drivers/clk/uniphier/clk-uniphier-mux.c

   1 /*
   2  * Copyright (C) 2016 Socionext Inc.
   3  *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/clk-provider.h>
  17 #include <linux/device.h>
  18 #include <linux/regmap.h>
  19
  20 #include "clk-uniphier.h"
  21
  22 struct uniphier_clk_mux {
  23         struct clk_hw hw;
  24         struct regmap *regmap;
  25         unsigned int reg;
  26         const unsigned int *masks;
  27         const unsigned int *vals;
  28 };
  29
  30 #define to_uniphier_clk_mux(_hw) container_of(_hw, struct uniphier_clk_mux, hw)
  31
  32 static int uniphier_clk_mux_set_parent(struct clk_hw *hw, u8 index)
  33 {
  34         struct uniphier_clk_mux *mux = to_uniphier_clk_mux(hw);
  35
  36         return regmap_write_bits(mux->regmap, mux->reg, mux->masks[index],
  37                                  mux->vals[index]);
  38 }
  39
  40 static u8 uniphier_clk_mux_get_parent(struct clk_hw *hw)
  41 {
  42         struct uniphier_clk_mux *mux = to_uniphier_clk_mux(hw);
  43         int num_parents = clk_hw_get_num_parents(hw);
  44         int ret;
  45         unsigned int val;
  46         u8 i;
  47
  48         ret = regmap_read(mux->regmap, mux->reg, &val);
  49         if (ret)
  50                 return ret;
  51
  52         for (i = 0; i < num_parents; i++)
  53                 if ((mux->masks[i] & val) == mux->vals[i])
  54                         return i;
  55
  56         return -EINVAL;
  57 }
  58
  59 static const struct clk_ops uniphier_clk_mux_ops = {
  60         .determine_rate = __clk_mux_determine_rate,
  61         .set_parent = uniphier_clk_mux_set_parent,
  62         .get_parent = uniphier_clk_mux_get_parent,
  63 };
  64
  65 struct clk_hw *uniphier_clk_register_mux(struct device *dev,
  66                                          struct regmap *regmap,
  67                                          const char *name,
  68                                 const struct uniphier_clk_mux_data *data)
  69 {
  70         struct uniphier_clk_mux *mux;
  71         struct clk_init_data init;
  72         int ret;
  73
  74         mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
  75         if (!mux)
  76                 return ERR_PTR(-ENOMEM);
  77
  78         init.name = name;
  79         init.ops = &uniphier_clk_mux_ops;
  80         init.flags = CLK_SET_RATE_PARENT;
  81         init.parent_names = data->parent_names;
  82         init.num_parents = data->num_parents,
  83
  84         mux->regmap = regmap;
  85         mux->reg = data->reg;
  86         mux->masks = data->masks;
  87         mux->vals = data->vals;
  88         mux->hw.init = &init;
  89
  90         ret = devm_clk_hw_register(dev, &mux->hw);
  91         if (ret)
  92                 return ERR_PTR(ret);
  93
  94         return &mux->hw;
  95 }