drivers/clk/imx/clk-busy.c

   1 /*
   2  * Copyright 2012 Freescale Semiconductor, Inc.
   3  * Copyright 2012 Linaro Ltd.
   4  *
   5  * The code contained herein is licensed under the GNU General Public
   6  * License. You may obtain a copy of the GNU General Public License
   7  * Version 2 or later at the following locations:
   8  *
   9  * http://www.opensource.org/licenses/gpl-license.html
  10  * http://www.gnu.org/copyleft/gpl.html
  11  */
  12
  13 #include <linux/clk.h>
  14 #include <linux/clk-provider.h>
  15 #include <linux/io.h>
  16 #include <linux/slab.h>
  17 #include <linux/jiffies.h>
  18 #include <linux/err.h>
  19 #include "clk.h"
  20
  21 static int clk_busy_wait(void __iomem *reg, u8 shift)
  22 {
  23         unsigned long timeout = jiffies + msecs_to_jiffies(10);
  24
  25         while (readl_relaxed(reg) & (1 << shift))
  26                 if (time_after(jiffies, timeout))
  27                         return -ETIMEDOUT;
  28
  29         return 0;
  30 }
  31
  32 struct clk_busy_divider {
  33         struct clk_divider div;
  34         const struct clk_ops *div_ops;
  35         void __iomem *reg;
  36         u8 shift;
  37 };
  38
  39 static inline struct clk_busy_divider *to_clk_busy_divider(struct clk_hw *hw)
  40 {
  41         struct clk_divider *div = to_clk_divider(hw);
  42
  43         return container_of(div, struct clk_busy_divider, div);
  44 }
  45
  46 static unsigned long clk_busy_divider_recalc_rate(struct clk_hw *hw,
  47                                                   unsigned long parent_rate)
  48 {
  49         struct clk_busy_divider *busy = to_clk_busy_divider(hw);
  50
  51         return busy->div_ops->recalc_rate(&busy->div.hw, parent_rate);
  52 }
  53
  54 static long clk_busy_divider_round_rate(struct clk_hw *hw, unsigned long rate,
  55                                         unsigned long *prate)
  56 {
  57         struct clk_busy_divider *busy = to_clk_busy_divider(hw);
  58
  59         return busy->div_ops->round_rate(&busy->div.hw, rate, prate);
  60 }
  61
  62 static int clk_busy_divider_set_rate(struct clk_hw *hw, unsigned long rate,
  63                 unsigned long parent_rate)
  64 {
  65         struct clk_busy_divider *busy = to_clk_busy_divider(hw);
  66         int ret;
  67
  68         ret = busy->div_ops->set_rate(&busy->div.hw, rate, parent_rate);
  69         if (!ret)
  70                 ret = clk_busy_wait(busy->reg, busy->shift);
  71
  72         return ret;
  73 }
  74
  75 static const struct clk_ops clk_busy_divider_ops = {
  76         .recalc_rate = clk_busy_divider_recalc_rate,
  77         .round_rate = clk_busy_divider_round_rate,
  78         .set_rate = clk_busy_divider_set_rate,
  79 };
  80
  81 struct clk *imx_clk_busy_divider(const char *name, const char *parent_name,
  82                                  void __iomem *reg, u8 shift, u8 width,
  83                                  void __iomem *busy_reg, u8 busy_shift)
  84 {
  85         struct clk_busy_divider *busy;
  86         struct clk *clk;
  87         struct clk_init_data init;
  88
  89         busy = kzalloc(sizeof(*busy), GFP_KERNEL);
  90         if (!busy)
  91                 return ERR_PTR(-ENOMEM);
  92
  93         busy->reg = busy_reg;
  94         busy->shift = busy_shift;
  95
  96         busy->div.reg = reg;
  97         busy->div.shift = shift;
  98         busy->div.width = width;
  99         busy->div.lock = &imx_ccm_lock;
 100         busy->div_ops = &clk_divider_ops;
 101
 102         init.name = name;
 103         init.ops = &clk_busy_divider_ops;
 104         init.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL;
 105         init.parent_names = &parent_name;
 106         init.num_parents = 1;
 107
 108         busy->div.hw.init = &init;
 109
 110         clk = clk_register(NULL, &busy->div.hw);
 111         if (IS_ERR(clk))
 112                 kfree(busy);
 113
 114         return clk;
 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 *imx_clk_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 *clk;
 161         struct clk_init_data init;
 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         clk = clk_register(NULL, &busy->mux.hw);
 185         if (IS_ERR(clk))
 186                 kfree(busy);
 187
 188         return clk;
 189 }