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_nkm.h" 15 16 struct _ccu_nkm { 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 }; 21 22 static void ccu_nkm_find_best(unsigned long parent, unsigned long rate, 23 struct _ccu_nkm *nkm) 24 { 25 unsigned long best_rate = 0; 26 unsigned long best_n = 0, best_k = 0, best_m = 0; 27 unsigned long _n, _k, _m; 28 29 for (_k = nkm->min_k; _k <= nkm->max_k; _k++) { 30 for (_n = nkm->min_n; _n <= nkm->max_n; _n++) { 31 for (_m = nkm->min_m; _m <= nkm->max_m; _m++) { 32 unsigned long tmp_rate; 33 34 tmp_rate = parent * _n * _k / _m; 35 36 if (tmp_rate > rate) 37 continue; 38 if ((rate - tmp_rate) < (rate - best_rate)) { 39 best_rate = tmp_rate; 40 best_n = _n; 41 best_k = _k; 42 best_m = _m; 43 } 44 } 45 } 46 } 47 48 nkm->n = best_n; 49 nkm->k = best_k; 50 nkm->m = best_m; 51 } 52 53 static void ccu_nkm_disable(struct clk_hw *hw) 54 { 55 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 56 57 return ccu_gate_helper_disable(&nkm->common, nkm->enable); 58 } 59 60 static int ccu_nkm_enable(struct clk_hw *hw) 61 { 62 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 63 64 return ccu_gate_helper_enable(&nkm->common, nkm->enable); 65 } 66 67 static int ccu_nkm_is_enabled(struct clk_hw *hw) 68 { 69 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 70 71 return ccu_gate_helper_is_enabled(&nkm->common, nkm->enable); 72 } 73 74 static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw, 75 unsigned long parent_rate) 76 { 77 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 78 unsigned long n, m, k; 79 u32 reg; 80 81 reg = readl(nkm->common.base + nkm->common.reg); 82 83 n = reg >> nkm->n.shift; 84 n &= (1 << nkm->n.width) - 1; 85 n += nkm->n.offset; 86 if (!n) 87 n++; 88 89 k = reg >> nkm->k.shift; 90 k &= (1 << nkm->k.width) - 1; 91 k += nkm->k.offset; 92 if (!k) 93 k++; 94 95 m = reg >> nkm->m.shift; 96 m &= (1 << nkm->m.width) - 1; 97 m += nkm->m.offset; 98 if (!m) 99 m++; 100 101 return parent_rate * n * k / m; 102 } 103 104 static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux, 105 unsigned long parent_rate, 106 unsigned long rate, 107 void *data) 108 { 109 struct ccu_nkm *nkm = data; 110 struct _ccu_nkm _nkm; 111 112 _nkm.min_n = nkm->n.min; 113 _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width; 114 _nkm.min_k = nkm->k.min; 115 _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width; 116 _nkm.min_m = 1; 117 _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width; 118 119 ccu_nkm_find_best(parent_rate, rate, &_nkm); 120 121 return parent_rate * _nkm.n * _nkm.k / _nkm.m; 122 } 123 124 static int ccu_nkm_determine_rate(struct clk_hw *hw, 125 struct clk_rate_request *req) 126 { 127 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 128 129 return ccu_mux_helper_determine_rate(&nkm->common, &nkm->mux, 130 req, ccu_nkm_round_rate, nkm); 131 } 132 133 static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate, 134 unsigned long parent_rate) 135 { 136 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 137 struct _ccu_nkm _nkm; 138 unsigned long flags; 139 u32 reg; 140 141 _nkm.min_n = nkm->n.min; 142 _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width; 143 _nkm.min_k = nkm->k.min; 144 _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width; 145 _nkm.min_m = 1; 146 _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width; 147 148 ccu_nkm_find_best(parent_rate, rate, &_nkm); 149 150 spin_lock_irqsave(nkm->common.lock, flags); 151 152 reg = readl(nkm->common.base + nkm->common.reg); 153 reg &= ~GENMASK(nkm->n.width + nkm->n.shift - 1, nkm->n.shift); 154 reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift); 155 reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift); 156 157 reg |= (_nkm.n - nkm->n.offset) << nkm->n.shift; 158 reg |= (_nkm.k - nkm->k.offset) << nkm->k.shift; 159 reg |= (_nkm.m - nkm->m.offset) << nkm->m.shift; 160 writel(reg, nkm->common.base + nkm->common.reg); 161 162 spin_unlock_irqrestore(nkm->common.lock, flags); 163 164 ccu_helper_wait_for_lock(&nkm->common, nkm->lock); 165 166 return 0; 167 } 168 169 static u8 ccu_nkm_get_parent(struct clk_hw *hw) 170 { 171 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 172 173 return ccu_mux_helper_get_parent(&nkm->common, &nkm->mux); 174 } 175 176 static int ccu_nkm_set_parent(struct clk_hw *hw, u8 index) 177 { 178 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 179 180 return ccu_mux_helper_set_parent(&nkm->common, &nkm->mux, index); 181 } 182 183 const struct clk_ops ccu_nkm_ops = { 184 .disable = ccu_nkm_disable, 185 .enable = ccu_nkm_enable, 186 .is_enabled = ccu_nkm_is_enabled, 187 188 .get_parent = ccu_nkm_get_parent, 189 .set_parent = ccu_nkm_set_parent, 190 191 .determine_rate = ccu_nkm_determine_rate, 192 .recalc_rate = ccu_nkm_recalc_rate, 193 .set_rate = ccu_nkm_set_rate, 194 }; 195