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 -ENOMEM; 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, selector); 317 318 if (!strcmp(function, fname)) 319 return selector; 320 321 selector++; 322 } 323 324 dev_err(pctldev->dev, "function '%s' not supported\n", function); 325 return -EINVAL; 326 } 327 328 int pinmux_map_to_setting(struct pinctrl_map const *map, 329 struct pinctrl_setting *setting) 330 { 331 struct pinctrl_dev *pctldev = setting->pctldev; 332 const struct pinmux_ops *pmxops = pctldev->desc->pmxops; 333 char const * const *groups; 334 unsigned num_groups; 335 int ret; 336 const char *group; 337 338 if (!pmxops) { 339 dev_err(pctldev->dev, "does not support mux function\n"); 340 return -EINVAL; 341 } 342 343 ret = pinmux_func_name_to_selector(pctldev, map->data.mux.function); 344 if (ret < 0) { 345 dev_err(pctldev->dev, "invalid function %s in map table\n", 346 map->data.mux.function); 347 return ret; 348 } 349 setting->data.mux.func = ret; 350 351 ret = pmxops->get_function_groups(pctldev, setting->data.mux.func, 352 &groups, &num_groups); 353 if (ret < 0) { 354 dev_err(pctldev->dev, "can't query groups for function %s\n", 355 map->data.mux.function); 356 return ret; 357 } 358 if (!num_groups) { 359 dev_err(pctldev->dev, 360 "function %s can't be selected on any group\n", 361 map->data.mux.function); 362 return -EINVAL; 363 } 364 if (map->data.mux.group) { 365 group = map->data.mux.group; 366 ret = match_string(groups, num_groups, group); 367 if (ret < 0) { 368 dev_err(pctldev->dev, 369 "invalid group \"%s\" for function \"%s\"\n", 370 group, map->data.mux.function); 371 return ret; 372 } 373 } else { 374 group = groups[0]; 375 } 376 377 ret = pinctrl_get_group_selector(pctldev, group); 378 if (ret < 0) { 379 dev_err(pctldev->dev, "invalid group %s in map table\n", 380 map->data.mux.group); 381 return ret; 382 } 383 setting->data.mux.group = ret; 384 385 return 0; 386 } 387 388 void pinmux_free_setting(struct pinctrl_setting const *setting) 389 { 390 /* This function is currently unused */ 391 } 392 393 int pinmux_enable_setting(struct pinctrl_setting const *setting) 394 { 395 struct pinctrl_dev *pctldev = setting->pctldev; 396 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; 397 const struct pinmux_ops *ops = pctldev->desc->pmxops; 398 int ret = 0; 399 const unsigned *pins = NULL; 400 unsigned num_pins = 0; 401 int i; 402 struct pin_desc *desc; 403 404 if (pctlops->get_group_pins) 405 ret = pctlops->get_group_pins(pctldev, setting->data.mux.group, 406 &pins, &num_pins); 407 408 if (ret) { 409 const char *gname; 410 411 /* errors only affect debug data, so just warn */ 412 gname = pctlops->get_group_name(pctldev, 413 setting->data.mux.group); 414 dev_warn(pctldev->dev, 415 "could not get pins for group %s\n", 416 gname); 417 num_pins = 0; 418 } 419 420 /* Try to allocate all pins in this group, one by one */ 421 for (i = 0; i < num_pins; i++) { 422 ret = pin_request(pctldev, pins[i], setting->dev_name, NULL); 423 if (ret) { 424 const char *gname; 425 const char *pname; 426 427 desc = pin_desc_get(pctldev, pins[i]); 428 pname = desc ? desc->name : "non-existing"; 429 gname = pctlops->get_group_name(pctldev, 430 setting->data.mux.group); 431 dev_err(pctldev->dev, 432 "could not request pin %d (%s) from group %s " 433 " on device %s\n", 434 pins[i], pname, gname, 435 pinctrl_dev_get_name(pctldev)); 436 goto err_pin_request; 437 } 438 } 439 440 /* Now that we have acquired the pins, encode the mux setting */ 441 for (i = 0; i < num_pins; i++) { 442 desc = pin_desc_get(pctldev, pins[i]); 443 if (desc == NULL) { 444 dev_warn(pctldev->dev, 445 "could not get pin desc for pin %d\n", 446 pins[i]); 447 continue; 448 } 449 desc->mux_setting = &(setting->data.mux); 450 } 451 452 ret = ops->set_mux(pctldev, setting->data.mux.func, 453 setting->data.mux.group); 454 455 if (ret) 456 goto err_set_mux; 457 458 return 0; 459 460 err_set_mux: 461 for (i = 0; i < num_pins; i++) { 462 desc = pin_desc_get(pctldev, pins[i]); 463 if (desc) 464 desc->mux_setting = NULL; 465 } 466 err_pin_request: 467 /* On error release all taken pins */ 468 while (--i >= 0) 469 pin_free(pctldev, pins[i], NULL); 470 471 return ret; 472 } 473 474 void pinmux_disable_setting(struct pinctrl_setting const *setting) 475 { 476 struct pinctrl_dev *pctldev = setting->pctldev; 477 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; 478 int ret = 0; 479 const unsigned *pins = NULL; 480 unsigned num_pins = 0; 481 int i; 482 struct pin_desc *desc; 483 484 if (pctlops->get_group_pins) 485 ret = pctlops->get_group_pins(pctldev, setting->data.mux.group, 486 &pins, &num_pins); 487 if (ret) { 488 const char *gname; 489 490 /* errors only affect debug data, so just warn */ 491 gname = pctlops->get_group_name(pctldev, 492 setting->data.mux.group); 493 dev_warn(pctldev->dev, 494 "could not get pins for group %s\n", 495 gname); 496 num_pins = 0; 497 } 498 499 /* Flag the descs that no setting is active */ 500 for (i = 0; i < num_pins; i++) { 501 desc = pin_desc_get(pctldev, pins[i]); 502 if (desc == NULL) { 503 dev_warn(pctldev->dev, 504 "could not get pin desc for pin %d\n", 505 pins[i]); 506 continue; 507 } 508 if (desc->mux_setting == &(setting->data.mux)) { 509 desc->mux_setting = NULL; 510 /* And release the pin */ 511 pin_free(pctldev, pins[i], NULL); 512 } else { 513 const char *gname; 514 515 gname = pctlops->get_group_name(pctldev, 516 setting->data.mux.group); 517 dev_warn(pctldev->dev, 518 "not freeing pin %d (%s) as part of " 519 "deactivating group %s - it is already " 520 "used for some other setting", 521 pins[i], desc->name, gname); 522 } 523 } 524 } 525 526 #ifdef CONFIG_DEBUG_FS 527 528 /* Called from pincontrol core */ 529 static int pinmux_functions_show(struct seq_file *s, void *what) 530 { 531 struct pinctrl_dev *pctldev = s->private; 532 const struct pinmux_ops *pmxops = pctldev->desc->pmxops; 533 unsigned nfuncs; 534 unsigned func_selector = 0; 535 536 if (!pmxops) 537 return 0; 538 539 mutex_lock(&pctldev->mutex); 540 nfuncs = pmxops->get_functions_count(pctldev); 541 while (func_selector < nfuncs) { 542 const char *func = pmxops->get_function_name(pctldev, 543 func_selector); 544 const char * const *groups; 545 unsigned num_groups; 546 int ret; 547 int i; 548 549 ret = pmxops->get_function_groups(pctldev, func_selector, 550 &groups, &num_groups); 551 if (ret) { 552 seq_printf(s, "function %s: COULD NOT GET GROUPS\n", 553 func); 554 func_selector++; 555 continue; 556 } 557 558 seq_printf(s, "function: %s, groups = [ ", func); 559 for (i = 0; i < num_groups; i++) 560 seq_printf(s, "%s ", groups[i]); 561 seq_puts(s, "]\n"); 562 563 func_selector++; 564 } 565 566 mutex_unlock(&pctldev->mutex); 567 568 return 0; 569 } 570 571 static int pinmux_pins_show(struct seq_file *s, void *what) 572 { 573 struct pinctrl_dev *pctldev = s->private; 574 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; 575 const struct pinmux_ops *pmxops = pctldev->desc->pmxops; 576 unsigned i, pin; 577 578 if (!pmxops) 579 return 0; 580 581 seq_puts(s, "Pinmux settings per pin\n"); 582 if (pmxops->strict) 583 seq_puts(s, 584 "Format: pin (name): mux_owner|gpio_owner (strict) hog?