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