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 };
  36
  37 #define PCONFDUMP(a, b, c) { .param = a, .display = b, .format = c }
  38
  39 static struct pin_config_item conf_items[] = {
  40         PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL),
  41         PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL),
  42         PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL),
  43         PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL),
  44         PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL),
  45         PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
  46                                 "input bias pull to pin specific state", NULL),
  47         PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL),
  48         PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL),
  49         PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL),
  50         PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA"),
  51         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL),
  52         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL),
  53         PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec"),
  54         PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector"),
  55         PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL),
  56         PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode"),
  57         PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level"),
  58 };
  59
  60 void pinconf_generic_dump_pin(struct pinctrl_dev *pctldev,
  61                               struct seq_file *s, unsigned pin)
  62 {
  63         const struct pinconf_ops *ops = pctldev->desc->confops;
  64         int i;
  65
  66         if (!ops->is_generic)
  67                 return;
  68
  69         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
  70                 unsigned long config;
  71                 int ret;
  72
  73                 /* We want to check out this parameter */
  74                 config = pinconf_to_config_packed(conf_items[i].param, 0);
  75                 ret = pin_config_get_for_pin(pctldev, pin, &config);
  76                 /* These are legal errors */
  77                 if (ret == -EINVAL || ret == -ENOTSUPP)
  78                         continue;
  79                 if (ret) {
  80                         seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
  81                         continue;
  82                 }
  83                 /* Space between multiple configs */
  84                 seq_puts(s, " ");
  85                 seq_puts(s, conf_items[i].display);
  86                 /* Print unit if available */
  87                 if (conf_items[i].format &&
  88                     pinconf_to_config_argument(config) != 0)
  89                         seq_printf(s, " (%u %s)",
  90                                    pinconf_to_config_argument(config),
  91                                    conf_items[i].format);
  92         }
  93 }
  94
  95 void pinconf_generic_dump_group(struct pinctrl_dev *pctldev,
  96                               struct seq_file *s, const char *gname)
  97 {
  98         const struct pinconf_ops *ops = pctldev->desc->confops;
  99         int i;
 100
 101         if (!ops->is_generic)
 102                 return;
 103
 104         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
 105                 unsigned long config;
 106                 int ret;
 107
 108                 /* We want to check out this parameter */
 109                 config = pinconf_to_config_packed(conf_items[i].param, 0);
 110                 ret = pin_config_group_get(dev_name(pctldev->dev), gname,
 111                                            &config);
 112                 /* These are legal errors */
 113                 if (ret == -EINVAL || ret == -ENOTSUPP)
 114                         continue;
 115                 if (ret) {
 116                         seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
 117                         continue;
 118                 }
 119                 /* Space between multiple configs */
 120                 seq_puts(s, " ");
 121                 seq_puts(s, conf_items[i].display);
 122                 /* Print unit if available */
 123                 if (conf_items[i].format && config != 0)
 124                         seq_printf(s, " (%u %s)",
 125                                    pinconf_to_config_argument(config),
 126                                    conf_items[i].format);
 127         }
 128 }
 129
 130 void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
 131                                  struct seq_file *s, unsigned long config)
 132 {
 133         int i;
 134
 135         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
 136                 if (pinconf_to_config_param(config) != conf_items[i].param)
 137                         continue;
 138                 seq_printf(s, "%s: 0x%x", conf_items[i].display,
 139                            pinconf_to_config_argument(config));
 140         }
 141 }
 142 EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
 143 #endif
 144
 145 #ifdef CONFIG_OF
 146 struct pinconf_generic_dt_params {
 147         const char * const property;
 148         enum pin_config_param param;
 149         u32 default_value;
 150 };
 151
 152 static struct pinconf_generic_dt_params dt_params[] = {
 153         { "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
 154         { "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
 155         { "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
 156         { "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
 157         { "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
 158         { "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
 159         { "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
 160         { "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
 161         { "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
 162         { "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
 163         { "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
 164         { "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
 165         { "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
 166         { "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
 167         { "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
 168         { "output-low", PIN_CONFIG_OUTPUT, 0, },
 169         { "output-high", PIN_CONFIG_OUTPUT, 1, },
 170 };
 171
 172 /**
 173  * pinconf_generic_parse_dt_config()
 174  * parse the config properties into generic pinconfig values.
 175  * @np: node containing the pinconfig properties
 176  * @configs: array with nconfigs entries containing the generic pinconf values
 177  * @nconfigs: umber of configurations
 178  */
 179 int pinconf_generic_parse_dt_config(struct device_node *np,
 180                                     unsigned long **configs,
 181                                     unsigned int *nconfigs)
 182 {
 183         unsigned long *cfg;
 184         unsigned int ncfg = 0;
 185         int ret;
 186         int i;
 187         u32 val;
 188
 189         if (!np)
 190                 return -EINVAL;
 191
 192         /* allocate a temporary array big enough to hold one of each option */
 193         cfg = kzalloc(sizeof(*cfg) * ARRAY_SIZE(dt_params), GFP_KERNEL);
 194         if (!cfg)
 195                 return -ENOMEM;
 196
 197         for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
 198                 struct pinconf_generic_dt_params *par = &dt_params[i];
 199                 ret = of_property_read_u32(np, par->property, &val);
 200
 201                 /* property not found */
 202                 if (ret == -EINVAL)
 203                         continue;
 204
 205                 /* use default value, when no value is specified */
 206                 if (ret)
 207                         val = par->default_value;
 208
 209                 pr_debug("found %s with value %u\n", par->property, val);
 210                 cfg[ncfg] = pinconf_to_config_packed(par->param, val);
 211                 ncfg++;
 212         }
 213
 214         ret = 0;
 215
 216         /* no configs found at all */
 217         if (ncfg == 0) {
 218                 *configs = NULL;
 219                 *nconfigs = 0;
 220                 goto out;
 221         }
 222
 223         /*
 224          * Now limit the number of configs to the real number of
 225          * found properties.
 226          */
 227         *configs = kzalloc(ncfg * sizeof(unsigned long), GFP_KERNEL);
 228         if (!*configs) {
 229                 ret = -ENOMEM;
 230                 goto out;
 231         }
 232
 233         memcpy(*configs, cfg, ncfg * sizeof(unsigned long));
 234         *nconfigs = ncfg;
 235
 236 out:
 237         kfree(cfg);
 238         return ret;
 239 }
 240
 241 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
 242                 struct device_node *np, struct pinctrl_map **map,
 243                 unsigned *reserved_maps, unsigned *num_maps,
 244                 enum pinctrl_map_type type)
 245 {
 246         int ret;
 247         const char *function;
 248         struct device *dev = pctldev->dev;
 249         unsigned long *configs = NULL;
 250         unsigned num_configs = 0;
 251         unsigned reserve;
 252         struct property *prop;
 253         const char *group;
 254
 255         ret = of_property_read_string(np, "function", &function);
 256         if (ret < 0) {
 257                 /* EINVAL=missing, which is fine since it's optional */
 258                 if (ret != -EINVAL)
 259                         dev_err(dev, "could not parse property function\n");
 260                 function = NULL;
 261         }
 262
 263         ret = pinconf_generic_parse_dt_config(np, &configs, &num_configs);
 264         if (ret < 0) {
 265                 dev_err(dev, "could not parse node property\n");
 266                 return ret;
 267         }
 268
 269         reserve = 0;
 270         if (function != NULL)
 271                 reserve++;
 272         if (num_configs)
 273                 reserve++;
 274         ret = of_property_count_strings(np, "pins");
 275         if (ret < 0) {
 276                 dev_err(dev, "could not parse property pins\n");
 277                 goto exit;
 278         }
 279         reserve *= ret;
 280
 281         ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
 282                         num_maps, reserve);
 283         if (ret < 0)
 284                 goto exit;
 285
 286         of_property_for_each_string(np, "pins", prop, group) {
 287                 if (function) {
 288                         ret = pinctrl_utils_add_map_mux(pctldev, map,
 289                                         reserved_maps, num_maps, group,
 290                                         function);
 291                         if (ret < 0)
 292                                 goto exit;
 293                 }
 294
 295                 if (num_configs) {
 296                         ret = pinctrl_utils_add_map_configs(pctldev, map,
 297                                         reserved_maps, num_maps, group, configs,
 298                                         num_configs, type);
 299                         if (ret < 0)
 300                                 goto exit;
 301                 }
 302         }
 303         ret = 0;
 304
 305 exit:
 306         kfree(configs);
 307         return ret;
 308 }
 309 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
 310
 311 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
 312                 struct device_node *np_config, struct pinctrl_map **map,
 313                 unsigned *num_maps, enum pinctrl_map_type type)
 314 {
 315         unsigned reserved_maps;
 316         struct device_node *np;
 317         int ret;
 318
 319         reserved_maps = 0;
 320         *map = NULL;
 321         *num_maps = 0;
 322
 323         for_each_child_of_node(np_config, np) {
 324                 ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
 325                                         &reserved_maps, num_maps, type);
 326                 if (ret < 0) {
 327                         pinctrl_utils_dt_free_map(pctldev, *map, *num_maps);
 328                         return ret;
 329                 }
 330         }
 331         return 0;
 332 }
 333 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
 334
 335 #endif