1 /* 2 * Core driver for the pin muxing portions of the pin control subsystem 3 * 4 * Copyright (C) 2011-2012 ST-Ericsson SA 5 * Written on behalf of Linaro for ST-Ericsson 6 * Based on bits of regulator core, gpio core and clk core 7 * 8 * Author: Linus Walleij <linus.walleij@linaro.org> 9 * 10 * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved. 11 * 12 * License terms: GNU General Public License (GPL) version 2 13 */ 14 #define pr_fmt(fmt) "pinmux core: " fmt 15 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/init.h> 19 #include <linux/device.h> 20 #include <linux/slab.h> 21 #include <linux/radix-tree.h> 22 #include <linux/err.h> 23 #include <linux/list.h> 24 #include <linux/string.h> 25 #include <linux/sysfs.h> 26 #include <linux/debugfs.h> 27 #include <linux/seq_file.h> 28 #include <linux/pinctrl/machine.h> 29 #include <linux/pinctrl/pinmux.h> 30 #include "core.h" 31 #include "pinmux.h" 32 33 int pinmux_check_ops(struct pinctrl_dev *pctldev) 34 { 35 const struct pinmux_ops *ops = pctldev->desc->pmxops; 36 unsigned nfuncs; 37 unsigned selector = 0; 38 39 /* Check that we implement required operations */ 40 if (!ops || 41 !ops->get_functions_count || 42 !ops->get_function_name || 43 !ops->get_function_groups || 44 !ops->set_mux) { 45 dev_err(pctldev->dev, "pinmux ops lacks necessary functions\n"); 46 return -EINVAL; 47 } 48 /* Check that all functions registered have names */ 49 nfuncs = ops->get_functions_count(pctldev); 50 while (selector < nfuncs) { 51 const char *fname = ops->get_function_name(pctldev, 52 selector); 53 if (!fname) { 54 dev_err(pctldev->dev, "pinmux ops has no name for function%u\n", 55 selector); 56 return -EINVAL; 57 } 58 selector++; 59 } 60 61 return 0; 62 } 63 64 int pinmux_validate_map(struct pinctrl_map const *map, int i) 65 { 66 if (!map->data.mux.function) { 67 pr_err("failed to register map %s (%d): no function given\n", 68 map->name, i); 69 return -EINVAL; 70 } 71 72 return 0; 73 } 74 75 /** 76 * pin_request() - request a single pin to be muxed in, typically for GPIO 77 * @pin: the pin number in the global pin space 78 * @owner: a representation of the owner of this pin; typically the device 79 * name that controls its mux function, or the requested GPIO name 80 * @gpio_range: the range matching the GPIO pin if this is a request for a 81 * single GPIO pin 82 */ 83 static int pin_request(struct pinctrl_dev *pctldev, 84 int pin, const char *owner, 85 struct pinctrl_gpio_range *gpio_range) 86 { 87 struct pin_desc *desc; 88 const struct pinmux_ops *ops = pctldev->desc->pmxops; 89 int status = -EINVAL; 90 91 desc = pin_desc_get(pctldev, pin); 92 if (desc == NULL) { 93 dev_err(pctldev->dev, 94 "pin %d is not registered so it cannot be requested\n", 95 pin); 96 goto out; 97 } 98 99 dev_dbg(pctldev->dev, "request pin %d (%s) for %s\n", 100 pin, desc->name, owner); 101 102 if (gpio_range) { 103 /* There's no need to support multiple GPIO requests */ 104 if (desc->gpio_owner) { 105 dev_err(pctldev->dev, 106 "pin %s already requested by %s; cannot claim for %s\n", 107 desc->name, desc->gpio_owner, owner); 108 goto out; 109 } 110 if (ops->strict && desc->mux_usecount && 111 strcmp(desc->mux_owner, owner)) { 112 dev_err(pctldev->dev, 113 "pin %s already requested by %s; cannot claim for %s\n", 114 desc->name, desc->mux_owner, owner); 115 goto out; 116 } 117 118 desc->gpio_owner = owner; 119 } else { 120 if (desc->mux_usecount && strcmp(desc->mux_owner, owner)) { 121 dev_err(pctldev->dev, 122 "pin %s already requested by %s; cannot claim for %s\n", 123 desc->name, desc->mux_owner, owner); 124 goto out; 125 } 126 if (ops->strict && desc->gpio_owner) { 127 dev_err(pctldev->dev, 128 "pin %s already requested by %s; cannot claim for %s\n", 129 desc->name, desc->gpio_owner, owner); 130 goto out; 131 } 132 133 desc->mux_usecount++; 134 if (desc->mux_usecount > 1) 135 return 0; 136 137 desc->mux_owner = owner; 138 } 139 140 /* Let each pin increase references to this module */ 141 if (!try_module_get(pctldev->owner)) { 142 dev_err(pctldev->dev, 143 "could not increase module refcount for pin %d\n", 144 pin); 145 status = -EINVAL; 146 goto out_free_pin; 147 } 148 149 /* 150 * If there is no kind of request function for the pin we just assume 151 * we got it by default and proceed. 152 */ 153 if (gpio_range && ops->gpio_request_enable) 154 /* This requests and enables a single GPIO pin */ 155 status = ops->gpio_request_enable(pctldev, gpio_range, pin); 156 else if (ops->request) 157 status = ops->request(pctldev, pin); 158 else 159 status = 0; 160 161 if (status) { 162 dev_err(pctldev->dev, "request() failed for pin %d\n", pin); 163 module_put(pctldev->owner); 164 } 165 166 out_free_pin: 167 if (status) { 168 if (gpio_range) { 169 desc->gpio_owner = NULL; 170 } else { 171 desc->mux_usecount--; 172 if (!desc->mux_usecount) 173 desc->mux_owner = NULL; 174 } 175 } 176 out: 177 if (status) 178 dev_err(pctldev->dev, "pin-%d (%s) status %d\n", 179 pin, owner, status); 180 181 return status; 182 } 183 184 /** 185 * pin_free() - release a single muxed in pin so something else can be muxed 186 * @pctldev: pin controller device handling this pin 187 * @pin: the pin to free 188 * @gpio_range: the range matching the GPIO pin if this is a request for a 189 * single GPIO pin 190 * 191 * This function returns a pointer to the previous owner. This is used 192 * for callers that dynamically allocate an owner name so it can be freed 193 * once the pin is free. This is done for GPIO request functions. 194 */ 195 static const char *pin_free(struct pinctrl_dev *pctldev, int pin, 196 struct pinctrl_gpio_range *gpio_range) 197 { 198 const struct pinmux_ops *ops = pctldev->desc->pmxops; 199 struct pin_desc *desc; 200 const char *owner; 201 202 desc = pin_desc_get(pctldev, pin); 203 if (desc == NULL) { 204 dev_err(pctldev->dev, 205 "pin is not registered so it cannot be freed\n"); 206 return NULL; 207 } 208 209 if (!gpio_range) { 210 /* 211 * A pin should not be freed more times than allocated. 212 */ 213 if (WARN_ON(!desc->mux_usecount)) 214 return NULL; 215 desc->mux_usecount--; 216 if (desc->mux_usecount) 217 return NULL; 218 } 219 220 /* 221 * If there is no kind of request function for the pin we just assume 222 * we got it by default and proceed. 