drivers/pinctrl/pinconf.c

   1 /*
   2  * Core driver for the pin config portions of the pin control subsystem
   3  *
   4  * Copyright (C) 2011 ST-Ericsson SA
   5  * Written on behalf of Linaro for ST-Ericsson
   6  *
   7  * Author: Linus Walleij <linus.walleij@linaro.org>
   8  *
   9  * License terms: GNU General Public License (GPL) version 2
  10  */
  11 #define pr_fmt(fmt) "pinconfig core: " fmt
  12
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/device.h>
  17 #include <linux/slab.h>
  18 #include <linux/debugfs.h>
  19 #include <linux/seq_file.h>
  20 #include <linux/uaccess.h>
  21 #include <linux/pinctrl/machine.h>
  22 #include <linux/pinctrl/pinctrl.h>
  23 #include <linux/pinctrl/pinconf.h>
  24 #include "core.h"
  25 #include "pinconf.h"
  26
  27 int pinconf_check_ops(struct pinctrl_dev *pctldev)
  28 {
  29         const struct pinconf_ops *ops = pctldev->desc->confops;
  30
  31         /* We have to be able to config the pins in SOME way */
  32         if (!ops->pin_config_set && !ops->pin_config_group_set) {
  33                 dev_err(pctldev->dev,
  34                         "pinconf has to be able to set a pins config\n");
  35                 return -EINVAL;
  36         }
  37         return 0;
  38 }
  39
  40 int pinconf_validate_map(struct pinctrl_map const *map, int i)
  41 {
  42         if (!map->data.configs.group_or_pin) {
  43                 pr_err("failed to register map %s (%d): no group/pin given\n",
  44                        map->name, i);
  45                 return -EINVAL;
  46         }
  47
  48         if (!map->data.configs.num_configs ||
  49                         !map->data.configs.configs) {
  50                 pr_err("failed to register map %s (%d): no configs given\n",
  51                        map->name, i);
  52                 return -EINVAL;
  53         }
  54
  55         return 0;
  56 }
  57
  58 int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
  59                            unsigned long *config)
  60 {
  61         const struct pinconf_ops *ops = pctldev->desc->confops;
  62
  63         if (!ops || !ops->pin_config_get) {
  64                 dev_dbg(pctldev->dev,
  65                         "cannot get pin configuration, .pin_config_get missing in driver\n");
  66                 return -ENOTSUPP;
  67         }
  68
  69         return ops->pin_config_get(pctldev, pin, config);
  70 }
  71
  72 int pin_config_group_get(const char *dev_name, const char *pin_group,
  73                          unsigned long *config)
  74 {
  75         struct pinctrl_dev *pctldev;
  76         const struct pinconf_ops *ops;
  77         int selector, ret;
  78
  79         pctldev = get_pinctrl_dev_from_devname(dev_name);
  80         if (!pctldev) {
  81                 ret = -EINVAL;
  82                 return ret;
  83         }
  84
  85         mutex_lock(&pctldev->mutex);
  86
  87         ops = pctldev->desc->confops;
  88
  89         if (!ops || !ops->pin_config_group_get) {
  90                 dev_dbg(pctldev->dev, "cannot get configuration for pin "
  91                         "group, missing group config get function in "
  92                         "driver\n");
  93                 ret = -ENOTSUPP;
  94                 goto unlock;
  95         }
  96
  97         selector = pinctrl_get_group_selector(pctldev, pin_group);
  98         if (selector < 0) {
  99                 ret = selector;
 100                 goto unlock;
 101         }
 102
 103         ret = ops->pin_config_group_get(pctldev, selector, config);
 104
 105 unlock:
 106         mutex_unlock(&pctldev->mutex);
 107         return ret;
 108 }
 109
 110 int pinconf_map_to_setting(struct pinctrl_map const *map,
 111                           struct pinctrl_setting *setting)
 112 {
 113         struct pinctrl_dev *pctldev = setting->pctldev;
 114         int pin;
 115
 116         switch (setting->type) {
 117         case PIN_MAP_TYPE_CONFIGS_PIN:
 118                 pin = pin_get_from_name(pctldev,
 119                                         map->data.configs.group_or_pin);
 120                 if (pin < 0) {
 121                         dev_err(pctldev->dev, "could not map pin config for \"%s\"",
 122                                 map->data.configs.group_or_pin);
 123                         return pin;
 124                 }
 125                 setting->data.configs.group_or_pin = pin;
 126                 break;
 127         case PIN_MAP_TYPE_CONFIGS_GROUP:
 128                 pin = pinctrl_get_group_selector(pctldev,
 129                                          map->data.configs.group_or_pin);
 130                 if (pin < 0) {
 131                         dev_err(pctldev->dev, "could not map group config for \"%s\"",
 132                                 map->data.configs.group_or_pin);
 133                         return pin;
 134                 }
 135                 setting->data.configs.group_or_pin = pin;
 136                 break;
 137         default:
 138                 return -EINVAL;
 139         }
 140
 141         setting->data.configs.num_configs = map->data.configs.num_configs;
 142         setting->data.configs.configs = map->data.configs.configs;
 143
 144         return 0;
 145 }
 146
