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 13 struct _ccu_nk { 14 unsigned long n, min_n, max_n; 15 unsigned long k, min_k, max_k; 16 }; 17 18 static unsigned long 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 return best_rate; 44 } 45 46 static void ccu_nk_disable(struct clk_hw *hw) 47 { 48 struct ccu_nk *nk = hw_to_ccu_nk(hw); 49 50 return ccu_gate_helper_disable(&nk->common, nk->enable); 51 } 52 53 static int ccu_nk_enable(struct clk_hw *hw) 54 { 55 struct ccu_nk *nk = hw_to_ccu_nk(hw); 56 57 return ccu_gate_helper_enable(&nk->common, nk->enable); 58 } 59 60 static int ccu_nk_is_enabled(struct clk_hw *hw) 61 { 62 struct ccu_nk *nk = hw_to_ccu_nk(hw); 63 64 return ccu_gate_helper_is_enabled(&nk->common, nk->enable); 65 } 66 67 static unsigned long ccu_nk_recalc_rate(struct clk_hw *hw, 68 unsigned long parent_rate) 69 { 70 struct ccu_nk *nk = hw_to_ccu_nk(hw); 71 unsigned long rate, n, k; 72 u32 reg; 73 74 reg = readl(nk->common.base + nk->common.reg); 75 76 n = reg >> nk->n.shift; 77 n &= (1 << nk->n.width) - 1; 78 n += nk->n.offset; 79 if (!n) 80 n++; 81 82 k = reg >> nk->k.shift; 83 k &= (1 << nk->k.width) - 1; 84 k += nk->k.offset; 85 if (!k) 86 k++; 87 88 rate = parent_rate * n * k; 89 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) 90 rate /= nk->fixed_post_div; 91 92 return rate; 93 } 94 95 static long ccu_nk_round_rate(struct clk_hw *hw, unsigned long rate, 96 unsigned long *parent_rate) 97 { 98 struct ccu_nk *nk = hw_to_ccu_nk(hw); 99 struct _ccu_nk _nk; 100 101 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) 102 rate *= nk->fixed_post_div; 103 104 _nk.min_n = nk->n.min ?: 1; 105 _nk.max_n = nk->n.max ?: 1 << nk->n.width; 106 _nk.min_k = nk->k.min ?: 1; 107 _nk.max_k = nk->k.max ?: 1 << nk->k.width; 108 109 rate = ccu_nk_find_best(*parent_rate, rate, &_nk); 110 111 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) 112 rate = rate / nk->fixed_post_div; 113 114 return rate; 115 } 116 117 static int ccu_nk_set_rate(struct clk_hw *hw, unsigned long rate, 118 unsigned long parent_rate) 119 { 120 struct ccu_nk *nk = hw_to_ccu_nk(hw); 121 unsigned long flags; 122 struct _ccu_nk _nk; 123 u32 reg; 124 125 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) 126 rate = rate * nk->fixed_post_div; 127 128 _nk.min_n = nk->n.min ?: 1; 129 _nk.max_n = nk->n.max ?: 1 << nk->n.width; 130 _nk.min_k = nk->k.min ?: 1; 131 _nk.max_k = nk->k.max ?: 1 << nk->k.width; 132 133 ccu_nk_find_best(parent_rate, rate, &_nk); 134 135 spin_lock_irqsave(nk->common.lock, flags); 136 137 reg = readl(nk->common.base + nk->common.reg); 138 reg &= ~GENMASK(nk->n.width + nk->n.shift - 1, nk->n.shift); 139 reg &= ~GENMASK(nk->k.width + nk->k.shift - 1, nk->k.shift); 140 141 reg |= (_nk.k - nk->k.offset) << nk->k.shift; 142 reg |= (_nk.n - nk->n.offset) << nk->n.shift; 143 writel(reg, nk->common.base + nk->common.reg); 144 145 spin_unlock_irqrestore(nk->common.lock, flags); 146 147 ccu_helper_wait_for_lock(&nk->common, nk->lock); 148 149 return 0; 150 } 151 152 const struct clk_ops ccu_nk_ops = { 153 .disable = ccu_nk_disable, 154 .enable = ccu_nk_enable, 155 .is_enabled = ccu_nk_is_enabled, 156 157 .recalc_rate = ccu_nk_recalc_rate, 158 .round_rate = ccu_nk_round_rate, 159 .set_rate = ccu_nk_set_rate, 160 }; 161 EXPORT_SYMBOL_NS_GPL(ccu_nk_ops, SUNXI_CCU); 162