223 */ 224 if (gpio_range && ops->gpio_disable_free) 225 ops->gpio_disable_free(pctldev, gpio_range, pin); 226 else if (ops->free) 227 ops->free(pctldev, pin); 228 229 if (gpio_range) { 230 owner = desc->gpio_owner; 231 desc->gpio_owner = NULL; 232 } else { 233 owner = desc->mux_owner; 234 desc->mux_owner = NULL; 235 desc->mux_setting = NULL; 236 } 237 238 module_put(pctldev->owner); 239 240 return owner; 241 } 242 243 /** 244 * pinmux_request_gpio() - request pinmuxing for a GPIO pin 245 * @pctldev: pin controller device affected 246 * @pin: the pin to mux in for GPIO 247 * @range: the applicable GPIO range 248 */ 249 int pinmux_request_gpio(struct pinctrl_dev *pctldev, 250 struct pinctrl_gpio_range *range, 251 unsigned pin, unsigned gpio) 252 { 253 const char *owner; 254 int ret; 255 256 /* Conjure some name stating what chip and pin this is taken by */ 257 owner = kasprintf(GFP_KERNEL, "%s:%d", range->name, gpio); 258 if (!owner) 259 return -EINVAL; 260 261 ret = pin_request(pctldev, pin, owner, range); 262 if (ret < 0) 263 kfree(owner); 264 265 return ret; 266 } 267 268 /** 269 * pinmux_free_gpio() - release a pin from GPIO muxing 270 * @pctldev: the pin controller device for the pin 271 * @pin: the affected currently GPIO-muxed in pin 272 * @range: applicable GPIO range 273 */ 274 void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin, 275 struct pinctrl_gpio_range *range) 276 { 277 const char *owner; 278 279 owner = pin_free(pctldev, pin, range); 280 kfree(owner); 281 } 282 283 /** 284 * pinmux_gpio_direction() - set the direction of a single muxed-in GPIO pin 285 * @pctldev: the pin controller handling this pin 286 * @range: applicable GPIO range 287 * @pin: the affected GPIO pin in this controller 288 * @input: true if we set the pin as input, false for output 289 */ 290 int pinmux_gpio_direction(struct pinctrl_dev *pctldev, 291 struct pinctrl_gpio_range *range, 292 unsigned pin, bool input) 293 { 294 const struct pinmux_ops *ops; 295 int ret; 296 297 ops = pctldev->desc->pmxops; 298 299 if (ops->gpio_set_direction) 300 ret = ops->gpio_set_direction(pctldev, range, pin, input); 301 else 302 ret = 0; 303 304 return ret; 305 } 306 307 static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev, 308 const char *function) 309 { 310 const struct pinmux_ops *ops = pctldev->desc->pmxops; 311 unsigned nfuncs = ops->get_functions_count(pctldev); 312 unsigned selector = 0; 313 314 /* See if this pctldev has this function */ 315 while (selector < nfuncs) { 316 const char *fname = ops->get_function_name(pctldev, 317 selector); 318 319 if (!strcmp(function, fname)) 320 return selector; 321 322 selector++; 323 } 324 325 pr_err("%s does not support function %s\n", 326 pinctrl_dev_get_name(pctldev), function); 327 return -EINVAL; 328 } 329 330 int pinmux_map_to_setting(struct pinctrl_map const *map, 331 struct pinctrl_setting *setting) 332 { 333 struct pinctrl_dev *pctldev = setting->pctldev; 334 const struct pinmux_ops *pmxops = pctldev->desc->pmxops; 335 char const * const *groups; 336 unsigned num_groups; 337 int ret; 338 const char *group; 339 int i; 340 341 if (!pmxops) { 342 dev_err(pctldev->dev, "does not support mux function\n"); 343 return -EINVAL; 344 } 345 346 ret = pinmux_func_name_to_selector(pctldev, map->data.mux.function); 347 if (ret < 0) { 348 dev_err(pctldev->dev, "invalid function %s in map table\n", 349 map->data.mux.function); 350 return ret; 351 } 352 setting->data.mux.func = ret; 353 354 ret = pmxops->get_function_groups(pctldev, setting->data.mux.func, 355 &groups, &num_groups); 356 if (ret < 0) { 357 dev_err(pctldev->dev, "can't query groups for function %s\n", 358 map->data.mux.function); 359 return ret; 360 } 361 if (!num_groups) { 362 dev_err(pctldev->dev, 363 "function %s can't be selected on any group\n", 364 map->data.mux.function); 365 return -EINVAL; 366 } 367 if (map->data.mux.group) { 368 bool found = false; 369 group = map->data.mux.group; 370 for (i = 0; i < num_groups; i++) { 371 if (!strcmp(group, groups[i])) { 372 found = true; 373 break; 374 } 375 } 376 if (!found) { 377 dev_err(pctldev->dev, 378 "invalid group \"%s\" for function \"%s\"\n", 379 group, map->data.mux.function); 380 return -EINVAL; 381 } 382 } else { 383 group = groups[0]; 384 } 385 386 ret = pinctrl_get_group_selector(pctldev, group); 387 if (ret < 0) { 388 dev_err(pctldev->dev, "invalid group %s in map table\n", 389 map->data.mux.group); 390 return ret; 391 } 392 setting->data.mux.group = ret; 393 394 return 0; 395 } 396 397 void pinmux_free_setting(struct pinctrl_setting const *setting) 398 { 399 /* This function is currently unused */ 400 } 401 402 int pinmux_enable_setting(struct pinctrl_setting const *setting) 403 { 404 struct pinctrl_dev *pctldev = setting->pctldev; 405 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; 406 const struct pinmux_ops *ops = pctldev->desc->pmxops; 407 int ret = 0; 408 const unsigned *pins = NULL; 409 unsigned num_pins = 0; 410 int i; 411 struct pin_desc *desc; 412 413 if (pctlops->get_group_pins) 414 ret = pctlops->get_group_pins(pctldev, setting->data.mux.group, 415 &pins, &num_pins); 416 417 if (ret) { 418 const char *gname; 419 420 /* errors only affect debug data, so just warn */ 421 gname = pctlops->get_group_name(pctldev, 422 setting->data.mux.group); 423 dev_warn(pctldev->dev, 424 "could not get pins for group %s\n", 425 gname); 426 num_pins = 0; 427 } 428 429 /* Try to allocate all pins in this group, one by one */ 430 for (i = 0; i < num_pins; i++) { 431 ret = pin_request(pctldev, pins[i], setting->dev_name, NULL); 432 if (ret) { 433 const char *gname; 434 const char *pname; 435 436 desc = pin_desc_get(pctldev, pins[i]); 437 pname = desc ? desc->name : "non-existing"; 438 gname = pctlops->get_group_name(pctldev, 439 setting->data.mux.group); 440 dev_err(pctldev->dev, 441 "could not request pin %d (%s) from group %s " 442 " on device %s\n", 443 pins[i], pname, gname, 444 pinctrl_dev_get_name(pctldev)); 445 goto err_pin_request; 446 } 447 } 448 449 /* Now that we have acquired the pins, encode the mux setting */ 450 for (i = 0; i < num_pins; i++) { 451 desc = pin_desc_get(pctldev, pins[i]); 452 if (desc == NULL) { 453 dev_warn(pctldev->dev, 454 "could not get pin desc for pin %d\n", 455 pins[i]); 456 continue; 457 } 458 desc->mux_setting = &(setting->data.mux); 459 } 460 461 ret = ops->set_mux(pctldev, setting->data.mux.func, 462 setting->data.mux.group); 463 464 if (ret) 465 goto err_set_mux; 466 467 return 0; 468 469 err_set_mux: 470 for (i = 0; i < num_pins; i++) { 471 desc = pin_desc_get(pctldev, pins[i]); 472 if (desc) 473 desc->mux_setting = NULL; 474 } 475 err_pin_request: 476 /* On error release all taken pins */ 477 while (--i >= 0) 478 pin_free(pctldev, pins[i], NULL); 