 147 void pinconf_free_setting(struct pinctrl_setting const *setting)
 148 {
 149 }
 150
 151 int pinconf_apply_setting(struct pinctrl_setting const *setting)
 152 {
 153         struct pinctrl_dev *pctldev = setting->pctldev;
 154         const struct pinconf_ops *ops = pctldev->desc->confops;
 155         int ret;
 156
 157         if (!ops) {
 158                 dev_err(pctldev->dev, "missing confops\n");
 159                 return -EINVAL;
 160         }
 161
 162         switch (setting->type) {
 163         case PIN_MAP_TYPE_CONFIGS_PIN:
 164                 if (!ops->pin_config_set) {
 165                         dev_err(pctldev->dev, "missing pin_config_set op\n");
 166                         return -EINVAL;
 167                 }
 168                 ret = ops->pin_config_set(pctldev,
 169                                 setting->data.configs.group_or_pin,
 170                                 setting->data.configs.configs,
 171                                 setting->data.configs.num_configs);
 172                 if (ret < 0) {
 173                         dev_err(pctldev->dev,
 174                                 "pin_config_set op failed for pin %d\n",
 175                                 setting->data.configs.group_or_pin);
 176                         return ret;
 177                 }
 178                 break;
 179         case PIN_MAP_TYPE_CONFIGS_GROUP:
 180                 if (!ops->pin_config_group_set) {
 181                         dev_err(pctldev->dev,
 182                                 "missing pin_config_group_set op\n");
 183                         return -EINVAL;
 184                 }
 185                 ret = ops->pin_config_group_set(pctldev,
 186                                 setting->data.configs.group_or_pin,
 187                                 setting->data.configs.configs,
 188                                 setting->data.configs.num_configs);
 189                 if (ret < 0) {
 190                         dev_err(pctldev->dev,
 191                                 "pin_config_group_set op failed for group %d\n",
 192                                 setting->data.configs.group_or_pin);
 193                         return ret;
 194                 }
 195                 break;
 196         default:
 197                 return -EINVAL;
 198         }
 199
 200         return 0;
 201 }
 202
 203 #ifdef CONFIG_DEBUG_FS
 204
 205 static void pinconf_show_config(struct seq_file *s, struct pinctrl_dev *pctldev,
 206                       unsigned long *configs, unsigned num_configs)
 207 {
 208         const struct pinconf_ops *confops;
 209         int i;
 210
 211         if (pctldev)
 212                 confops = pctldev->desc->confops;
 213         else
 214                 confops = NULL;
 215
 216         for (i = 0; i < num_configs; i++) {
 217                 seq_puts(s, "config ");
 218                 if (confops && confops->pin_config_config_dbg_show)
 219                         confops->pin_config_config_dbg_show(pctldev, s,
 220                                                             configs[i]);
 221                 else
 222                         seq_printf(s, "%08lx", configs[i]);
 223                 seq_puts(s, "\n");
 224         }
 225 }
 226
 227 void pinconf_show_map(struct seq_file *s, struct pinctrl_map const *map)
 228 {
 229         struct pinctrl_dev *pctldev;
 230
 231         pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
 232
 233         switch (map->type) {
 234         case PIN_MAP_TYPE_CONFIGS_PIN:
 235                 seq_printf(s, "pin ");
 236                 break;
 237         case PIN_MAP_TYPE_CONFIGS_GROUP:
 238                 seq_printf(s, "group ");
 239                 break;
 240         default:
 241                 break;
 242         }
 243
 244         seq_printf(s, "%s\n", map->data.configs.group_or_pin);
 245
 246         pinconf_show_config(s, pctldev, map->data.configs.configs,
 247                             map->data.configs.num_configs);
 248 }
 249
 250 void pinconf_show_setting(struct seq_file *s,
 251                           struct pinctrl_setting const *setting)
 252 {
 253         struct pinctrl_dev *pctldev = setting->pctldev;
 254         const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 255         struct pin_desc *desc;
 256
 257         switch (setting->type) {
 258         case PIN_MAP_TYPE_CONFIGS_PIN:
 259                 desc = pin_desc_get(setting->pctldev,
 260                                     setting->data.configs.group_or_pin);
 261                 seq_printf(s, "pin %s (%d)", desc->name,
 262                            setting->data.configs.group_or_pin);
 263                 break;
 264         case PIN_MAP_TYPE_CONFIGS_GROUP:
 265                 seq_printf(s, "group %s (%d)",
 266                            pctlops->get_group_name(pctldev,
 267                                         setting->data.configs.group_or_pin),
 268                            setting->data.configs.group_or_pin);
 269                 break;
 270         default:
 271                 break;
 272         }
 273
 274         /*
 275          * FIXME: We should really get the pin controler to dump the config
 276          * values, so they can be decoded to something meaningful.
