linux/drivers/pinctrl/pinconf.c
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   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
  27int pinconf_check_ops(struct pinctrl_dev *pctldev)
  28{
  29        const struct pinconf_ops *ops = pctldev->desc->confops;
  30
  31        /* We must be able to read out pin status */
  32        if (!ops->pin_config_get && !ops->pin_config_group_get) {
  33                dev_err(pctldev->dev,
  34                        "pinconf must be able to read out pin status\n");
  35                return -EINVAL;
  36        }
  37        /* We have to be able to config the pins in SOME way */
  38        if (!ops->pin_config_set && !ops->pin_config_group_set) {
  39                dev_err(pctldev->dev,
  40                        "pinconf has to be able to set a pins config\n");
  41                return -EINVAL;
  42        }
  43        return 0;
  44}
  45
  46int pinconf_validate_map(struct pinctrl_map const *map, int i)
  47{
  48        if (!map->data.configs.group_or_pin) {
  49                pr_err("failed to register map %s (%d): no group/pin given\n",
  50                       map->name, i);
  51                return -EINVAL;
  52        }
  53
  54        if (!map->data.configs.num_configs ||
  55                        !map->data.configs.configs) {
  56                pr_err("failed to register map %s (%d): no configs given\n",
  57                       map->name, i);
  58                return -EINVAL;
  59        }
  60
  61        return 0;
  62}
  63
  64int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
  65                           unsigned long *config)
  66{
  67        const struct pinconf_ops *ops = pctldev->desc->confops;
  68
  69        if (!ops || !ops->pin_config_get) {
  70                dev_err(pctldev->dev, "cannot get pin configuration, missing "
  71                        "pin_config_get() function in driver\n");
  72                return -EINVAL;
  73        }
  74
  75        return ops->pin_config_get(pctldev, pin, config);
  76}
  77
  78int pin_config_group_get(const char *dev_name, const char *pin_group,
  79                         unsigned long *config)
  80{
  81        struct pinctrl_dev *pctldev;
  82        const struct pinconf_ops *ops;
  83        int selector, ret;
  84
  85        pctldev = get_pinctrl_dev_from_devname(dev_name);
  86        if (!pctldev) {
  87                ret = -EINVAL;
  88                return ret;
  89        }
  90
  91        mutex_lock(&pctldev->mutex);
  92
  93        ops = pctldev->desc->confops;
  94
  95        if (!ops || !ops->pin_config_group_get) {
  96                dev_err(pctldev->dev, "cannot get configuration for pin "
  97                        "group, missing group config get function in "
  98                        "driver\n");
  99                ret = -EINVAL;
 100                goto unlock;
 101        }
 102
 103        selector = pinctrl_get_group_selector(pctldev, pin_group);
 104        if (selector < 0) {
 105                ret = selector;
 106                goto unlock;
 107        }
 108
 109        ret = ops->pin_config_group_get(pctldev, selector, config);
 110
 111unlock:
 112        mutex_unlock(&pctldev->mutex);
 113        return ret;
 114}
 115
 116int pinconf_map_to_setting(struct pinctrl_map const *map,
 117                          struct pinctrl_setting *setting)
 118{
 119        struct pinctrl_dev *pctldev = setting->pctldev;
 120        int pin;
 121
 122        switch (setting->type) {
 123        case PIN_MAP_TYPE_CONFIGS_PIN:
 124                pin = pin_get_from_name(pctldev,
 125                                        map->data.configs.group_or_pin);
 126                if (pin < 0) {
 127                        dev_err(pctldev->dev, "could not map pin config for \"%s\"",
 128                                map->data.configs.group_or_pin);
 129                        return pin;
 130                }
 131                setting->data.configs.group_or_pin = pin;
 132                break;
 133        case PIN_MAP_TYPE_CONFIGS_GROUP:
 134                pin = pinctrl_get_group_selector(pctldev,
 135                                         map->data.configs.group_or_pin);
 136                if (pin < 0) {
 137                        dev_err(pctldev->dev, "could not map group config for \"%s\"",
 138                                map->data.configs.group_or_pin);
 139                        return pin;
 140                }
 141                setting->data.configs.group_or_pin = pin;
 142                break;
 143        default:
 144                return -EINVAL;
 145        }
 146
 147        setting->data.configs.num_configs = map->data.configs.num_configs;
 148        setting->data.configs.configs = map->data.configs.configs;
 149
 150        return 0;
 151}
 152
 153void pinconf_free_setting(struct pinctrl_setting const *setting)
 154{
 155}
 156
 157int pinconf_apply_setting(struct pinctrl_setting const *setting)
 158{
 159        struct pinctrl_dev *pctldev = setting->pctldev;
 160        const struct pinconf_ops *ops = pctldev->desc->confops;
 161        int i, ret;
