1 /* 2 * SCI Clock driver for keystone based devices 3 * 4 * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/ 5 * Tero Kristo <t-kristo@ti.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * This program is distributed "as is" WITHOUT ANY WARRANTY of any 12 * kind, whether express or implied; without even the implied warranty 13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 */ 16 #include <linux/clk-provider.h> 17 #include <linux/err.h> 18 #include <linux/io.h> 19 #include <linux/module.h> 20 #include <linux/of_address.h> 21 #include <linux/of_device.h> 22 #include <linux/platform_device.h> 23 #include <linux/slab.h> 24 #include <linux/soc/ti/ti_sci_protocol.h> 25 #include <linux/bsearch.h> 26 #include <linux/list_sort.h> 27 28 #define SCI_CLK_SSC_ENABLE BIT(0) 29 #define SCI_CLK_ALLOW_FREQ_CHANGE BIT(1) 30 #define SCI_CLK_INPUT_TERMINATION BIT(2) 31 32 /** 33 * struct sci_clk_provider - TI SCI clock provider representation 34 * @sci: Handle to the System Control Interface protocol handler 35 * @ops: Pointer to the SCI ops to be used by the clocks 36 * @dev: Device pointer for the clock provider 37 * @clocks: Clocks array for this device 38 * @num_clocks: Total number of clocks for this provider 39 */ 40 struct sci_clk_provider { 41 const struct ti_sci_handle *sci; 42 const struct ti_sci_clk_ops *ops; 43 struct device *dev; 44 struct sci_clk **clocks; 45 int num_clocks; 46 }; 47 48 /** 49 * struct sci_clk - TI SCI clock representation 50 * @hw: Hardware clock cookie for common clock framework 51 * @dev_id: Device index 52 * @clk_id: Clock index 53 * @num_parents: Number of parents for this clock 54 * @provider: Master clock provider 55 * @flags: Flags for the clock 56 * @node: Link for handling clocks probed via DT 57 */ 58 struct sci_clk { 59 struct clk_hw hw; 60 u16 dev_id; 61 u8 clk_id; 62 u8 num_parents; 63 struct sci_clk_provider *provider; 64 u8 flags; 65 struct list_head node; 66 }; 67 68 #define to_sci_clk(_hw) container_of(_hw, struct sci_clk, hw) 69 70 /** 71 * sci_clk_prepare - Prepare (enable) a TI SCI clock 72 * @hw: clock to prepare 73 * 74 * Prepares a clock to be actively used. Returns the SCI protocol status. 75 */ 76 static int sci_clk_prepare(struct clk_hw *hw) 77 { 78 struct sci_clk *clk = to_sci_clk(hw); 79 bool enable_ssc = clk->flags & SCI_CLK_SSC_ENABLE; 80 bool allow_freq_change = clk->flags & SCI_CLK_ALLOW_FREQ_CHANGE; 81 bool input_termination = clk->flags & SCI_CLK_INPUT_TERMINATION; 82 83 return clk->provider->ops->get_clock(clk->provider->sci, clk->dev_id, 84 clk->clk_id, enable_ssc, 85 allow_freq_change, 86 input_termination); 87 } 88 89 /** 90 * sci_clk_unprepare - Un-prepares (disables) a TI SCI clock 91 * @hw: clock to unprepare 92 * 93 * Un-prepares a clock from active state. 94 */ 95 static void sci_clk_unprepare(struct clk_hw *hw) 96 { 97 struct sci_clk *clk = to_sci_clk(hw); 98 int ret; 99 100 ret = clk->provider->ops->put_clock(clk->provider->sci, clk->dev_id, 101 clk->clk_id); 102 if (ret) 103 dev_err(clk->provider->dev, 104 "unprepare failed for dev=%d, clk=%d, ret=%d\n", 105 clk->dev_id, clk->clk_id, ret); 106 } 107 108 /** 109 * sci_clk_is_prepared - Check if a TI SCI clock is prepared or not 110 * @hw: clock to check status for 111 * 112 * Checks if a clock is prepared (enabled) in hardware. Returns non-zero 113 * value if clock is enabled, zero otherwise. 