drivers/clk/mediatek/clk-cpumux.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015 Linaro Ltd.
   4  * Author: Pi-Cheng Chen <pi-cheng.chen@linaro.org>
   5  */
   6
   7 #include <linux/clk-provider.h>
   8 #include <linux/container_of.h>
   9 #include <linux/err.h>
  10 #include <linux/mfd/syscon.h>
  11 #include <linux/module.h>
  12 #include <linux/regmap.h>
  13 #include <linux/slab.h>
  14
  15 #include "clk-mtk.h"
  16 #include "clk-cpumux.h"
  17
  18 struct mtk_clk_cpumux {
  19         struct clk_hw   hw;
  20         struct regmap   *regmap;
  21         u32             reg;
  22         u32             mask;
  23         u8              shift;
  24 };
  25
  26 static inline struct mtk_clk_cpumux *to_mtk_clk_cpumux(struct clk_hw *_hw)
  27 {
  28         return container_of(_hw, struct mtk_clk_cpumux, hw);
  29 }
  30
  31 static u8 clk_cpumux_get_parent(struct clk_hw *hw)
  32 {
  33         struct mtk_clk_cpumux *mux = to_mtk_clk_cpumux(hw);
  34         unsigned int val;
  35
  36         regmap_read(mux->regmap, mux->reg, &val);
  37
  38         val >>= mux->shift;
  39         val &= mux->mask;
  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         .determine_rate = clk_hw_determine_rate_no_reparent,
  57         .get_parent = clk_cpumux_get_parent,
  58         .set_parent = clk_cpumux_set_parent,
  59 };
  60
  61 static struct clk_hw *
  62 mtk_clk_register_cpumux(struct device *dev, const struct mtk_composite *mux,
  63                         struct regmap *regmap)
  64 {
  65         struct mtk_clk_cpumux *cpumux;
  66         int ret;
  67         struct clk_init_data init;
  68
  69         cpumux = kzalloc(sizeof(*cpumux), GFP_KERNEL);
  70         if (!cpumux)
  71                 return ERR_PTR(-ENOMEM);
  72
  73         init.name = mux->name;
  74         init.ops = &clk_cpumux_ops;
  75         init.parent_names = mux->parent_names;
  76         init.num_parents = mux->num_parents;
  77         init.flags = mux->flags;
  78
  79         cpumux->reg = mux->mux_reg;
  80         cpumux->shift = mux->mux_shift;
  81         cpumux->mask = BIT(mux->mux_width) - 1;
  82         cpumux->regmap = regmap;
  83         cpumux->hw.init = &init;
  84
  85         ret = clk_hw_register(dev, &cpumux->hw);
  86         if (ret) {
  87                 kfree(cpumux);
  88                 return ERR_PTR(ret);
  89         }
  90
  91         return &cpumux->hw;
  92 }
  93
  94 static void mtk_clk_unregister_cpumux(struct clk_hw *hw)
  95 {
  96         struct mtk_clk_cpumux *cpumux;
  97         if (!hw)
  98                 return;
  99
 100         cpumux = to_mtk_clk_cpumux(hw);
 101
 102         clk_hw_unregister(hw);
 103         kfree(cpumux);
 104 }
 105
 106 int mtk_clk_register_cpumuxes(struct device *dev, struct device_node *node,
 107                               const struct mtk_composite *clks, int num,
 108                               struct clk_hw_onecell_data *clk_data)
 109 {
 110         int i;
 111         struct clk_hw *hw;
 112         struct regmap *regmap;
 113
 114         regmap = device_node_to_regmap(node);
 115         if (IS_ERR(regmap)) {
 116                 pr_err("Cannot find regmap for %pOF: %pe\n", node, regmap);
 117                 return PTR_ERR(regmap);
 118         }
 119
 120         for (i = 0; i < num; i++) {
 121                 const struct mtk_composite *mux = &clks[i];
 122
 123                 if (!IS_ERR_OR_NULL(clk_data->hws[mux->id])) {
 124                         pr_warn("%pOF: Trying to register duplicate clock ID: %d\n",
 125                                 node, mux->id);
 126                         continue;
 127                 }
 128
 129                 hw = mtk_clk_register_cpumux(dev, mux, regmap);
 130                 if (IS_ERR(hw)) {
 131                         pr_err("Failed to register clk %s: %pe\n", mux->name,
 132                                hw);
 133                         goto err;
 134                 }
 135
 136                 clk_data->hws[mux->id] = hw;
 137         }
 138
 139         return 0;
 140
 141 err:
 142         while (--i >= 0) {
 143                 const struct mtk_composite *mux = &clks[i];
 144
 145                 if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
 146                         continue;
 147
 148                 mtk_clk_unregister_cpumux(clk_data->hws[mux->id]);
 149                 clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
 150         }
 151
 152         return PTR_ERR(hw);
 153 }
 154 EXPORT_SYMBOL_GPL(mtk_clk_register_cpumuxes);
 155
 156 void mtk_clk_unregister_cpumuxes(const struct mtk_composite *clks, int num,
 157                                  struct clk_hw_onecell_data *clk_data)
 158 {
 159         int i;
 160
 161         for (i = num; i > 0; i--) {
 162                 const struct mtk_composite *mux = &clks[i - 1];
 163
 164                 if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
 165                         continue;
 166
 167                 mtk_clk_unregister_cpumux(clk_data->hws[mux->id]);
 168                 clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
 169         }
 170 }
 171 EXPORT_SYMBOL_GPL(mtk_clk_unregister_cpumuxes);
 172
 173 MODULE_LICENSE("GPL");