LXR linux/drivers/pinctrl/pinconf-generic.c

   1/*
   2 * Core driver for the generic 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
  12#define pr_fmt(fmt) "generic pinconfig core: " fmt
  13
  14#include <linux/kernel.h>
  15#include <linux/module.h>
  16#include <linux/init.h>
  17#include <linux/device.h>
  18#include <linux/slab.h>
  19#include <linux/debugfs.h>
  20#include <linux/seq_file.h>
  21#include <linux/pinctrl/pinctrl.h>
  22#include <linux/pinctrl/pinconf.h>
  23#include <linux/pinctrl/pinconf-generic.h>
  24#include <linux/of.h>
  25#include "core.h"
  26#include "pinconf.h"
  27#include "pinctrl-utils.h"
  28
  29#ifdef CONFIG_DEBUG_FS
  30static const struct pin_config_item conf_items[] = {
  31        PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL, false),
  32        PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL, false),
  33        PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL, false),
  34        PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL, false),
  35        PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
  36                                "input bias pull to pin specific state", NULL, false),
  37        PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL, false),
  38        PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL, false),
  39        PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),
  40        PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),
  41        PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA", 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, "pin output", "level", true),
  48        PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true),
  49        PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL, true),
  50};
  51
  52static void pinconf_generic_dump_one(struct pinctrl_dev *pctldev,
  53                                     struct seq_file *s, const char *gname,
  54                                     unsigned pin,
  55                                     const struct pin_config_item *items,
  56                                     int nitems, int *print_sep)
  57{
  58        int i;
  59
  60        for (i = 0; i < nitems; i++) {
  61                unsigned long config;
  62                int ret;
  63
  64                /* We want to check out this parameter */
  65                config = pinconf_to_config_packed(items[i].param, 0);
  66                if (gname)
  67                        ret = pin_config_group_get(dev_name(pctldev->dev),
  68                                                   gname, &config);
  69                else
  70                        ret = pin_config_get_for_pin(pctldev, pin, &config);
  71                /* These are legal errors */
  72                if (ret == -EINVAL || ret == -ENOTSUPP)
  73                        continue;
  74                if (ret) {
  75                        seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
  76                        continue;
  77                }
  78                /* comma between multiple configs */
  79                if (*print_sep)
  80                        seq_puts(s, ", ");
  81                *print_sep = 1;
  82                seq_puts(s, items[i].display);
  83                /* Print unit if available */
  84                if (items[i].has_arg) {
  85                        seq_printf(s, " (%u",
  86                                   pinconf_to_config_argument(config));
  87                        if (items[i].format)
  88                                seq_printf(s, " %s)", items[i].format);
  89                        else
  90                                seq_puts(s, ")");
  91                }
  92        }
  93}
  94
  95/**
  96 * pinconf_generic_dump_pins - Print information about pin or group of pins
  97 * @pctldev:    Pincontrol device
  98 * @s:          File to print to
  99 * @gname:      Group name specifying pins
 100 * @pin:        Pin number specyfying pin
 101 *
 102 * Print the pinconf configuration for the requested pin(s) to @s. Pins can be
 103 * specified either by pin using @pin or by group using @gname. Only one needs
 104 * to be specified the other can be NULL/0.
