linux/drivers/clk/imx/clk-fixup-div.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (C) 2013 Freescale Semiconductor, Inc.
   4 */
   5
   6#include <linux/clk-provider.h>
   7#include <linux/err.h>
   8#include <linux/io.h>
   9#include <linux/slab.h>
  10#include "clk.h"
  11
  12#define div_mask(d)     ((1 << (d->width)) - 1)
  13
  14/**
  15 * struct clk_fixup_div - imx integer fixup divider clock
  16 * @divider: the parent class
  17 * @ops: pointer to clk_ops of parent class
  18 * @fixup: a hook to fixup the write value
  19 *
  20 * The imx fixup divider clock is a subclass of basic clk_divider
  21 * with an addtional fixup hook.
  22 */
  23struct clk_fixup_div {
  24        struct clk_divider divider;
  25        const struct clk_ops *ops;
  26        void (*fixup)(u32 *val);
  27};
  28
  29static inline struct clk_fixup_div *to_clk_fixup_div(struct clk_hw *hw)
  30{
  31        struct clk_divider *divider = to_clk_divider(hw);
  32
  33        return container_of(divider, struct clk_fixup_div, divider);
  34}
  35
  36static unsigned long clk_fixup_div_recalc_rate(struct clk_hw *hw,
  37                                         unsigned long parent_rate)
  38{
  39        struct clk_fixup_div *fixup_div = to_clk_fixup_div(hw);
  40
  41        return fixup_div->ops->recalc_rate(&fixup_div->divider.hw, parent_rate);
  42}
  43
  44static long clk_fixup_div_round_rate(struct clk_hw *hw, unsigned long rate,
  45                               unsigned long *prate)
  46{
  47        struct clk_fixup_div *fixup_div = to_clk_fixup_div(hw);
  48
  49        return fixup_div->ops->round_rate(&fixup_div->divider.hw, rate, prate);
  50}
  51
  52static int clk_fixup_div_set_rate(struct clk_hw *hw, unsigned long rate,
  53                            unsigned long parent_rate)
  54{
  55        struct clk_fixup_div *fixup_div = to_clk_fixup_div(hw);
  56        struct clk_divider *div = to_clk_divider(hw);
  57        unsigned int divider, value;
  58        unsigned long flags;
  59        u32 val;
  60
  61        divider = parent_rate / rate;
  62
  63        /* Zero based divider */
  64        value = divider - 1;
  65
  66        if (value > div_mask(div))
  67                value = div_mask(div);
  68
  69        spin_lock_irqsave(div->lock, flags);
  70
  71        val = readl(div->reg);
  72        val &= ~(div_mask(div) << div->shift);
  73        val |= value << div->shift;
  74        fixup_div->fixup(&val);
  75        writel(val, div->reg);
  76
  77        spin_unlock_irqrestore(div->lock, flags);
  78
  79        return 0;
  80}
  81
  82static const struct clk_ops clk_fixup_div_ops = {
  83        .recalc_rate = clk_fixup_div_recalc_rate,
  84        .round_rate = clk_fixup_div_round_rate,
  85        .set_rate = clk_fixup_div_set_rate,
  86};
  87
  88struct clk_hw *imx_clk_hw_fixup_divider(const char *name, const char *parent,
  89                                  void __iomem *reg, u8 shift, u8 width,
  90                                  void (*fixup)(u32 *val))
  91{
  92        struct clk_fixup_div *fixup_div;
  93        struct clk_hw *hw;
  94        struct clk_init_data init;
  95        int ret;
  96
  97        if (!fixup)
  98                return ERR_PTR(-EINVAL);
  99
 100        fixup_div = kzalloc(sizeof(*fixup_div), GFP_KERNEL);
 101        if (!fixup_div)
 102                return ERR_PTR(-ENOMEM);
 103
 104        init.name = name;
 105        init.ops = &clk_fixup_div_ops;
 106        init.flags = CLK_SET_RATE_PARENT;
 107        init.parent_names = parent ? &parent : NULL;
 108        init.num_parents = parent ? 1 : 0;
 109
 110        fixup_div->divider.reg = reg;
 111        fixup_div->divider.shift = shift;
 112        fixup_div->divider.width = width;
 113        fixup_div->divider.lock = &imx_ccm_lock;
 114        fixup_div->divider.hw.init = &init;
 115        fixup_div->ops = &clk_divider_ops;
 116        fixup_div->fixup = fixup;
 117
 118        hw = &fixup_div->divider.hw;
 119
 120        ret = clk_hw_register(NULL, hw);
 121        if (ret) {
 122                kfree(fixup_div);
 123                return ERR_PTR(ret);
 124        }
 125
 126        return hw;
 127}
 128