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/array_size.h>
  14 #include <linux/debugfs.h>
  15 #include <linux/device.h>
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/of.h>
  19 #include <linux/slab.h>
  20 #include <linux/seq_file.h>
  21
  22 #include <linux/pinctrl/pinconf-generic.h>
  23 #include <linux/pinctrl/pinconf.h>
  24 #include <linux/pinctrl/pinctrl.h>
  25
  26 #include "core.h"
  27 #include "pinconf.h"
  28 #include "pinctrl-utils.h"
  29
  30 #ifdef CONFIG_DEBUG_FS
  31 static const struct pin_config_item conf_items[] = {
  32         PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL, false),
  33         PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL, false),
  34         PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL, false),
  35         PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", "ohms", true),
  36         PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
  37                                 "input bias pull to pin specific state", "ohms", true),
  38         PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", "ohms", true),
  39         PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL, false),
  40         PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),
  41         PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),
  42         PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA", true),
  43         PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH_UA, "output drive strength", "uA", true),
  44         PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec", true),
  45         PCONFDUMP(PIN_CONFIG_INPUT_ENABLE, "input enabled", NULL, false),
  46         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL, false),
  47         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL, false),
  48         PCONFDUMP(PIN_CONFIG_MODE_LOW_POWER, "pin low power", "mode", true),
  49         PCONFDUMP(PIN_CONFIG_OUTPUT_ENABLE, "output enabled", NULL, false),
  50         PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level", true),
  51         PCONFDUMP(PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS, "output impedance", "ohms", true),
  52         PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true),
  53         PCONFDUMP(PIN_CONFIG_SLEEP_HARDWARE_STATE, "sleep hardware state", NULL, false),
  54         PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL, true),
  55         PCONFDUMP(PIN_CONFIG_SKEW_DELAY, "skew delay", NULL, true),
  56 };
  57
  58 static void pinconf_generic_dump_one(struct pinctrl_dev *pctldev,
  59                                      struct seq_file *s, const char *gname,
  60                                      unsigned int pin,
  61                                      const struct pin_config_item *items,
  62                                      int nitems, int *print_sep)
  63 {
  64         int i;
  65
  66         for (i = 0; i < nitems; i++) {
  67                 unsigned long config;
  68                 int ret;
  69
  70                 /* We want to check out this parameter */
  71                 config = pinconf_to_config_packed(items[i].param, 0);
  72                 if (gname)
  73                         ret = pin_config_group_get(dev_name(pctldev->dev),
  74                                                    gname, &config);
  75                 else
  76                         ret = pin_config_get_for_pin(pctldev, pin, &config);
  77                 /* These are legal errors */
  78                 if (ret == -EINVAL || ret == -ENOTSUPP)
  79                         continue;
  80                 if (ret) {
  81                         seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
  82                         continue;
  83                 }
  84                 /* comma between multiple configs */
  85                 if (*print_sep)
  86                         seq_puts(s, ", ");
  87                 *print_sep = 1;
  88                 seq_puts(s, items[i].display);
  89                 /* Print unit if available */
  90                 if (items[i].has_arg) {
  91                         seq_printf(s, " (%u",
  92                                    pinconf_to_config_argument(config));
  93                         if (items[i].format)
  94                                 seq_printf(s, " %s)", items[i].format);
  95                         else
  96                                 seq_puts(s, ")");
  97                 }
  98         }
  99 }
 100
 101 /**
 102  * pinconf_generic_dump_pins - Print information about pin or group of pins
 103  * @pctldev:    Pincontrol device
 104  * @s:          File to print to
 105  * @gname:      Group name specifying pins
 106  * @pin:        Pin number specyfying pin
 107  *
 108  * Print the pinconf configuration for the requested pin(s) to @s. Pins can be
 109  * specified either by pin using @pin or by group using @gname. Only one needs
 110  * to be specified the other can be NULL/0.
