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 #include <linux/io.h> 13 14 #include "ccu_gate.h" 15 #include "ccu_nkm.h" 16 17 struct _ccu_nkm { 18 unsigned long n, min_n, max_n; 19 unsigned long k, min_k, max_k; 20 unsigned long m, min_m, max_m; 21 }; 22 23 static void ccu_nkm_find_best(unsigned long parent, unsigned long rate, 24 struct _ccu_nkm *nkm) 25 { 26 unsigned long best_rate = 0; 27 unsigned long best_n = 0, best_k = 0, best_m = 0; 28 unsigned long _n, _k, _m; 29 30 for (_k = nkm->min_k; _k <= nkm->max_k; _k++) { 31 for (_n = nkm->min_n; _n <= nkm->max_n; _n++) { 32 for (_m = nkm->min_m; _m <= nkm->max_m; _m++) { 33 unsigned long tmp_rate; 34 35 tmp_rate = parent * _n * _k / _m; 36 37 if (tmp_rate > rate) 38 continue; 39 if ((rate - tmp_rate) < (rate - best_rate)) { 40 best_rate = tmp_rate; 41 best_n = _n; 42 best_k = _k; 43 best_m = _m; 44 } 45 } 46 } 47 } 48 49 nkm->n = best_n; 50 nkm->k = best_k; 51 nkm->m = best_m; 52 } 53 54 static void ccu_nkm_disable(struct clk_hw *hw) 55 { 56 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 57 58 return ccu_gate_helper_disable(&nkm->common, nkm->enable); 59 } 60 61 static int ccu_nkm_enable(struct clk_hw *hw) 62 { 63 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 64 65 return ccu_gate_helper_enable(&nkm->common, nkm->enable); 66 } 67 68 static int ccu_nkm_is_enabled(struct clk_hw *hw) 69 { 70 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 71 72 return ccu_gate_helper_is_enabled(&nkm->common, nkm->enable); 73 } 74 75 static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw, 76 unsigned long parent_rate) 77 { 78 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 79 unsigned long n, m, k, rate; 80 u32 reg; 81 82 reg = readl(nkm->common.base + nkm->common.reg); 83 84 n = reg >> nkm->n.shift; 85 n &= (1 << nkm->n.width) - 1; 86 n += nkm->n.offset; 87 if (!n) 88 n++; 89 90 k = reg >> nkm->k.shift; 91 k &= (1 << nkm->k.width) - 1; 92 k += nkm->k.offset; 93 if (!k) 94 k++; 95 96 m = reg >> nkm->m.shift; 97 m &= (1 << nkm->m.width) - 1; 98 m += nkm->m.offset; 99 if (!m) 100 m++; 101 102 rate = parent_rate * n * k / m; 103 104 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV) 105 rate /= nkm->fixed_post_div; 106 107 return rate; 108 } 109 110 static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux, 111 struct clk_hw *hw, 112 unsigned long *parent_rate, 113 unsigned long rate, 114 void *data) 115 { 116 struct ccu_nkm *nkm = data; 117 struct _ccu_nkm _nkm; 118 119 _nkm.min_n = nkm->n.min ?: 1; 120 _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width; 121 _nkm.min_k = nkm->k.min ?: 1; 122 _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width; 123 _nkm.min_m = 1; 124 _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width; 125 126 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV) 127 rate *= nkm->fixed_post_div; 128 129 ccu_nkm_find_best(*parent_rate, rate, &_nkm); 130 131 rate = *parent_rate * _nkm.n * _nkm.k / _nkm.m; 132 133 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV) 134 rate /= nkm->fixed_post_div; 135 136 return rate; 137 } 138 139 static int ccu_nkm_determine_rate(struct clk_hw *hw, 140 struct clk_rate_request *req) 141 { 142 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 143 144 return ccu_mux_helper_determine_rate(&nkm->common, &nkm->mux, 145 req, ccu_nkm_round_rate, nkm); 146 } 147 148 static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate, 149 unsigned long parent_rate) 150 { 151 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 152 struct _ccu_nkm _nkm; 153 unsigned long flags; 154 u32 reg; 155 156 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV) 157 rate *= nkm->fixed_post_div; 158 159 _nkm.min_n = nkm->n.min ?: 1; 160 _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width; 161 _nkm.min_k = nkm->k.min ?: 1; 162 _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width; 163 _nkm.min_m = 1; 164 _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width; 165 166 ccu_nkm_find_best(parent_rate, rate, &_nkm); 167 168 spin_lock_irqsave(nkm->common.lock, flags); 169 170 reg = readl(nkm->common.base + nkm->common.reg); 171 reg &= ~GENMASK(nkm->n.width + nkm->n.shift - 1, nkm->n.shift); 172 reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift); 173 reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift); 174 175 reg |= (_nkm.n - nkm->n.offset) << nkm->n.shift; 176 reg |= (_nkm.k - nkm->k.offset) << nkm->k.shift; 177 reg |= (_nkm.m - nkm->m.offset) << nkm->m.shift; 178 writel(reg, nkm->common.base + nkm->common.reg); 179 180 spin_unlock_irqrestore(nkm->common.lock, flags); 181 182 ccu_helper_wait_for_lock(&nkm->common, nkm->lock); 183 184 return 0; 185 } 186 187 static u8 ccu_nkm_get_parent(struct clk_hw *hw) 188 { 189 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 190 191 return ccu_mux_helper_get_parent(&nkm->common, &nkm->mux); 192 } 193 194 static int ccu_nkm_set_parent(struct clk_hw *hw, u8 index) 195 { 196 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); 197 198 return ccu_mux_helper_set_parent(&nkm->common, &nkm->mux, index); 199 } 200 201 const struct clk_ops ccu_nkm_ops = { 202 .disable = ccu_nkm_disable, 203 .enable = ccu_nkm_enable, 204 .is_enabled = ccu_nkm_is_enabled, 205 206 .get_parent = ccu_nkm_get_parent, 207 .set_parent = ccu_nkm_set_parent, 208 209 .determine_rate = ccu_nkm_determine_rate, 210 .recalc_rate = ccu_nkm_recalc_rate, 211 .set_rate = ccu_nkm_set_rate, 212 }; 213