114 */ 115 static int sci_clk_is_prepared(struct clk_hw *hw) 116 { 117 struct sci_clk *clk = to_sci_clk(hw); 118 bool req_state, current_state; 119 int ret; 120 121 ret = clk->provider->ops->is_on(clk->provider->sci, clk->dev_id, 122 clk->clk_id, &req_state, 123 ¤t_state); 124 if (ret) { 125 dev_err(clk->provider->dev, 126 "is_prepared failed for dev=%d, clk=%d, ret=%d\n", 127 clk->dev_id, clk->clk_id, ret); 128 return 0; 129 } 130 131 return req_state; 132 } 133 134 /** 135 * sci_clk_recalc_rate - Get clock rate for a TI SCI clock 136 * @hw: clock to get rate for 137 * @parent_rate: parent rate provided by common clock framework, not used 138 * 139 * Gets the current clock rate of a TI SCI clock. Returns the current 140 * clock rate, or zero in failure. 141 */ 142 static unsigned long sci_clk_recalc_rate(struct clk_hw *hw, 143 unsigned long parent_rate) 144 { 145 struct sci_clk *clk = to_sci_clk(hw); 146 u64 freq; 147 int ret; 148 149 ret = clk->provider->ops->get_freq(clk->provider->sci, clk->dev_id, 150 clk->clk_id, &freq); 151 if (ret) { 152 dev_err(clk->provider->dev, 153 "recalc-rate failed for dev=%d, clk=%d, ret=%d\n", 154 clk->dev_id, clk->clk_id, ret); 155 return 0; 156 } 157 158 return freq; 159 } 160 161 /** 162 * sci_clk_determine_rate - Determines a clock rate a clock can be set to 163 * @hw: clock to change rate for 164 * @req: requested rate configuration for the clock 165 * 166 * Determines a suitable clock rate and parent for a TI SCI clock. 167 * The parent handling is un-used, as generally the parent clock rates 168 * are not known by the kernel; instead these are internally handled 169 * by the firmware. Returns 0 on success, negative error value on failure. 170 */ 171 static int sci_clk_determine_rate(struct clk_hw *hw, 172 struct clk_rate_request *req) 173 { 174 struct sci_clk *clk = to_sci_clk(hw); 175 int ret; 176 u64 new_rate; 177 178 ret = clk->provider->ops->get_best_match_freq(clk->provider->sci, 179 clk->dev_id, 180 clk->clk_id, 181 req->min_rate, 182 req->rate, 183 req->max_rate, 184 &new_rate); 185 if (ret) { 186 dev_err(clk->provider->dev, 187 "determine-rate failed for dev=%d, clk=%d, ret=%d\n", 188 clk->dev_id, clk->clk_id, ret); 189 return ret; 190 } 191 192 req->rate = new_rate; 193 194 return 0; 195 } 196 197 /** 198 * sci_clk_set_rate - Set rate for a TI SCI clock 199 * @hw: clock to change rate for 200 * @rate: target rate for the clock 201 * @parent_rate: rate of the clock parent, not used for TI SCI clocks 202 * 203 * Sets a clock frequency for a TI SCI clock. Returns the TI SCI 204 * protocol status. 