nb *mux_nb)
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{
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mux_nb->nb.notifier_call = mtk_clk_mux_notifier_cb;
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return devm_clk_notifier_register(dev, clk, &mux_nb->nb);
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}
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EXPORT_SYMBOL_GPL(devm_mtk_clk_mux_notifier_register);
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MODULE_LICENSE("GPL");
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