linux/drivers/pinctrl/pinconf-generic.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Core driver for the generic pin config portions of the pin control subsystem
   4 *
   5 * Copyright (C) 2011 ST-Ericsson SA
   6 * Written on behalf of Linaro for ST-Ericsson
   7 *
   8 * Author: Linus Walleij <linus.walleij@linaro.org>
   9 */
  10
  11#define pr_fmt(fmt) "generic 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/pinctrl/pinctrl.h>
  21#include <linux/pinctrl/pinconf.h>
  22#include <linux/pinctrl/pinconf-generic.h>
  23#include <linux/of.h>
  24#include "core.h"
  25#include "pinconf.h"
  26#include "pinctrl-utils.h"
  27
  28#ifdef CONFIG_DEBUG_FS
  29static const struct pin_config_item conf_items[] = {
  30        PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL, false),
  31        PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL, false),
  32        PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL, false),
  33        PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL, false),
  34        PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
  35                                "input bias pull to pin specific state", NULL, false),
  36        PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL, false),
  37        PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL, false),
  38        PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),
  39        PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),
  40        PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA", true),
  41        PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH_UA, "output drive strength", "uA", true),
  42        PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec", true),
  43        PCONFDUMP(PIN_CONFIG_INPUT_ENABLE, "input enabled", NULL, false),
  44        PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL, false),
  45        PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL, false),
  46        PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode", true),
  47        PCONFDUMP(PIN_CONFIG_OUTPUT_ENABLE, "output enabled", NULL, false),
  48        PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level", true),
  49        PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true),
  50        PCONFDUMP(PIN_CONFIG_SLEEP_HARDWARE_STATE, "sleep hardware state", NULL, false),
  51        PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL, true),
  52        PCONFDUMP(PIN_CONFIG_SKEW_DELAY, "skew delay", NULL, true),
  53};
  54
  55static void pinconf_generic_dump_one(struct pinctrl_dev *pctldev,
  56                                     struct seq_file *s, const char *gname,
  57                                     unsigned pin,
  58                                     const struct pin_config_item *items,
  59                                     int nitems, int *print_sep)
  60{
  61        int i;
  62
  63        for (i = 0; i < nitems; i++) {
  64                unsigned long config;
  65                int ret;
  66
  67                /* We want to check out this parameter */
  68                config = pinconf_to_config_packed(items[i].param, 0);
  69                if (gname)
  70                        ret = pin_config_group_get(dev_name(pctldev->dev),
  71                                                   gname, &config);
  72                else
  73                        ret = pin_config_get_for_pin(pctldev, pin, &config);
  74                /* These are legal errors */
  75                if (ret == -EINVAL || ret == -ENOTSUPP)
  76                        continue;
  77                if (ret) {
  78                        seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
  79                        continue;
  80                }
  81                /* comma between multiple configs */
  82                if (*print_sep)
  83                        seq_puts(s, ", ");
  84                *print_sep = 1;
  85                seq_puts(s, items[i].display);
  86                /* Print unit if available */
  87                if (items[i].has_arg) {
  88                        seq_printf(s, " (%u",
  89                                   pinconf_to_config_argument(config));
  90                        if (items[i].format)
  91                                seq_printf(s, " %s)", items[i].format);
  92                        else
  93                                seq_puts(s, ")");
  94                }
  95        }
  96}
  97
  98/**
  99 * pinconf_generic_dump_pins - Print information about pin or group of pins
 100 * @pctldev:    Pincontrol device
 101 * @s:          File to print to
 102 * @gname:      Group name specifying pins
 103 * @pin:        Pin number specyfying pin
 104 *
 105 * Print the pinconf configuration for the requested pin(s) to @s. Pins can be
 106 * specified either by pin using @pin or by group using @gname. Only one needs
 107 * to be specified the other can be NULL/0.
