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,
  91                         "cannot get configuration for pin group, missing group config get function in driver\n");
  92                 ret = -ENOTSUPP;
  93                 goto unlock;
  94         }
  95
  96         selector = pinctrl_get_group_selector(pctldev, pin_group);
  97         if (selector < 0) {
  98                 ret = selector;
  99                 goto unlock;
 100         }
 101
 102         ret = ops->pin_config_group_get(pctldev, selector, config);
 103
 104 unlock:
 105         mutex_unlock(&pctldev->mutex);
 106         return ret;
 107 }
 108
 109 int pinconf_map_to_setting(struct pinctrl_map const *map,
 110                           struct pinctrl_setting *setting)
 111 {
 112         struct pinctrl_dev *pctldev = setting->pctldev;
 113         int pin;
 114
 115         switch (setting->type) {
 116         case PIN_MAP_TYPE_CONFIGS_PIN:
 117                 pin = pin_get_from_name(pctldev,
 118                                         map->data.configs.group_or_pin);
 119                 if (pin < 0) {
 120                         dev_err(pctldev->dev, "could not map pin config for \"%s\"",
 121                                 map->data.configs.group_or_pin);
 122                         return pin;
 123                 }
 124                 setting->data.configs.group_or_pin = pin;
 125                 break;
 126         case PIN_MAP_TYPE_CONFIGS_GROUP:
 127                 pin = pinctrl_get_group_selector(pctldev,
 128                                          map->data.configs.group_or_pin);
 129                 if (pin < 0) {
 130                         dev_err(pctldev->dev, "could not map group config for \"%s\"",
 131                                 map->data.configs.group_or_pin);
 132                         return pin;
 133                 }
 134                 setting->data.configs.group_or_pin = pin;
 135                 break;
 136         default:
 137                 return -EINVAL;
 138         }
 139
 140         setting->data.configs.num_configs = map->data.configs.num_configs;
 141         setting->data.configs.configs = map->data.configs.configs;
 142
 143         return 0;
 144 }
 145
 146 void pinconf_free_setting(struct pinctrl_setting const *setting)
 147 {
 148 }
 149
 150 int pinconf_apply_setting(struct pinctrl_setting const *setting)
 151 {
 152         struct pinctrl_dev *pctldev = setting->pctldev;
 153         const struct pinconf_ops *ops = pctldev->desc->confops;
 154         int ret;
 155
 156         if (!ops) {
 157                 dev_err(pctldev->dev, "missing confops\n");
 158                 return -EINVAL;
 159         }
 160
 161         switch (setting->type) {
 162         case PIN_MAP_TYPE_CONFIGS_PIN:
 163                 if (!ops->pin_config_set) {
 164                         dev_err(pctldev->dev, "missing pin_config_set op\n");
 165                         return -EINVAL;
 166                 }
 167                 ret = ops->pin_config_set(pctldev,
 168                                 setting->data.configs.group_or_pin,
 169                                 setting->data.configs.configs,
 170                                 setting->data.configs.num_configs);
 171                 if (ret < 0) {
 172                         dev_err(pctldev->dev,
 173                                 "pin_config_set op failed for pin %d\n",
 174                                 setting->data.configs.group_or_pin);
 175                         return ret;
 176                 }
 177                 break;
 178         case PIN_MAP_TYPE_CONFIGS_GROUP:
 179                 if (!ops->pin_config_group_set) {
 180                         dev_err(pctldev->dev,
 181                                 "missing pin_config_group_set op\n");
 182                         return -EINVAL;
 183                 }
 184                 ret = ops->pin_config_group_set(pctldev,