 105 */
 106void pinconf_generic_dump_pins(struct pinctrl_dev *pctldev, struct seq_file *s,
 107                               const char *gname, unsigned pin)
 108{
 109        const struct pinconf_ops *ops = pctldev->desc->confops;
 110        int print_sep = 0;
 111
 112        if (!ops->is_generic)
 113                return;
 114
 115        /* generic parameters */
 116        pinconf_generic_dump_one(pctldev, s, gname, pin, conf_items,
 117                                 ARRAY_SIZE(conf_items), &print_sep);
 118        /* driver-specific parameters */
 119        if (pctldev->desc->num_custom_params &&
 120            pctldev->desc->custom_conf_items)
 121                pinconf_generic_dump_one(pctldev, s, gname, pin,
 122                                         pctldev->desc->custom_conf_items,
 123                                         pctldev->desc->num_custom_params,
 124                                         &print_sep);
 125}
 126
 127void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
 128                                 struct seq_file *s, unsigned long config)
 129{
 130        int i;
 131
 132        for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
 133                if (pinconf_to_config_param(config) != conf_items[i].param)
 134                        continue;
 135                seq_printf(s, "%s: 0x%x", conf_items[i].display,
 136                           pinconf_to_config_argument(config));
 137        }
 138
 139        if (!pctldev->desc->num_custom_params ||
 140            !pctldev->desc->custom_conf_items)
 141                return;
 142
 143        for (i = 0; i < pctldev->desc->num_custom_params; i++) {
 144                if (pinconf_to_config_param(config) !=
 145                    pctldev->desc->custom_conf_items[i].param)
 146                        continue;
 147                seq_printf(s, "%s: 0x%x",
 148                                pctldev->desc->custom_conf_items[i].display,
 149                                pinconf_to_config_argument(config));
 150        }
 151}
 152EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
 153#endif
 154
 155#ifdef CONFIG_OF
 156static const struct pinconf_generic_params dt_params[] = {
 157        { "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
 158        { "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
 159        { "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
 160        { "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
 161        { "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
 162        { "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
 163        { "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
 164        { "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
 165        { "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
 166        { "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
 167        { "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
 168        { "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
 169        { "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
 170        { "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
 171        { "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
 172        { "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
 173        { "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
 174        { "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
 175        { "output-high", PIN_CONFIG_OUTPUT, 1, },
 176        { "output-low", PIN_CONFIG_OUTPUT, 0, },
 177        { "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
 178        { "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
 179};
 180
 181/**
 182 * parse_dt_cfg() - Parse DT pinconf parameters
 183 * @np: DT node
 184 * @params:     Array of describing generic parameters
 185 * @count:      Number of entries in @params
 186 * @cfg:        Array of parsed config options
 187 * @ncfg:       Number of entries in @cfg
 188 *
 189 * Parse the config options described in @params from @np and puts the result
 190 * in @cfg. @cfg does not need to be empty, entries are added beggining at
 191 * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
 192 * needs to have enough memory allocated to hold all possible entries.
 193 */
 194static void parse_dt_cfg(struct device_node *np,
 195                         const struct pinconf_generic_params *params,
 196                         unsigned int count, unsigned long *cfg,
 197                         unsigned int *ncfg)
 198{
 199        int i;
 200
 201        for (i = 0; i < count; i++) {
 202                u32 val;
 203                int ret;
 204                const struct pinconf_generic_params *par = &params[i];
 205
 206                ret = of_property_read_u32(np, par->property, &val);
 207
 208                /* property not found */
 209                if (ret == -EINVAL)
 210                        continue;
 211
 212                /* use default value, when no value is specified */
 213                if (ret)
 214                        val = par->default_value;
 215
 216                pr_debug("found %s with value %u\n", par->property, val);
 217                cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
 218                (*ncfg)++;
 219        }
 220}
 221
 222/**
 223 * pinconf_generic_parse_dt_config()
 224 * parse the config properties into generic pinconfig values.
 225 * @np: node containing the pinconfig properties
 226 * @configs: array with nconfigs entries containing the generic pinconf values
 227 *           must be freed when no longer necessary.
 228 * @nconfigs: umber of configurations
 229 */
 230int pinconf_generic_parse_dt_config(struct device_node *np,
 231                                    struct pinctrl_dev *pctldev,
 232                                    unsigned long **configs,
 233                                    unsigned int *nconfigs)
 234{
 235        unsigned long *cfg;
 236        unsigned int max_cfg, ncfg = 0;
 237        int ret;
 238
 239        if (!np)
 240                return -EINVAL;
 241
 242        /* allocate a temporary array big enough to hold one of each option */
 243        max_cfg = ARRAY_SIZE(dt_params);
 244        if (pctldev)
 245                max_cfg += pctldev->desc->num_custom_params;
 246        cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
 247        if (!cfg)
 248                return -ENOMEM;
 249
 250        parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
 251        if (pctldev && pctldev->desc->num_custom_params &&
 252                pctldev->desc->custom_params)
 253                parse_dt_cfg(np, pctldev->desc->custom_params,
 254                             pctldev->desc->num_custom_params, cfg, &ncfg);
 255
 256        ret = 0;
 257
 258        /* no configs found at all */
 259        if (ncfg == 0) {
 260                *configs = NULL;
 261                *nconfigs = 0;
 262                goto out;
 263        }
 264
 265        /*
 266         * Now limit the number of configs to the real number of
 267         * found properties.
