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