ccu_nk.c (3659B)
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * Copyright (C) 2016 Maxime Ripard 4 * Maxime Ripard <maxime.ripard@free-electrons.com> 5 */ 6 7#include <linux/clk-provider.h> 8#include <linux/io.h> 9 10#include "ccu_gate.h" 11#include "ccu_nk.h" 12 13struct _ccu_nk { 14 unsigned long n, min_n, max_n; 15 unsigned long k, min_k, max_k; 16}; 17 18static void ccu_nk_find_best(unsigned long parent, unsigned long rate, 19 struct _ccu_nk *nk) 20{ 21 unsigned long best_rate = 0; 22 unsigned int best_k = 0, best_n = 0; 23 unsigned int _k, _n; 24 25 for (_k = nk->min_k; _k <= nk->max_k; _k++) { 26 for (_n = nk->min_n; _n <= nk->max_n; _n++) { 27 unsigned long tmp_rate = parent * _n * _k; 28 29 if (tmp_rate > rate) 30 continue; 31 32 if ((rate - tmp_rate) < (rate - best_rate)) { 33 best_rate = tmp_rate; 34 best_k = _k; 35 best_n = _n; 36 } 37 } 38 } 39 40 nk->k = best_k; 41 nk->n = best_n; 42} 43 44static void ccu_nk_disable(struct clk_hw *hw) 45{ 46 struct ccu_nk *nk = hw_to_ccu_nk(hw); 47 48 return ccu_gate_helper_disable(&nk->common, nk->enable); 49} 50 51static int ccu_nk_enable(struct clk_hw *hw) 52{ 53 struct ccu_nk *nk = hw_to_ccu_nk(hw); 54 55 return ccu_gate_helper_enable(&nk->common, nk->enable); 56} 57 58static int ccu_nk_is_enabled(struct clk_hw *hw) 59{ 60 struct ccu_nk *nk = hw_to_ccu_nk(hw); 61 62 return ccu_gate_helper_is_enabled(&nk->common, nk->enable); 63} 64 65static unsigned long ccu_nk_recalc_rate(struct clk_hw *hw, 66 unsigned long parent_rate) 67{ 68 struct ccu_nk *nk = hw_to_ccu_nk(hw); 69 unsigned long rate, n, k; 70 u32 reg; 71 72 reg = readl(nk->common.base + nk->common.reg); 73 74 n = reg >> nk->n.shift; 75 n &= (1 << nk->n.width) - 1; 76 n += nk->n.offset; 77 if (!n) 78 n++; 79 80 k = reg >> nk->k.shift; 81 k &= (1 << nk->k.width) - 1; 82 k += nk->k.offset; 83 if (!k) 84 k++; 85 86 rate = parent_rate * n * k; 87 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) 88 rate /= nk->fixed_post_div; 89 90 return rate; 91} 92 93static long ccu_nk_round_rate(struct clk_hw *hw, unsigned long rate, 94 unsigned long *parent_rate) 95{ 96 struct ccu_nk *nk = hw_to_ccu_nk(hw); 97 struct _ccu_nk _nk; 98 99 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) 100 rate *= nk->fixed_post_div; 101 102 _nk.min_n = nk->n.min ?: 1; 103 _nk.max_n = nk->n.max ?: 1 << nk->n.width; 104 _nk.min_k = nk->k.min ?: 1; 105 _nk.max_k = nk->k.max ?: 1 << nk->k.width; 106 107 ccu_nk_find_best(*parent_rate, rate, &_nk); 108 rate = *parent_rate * _nk.n * _nk.k; 109 110 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) 111 rate = rate / nk->fixed_post_div; 112 113 return rate; 114} 115 116static int ccu_nk_set_rate(struct clk_hw *hw, unsigned long rate, 117 unsigned long parent_rate) 118{ 119 struct ccu_nk *nk = hw_to_ccu_nk(hw); 120 unsigned long flags; 121 struct _ccu_nk _nk; 122 u32 reg; 123 124 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) 125 rate = rate * nk->fixed_post_div; 126 127 _nk.min_n = nk->n.min ?: 1; 128 _nk.max_n = nk->n.max ?: 1 << nk->n.width; 129 _nk.min_k = nk->k.min ?: 1; 130 _nk.max_k = nk->k.max ?: 1 << nk->k.width; 131 132 ccu_nk_find_best(parent_rate, rate, &_nk); 133 134 spin_lock_irqsave(nk->common.lock, flags); 135 136 reg = readl(nk->common.base + nk->common.reg); 137 reg &= ~GENMASK(nk->n.width + nk->n.shift - 1, nk->n.shift); 138 reg &= ~GENMASK(nk->k.width + nk->k.shift - 1, nk->k.shift); 139 140 reg |= (_nk.k - nk->k.offset) << nk->k.shift; 141 reg |= (_nk.n - nk->n.offset) << nk->n.shift; 142 writel(reg, nk->common.base + nk->common.reg); 143 144 spin_unlock_irqrestore(nk->common.lock, flags); 145 146 ccu_helper_wait_for_lock(&nk->common, nk->lock); 147 148 return 0; 149} 150 151const struct clk_ops ccu_nk_ops = { 152 .disable = ccu_nk_disable, 153 .enable = ccu_nk_enable, 154 .is_enabled = ccu_nk_is_enabled, 155 156 .recalc_rate = ccu_nk_recalc_rate, 157 .round_rate = ccu_nk_round_rate, 158 .set_rate = ccu_nk_set_rate, 159}; 160EXPORT_SYMBOL_NS_GPL(ccu_nk_ops, SUNXI_CCU);