128 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*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 clock16 * @divider: the parent class17 * @ops: pointer to clk_ops of parent class18 * @fixup: a hook to fixup the write value19 *20 * The imx fixup divider clock is a subclass of basic clk_divider21 * 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