205 */ 206 static int sci_clk_set_rate(struct clk_hw *hw, unsigned long rate, 207 unsigned long parent_rate) 208 { 209 struct sci_clk *clk = to_sci_clk(hw); 210 211 return clk->provider->ops->set_freq(clk->provider->sci, clk->dev_id, 212 clk->clk_id, rate, rate, rate); 213 } 214 215 /** 216 * sci_clk_get_parent - Get the current parent of a TI SCI clock 217 * @hw: clock to get parent for 218 * 219 * Returns the index of the currently selected parent for a TI SCI clock. 220 */ 221 static u8 sci_clk_get_parent(struct clk_hw *hw) 222 { 223 struct sci_clk *clk = to_sci_clk(hw); 224 u8 parent_id; 225 int ret; 226 227 ret = clk->provider->ops->get_parent(clk->provider->sci, clk->dev_id, 228 clk->clk_id, &parent_id); 229 if (ret) { 230 dev_err(clk->provider->dev, 231 "get-parent failed for dev=%d, clk=%d, ret=%d\n", 232 clk->dev_id, clk->clk_id, ret); 233 return 0; 234 } 235 236 return parent_id - clk->clk_id - 1; 237 } 238 239 /** 240 * sci_clk_set_parent - Set the parent of a TI SCI clock 241 * @hw: clock to set parent for 242 * @index: new parent index for the clock 243 * 244 * Sets the parent of a TI SCI clock. Return TI SCI protocol status. 245 */ 246 static int sci_clk_set_parent(struct clk_hw *hw, u8 index) 247 { 248 struct sci_clk *clk = to_sci_clk(hw); 249 250 return clk->provider->ops->set_parent(clk->provider->sci, clk->dev_id, 251 clk->clk_id, 252 index + 1 + clk->clk_id); 253 } 254 255 static const struct clk_ops sci_clk_ops = { 256 .prepare = sci_clk_prepare, 257 .unprepare = sci_clk_unprepare, 258 .is_prepared = sci_clk_is_prepared, 259 .recalc_rate = sci_clk_recalc_rate, 260 .determine_rate = sci_clk_determine_rate, 261 .set_rate = sci_clk_set_rate, 262 .get_parent = sci_clk_get_parent, 263 .set_parent = sci_clk_set_parent, 264 }; 265 266 /** 267 * _sci_clk_get - Gets a handle for an SCI clock 268 * @provider: Handle to SCI clock provider 269 * @sci_clk: Handle to the SCI clock to populate 270 * 271 * Gets a handle to an existing TI SCI hw clock, or builds a new clock 272 * entry and registers it with the common clock framework. Called from 273 * the common clock framework, when a corresponding of_clk_get call is 274 * executed, or recursively from itself when parsing parent clocks. 275 * Returns 0 on success, negative error code on failure. 276 */ 277 static int _sci_clk_build(struct sci_clk_provider *provider, 278 struct sci_clk *sci_clk) 279 { 280 struct clk_init_data init = { NULL }; 281 char *name = NULL; 282 char **parent_names = NULL; 283 int i; 284 int ret = 0; 285 286 name = kasprintf(GFP_KERNEL, "clk:%d:%d", sci_clk->dev_id, 287 sci_clk->clk_id); 288 289 init.name = name; 290 291 /* 292 * From kernel point of view, we only care about a clocks parents, 293 * if it has more than 1 possible parent. In this case, it is going 294 * to have mux functionality. Otherwise it is going to act as a root 295 * clock. 