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_ENABLE, "input enabled", NULL),
  52         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL),
  53         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL),
  54         PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec"),
  55         PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector"),
  56         PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL),
  57         PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode"),
  58         PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level"),
  59 };
  60
  61 void pinconf_generic_dump_pin(struct pinctrl_dev *pctldev,
  62                               struct seq_file *s, unsigned pin)
  63 {
  64         const struct pinconf_ops *ops = pctldev->desc->confops;
  65         int i;
  66
  67         if (!ops->is_generic)
  68                 return;
  69
  70         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
  71                 unsigned long config;
  72                 int ret;
  73
  74                 /* We want to check out this parameter */
  75                 config = pinconf_to_config_packed(conf_items[i].param, 0);
  76                 ret = pin_config_get_for_pin(pctldev, pin, &config);
  77                 /* These are legal errors */
  78                 if (ret == -EINVAL || ret == -ENOTSUPP)
  79                         continue;
  80                 if (ret) {
  81                         seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
  82                         continue;
  83                 }
  84                 /* Space between multiple configs */
  85                 seq_puts(s, " ");
  86                 seq_puts(s, conf_items[i].display);
  87                 /* Print unit if available */
  88                 if (conf_items[i].format &&
  89                     pinconf_to_config_argument(config) != 0)
  90                         seq_printf(s, " (%u %s)",
  91                                    pinconf_to_config_argument(config),
  92                                    conf_items[i].format);
  93         }
  94 }
  95
  96 void pinconf_generic_dump_group(struct pinctrl_dev *pctldev,
  97                               struct seq_file *s, const char *gname)
  98 {
  99         const struct pinconf_ops *ops = pctldev->desc->confops;
 100         int i;
 101
 102         if (!ops->is_generic)
 103                 return;
 104
 105         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
 106                 unsigned long config;
 107                 int ret;
 108
 109                 /* We want to check out this parameter */
 110                 config = pinconf_to_config_packed(conf_items[i].param, 0);
 111                 ret = pin_config_group_get(dev_name(pctldev->dev), gname,
 112                                            &config);
 113                 /* These are legal errors */
 114                 if (ret == -EINVAL || ret == -ENOTSUPP)
 115                         continue;
 116                 if (ret) {
 117                         seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
 118                         continue;
 119                 }
 120                 /* Space between multiple configs */
 121                 seq_puts(s, " ");
 122                 seq_puts(s, conf_items[i].display);
 123                 /* Print unit if available */
 124                 if (conf_items[i].format && config != 0)
 125                         seq_printf(s, " (%u %s)",
 126                                    pinconf_to_config_argument(config),
 127                                    conf_items[i].format);
 128         }
 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 EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
 144 #endif
 145
 146 #ifdef CONFIG_OF
 147 struct pinconf_generic_dt_params {
 148         const char * const property;
 149         enum pin_config_param param;
 150         u32 default_value;
 151 };
 152
 153 static struct pinconf_generic_dt_params dt_params[] = {
 154         { "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
 155         { "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
 156         { "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
 157         { "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
 158         { "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
 159         { "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
 160         { "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
 161         { "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
 162         { "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
 163         { "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
 164         { "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
 165         { "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
 166         { "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
 167         { "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
 168         { "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
 169         { "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
 170         { "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
 171         { "output-low", PIN_CONFIG_OUTPUT, 0, },
 172         { "output-high", PIN_CONFIG_OUTPUT, 1, },
 173         { "slew-rate", PIN_CONFIG_SLEW_RATE, 0},
 174 };
 175
 176 /**
 177  * pinconf_generic_parse_dt_config()
 178  * parse the config properties into generic pinconfig values.