 277          */
 278         pinconf_show_config(s, pctldev, setting->data.configs.configs,
 279                             setting->data.configs.num_configs);
 280 }
 281
 282 static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
 283                              struct seq_file *s, int pin)
 284 {
 285         const struct pinconf_ops *ops = pctldev->desc->confops;
 286
 287         /* no-op when not using generic pin config */
 288         pinconf_generic_dump_pins(pctldev, s, NULL, pin);
 289         if (ops && ops->pin_config_dbg_show)
 290                 ops->pin_config_dbg_show(pctldev, s, pin);
 291 }
 292
 293 static int pinconf_pins_show(struct seq_file *s, void *what)
 294 {
 295         struct pinctrl_dev *pctldev = s->private;
 296         unsigned i, pin;
 297
 298         seq_puts(s, "Pin config settings per pin\n");
 299         seq_puts(s, "Format: pin (name): configs\n");
 300
 301         mutex_lock(&pctldev->mutex);
 302
 303         /* The pin number can be retrived from the pin controller descriptor */
 304         for (i = 0; i < pctldev->desc->npins; i++) {
 305                 struct pin_desc *desc;
 306
 307                 pin = pctldev->desc->pins[i].number;
 308                 desc = pin_desc_get(pctldev, pin);
 309                 /* Skip if we cannot search the pin */
 310                 if (desc == NULL)
 311                         continue;
 312
 313                 seq_printf(s, "pin %d (%s): ", pin, desc->name);
 314
 315                 pinconf_dump_pin(pctldev, s, pin);
 316
 317                 seq_printf(s, "\n");
 318         }
 319
 320         mutex_unlock(&pctldev->mutex);
 321
 322         return 0;
 323 }
 324
 325 static void pinconf_dump_group(struct pinctrl_dev *pctldev,
 326                                struct seq_file *s, unsigned selector,
 327                                const char *gname)
 328 {
 329         const struct pinconf_ops *ops = pctldev->desc->confops;
 330
 331         /* no-op when not using generic pin config */
 332         pinconf_generic_dump_pins(pctldev, s, gname, 0);
 333         if (ops && ops->pin_config_group_dbg_show)
 334                 ops->pin_config_group_dbg_show(pctldev, s, selector);
 335 }
 336
 337 static int pinconf_groups_show(struct seq_file *s, void *what)
 338 {
 339         struct pinctrl_dev *pctldev = s->private;
 340         const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 341         unsigned ngroups = pctlops->get_groups_count(pctldev);
 342         unsigned selector = 0;
 343
 344         seq_puts(s, "Pin config settings per pin group\n");
 345         seq_puts(s, "Format: group (name): configs\n");
 346
 347         while (selector < ngroups) {
 348                 const char *gname = pctlops->get_group_name(pctldev, selector);
 349
 350                 seq_printf(s, "%u (%s): ", selector, gname);
 351                 pinconf_dump_group(pctldev, s, selector, gname);
 352                 seq_printf(s, "\n");
 353
 354                 selector++;
 355         }
 356
 357         return 0;
 358 }
 359
 360 static int pinconf_pins_open(struct inode *inode, struct file *file)
 361 {
 362         return single_open(file, pinconf_pins_show, inode->i_private);
 363 }
 364
 365 static int pinconf_groups_open(struct inode *inode, struct file *file)
 366 {
 367         return single_open(file, pinconf_groups_show, inode->i_private);
 368 }
 369
 370 static const struct file_operations pinconf_pins_ops = {
 371         .open           = pinconf_pins_open,
 372         .read           = seq_read,
 373         .llseek         = seq_lseek,
 374         .release        = single_release,
 375 };
 376
 377 static const struct file_operations pinconf_groups_ops = {
 378         .open           = pinconf_groups_open,
 379         .read           = seq_read,
 380         .llseek         = seq_lseek,
 381         .release        = single_release,
 382 };
 383
 384 #define MAX_NAME_LEN 15
 385
 386 struct dbg_cfg {
 387         enum pinctrl_map_type map_type;
 388         char dev_name[MAX_NAME_LEN+1];
 389         char state_name[MAX_NAME_LEN+1];
 390         char pin_name[MAX_NAME_LEN+1];
 391 };
 392
 393 /*
 394  * Goal is to keep this structure as global in order to simply read the
 395  * pinconf-config file after a write to check config is as expected
 396  */
 397 static struct dbg_cfg pinconf_dbg_conf;
 398
 399 /**
 400  * pinconf_dbg_config_print() - display the pinctrl config from the pinctrl
 401  * map, of the dev/pin/state that was last written to pinconf-config file.
