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_BUS_HOLD, "input bias bus hold", NULL),
  42         PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL),
  43         PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL),
  44         PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
  45                                 "input bias pull to pin specific state", NULL),
  46         PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL),
  47         PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL),
  48         PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL),
  49         PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA"),
  50         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL),
  51         PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL),
  52         PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "time units"),
  53         PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector"),
  54         PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL),
  55         PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode"),
  56         PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level"),
  57 };
  58
  59 void pinconf_generic_dump_pin(struct pinctrl_dev *pctldev,
  60                               struct seq_file *s, unsigned pin)
  61 {
  62         const struct pinconf_ops *ops = pctldev->desc->confops;
  63         int i;
  64
  65         if (!ops->is_generic)
  66                 return;
  67
  68         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
  69                 unsigned long config;
  70                 int ret;
  71
  72                 /* We want to check out this parameter */
  73                 config = pinconf_to_config_packed(conf_items[i].param, 0);
  74                 ret = pin_config_get_for_pin(pctldev, pin, &config);
  75                 /* These are legal errors */
  76                 if (ret == -EINVAL || ret == -ENOTSUPP)
  77                         continue;
  78                 if (ret) {
  79                         seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
  80                         continue;
  81                 }
  82                 /* Space between multiple configs */
  83                 seq_puts(s, " ");
  84                 seq_puts(s, conf_items[i].display);
  85                 /* Print unit if available */
  86                 if (conf_items[i].format &&
  87                     pinconf_to_config_argument(config) != 0)
  88                         seq_printf(s, " (%u %s)",
  89                                    pinconf_to_config_argument(config),
  90                                    conf_items[i].format);
  91         }
  92 }
  93
  94 void pinconf_generic_dump_group(struct pinctrl_dev *pctldev,
  95                               struct seq_file *s, const char *gname)
  96 {
  97         const struct pinconf_ops *ops = pctldev->desc->confops;
  98         int i;
  99
 100         if (!ops->is_generic)
 101                 return;
 102
 103         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
 104                 unsigned long config;
 105                 int ret;
 106
 107                 /* We want to check out this parameter */
 108                 config = pinconf_to_config_packed(conf_items[i].param, 0);
 109                 ret = pin_config_group_get(dev_name(pctldev->dev), gname,
 110                                            &config);
 111                 /* These are legal errors */
 112                 if (ret == -EINVAL || ret == -ENOTSUPP)
 113                         continue;
 114                 if (ret) {
 115                         seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
 116                         continue;
 117                 }
 118                 /* Space between multiple configs */
 119                 seq_puts(s, " ");
 120                 seq_puts(s, conf_items[i].display);
 121                 /* Print unit if available */
 122                 if (conf_items[i].format && config != 0)
 123                         seq_printf(s, " (%u %s)",
 124                                    pinconf_to_config_argument(config),
 125                                    conf_items[i].format);
 126         }
 127 }
 128
 129 void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
 130                                  struct seq_file *s, unsigned long config)
 131 {
 132         int i;
 133
 134         for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
 135                 if (pinconf_to_config_param(config) != conf_items[i].param)
 136                         continue;
 137                 seq_printf(s, "%s: 0x%x", conf_items[i].display,
 138                            pinconf_to_config_argument(config));
 139         }
 140 }
 141 EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
 142 #endif
 143
 144 #ifdef CONFIG_OF
 145 struct pinconf_generic_dt_params {
 146         const char * const property;
 147         enum pin_config_param param;
 148         u32 default_value;
 149 };
 150
 151 static struct pinconf_generic_dt_params dt_params[] = {
 152         { "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
 153         { "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
 154         { "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
 155         { "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
 156         { "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
 157         { "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
 158         { "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
 159         { "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
 160         { "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
 161         { "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
 162         { "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
 163         { "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
 164         { "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
 165         { "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
 166         { "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
 167         { "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
 168         { "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
 169         { "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
 170         { "output-low", PIN_CONFIG_OUTPUT, 0, },
 171         { "output-high", PIN_CONFIG_OUTPUT, 1, },
 172 };
 173
 174 /**
 175  * pinconf_generic_parse_dt_config()
 176  * parse the config properties into generic pinconfig values.
 177  * @np: node containing the pinconfig properties
 178  * @configs: array with nconfigs entries containing the generic pinconf values
 179  * @nconfigs: umber of configurations
 180  */
 181 int pinconf_generic_parse_dt_config(struct device_node *np,
 182                                     unsigned long **configs,
 183                                     unsigned int *nconfigs)
 184 {
 185         unsigned long *cfg;
 186         unsigned int ncfg = 0;
 187         int ret;
 188         int i;
 189         u32 val;
 190
 191         if (!np)
 192                 return -EINVAL;
 193
 194         /* allocate a temporary array big enough to hold one of each option */
 195         cfg = kzalloc(sizeof(*cfg) * ARRAY_SIZE(dt_params), GFP_KERNEL);
 196         if (!cfg)
 197                 return -ENOMEM;
 198
 199         for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
 200                 struct pinconf_generic_dt_params *par = &dt_params[i];
 201                 ret = of_property_read_u32(np, par->property, &val);
 202
 203                 /* property not found */
 204                 if (ret == -EINVAL)
 205                         continue;
 206
 207                 /* use default value, when no value is specified */
 208                 if (ret)
 209                         val = par->default_value;
 210
 211                 pr_debug("found %s with value %u\n", par->property, val);
 212                 cfg[ncfg] = pinconf_to_config_packed(par->param, val);
 213                 ncfg++;
 214         }
 215
 216         ret = 0;
 217
 218         /* no configs found at all */
 219         if (ncfg == 0) {
 220                 *configs = NULL;
 221                 *nconfigs = 0;
 222                 goto out;
 223         }
 224
 225         /*
 226          * Now limit the number of configs to the real number of
 227          * found properties.
 228          */
 229         *configs = kzalloc(ncfg * sizeof(unsigned long), GFP_KERNEL);
 230         if (!*configs) {
 231                 ret = -ENOMEM;
 232                 goto out;
 233         }
 234
 235         memcpy(*configs, cfg, ncfg * sizeof(unsigned long));
 236         *nconfigs = ncfg;
 237
 238 out:
 239         kfree(cfg);
 240         return ret;
 241 }
 242 #endif