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