1 /* 2 * Copyright (c) 2013 Samsung Electronics Co., Ltd. 3 * Copyright (c) 2013 Linaro Ltd. 4 * Author: Thomas Abraham <thomas.ab@samsung.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * This file includes utility functions to register clocks to common 11 * clock framework for Samsung platforms. 12 */ 13 14 #include <linux/of_address.h> 15 #include <linux/syscore_ops.h> 16 17 #include "clk.h" 18 19 static LIST_HEAD(clock_reg_cache_list); 20 21 void samsung_clk_save(void __iomem *base, 22 struct samsung_clk_reg_dump *rd, 23 unsigned int num_regs) 24 { 25 for (; num_regs > 0; --num_regs, ++rd) 26 rd->value = readl(base + rd->offset); 27 } 28 29 void samsung_clk_restore(void __iomem *base, 30 const struct samsung_clk_reg_dump *rd, 31 unsigned int num_regs) 32 { 33 for (; num_regs > 0; --num_regs, ++rd) 34 writel(rd->value, base + rd->offset); 35 } 36 37 struct samsung_clk_reg_dump *samsung_clk_alloc_reg_dump( 38 const unsigned long *rdump, 39 unsigned long nr_rdump) 40 { 41 struct samsung_clk_reg_dump *rd; 42 unsigned int i; 43 44 rd = kcalloc(nr_rdump, sizeof(*rd), GFP_KERNEL); 45 if (!rd) 46 return NULL; 47 48 for (i = 0; i < nr_rdump; ++i) 49 rd[i].offset = rdump[i]; 50 51 return rd; 52 } 53 54 /* setup the essentials required to support clock lookup using ccf */ 55 struct samsung_clk_provider *__init samsung_clk_init(struct device_node *np, 56 void __iomem *base, unsigned long nr_clks) 57 { 58 struct samsung_clk_provider *ctx; 59 struct clk **clk_table; 60 int i; 61 62 ctx = kzalloc(sizeof(struct samsung_clk_provider), GFP_KERNEL); 63 if (!ctx) 64 panic("could not allocate clock provider context.\n"); 65 66 clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL); 67 if (!clk_table) 68 panic("could not allocate clock lookup table\n"); 69 70 for (i = 0; i < nr_clks; ++i) 71 clk_table[i] = ERR_PTR(-ENOENT); 72 73 ctx->reg_base = base; 74 ctx->clk_data.clks = clk_table; 75 ctx->clk_data.clk_num = nr_clks; 76 spin_lock_init(&ctx->lock); 77 78 return ctx; 79 } 80 81 void __init samsung_clk_of_add_provider(struct device_node *np, 82 struct samsung_clk_provider *ctx) 83 { 84 if (np) { 85 if (of_clk_add_provider(np, of_clk_src_onecell_get, 86 &ctx->clk_data)) 87 panic("could not register clk provider\n"); 88 } 89 } 90 91 /* add a clock instance to the clock lookup table used for dt based lookup */ 92 void samsung_clk_add_lookup(struct samsung_clk_provider *ctx, struct clk *clk, 93 unsigned int id) 94 { 95 if (ctx->clk_data.clks && id) 96 ctx->clk_data.clks[id] = clk; 97 } 98 99 /* register a list of aliases */ 100 void __init samsung_clk_register_alias(struct samsung_clk_provider *ctx, 101 const struct samsung_clock_alias *list, 102 unsigned int nr_clk) 103 { 104 struct clk *clk; 105 unsigned int idx, ret; 106 107 if (!ctx->clk_data.clks) { 108 pr_err("%s: clock table missing\n", __func__); 109 return; 110 } 111 112 for (idx = 0; idx < nr_clk; idx++, list++) { 113 if (!list->id) { 114 pr_err("%s: clock id missing for index %d\n", __func__, 115 idx); 116 continue; 117 } 118 119 clk = ctx->clk_data.clks[list->id]; 120 if (!clk) { 121 pr_err("%s: failed to find clock %d\n", __func__, 122 list->id); 123 continue; 124 } 125 126 ret = clk_register_clkdev(clk, list->alias, list->dev_name); 127 if (ret) 128 pr_err("%s: failed to register lookup %s\n", 129 __func__, list->alias); 130 } 131 } 132 133 /* register a list of fixed clocks */ 134 void __init samsung_clk_register_fixed_rate(struct samsung_clk_provider *ctx, 135 const struct samsung_fixed_rate_clock *list, 136 unsigned int nr_clk) 137 { 138 struct clk *clk; 139 unsigned int idx, ret; 140 141 for (idx = 0; idx < nr_clk; idx++, list++) { 142 clk = clk_register_fixed_rate(NULL, list->name, 143 list->parent_name, list->flags, list->fixed_rate); 144 if (IS_ERR(clk)) { 145 pr_err("%s: failed to register clock %s\n", __func__, 146 list->name); 147 continue; 148 } 149 150 samsung_clk_add_lookup(ctx, clk, list->id); 151 152 /* 153 * Unconditionally add a clock lookup for the fixed rate clocks. 