296 */ 297 if (sci_clk->num_parents < 2) 298 sci_clk->num_parents = 0; 299 300 if (sci_clk->num_parents) { 301 parent_names = kcalloc(sci_clk->num_parents, sizeof(char *), 302 GFP_KERNEL); 303 304 if (!parent_names) { 305 ret = -ENOMEM; 306 goto err; 307 } 308 309 for (i = 0; i < sci_clk->num_parents; i++) { 310 char *parent_name; 311 312 parent_name = kasprintf(GFP_KERNEL, "clk:%d:%d", 313 sci_clk->dev_id, 314 sci_clk->clk_id + 1 + i); 315 if (!parent_name) { 316 ret = -ENOMEM; 317 goto err; 318 } 319 parent_names[i] = parent_name; 320 } 321 init.parent_names = (void *)parent_names; 322 } 323 324 init.ops = &sci_clk_ops; 325 init.num_parents = sci_clk->num_parents; 326 sci_clk->hw.init = &init; 327 328 ret = devm_clk_hw_register(provider->dev, &sci_clk->hw); 329 if (ret) 330 dev_err(provider->dev, "failed clk register with %d\n", ret); 331 332 err: 333 if (parent_names) { 334 for (i = 0; i < sci_clk->num_parents; i++) 335 kfree(parent_names[i]); 336 337 kfree(parent_names); 338 } 339 340 kfree(name); 341 342 return ret; 343 } 344 345 static int _cmp_sci_clk(const void *a, const void *b) 346 { 347 const struct sci_clk *ca = a; 348 const struct sci_clk *cb = *(struct sci_clk **)b; 349 350 if (ca->dev_id == cb->dev_id && ca->clk_id == cb->clk_id) 351 return 0; 352 if (ca->dev_id > cb->dev_id || 353 (ca->dev_id == cb->dev_id && ca->clk_id > cb->clk_id)) 354 return 1; 355 return -1; 356 } 357 358 /** 359 * sci_clk_get - Xlate function for getting clock handles 360 * @clkspec: device tree clock specifier 361 * @data: pointer to the clock provider 362 * 363 * Xlate function for retrieving clock TI SCI hw clock handles based on 364 * device tree clock specifier. Called from the common clock framework, 365 * when a corresponding of_clk_get call is executed. Returns a pointer 366 * to the TI SCI hw clock struct, or ERR_PTR value in failure. 367 */ 368 static struct clk_hw *sci_clk_get(struct of_phandle_args *clkspec, void *data) 369 { 370 struct sci_clk_provider *provider = data; 371 struct sci_clk **clk; 372 struct sci_clk key; 373 374 if (clkspec->args_count != 2) 375 return ERR_PTR(-EINVAL); 376 377 key.dev_id = clkspec->args[0]; 378 key.clk_id = clkspec->args[1]; 379 380 clk = bsearch(&key, provider->clocks, provider->num_clocks, 381 sizeof(clk), _cmp_sci_clk); 382 383 if (!clk) 384 return ERR_PTR(-ENODEV); 385 386 return &(*clk)->hw; 387 } 388 389 static int ti_sci_init_clocks(struct sci_clk_provider *p) 390 { 391 int i; 392 int ret; 393 394 for (i = 0; i < p->num_clocks; i++) { 395 ret = _sci_clk_build(p, p->clocks[i]); 396 if (ret) 397 return ret; 398 } 399 400 return 0; 401 } 402 403 static const struct of_device_id ti_sci_clk_of_match[] = { 404 { .compatible = "ti,k2g-sci-clk" }, 405 { /* Sentinel */ }, 406 }; 407 MODULE_DEVICE_TABLE(of, ti_sci_clk_of_match); 408 409 #ifdef CONFIG_TI_SCI_CLK_PROBE_FROM_FW 410 static int ti_sci_scan_clocks_from_fw(struct sci_clk_provider *provider) 411 { 412 int ret; 413 int num_clks = 0; 414 struct sci_clk **clks = NULL; 415 struct sci_clk **tmp_clks; 416 struct sci_clk *sci_clk; 417 int max_clks = 0; 418 int clk_id = 0; 419 int dev_id = 0; 420 u8 num_parents; 421 int gap_size = 0; 422 struct device *dev = provider->dev; 423 424 while (1) { 425 ret = provider->ops->get_num_parents(provider->sci, dev_id, 426 clk_id, &num_parents); 427 if (ret) { 428 gap_size++; 429 if (!clk_id) { 430 if (gap_size >= 5) 431 break; 432 dev_id++; 433 } else { 434 if (gap_size >= 2) { 435 dev_id++; 436 