drivers/clk/mediatek/clk-mux.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2018 MediaTek Inc.
   4  * Author: Owen Chen <owen.chen@mediatek.com>
   5  */
   6
   7 #include <linux/clk-provider.h>
   8 #include <linux/compiler_types.h>
   9 #include <linux/container_of.h>
  10 #include <linux/err.h>
  11 #include <linux/mfd/syscon.h>
  12 #include <linux/module.h>
  13 #include <linux/regmap.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/slab.h>
  16
  17 #include "clk-mux.h"
  18
  19 struct mtk_clk_mux {
  20         struct clk_hw hw;
  21         struct regmap *regmap;
  22         const struct mtk_mux *data;
  23         spinlock_t *lock;
  24         bool reparent;
  25 };
  26
  27 static inline struct mtk_clk_mux *to_mtk_clk_mux(struct clk_hw *hw)
  28 {
  29         return container_of(hw, struct mtk_clk_mux, hw);
  30 }
  31
  32 static int mtk_clk_mux_enable_setclr(struct clk_hw *hw)
  33 {
  34         struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
  35         unsigned long flags = 0;
  36
  37         if (mux->lock)
  38                 spin_lock_irqsave(mux->lock, flags);
  39         else
  40                 __acquire(mux->lock);
  41
  42         regmap_write(mux->regmap, mux->data->clr_ofs,
  43                      BIT(mux->data->gate_shift));
  44
  45         /*
  46          * If the parent has been changed when the clock was disabled, it will
  47          * not be effective yet. Set the update bit to ensure the mux gets
  48          * updated.
  49          */
  50         if (mux->reparent && mux->data->upd_shift >= 0) {
  51                 regmap_write(mux->regmap, mux->data->upd_ofs,
  52                              BIT(mux->data->upd_shift));
  53                 mux->reparent = false;
  54         }
  55
  56         if (mux->lock)
  57                 spin_unlock_irqrestore(mux->lock, flags);
  58         else
  59                 __release(mux->lock);
  60
  61         return 0;
  62 }
  63
  64 static void mtk_clk_mux_disable_setclr(struct clk_hw *hw)
  65 {
  66         struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
  67
  68         regmap_write(mux->regmap, mux->data->set_ofs,
  69                         BIT(mux->data->gate_shift));
  70 }
  71
  72 static int mtk_clk_mux_is_enabled(struct clk_hw *hw)
  73 {
  74         struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
  75         u32 val;
  76
  77         regmap_read(mux->regmap, mux->data->mux_ofs, &val);
  78
  79         return (val & BIT(mux->data->gate_shift)) == 0;
  80 }
  81
  82 static u8 mtk_clk_mux_get_parent(struct clk_hw *hw)
  83 {
  84         struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
  85         u32 mask = GENMASK(mux->data->mux_width - 1, 0);
  86         u32 val;
  87
  88         regmap_read(mux->regmap, mux->data->mux_ofs, &val);
  89         val = (val >> mux->data->mux_shift) & mask;
  90
  91         return val;
  92 }
  93
  94 static int mtk_clk_mux_set_parent_setclr_lock(struct clk_hw *hw, u8 index)
  95 {
  96         struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
  97         u32 mask = GENMASK(mux->data->mux_width - 1, 0);
  98         u32 val, orig;
  99         unsigned long flags = 0;
 100
 101         if (mux->lock)
 102                 spin_lock_irqsave(mux->lock, flags);
 103         else
 104                 __acquire(mux->lock);
 105
 106         regmap_read(mux->regmap, mux->data->mux_ofs, &orig);
 107         val = (orig & ~(mask << mux->data->mux_shift))
 108                         | (index << mux->data->mux_shift);
 109
 110         if (val != orig) {
 111                 regmap_write(mux->regmap, mux->data->clr_ofs,
 112                                 mask << mux->data->mux_shift);
 113                 regmap_write(mux->regmap, mux->data->set_ofs,
 114                                 index << mux->data->mux_shift);
 115
 116                 if (mux->data->upd_shift >= 0) {
 117                         regmap_write(mux->regmap, mux->data->upd_ofs,
 118                                         BIT(mux->data->upd_shift));
 119                         mux->reparent = true;
 120                 }
 121         }
 122
 123         if (mux->lock)
 124                 spin_unlock_irqrestore(mux->lock, flags);
 125         else
 126                 __release(mux->lock);
 127
 128         return 0;
 129 }
 130
 131 const struct clk_ops mtk_mux_clr_set_upd_ops = {
