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_DRIVE_STRENGTH_UA, "output drive strength", "uA", true),
  43         PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec", true),
  44         PCONFDUMP(PIN_CONFIG_INPUT_ENABLE, "input enabled", NULL, false),
  45         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL, false),
  46         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL, false),
  47         PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode", true),
  48         PCONFDUMP(PIN_CONFIG_OUTPUT_ENABLE, "output enabled", NULL, false),
  49         PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level", 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_LOW_POWER_MODE, 0 },
 179         { "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 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-low", PIN_CONFIG_OUTPUT, 0, },
 184         { "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
 185         { "sleep-hardware-state", PIN_CONFIG_SLEEP_HARDWARE_STATE, 0 },
 186         { "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
 187         { "skew-delay", PIN_CONFIG_SKEW_DELAY, 0 },
 188 };
 189
 190 /**
 191  * parse_dt_cfg() - Parse DT pinconf parameters
 192  * @np: DT node
 193  * @params:     Array of describing generic parameters
 194  * @count:      Number of entries in @params
 195  * @cfg:        Array of parsed config options
 196  * @ncfg:       Number of entries in @cfg
 197  *
 198  * Parse the config options described in @params from @np and puts the result
 199  * in @cfg. @cfg does not need to be empty, entries are added beginning at
 200  * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
 201  * needs to have enough memory allocated to hold all possible entries.
 202  */
 203 static void parse_dt_cfg(struct device_node *np,
 204                          const struct pinconf_generic_params *params,
 205                          unsigned int count, unsigned long *cfg,
 206                          unsigned int *ncfg)
 207 {
 208         int i;
 209
 210         for (i = 0; i < count; i++) {
 211                 u32 val;
 212                 int ret;
 213                 const struct pinconf_generic_params *par = &params[i];
 214
 215                 ret = of_property_read_u32(np, par->property, &val);
 216
 217                 /* property not found */
 218                 if (ret == -EINVAL)
 219                         continue;
 220
 221                 /* use default value, when no value is specified */
 222                 if (ret)
 223                         val = par->default_value;
 224
 225                 pr_debug("found %s with value %u\n", par->property, val);
 226                 cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
 227                 (*ncfg)++;
 228         }
 229 }
 230
 231 /**
 232  * pinconf_generic_parse_dt_config()
 233  * parse the config properties into generic pinconfig values.
 234  * @np: node containing the pinconfig properties
 235  * @configs: array with nconfigs entries containing the generic pinconf values
 236  *           must be freed when no longer necessary.
 237  * @nconfigs: umber of configurations
 238  */
 239 int pinconf_generic_parse_dt_config(struct device_node *np,
 240                                     struct pinctrl_dev *pctldev,
 241                                     unsigned long **configs,
 242                                     unsigned int *nconfigs)
 243 {
 244         unsigned long *cfg;
 245         unsigned int max_cfg, ncfg = 0;
 246         int ret;
 247
 248         if (!np)
 249                 return -EINVAL;
 250
 251         /* allocate a temporary array big enough to hold one of each option */
 252         max_cfg = ARRAY_SIZE(dt_params);
 253         if (pctldev)
 254                 max_cfg += pctldev->desc->num_custom_params;
 255         cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
 256         if (!cfg)
 257                 return -ENOMEM;
 258
 259         parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
 260         if (pctldev && pctldev->desc->num_custom_params &&
 261                 pctldev->desc->custom_params)
 262                 parse_dt_cfg(np, pctldev->desc->custom_params,
 263                              pctldev->desc->num_custom_params, cfg, &ncfg);
 264
 265         ret = 0;
 266
 267         /* no configs found at all */
 268         if (ncfg == 0) {
 269                 *configs = NULL;
 270                 *nconfigs = 0;
 271                 goto out;
 272         }
 273
 274         /*
 275          * Now limit the number of configs to the real number of
 276          * found properties.