\n"); 585 else 586 seq_puts(s, 587 "Format: pin (name): mux_owner gpio_owner hog?\n"); 588 589 mutex_lock(&pctldev->mutex); 590 591 /* The pin number can be retrived from the pin controller descriptor */ 592 for (i = 0; i < pctldev->desc->npins; i++) { 593 struct pin_desc *desc; 594 bool is_hog = false; 595 596 pin = pctldev->desc->pins[i].number; 597 desc = pin_desc_get(pctldev, pin); 598 /* Skip if we cannot search the pin */ 599 if (desc == NULL) 600 continue; 601 602 if (desc->mux_owner && 603 !strcmp(desc->mux_owner, pinctrl_dev_get_name(pctldev))) 604 is_hog = true; 605 606 if (pmxops->strict) { 607 if (desc->mux_owner) 608 seq_printf(s, "pin %d (%s): device %s%s", 609 pin, desc->name, desc->mux_owner, 610 is_hog ? " (HOG)" : ""); 611 else if (desc->gpio_owner) 612 seq_printf(s, "pin %d (%s): GPIO %s", 613 pin, desc->name, desc->gpio_owner); 614 else 615 seq_printf(s, "pin %d (%s): UNCLAIMED", 616 pin, desc->name); 617 } else { 618 /* For non-strict controllers */ 619 seq_printf(s, "pin %d (%s): %s %s%s", pin, desc->name, 620 desc->mux_owner ? desc->mux_owner 621 : "(MUX UNCLAIMED)", 622 desc->gpio_owner ? desc->gpio_owner 623 : "(GPIO UNCLAIMED)", 624 is_hog ? " (HOG)" : ""); 625 } 626 627 /* If mux: print function+group claiming the pin */ 628 if (desc->mux_setting) 629 seq_printf(s, " function %s group %s\n", 630 pmxops->get_function_name(pctldev, 631 desc->mux_setting->func), 632 pctlops->get_group_name(pctldev, 633 desc->mux_setting->group)); 634 else 635 seq_printf(s, "\n"); 636 } 637 638 mutex_unlock(&pctldev->mutex); 639 640 return 0; 641 } 642 643 void pinmux_show_map(struct seq_file *s, struct pinctrl_map const *map) 644 { 645 seq_printf(s, "group %s\nfunction %s\n", 646 map->data.mux.group ? map->data.mux.group : "(default)", 647 map->data.mux.function); 648 } 649 650 void pinmux_show_setting(struct seq_file *s, 651 struct pinctrl_setting const *setting) 652 { 653 struct pinctrl_dev *pctldev = setting->pctldev; 654 const struct pinmux_ops *pmxops = pctldev->desc->pmxops; 655 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; 656 657 seq_printf(s, "group: %s (%u) function: %s (%u)\n", 658 pctlops->get_group_name(pctldev, setting->data.mux.group), 659 setting->data.mux.group, 660 pmxops->get_function_name(pctldev, setting->data.mux.func), 661 setting->data.mux.func); 662 } 663 664 static int pinmux_functions_open(struct inode *inode, struct file *file) 665 { 666 return single_open(file, pinmux_functions_show, inode->i_private); 667 } 668 669 static int pinmux_pins_open(struct inode *inode, struct file *file) 670 { 671 return single_open(file, pinmux_pins_show, inode->i_private); 672 } 673 674 static const struct file_operations pinmux_functions_ops = { 675 .open = pinmux_functions_open, 676 .read = seq_read, 677 .llseek = seq_lseek, 678 .release = single_release, 679 }; 680 681 static const struct file_operations pinmux_pins_ops = { 682 .open = pinmux_pins_open, 683 .read = seq_read, 684 .llseek = seq_lseek, 685 .release = single_release, 686 }; 687 688 void pinmux_init_device_debugfs(struct dentry *devroot, 689 struct pinctrl_dev *pctldev) 690 { 691 debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO, 692 devroot, pctldev, &pinmux_functions_ops); 693 debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO, 694 devroot, pctldev, &pinmux_pins_ops); 695 } 696 697 #endif /* CONFIG_DEBUG_FS */ 698