 162
 163        if (!ops) {
 164                dev_err(pctldev->dev, "missing confops\n");
 165                return -EINVAL;
 166        }
 167
 168        switch (setting->type) {
 169        case PIN_MAP_TYPE_CONFIGS_PIN:
 170                if (!ops->pin_config_set) {
 171                        dev_err(pctldev->dev, "missing pin_config_set op\n");
 172                        return -EINVAL;
 173                }
 174                for (i = 0; i < setting->data.configs.num_configs; i++) {
 175                        ret = ops->pin_config_set(pctldev,
 176                                        setting->data.configs.group_or_pin,
 177                                        setting->data.configs.configs[i]);
 178                        if (ret < 0) {
 179                                dev_err(pctldev->dev,
 180                                        "pin_config_set op failed for pin %d config %08lx\n",
 181                                        setting->data.configs.group_or_pin,
 182                                        setting->data.configs.configs[i]);
 183                                return ret;
 184                        }
 185                }
 186                break;
 187        case PIN_MAP_TYPE_CONFIGS_GROUP:
 188                if (!ops->pin_config_group_set) {
 189                        dev_err(pctldev->dev,
 190                                "missing pin_config_group_set op\n");
 191                        return -EINVAL;
 192                }
 193                for (i = 0; i < setting->data.configs.num_configs; i++) {
 194                        ret = ops->pin_config_group_set(pctldev,
 195                                        setting->data.configs.group_or_pin,
 196                                        setting->data.configs.configs[i]);
 197                        if (ret < 0) {
 198                                dev_err(pctldev->dev,
 199                                        "pin_config_group_set op failed for group %d config %08lx\n",
 200                                        setting->data.configs.group_or_pin,
 201                                        setting->data.configs.configs[i]);
 202                                return ret;
 203                        }
 204                }
 205                break;
 206        default:
 207                return -EINVAL;
 208        }
 209
 210        return 0;
 211}
 212
 213#ifdef CONFIG_DEBUG_FS
 214
 215void pinconf_show_map(struct seq_file *s, struct pinctrl_map const *map)
 216{
 217        struct pinctrl_dev *pctldev;
 218        const struct pinconf_ops *confops;
 219        int i;
 220
 221        pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
 222        if (pctldev)
 223                confops = pctldev->desc->confops;
 224        else
 225                confops = NULL;
 226
 227        switch (map->type) {
 228        case PIN_MAP_TYPE_CONFIGS_PIN:
 229                seq_printf(s, "pin ");
 230                break;
 231        case PIN_MAP_TYPE_CONFIGS_GROUP:
 232                seq_printf(s, "group ");
 233                break;
 234        default:
 235                break;
 236        }
 237
 238        seq_printf(s, "%s\n", map->data.configs.group_or_pin);
 239
 240        for (i = 0; i < map->data.configs.num_configs; i++) {
 241                seq_printf(s, "config ");
 242                if (confops && confops->pin_config_config_dbg_show)
 243                        confops->pin_config_config_dbg_show(pctldev, s,
 244                                                map->data.configs.configs[i]);
 245                else
 246                        seq_printf(s, "%08lx", map->data.configs.configs[i]);
 247                seq_printf(s, "\n");
 248        }
 249}
 250
 251void pinconf_show_setting(struct seq_file *s,
 252                          struct pinctrl_setting const *setting)
 253{
 254        struct pinctrl_dev *pctldev = setting->pctldev;
 255        const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 256        const struct pinconf_ops *confops = pctldev->desc->confops;
 257        struct pin_desc *desc;
 258        int i;
 259
 260        switch (setting->type) {
 261        case PIN_MAP_TYPE_CONFIGS_PIN:
 262                desc = pin_desc_get(setting->pctldev,
 263                                    setting->data.configs.group_or_pin);
 264                seq_printf(s, "pin %s (%d)",
 265                           desc->name ? desc->name : "unnamed",
 266                           setting->data.configs.group_or_pin);
 267                break;
 268        case PIN_MAP_TYPE_CONFIGS_GROUP:
 269                seq_printf(s, "group %s (%d)",
 270                           pctlops->get_group_name(pctldev,
 271                                        setting->data.configs.group_or_pin),
 272                           setting->data.configs.group_or_pin);
 273                break;
 274        default:
 275                break;
 276        }
 277
 278        /*
 279         * FIXME: We should really get the pin controler to dump the config
 280         * values, so they can be decoded to something meaningful.