154 * There are not many of these on any of Samsung platforms. 155 */ 156 ret = clk_register_clkdev(clk, list->name, NULL); 157 if (ret) 158 pr_err("%s: failed to register clock lookup for %s", 159 __func__, list->name); 160 } 161 } 162 163 /* register a list of fixed factor clocks */ 164 void __init samsung_clk_register_fixed_factor(struct samsung_clk_provider *ctx, 165 const struct samsung_fixed_factor_clock *list, unsigned int nr_clk) 166 { 167 struct clk *clk; 168 unsigned int idx; 169 170 for (idx = 0; idx < nr_clk; idx++, list++) { 171 clk = clk_register_fixed_factor(NULL, list->name, 172 list->parent_name, list->flags, list->mult, list->div); 173 if (IS_ERR(clk)) { 174 pr_err("%s: failed to register clock %s\n", __func__, 175 list->name); 176 continue; 177 } 178 179 samsung_clk_add_lookup(ctx, clk, list->id); 180 } 181 } 182 183 /* register a list of mux clocks */ 184 void __init samsung_clk_register_mux(struct samsung_clk_provider *ctx, 185 const struct samsung_mux_clock *list, 186 unsigned int nr_clk) 187 { 188 struct clk *clk; 189 unsigned int idx, ret; 190 191 for (idx = 0; idx < nr_clk; idx++, list++) { 192 clk = clk_register_mux(NULL, list->name, list->parent_names, 193 list->num_parents, list->flags, 194 ctx->reg_base + list->offset, 195 list->shift, list->width, list->mux_flags, &ctx->lock); 196 if (IS_ERR(clk)) { 197 pr_err("%s: failed to register clock %s\n", __func__, 198 list->name); 199 continue; 200 } 201 202 samsung_clk_add_lookup(ctx, clk, list->id); 203 204 /* register a clock lookup only if a clock alias is specified */ 205 if (list->alias) { 206 ret = clk_register_clkdev(clk, list->alias, 207 list->dev_name); 208 if (ret) 209 pr_err("%s: failed to register lookup %s\n", 210 __func__, list->alias); 211 } 212 } 213 } 214 215 /* register a list of div clocks */ 216 void __init samsung_clk_register_div(struct samsung_clk_provider *ctx, 217 const struct samsung_div_clock *list, 218 unsigned int nr_clk) 219 { 220 struct clk *clk; 221 unsigned int idx, ret; 222 223 for (idx = 0; idx < nr_clk; idx++, list++) { 224 if (list->table) 225 clk = clk_register_divider_table(NULL, list->name, 226 list->parent_name, list->flags, 227 ctx->reg_base + list->offset, 228 list->shift, list->width, list->div_flags, 229 list->table, &ctx->lock); 230 else 231 clk = clk_register_divider(NULL, list->name, 232 list->parent_name, list->flags, 233 ctx->reg_base + list->offset, list->shift, 234 list->width, list->div_flags, &ctx->lock); 235 if (IS_ERR(clk)) { 236 pr_err("%s: failed to register clock %s\n", __func__, 237 list->name); 238 continue; 239 } 240 241 samsung_clk_add_lookup(ctx, clk, list->id); 242 243 /* register a clock lookup only if a clock alias is specified */ 244 if (list->alias) { 245 ret = clk_register_clkdev(clk, list->alias, 246 list->dev_name); 247 if (ret) 248 pr_err("%s: failed to register lookup %s\n", 249 __func__, list->alias); 250 } 251 } 252 } 253 254 /* register a list of gate clocks */ 255 void __init samsung_clk_register_gate(struct samsung_clk_provider *ctx, 256 const struct samsung_gate_clock *list, 257 unsigned int nr_clk) 258 { 259 struct clk *clk; 260 unsigned int idx, ret; 261 262 for (idx = 0; idx < nr_clk; idx++, list++) { 263 clk = clk_register_gate(NULL, list->name, list->parent_name, 264 list->flags, ctx->reg_base + list->offset, 265 list->bit_idx, list->gate_flags, &ctx->lock); 266 if (IS_ERR(clk)) { 267 pr_err("%s: failed to register clock %s\n", __func__, 268 list->name); 269 continue; 270 } 271 272 /* register a clock lookup only if a clock alias is specified */ 273 if (list->alias) { 274 ret = clk_register_clkdev(clk, list->alias, 275 list->dev_name); 276 if (ret) 277 pr_err("%s: failed to register lookup %s\n", 278 __func__, list->alias); 279 } 280 281 samsung_clk_add_lookup(ctx, clk, list->id); 282 } 283 } 284 285 /* 286 * obtain the clock speed of all external fixed clock sources from device 287 * tree and register it 