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