479 480 return ret; 481 } 482 483 void pinmux_disable_setting(struct pinctrl_setting const *setting) 484 { 485 struct pinctrl_dev *pctldev = setting->pctldev; 486 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; 487 int ret = 0; 488 const unsigned *pins = NULL; 489 unsigned num_pins = 0; 490 int i; 491 struct pin_desc *desc; 492 493 if (pctlops->get_group_pins) 494 ret = pctlops->get_group_pins(pctldev, setting->data.mux.group, 495 &pins, &num_pins); 496 if (ret) { 497 const char *gname; 498 499 /* errors only affect debug data, so just warn */ 500 gname = pctlops->get_group_name(pctldev, 501 setting->data.mux.group); 502 dev_warn(pctldev->dev, 503 "could not get pins for group %s\n", 504 gname); 505 num_pins = 0; 506 } 507 508 /* Flag the descs that no setting is active */ 509 for (i = 0; i < num_pins; i++) { 510 desc = pin_desc_get(pctldev, pins[i]); 511 if (desc == NULL) { 512 dev_warn(pctldev->dev, 513 "could not get pin desc for pin %d\n", 514 pins[i]); 515 continue; 516 } 517 if (desc->mux_setting == &(setting->data.mux)) { 518 desc->mux_setting = NULL; 519 /* And release the pin */ 520 pin_free(pctldev, pins[i], NULL); 521 } else { 522 const char *gname; 523 524 gname = pctlops->get_group_name(pctldev, 525 setting->data.mux.group); 526 dev_warn(pctldev->dev, 527 "not freeing pin %d (%s) as part of " 528 "deactivating group %s - it is already " 529 "used for some other setting", 530 pins[i], desc->name, gname); 531 } 532 } 533 } 534 535 #ifdef CONFIG_DEBUG_FS 536 537 /* Called from pincontrol core */ 538 static int pinmux_functions_show(struct seq_file *s, void *what) 539 { 540 struct pinctrl_dev *pctldev = s->private; 541 const struct pinmux_ops *pmxops = pctldev->desc->pmxops; 542 unsigned nfuncs; 543 unsigned func_selector = 0; 544 545 if (!pmxops) 546 return 0; 547 548 mutex_lock(&pctldev->mutex); 549 nfuncs = pmxops->get_functions_count(pctldev); 550 while (func_selector < nfuncs) { 551 const char *func = pmxops->get_function_name(pctldev, 552 func_selector); 553 const char * const *groups; 554 unsigned num_groups; 555 int ret; 556 int i; 557 558 ret = pmxops->get_function_groups(pctldev, func_selector, 559 &groups, &num_groups); 560 if (ret) { 561 seq_printf(s, "function %s: COULD NOT GET GROUPS\n", 562 func); 563 func_selector++; 564 continue; 565 } 566 567 seq_printf(s, "function: %s, groups = [ ", func); 568 for (i = 0; i < num_groups; i++) 569 seq_printf(s, "%s ", groups[i]); 570 seq_puts(s, "]\n"); 571 572 func_selector++; 573 } 574 575 mutex_unlock(&pctldev->mutex); 576 577 return 0; 578 } 579 580 static int pinmux_pins_show(struct seq_file *s, void *what) 581 { 582 struct pinctrl_dev *pctldev = s->private; 583 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; 584 const struct pinmux_ops *pmxops = pctldev->desc->pmxops; 585 unsigned i, pin; 586 587 if (!pmxops) 588 return 0; 589 590 seq_puts(s, "Pinmux settings per pin\n"); 591 if (pmxops->strict) 592 seq_puts(s, 593 "Format: pin (name): mux_owner|gpio_owner (strict) hog?\n"); 594 else 595 seq_puts(s, 596 "Format: pin (name): mux_owner gpio_owner hog?