cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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clk-fixup-div.c (3101B)

      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}