207 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * mmp factor clock operation source file4 *5 * Copyright (C) 2012 Marvell6 * Chao Xie <xiechao.mail@gmail.com>7 */8 9#include <linux/clk-provider.h>10#include <linux/slab.h>11#include <linux/io.h>12#include <linux/err.h>13 14#include "clk.h"15/*16 * It is M/N clock17 *18 * Fout from synthesizer can be given from two equations:19 * numerator/denominator = Fin / (Fout * factor)20 */21 22#define to_clk_factor(hw) container_of(hw, struct mmp_clk_factor, hw)23 24static long clk_factor_round_rate(struct clk_hw *hw, unsigned long drate,25 unsigned long *prate)26{27 struct mmp_clk_factor *factor = to_clk_factor(hw);28 u64 rate = 0, prev_rate;29 int i;30 31 for (i = 0; i < factor->ftbl_cnt; i++) {32 prev_rate = rate;33 rate = *prate;34 rate *= factor->ftbl[i].den;35 do_div(rate, factor->ftbl[i].num * factor->masks->factor);36 37 if (rate > drate)38 break;39 }40 if ((i == 0) || (i == factor->ftbl_cnt)) {41 return rate;42 } else {43 if ((drate - prev_rate) > (rate - drate))44 return rate;45 else46 return prev_rate;47 }48}49 50static unsigned long clk_factor_recalc_rate(struct clk_hw *hw,51 unsigned long parent_rate)52{53 struct mmp_clk_factor *factor = to_clk_factor(hw);54 struct mmp_clk_factor_masks *masks = factor->masks;55 unsigned int val, num, den;56 u64 rate;57 58 val = readl_relaxed(factor->base);59 60 /* calculate numerator */61 num = (val >> masks->num_shift) & masks->num_mask;62 63 /* calculate denominator */64 den = (val >> masks->den_shift) & masks->den_mask;65 66 if (!den)67 return 0;68 69 rate = parent_rate;70 rate *= den;71 do_div(rate, num * factor->masks->factor);72 73 return rate;74}75 76/* Configures new clock rate*/77static int clk_factor_set_rate(struct clk_hw *hw, unsigned long drate,78 unsigned long prate)79{80 struct mmp_clk_factor *factor = to_clk_factor(hw);81 struct mmp_clk_factor_masks *masks = factor->masks;82 int i;83 unsigned long val;84 unsigned long flags = 0;85 u64 rate = 0;86 87 for (i = 0; i < factor->ftbl_cnt; i++) {88 rate = prate;89 rate *= factor->ftbl[i].den;90 do_div(rate, factor->ftbl[i].num * factor->masks->factor);91 92 if (rate > drate)93 break;94 }95 if (i > 0)96 i--;97 98 if (factor->lock)99 spin_lock_irqsave(factor->lock, flags);100 101 val = readl_relaxed(factor->base);102 103 val &= ~(masks->num_mask << masks->num_shift);104 val |= (factor->ftbl[i].num & masks->num_mask) << masks->num_shift;105 106 val &= ~(masks->den_mask << masks->den_shift);107 val |= (factor->ftbl[i].den & masks->den_mask) << masks->den_shift;108 109 writel_relaxed(val, factor->base);110 111 if (factor->lock)112 spin_unlock_irqrestore(factor->lock, flags);113 114 return 0;115}116 117static int clk_factor_init(struct clk_hw *hw)118{119 struct mmp_clk_factor *factor = to_clk_factor(hw);120 struct mmp_clk_factor_masks *masks = factor->masks;121 u32 val, num, den;122 int i;123 unsigned long flags = 0;124 125 if (factor->lock)126 spin_lock_irqsave(factor->lock, flags);127 128 val = readl(factor->base);129 130 /* calculate numerator */131 num = (val >> masks->num_shift) & masks->num_mask;132 133 /* calculate denominator */134 den = (val >> masks->den_shift) & masks->den_mask;135 136 for (i = 0; i < factor->ftbl_cnt; i++)137 if (den == factor->ftbl[i].den && num == factor->ftbl[i].num)138 break;139 140 if (i >= factor->ftbl_cnt) {141 val &= ~(masks->num_mask << masks->num_shift);142 val |= (factor->ftbl[0].num & masks->num_mask) <<143 masks->num_shift;144 145 val &= ~(masks->den_mask << masks->den_shift);146 val |= (factor->ftbl[0].den & masks->den_mask) <<147 masks->den_shift;148 }149 150 if (!(val & masks->enable_mask) || i >= factor->ftbl_cnt) {151 val |= masks->enable_mask;152 writel(val, factor->base);153 }154 155 if (factor->lock)156 spin_unlock_irqrestore(factor->lock, flags);157 158 return 0;159}160 161static const struct clk_ops clk_factor_ops = {162 .recalc_rate = clk_factor_recalc_rate,163 .round_rate = clk_factor_round_rate,164 .set_rate = clk_factor_set_rate,165 .init = clk_factor_init,166};167 168struct clk *mmp_clk_register_factor(const char *name, const char *parent_name,169 unsigned long flags, void __iomem *base,170 struct mmp_clk_factor_masks *masks,171 struct mmp_clk_factor_tbl *ftbl,172 unsigned int ftbl_cnt, spinlock_t *lock)173{174 struct mmp_clk_factor *factor;175 struct clk_init_data init;176 struct clk *clk;177 178 if (!masks) {179 pr_err("%s: must pass a clk_factor_mask\n", __func__);180 return ERR_PTR(-EINVAL);181 }182 183 factor = kzalloc(sizeof(*factor), GFP_KERNEL);184 if (!factor)185 return ERR_PTR(-ENOMEM);186 187 /* struct clk_aux assignments */188 factor->base = base;189 factor->masks = masks;190 factor->ftbl = ftbl;191 factor->ftbl_cnt = ftbl_cnt;192 factor->hw.init = &init;193 factor->lock = lock;194 195 init.name = name;196 init.ops = &clk_factor_ops;197 init.flags = flags;198 init.parent_names = &parent_name;199 init.num_parents = 1;200 201 clk = clk_register(NULL, &factor->hw);202 if (IS_ERR_OR_NULL(clk))203 kfree(factor);204 205 return clk;206}207