 402  * @s: string filled in  with config description
 403  * @d: not used
 404  */
 405 static int pinconf_dbg_config_print(struct seq_file *s, void *d)
 406 {
 407         struct pinctrl_maps *maps_node;
 408         const struct pinctrl_map *map;
 409         const struct pinctrl_map *found = NULL;
 410         struct pinctrl_dev *pctldev;
 411         struct dbg_cfg *dbg = &pinconf_dbg_conf;
 412         int i;
 413
 414         mutex_lock(&pinctrl_maps_mutex);
 415
 416         /* Parse the pinctrl map and look for the elected pin/state */
 417         for_each_maps(maps_node, i, map) {
 418                 if (map->type != dbg->map_type)
 419                         continue;
 420                 if (strcmp(map->dev_name, dbg->dev_name))
 421                         continue;
 422                 if (strcmp(map->name, dbg->state_name))
 423                         continue;
 424
 425                 if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
 426                         /* We found the right pin */
 427                         found = map;
 428                         break;
 429                 }
 430         }
 431
 432         if (!found) {
 433                 seq_printf(s, "No config found for dev/state/pin, expected:\n");
 434                 seq_printf(s, "Searched dev:%s\n", dbg->dev_name);
 435                 seq_printf(s, "Searched state:%s\n", dbg->state_name);
 436                 seq_printf(s, "Searched pin:%s\n", dbg->pin_name);
 437                 seq_printf(s, "Use: modify config_pin <devname> "\
 438                                 "<state> <pinname> <value>\n");
 439                 goto exit;
 440         }
 441
 442         pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);
 443         seq_printf(s, "Dev %s has config of %s in state %s:\n",
 444                    dbg->dev_name, dbg->pin_name, dbg->state_name);
 445         pinconf_show_config(s, pctldev, found->data.configs.configs,
 446                             found->data.configs.num_configs);
 447
 448 exit:
 449         mutex_unlock(&pinctrl_maps_mutex);
 450
 451         return 0;
 452 }
 453
 454 /**
 455  * pinconf_dbg_config_write() - modify the pinctrl config in the pinctrl
 456  * map, of a dev/pin/state entry based on user entries to pinconf-config
 457  * @user_buf: contains the modification request with expected format:
 458  *     modify <config> <devicename> <state> <name> <newvalue>
 459  * modify is literal string, alternatives like add/delete not supported yet
 460  * <config> is the configuration to be changed. Supported configs are
 461  *     "config_pin" or "config_group", alternatives like config_mux are not
 462  *     supported yet.