 108 */
 109void pinconf_generic_dump_pins(struct pinctrl_dev *pctldev, struct seq_file *s,
 110                               const char *gname, unsigned pin)
 111{
 112        const struct pinconf_ops *ops = pctldev->desc->confops;
 113        int print_sep = 0;
 114
 115        if (!ops->is_generic)
 116                return;
 117
 118        /* generic parameters */
 119        pinconf_generic_dump_one(pctldev, s, gname, pin, conf_items,
 120                                 ARRAY_SIZE(conf_items), &print_sep);
 121        /* driver-specific parameters */
 122        if (pctldev->desc->num_custom_params &&
 123            pctldev->desc->custom_conf_items)
 124                pinconf_generic_dump_one(pctldev, s, gname, pin,
 125                                         pctldev->desc->custom_conf_items,
 126                                         pctldev->desc->num_custom_params,
 127                                         &print_sep);
 128}
 129
 130void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
 131                                 struct seq_file *s, unsigned long config)
 132{
 133        int i;
 134
 135        for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
 136                if (pinconf_to_config_param(config) != conf_items[i].param)
 137                        continue;
 138                seq_printf(s, "%s: 0x%x", conf_items[i].display,
 139                           pinconf_to_config_argument(config));
 140        }
 141
 142        if (!pctldev->desc->num_custom_params ||
 143            !pctldev->desc->custom_conf_items)
 144                return;
 145
 146        for (i = 0; i < pctldev->desc->num_custom_params; i++) {
 147                if (pinconf_to_config_param(config) !=
 148                    pctldev->desc->custom_conf_items[i].param)
 149                        continue;
 150                seq_printf(s, "%s: 0x%x",
 151                                pctldev->desc->custom_conf_items[i].display,
 152                                pinconf_to_config_argument(config));
 153        }
 154}
 155EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
 156#endif
 157
 158#ifdef CONFIG_OF
 159static const struct pinconf_generic_params dt_params[] = {
 160        { "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
 161        { "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
 162        { "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
 163        { "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
 164        { "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
 165        { "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
 166        { "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
 167        { "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
 168        { "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
 169        { "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
 170        { "drive-strength-microamp", PIN_CONFIG_DRIVE_STRENGTH_UA, 0 },
 171        { "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
 172        { "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
 173        { "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
 174        { "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
 175        { "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
 176        { "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
 177        { "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
 178        { "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
 179        { "output-disable", PIN_CONFIG_OUTPUT_ENABLE, 0 },
 180        { "output-enable", PIN_CONFIG_OUTPUT_ENABLE, 1 },
 181        { "output-high", PIN_CONFIG_OUTPUT, 1, },
 182        { "output-low", PIN_CONFIG_OUTPUT, 0, },
 183        { "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
 184        { "sleep-hardware-state", PIN_CONFIG_SLEEP_HARDWARE_STATE, 0 },
 185        { "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
 186        { "skew-delay", PIN_CONFIG_SKEW_DELAY, 0 },
 187};
 188
 189/**
 190 * parse_dt_cfg() - Parse DT pinconf parameters
 191 * @np: DT node
 192 * @params:     Array of describing generic parameters
 193 * @count:      Number of entries in @params
 194 * @cfg:        Array of parsed config options
 195 * @ncfg:       Number of entries in @cfg
 196 *
 197 * Parse the config options described in @params from @np and puts the result
 198 * in @cfg. @cfg does not need to be empty, entries are added beginning at
 199 * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
 200 * needs to have enough memory allocated to hold all possible entries.
 201 */
 202static void parse_dt_cfg(struct device_node *np,
 203                         const struct pinconf_generic_params *params,
 204                         unsigned int count, unsigned long *cfg,
 205                         unsigned int *ncfg)
 206{
 207        int i;
 208
 209        for (i = 0; i < count; i++) {
 210                u32 val;
 211                int ret;
 212                const struct pinconf_generic_params *par = &params[i];
 213
 214                ret = of_property_read_u32(np, par->property, &val);
 215
 216                /* property not found */
 217                if (ret == -EINVAL)
 218                        continue;
 219
 220                /* use default value, when no value is specified */
 221                if (ret)
 222                        val = par->default_value;
 223
 224                pr_debug("found %s with value %u\n", par->property, val);
 225                cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
 226                (*ncfg)++;
 227        }
 228}
 229
 230/**
 231 * pinconf_generic_parse_dt_config()
 232 * parse the config properties into generic pinconfig values.
 233 * @np: node containing the pinconfig properties
 234 * @configs: array with nconfigs entries containing the generic pinconf values
 235 *           must be freed when no longer necessary.
 236 * @nconfigs: umber of configurations
 237 */
 238int pinconf_generic_parse_dt_config(struct device_node *np,
 239                                    struct pinctrl_dev *pctldev,
 240                                    unsigned long **configs,
 241                                    unsigned int *nconfigs)
 242{
 243        unsigned long *cfg;
 244        unsigned int max_cfg, ncfg = 0;
 245        int ret;
 246
 247        if (!np)
 248                return -EINVAL;
 249
 250        /* allocate a temporary array big enough to hold one of each option */
 251        max_cfg = ARRAY_SIZE(dt_params);
 252        if (pctldev)
 253                max_cfg += pctldev->desc->num_custom_params;
 254        cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
 255        if (!cfg)
 256                return -ENOMEM;
 257
 258        parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
 259        if (pctldev && pctldev->desc->num_custom_params &&
 260                pctldev->desc->custom_params)
 261                parse_dt_cfg(np, pctldev->desc->custom_params,
 262                             pctldev->desc->num_custom_params, cfg, &ncfg);
 263
 264        ret = 0;
 265
 266        /* no configs found at all */
 267        if (ncfg == 0) {
 268                *configs = NULL;
 269                *nconfigs = 0;
 270                goto out;
 271        }
 272
 273        /*
 274         * Now limit the number of configs to the real number of
 275         * found properties.
