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