 185                                 setting->data.configs.group_or_pin,
 186                                 setting->data.configs.configs,
 187                                 setting->data.configs.num_configs);
 188                 if (ret < 0) {
 189                         dev_err(pctldev->dev,
 190                                 "pin_config_group_set op failed for group %d\n",
 191                                 setting->data.configs.group_or_pin);
 192                         return ret;
 193                 }
 194                 break;
 195         default:
 196                 return -EINVAL;
 197         }
 198
 199         return 0;
 200 }
 201
 202 int pinconf_set_config(struct pinctrl_dev *pctldev, unsigned pin,
 203                        unsigned long *configs, size_t nconfigs)
 204 {
 205         const struct pinconf_ops *ops;
 206
 207         ops = pctldev->desc->confops;
 208         if (!ops)
 209                 return -ENOTSUPP;
 210
 211         return ops->pin_config_set(pctldev, pin, configs, nconfigs);
 212 }
 213
 214 #ifdef CONFIG_DEBUG_FS
 215
 216 static void pinconf_show_config(struct seq_file *s, struct pinctrl_dev *pctldev,
 217                       unsigned long *configs, unsigned num_configs)
 218 {
 219         const struct pinconf_ops *confops;
 220         int i;
 221
 222         if (pctldev)
 223                 confops = pctldev->desc->confops;
 224         else
 225                 confops = NULL;
 226
 227         for (i = 0; i < num_configs; i++) {
 228                 seq_puts(s, "config ");
 229                 if (confops && confops->pin_config_config_dbg_show)
 230                         confops->pin_config_config_dbg_show(pctldev, s,
 231                                                             configs[i]);
 232                 else
 233                         seq_printf(s, "%08lx", configs[i]);
 234                 seq_putc(s, '\n');
 235         }
 236 }
 237
 238 void pinconf_show_map(struct seq_file *s, struct pinctrl_map const *map)
 239 {
 240         struct pinctrl_dev *pctldev;
 241
 242         pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
 243
 244         switch (map->type) {
 245         case PIN_MAP_TYPE_CONFIGS_PIN:
 246                 seq_puts(s, "pin ");
 247                 break;
 248         case PIN_MAP_TYPE_CONFIGS_GROUP:
 249                 seq_puts(s, "group ");
 250                 break;
 251         default:
 252                 break;
 253         }
 254
 255         seq_printf(s, "%s\n", map->data.configs.group_or_pin);
 256
 257         pinconf_show_config(s, pctldev, map->data.configs.configs,
 258                             map->data.configs.num_configs);
 259 }
 260
 261 void pinconf_show_setting(struct seq_file *s,
 262                           struct pinctrl_setting const *setting)
 263 {
 264         struct pinctrl_dev *pctldev = setting->pctldev;
 265         const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 266         struct pin_desc *desc;
 267
 268         switch (setting->type) {
 269         case PIN_MAP_TYPE_CONFIGS_PIN:
 270                 desc = pin_desc_get(setting->pctldev,
 271                                     setting->data.configs.group_or_pin);
 272                 seq_printf(s, "pin %s (%d)", desc->name,
 273                            setting->data.configs.group_or_pin);
 274                 break;
 275         case PIN_MAP_TYPE_CONFIGS_GROUP:
 276                 seq_printf(s, "group %s (%d)",
 277                            pctlops->get_group_name(pctldev,
 278                                         setting->data.configs.group_or_pin),
 279                            setting->data.configs.group_or_pin);
 280                 break;
 281         default:
 282                 break;
 283         }
 284
 285         /*
 286          * FIXME: We should really get the pin controller to dump the config
 287          * values, so they can be decoded to something meaningful.
