LXR linux/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 */
  27struct clk_fixup_mux {
  28        struct clk_mux mux;
  29        const struct clk_ops *ops;
  30        void (*fixup)(u32 *val);
  31};
  32
  33static 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
  40static 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
  47static 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
  67static 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
  72struct 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}
 107