1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2016 IBM Corp. 4 */ 5 6 #include <linux/mfd/syscon.h> 7 #include <linux/platform_device.h> 8 #include <linux/slab.h> 9 #include <linux/string.h> 10 #include "../core.h" 11 #include "pinctrl-aspeed.h" 12 13 int aspeed_pinctrl_get_groups_count(struct pinctrl_dev *pctldev) 14 { 15 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); 16 17 return pdata->pinmux.ngroups; 18 } 19 20 const char *aspeed_pinctrl_get_group_name(struct pinctrl_dev *pctldev, 21 unsigned int group) 22 { 23 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); 24 25 return pdata->pinmux.groups[group].name; 26 } 27 28 int aspeed_pinctrl_get_group_pins(struct pinctrl_dev *pctldev, 29 unsigned int group, const unsigned int **pins, 30 unsigned int *npins) 31 { 32 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); 33 34 *pins = &pdata->pinmux.groups[group].pins[0]; 35 *npins = pdata->pinmux.groups[group].npins; 36 37 return 0; 38 } 39 40 void aspeed_pinctrl_pin_dbg_show(struct pinctrl_dev *pctldev, 41 struct seq_file *s, unsigned int offset) 42 { 43 seq_printf(s, " %s", dev_name(pctldev->dev)); 44 } 45 46 int aspeed_pinmux_get_fn_count(struct pinctrl_dev *pctldev) 47 { 48 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); 49 50 return pdata->pinmux.nfunctions; 51 } 52 53 const char *aspeed_pinmux_get_fn_name(struct pinctrl_dev *pctldev, 54 unsigned int function) 55 { 56 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); 57 58 return pdata->pinmux.functions[function].name; 59 } 60 61 int aspeed_pinmux_get_fn_groups(struct pinctrl_dev *pctldev, 62 unsigned int function, 63 const char * const **groups, 64 unsigned int * const num_groups) 65 { 66 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); 67 68 *groups = pdata->pinmux.functions[function].groups; 69 *num_groups = pdata->pinmux.functions[function].ngroups; 70 71 return 0; 72 } 73 74 static int aspeed_sig_expr_enable(struct aspeed_pinmux_data *ctx, 75 const struct aspeed_sig_expr *expr) 76 { 77 int ret; 78 79 pr_debug("Enabling signal %s for %s\n", expr->signal, 80 expr->function); 81 82 ret = aspeed_sig_expr_eval(ctx, expr, true); 83 if (ret < 0) 84 return ret; 85 86 if (!ret) 87 return aspeed_sig_expr_set(ctx, expr, true); 88 89 return 0; 90 } 91 92 static int aspeed_sig_expr_disable(struct aspeed_pinmux_data *ctx, 93 const struct aspeed_sig_expr *expr) 94 { 95 int ret; 96 97 pr_debug("Disabling signal %s for %s\n", expr->signal, 98 expr->function); 99 100 ret = aspeed_sig_expr_eval(ctx, expr, true); 101 if (ret < 0) 102 return ret; 103 104 if (ret) 105 return aspeed_sig_expr_set(ctx, expr, false); 106 107 return 0; 108 } 109 110 /** 111 * aspeed_disable_sig() - Disable a signal on a pin by disabling all provided 112 * signal expressions. 113 * 114 * @ctx: The pinmux context 115 * @exprs: The list of signal expressions (from a priority level on a pin) 116 * 117 * Return: 0 if all expressions are disabled, otherwise a negative error code 118 */ 119 static int aspeed_disable_sig(struct aspeed_pinmux_data *ctx, 120 const struct aspeed_sig_expr **exprs) 121 { 122 int ret = 0; 123 124 if (!exprs) 125 return true; 126 127 while (*exprs && !ret) { 128 ret = aspeed_sig_expr_disable(ctx, *exprs); 129 exprs++; 130 } 131 132 return ret; 133 } 134 135 /** 136 * Search for the signal expression needed to enable the pin's signal for the 137 * requested function. 