 288          */
 289         pinconf_show_config(s, pctldev, setting->data.configs.configs,
 290                             setting->data.configs.num_configs);
 291 }
 292
 293 static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
 294                              struct seq_file *s, int pin)
 295 {
 296         const struct pinconf_ops *ops = pctldev->desc->confops;
 297
 298         /* no-op when not using generic pin config */
 299         pinconf_generic_dump_pins(pctldev, s, NULL, pin);
 300         if (ops && ops->pin_config_dbg_show)
 301                 ops->pin_config_dbg_show(pctldev, s, pin);
 302 }
 303
 304 static int pinconf_pins_show(struct seq_file *s, void *what)
 305 {
 306         struct pinctrl_dev *pctldev = s->private;
 307         unsigned i, pin;
 308
 309         seq_puts(s, "Pin config settings per pin\n");
 310         seq_puts(s, "Format: pin (name): configs\n");
 311
 312         mutex_lock(&pctldev->mutex);
 313
 314         /* The pin number can be retrived from the pin controller descriptor */
 315         for (i = 0; i < pctldev->desc->npins; i++) {
 316                 struct pin_desc *desc;
 317
 318                 pin = pctldev->desc->pins[i].number;
 319                 desc = pin_desc_get(pctldev, pin);
 320                 /* Skip if we cannot search the pin */
 321                 if (!desc)
 322                         continue;
 323
 324                 seq_printf(s, "pin %d (%s): ", pin, desc->name);
 325
 326                 pinconf_dump_pin(pctldev, s, pin);
 327                 seq_putc(s, '\n');
 328         }
 329
 330         mutex_unlock(&pctldev->mutex);
 331
 332         return 0;
 333 }
 334
 335 static void pinconf_dump_group(struct pinctrl_dev *pctldev,
 336                                struct seq_file *s, unsigned selector,
 337                                const char *gname)
 338 {
 339         const struct pinconf_ops *ops = pctldev->desc->confops;
 340
 341         /* no-op when not using generic pin config */
 342         pinconf_generic_dump_pins(pctldev, s, gname, 0);
 343         if (ops && ops->pin_config_group_dbg_show)
 344                 ops->pin_config_group_dbg_show(pctldev, s, selector);
 345 }
 346
 347 static int pinconf_groups_show(struct seq_file *s, void *what)
 348 {
 349         struct pinctrl_dev *pctldev = s->private;
 350         const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 351         unsigned ngroups = pctlops->get_groups_count(pctldev);
 352         unsigned selector = 0;
 353
 354         seq_puts(s, "Pin config settings per pin group\n");
 355         seq_puts(s, "Format: group (name): configs\n");
 356
 357         while (selector < ngroups) {
 358                 const char *gname = pctlops->get_group_name(pctldev, selector);
 359
 360                 seq_printf(s, "%u (%s): ", selector, gname);
 361                 pinconf_dump_group(pctldev, s, selector, gname);
 362                 seq_putc(s, '\n');
 363                 selector++;
 364         }
 365
 366         return 0;
 367 }
 368
 369 static int pinconf_pins_open(struct inode *inode, struct file *file)
 370 {
 371         return single_open(file, pinconf_pins_show, inode->i_private);
 372 }
 373
 374 static int pinconf_groups_open(struct inode *inode, struct file *file)
 375 {
 376         return single_open(file, pinconf_groups_show, inode->i_private);
 377 }
 378
 379 static const struct file_operations pinconf_pins_ops = {
 380         .open           = pinconf_pins_open,
 381         .read           = seq_read,
 382         .llseek         = seq_lseek,
 383         .release        = single_release,
 384 };
 385
 386 static const struct file_operations pinconf_groups_ops = {
 387         .open           = pinconf_groups_open,
 388         .read           = seq_read,
 389         .llseek         = seq_lseek,
 390         .release        = single_release,
 391 };
 392
 393 #define MAX_NAME_LEN 15
 394
 395 struct dbg_cfg {
 396         enum pinctrl_map_type map_type;
 397         char dev_name[MAX_NAME_LEN + 1];
 398         char state_name[MAX_NAME_LEN + 1];
 399         char pin_name[MAX_NAME_LEN + 1];
 400 };
 401
 402 /*
 403  * Goal is to keep this structure as global in order to simply read the
 404  * pinconf-config file after a write to check config is as expected
 405  */
 406 static struct dbg_cfg pinconf_dbg_conf;
 407
 408 /**
 409  * pinconf_dbg_config_print() - display the pinctrl config from the pinctrl
 410  * map, of the dev/pin/state that was last written to pinconf-config file.
