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
  30 static 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_ENABLE, "output enabled", NULL, false),
  48         PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level", true),
  49         PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true),
  50         PCONFDUMP(PIN_CONFIG_SLEEP_HARDWARE_STATE, "sleep hardware state", NULL, false),
  51         PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", 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 };
 185
 186 /**
 187  * parse_dt_cfg() - Parse DT pinconf parameters
 188  * @np: DT node
 189  * @params:     Array of describing generic parameters
 190  * @count:      Number of entries in @params
 191  * @cfg:        Array of parsed config options
 192  * @ncfg:       Number of entries in @cfg
 193  *
 194  * Parse the config options described in @params from @np and puts the result
 195  * in @cfg. @cfg does not need to be empty, entries are added beginning at
 196  * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
 197  * needs to have enough memory allocated to hold all possible entries.
 198  */
 199 static void parse_dt_cfg(struct device_node *np,
 200                          const struct pinconf_generic_params *params,
 201                          unsigned int count, unsigned long *cfg,
 202                          unsigned int *ncfg)
 203 {
 204         int i;
 205
 206         for (i = 0; i < count; i++) {
 207                 u32 val;
 208                 int ret;
 209                 const struct pinconf_generic_params *par = &params[i];
 210
 211                 ret = of_property_read_u32(np, par->property, &val);
 212
 213                 /* property not found */
 214                 if (ret == -EINVAL)
 215                         continue;
 216
 217                 /* use default value, when no value is specified */
 218                 if (ret)
 219                         val = par->default_value;
 220
 221                 pr_debug("found %s with value %u\n", par->property, val);
 222                 cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
 223                 (*ncfg)++;
 224         }
 225 }
 226
 227 /**
 228  * pinconf_generic_parse_dt_config()
 229  * parse the config properties into generic pinconfig values.
 230  * @np: node containing the pinconfig properties
 231  * @configs: array with nconfigs entries containing the generic pinconf values
 232  *           must be freed when no longer necessary.
 233  * @nconfigs: umber of configurations
 234  */
 235 int pinconf_generic_parse_dt_config(struct device_node *np,
 236                                     struct pinctrl_dev *pctldev,
 237                                     unsigned long **configs,
 238                                     unsigned int *nconfigs)
 239 {
 240         unsigned long *cfg;
 241         unsigned int max_cfg, ncfg = 0;
 242         int ret;
 243
 244         if (!np)
 245                 return -EINVAL;
 246
 247         /* allocate a temporary array big enough to hold one of each option */
 248         max_cfg = ARRAY_SIZE(dt_params);
 249         if (pctldev)
 250                 max_cfg += pctldev->desc->num_custom_params;
 251         cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
 252         if (!cfg)
 253                 return -ENOMEM;
 254
 255         parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
 256         if (pctldev && pctldev->desc->num_custom_params &&
 257                 pctldev->desc->custom_params)
 258                 parse_dt_cfg(np, pctldev->desc->custom_params,
 259                              pctldev->desc->num_custom_params, cfg, &ncfg);
 260
 261         ret = 0;
 262
 263         /* no configs found at all */
 264         if (ncfg == 0) {
 265                 *configs = NULL;
 266                 *nconfigs = 0;
 267                 goto out;
 268         }
 269
 270         /*
 271          * Now limit the number of configs to the real number of
 272          * found properties.
 273          */
 274         *configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
 275         if (!*configs) {
 276                 ret = -ENOMEM;
 277                 goto out;
 278         }
 279
 280         *nconfigs = ncfg;
 281
 282 out:
 283         kfree(cfg);
 284         return ret;
 285 }
 286
 287 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
 288                 struct device_node *np, struct pinctrl_map **map,
 289                 unsigned *reserved_maps, unsigned *num_maps,
 290                 enum pinctrl_map_type type)
 291 {
 292         int ret;
 293         const char *function;
 294         struct device *dev = pctldev->dev;
 295         unsigned long *configs = NULL;
 296         unsigned num_configs = 0;
 297         unsigned reserve, strings_count;
 298         struct property *prop;
 299         const char *group;
 300         const char *subnode_target_type = "pins";
 301
 302         ret = of_property_count_strings(np, "pins");
 303         if (ret < 0) {
 304                 ret = of_property_count_strings(np, "groups");
 305                 if (ret < 0)
 306                         /* skip this node; may contain config child nodes */
 307                         return 0;
 308                 if (type == PIN_MAP_TYPE_INVALID)
 309                         type = PIN_MAP_TYPE_CONFIGS_GROUP;
 310                 subnode_target_type = "groups";
 311         } else {
 312                 if (type == PIN_MAP_TYPE_INVALID)
 313                         type = PIN_MAP_TYPE_CONFIGS_PIN;
 314         }
 315         strings_count = ret;
 316
 317         ret = of_property_read_string(np, "function", &function);
 318         if (ret < 0) {
 319                 /* EINVAL=missing, which is fine since it's optional */
 320                 if (ret != -EINVAL)
 321                         dev_err(dev, "%pOF: could not parse property function\n",
 322                                 np);
 323                 function = NULL;
 324         }
 325
 326         ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
 327                                               &num_configs);
 328         if (ret < 0) {
 329                 dev_err(dev, "%pOF: could not parse node property\n", np);
 330                 return ret;
 331         }
 332
 333         reserve = 0;
 334         if (function != NULL)
 335                 reserve++;
 336         if (num_configs)
 337                 reserve++;
 338
 339         reserve *= strings_count;
 340
 341         ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
 342                         num_maps, reserve);
 343         if (ret < 0)
 344                 goto exit;
 345
 346         of_property_for_each_string(np, subnode_target_type, prop, group) {
 347                 if (function) {
 348                         ret = pinctrl_utils_add_map_mux(pctldev, map,
 349                                         reserved_maps, num_maps, group,
 350                                         function);
 351                         if (ret < 0)
 352                                 goto exit;
 353                 }
 354
 355                 if (num_configs) {
 356                         ret = pinctrl_utils_add_map_configs(pctldev, map,
 357                                         reserved_maps, num_maps, group, configs,
 358                                         num_configs, type);
 359                         if (ret < 0)
 360                                 goto exit;
 361                 }
 362         }
 363         ret = 0;
 364
 365 exit:
 366         kfree(configs);
 367         return ret;
 368 }
 369 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
 370
 371 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
 372                 struct device_node *np_config, struct pinctrl_map **map,
 373                 unsigned *num_maps, enum pinctrl_map_type type)
 374 {
 375         unsigned reserved_maps;
 376         struct device_node *np;
 377         int ret;
 378
 379         reserved_maps = 0;
 380         *map = NULL;
 381         *num_maps = 0;
 382
 383         ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
 384                                                 &reserved_maps, num_maps, type);
 385         if (ret < 0)
 386                 goto exit;
 387
 388         for_each_available_child_of_node(np_config, np) {
 389                 ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
 390                                         &reserved_maps, num_maps, type);
 391                 if (ret < 0)
 392                         goto exit;
 393         }
 394         return 0;
 395
 396 exit:
 397         pinctrl_utils_free_map(pctldev, *map, *num_maps);
 398         return ret;
 399 }
 400 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
 401
 402 void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
 403                                  struct pinctrl_map *map,
 404                                  unsigned num_maps)
 405 {
 406         pinctrl_utils_free_map(pctldev, map, num_maps);
 407 }
 408 EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
 409
 410 #endif