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         unsigned int val;
  31
  32         regmap_read(mux->regmap, mux->reg, &val);
  33
  34         val >>= mux->shift;
  35         val &= mux->mask;
  36
  37         return val;
  38 }
  39
  40 static int clk_cpumux_set_parent(struct clk_hw *hw, u8 index)
  41 {
  42         struct mtk_clk_cpumux *mux = to_mtk_clk_cpumux(hw);
  43         u32 mask, val;
  44
  45         val = index << mux->shift;
  46         mask = mux->mask << mux->shift;
  47
  48         return regmap_update_bits(mux->regmap, mux->reg, mask, val);
  49 }
  50
  51 static const struct clk_ops clk_cpumux_ops = {
  52         .get_parent = clk_cpumux_get_parent,
  53         .set_parent = clk_cpumux_set_parent,
  54 };
  55
  56 static struct clk *
  57 mtk_clk_register_cpumux(const struct mtk_composite *mux,
  58                         struct regmap *regmap)
  59 {
  60         struct mtk_clk_cpumux *cpumux;
  61         struct clk *clk;
  62         struct clk_init_data init;
  63
  64         cpumux = kzalloc(sizeof(*cpumux), GFP_KERNEL);
  65         if (!cpumux)
  66                 return ERR_PTR(-ENOMEM);
  67
  68         init.name = mux->name;
  69         init.ops = &clk_cpumux_ops;
  70         init.parent_names = mux->parent_names;
  71         init.num_parents = mux->num_parents;
  72         init.flags = mux->flags;
  73
  74         cpumux->reg = mux->mux_reg;
  75         cpumux->shift = mux->mux_shift;
  76         cpumux->mask = BIT(mux->mux_width) - 1;
  77         cpumux->regmap = regmap;
  78         cpumux->hw.init = &init;
  79
  80         clk = clk_register(NULL, &cpumux->hw);
  81         if (IS_ERR(clk))
  82                 kfree(cpumux);
  83
  84         return clk;
  85 }
  86
  87 int mtk_clk_register_cpumuxes(struct device_node *node,
  88                               const struct mtk_composite *clks, int num,
  89                               struct clk_onecell_data *clk_data)
  90 {
  91         int i;
  92         struct clk *clk;
  93         struct regmap *regmap;
  94
  95         regmap = syscon_node_to_regmap(node);
  96         if (IS_ERR(regmap)) {
  97                 pr_err("Cannot find regmap for %pOF: %ld\n", node,
  98                        PTR_ERR(regmap));
  99                 return PTR_ERR(regmap);
 100         }
 101
 102         for (i = 0; i < num; i++) {
 103                 const struct mtk_composite *mux = &clks[i];
 104
 105                 clk = mtk_clk_register_cpumux(mux, regmap);
 106                 if (IS_ERR(clk)) {
 107                         pr_err("Failed to register clk %s: %ld\n",
 108                                mux->name, PTR_ERR(clk));
 109                         continue;
 110                 }
 111
 112                 clk_data->clks[mux->id] = clk;
 113         }
 114
 115         return 0;
 116 }