 411  * @s: string filled in  with config description
 412  * @d: not used
 413  */
 414 static int pinconf_dbg_config_print(struct seq_file *s, void *d)
 415 {
 416         struct pinctrl_maps *maps_node;
 417         const struct pinctrl_map *map;
 418         const struct pinctrl_map *found = NULL;
 419         struct pinctrl_dev *pctldev;
 420         struct dbg_cfg *dbg = &pinconf_dbg_conf;
 421         int i;
 422
 423         mutex_lock(&pinctrl_maps_mutex);
 424
 425         /* Parse the pinctrl map and look for the elected pin/state */
 426         for_each_maps(maps_node, i, map) {
 427                 if (map->type != dbg->map_type)
 428                         continue;
 429                 if (strcmp(map->dev_name, dbg->dev_name))
 430                         continue;
 431                 if (strcmp(map->name, dbg->state_name))
 432                         continue;
 433
 434                 if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
 435                         /* We found the right pin */
 436                         found = map;
 437                         break;
 438                 }
 439         }
 440
 441         if (!found) {
 442                 seq_printf(s, "No config found for dev/state/pin, expected:\n");
 443                 seq_printf(s, "Searched dev:%s\n", dbg->dev_name);
 444                 seq_printf(s, "Searched state:%s\n", dbg->state_name);
 445                 seq_printf(s, "Searched pin:%s\n", dbg->pin_name);
 446                 seq_printf(s, "Use: modify config_pin <devname> "\
 447                                 "<state> <pinname> <value>\n");
 448                 goto exit;
 449         }
 450
 451         pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);
 452         seq_printf(s, "Dev %s has config of %s in state %s:\n",
 453                    dbg->dev_name, dbg->pin_name, dbg->state_name);
 454         pinconf_show_config(s, pctldev, found->data.configs.configs,
 455                             found->data.configs.num_configs);
 456
 457 exit:
 458         mutex_unlock(&pinctrl_maps_mutex);
 459
 460         return 0;
 461 }
 462
 463 /**
 464  * pinconf_dbg_config_write() - modify the pinctrl config in the pinctrl
 465  * map, of a dev/pin/state entry based on user entries to pinconf-config
 466  * @user_buf: contains the modification request with expected format:
 467  *     modify <config> <devicename> <state> <name> <newvalue>
 468  * modify is literal string, alternatives like add/delete not supported yet
 469  * <config> is the configuration to be changed. Supported configs are
 470  *     "config_pin" or "config_group", alternatives like config_mux are not
 471  *     supported yet.
 472  * <devicename> <state> <name> are values that should match the pinctrl-maps
 473  * <newvalue> reflects the new config and is driver dependent
 474  */
 475 static ssize_t pinconf_dbg_config_write(struct file *file,
 476         const char __user *user_buf, size_t count, loff_t *ppos)
 477 {
 478         struct pinctrl_maps *maps_node;
 479         const struct pinctrl_map *map;
 480         const struct pinctrl_map *found = NULL;
 481         struct pinctrl_dev *pctldev;
 482         const struct pinconf_ops *confops = NULL;
 483         struct dbg_cfg *dbg = &pinconf_dbg_conf;
 484         const struct pinctrl_map_configs *configs;
 485         char config[MAX_NAME_LEN + 1];
 486         char buf[128];
 487         char *b = &buf[0];
 488         int buf_size;
 489         char *token;
 490         int i;
 491
 492         /* Get userspace string and assure termination */
 493         buf_size = min(count, sizeof(buf) - 1);
 494         if (copy_from_user(buf, user_buf, buf_size))
 495                 return -EFAULT;
 496         buf[buf_size] = 0;
 497
 498         /*
 499          * need to parse entry and extract parameters:
 500          * modify configs_pin devicename state pinname newvalue
 501          */
 502
 503         /* Get arg: 'modify' */
 504         token = strsep(&b, " ");
 505         if (!token)
 506                 return -EINVAL;
 507         if (strcmp(token, "modify"))
 508                 return -EINVAL;
 509
 510         /*
 511          * Get arg type: "config_pin" and "config_group"