 268         */
 269        *configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
 270        if (!*configs) {
 271                ret = -ENOMEM;
 272                goto out;
 273        }
 274
 275        *nconfigs = ncfg;
 276
 277out:
 278        kfree(cfg);
 279        return ret;
 280}
 281
 282int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
 283                struct device_node *np, struct pinctrl_map **map,
 284                unsigned *reserved_maps, unsigned *num_maps,
 285                enum pinctrl_map_type type)
 286{
 287        int ret;
 288        const char *function;
 289        struct device *dev = pctldev->dev;
 290        unsigned long *configs = NULL;
 291        unsigned num_configs = 0;
 292        unsigned reserve, strings_count;
 293        struct property *prop;
 294        const char *group;
 295        const char *subnode_target_type = "pins";
 296
 297        ret = of_property_count_strings(np, "pins");
 298        if (ret < 0) {
 299                ret = of_property_count_strings(np, "groups");
 300                if (ret < 0)
 301                        /* skip this node; may contain config child nodes */
 302                        return 0;
 303                if (type == PIN_MAP_TYPE_INVALID)
 304                        type = PIN_MAP_TYPE_CONFIGS_GROUP;
 305                subnode_target_type = "groups";
 306        } else {
 307                if (type == PIN_MAP_TYPE_INVALID)
 308                        type = PIN_MAP_TYPE_CONFIGS_PIN;
 309        }
 310        strings_count = ret;
 311
 312        ret = of_property_read_string(np, "function", &function);
 313        if (ret < 0) {
 314                /* EINVAL=missing, which is fine since it's optional */
 315                if (ret != -EINVAL)
 316                        dev_err(dev, "%s: could not parse property function\n",
 317                                of_node_full_name(np));
 318                function = NULL;
 319        }
 320
 321        ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
 322                                              &num_configs);
 323        if (ret < 0) {
 324                dev_err(dev, "%s: could not parse node property\n",
 325                        of_node_full_name(np));
 326                return ret;
 327        }
 328
 329        reserve = 0;
 330        if (function != NULL)
 331                reserve++;
 332        if (num_configs)
 333                reserve++;
 334
 335        reserve *= strings_count;
 336
 337        ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
 338                        num_maps, reserve);
 339        if (ret < 0)
 340                goto exit;
 341
 342        of_property_for_each_string(np, subnode_target_type, prop, group) {
 343                if (function) {
 344                        ret = pinctrl_utils_add_map_mux(pctldev, map,
 345                                        reserved_maps, num_maps, group,
 346                                        function);
 347                        if (ret < 0)
 348                                goto exit;
 349                }
 350
 351                if (num_configs) {
 352                        ret = pinctrl_utils_add_map_configs(pctldev, map,
 353                                        reserved_maps, num_maps, group, configs,
 354                                        num_configs, type);
 355                        if (ret < 0)
 356                                goto exit;
 357                }
 358        }
 359        ret = 0;
 360
 361exit:
 362        kfree(configs);
 363        return ret;
 364}
 365EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
 366
 367int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
 368                struct device_node *np_config, struct pinctrl_map **map,
 369                unsigned *num_maps, enum pinctrl_map_type type)
 370{
 371        unsigned reserved_maps;
 372        struct device_node *np;
 373        int ret;
 374
 375        reserved_maps = 0;
 376        *map = NULL;
 377        *num_maps = 0;
 378
 379        ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
 380                                                &reserved_maps, num_maps, type);
 381        if (ret < 0)
 382                goto exit;
 383
 384        for_each_child_of_node(np_config, np) {
 385                ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
 386                                        &reserved_maps, num_maps, type);
 387                if (ret < 0)
 388                        goto exit;
 389        }
 390        return 0;
 391
 392exit:
 393        pinctrl_utils_free_map(pctldev, *map, *num_maps);
 394        return ret;
 395}
 396EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
 397
 398void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
 399                                 struct pinctrl_map *map,
 400                                 unsigned num_maps)
 401{
 402        pinctrl_utils_free_map(pctldev, map, num_maps);
 403}
 404EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
 405
 406#endif
 407