drivers/clk/imx/clk-fixup-mux.c

   1 /*
   2  * Copyright (C) 2013 Freescale Semiconductor, Inc.
   3  *
   4  * The code contained herein is licensed under the GNU General Public
   5  * License. You may obtain a copy of the GNU General Public License
   6  * Version 2 or later at the following locations:
   7  *
   8  * http://www.opensource.org/licenses/gpl-license.html
   9  * http://www.gnu.org/copyleft/gpl.html
  10  */
  11
  12 #include <linux/clk-provider.h>
  13 #include <linux/err.h>
  14 #include <linux/io.h>
  15 #include <linux/slab.h>
  16 #include "clk.h"
  17
  18 /**
  19  * struct clk_fixup_mux - imx integer fixup multiplexer clock
  20  * @mux: the parent class
  21  * @ops: pointer to clk_ops of parent class
  22  * @fixup: a hook to fixup the write value
  23  *
  24  * The imx fixup multiplexer clock is a subclass of basic clk_mux
  25  * with an addtional fixup hook.
  26  */
  27 struct clk_fixup_mux {
  28         struct clk_mux mux;
  29         const struct clk_ops *ops;
  30         void (*fixup)(u32 *val);
  31 };
  32
  33 static inline struct clk_fixup_mux *to_clk_fixup_mux(struct clk_hw *hw)
  34 {
  35         struct clk_mux *mux = to_clk_mux(hw);
  36
  37         return container_of(mux, struct clk_fixup_mux, mux);
  38 }
  39
  40 static u8 clk_fixup_mux_get_parent(struct clk_hw *hw)
  41 {
  42         struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
  43
  44         return fixup_mux->ops->get_parent(&fixup_mux->mux.hw);
  45 }
  46
  47 static int clk_fixup_mux_set_parent(struct clk_hw *hw, u8 index)
  48 {
  49         struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
  50         struct clk_mux *mux = to_clk_mux(hw);
  51         unsigned long flags = 0;
  52         u32 val;
  53
  54         spin_lock_irqsave(mux->lock, flags);
  55
  56         val = readl(mux->reg);
  57         val &= ~(mux->mask << mux->shift);
  58         val |= index << mux->shift;
  59         fixup_mux->fixup(&val);
  60         writel(val, mux->reg);
  61
  62         spin_unlock_irqrestore(mux->lock, flags);
  63
  64         return 0;
  65 }
  66
  67 static const struct clk_ops clk_fixup_mux_ops = {
  68         .get_parent = clk_fixup_mux_get_parent,
  69         .set_parent = clk_fixup_mux_set_parent,
  70 };
  71
  72 struct clk *imx_clk_fixup_mux(const char *name, void __iomem *reg,
  73                               u8 shift, u8 width, const char **parents,
  74                               int num_parents, void (*fixup)(u32 *val))
  75 {
  76         struct clk_fixup_mux *fixup_mux;
  77         struct clk *clk;
  78         struct clk_init_data init;
  79
  80         if (!fixup)
  81                 return ERR_PTR(-EINVAL);
  82
  83         fixup_mux = kzalloc(sizeof(*fixup_mux), GFP_KERNEL);
  84         if (!fixup_mux)
  85                 return ERR_PTR(-ENOMEM);
  86
  87         init.name = name;
  88         init.ops = &clk_fixup_mux_ops;
  89         init.parent_names = parents;
  90         init.num_parents = num_parents;
  91         init.flags = 0;
  92
  93         fixup_mux->mux.reg = reg;
  94         fixup_mux->mux.shift = shift;
  95         fixup_mux->mux.mask = BIT(width) - 1;
  96         fixup_mux->mux.lock = &imx_ccm_lock;
  97         fixup_mux->mux.hw.init = &init;
  98         fixup_mux->ops = &clk_mux_ops;
  99         fixup_mux->fixup = fixup;
 100
 101         clk = clk_register(NULL, &fixup_mux->mux.hw);
 102         if (IS_ERR(clk))
 103                 kfree(fixup_mux);
 104
 105         return clk;
 106 }