 512          *                types are supported so far
 513          */
 514         token = strsep(&b, " ");
 515         if (!token)
 516                 return -EINVAL;
 517         if (!strcmp(token, "config_pin"))
 518                 dbg->map_type = PIN_MAP_TYPE_CONFIGS_PIN;
 519         else if (!strcmp(token, "config_group"))
 520                 dbg->map_type = PIN_MAP_TYPE_CONFIGS_GROUP;
 521         else
 522                 return -EINVAL;
 523
 524         /* get arg 'device_name' */
 525         token = strsep(&b, " ");
 526         if (!token)
 527                 return -EINVAL;
 528         if (strlen(token) >= MAX_NAME_LEN)
 529                 return -EINVAL;
 530         strncpy(dbg->dev_name, token, MAX_NAME_LEN);
 531
 532         /* get arg 'state_name' */
 533         token = strsep(&b, " ");
 534         if (!token)
 535                 return -EINVAL;
 536         if (strlen(token) >= MAX_NAME_LEN)
 537                 return -EINVAL;
 538         strncpy(dbg->state_name, token, MAX_NAME_LEN);
 539
 540         /* get arg 'pin_name' */
 541         token = strsep(&b, " ");
 542         if (!token)
 543                 return -EINVAL;
 544         if (strlen(token) >= MAX_NAME_LEN)
 545                 return -EINVAL;
 546         strncpy(dbg->pin_name, token, MAX_NAME_LEN);
 547
 548         /* get new_value of config' */
 549         token = strsep(&b, " ");
 550         if (!token)
 551                 return -EINVAL;
 552         if (strlen(token) >= MAX_NAME_LEN)
 553                 return -EINVAL;
 554         strncpy(config, token, MAX_NAME_LEN);
 555
 556         mutex_lock(&pinctrl_maps_mutex);
 557
 558         /* Parse the pinctrl map and look for the selected dev/state/pin */
 559         for_each_maps(maps_node, i, map) {
 560                 if (strcmp(map->dev_name, dbg->dev_name))
 561                         continue;
 562                 if (map->type != dbg->map_type)
 563                         continue;
 564                 if (strcmp(map->name, dbg->state_name))
 565                         continue;
 566
 567                 /*  we found the right pin / state, so overwrite config */
 568                 if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
 569                         found = map;
 570                         break;
 571                 }
 572         }
 573
 574         if (!found) {
 575                 count = -EINVAL;
 576                 goto exit;
 577         }
 578
 579         pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);
 580         if (pctldev)
 581                 confops = pctldev->desc->confops;
 582
 583         if (confops && confops->pin_config_dbg_parse_modify) {
 584                 configs = &found->data.configs;
 585                 for (i = 0; i < configs->num_configs; i++) {
 586                         confops->pin_config_dbg_parse_modify(pctldev,
 587                                                      config,
 588                                                      &configs->configs[i]);
 589                 }
 590         }
 591
 592 exit:
 593         mutex_unlock(&pinctrl_maps_mutex);
 594
 595         return count;
 596 }
 597
 598 static int pinconf_dbg_config_open(struct inode *inode, struct file *file)
 599 {
 600         return single_open(file, pinconf_dbg_config_print, inode->i_private);
 601 }
 602
 603 static const struct file_operations pinconf_dbg_pinconfig_fops = {
 604         .open = pinconf_dbg_config_open,
 605         .write = pinconf_dbg_config_write,
 606         .read = seq_read,
 607         .llseek = seq_lseek,
 608         .release = single_release,
 609         .owner = THIS_MODULE,
 610 };
 611
 612 void pinconf_init_device_debugfs(struct dentry *devroot,
 613                          struct pinctrl_dev *pctldev)
 614 {
 615         debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO,
 616                             devroot, pctldev, &pinconf_pins_ops);
 617         debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
 618                             devroot, pctldev, &pinconf_groups_ops);
 619         debugfs_create_file("pinconf-config",  (S_IRUGO | S_IWUSR | S_IWGRP),
 620                             devroot, pctldev, &pinconf_dbg_pinconfig_fops);
 621 }
 622
 623 #endif