 111  */
 112 void pinconf_generic_dump_pins(struct pinctrl_dev *pctldev, struct seq_file *s,
 113                                const char *gname, unsigned int pin)
 114 {
 115         const struct pinconf_ops *ops = pctldev->desc->confops;
 116         int print_sep = 0;
 117
 118         if (!ops->is_generic)
 119                 return;
 120
 121         /* generic parameters */
 122         pinconf_generic_dump_one(pctldev, s, gname, pin, conf_items,
 123                                  ARRAY_SIZE(conf_items), &print_sep);
 124         /* driver-specific parameters */
 125         if (pctldev->desc->num_custom_params &&
 126             pctldev->desc->custom_conf_items)
 127                 pinconf_generic_dump_one(pctldev, s, gname, pin,
 128                                          pctldev->desc->custom_conf_items,
 129                                          pctldev->desc->num_custom_params,
 130                                          &print_sep);
 131 }
 132
 133 void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
 134                                  struct seq_file *s, unsigned long config)
 135 {
 136         int i;
 137
 138         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
 139                 if (pinconf_to_config_param(config) != conf_items[i].param)
 140                         continue;
 141                 seq_printf(s, "%s: 0x%x", conf_items[i].display,
 142                            pinconf_to_config_argument(config));
 143         }
 144
 145         if (!pctldev->desc->num_custom_params ||
 146             !pctldev->desc->custom_conf_items)
 147                 return;
 148
 149         for (i = 0; i < pctldev->desc->num_custom_params; i++) {
 150                 if (pinconf_to_config_param(config) !=
 151                     pctldev->desc->custom_conf_items[i].param)
 152                         continue;
 153                 seq_printf(s, "%s: 0x%x",
 154                                 pctldev->desc->custom_conf_items[i].display,
 155                                 pinconf_to_config_argument(config));
 156         }
 157 }
 158 EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
 159 #endif
 160
 161 #ifdef CONFIG_OF
 162 static const struct pinconf_generic_params dt_params[] = {
 163         { "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
 164         { "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
 165         { "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
 166         { "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
 167         { "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
 168         { "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
 169         { "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
 170         { "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
 171         { "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
 172         { "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
 173         { "drive-strength-microamp", PIN_CONFIG_DRIVE_STRENGTH_UA, 0 },
 174         { "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
 175         { "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
 176         { "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
 177         { "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
 178         { "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
 179         { "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
 180         { "low-power-disable", PIN_CONFIG_MODE_LOW_POWER, 0 },
 181         { "low-power-enable", PIN_CONFIG_MODE_LOW_POWER, 1 },
 182         { "output-disable", PIN_CONFIG_OUTPUT_ENABLE, 0 },
 183         { "output-enable", PIN_CONFIG_OUTPUT_ENABLE, 1 },
 184         { "output-high", PIN_CONFIG_OUTPUT, 1, },
 185         { "output-impedance-ohms", PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS, 0 },
 186         { "output-low", PIN_CONFIG_OUTPUT, 0, },
 187         { "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
 188         { "sleep-hardware-state", PIN_CONFIG_SLEEP_HARDWARE_STATE, 0 },
 189         { "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
 190         { "skew-delay", PIN_CONFIG_SKEW_DELAY, 0 },
 191 };
 192
 193 /**
 194  * parse_dt_cfg() - Parse DT pinconf parameters
 195  * @np: DT node
 196  * @params:     Array of describing generic parameters
 197  * @count:      Number of entries in @params
 198  * @cfg:        Array of parsed config options
 199  * @ncfg:       Number of entries in @cfg
 200  *
 201  * Parse the config options described in @params from @np and puts the result
 202  * in @cfg. @cfg does not need to be empty, entries are added beginning at
 203  * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
 204  * needs to have enough memory allocated to hold all possible entries.
 205  */
 206 static void parse_dt_cfg(struct device_node *np,
 207                          const struct pinconf_generic_params *params,
 208                          unsigned int count, unsigned long *cfg,
 209                          unsigned int *ncfg)
 210 {
 211         int i;
 212
 213         for (i = 0; i < count; i++) {
 214                 u32 val;
 215                 int ret;
 216                 const struct pinconf_generic_params *par = &params[i];
 217
 218                 ret = of_property_read_u32(np, par->property, &val);
 219
 220                 /* property not found */
 221                 if (ret == -EINVAL)
 222                         continue;
 223
 224                 /* use default value, when no value is specified */
 225                 if (ret)
 226                         val = par->default_value;
 227
 228                 pr_debug("found %s with value %u\n", par->property, val);
 229                 cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
 230                 (*ncfg)++;
 231         }
 232 }
 233
 234 /**
 235  * pinconf_generic_parse_dt_config()
 236  * parse the config properties into generic pinconfig values.
 237  * @np: node containing the pinconfig properties
 238  * @pctldev: pincontrol device
 239  * @configs: array with nconfigs entries containing the generic pinconf values
 240  *           must be freed when no longer necessary.
 241  * @nconfigs: number of configurations
 242  */
 243 int pinconf_generic_parse_dt_config(struct device_node *np,
 244                                     struct pinctrl_dev *pctldev,
 245                                     unsigned long **configs,
 246                                     unsigned int *nconfigs)
 247 {
 248         unsigned long *cfg;
 249         unsigned int max_cfg, ncfg = 0;
 250         int ret;
 251
 252         if (!np)
 253                 return -EINVAL;
 254
 255         /* allocate a temporary array big enough to hold one of each option */
 256         max_cfg = ARRAY_SIZE(dt_params);
 257         if (pctldev)
 258                 max_cfg += pctldev->desc->num_custom_params;
 259         cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
 260         if (!cfg)
 261                 return -ENOMEM;
 262
 263         parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
 264         if (pctldev && pctldev->desc->num_custom_params &&
 265                 pctldev->desc->custom_params)
 266                 parse_dt_cfg(np, pctldev->desc->custom_params,
 267                              pctldev->desc->num_custom_params, cfg, &ncfg);
 268
 269         ret = 0;
 270
 271         /* no configs found at all */
 272         if (ncfg == 0) {
 273                 *configs = NULL;
 274                 *nconfigs = 0;
 275                 goto out;
 276         }
 277
 278         /*
 279          * Now limit the number of configs to the real number of
 280          * found properties.