 281         */
 282        for (i = 0; i < setting->data.configs.num_configs; i++) {
 283                seq_printf(s, " ");
 284                if (confops && confops->pin_config_config_dbg_show)
 285                        confops->pin_config_config_dbg_show(pctldev, s,
 286                                setting->data.configs.configs[i]);
 287                else
 288                        seq_printf(s, "%08lx",
 289                                   setting->data.configs.configs[i]);
 290        }
 291
 292        seq_printf(s, "\n");
 293}
 294
 295static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
 296                             struct seq_file *s, int pin)
 297{
 298        const struct pinconf_ops *ops = pctldev->desc->confops;
 299
 300        /* no-op when not using generic pin config */
 301        pinconf_generic_dump_pin(pctldev, s, pin);
 302        if (ops && ops->pin_config_dbg_show)
 303                ops->pin_config_dbg_show(pctldev, s, pin);
 304}
 305
 306static int pinconf_pins_show(struct seq_file *s, void *what)
 307{
 308        struct pinctrl_dev *pctldev = s->private;
 309        const struct pinconf_ops *ops = pctldev->desc->confops;
 310        unsigned i, pin;
 311
 312        if (!ops || !ops->pin_config_get)
 313                return 0;
 314
 315        seq_puts(s, "Pin config settings per pin\n");
 316        seq_puts(s, "Format: pin (name): configs\n");
 317
 318        mutex_lock(&pctldev->mutex);
 319
 320        /* The pin number can be retrived from the pin controller descriptor */
 321        for (i = 0; i < pctldev->desc->npins; i++) {
 322                struct pin_desc *desc;
 323
 324                pin = pctldev->desc->pins[i].number;
 325                desc = pin_desc_get(pctldev, pin);
 326                /* Skip if we cannot search the pin */
 327                if (desc == NULL)
 328                        continue;
 329
 330                seq_printf(s, "pin %d (%s):", pin,
 331                           desc->name ? desc->name : "unnamed");
 332
 333                pinconf_dump_pin(pctldev, s, pin);
 334
 335                seq_printf(s, "\n");
 336        }
 337
 338        mutex_unlock(&pctldev->mutex);
 339
 340        return 0;
 341}
 342
 343static void pinconf_dump_group(struct pinctrl_dev *pctldev,
 344                               struct seq_file *s, unsigned selector,
 345                               const char *gname)
 346{
 347        const struct pinconf_ops *ops = pctldev->desc->confops;
 348
 349        /* no-op when not using generic pin config */
 350        pinconf_generic_dump_group(pctldev, s, gname);
 351        if (ops && ops->pin_config_group_dbg_show)
 352                ops->pin_config_group_dbg_show(pctldev, s, selector);
 353}
 354
 355static int pinconf_groups_show(struct seq_file *s, void *what)
 356{
 357        struct pinctrl_dev *pctldev = s->private;
 358        const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 359        const struct pinconf_ops *ops = pctldev->desc->confops;
 360        unsigned ngroups = pctlops->get_groups_count(pctldev);
 361        unsigned selector = 0;
 362
 363        if (!ops || !ops->pin_config_group_get)
 364                return 0;
 365
 366        seq_puts(s, "Pin config settings per pin group\n");
 367        seq_puts(s, "Format: group (name): configs\n");
 368
 369        while (selector < ngroups) {
 370                const char *gname = pctlops->get_group_name(pctldev, selector);
 371
 372                seq_printf(s, "%u (%s):", selector, gname);
 373                pinconf_dump_group(pctldev, s, selector, gname);
 374                seq_printf(s, "\n");
 375
 376                selector++;
 377        }
 378
 379        return 0;
 380}
 381
 382static int pinconf_pins_open(struct inode *inode, struct file *file)
 383{
 384        return single_open(file, pinconf_pins_show, inode->i_private);
 385}
 386
 387static int pinconf_groups_open(struct inode *inode, struct file *file)
 388{
 389        return single_open(file, pinconf_groups_show, inode->i_private);
 390}
 391
 392static const struct file_operations pinconf_pins_ops = {
 393        .open           = pinconf_pins_open,
 394        .read           = seq_read,
 395        .llseek         = seq_lseek,
 396        .release        = single_release,
 397};
 398
 399static const struct file_operations pinconf_groups_ops = {
 400        .open           = pinconf_groups_open,
 401        .read           = seq_read,
 402        .llseek         = seq_lseek,
 403        .release        = single_release,
 404};
 405
 406#define MAX_NAME_LEN 15
 407
 408struct dbg_cfg {
 409        enum pinctrl_map_type map_type;
 410        char dev_name[MAX_NAME_LEN+1];
 411        char state_name[MAX_NAME_LEN+1];
 412        char pin_name[MAX_NAME_LEN+1];
 413};
 414
 415/*
 416 * Goal is to keep this structure as global in order to simply read the
 417 * pinconf-config file after a write to check config is as expected
 418 */
 419static struct dbg_cfg pinconf_dbg_conf;
 420
 421/**
 422 * pinconf_dbg_config_print() - display the pinctrl config from the pinctrl
 423 * map, of the dev/pin/state that was last written to pinconf-config file.
