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