288 */ 289 void __init samsung_clk_of_register_fixed_ext(struct samsung_clk_provider *ctx, 290 struct samsung_fixed_rate_clock *fixed_rate_clk, 291 unsigned int nr_fixed_rate_clk, 292 const struct of_device_id *clk_matches) 293 { 294 const struct of_device_id *match; 295 struct device_node *clk_np; 296 u32 freq; 297 298 for_each_matching_node_and_match(clk_np, clk_matches, &match) { 299 if (of_property_read_u32(clk_np, "clock-frequency", &freq)) 300 continue; 301 fixed_rate_clk[(unsigned long)match->data].fixed_rate = freq; 302 } 303 samsung_clk_register_fixed_rate(ctx, fixed_rate_clk, nr_fixed_rate_clk); 304 } 305 306 /* utility function to get the rate of a specified clock */ 307 unsigned long _get_rate(const char *clk_name) 308 { 309 struct clk *clk; 310 311 clk = __clk_lookup(clk_name); 312 if (!clk) { 313 pr_err("%s: could not find clock %s\n", __func__, clk_name); 314 return 0; 315 } 316 317 return clk_get_rate(clk); 318 } 319 320 #ifdef CONFIG_PM_SLEEP 321 static int samsung_clk_suspend(void) 322 { 323 struct samsung_clock_reg_cache *reg_cache; 324 325 list_for_each_entry(reg_cache, &clock_reg_cache_list, node) 326 samsung_clk_save(reg_cache->reg_base, reg_cache->rdump, 327 reg_cache->rd_num); 328 return 0; 329 } 330 331 static void samsung_clk_resume(void) 332 { 333 struct samsung_clock_reg_cache *reg_cache; 334 335 list_for_each_entry(reg_cache, &clock_reg_cache_list, node) 336 samsung_clk_restore(reg_cache->reg_base, reg_cache->rdump, 337 reg_cache->rd_num); 338 } 339 340 static struct syscore_ops samsung_clk_syscore_ops = { 341 .suspend = samsung_clk_suspend, 342 .resume = samsung_clk_resume, 343 }; 344 345 static void samsung_clk_sleep_init(void __iomem *reg_base, 346 const unsigned long *rdump, 347 unsigned long nr_rdump) 348 { 349 struct samsung_clock_reg_cache *reg_cache; 350 351 reg_cache = kzalloc(sizeof(struct samsung_clock_reg_cache), 352 GFP_KERNEL); 353 if (!reg_cache) 354 panic("could not allocate register reg_cache.\n"); 355 reg_cache->rdump = samsung_clk_alloc_reg_dump(rdump, nr_rdump); 356 357 if (!reg_cache->rdump) 358 panic("could not allocate register dump storage.\n"); 359 360 if (list_empty(&clock_reg_cache_list)) 361 register_syscore_ops(&samsung_clk_syscore_ops); 362 363 reg_cache->reg_base = reg_base; 364 reg_cache->rd_num = nr_rdump; 365 list_add_tail(®_cache->node, &clock_reg_cache_list); 366 } 367 368 #else 369 static void samsung_clk_sleep_init(void __iomem *reg_base, 370 const unsigned long *rdump, 371 unsigned long nr_rdump) {} 372 #endif 373 374 /* 375 * Common function which registers plls, muxes, dividers and gates 376 * for each CMU. It also add CMU register list to register cache. 377 */ 378 struct samsung_clk_provider * __init samsung_cmu_register_one( 379 struct device_node *np, 380 struct samsung_cmu_info *cmu) 381 { 382 void __iomem *reg_base; 383 struct samsung_clk_provider *ctx; 384 385 reg_base = of_iomap(np, 0); 386 if (!reg_base) { 387 panic("%s: failed to map registers\n", __func__); 388 return NULL; 389 } 390 391 ctx = samsung_clk_init(np, reg_base, cmu->nr_clk_ids); 392 if (!ctx) { 393 panic("%s: unable to allocate ctx\n", __func__); 394 return ctx; 395 } 396 397 if (cmu->pll_clks) 398 samsung_clk_register_pll(ctx, cmu->pll_clks, cmu->nr_pll_clks, 399 reg_base); 400 if (cmu->mux_clks) 401 samsung_clk_register_mux(ctx, cmu->mux_clks, 402 cmu->nr_mux_clks); 403 if (cmu->div_clks) 404 samsung_clk_register_div(ctx, cmu->div_clks, cmu->nr_div_clks); 405 if (cmu->gate_clks) 406 samsung_clk_register_gate(ctx, cmu->gate_clks, 407 cmu->nr_gate_clks); 408 if (cmu->fixed_clks) 409 samsung_clk_register_fixed_rate(ctx, cmu->fixed_clks, 410 cmu->nr_fixed_clks); 411 if (cmu->fixed_factor_clks) 412 samsung_clk_register_fixed_factor(ctx, cmu->fixed_factor_clks, 413 cmu->nr_fixed_factor_clks); 414 if (cmu->clk_regs) 415 samsung_clk_sleep_init(reg_base, cmu->clk_regs, 416 cmu->nr_clk_regs); 417 418 samsung_clk_of_add_provider(np, ctx); 419 420 return ctx; 421 } 422