138 * 139 * @exprs: List of signal expressions (haystack) 140 * @name: The name of the requested function (needle) 141 * 142 * Return: A pointer to the signal expression whose function tag matches the 143 * provided name, otherwise NULL. 144 * 145 */ 146 static const struct aspeed_sig_expr *aspeed_find_expr_by_name( 147 const struct aspeed_sig_expr **exprs, const char *name) 148 { 149 while (*exprs) { 150 if (strcmp((*exprs)->function, name) == 0) 151 return *exprs; 152 exprs++; 153 } 154 155 return NULL; 156 } 157 158 static char *get_defined_attribute(const struct aspeed_pin_desc *pdesc, 159 const char *(*get)( 160 const struct aspeed_sig_expr *)) 161 { 162 char *found = NULL; 163 size_t len = 0; 164 const struct aspeed_sig_expr ***prios, **funcs, *expr; 165 166 prios = pdesc->prios; 167 168 while ((funcs = *prios)) { 169 while ((expr = *funcs)) { 170 const char *str = get(expr); 171 size_t delta = strlen(str) + 2; 172 char *expanded; 173 174 expanded = krealloc(found, len + delta + 1, GFP_KERNEL); 175 if (!expanded) { 176 kfree(found); 177 return expanded; 178 } 179 180 found = expanded; 181 found[len] = '\0'; 182 len += delta; 183 184 strcat(found, str); 185 strcat(found, ", "); 186 187 funcs++; 188 } 189 prios++; 190 } 191 192 if (len < 2) { 193 kfree(found); 194 return NULL; 195 } 196 197 found[len - 2] = '\0'; 198 199 return found; 200 } 201 202 static const char *aspeed_sig_expr_function(const struct aspeed_sig_expr *expr) 203 { 204 return expr->function; 205 } 206 207 static char *get_defined_functions(const struct aspeed_pin_desc *pdesc) 208 { 209 return get_defined_attribute(pdesc, aspeed_sig_expr_function); 210 } 211 212 static const char *aspeed_sig_expr_signal(const struct aspeed_sig_expr *expr) 213 { 214 return expr->signal; 215 } 216 217 static char *get_defined_signals(const struct aspeed_pin_desc *pdesc) 218 { 219 return get_defined_attribute(pdesc, aspeed_sig_expr_signal); 220 } 221 222 int aspeed_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int function, 223 unsigned int group) 224 { 225 int i; 226 int ret; 227 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); 228 const struct aspeed_pin_group *pgroup = &pdata->pinmux.groups[group]; 229 const struct aspeed_pin_function *pfunc = 230 &pdata->pinmux.functions[function]; 231 232 for (i = 0; i < pgroup->npins; i++) { 233 int pin = pgroup->pins[i]; 234 const struct aspeed_pin_desc *pdesc = pdata->pins[pin].drv_data; 235 const struct aspeed_sig_expr *expr = NULL; 236 const struct aspeed_sig_expr **funcs; 237 const struct aspeed_sig_expr ***prios; 238 239 pr_debug("Muxing pin %s for %s\n", pdesc->name, pfunc->name); 240 241 if (!pdesc) 242 return -EINVAL; 243 244 prios = pdesc->prios; 245 246 if (!prios) 247 continue; 248 249 /* Disable functions at a higher priority than that requested */ 250 while ((funcs = *prios)) { 251 expr = aspeed_find_expr_by_name(funcs, pfunc->name); 252 253 if (expr) 254 break; 255 256 ret = aspeed_disable_sig(&pdata->pinmux, funcs); 257 if (ret) 258 return ret; 259 260 prios++; 261 } 262 263 if (!expr) { 264 char *functions = get_defined_functions(pdesc); 265 char *signals = get_defined_signals(pdesc); 266 267 pr_warn("No function %s found on pin %s (%d). Found signal(s) %s for function(s) %s\n", 268 pfunc->name, pdesc->name, pin, signals, 269 functions); 270 kfree(signals); 271 kfree(functions); 272 273 return -ENXIO; 274 } 275 276 ret = aspeed_sig_expr_enable(&pdata->pinmux, expr); 277 if (ret) 278 return ret; 279 280 pr_debug("Muxed pin %s as %s