 281          */
 282         *configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
 283         if (!*configs) {
 284                 ret = -ENOMEM;
 285                 goto out;
 286         }
 287
 288         *nconfigs = ncfg;
 289
 290 out:
 291         kfree(cfg);
 292         return ret;
 293 }
 294 EXPORT_SYMBOL_GPL(pinconf_generic_parse_dt_config);
 295
 296 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
 297                 struct device_node *np, struct pinctrl_map **map,
 298                 unsigned int *reserved_maps, unsigned int *num_maps,
 299                 enum pinctrl_map_type type)
 300 {
 301         int ret;
 302         const char *function;
 303         struct device *dev = pctldev->dev;
 304         unsigned long *configs = NULL;
 305         unsigned int num_configs = 0;
 306         unsigned int reserve, strings_count;
 307         struct property *prop;
 308         const char *group;
 309         const char *subnode_target_type = "pins";
 310
 311         ret = of_property_count_strings(np, "pins");
 312         if (ret < 0) {
 313                 ret = of_property_count_strings(np, "groups");
 314                 if (ret < 0)
 315                         /* skip this node; may contain config child nodes */
 316                         return 0;
 317                 if (type == PIN_MAP_TYPE_INVALID)
 318                         type = PIN_MAP_TYPE_CONFIGS_GROUP;
 319                 subnode_target_type = "groups";
 320         } else {
 321                 if (type == PIN_MAP_TYPE_INVALID)
 322                         type = PIN_MAP_TYPE_CONFIGS_PIN;
 323         }
 324         strings_count = ret;
 325
 326         ret = of_property_read_string(np, "function", &function);
 327         if (ret < 0) {
 328                 /* EINVAL=missing, which is fine since it's optional */
 329                 if (ret != -EINVAL)
 330                         dev_err(dev, "%pOF: could not parse property function\n",
 331                                 np);
 332                 function = NULL;
 333         }
 334
 335         ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
 336                                               &num_configs);
 337         if (ret < 0) {
 338                 dev_err(dev, "%pOF: could not parse node property\n", np);
 339                 return ret;
 340         }
 341
 342         reserve = 0;
 343         if (function != NULL)
 344                 reserve++;
 345         if (num_configs)
 346                 reserve++;
 347
 348         reserve *= strings_count;
 349
 350         ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
 351                         num_maps, reserve);
 352         if (ret < 0)
 353                 goto exit;
 354
 355         of_property_for_each_string(np, subnode_target_type, prop, group) {
 356                 if (function) {
 357                         ret = pinctrl_utils_add_map_mux(pctldev, map,
 358                                         reserved_maps, num_maps, group,
 359                                         function);
 360                         if (ret < 0)
 361                                 goto exit;
 362                 }
 363
 364                 if (num_configs) {
 365                         ret = pinctrl_utils_add_map_configs(pctldev, map,
 366                                         reserved_maps, num_maps, group, configs,
 367                                         num_configs, type);
 368                         if (ret < 0)
 369                                 goto exit;
 370                 }
 371         }
 372         ret = 0;
 373
 374 exit:
 375         kfree(configs);
 376         return ret;
 377 }
 378 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
 379
 380 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
 381                 struct device_node *np_config, struct pinctrl_map **map,
 382                 unsigned int *num_maps, enum pinctrl_map_type type)
 383 {
 384         unsigned int reserved_maps;
 385         struct device_node *np;
 386         int ret;
 387
 388         reserved_maps = 0;
 389         *map = NULL;
 390         *num_maps = 0;
 391
 392         ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
 393                                                 &reserved_maps, num_maps, type);
 394         if (ret < 0)
 395                 goto exit;
 396
 397         for_each_available_child_of_node(np_config, np) {
 398                 ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
 399                                         &reserved_maps, num_maps, type);
 400                 if (ret < 0) {
 401                         of_node_put(np);
 402                         goto exit;
 403                 }
 404         }
 405         return 0;
 406
 407 exit:
 408         pinctrl_utils_free_map(pctldev, *map, *num_maps);
 409         return ret;
 410 }
 411 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
 412
 413 void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
 414                                  struct pinctrl_map *map,
 415                                  unsigned int num_maps)
 416 {
 417         pinctrl_utils_free_map(pctldev, map, num_maps);
 418 }
 419 EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
 420
 421 #endif