 424 * @s: string filled in  with config description
 425 * @d: not used
 426 */
 427static int pinconf_dbg_config_print(struct seq_file *s, void *d)
 428{
 429        struct pinctrl_maps *maps_node;
 430        const struct pinctrl_map *map;
 431        struct pinctrl_dev *pctldev = NULL;
 432        const struct pinconf_ops *confops = NULL;
 433        const struct pinctrl_map_configs *configs;
 434        struct dbg_cfg *dbg = &pinconf_dbg_conf;
 435        int i, j;
 436        bool found = false;
 437        unsigned long config;
 438
 439        mutex_lock(&pinctrl_maps_mutex);
 440
 441        /* Parse the pinctrl map and look for the elected pin/state */
 442        for_each_maps(maps_node, i, map) {
 443                if (map->type != dbg->map_type)
 444                        continue;
 445                if (strcmp(map->dev_name, dbg->dev_name))
 446                        continue;
 447                if (strcmp(map->name, dbg->state_name))
 448                        continue;
 449
 450                for (j = 0; j < map->data.configs.num_configs; j++) {
 451                        if (!strcmp(map->data.configs.group_or_pin,
 452                                        dbg->pin_name)) {
 453                                /*
 454                                 * We found the right pin / state, read the
 455                                 * config and he pctldev for later use
 456                                 */
 457                                configs = &map->data.configs;
 458                                pctldev = get_pinctrl_dev_from_devname
 459                                        (map->ctrl_dev_name);
 460                                found = true;
 461                                break;
 462                        }
 463                }
 464        }
 465
 466        if (!found) {
 467                seq_printf(s, "No config found for dev/state/pin, expected:\n");
 468                seq_printf(s, "Searched dev:%s\n", dbg->dev_name);
 469                seq_printf(s, "Searched state:%s\n", dbg->state_name);
 470                seq_printf(s, "Searched pin:%s\n", dbg->pin_name);
 471                seq_printf(s, "Use: modify config_pin <devname> "\
 472                                "<state> <pinname> <value>\n");
 473                goto exit;
 474        }
 475
 476        config = *(configs->configs);
 477        seq_printf(s, "Dev %s has config of %s in state %s: 0x%08lX\n",
 478                        dbg->dev_name, dbg->pin_name,
 479                        dbg->state_name, config);
 480
 481        if (pctldev)
 482                confops = pctldev->desc->confops;
 483
 484        if (confops && confops->pin_config_config_dbg_show)
 485                confops->pin_config_config_dbg_show(pctldev, s, config);
 486
 487exit:
 488        mutex_unlock(&pinctrl_maps_mutex);
 489
 490        return 0;
 491}
 492
 493/**
 494 * pinconf_dbg_config_write() - modify the pinctrl config in the pinctrl
 495 * map, of a dev/pin/state entry based on user entries to pinconf-config
 496 * @user_buf: contains the modification request with expected format:
 497 *     modify config_pin <devicename> <state> <pinname> <newvalue>
 498 * modify is literal string, alternatives like add/delete not supported yet
 499 * config_pin is literal, alternatives like config_mux not supported yet
 500 * <devicename> <state> <pinname> are values that should match the pinctrl-maps
 501 * <newvalue> reflects the new config and is driver dependant
 502 */
 503static int pinconf_dbg_config_write(struct file *file,
 504        const char __user *user_buf, size_t count, loff_t *ppos)
 505{
 506        struct pinctrl_maps *maps_node;
 507        const struct pinctrl_map *map;
 508        struct pinctrl_dev *pctldev = NULL;
 509        const struct pinconf_ops *confops = NULL;
 510        struct dbg_cfg *dbg = &pinconf_dbg_conf;
 511        const struct pinctrl_map_configs *configs;
 512        char config[MAX_NAME_LEN+1];
 513        bool found = false;
 514        char buf[128];
 515        char *b = &buf[0];
 516        int buf_size;
 517        char *token;
 518        int i;
 519
 520        /* Get userspace string and assure termination */
 521        buf_size = min(count, (sizeof(buf)-1));
 522        if (copy_from_user(buf, user_buf, buf_size))
 523                return -EFAULT;
 524        buf[buf_size] = 0;
 525
 526        /*
 527         * need to parse entry and extract parameters:
