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