 277          */
 278         *configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
 279         if (!*configs) {
 280                 ret = -ENOMEM;
 281                 goto out;
 282         }
 283
 284         *nconfigs = ncfg;
 285
 286 out:
 287         kfree(cfg);
 288         return ret;
 289 }
 290
 291 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
 292                 struct device_node *np, struct pinctrl_map **map,
 293                 unsigned *reserved_maps, unsigned *num_maps,
 294                 enum pinctrl_map_type type)
 295 {
 296         int ret;
 297         const char *function;
 298         struct device *dev = pctldev->dev;
 299         unsigned long *configs = NULL;
 300         unsigned num_configs = 0;
 301         unsigned reserve, strings_count;
 302         struct property *prop;
 303         const char *group;
 304         const char *subnode_target_type = "pins";
 305
 306         ret = of_property_count_strings(np, "pins");
 307         if (ret < 0) {
 308                 ret = of_property_count_strings(np, "groups");
 309                 if (ret < 0)
 310                         /* skip this node; may contain config child nodes */
 311                         return 0;
 312                 if (type == PIN_MAP_TYPE_INVALID)
 313                         type = PIN_MAP_TYPE_CONFIGS_GROUP;
 314                 subnode_target_type = "groups";
 315         } else {
 316                 if (type == PIN_MAP_TYPE_INVALID)
 317                         type = PIN_MAP_TYPE_CONFIGS_PIN;
 318         }
 319         strings_count = ret;
 320
 321         ret = of_property_read_string(np, "function", &function);
 322         if (ret < 0) {
 323                 /* EINVAL=missing, which is fine since it's optional */
 324                 if (ret != -EINVAL)
 325                         dev_err(dev, "%pOF: could not parse property function\n",
 326                                 np);
 327                 function = NULL;
 328         }
 329
 330         ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
 331                                               &num_configs);
 332         if (ret < 0) {
 333                 dev_err(dev, "%pOF: could not parse node property\n", np);
 334                 return ret;
 335         }
 336
 337         reserve = 0;
 338         if (function != NULL)
 339                 reserve++;
 340         if (num_configs)
 341                 reserve++;
 342
 343         reserve *= strings_count;
 344
 345         ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
 346                         num_maps, reserve);
 347         if (ret < 0)
 348                 goto exit;
 349
 350         of_property_for_each_string(np, subnode_target_type, prop, group) {
 351                 if (function) {
 352                         ret = pinctrl_utils_add_map_mux(pctldev, map,
 353                                         reserved_maps, num_maps, group,
 354                                         function);
 355                         if (ret < 0)
 356                                 goto exit;
 357                 }
 358
 359                 if (num_configs) {
 360                         ret = pinctrl_utils_add_map_configs(pctldev, map,
 361                                         reserved_maps, num_maps, group, configs,
 362                                         num_configs, type);
 363                         if (ret < 0)
 364                                 goto exit;
 365                 }
 366         }
 367         ret = 0;
 368
 369 exit:
 370         kfree(configs);
 371         return ret;
 372 }
 373 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
 374
 375 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
 376                 struct device_node *np_config, struct pinctrl_map **map,
 377                 unsigned *num_maps, enum pinctrl_map_type type)
 378 {
 379         unsigned reserved_maps;
 380         struct device_node *np;
 381         int ret;
 382
 383         reserved_maps = 0;
 384         *map = NULL;
 385         *num_maps = 0;
 386
 387         ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
 388                                                 &reserved_maps, num_maps, type);
 389         if (ret < 0)
 390                 goto exit;
 391
 392         for_each_available_child_of_node(np_config, np) {
 393                 ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
 394                                         &reserved_maps, num_maps, type);
 395                 if (ret < 0)
 396                         goto exit;
 397         }
 398         return 0;
 399
 400 exit:
 401         pinctrl_utils_free_map(pctldev, *map, *num_maps);
 402         return ret;
 403 }
 404 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
 405
 406 void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
 407                                  struct pinctrl_map *map,
 408                                  unsigned num_maps)
 409 {
 410         pinctrl_utils_free_map(pctldev, map, num_maps);
 411 }
 412 EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
 413
 414 #endif