 528         * modify configs_pin devicename state pinname newvalue
 529         */
 530
 531        /* Get arg: 'modify' */
 532        token = strsep(&b, " ");
 533        if (!token)
 534                return -EINVAL;
 535        if (strcmp(token, "modify"))
 536                return -EINVAL;
 537
 538        /* Get arg type: "config_pin" type supported so far */
 539        token = strsep(&b, " ");
 540        if (!token)
 541                return -EINVAL;
 542        if (strcmp(token, "config_pin"))
 543                return -EINVAL;
 544        dbg->map_type = PIN_MAP_TYPE_CONFIGS_PIN;
 545
 546        /* get arg 'device_name' */
 547        token = strsep(&b, " ");
 548        if (token == NULL)
 549                return -EINVAL;
 550        if (strlen(token) >= MAX_NAME_LEN)
 551                return -EINVAL;
 552        strncpy(dbg->dev_name, token, MAX_NAME_LEN);
 553
 554        /* get arg 'state_name' */
 555        token = strsep(&b, " ");
 556        if (token == NULL)
 557                return -EINVAL;
 558        if (strlen(token) >= MAX_NAME_LEN)
 559                return -EINVAL;
 560        strncpy(dbg->state_name, token, MAX_NAME_LEN);
 561
 562        /* get arg 'pin_name' */
 563        token = strsep(&b, " ");
 564        if (token == NULL)
 565                return -EINVAL;
 566        if (strlen(token) >= MAX_NAME_LEN)
 567                return -EINVAL;
 568        strncpy(dbg->pin_name, token, MAX_NAME_LEN);
 569
 570        /* get new_value of config' */
 571        token = strsep(&b, " ");
 572        if (token == NULL)
 573                return -EINVAL;
 574        if (strlen(token) >= MAX_NAME_LEN)
 575                return -EINVAL;
 576        strncpy(config, token, MAX_NAME_LEN);
 577
 578        mutex_lock(&pinctrl_maps_mutex);
 579
 580        /* Parse the pinctrl map and look for the selected dev/state/pin */
 581        for_each_maps(maps_node, i, map) {
 582                if (strcmp(map->dev_name, dbg->dev_name))
 583                        continue;
 584                if (map->type != dbg->map_type)
 585                        continue;
 586                if (strcmp(map->name, dbg->state_name))
 587                        continue;
 588
 589                /*  we found the right pin / state, so overwrite config */
 590                if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
 591                        found = true;
 592                        pctldev = get_pinctrl_dev_from_devname(
 593                                        map->ctrl_dev_name);
 594                        configs = &map->data.configs;
 595                        break;
 596                }
 597        }
 598
 599        if (!found) {
 600                count = -EINVAL;
 601                goto exit;
 602        }
 603
 604        if (pctldev)
 605                confops = pctldev->desc->confops;
 606
 607        if (confops && confops->pin_config_dbg_parse_modify) {
 608                for (i = 0; i < configs->num_configs; i++) {
 609                        confops->pin_config_dbg_parse_modify(pctldev,
 610                                                     config,
 611                                                     &configs->configs[i]);
 612                }
 613        }
 614
 615exit:
 616        mutex_unlock(&pinctrl_maps_mutex);
 617
 618        return count;
 619}
 620
 621static int pinconf_dbg_config_open(struct inode *inode, struct file *file)
 622{
 623        return single_open(file, pinconf_dbg_config_print, inode->i_private);
 624}
 625
 626static const struct file_operations pinconf_dbg_pinconfig_fops = {
 627        .open = pinconf_dbg_config_open,
 628        .write = pinconf_dbg_config_write,
 629        .read = seq_read,
 630        .llseek = seq_lseek,
 631        .release = single_release,
 632        .owner = THIS_MODULE,
 633};
 634
 635void pinconf_init_device_debugfs(struct dentry *devroot,
 636                         struct pinctrl_dev *pctldev)
 637{
 638        debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO,
 639                            devroot, pctldev, &pinconf_pins_ops);
 640        debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
 641                            devroot, pctldev, &pinconf_groups_ops);
 642        debugfs_create_file("pinconf-config",  (S_IRUGO | S_IWUSR | S_IWGRP),
 643                            devroot, pctldev, &pinconf_dbg_pinconfig_fops);
 644}
 645
 646#endif
 647
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