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_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        { "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
 171        { "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
 172        { "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
 173        { "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
 174        { "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
 175        { "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
 176        { "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
 177        { "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
 178        { "output-disable", PIN_CONFIG_OUTPUT_ENABLE, 0 },
 179        { "output-enable", PIN_CONFIG_OUTPUT_ENABLE, 1 },
 180        { "output-high", PIN_CONFIG_OUTPUT, 1, },
 181        { "output-low", PIN_CONFIG_OUTPUT, 0, },
 182        { "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
 183        { "sleep-hardware-state", PIN_CONFIG_SLEEP_HARDWARE_STATE, 0 },
 184        { "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
 185        { "skew-delay", PIN_CONFIG_SKEW_DELAY, 0 },
 186};
 187
 188/**
 189 * parse_dt_cfg() - Parse DT pinconf parameters
 190 * @np: DT node
 191 * @params:     Array of describing generic parameters
 192 * @count:      Number of entries in @params
 193 * @cfg:        Array of parsed config options
 194 * @ncfg:       Number of entries in @cfg
 195 *
 196 * Parse the config options described in @params from @np and puts the result
 197 * in @cfg. @cfg does not need to be empty, entries are added beginning at
 198 * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
 199 * needs to have enough memory allocated to hold all possible entries.
 200 */
 201static void parse_dt_cfg(struct device_node *np,
 202                         const struct pinconf_generic_params *params,
 203                         unsigned int count, unsigned long *cfg,
 204                         unsigned int *ncfg)
 205{
 206        int i;
 207
 208        for (i = 0; i < count; i++) {
 209                u32 val;
 210                int ret;
 211                const struct pinconf_generic_params *par = &params[i];
 212
 213                ret = of_property_read_u32(np, par->property, &val);
 214
 215                /* property not found */
 216                if (ret == -EINVAL)
 217                        continue;
 218
 219                /* use default value, when no value is specified */
 220                if (ret)
 221                        val = par->default_value;
 222
 223                pr_debug("found %s with value %u\n", par->property, val);
 224                cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
 225                (*ncfg)++;
 226        }
 227}
 228
 229/**
 230 * pinconf_generic_parse_dt_config()
 231 * parse the config properties into generic pinconfig values.
 232 * @np: node containing the pinconfig properties
 233 * @configs: array with nconfigs entries containing the generic pinconf values
 234 *           must be freed when no longer necessary.
 235 * @nconfigs: umber of configurations
 236 */
 237int pinconf_generic_parse_dt_config(struct device_node *np,
 238                                    struct pinctrl_dev *pctldev,
 239                                    unsigned long **configs,
 240                                    unsigned int *nconfigs)
 241{
 242        unsigned long *cfg;
 243        unsigned int max_cfg, ncfg = 0;
 244        int ret;
 245
 246        if (!np)
 247                return -EINVAL;
 248
 249        /* allocate a temporary array big enough to hold one of each option */
 250        max_cfg = ARRAY_SIZE(dt_params);
 251        if (pctldev)
 252                max_cfg += pctldev->desc->num_custom_params;
 253        cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
 254        if (!cfg)
 255                return -ENOMEM;
 256
 257        parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
 258        if (pctldev && pctldev->desc->num_custom_params &&
 259                pctldev->desc->custom_params)
 260                parse_dt_cfg(np, pctldev->desc->custom_params,
 261                             pctldev->desc->num_custom_params, cfg, &ncfg);
 262
 263        ret = 0;
 264
 265        /* no configs found at all */
 266        if (ncfg == 0) {
 267                *configs = NULL;
 268                *nconfigs = 0;
 269                goto out;
 270        }
 271
 272        /*
 273         * Now limit the number of configs to the real number of
 274         * found properties.
