drivers/clk/imx/clk-busy.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2012 Freescale Semiconductor, Inc.
   4  * Copyright 2012 Linaro Ltd.
   5  */
   6
   7 #include <linux/bits.h>
   8 #include <linux/clk.h>
   9 #include <linux/clk-provider.h>
  10 #include <linux/io.h>
  11 #include <linux/slab.h>
  12 #include <linux/jiffies.h>
  13 #include <linux/err.h>
  14 #include "clk.h"
  15
  16 static int clk_busy_wait(void __iomem *reg, u8 shift)
  17 {
  18         unsigned long timeout = jiffies + msecs_to_jiffies(10);
  19
  20         while (readl_relaxed(reg) & (1 << shift))
  21                 if (time_after(jiffies, timeout))
  22                         return -ETIMEDOUT;
  23
  24         return 0;
  25 }
  26
  27 struct clk_busy_divider {
  28         struct clk_divider div;
  29         const struct clk_ops *div_ops;
  30         void __iomem *reg;
  31         u8 shift;
  32 };
  33
  34 static inline struct clk_busy_divider *to_clk_busy_divider(struct clk_hw *hw)
  35 {
  36         struct clk_divider *div = to_clk_divider(hw);
  37
  38         return container_of(div, struct clk_busy_divider, div);
  39 }
  40
  41 static unsigned long clk_busy_divider_recalc_rate(struct clk_hw *hw,
  42                                                   unsigned long parent_rate)
  43 {
  44         struct clk_busy_divider *busy = to_clk_busy_divider(hw);
  45
  46         return busy->div_ops->recalc_rate(&busy->div.hw, parent_rate);
  47 }
  48
  49 static long clk_busy_divider_round_rate(struct clk_hw *hw, unsigned long rate,
  50                                         unsigned long *prate)
  51 {
  52         struct clk_busy_divider *busy = to_clk_busy_divider(hw);
  53
  54         return busy->div_ops->round_rate(&busy->div.hw, rate, prate);
  55 }
  56
  57 static int clk_busy_divider_set_rate(struct clk_hw *hw, unsigned long rate,
  58                 unsigned long parent_rate)
  59 {
  60         struct clk_busy_divider *busy = to_clk_busy_divider(hw);
  61         int ret;
  62
  63         ret = busy->div_ops->set_rate(&busy->div.hw, rate, parent_rate);
  64         if (!ret)
  65                 ret = clk_busy_wait(busy->reg, busy->shift);
  66
  67         return ret;
  68 }
  69
  70 static const struct clk_ops clk_busy_divider_ops = {
  71         .recalc_rate = clk_busy_divider_recalc_rate,
  72         .round_rate = clk_busy_divider_round_rate,
  73         .set_rate = clk_busy_divider_set_rate,
  74 };
  75
  76 struct clk_hw *imx_clk_hw_busy_divider(const char *name, const char *parent_name,
  77                                  void __iomem *reg, u8 shift, u8 width,
  78                                  void __iomem *busy_reg, u8 busy_shift)
  79 {
  80         struct clk_busy_divider *busy;
  81         struct clk_hw *hw;
  82         struct clk_init_data init;
  83         int ret;
  84
  85         busy = kzalloc(sizeof(*busy), GFP_KERNEL);
  86         if (!busy)
  87                 return ERR_PTR(-ENOMEM);
  88
  89         busy->reg = busy_reg;
  90         busy->shift = busy_shift;
  91
  92         busy->div.reg = reg;
  93         busy->div.shift = shift;
  94         busy->div.width = width;
  95         busy->div.lock = &imx_ccm_lock;
  96         busy->div_ops = &clk_divider_ops;
  97
  98         init.name = name;
  99         init.ops = &clk_busy_divider_ops;
 100         init.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL;
 101         init.parent_names = &parent_name;
 102         init.num_parents = 1;
 103
 104         busy->div.hw.init = &init;
 105
 106         hw = &busy->div.hw;
 107
 108         ret = clk_hw_register(NULL, hw);
 109         if (ret) {
 110                 kfree(busy);
 111                 return ERR_PTR(ret);
 112         }
 113
 114         return hw;
 115 }
 116
 117 struct clk_busy_mux {
 118         struct clk_mux mux;
 119         const struct clk_ops *mux_ops;
 120         void __iomem *reg;
 121         u8 shift;
 122 };
 123
 124 static inline struct clk_busy_mux *to_clk_busy_mux(struct clk_hw *hw)
 125 {
 126         struct clk_mux *mux = to_clk_mux(hw);
 127
 128         return container_of(mux, struct clk_busy_mux, mux);
 129 }
 130
 131 static u8 clk_busy_mux_get_parent(struct clk_hw *hw)
 132 {
 133         struct clk_busy_mux *busy = to_clk_busy_mux(hw);
 134
 135         return busy->mux_ops->get_parent(&busy->mux.hw);
 136 }
 137
 138 static int clk_busy_mux_set_parent(struct clk_hw *hw, u8 index)
 139 {
 140         struct clk_busy_mux *busy = to_clk_busy_mux(hw);
 141         int ret;
 142
 143         ret = busy->mux_ops->set_parent(&busy->mux.hw, index);
 144         if (!ret)
 145                 ret = clk_busy_wait(busy->reg, busy->shift);
 146
 147         return ret;
 148 }
 149
 150 static const struct clk_ops clk_busy_mux_ops = {
 151         .get_parent = clk_busy_mux_get_parent,
 152         .set_parent = clk_busy_mux_set_parent,
 153 };
 154
 155 struct clk_hw *imx_clk_hw_busy_mux(const char *name, void __iomem *reg, u8 shift,
 156                              u8 width, void __iomem *busy_reg, u8 busy_shift,
 157                              const char * const *parent_names, int num_parents)
 158 {
 159         struct clk_busy_mux *busy;
 160         struct clk_hw *hw;
 161         struct clk_init_data init;
 162         int ret;
 163
 164         busy = kzalloc(sizeof(*busy), GFP_KERNEL);
 165         if (!busy)
 166                 return ERR_PTR(-ENOMEM);
 167
 168         busy->reg = busy_reg;
 169         busy->shift = busy_shift;
 170
 171         busy->mux.reg = reg;
 172         busy->mux.shift = shift;
 173         busy->mux.mask = BIT(width) - 1;
 174         busy->mux.lock = &imx_ccm_lock;
 175         busy->mux_ops = &clk_mux_ops;
 176
 177         init.name = name;
 178         init.ops = &clk_busy_mux_ops;
 179         init.flags = CLK_IS_CRITICAL;
 180         init.parent_names = parent_names;
 181         init.num_parents = num_parents;
 182
 183         busy->mux.hw.init = &init;
 184
 185         hw = &busy->mux.hw;
 186
 187         ret = clk_hw_register(NULL, hw);
 188         if (ret) {
 189                 kfree(busy);
 190                 return ERR_PTR(ret);
 191         }
 192
 193         return hw;
 194 }