clk_id = 0; 437 gap_size = 0; 438 } else { 439 clk_id++; 440 } 441 } 442 continue; 443 } 444 445 gap_size = 0; 446 447 if (num_clks == max_clks) { 448 tmp_clks = devm_kmalloc_array(dev, max_clks + 64, 449 sizeof(sci_clk), 450 GFP_KERNEL); 451 memcpy(tmp_clks, clks, max_clks * sizeof(sci_clk)); 452 if (max_clks) 453 devm_kfree(dev, clks); 454 max_clks += 64; 455 clks = tmp_clks; 456 } 457 458 sci_clk = devm_kzalloc(dev, sizeof(*sci_clk), GFP_KERNEL); 459 if (!sci_clk) 460 return -ENOMEM; 461 sci_clk->dev_id = dev_id; 462 sci_clk->clk_id = clk_id; 463 sci_clk->provider = provider; 464 sci_clk->num_parents = num_parents; 465 466 clks[num_clks] = sci_clk; 467 468 clk_id++; 469 num_clks++; 470 } 471 472 provider->clocks = devm_kmalloc_array(dev, num_clks, sizeof(sci_clk), 473 GFP_KERNEL); 474 if (!provider->clocks) 475 return -ENOMEM; 476 477 memcpy(provider->clocks, clks, num_clks * sizeof(sci_clk)); 478 479 provider->num_clocks = num_clks; 480 481 devm_kfree(dev, clks); 482 483 return 0; 484 } 485 486 #else 487 488 static int _cmp_sci_clk_list(void *priv, struct list_head *a, 489 struct list_head *b) 490 { 491 struct sci_clk *ca = container_of(a, struct sci_clk, node); 492 struct sci_clk *cb = container_of(b, struct sci_clk, node); 493 494 return _cmp_sci_clk(ca, &cb); 495 } 496 497 static int ti_sci_scan_clocks_from_dt(struct sci_clk_provider *provider) 498 { 499 struct device *dev = provider->dev; 500 struct device_node *np = NULL; 501 int ret; 502 int index; 503 struct of_phandle_args args; 504 struct list_head clks; 505 struct sci_clk *sci_clk, *prev; 506 int num_clks = 0; 507 int num_parents; 508 int clk_id; 509 const char * const clk_names[] = { 510 "clocks", "assigned-clocks", "assigned-clock-parents", NULL 511 }; 512 const char * const *clk_name; 513 514 INIT_LIST_HEAD(&clks); 515 516 clk_name = clk_names; 517 518 while (*clk_name) { 519 np = of_find_node_with_property(np, *clk_name); 520 if (!np) { 521 clk_name++; 522 break; 523 } 524 525 if (!of_device_is_available(np)) 526 continue; 527 528 index = 0; 529 530 do { 531 ret = of_parse_phandle_with_args(np, *clk_name, 532 "#clock-cells", index, 533 &args); 534 if (ret) 535 break; 536 537 if (args.args_count == 2 && args.np == dev->of_node) { 538 sci_clk = devm_kzalloc(dev, sizeof(*sci_clk), 539 GFP_KERNEL); 540 if (!sci_clk) 541 return -ENOMEM; 542 543 sci_clk->dev_id = args.args[0]; 544 sci_clk->clk_id = args.args[1]; 545 sci_clk->provider = provider; 546 provider->ops->get_num_parents(provider->sci, 547 sci_clk->dev_id, 548 sci_clk->clk_id, 549 &sci_clk->num_parents); 550 list_add_tail(&sci_clk->node, &clks); 551 552 num_clks++; 553 554 num_parents = sci_clk->num_parents; 555 if (num_parents == 1) 556 num_parents = 0; 557 558 clk_id = args.args[1] + 1; 559 560 while (num_parents--) { 561 sci_clk = devm_kzalloc(dev, 562 sizeof(*sci_clk), 563 GFP_KERNEL); 564 if (!sci_clk) 565 return -ENOMEM; 566 sci_clk->dev_id = args.args[0]; 567 sci_clk->clk_id = clk_id++; 568 sci_clk->provider = provider; 569 list_add_tail(&sci_clk->node, &clks); 570 571 num_clks++; 572 } 573 } 