 276         */
 277        *configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
 278        if (!*configs) {
 279                ret = -ENOMEM;
 280                goto out;
 281        }
 282
 283        *nconfigs = ncfg;
 284
 285out:
 286        kfree(cfg);
 287        return ret;
 288}
 289EXPORT_SYMBOL_GPL(pinconf_generic_parse_dt_config);
 290
 291int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
 292                struct device_node *np, struct pinctrl_map **map,
 293                unsigned *reserved_maps, unsigned *num_maps,
 294                enum pinctrl_map_type type)
 295{
 296        int ret;
 297        const char *function;
 298        struct device *dev = pctldev->dev;
 299        unsigned long *configs = NULL;
 300        unsigned num_configs = 0;
 301        unsigned reserve, strings_count;
 302        struct property *prop;
 303        const char *group;
 304        const char *subnode_target_type = "pins";
 305
 306        ret = of_property_count_strings(np, "pins");
 307        if (ret < 0) {
 308                ret = of_property_count_strings(np, "groups");
 309                if (ret < 0)
 310                        /* skip this node; may contain config child nodes */
 311                        return 0;
 312                if (type == PIN_MAP_TYPE_INVALID)
 313                        type = PIN_MAP_TYPE_CONFIGS_GROUP;
 314                subnode_target_type = "groups";
 315        } else {
 316                if (type == PIN_MAP_TYPE_INVALID)
 317                        type = PIN_MAP_TYPE_CONFIGS_PIN;
 318        }
 319        strings_count = ret;
 320
 321        ret = of_property_read_string(np, "function", &function);
 322        if (ret < 0) {
 323                /* EINVAL=missing, which is fine since it's optional */
 324                if (ret != -EINVAL)
 325                        dev_err(dev, "%pOF: could not parse property function\n",
 326                                np);
 327                function = NULL;
 328        }
 329
 330        ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
 331                                              &num_configs);
 332        if (ret < 0) {
 333                dev_err(dev, "%pOF: could not parse node property\n", np);
 334                return ret;
 335        }
 336
 337        reserve = 0;
 338        if (function != NULL)
 339                reserve++;
 340        if (num_configs)
 341                reserve++;
 342
 343        reserve *= strings_count;
 344
 345        ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
 346                        num_maps, reserve);
 347        if (ret < 0)
 348                goto exit;
 349
 350        of_property_for_each_string(np, subnode_target_type, prop, group) {
 351                if (function) {
 352                        ret = pinctrl_utils_add_map_mux(pctldev, map,
 353                                        reserved_maps, num_maps, group,
 354                                        function);
 355                        if (ret < 0)
 356                                goto exit;
 357                }
 358
 359                if (num_configs) {
 360                        ret = pinctrl_utils_add_map_configs(pctldev, map,
 361                                        reserved_maps, num_maps, group, configs,
 362                                        num_configs, type);
 363                        if (ret < 0)
 364                                goto exit;
 365                }
 366        }
 367        ret = 0;
 368
 369exit:
 370        kfree(configs);
 371        return ret;
 372}
 373EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
 374
 375int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
 376                struct device_node *np_config, struct pinctrl_map **map,
 377                unsigned *num_maps, enum pinctrl_map_type type)
 378{
 379        unsigned reserved_maps;
 380        struct device_node *np;
 381        int ret;
 382
 383        reserved_maps = 0;
 384        *map = NULL;
 385        *num_maps = 0;
 386
 387        ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
 388                                                &reserved_maps, num_maps, type);
 389        if (ret < 0)
 390                goto exit;
 391
 392        for_each_available_child_of_node(np_config, np) {
 393                ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
 394                                        &reserved_maps, num_maps, type);
 395                if (ret < 0)
 396                        goto exit;
 397        }
 398        return 0;
 399
 400exit:
 401        pinctrl_utils_free_map(pctldev, *map, *num_maps);
 402        return ret;
 403}
 404EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
 405
 406void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
 407                                 struct pinctrl_map *map,
 408                                 unsigned num_maps)
 409{
 410        pinctrl_utils_free_map(pctldev, map, num_maps);
 411}
 412EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
 413
 414#endif
 415