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_mp.h" 12 13 static void ccu_mp_find_best(unsigned long parent, unsigned long rate, 14 unsigned int max_m, unsigned int max_p, 15 unsigned int *m, unsigned int *p) 16 { 17 unsigned long best_rate = 0; 18 unsigned int best_m = 0, best_p = 0; 19 unsigned int _m, _p; 20 21 for (_p = 1; _p <= max_p; _p <<= 1) { 22 for (_m = 1; _m <= max_m; _m++) { 23 unsigned long tmp_rate = parent / _p / _m; 24 25 if (tmp_rate > rate) 26 continue; 27 28 if ((rate - tmp_rate) < (rate - best_rate)) { 29 best_rate = tmp_rate; 30 best_m = _m; 31 best_p = _p; 32 } 33 } 34 } 35 36 *m = best_m; 37 *p = best_p; 38 } 39 40 static unsigned long ccu_mp_find_best_with_parent_adj(struct clk_hw *hw, 41 unsigned long *parent, 42 unsigned long rate, 43 unsigned int max_m, 44 unsigned int max_p) 45 { 46 unsigned long parent_rate_saved; 47 unsigned long parent_rate, now; 48 unsigned long best_rate = 0; 49 unsigned int _m, _p, div; 50 unsigned long maxdiv; 51 52 parent_rate_saved = *parent; 53 54 /* 55 * The maximum divider we can use without overflowing 56 * unsigned long in rate * m * p below 57 */ 58 maxdiv = max_m * max_p; 59 maxdiv = min(ULONG_MAX / rate, maxdiv); 60 61 for (_p = 1; _p <= max_p; _p <<= 1) { 62 for (_m = 1; _m <= max_m; _m++) { 63 div = _m * _p; 64 65 if (div > maxdiv) 66 break; 67 68 if (rate * div == parent_rate_saved) { 69 /* 70 * It's the most ideal case if the requested 71 * rate can be divided from parent clock without 72 * needing to change parent rate, so return the 73 * divider immediately. 74 */ 75 *parent = parent_rate_saved; 76 return rate; 77 } 78 79 parent_rate = clk_hw_round_rate(hw, rate * div); 80 now = parent_rate / div; 81 82 if (now <= rate && now > best_rate) { 83 best_rate = now; 84 *parent = parent_rate; 85 86 if (now == rate) 87 return rate; 88 } 89 } 90 } 91 92 return best_rate; 93 } 94 95 static unsigned long ccu_mp_round_rate(struct ccu_mux_internal *mux, 96 struct clk_hw *hw, 97 unsigned long *parent_rate, 98 unsigned long rate, 99 void *data) 100 { 101 struct ccu_mp *cmp = data; 102 unsigned int max_m, max_p; 103 unsigned int m, p; 104 105 if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV) 106 rate *= cmp->fixed_post_div; 107 108 max_m = cmp->m.max ?: 1 << cmp->m.width; 109 max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1); 110 111 if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) { 112 ccu_mp_find_best(*parent_rate, rate, max_m, max_p, &m, &p); 113 rate = *parent_rate / p / m; 114 } else { 115 rate = ccu_mp_find_best_with_parent_adj(hw, parent_rate, rate, 116 max_m, max_p); 117 } 118 119 if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV) 120 rate /= cmp->fixed_post_div; 121 122 return rate; 123 } 124 125 static void ccu_mp_disable(struct clk_hw *hw) 126 { 127 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 128 129 return ccu_gate_helper_disable(&cmp->common, cmp->enable); 130 } 131 132 static int ccu_mp_enable(struct clk_hw *hw) 133 { 134 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 135 136 return ccu_gate_helper_enable(&cmp->common, cmp->enable); 137 } 138 139 static int ccu_mp_is_enabled(struct clk_hw *hw) 140 { 141 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 142 143 return ccu_gate_helper_is_enabled(&cmp->common, cmp->enable); 144 } 145 146 static unsigned long ccu_mp_recalc_rate(struct clk_hw *hw, 147 unsigned long parent_rate) 148 { 149 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 150 unsigned long rate; 151 unsigned int m, p; 152 u32 reg; 153 154 /* Adjust parent_rate according to pre-dividers */ 155 parent_rate = ccu_mux_helper_apply_prediv(&cmp->common, &cmp->mux, -1, 156 parent_rate); 157 158 reg = readl(cmp->common.base + cmp->common.reg); 159 160 m = reg >> cmp->m.shift; 161 m &= (1 << cmp->m.width) - 1; 162 m += cmp->m.offset; 163 if (!m) 164 m++; 165 166 p = reg >> cmp->p.shift; 167 p &= (1 << cmp->p.width) - 1; 168 169 rate = (parent_rate >> p) / m; 170 if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV) 171 rate /= cmp->fixed_post_div; 172 173 return rate; 174 } 175 176 static int ccu_mp_determine_rate(struct clk_hw *hw, 177 struct clk_rate_request *req) 178 { 179 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 180 181 return ccu_mux_helper_determine_rate(&cmp->common, &cmp->mux, 182 req, ccu_mp_round_rate, cmp); 183 } 184 185 static int