for %s\n", pdesc->name, expr->signal, 281 expr->function); 282 } 283 284 return 0; 285 } 286 287 static bool aspeed_expr_is_gpio(const struct aspeed_sig_expr *expr) 288 { 289 /* 290 * We need to differentiate between GPIO and non-GPIO signals to 291 * implement the gpio_request_enable() interface. For better or worse 292 * the ASPEED pinctrl driver uses the expression names to determine 293 * whether an expression will mux a pin for GPIO. 294 * 295 * Generally we have the following - A GPIO such as B1 has: 296 * 297 * - expr->signal set to "GPIOB1" 298 * - expr->function set to "GPIOB1" 299 * 300 * Using this fact we can determine whether the provided expression is 301 * a GPIO expression by testing the signal name for the string prefix 302 * "GPIO". 303 * 304 * However, some GPIOs are input-only, and the ASPEED datasheets name 305 * them differently. An input-only GPIO such as T0 has: 306 * 307 * - expr->signal set to "GPIT0" 308 * - expr->function set to "GPIT0" 309 * 310 * It's tempting to generalise the prefix test from "GPIO" to "GPI" to 311 * account for both GPIOs and GPIs, but in doing so we run aground on 312 * another feature: 313 * 314 * Some pins in the ASPEED BMC SoCs have a "pass-through" GPIO 315 * function where the input state of one pin is replicated as the 316 * output state of another (as if they were shorted together - a mux 317 * configuration that is typically enabled by hardware strapping). 318 * This feature allows the BMC to pass e.g. power button state through 319 * to the host while the BMC is yet to boot, but take control of the 320 * button state once the BMC has booted by muxing each pin as a 321 * separate, pin-specific GPIO. 322 * 323 * Conceptually this pass-through mode is a form of GPIO and is named 324 * as such in the datasheets, e.g. "GPID0". This naming similarity 325 * trips us up with the simple GPI-prefixed-signal-name scheme 326 * discussed above, as the pass-through configuration is not what we 327 * want when muxing a pin as GPIO for the GPIO subsystem. 328 * 329 * On e.g. the AST2400, a pass-through function "GPID0" is grouped on 330 * balls A18 and D16, where we have: 331 * 332 * For ball A18: 333 * - expr->signal set to "GPID0IN" 334 * - expr->function set to "GPID0" 335 * 336 * For ball D16: 337 * - expr->signal set to "GPID0OUT" 338 * - expr->function set to "GPID0" 339 * 340 * By contrast, the pin-specific GPIO expressions for the same pins are 341 * as follows: 342 * 343 * For ball A18: 344 * - expr->signal looks like "GPIOD0" 345 * - expr->function looks like "GPIOD0" 346 * 347 * For ball D16: 348 * - expr->signal looks like "GPIOD1" 349 * - expr->function looks like "GPIOD1" 350 * 351 * Testing both the signal _and_ function names gives us the means 352 * differentiate the pass-through GPIO pinmux configuration from the 353 * pin-specific configuration that the GPIO subsystem is after: An 354 * expression is a pin-specific (non-pass-through) GPIO configuration 355 * if the signal prefix is "GPI" and the signal name matches the 356 * function name. 357 */ 358 return !strncmp(expr->signal, "GPI", 3) && 359 !strcmp(expr->signal, expr->function); 360 } 361 362 static bool aspeed_gpio_in_exprs(const struct aspeed_sig_expr **exprs) 363 { 364 if (!exprs) 365 return false; 366 367 while (*exprs) { 368 if (aspeed_expr_is_gpio(*exprs)) 369 return true; 370 exprs++; 371 } 372 373 return false; 374 } 375 376 int aspeed_gpio_request_enable(struct pinctrl_dev *pctldev, 377 struct pinctrl_gpio_range *range, 378 unsigned int offset) 379 { 380 int ret; 381 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); 382 const struct aspeed_pin_desc *pdesc = pdata->pins[offset].drv_data; 383 const struct aspeed_sig_expr ***prios, **funcs, *expr; 384 385 if (!pdesc) 386 return -EINVAL; 387 388 prios = pdesc->prios; 389 390 if (!prios) 391 return -ENXIO; 392 393 pr_debug("Muxing pin %s for GPIO\n", pdesc->name); 394 395 /* Disable any functions of higher priority than GPIO */ 396 while ((funcs = *prios)) { 397 if (aspeed_gpio_in_exprs(funcs)) 398 break; 399 400 ret = aspeed_disable_sig(&pdata->pinmux, funcs); 401 if (ret) 402 return ret; 403 404 prios++; 405 } 406 407 if (!funcs) { 408 char *signals = get_defined_signals(pdesc); 409 410 pr_warn("No GPIO signal type found on pin %s (%d). Found: %s\n", 411 pdesc->name, offset, signals); 412 kfree(signals); 413 414 return -ENXIO; 415 } 416 417 expr = *funcs; 418 419 /* 420 * Disabling all higher-priority expressions is enough to enable the 421 * lowest-priority signal type. As such it has no associated 422 * expression. 423 */ 424 if (!expr) { 425 pr_debug("Muxed pin %s as GPIO\n", pdesc->name); 426 return 0; 427 } 428 429 /* 430 * If GPIO is not the lowest priority signal type, assume there is only 431 * one expression defined to enable the GPIO function 432 */ 433 ret = aspeed_sig_expr_enable(&pdata->pinmux, expr); 434 if (ret) 435 return ret; 436 437 pr_debug("Muxed pin %s as %s\n", pdesc->name, expr->signal); 438 439 return 0; 440 } 441 442 int aspeed_pinctrl_probe(struct platform_device *pdev, 443 struct pinctrl_desc *pdesc, 444 struct aspeed_pinctrl_data *pdata) 445 { 446 struct device *parent; 447 struct pinctrl_dev *pctl; 448 449 parent = pdev->dev.parent; 450 if (!parent) { 451 dev_err(&pdev->dev, "No parent for syscon pincontroller\n"); 452 return -ENODEV; 453 } 454 455 pdata->scu = syscon_node_to_regmap(parent->of_node); 456 if (IS_ERR(pdata->scu)) { 457 dev_err(&pdev->dev, "No regmap for syscon pincontroller parent\n"); 458 return PTR_ERR(pdata->scu); 459 } 460 461 pdata->pinmux.maps[ASPEED_IP_SCU] = pdata->scu; 462 463 pctl = pinctrl_register(pdesc, &pdev->dev, pdata); 464 465 if (IS_ERR(pctl)) { 466 dev_err(&pdev->dev, "Failed to register pinctrl\n"); 467 return PTR_ERR(pctl); 468 } 469 470 platform_set_drvdata(pdev, pdata); 471 472 return 0; 473 } 474 475 static inline bool pin_in_config_range(unsigned int offset, 476 const struct aspeed_pin_config *config) 477 { 478 return offset >= config->pins[0] && offset <= config->pins[1]; 479 } 480 481 static inline const struct aspeed_pin_config *find_pinconf_config( 482 const struct aspeed_pinctrl_data *pdata, 483 unsigned int offset, 484 enum pin_config_param param) 485 { 486 unsigned int i; 487 488 for (i = 0; i < pdata->nconfigs; i++) { 489 if (param == pdata->configs[i].param && 490 pin_in_config_range(offset, &pdata->configs[i])) 491 return &pdata->configs[i]; 492 } 493 494 return NULL; 495 } 496 497 enum aspeed_pin_config_map_type { MAP_TYPE_ARG, MAP_TYPE_VAL }; 498 499 static const struct aspeed_pin_config_map *find_pinconf_map( 500 const struct aspeed_pinctrl_data *pdata, 501 enum pin_config_param param, 502 enum aspeed_pin_config_map_type type, 503 s64 value) 504 { 505 int i; 506 507 for (i = 0; i < pdata->nconfmaps; i++) { 508 const struct aspeed_pin_config_map *elem; 509 bool match; 510 511 elem = &pdata->confmaps[i]; 512 513 switch (type) { 