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
  28 #ifdef CONFIG_DEBUG_FS
  29
  30 struct pin_config_item {
  31         const enum pin_config_param param;
  32         const char * const display;
  33         const char * const format;
  34 };
  35
  36 #define PCONFDUMP(a, b, c) { .param = a, .display = b, .format = c }
  37
  38 static struct pin_config_item conf_items[] = {
  39         PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL),
  40         PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL),
  41         PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL),
  42         PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL),
  43         PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL),
  44         PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL),
  45         PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL),
  46         PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA"),
  47         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL),
  48         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL),
  49         PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "time units"),
  50         PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector"),
  51         PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL),
  52         PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode"),
  53         PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level"),
  54 };
  55
  56 void pinconf_generic_dump_pin(struct pinctrl_dev *pctldev,
  57                               struct seq_file *s, unsigned pin)
  58 {
  59         const struct pinconf_ops *ops = pctldev->desc->confops;
  60         int i;
  61
  62         if (!ops->is_generic)
  63                 return;
  64
  65         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
  66                 unsigned long config;
  67                 int ret;
  68
  69                 /* We want to check out this parameter */
  70                 config = pinconf_to_config_packed(conf_items[i].param, 0);
  71                 ret = pin_config_get_for_pin(pctldev, pin, &config);
  72                 /* These are legal errors */
  73                 if (ret == -EINVAL || ret == -ENOTSUPP)
  74                         continue;
  75                 if (ret) {
  76                         seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
  77                         continue;
  78                 }
  79                 /* Space between multiple configs */
  80                 seq_puts(s, " ");
  81                 seq_puts(s, conf_items[i].display);
  82                 /* Print unit if available */
  83                 if (conf_items[i].format &&
  84                     pinconf_to_config_argument(config) != 0)
  85                         seq_printf(s, " (%u %s)",
  86                                    pinconf_to_config_argument(config),
  87                                    conf_items[i].format);
  88         }
  89 }
  90
  91 void pinconf_generic_dump_group(struct pinctrl_dev *pctldev,
  92                               struct seq_file *s, const char *gname)
  93 {
  94         const struct pinconf_ops *ops = pctldev->desc->confops;
  95         int i;
  96
  97         if (!ops->is_generic)
  98                 return;
  99
 100         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
 101                 unsigned long config;
 102                 int ret;
 103
 104                 /* We want to check out this parameter */
 105                 config = pinconf_to_config_packed(conf_items[i].param, 0);
 106                 ret = pin_config_group_get(dev_name(pctldev->dev), gname,
 107                                            &config);
 108                 /* These are legal errors */
 109                 if (ret == -EINVAL || ret == -ENOTSUPP)
 110                         continue;
 111                 if (ret) {
 112                         seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
 113                         continue;
 114                 }
 115                 /* Space between multiple configs */
 116                 seq_puts(s, " ");
 117                 seq_puts(s, conf_items[i].display);
 118                 /* Print unit if available */
 119                 if (conf_items[i].format && config != 0)
 120                         seq_printf(s, " (%u %s)",
 121                                    pinconf_to_config_argument(config),
 122                                    conf_items[i].format);
 123         }
 124 }
 125
 126 void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
 127                                  struct seq_file *s, unsigned long config)
 128 {
 129         int i;
 130
 131         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
 132                 if (pinconf_to_config_param(config) != conf_items[i].param)
 133                         continue;
 134                 seq_printf(s, "%s: 0x%x", conf_items[i].display,
 135                            pinconf_to_config_argument(config));
 136         }
 137 }
 138 EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
 139 #endif
 140
 141 #ifdef CONFIG_OF
 142 struct pinconf_generic_dt_params {
 143         const char * const property;
 144         enum pin_config_param param;
 145         u32 default_value;
 146 };
 147
 148 static struct pinconf_generic_dt_params dt_params[] = {
 149         { "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
 150         { "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
 151         { "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
 152         { "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
 153         { "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
 154         { "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
 155         { "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
 156         { "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
 157         { "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
 158         { "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
 159         { "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
 160         { "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
 161         { "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
 162         { "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
 163         { "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
 164         { "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
 165         { "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
 166         { "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
 167         { "output-low", PIN_CONFIG_OUTPUT, 0, },
 168         { "output-high", PIN_CONFIG_OUTPUT, 1, },
 169 };
 170
 171 /**
 172  * pinconf_generic_parse_dt_config()
 173  * parse the config properties into generic pinconfig values.
 174  * @np: node containing the pinconfig properties
 175  * @configs: array with nconfigs entries containing the generic pinconf values
 176  * @nconfigs: umber of configurations
 177  */
 178 int pinconf_generic_parse_dt_config(struct device_node *np,
 179                                     unsigned long **configs,
 180                                     unsigned int *nconfigs)
 181 {
 182         unsigned long *cfg;
 183         unsigned int ncfg = 0;
 184         int ret;
 185         int i;
 186         u32 val;
 187
 188         if (!np)
 189                 return -EINVAL;
 190
 191         /* allocate a temporary array big enough to hold one of each option */
 192         cfg = kzalloc(sizeof(*cfg) * ARRAY_SIZE(dt_params), GFP_KERNEL);
 193         if (!cfg)
 194                 return -ENOMEM;
 195
 196         for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
 197                 struct pinconf_generic_dt_params *par = &dt_params[i];
 198                 ret = of_property_read_u32(np, par->property, &val);
 199
 200                 /* property not found */
 201                 if (ret == -EINVAL)
 202                         continue;
 203
 204                 /* use default value, when no value is specified */
 205                 if (ret)
 206                         val = par->default_value;
 207
 208                 pr_debug("found %s with value %u\n", par->property, val);
 209                 cfg[ncfg] = pinconf_to_config_packed(par->param, val);
 210                 ncfg++;
 211         }
 212
 213         ret = 0;
 214
 215         /* no configs found at all */
 216         if (ncfg == 0) {
 217                 *configs = NULL;
 218                 *nconfigs = 0;
 219                 goto out;
 220         }
 221
 222         /*
 223          * Now limit the number of configs to the real number of
 224          * found properties.
 225          */
 226         *configs = kzalloc(ncfg * sizeof(unsigned long), GFP_KERNEL);
 227         if (!*configs) {
 228                 ret = -ENOMEM;
 229                 goto out;
 230         }
 231
 232         memcpy(*configs, cfg, ncfg * sizeof(unsigned long));
 233         *nconfigs = ncfg;
 234
 235 out:
 236         kfree(cfg);
 237         return ret;
 238 }
 239 #endif