ccu_mp_set_rate(struct clk_hw *hw, unsigned long rate, 186 unsigned long parent_rate) 187 { 188 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 189 unsigned long flags; 190 unsigned int max_m, max_p; 191 unsigned int m, p; 192 u32 reg; 193 194 /* Adjust parent_rate according to pre-dividers */ 195 parent_rate = ccu_mux_helper_apply_prediv(&cmp->common, &cmp->mux, -1, 196 parent_rate); 197 198 max_m = cmp->m.max ?: 1 << cmp->m.width; 199 max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1); 200 201 /* Adjust target rate according to post-dividers */ 202 if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV) 203 rate = rate * cmp->fixed_post_div; 204 205 ccu_mp_find_best(parent_rate, rate, max_m, max_p, &m, &p); 206 207 spin_lock_irqsave(cmp->common.lock, flags); 208 209 reg = readl(cmp->common.base + cmp->common.reg); 210 reg &= ~GENMASK(cmp->m.width + cmp->m.shift - 1, cmp->m.shift); 211 reg &= ~GENMASK(cmp->p.width + cmp->p.shift - 1, cmp->p.shift); 212 reg |= (m - cmp->m.offset) << cmp->m.shift; 213 reg |= ilog2(p) << cmp->p.shift; 214 215 writel(reg, cmp->common.base + cmp->common.reg); 216 217 spin_unlock_irqrestore(cmp->common.lock, flags); 218 219 return 0; 220 } 221 222 static u8 ccu_mp_get_parent(struct clk_hw *hw) 223 { 224 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 225 226 return ccu_mux_helper_get_parent(&cmp->common, &cmp->mux); 227 } 228 229 static int ccu_mp_set_parent(struct clk_hw *hw, u8 index) 230 { 231 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 232 233 return ccu_mux_helper_set_parent(&cmp->common, &cmp->mux, index); 234 } 235 236 const struct clk_ops ccu_mp_ops = { 237 .disable = ccu_mp_disable, 238 .enable = ccu_mp_enable, 239 .is_enabled = ccu_mp_is_enabled, 240 241 .get_parent = ccu_mp_get_parent, 242 .set_parent = ccu_mp_set_parent, 243 244 .determine_rate = ccu_mp_determine_rate, 245 .recalc_rate = ccu_mp_recalc_rate, 246 .set_rate = ccu_mp_set_rate, 247 }; 248 249 /* 250 * Support for MMC timing mode switching 251 * 252 * The MMC clocks on some SoCs support switching between old and 253 * new timing modes. A platform specific API is provided to query 254 * and set the timing mode on supported SoCs. 255 * 256 * In addition, a special class of ccu_mp_ops is provided, which 257 * takes in to account the timing mode switch. When the new timing 258 * mode is active, the clock output rate is halved. This new class 259 * is a wrapper around the generic ccu_mp_ops. When clock rates 260 * are passed through to ccu_mp_ops callbacks, they are doubled 261 * if the new timing mode bit is set, to account for the post 262 * divider. Conversely, when clock rates are passed back, they 263 * are halved if the mode bit is set. 264 */ 265 266 static unsigned long ccu_mp_mmc_recalc_rate(struct clk_hw *hw, 267 unsigned long parent_rate) 268 { 269 unsigned long rate = ccu_mp_recalc_rate(hw, parent_rate); 270 struct ccu_common *cm = hw_to_ccu_common(hw); 271 u32 val = readl(cm->base + cm->reg); 272 273 if (val & CCU_MMC_NEW_TIMING_MODE) 274 return rate / 2; 275 return rate; 276 } 277 278 static int ccu_mp_mmc_determine_rate(struct clk_hw *hw, 279 struct clk_rate_request *req) 280 { 281 struct ccu_common *cm = hw_to_ccu_common(hw); 282 u32 val = readl(cm->base + cm->reg); 283 int ret; 284 285 /* adjust the requested clock rate */ 286 if (val & CCU_MMC_NEW_TIMING_MODE) { 287 req->rate *= 2; 288 req->min_rate *= 2; 289 req->max_rate *= 2; 290 } 291 292 ret = ccu_mp_determine_rate(hw, req); 293 294 /* re-adjust the requested clock rate back */ 295 if (val & CCU_MMC_NEW_TIMING_MODE) { 296 req->rate /= 2; 297 req->min_rate /= 2; 298 req->max_rate /= 2; 299 } 300 301 return ret; 302 } 303 304 static int ccu_mp_mmc_set_rate(struct clk_hw *hw, unsigned long rate, 305 unsigned long parent_rate) 306 { 307 struct ccu_common *cm = hw_to_ccu_common(hw); 308 u32 val = readl(cm->base + cm->reg); 309 310 if (val & CCU_MMC_NEW_TIMING_MODE) 311 rate *= 2; 312 313 return ccu_mp_set_rate(hw, rate, parent_rate); 314 } 315 316 const struct clk_ops ccu_mp_mmc_ops = { 317 .disable = ccu_mp_disable, 318 .enable = ccu_mp_enable, 319 .is_enabled = ccu_mp_is_enabled, 320 321 .get_parent = ccu_mp_get_parent, 322 .set_parent = ccu_mp_set_parent, 323 324 .determine_rate = ccu_mp_mmc_determine_rate, 325 .recalc_rate = ccu_mp_mmc_recalc_rate, 326 .set_rate = ccu_mp_mmc_set_rate, 327 }; 328