 132         .get_parent = mtk_clk_mux_get_parent,
 133         .set_parent = mtk_clk_mux_set_parent_setclr_lock,
 134 };
 135 EXPORT_SYMBOL_GPL(mtk_mux_clr_set_upd_ops);
 136
 137 const struct clk_ops mtk_mux_gate_clr_set_upd_ops  = {
 138         .enable = mtk_clk_mux_enable_setclr,
 139         .disable = mtk_clk_mux_disable_setclr,
 140         .is_enabled = mtk_clk_mux_is_enabled,
 141         .get_parent = mtk_clk_mux_get_parent,
 142         .set_parent = mtk_clk_mux_set_parent_setclr_lock,
 143 };
 144 EXPORT_SYMBOL_GPL(mtk_mux_gate_clr_set_upd_ops);
 145
 146 static struct clk *mtk_clk_register_mux(const struct mtk_mux *mux,
 147                                  struct regmap *regmap,
 148                                  spinlock_t *lock)
 149 {
 150         struct mtk_clk_mux *clk_mux;
 151         struct clk_init_data init = {};
 152         struct clk *clk;
 153
 154         clk_mux = kzalloc(sizeof(*clk_mux), GFP_KERNEL);
 155         if (!clk_mux)
 156                 return ERR_PTR(-ENOMEM);
 157
 158         init.name = mux->name;
 159         init.flags = mux->flags | CLK_SET_RATE_PARENT;
 160         init.parent_names = mux->parent_names;
 161         init.num_parents = mux->num_parents;
 162         init.ops = mux->ops;
 163
 164         clk_mux->regmap = regmap;
 165         clk_mux->data = mux;
 166         clk_mux->lock = lock;
 167         clk_mux->hw.init = &init;
 168
 169         clk = clk_register(NULL, &clk_mux->hw);
 170         if (IS_ERR(clk)) {
 171                 kfree(clk_mux);
 172                 return clk;
 173         }
 174
 175         return clk;
 176 }
 177
 178 static void mtk_clk_unregister_mux(struct clk *clk)
 179 {
 180         struct mtk_clk_mux *mux;
 181         struct clk_hw *hw;
 182
 183         hw = __clk_get_hw(clk);
 184         if (!hw)
 185                 return;
 186
 187         mux = to_mtk_clk_mux(hw);
 188
 189         clk_unregister(clk);
 190         kfree(mux);
 191 }
 192
 193 int mtk_clk_register_muxes(const struct mtk_mux *muxes,
 194                            int num, struct device_node *node,
 195                            spinlock_t *lock,
 196                            struct clk_onecell_data *clk_data)
 197 {
 198         struct regmap *regmap;
 199         struct clk *clk;
 200         int i;
 201
 202         regmap = device_node_to_regmap(node);
 203         if (IS_ERR(regmap)) {
 204                 pr_err("Cannot find regmap for %pOF: %pe\n", node, regmap);
 205                 return PTR_ERR(regmap);
 206         }
 207
 208         for (i = 0; i < num; i++) {
 209                 const struct mtk_mux *mux = &muxes[i];
 210
 211                 if (!IS_ERR_OR_NULL(clk_data->clks[mux->id])) {
 212                         pr_warn("%pOF: Trying to register duplicate clock ID: %d\n",
 213                                 node, mux->id);
 214                         continue;
 215                 }
 216
 217                 clk = mtk_clk_register_mux(mux, regmap, lock);
 218
 219                 if (IS_ERR(clk)) {
 220                         pr_err("Failed to register clk %s: %pe\n", mux->name, clk);
 221                         goto err;
 222                 }
 223
 224                 clk_data->clks[mux->id] = clk;
 225         }
 226
 227         return 0;
 228
 229 err:
 230         while (--i >= 0) {
 231                 const struct mtk_mux *mux = &muxes[i];
 232
 233                 if (IS_ERR_OR_NULL(clk_data->clks[mux->id]))
 234                         continue;
 235
 236                 mtk_clk_unregister_mux(clk_data->clks[mux->id]);
 237                 clk_data->clks[mux->id] = ERR_PTR(-ENOENT);
 238         }
 239
 240         return PTR_ERR(clk);
 241 }
 242 EXPORT_SYMBOL_GPL(mtk_clk_register_muxes);
 243
 244 void mtk_clk_unregister_muxes(const struct mtk_mux *muxes, int num,
 245                               struct clk_onecell_data *clk_data)
 246 {
 247         int i;
 248
 249         if (!clk_data)
 250                 return;
 251
 252         for (i = num; i > 0; i--) {
 253                 const struct mtk_mux *mux = &muxes[i - 1];
 254
 255                 if (IS_ERR_OR_NULL(clk_data->clks[mux->id]))
 256                         continue;
 257
 258                 mtk_clk_unregister_mux(clk_data->clks[mux->id]);
 259                 clk_data->clks[mux->id] = ERR_PTR(-ENOENT);
 260         }
 261 }
 262 EXPORT_SYMBOL_GPL(mtk_clk_unregister_muxes);
 263
 264 MODULE_LICENSE("GPL");