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_nkmp.h" 12 13 struct _ccu_nkmp { 14 unsigned long n, min_n, max_n; 15 unsigned long k, min_k, max_k; 16 unsigned long m, min_m, max_m; 17 unsigned long p, min_p, max_p; 18 }; 19 20 static unsigned long ccu_nkmp_calc_rate(unsigned long parent, 21 unsigned long n, unsigned long k, 22 unsigned long m, unsigned long p) 23 { 24 u64 rate = parent; 25 26 rate *= n * k; 27 do_div(rate, m * p); 28 29 return rate; 30 } 31 32 static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate, 33 struct _ccu_nkmp *nkmp) 34 { 35 unsigned long best_rate = 0; 36 unsigned long best_n = 0, best_k = 0, best_m = 0, best_p = 0; 37 unsigned long _n, _k, _m, _p; 38 39 for (_k = nkmp->min_k; _k <= nkmp->max_k; _k++) { 40 for (_n = nkmp->min_n; _n <= nkmp->max_n; _n++) { 41 for (_m = nkmp->min_m; _m <= nkmp->max_m; _m++) { 42 for (_p = nkmp->min_p; _p <= nkmp->max_p; _p <<= 1) { 43 unsigned long tmp_rate; 44 45 tmp_rate = ccu_nkmp_calc_rate(parent, 46 _n, _k, 47 _m, _p); 48 49 if (tmp_rate > rate) 50 continue; 51 52 if ((rate - tmp_rate) < (rate - best_rate)) { 53 best_rate = tmp_rate; 54 best_n = _n; 55 best_k = _k; 56 best_m = _m; 57 best_p = _p; 58 } 59 } 60 } 61 } 62 } 63 64 nkmp->n = best_n; 65 nkmp->k = best_k; 66 nkmp->m = best_m; 67 nkmp->p = best_p; 68 } 69 70 static void ccu_nkmp_disable(struct clk_hw *hw) 71 { 72 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); 73 74 return ccu_gate_helper_disable(&nkmp->common, nkmp->enable); 75 } 76 77 static int ccu_nkmp_enable(struct clk_hw *hw) 78 { 79 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); 80 81 return ccu_gate_helper_enable(&nkmp->common, nkmp->enable); 82 } 83 84 static int ccu_nkmp_is_enabled(struct clk_hw *hw) 85 { 86 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); 87 88 return ccu_gate_helper_is_enabled(&nkmp->common, nkmp->enable); 89 } 90 91 static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw, 92 unsigned long parent_rate) 93 { 94 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); 95 unsigned long n, m, k, p, rate; 96 u32 reg; 97 98 reg = readl(nkmp->common.base + nkmp->common.reg); 99 100 n = reg >> nkmp->n.shift; 101 n &= (1 << nkmp->n.width) - 1; 102 n += nkmp->n.offset; 103 if (!n) 104 n++; 105 106 k = reg >> nkmp->k.shift; 107 k &= (1 << nkmp->k.width) - 1; 108 k += nkmp->k.offset; 109 if (!k) 110 k++; 111 112 m = reg >> nkmp->m.shift; 113 m &= (1 << nkmp->m.width) - 1; 114 m += nkmp->m.offset; 115 if (!m) 116 m++; 117 118 p = reg >> nkmp->p.shift; 119 p &= (1 << nkmp->p.width) - 1; 120 121 rate = ccu_nkmp_calc_rate(parent_rate, n, k, m, 1 << p); 122 if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) 123 rate /= nkmp->fixed_post_div; 124 125 return rate; 126 } 127 128 static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate, 129 unsigned long *parent_rate) 130 { 131 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); 132 struct _ccu_nkmp _nkmp; 133 134 if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) 135 rate *= nkmp->fixed_post_div; 136 137 if (nkmp->max_rate && rate > nkmp->max_rate) { 138 rate = nkmp->max_rate; 139 if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) 