\n"); 597 598 mutex_lock(&pctldev->mutex); 599 600 /* The pin number can be retrived from the pin controller descriptor */ 601 for (i = 0; i < pctldev->desc->npins; i++) { 602 struct pin_desc *desc; 603 bool is_hog = false; 604 605 pin = pctldev->desc->pins[i].number; 606 desc = pin_desc_get(pctldev, pin); 607 /* Skip if we cannot search the pin */ 608 if (desc == NULL) 609 continue; 610 611 if (desc->mux_owner && 612 !strcmp(desc->mux_owner, pinctrl_dev_get_name(pctldev))) 613 is_hog = true; 614 615 if (pmxops->strict) { 616 if (desc->mux_owner) 617 seq_printf(s, "pin %d (%s): device %s%s", 618 pin, 619 desc->name ? desc->name : "unnamed", 620 desc->mux_owner, 621 is_hog ? " (HOG)" : ""); 622 else if (desc->gpio_owner) 623 seq_printf(s, "pin %d (%s): GPIO %s", 624 pin, 625 desc->name ? desc->name : "unnamed", 626 desc->gpio_owner); 627 else 628 seq_printf(s, "pin %d (%s): UNCLAIMED", 629 pin, 630 desc->name ? desc->name : "unnamed"); 631 } else { 632 /* For non-strict controllers */ 633 seq_printf(s, "pin %d (%s): %s %s%s", pin, 634 desc->name ? desc->name : "unnamed", 635 desc->mux_owner ? desc->mux_owner 636 : "(MUX UNCLAIMED)", 637 desc->gpio_owner ? desc->gpio_owner 638 : "(GPIO UNCLAIMED)", 639 is_hog ? " (HOG)" : ""); 640 } 641 642 /* If mux: print function+group claiming the pin */ 643 if (desc->mux_setting) 644 seq_printf(s, " function %s group %s\n", 645 pmxops->get_function_name(pctldev, 646 desc->mux_setting->func), 647 pctlops->get_group_name(pctldev, 648 desc->mux_setting->group)); 649 else 650 seq_printf(s, "\n"); 651 } 652 653 mutex_unlock(&pctldev->mutex); 654 655 return 0; 656 } 657 658 void pinmux_show_map(struct seq_file *s, struct pinctrl_map const *map) 659 { 660 seq_printf(s, "group %s\nfunction %s\n", 661 map->data.mux.group ? map->data.mux.group : "(default)", 662 map->data.mux.function); 663 } 664 665 void pinmux_show_setting(struct seq_file *s, 666 struct pinctrl_setting const *setting) 667 { 668 struct pinctrl_dev *pctldev = setting->pctldev; 669 const struct pinmux_ops *pmxops = pctldev->desc->pmxops; 670 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; 671 672 seq_printf(s, "group: %s (%u) function: %s (%u)\n", 673 pctlops->get_group_name(pctldev, setting->data.mux.group), 674 setting->data.mux.group, 675 pmxops->get_function_name(pctldev, setting->data.mux.func), 676 setting->data.mux.func); 677 } 678 679 static int pinmux_functions_open(struct inode *inode, struct file *file) 680 { 681 return single_open(file, pinmux_functions_show, inode->i_private); 682 } 683 684 static int pinmux_pins_open(struct inode *inode, struct file *file) 685 { 686 return single_open(file, pinmux_pins_show, inode->i_private); 687 } 688 689 static const struct file_operations pinmux_functions_ops = { 690 .open = pinmux_functions_open, 691 .read = seq_read, 692 .llseek = seq_lseek, 693 .release = single_release, 694 }; 695 696 static const struct file_operations pinmux_pins_ops = { 697 .open = pinmux_pins_open, 698 .read = seq_read, 699 .llseek = seq_lseek, 700 .release = single_release, 701 }; 702 703 void pinmux_init_device_debugfs(struct dentry *devroot, 704 struct pinctrl_dev *pctldev) 705 { 706 debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO, 707 devroot, pctldev, &pinmux_functions_ops); 708 debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO, 709 devroot, pctldev, &pinmux_pins_ops); 710 } 711 712 #endif /* CONFIG_DEBUG_FS */ 713