574 575 index++; 576 } while (args.np); 577 } 578 579 list_sort(NULL, &clks, _cmp_sci_clk_list); 580 581 provider->clocks = devm_kmalloc_array(dev, num_clks, sizeof(sci_clk), 582 GFP_KERNEL); 583 if (!provider->clocks) 584 return -ENOMEM; 585 586 num_clks = 0; 587 prev = NULL; 588 589 list_for_each_entry(sci_clk, &clks, node) { 590 if (prev && prev->dev_id == sci_clk->dev_id && 591 prev->clk_id == sci_clk->clk_id) 592 continue; 593 594 provider->clocks[num_clks++] = sci_clk; 595 prev = sci_clk; 596 } 597 598 provider->num_clocks = num_clks; 599 600 return 0; 601 } 602 #endif 603 604 /** 605 * ti_sci_clk_probe - Probe function for the TI SCI clock driver 606 * @pdev: platform device pointer to be probed 607 * 608 * Probes the TI SCI clock device. Allocates a new clock provider 609 * and registers this to the common clock framework. Also applies 610 * any required flags to the identified clocks via clock lists 611 * supplied from DT. Returns 0 for success, negative error value 612 * for failure. 613 */ 614 static int ti_sci_clk_probe(struct platform_device *pdev) 615 { 616 struct device *dev = &pdev->dev; 617 struct device_node *np = dev->of_node; 618 struct sci_clk_provider *provider; 619 const struct ti_sci_handle *handle; 620 int ret; 621 622 handle = devm_ti_sci_get_handle(dev); 623 if (IS_ERR(handle)) 624 return PTR_ERR(handle); 625 626 provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL); 627 if (!provider) 628 return -ENOMEM; 629 630 provider->sci = handle; 631 provider->ops = &handle->ops.clk_ops; 632 provider->dev = dev; 633 634 #ifdef CONFIG_TI_SCI_CLK_PROBE_FROM_FW 635 ret = ti_sci_scan_clocks_from_fw(provider); 636 if (ret) { 637 dev_err(dev, "scan clocks from FW failed: %d\n", ret); 638 return ret; 639 } 640 #else 641 ret = ti_sci_scan_clocks_from_dt(provider); 642 if (ret) { 643 dev_err(dev, "scan clocks from DT failed: %d\n", ret); 644 return ret; 645 } 646 #endif 647 648 ret = ti_sci_init_clocks(provider); 649 if (ret) { 650 pr_err("ti-sci-init-clocks failed.\n"); 651 return ret; 652 } 653 654 return of_clk_add_hw_provider(np, sci_clk_get, provider); 655 } 656 657 /** 658 * ti_sci_clk_remove - Remove TI SCI clock device 659 * @pdev: platform device pointer for the device to be removed 660 * 661 * Removes the TI SCI device. Unregisters the clock provider registered 662 * via common clock framework. Any memory allocated for the device will 663 * be free'd silently via the devm framework. Returns 0 always. 664 */ 665 static int ti_sci_clk_remove(struct platform_device *pdev) 666 { 667 of_clk_del_provider(pdev->dev.of_node); 668 669 return 0; 670 } 671 672 static struct platform_driver ti_sci_clk_driver = { 673 .probe = ti_sci_clk_probe, 674 .remove = ti_sci_clk_remove, 675 .driver = { 676 .name = "ti-sci-clk", 677 .of_match_table = of_match_ptr(ti_sci_clk_of_match), 678 }, 679 }; 680 module_platform_driver(ti_sci_clk_driver); 681 682 MODULE_LICENSE("GPL v2"); 683 MODULE_DESCRIPTION("TI System Control Interface(SCI) Clock driver"); 684 MODULE_AUTHOR("Tero Kristo"); 685 MODULE_ALIAS("platform:ti-sci-clk"); 686