drivers/clk/mediatek/clk-cpumux.c

   1 /*
   2  * Copyright (c) 2015 Linaro Ltd.
   3  * Author: Pi-Cheng Chen <pi-cheng.chen@linaro.org>
   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 version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/clk-provider.h>
  16 #include <linux/mfd/syscon.h>
  17 #include <linux/slab.h>
  18
  19 #include "clk-mtk.h"
  20 #include "clk-cpumux.h"
  21
  22 static inline struct mtk_clk_cpumux *to_mtk_clk_cpumux(struct clk_hw *_hw)
  23 {
  24         return container_of(_hw, struct mtk_clk_cpumux, hw);
  25 }
  26
  27 static u8 clk_cpumux_get_parent(struct clk_hw *hw)
  28 {
  29         struct mtk_clk_cpumux *mux = to_mtk_clk_cpumux(hw);
  30         int num_parents = clk_hw_get_num_parents(hw);
  31         unsigned int val;
  32
  33         regmap_read(mux->regmap, mux->reg, &val);
  34
  35         val >>= mux->shift;
  36         val &= mux->mask;
  37
  38         if (val >= num_parents)
  39                 return -EINVAL;
  40
  41         return val;
  42 }
  43
  44 static int clk_cpumux_set_parent(struct clk_hw *hw, u8 index)
  45 {
  46         struct mtk_clk_cpumux *mux = to_mtk_clk_cpumux(hw);
  47         u32 mask, val;
  48
  49         val = index << mux->shift;
  50         mask = mux->mask << mux->shift;
  51
  52         return regmap_update_bits(mux->regmap, mux->reg, mask, val);
  53 }
  54
  55 static const struct clk_ops clk_cpumux_ops = {
  56         .get_parent = clk_cpumux_get_parent,
  57         .set_parent = clk_cpumux_set_parent,
  58 };
  59
  60 static struct clk __init *
  61 mtk_clk_register_cpumux(const struct mtk_composite *mux,
  62                         struct regmap *regmap)
  63 {
  64         struct mtk_clk_cpumux *cpumux;
  65         struct clk *clk;
  66         struct clk_init_data init;
  67
  68         cpumux = kzalloc(sizeof(*cpumux), GFP_KERNEL);
  69         if (!cpumux)
  70                 return ERR_PTR(-ENOMEM);
  71
  72         init.name = mux->name;
  73         init.ops = &clk_cpumux_ops;
  74         init.parent_names = mux->parent_names;
  75         init.num_parents = mux->num_parents;
  76         init.flags = mux->flags;
  77
  78         cpumux->reg = mux->mux_reg;
  79         cpumux->shift = mux->mux_shift;
  80         cpumux->mask = BIT(mux->mux_width) - 1;
  81         cpumux->regmap = regmap;
  82         cpumux->hw.init = &init;
  83
  84         clk = clk_register(NULL, &cpumux->hw);
  85         if (IS_ERR(clk))
  86                 kfree(cpumux);
  87
  88         return clk;
  89 }
  90
  91 int __init mtk_clk_register_cpumuxes(struct device_node *node,
  92                                      const struct mtk_composite *clks, int num,
  93                                      struct clk_onecell_data *clk_data)
  94 {
  95         int i;
  96         struct clk *clk;
  97         struct regmap *regmap;
  98
  99         regmap = syscon_node_to_regmap(node);
 100         if (IS_ERR(regmap)) {
 101                 pr_err("Cannot find regmap for %s: %ld\n", node->full_name,
 102                        PTR_ERR(regmap));
 103                 return PTR_ERR(regmap);
 104         }
 105
 106         for (i = 0; i < num; i++) {
 107                 const struct mtk_composite *mux = &clks[i];
 108
 109                 clk = mtk_clk_register_cpumux(mux, regmap);
 110                 if (IS_ERR(clk)) {
 111                         pr_err("Failed to register clk %s: %ld\n",
 112                                mux->name, PTR_ERR(clk));
 113                         continue;
 114                 }
 115
 116                 clk_data->clks[mux->id] = clk;
 117         }
 118
 119         return 0;
 120 }