linux/drivers/clk/uniphier/clk-uniphier-mux.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (C) 2016 Socionext Inc.
   4 *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
   5 */
   6
   7#include <linux/clk-provider.h>
   8#include <linux/device.h>
   9#include <linux/regmap.h>
  10
  11#include "clk-uniphier.h"
  12
  13struct uniphier_clk_mux {
  14        struct clk_hw hw;
  15        struct regmap *regmap;
  16        unsigned int reg;
  17        const unsigned int *masks;
  18        const unsigned int *vals;
  19};
  20
  21#define to_uniphier_clk_mux(_hw) container_of(_hw, struct uniphier_clk_mux, hw)
  22
  23static int uniphier_clk_mux_set_parent(struct clk_hw *hw, u8 index)
  24{
  25        struct uniphier_clk_mux *mux = to_uniphier_clk_mux(hw);
  26
  27        return regmap_write_bits(mux->regmap, mux->reg, mux->masks[index],
  28                                 mux->vals[index]);
  29}
  30
  31static u8 uniphier_clk_mux_get_parent(struct clk_hw *hw)
  32{
  33        struct uniphier_clk_mux *mux = to_uniphier_clk_mux(hw);
  34        unsigned int num_parents = clk_hw_get_num_parents(hw);
  35        int ret;
  36        unsigned int val;
  37        unsigned int i;
  38
  39        ret = regmap_read(mux->regmap, mux->reg, &val);
  40        if (ret)
  41                return ret;
  42
  43        for (i = 0; i < num_parents; i++)
  44                if ((mux->masks[i] & val) == mux->vals[i])
  45                        return i;
  46
  47        return -EINVAL;
  48}
  49
  50static const struct clk_ops uniphier_clk_mux_ops = {
  51        .determine_rate = __clk_mux_determine_rate,
  52        .set_parent = uniphier_clk_mux_set_parent,
  53        .get_parent = uniphier_clk_mux_get_parent,
  54};
  55
  56struct clk_hw *uniphier_clk_register_mux(struct device *dev,
  57                                         struct regmap *regmap,
  58                                         const char *name,
  59                                const struct uniphier_clk_mux_data *data)
  60{
  61        struct uniphier_clk_mux *mux;
  62        struct clk_init_data init;
  63        int ret;
  64
  65        mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
  66        if (!mux)
  67                return ERR_PTR(-ENOMEM);
  68
  69        init.name = name;
  70        init.ops = &uniphier_clk_mux_ops;
  71        init.flags = CLK_SET_RATE_PARENT;
  72        init.parent_names = data->parent_names;
  73        init.num_parents = data->num_parents;
  74
  75        mux->regmap = regmap;
  76        mux->reg = data->reg;
  77        mux->masks = data->masks;
  78        mux->vals = data->vals;
  79        mux->hw.init = &init;
  80
  81        ret = devm_clk_hw_register(dev, &mux->hw);
  82        if (ret)
  83                return ERR_PTR(ret);
  84
  85        return &mux->hw;
  86}
  87