arch/arm/mach-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 #define to_clk_mux(_hw) container_of(_hw, struct clk_mux, hw)
  19
  20 /**
  21  * struct clk_fixup_mux - imx integer fixup multiplexer clock
  22  * @mux: the parent class
  23  * @ops: pointer to clk_ops of parent class
  24  * @fixup: a hook to fixup the write value
  25  *
  26  * The imx fixup multiplexer clock is a subclass of basic clk_mux
  27  * with an addtional fixup hook.
  28  */
  29 struct clk_fixup_mux {
  30         struct clk_mux mux;
  31         const struct clk_ops *ops;
  32         void (*fixup)(u32 *val);
  33 };
  34
  35 static inline struct clk_fixup_mux *to_clk_fixup_mux(struct clk_hw *hw)
  36 {
  37         struct clk_mux *mux = to_clk_mux(hw);
  38
  39         return container_of(mux, struct clk_fixup_mux, mux);
  40 }
  41
  42 static u8 clk_fixup_mux_get_parent(struct clk_hw *hw)
  43 {
  44         struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
  45
  46         return fixup_mux->ops->get_parent(&fixup_mux->mux.hw);
  47 }
  48
  49 static int clk_fixup_mux_set_parent(struct clk_hw *hw, u8 index)
  50 {
  51         struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
  52         struct clk_mux *mux = to_clk_mux(hw);
  53         unsigned long flags = 0;
  54         u32 val;
  55
  56         spin_lock_irqsave(mux->lock, flags);
  57
  58         val = readl(mux->reg);
  59         val &= ~(mux->mask << mux->shift);
  60         val |= index << mux->shift;
  61         fixup_mux->fixup(&val);
  62         writel(val, mux->reg);
  63
  64         spin_unlock_irqrestore(mux->lock, flags);
  65
  66         return 0;
  67 }
  68
  69 static const struct clk_ops clk_fixup_mux_ops = {
  70         .get_parent = clk_fixup_mux_get_parent,
  71         .set_parent = clk_fixup_mux_set_parent,
  72 };
  73
  74 struct clk *imx_clk_fixup_mux(const char *name, void __iomem *reg,
  75                               u8 shift, u8 width, const char **parents,
  76                               int num_parents, void (*fixup)(u32 *val))
  77 {
  78         struct clk_fixup_mux *fixup_mux;
  79         struct clk *clk;
  80         struct clk_init_data init;
  81
  82         if (!fixup)
  83                 return ERR_PTR(-EINVAL);
  84
  85         fixup_mux = kzalloc(sizeof(*fixup_mux), GFP_KERNEL);
  86         if (!fixup_mux)
  87                 return ERR_PTR(-ENOMEM);
  88
  89         init.name = name;
  90         init.ops = &clk_fixup_mux_ops;
  91         init.parent_names = parents;
  92         init.num_parents = num_parents;
  93         init.flags = 0;
  94
  95         fixup_mux->mux.reg = reg;
  96         fixup_mux->mux.shift = shift;
  97         fixup_mux->mux.mask = BIT(width) - 1;
  98         fixup_mux->mux.lock = &imx_ccm_lock;
  99         fixup_mux->mux.hw.init = &init;
 100         fixup_mux->ops = &clk_mux_ops;
 101         fixup_mux->fixup = fixup;
 102
 103         clk = clk_register(NULL, &fixup_mux->mux.hw);
 104         if (IS_ERR(clk))
 105                 kfree(fixup_mux);
 106
 107         return clk;
 108 }