514 case MAP_TYPE_ARG: 515 match = (elem->arg == -1 || elem->arg == value); 516 break; 517 case MAP_TYPE_VAL: 518 match = (elem->val == value); 519 break; 520 } 521 522 if (param == elem->param && match) 523 return elem; 524 } 525 526 return NULL; 527 } 528 529 int aspeed_pin_config_get(struct pinctrl_dev *pctldev, unsigned int offset, 530 unsigned long *config) 531 { 532 const enum pin_config_param param = pinconf_to_config_param(*config); 533 const struct aspeed_pin_config_map *pmap; 534 const struct aspeed_pinctrl_data *pdata; 535 const struct aspeed_pin_config *pconf; 536 unsigned int val; 537 int rc = 0; 538 u32 arg; 539 540 pdata = pinctrl_dev_get_drvdata(pctldev); 541 pconf = find_pinconf_config(pdata, offset, param); 542 if (!pconf) 543 return -ENOTSUPP; 544 545 rc = regmap_read(pdata->scu, pconf->reg, &val); 546 if (rc < 0) 547 return rc; 548 549 pmap = find_pinconf_map(pdata, param, MAP_TYPE_VAL, 550 (val & pconf->mask) >> __ffs(pconf->mask)); 551 552 if (!pmap) 553 return -EINVAL; 554 555 if (param == PIN_CONFIG_DRIVE_STRENGTH) 556 arg = (u32) pmap->arg; 557 else if (param == PIN_CONFIG_BIAS_PULL_DOWN) 558 arg = !!pmap->arg; 559 else 560 arg = 1; 561 562 if (!arg) 563 return -EINVAL; 564 565 *config = pinconf_to_config_packed(param, arg); 566 567 return 0; 568 } 569 570 int aspeed_pin_config_set(struct pinctrl_dev *pctldev, unsigned int offset, 571 unsigned long *configs, unsigned int num_configs) 572 { 573 const struct aspeed_pinctrl_data *pdata; 574 unsigned int i; 575 int rc = 0; 576 577 pdata = pinctrl_dev_get_drvdata(pctldev); 578 579 for (i = 0; i < num_configs; i++) { 580 const struct aspeed_pin_config_map *pmap; 581 const struct aspeed_pin_config *pconf; 582 enum pin_config_param param; 583 unsigned int val; 584 u32 arg; 585 586 param = pinconf_to_config_param(configs[i]); 587 arg = pinconf_to_config_argument(configs[i]); 588 589 pconf = find_pinconf_config(pdata, offset, param); 590 if (!pconf) 591 return -ENOTSUPP; 592 593 pmap = find_pinconf_map(pdata, param, MAP_TYPE_ARG, arg); 594 595 if (WARN_ON(!pmap)) 596 return -EINVAL; 597 598 val = pmap->val << __ffs(pconf->mask); 599 600 rc = regmap_update_bits(pdata->scu, pconf->reg, 601 pconf->mask, val); 602 603 if (rc < 0) 604 return rc; 605 606 pr_debug("%s: Set SCU%02X[0x%08X]=0x%X for param %d(=%d) on pin %d\n", 607 __func__, pconf->reg, pconf->mask, 608 val, param, arg, offset); 609 } 610 611 return 0; 612 } 613 614 int aspeed_pin_config_group_get(struct pinctrl_dev *pctldev, 615 unsigned int selector, 616 unsigned long *config) 617 { 618 const unsigned int *pins; 619 unsigned int npins; 620 int rc; 621 622 rc = aspeed_pinctrl_get_group_pins(pctldev, selector, &pins, &npins); 623 if (rc < 0) 624 return rc; 625 626 if (!npins) 627 return -ENODEV; 628 629 rc = aspeed_pin_config_get(pctldev, pins[0], config); 630 631 return rc; 632 } 633 634 int aspeed_pin_config_group_set(struct pinctrl_dev *pctldev, 635 unsigned int selector, 636 unsigned long *configs, 637 unsigned int num_configs) 638 { 639 const unsigned int *pins; 640 unsigned int npins; 641 int rc; 642 int i; 643 644 pr_debug("%s: Fetching pins for group selector %d\n", 645 __func__, selector); 646 rc = aspeed_pinctrl_get_group_pins(pctldev, selector, &pins, &npins); 647 if (rc < 0) 648 return rc; 649 650 for (i = 0; i < npins; i++) { 651 rc = aspeed_pin_config_set(pctldev, pins[i], configs, 652 num_configs); 653 if (rc < 0) 654 return rc; 655 } 656 657 return 0; 658 } 659