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e0e1e39de4
Some pin controllers (such as the Gemini) can control the expected clock skew and output delay on certain pins with a sub-nanosecond granularity. This is typically done by shunting in a number of double inverters in front of or behind the pin. Make it possible to configure this with a generic binding. Cc: devicetree@vger.kernel.org Acked-by: Rob Herring <robh@kernel.org> Acked-by: Hans Ulli Kroll <ulli.kroll@googlemail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
413 lines
12 KiB
C
413 lines
12 KiB
C
/*
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* Core driver for the generic pin config portions of the pin control subsystem
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*
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* Copyright (C) 2011 ST-Ericsson SA
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* