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
  31 struct pin_config_item {
  32         const enum pin_config_param param;
  33         const char * const display;
  34         const char * const format;
  35         bool has_arg;
  36 };
  37
  38 #define PCONFDUMP(a, b, c, d) { .param = a, .display = b, .format = c, \
  39                                 .has_arg = d }
  40
  41 static const struct pin_config_item conf_items[] = {
  42         PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL, false),
  43         PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL, false),
  44         PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL, false),
  45         PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL, false),
  46         PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL, false),
  47         PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
  48                                 "input bias pull to pin specific state", NULL, false),
  49         PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),
  50         PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL, false),
  51         PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),
  52         PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA", true),
  53         PCONFDUMP(PIN_CONFIG_INPUT_ENABLE, "input enabled", NULL, false),
  54         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL, false),
  55         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL, false),
  56         PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec", true),
  57         PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true),
  58         PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL, true),
  59         PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode", true),
  60         PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level", true),
  61 };
  62
  63 void pinconf_generic_dump_pin(struct pinctrl_dev *pctldev,
  64                               struct seq_file *s, unsigned pin)
  65 {
  66         const struct pinconf_ops *ops = pctldev->desc->confops;
  67         int i;
  68
  69         if (!ops->is_generic)
  70                 return;
  71
  72         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
  73                 unsigned long config;
  74                 int ret;
  75
  76                 /* We want to check out this parameter */
  77                 config = pinconf_to_config_packed(conf_items[i].param, 0);
  78                 ret = pin_config_get_for_pin(pctldev, pin, &config);
  79                 /* These are legal errors */
  80                 if (ret == -EINVAL || ret == -ENOTSUPP)
  81                         continue;
  82                 if (ret) {
  83                         seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
  84                         continue;
  85                 }
  86                 /* Space between multiple configs */
  87                 seq_puts(s, " ");
  88                 seq_puts(s, conf_items[i].display);
  89                 /* Print unit if available */
  90                 if (conf_items[i].has_arg) {
  91                         seq_printf(s, " (%u",
  92                                    pinconf_to_config_argument(config));
  93                         if (conf_items[i].format)
  94                                 seq_printf(s, " %s)", conf_items[i].format);
  95                         else
  96                                 seq_puts(s, ")");
  97                 }
  98         }
  99 }
 100
 101 void pinconf_generic_dump_group(struct pinctrl_dev *pctldev,
 102                               struct seq_file *s, const char *gname)
 103 {
 104         const struct pinconf_ops *ops = pctldev->desc->confops;
 105         int i;
 106
 107         if (!ops->is_generic)
 108                 return;
 109
 110         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
 111                 unsigned long config;
 112                 int ret;
 113
 114                 /* We want to check out this parameter */
 115                 config = pinconf_to_config_packed(conf_items[i].param, 0);
 116                 ret = pin_config_group_get(dev_name(pctldev->dev), gname,
 117                                            &config);
 118                 /* These are legal errors */
 119                 if (ret == -EINVAL || ret == -ENOTSUPP)
 120                         continue;
 121                 if (ret) {
 122                         seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
 123                         continue;
 124                 }
 125                 /* Space between multiple configs */
 126                 seq_puts(s, " ");
 127                 seq_puts(s, conf_items[i].display);
 128                 /* Print unit if available */
 129                 if (conf_items[i].has_arg) {
 130                         seq_printf(s, " (%u",
 131                                    pinconf_to_config_argument(config));
 132                         if (conf_items[i].format)
 133                                 seq_printf(s, " %s)", conf_items[i].format);
 134                         else
 135                                 seq_puts(s, ")");
 136                 }
 137         }
 138 }
 139
 140 void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
 141                                  struct seq_file *s, unsigned long config)
 142 {
 143         int i;
 144
 145         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
 146                 if (pinconf_to_config_param(config) != conf_items[i].param)
 147                         continue;
 148                 seq_printf(s, "%s: 0x%x", 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 struct pinconf_generic_dt_params {
 157         const char * const property;
 158         enum pin_config_param param;
 159         u32 default_value;
 160 };
 161
 162 static const struct pinconf_generic_dt_params dt_params[] = {
 163         { "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
 164         { "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
 165         { "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
 166         { "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
 167         { "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
 168         { "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
 169         { "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
 170         { "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
 171         { "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
 172         { "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
 173         { "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
 174         { "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
 175         { "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
 176         { "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
 177         { "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
 178         { "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
 179         { "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
 180         { "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
 181         { "output-low", PIN_CONFIG_OUTPUT, 0, },
 182         { "output-high", PIN_CONFIG_OUTPUT, 1, },
 183         { "slew-rate", PIN_CONFIG_SLEW_RATE, 0},
 184 };
 185
 186 /**
 187  * pinconf_generic_parse_dt_config()
 188  * parse the config properties into generic pinconfig values.
 189  * @np: node containing the pinconfig properties
 190  * @configs: array with nconfigs entries containing the generic pinconf values
 191  * @nconfigs: umber of configurations
 192  */
 193 int pinconf_generic_parse_dt_config(struct device_node *np,
 194                                     unsigned long **configs,
 195                                     unsigned int *nconfigs)
 196 {
 197         unsigned long *cfg;
 198         unsigned int ncfg = 0;
 199         int ret;
 200         int i;
 201         u32 val;
 202
 203         if (!np)
 204                 return -EINVAL;
 205
 206         /* allocate a temporary array big enough to hold one of each option */
 207         cfg = kzalloc(sizeof(*cfg) * ARRAY_SIZE(dt_params), GFP_KERNEL);
 208         if (!cfg)
 209                 return -ENOMEM;
 210
 211         for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
 212                 const struct pinconf_generic_dt_params *par = &dt_params[i];
 213                 ret = of_property_read_u32(np, par->property, &val);
 214
 215                 /* property not found */
 216                 if (ret == -EINVAL)
 217                         continue;
 218
 219                 /* use default value, when no value is specified */
 220                 if (ret)
 221                         val = par->default_value;
 222
 223                 pr_debug("found %s with value %u\n", par->property, val);
 224                 cfg[ncfg] = pinconf_to_config_packed(par->param, val);
 225                 ncfg++;
 226         }
 227
 228         ret = 0;
 229
 230         /* no configs found at all */
 231         if (ncfg == 0) {
 232                 *configs = NULL;
 233                 *nconfigs = 0;
 234                 goto out;
 235         }
 236
 237         /*
 238          * Now limit the number of configs to the real number of
 239          * found properties.
 240          */
 241         *configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
 242         if (!*configs) {
 243                 ret = -ENOMEM;
 244                 goto out;
 245         }
 246
 247         *nconfigs = ncfg;
 248
 249 out:
 250         kfree(cfg);
 251         return ret;
 252 }
 253
 254 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
 255                 struct device_node *np, struct pinctrl_map **map,
 256                 unsigned *reserved_maps, unsigned *num_maps,
 257                 enum pinctrl_map_type type)
 258 {
 259         int ret;
 260         const char *function;
 261         struct device *dev = pctldev->dev;
 262         unsigned long *configs = NULL;
 263         unsigned num_configs = 0;
 264         unsigned reserve;
 265         struct property *prop;
 266         const char *group;
 267
 268         ret = of_property_read_string(np, "function", &function);
 269         if (ret < 0) {
 270                 /* EINVAL=missing, which is fine since it's optional */
 271                 if (ret != -EINVAL)
 272                         dev_err(dev, "could not parse property function\n");
 273                 function = NULL;
 274         }
 275
 276         ret = pinconf_generic_parse_dt_config(np, &configs, &num_configs);
 277         if (ret < 0) {
 278                 dev_err(dev, "could not parse node property\n");
 279                 return ret;
 280         }
 281
 282         reserve = 0;
 283         if (function != NULL)
 284                 reserve++;
 285         if (num_configs)
 286                 reserve++;
 287         ret = of_property_count_strings(np, "pins");
 288         if (ret < 0) {
 289                 dev_err(dev, "could not parse property pins\n");
 290                 goto exit;
 291         }
 292         reserve *= ret;
 293
 294         ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
 295                         num_maps, reserve);
 296         if (ret < 0)
 297                 goto exit;
 298
 299         of_property_for_each_string(np, "pins", prop, group) {
 300                 if (function) {
 301                         ret = pinctrl_utils_add_map_mux(pctldev, map,
 302                                         reserved_maps, num_maps, group,
 303                                         function);
 304                         if (ret < 0)
 305                                 goto exit;
 306                 }
 307
 308                 if (num_configs) {
 309                         ret = pinctrl_utils_add_map_configs(pctldev, map,
 310                                         reserved_maps, num_maps, group, configs,
 311                                         num_configs, type);
 312                         if (ret < 0)
 313                                 goto exit;
 314                 }
 315         }
 316         ret = 0;
 317
 318 exit:
 319         kfree(configs);
 320         return ret;
 321 }
 322 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
 323
 324 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
 325                 struct device_node *np_config, struct pinctrl_map **map,
 326                 unsigned *num_maps, enum pinctrl_map_type type)
 327 {
 328         unsigned reserved_maps;
 329         struct device_node *np;
 330         int ret;
 331
 332         reserved_maps = 0;
 333         *map = NULL;
 334         *num_maps = 0;
 335
 336         for_each_child_of_node(np_config, np) {
 337                 ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
 338                                         &reserved_maps, num_maps, type);
 339                 if (ret < 0) {
 340                         pinctrl_utils_dt_free_map(pctldev, *map, *num_maps);
 341                         return ret;
 342                 }
 343         }
 344         return 0;
 345 }
 346 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
 347
 348 #endif