1 /* 2 * Copyright (C) 2016 Maxime Ripard 3 * Maxime Ripard <maxime.ripard@free-electrons.com> 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License as 7 * published by the Free Software Foundation; either version 2 of 8 * the License, or (at your option) any later version. 9 */ 10 11 #include <linux/clk-provider.h> 12 13 #include "ccu_gate.h" 14 #include "ccu_nkmp.h" 15 16 struct _ccu_nkmp { 17 unsigned long n, min_n, max_n; 18 unsigned long k, min_k, max_k; 19 unsigned long m, min_m, max_m; 20 unsigned long p, min_p, max_p; 21 }; 22 23 static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate, 24 struct _ccu_nkmp *nkmp) 25 { 26 unsigned long best_rate = 0; 27 unsigned long best_n = 0, best_k = 0, best_m = 0, best_p = 0; 28 unsigned long _n, _k, _m, _p; 29 30 for (_k = nkmp->min_k; _k <= nkmp->max_k; _k++) { 31 for (_n = nkmp->min_n; _n <= nkmp->max_n; _n++) { 32 for (_m = nkmp->min_m; _m <= nkmp->max_m; _m++) { 33 for (_p = nkmp->min_p; _p <= nkmp->max_p; _p <<= 1) { 34 unsigned long tmp_rate; 35 36 tmp_rate = parent * _n * _k / (_m * _p); 37 38 if (tmp_rate > rate) 39 continue; 40 41 if ((rate - tmp_rate) < (rate - best_rate)) { 42 best_rate = tmp_rate; 43 best_n = _n; 44 best_k = _k; 45 best_m = _m; 46 best_p = _p; 47 } 48 } 49 } 50 } 51 } 52 53 nkmp->n = best_n; 54 nkmp->k = best_k; 55 nkmp->m = best_m; 56 nkmp->p = best_p; 57 } 58 59 static void ccu_nkmp_disable(struct clk_hw *hw) 60 { 61 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); 62 63 return ccu_gate_helper_disable(&nkmp->common, nkmp->enable); 64 } 65 66 static int ccu_nkmp_enable(struct clk_hw *hw) 67 { 68 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); 69 70 return ccu_gate_helper_enable(&nkmp->common, nkmp->enable); 71 } 72 73 static int ccu_nkmp_is_enabled(struct clk_hw *hw) 74 { 75 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); 76 77 return ccu_gate_helper_is_enabled(&nkmp->common, nkmp->enable); 78 } 79 80 static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw, 81 unsigned long parent_rate) 82 { 83 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); 84 unsigned long n, m, k, p; 85 u32 reg; 86 87 reg = readl(nkmp->common.base + nkmp->common.reg); 88 89 n = reg >> nkmp->n.shift; 90 n &= (1 << nkmp->n.width) - 1; 91 n += nkmp->n.offset; 92 if (!n) 93 n++; 94 95 k = reg >> nkmp->k.shift; 96 k &= (1 << nkmp->k.width) - 1; 97 k += nkmp->k.offset; 98 if (!k) 99 k++; 100 101 m = reg >> nkmp->m.shift; 102 m &= (1 << nkmp->m.width) - 1; 103 m += nkmp->m.offset; 104 if (!m) 105 m++; 106 107 p = reg >> nkmp->p.shift; 108 p &= (1 << nkmp->p.width) - 1; 109 110 return (parent_rate * n * k >> p) / m; 111 } 112 113 static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate, 114 unsigned long *parent_rate) 115 { 116 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); 117 struct _ccu_nkmp _nkmp; 118 119 _nkmp.min_n = nkmp->n.min; 120 _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width; 121 _nkmp.min_k = nkmp->k.min; 122 _nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width; 123 _nkmp.min_m = 1; 124 _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width; 125 _nkmp.min_p = 1; 126 _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1); 127 128 ccu_nkmp_find_best(*parent_rate, rate, &_nkmp); 129 130 return *parent_rate * _nkmp.n * _nkmp.k / (_nkmp.m * _nkmp.p); 131 } 132 133 static int ccu_nkmp_set_rate(struct clk_hw *hw, unsigned long rate, 134 unsigned long parent_rate) 135 { 136 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); 137 struct _ccu_nkmp _nkmp; 138 unsigned long flags; 139 u32 reg; 140 141 _nkmp.min_n = 1; 142 _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width; 143 _nkmp.min_k = 1; 144 _nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width; 145 _nkmp.min_m = 1; 146 _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width; 147 _nkmp.min_p = 1; 148 _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1); 149 150 ccu_nkmp_find_best(parent_rate, rate, &_nkmp); 151 152 spin_lock_irqsave(nkmp->common.lock, flags); 153 154 reg = readl(nkmp->common.base + nkmp->common.reg); 155 reg &= ~GENMASK(nkmp->n.width + nkmp->n.shift - 1, nkmp->n.shift); 156 reg &= ~GENMASK(nkmp->k.width + nkmp->k.shift - 1, nkmp->k.shift); 157 reg &= ~GENMASK(nkmp->m.width + nkmp->m.shift - 1, nkmp->m.shift); 158 reg &= ~GENMASK(nkmp->p.width + nkmp->p.shift - 1, nkmp->p.shift); 159 160 reg |= (_nkmp.n - nkmp->n.offset) << nkmp->n.shift; 161 reg |= (_nkmp.k - nkmp->k.offset) << nkmp->k.shift; 162 reg |= (_nkmp.m - nkmp->m.offset) << nkmp->m.shift; 163 reg |= ilog2(_nkmp.p) << nkmp->p.shift; 164 165 writel(reg, nkmp->common.base + nkmp->common.reg); 166 167 spin_unlock_irqrestore(nkmp->common.lock, flags); 168 169 ccu_helper_wait_for_lock(&nkmp->common, nkmp->lock); 170 171 return 0; 172 } 173 174 const struct clk_ops ccu_nkmp_ops = { 175 .disable = ccu_nkmp_disable, 176 .enable = ccu_nkmp_enable, 177 .is_enabled = ccu_nkmp_is_enabled, 178 179 .recalc_rate = ccu_nkmp_recalc_rate, 180 .round_rate = ccu_nkmp_round_rate, 181 .set_rate = ccu_nkmp_set_rate, 182 }; 183