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

   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  */
  23 struct clk_fixup_div {
  24         struct clk_divider divider;
  25         const struct clk_ops *ops;
  26         void (*fixup)(u32 *val);
  27 };
  28
  29 static 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
  36 static 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
  44 static 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
  52 static 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
  82 static 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
  88 struct 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 }