 275         */
 276        *configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
 277        if (!*configs) {
 278                ret = -ENOMEM;
 279                goto out;
 280        }
 281
 282        *nconfigs = ncfg;
 283
 284out:
 285        kfree(cfg);
 286        return ret;
 287}
 288
 289int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
 290                struct device_node *np, struct pinctrl_map **map,
 291                unsigned *reserved_maps, unsigned *num_maps,
 292                enum pinctrl_map_type type)
 293{
 294        int ret;
 295        const char *function;
 296        struct device *dev = pctldev->dev;
 297        unsigned long *configs = NULL;
 298        unsigned num_configs = 0;
 299        unsigned reserve, strings_count;
 300        struct property *prop;
 301        const char *group;
 302        const char *subnode_target_type = "pins";
 303
 304        ret = of_property_count_strings(np, "pins");
 305        if (ret < 0) {
 306                ret = of_property_count_strings(np, "groups");
 307                if (ret < 0)
 308                        /* skip this node; may contain config child nodes */
 309                        return 0;
 310                if (type == PIN_MAP_TYPE_INVALID)
 311                        type = PIN_MAP_TYPE_CONFIGS_GROUP;
 312                subnode_target_type = "groups";
 313        } else {
 314                if (type == PIN_MAP_TYPE_INVALID)
 315                        type = PIN_MAP_TYPE_CONFIGS_PIN;
 316        }
 317        strings_count = ret;
 318
 319        ret = of_property_read_string(np, "function", &function);
 320        if (ret < 0) {
 321                /* EINVAL=missing, which is fine since it's optional */
 322                if (ret != -EINVAL)
 323                        dev_err(dev, "%pOF: could not parse property function\n",
 324                                np);
 325                function = NULL;
 326        }
 327
 328        ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
 329                                              &num_configs);
 330        if (ret < 0) {
 331                dev_err(dev, "%pOF: could not parse node property\n", np);
 332                return ret;
 333        }
 334
 335        reserve = 0;
 336        if (function != NULL)
 337                reserve++;
 338        if (num_configs)
 339                reserve++;
 340
 341        reserve *= strings_count;
 342
 343        ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
 344                        num_maps, reserve);
 345        if (ret < 0)
 346                goto exit;
 347
 348        of_property_for_each_string(np, subnode_target_type, prop, group) {
 349                if (function) {
 350                        ret = pinctrl_utils_add_map_mux(pctldev, map,
 351                                        reserved_maps, num_maps, group,
 352                                        function);
 353                        if (ret < 0)
 354                                goto exit;
 355                }
 356
 357                if (num_configs) {
 358                        ret = pinctrl_utils_add_map_configs(pctldev, map,
 359                                        reserved_maps, num_maps, group, configs,
 360                                        num_configs, type);
 361                        if (ret < 0)
 362                                goto exit;
 363                }
 364        }
 365        ret = 0;
 366
 367exit:
 368        kfree(configs);
 369        return ret;
 370}
 371EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
 372
 373int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
 374                struct device_node *np_config, struct pinctrl_map **map,
 375                unsigned *num_maps, enum pinctrl_map_type type)
 376{
 377        unsigned reserved_maps;
 378        struct device_node *np;
 379        int ret;
 380
 381        reserved_maps = 0;
 382        *map = NULL;
 383        *num_maps = 0;
 384
 385        ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
 386                                                &reserved_maps, num_maps, type);
 387        if (ret < 0)
 388                goto exit;
 389
 390        for_each_available_child_of_node(np_config, np) {
 391                ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
 392                                        &reserved_maps, num_maps, type);
 393                if (ret < 0)
 394                        goto exit;
 395        }
 396        return 0;
 397
 398exit:
 399        pinctrl_utils_free_map(pctldev, *map, *num_maps);
 400        return ret;
 401}
 402EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
 403
 404void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
 405                                 struct pinctrl_map *map,
 406                                 unsigned num_maps)
 407{
 408        pinctrl_utils_free_map(pctldev, map, num_maps);
 409}
 410EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
 411
 412#endif
 413