drivers/pinctrl/pinconf-generic.c

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