140 rate /= nkmp->fixed_post_div; 141 return rate; 142 } 143 144 _nkmp.min_n = nkmp->n.min ?: 1; 145 _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width; 146 _nkmp.min_k = nkmp->k.min ?: 1; 147 _nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width; 148 _nkmp.min_m = 1; 149 _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width; 150 _nkmp.min_p = 1; 151 _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1); 152 153 ccu_nkmp_find_best(*parent_rate, rate, &_nkmp); 154 155 rate = ccu_nkmp_calc_rate(*parent_rate, _nkmp.n, _nkmp.k, 156 _nkmp.m, _nkmp.p); 157 if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) 158 rate = rate / nkmp->fixed_post_div; 159 160 return rate; 161 } 162 163 static int ccu_nkmp_set_rate(struct clk_hw *hw, unsigned long rate, 164 unsigned long parent_rate) 165 { 166 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); 167 u32 n_mask = 0, k_mask = 0, m_mask = 0, p_mask = 0; 168 struct _ccu_nkmp _nkmp; 169 unsigned long flags; 170 u32 reg; 171 172 if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) 173 rate = rate * nkmp->fixed_post_div; 174 175 _nkmp.min_n = nkmp->n.min ?: 1; 176 _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width; 177 _nkmp.min_k = nkmp->k.min ?: 1; 178 _nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width; 179 _nkmp.min_m = 1; 180 _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width; 181 _nkmp.min_p = 1; 182 _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1); 183 184 ccu_nkmp_find_best(parent_rate, rate, &_nkmp); 185 186 /* 187 * If width is 0, GENMASK() macro may not generate expected mask (0) 188 * as it falls under undefined behaviour by C standard due to shifts 189 * which are equal or greater than width of left operand. This can 190 * be easily avoided by explicitly checking if width is 0. 191 */ 192 if (nkmp->n.width) 193 n_mask = GENMASK(nkmp->n.width + nkmp->n.shift - 1, 194 nkmp->n.shift); 195 if (nkmp->k.width) 196 k_mask = GENMASK(nkmp->k.width + nkmp->k.shift - 1, 197 nkmp->k.shift); 198 if (nkmp->m.width) 199 m_mask = GENMASK(nkmp->m.width + nkmp->m.shift - 1, 200 nkmp->m.shift); 201 if (nkmp->p.width) 202 p_mask = GENMASK(nkmp->p.width + nkmp->p.shift - 1, 203 nkmp->p.shift); 204 205 spin_lock_irqsave(nkmp->common.lock, flags); 206 207 reg = readl(nkmp->common.base + nkmp->common.reg); 208 reg &= ~(n_mask | k_mask | m_mask | p_mask); 209 210 reg |= ((_nkmp.n - nkmp->n.offset) << nkmp->n.shift) & n_mask; 211 reg |= ((_nkmp.k - nkmp->k.offset) << nkmp->k.shift) & k_mask; 212 reg |= ((_nkmp.m - nkmp->m.offset) << nkmp->m.shift) & m_mask; 213 reg |= (ilog2(_nkmp.p) << nkmp->p.shift) & p_mask; 214 215 writel(reg, nkmp->common.base + nkmp->common.reg); 216 217 spin_unlock_irqrestore(nkmp->common.lock, flags); 218 219 ccu_helper_wait_for_lock(&nkmp->common, nkmp->lock); 220 221 return 0; 222 } 223 224 const struct clk_ops ccu_nkmp_ops = { 225 .disable = ccu_nkmp_disable, 226 .enable = ccu_nkmp_enable, 227 .is_enabled = ccu_nkmp_is_enabled, 228 229 .recalc_rate = ccu_nkmp_recalc_rate, 230 .round_rate = ccu_nkmp_round_rate, 231 .set_rate = ccu_nkmp_set_rate, 232 }; 233 EXPORT_SYMBOL_NS_GPL(ccu_nkmp_ops, SUNXI_CCU); 234