linux/drivers/pinctrl/pinconf-generic.c
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   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
  30struct 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
  38static 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", "usec"),
  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
  59void 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
  94void 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
 129void 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}
 141EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
 142#endif
 143
 144#ifdef CONFIG_OF
 145struct pinconf_generic_dt_params {
 146        const char * const property;
 147        enum pin_config_param param;
 148        u32 default_value;
 149};
 150
 151static 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-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 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 */
 178int 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
 235out:
 236        kfree(cfg);
 237        return ret;
 238}
 239#endif
 240
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