 179  * @np: node containing the pinconfig properties
 180  * @configs: array with nconfigs entries containing the generic pinconf values
 181  * @nconfigs: umber of configurations
 182  */
 183 int pinconf_generic_parse_dt_config(struct device_node *np,
 184                                     unsigned long **configs,
 185                                     unsigned int *nconfigs)
 186 {
 187         unsigned long *cfg;
 188         unsigned int ncfg = 0;
 189         int ret;
 190         int i;
 191         u32 val;
 192
 193         if (!np)
 194                 return -EINVAL;
 195
 196         /* allocate a temporary array big enough to hold one of each option */
 197         cfg = kzalloc(sizeof(*cfg) * ARRAY_SIZE(dt_params), GFP_KERNEL);
 198         if (!cfg)
 199                 return -ENOMEM;
 200
 201         for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
 202                 struct pinconf_generic_dt_params *par = &dt_params[i];
 203                 ret = of_property_read_u32(np, par->property, &val);
 204
 205                 /* property not found */
 206                 if (ret == -EINVAL)
 207                         continue;
 208
 209                 /* use default value, when no value is specified */
 210                 if (ret)
 211                         val = par->default_value;
 212
 213                 pr_debug("found %s with value %u\n", par->property, val);
 214                 cfg[ncfg] = pinconf_to_config_packed(par->param, val);
 215                 ncfg++;
 216         }
 217
 218         ret = 0;
 219
 220         /* no configs found at all */
 221         if (ncfg == 0) {
 222                 *configs = NULL;
 223                 *nconfigs = 0;
 224                 goto out;
 225         }
 226
 227         /*
 228          * Now limit the number of configs to the real number of
 229          * found properties.
 230          */
 231         *configs = kzalloc(ncfg * sizeof(unsigned long), GFP_KERNEL);
 232         if (!*configs) {
 233                 ret = -ENOMEM;
 234                 goto out;
 235         }
 236
 237         memcpy(*configs, cfg, ncfg * sizeof(unsigned long));
 238         *nconfigs = ncfg;
 239
 240 out:
 241         kfree(cfg);
 242         return ret;
 243 }
 244
 245 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
 246                 struct device_node *np, struct pinctrl_map **map,
 247                 unsigned *reserved_maps, unsigned *num_maps,
 248                 enum pinctrl_map_type type)
 249 {
 250         int ret;
 251         const char *function;
 252         struct device *dev = pctldev->dev;
 253         unsigned long *configs = NULL;
 254         unsigned num_configs = 0;
 255         unsigned reserve;
 256         struct property *prop;
 257         const char *group;
 258
 259         ret = of_property_read_string(np, "function", &function);
 260         if (ret < 0) {
 261                 /* EINVAL=missing, which is fine since it's optional */
 262                 if (ret != -EINVAL)
 263                         dev_err(dev, "could not parse property function\n");
 264                 function = NULL;
 265         }
 266
 267         ret = pinconf_generic_parse_dt_config(np, &configs, &num_configs);
 268         if (ret < 0) {
 269                 dev_err(dev, "could not parse node property\n");
 270                 return ret;
 271         }
 272
 273         reserve = 0;
 274         if (function != NULL)
 275                 reserve++;
 276         if (num_configs)
 277                 reserve++;
 278         ret = of_property_count_strings(np, "pins");
 279         if (ret < 0) {
 280                 dev_err(dev, "could not parse property pins\n");
 281                 goto exit;
 282         }
 283         reserve *= ret;
 284
 285         ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
 286                         num_maps, reserve);
 287         if (ret < 0)
 288                 goto exit;
 289
 290         of_property_for_each_string(np, "pins", prop, group) {
 291                 if (function) {
 292                         ret = pinctrl_utils_add_map_mux(pctldev, map,
 293                                         reserved_maps, num_maps, group,
 294                                         function);
 295                         if (ret < 0)
 296                                 goto exit;
 297                 }
 298
 299                 if (num_configs) {
 300                         ret = pinctrl_utils_add_map_configs(pctldev, map,
 301                                         reserved_maps, num_maps, group, configs,
 302                                         num_configs, type);
 303                         if (ret < 0)
 304                                 goto exit;
 305                 }
 306         }
 307         ret = 0;
 308
 309 exit:
 310         kfree(configs);
 311         return ret;
 312 }
 313 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
 314
 315 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
 316                 struct device_node *np_config, struct pinctrl_map **map,
 317                 unsigned *num_maps, enum pinctrl_map_type type)
 318 {
 319         unsigned reserved_maps;
 320         struct device_node *np;
 321         int ret;
 322
 323         reserved_maps = 0;
 324         *map = NULL;
 325         *num_maps = 0;
 326
 327         for_each_child_of_node(np_config, np) {
 328                 ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
 329                                         &reserved_maps, num_maps, type);
 330                 if (ret < 0) {
 331                         pinctrl_utils_dt_free_map(pctldev, *map, *num_maps);
 332                         return ret;
 333                 }
 334         }
 335         return 0;
 336 }
 337 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
 338
 339 #endif