 463  * <devicename> <state> <name> are values that should match the pinctrl-maps
 464  * <newvalue> reflects the new config and is driver dependant
 465  */
 466 static ssize_t pinconf_dbg_config_write(struct file *file,
 467         const char __user *user_buf, size_t count, loff_t *ppos)
 468 {
 469         struct pinctrl_maps *maps_node;
 470         const struct pinctrl_map *map;
 471         const struct pinctrl_map *found = NULL;
 472         struct pinctrl_dev *pctldev;
 473         const struct pinconf_ops *confops = NULL;
 474         struct dbg_cfg *dbg = &pinconf_dbg_conf;
 475         const struct pinctrl_map_configs *configs;
 476         char config[MAX_NAME_LEN+1];
 477         char buf[128];
 478         char *b = &buf[0];
 479         int buf_size;
 480         char *token;
 481         int i;
 482
 483         /* Get userspace string and assure termination */
 484         buf_size = min(count, sizeof(buf) - 1);
 485         if (copy_from_user(buf, user_buf, buf_size))
 486                 return -EFAULT;
 487         buf[buf_size] = 0;
 488
 489         /*
 490          * need to parse entry and extract parameters:
 491          * modify configs_pin devicename state pinname newvalue
 492          */
 493
 494         /* Get arg: 'modify' */
 495         token = strsep(&b, " ");
 496         if (!token)
 497                 return -EINVAL;
 498         if (strcmp(token, "modify"))
 499                 return -EINVAL;
 500
 501         /*
 502          * Get arg type: "config_pin" and "config_group"
 503          *                types are supported so far
 504          */
 505         token = strsep(&b, " ");
 506         if (!token)
 507                 return -EINVAL;
 508         if (!strcmp(token, "config_pin"))
 509                 dbg->map_type = PIN_MAP_TYPE_CONFIGS_PIN;
 510         else if (!strcmp(token, "config_group"))
 511                 dbg->map_type = PIN_MAP_TYPE_CONFIGS_GROUP;
 512         else
 513                 return -EINVAL;
 514
 515         /* get arg 'device_name' */
 516         token = strsep(&b, " ");
 517         if (token == NULL)
 518                 return -EINVAL;
 519         if (strlen(token) >= MAX_NAME_LEN)
 520                 return -EINVAL;
 521         strncpy(dbg->dev_name, token, MAX_NAME_LEN);
 522
 523         /* get arg 'state_name' */
 524         token = strsep(&b, " ");
 525         if (token == NULL)
 526                 return -EINVAL;
 527         if (strlen(token) >= MAX_NAME_LEN)
 528                 return -EINVAL;
 529         strncpy(dbg->state_name, token, MAX_NAME_LEN);
 530
 531         /* get arg 'pin_name' */
 532         token = strsep(&b, " ");
 533         if (token == NULL)
 534                 return -EINVAL;
 535         if (strlen(token) >= MAX_NAME_LEN)
 536                 return -EINVAL;
 537         strncpy(dbg->pin_name, token, MAX_NAME_LEN);
 538
 539         /* get new_value of config' */
 540         token = strsep(&b, " ");
 541         if (token == NULL)
 542                 return -EINVAL;
 543         if (strlen(token) >= MAX_NAME_LEN)
 544                 return -EINVAL;
 545         strncpy(config, token, MAX_NAME_LEN);
 546
 547         mutex_lock(&pinctrl_maps_mutex);
 548
 549         /* Parse the pinctrl map and look for the selected dev/state/pin */
 550         for_each_maps(maps_node, i, map) {
 551                 if (strcmp(map->dev_name, dbg->dev_name))
 552                         continue;
 553                 if (map->type != dbg->map_type)
 554                         continue;
 555                 if (strcmp(map->name, dbg->state_name))
 556                         continue;
 557
 558                 /*  we found the right pin / state, so overwrite config */
 559                 if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
 560                         found = map;
 561                         break;
 562                 }
 563         }
 564
 565         if (!found) {
 566                 count = -EINVAL;
 567                 goto exit;
 568         }
 569
 570         pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);
 571         if (pctldev)
 572                 confops = pctldev->desc->confops;
 573
 574         if (confops && confops->pin_config_dbg_parse_modify) {
 575                 configs = &found->data.configs;
 576                 for (i = 0; i < configs->num_configs; i++) {
 577                         confops->pin_config_dbg_parse_modify(pctldev,
 578                                                      config,
 579                                                      &configs->configs[i]);
 580                 }
 581         }
 582
 583 exit:
 584         mutex_unlock(&pinctrl_maps_mutex);
 585
 586         return count;
 587 }
 588
 589 static int pinconf_dbg_config_open(struct inode *inode, struct file *file)
 590 {
 591         return single_open(file, pinconf_dbg_config_print, inode->i_private);
 592 }
 593
 594 static const struct file_operations pinconf_dbg_pinconfig_fops = {
 595         .open = pinconf_dbg_config_open,
 596         .write = pinconf_dbg_config_write,
 597         .read = seq_read,
 598         .llseek = seq_lseek,
 599         .release = single_release,
 600         .owner = THIS_MODULE,
 601 };
 602
 603 void pinconf_init_device_debugfs(struct dentry *devroot,
 604                          struct pinctrl_dev *pctldev)
 605 {
 606         debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO,
 607                             devroot, pctldev, &pinconf_pins_ops);
 608         debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
 609                             devroot, pctldev, &pinconf_groups_ops);
 610         debugfs_create_file("pinconf-config",  (S_IRUGO | S_IWUSR | S_IWGRP),
 611                             devroot, pctldev, &pinconf_dbg_pinconfig_fops);
 612 }
 613
 614 #endif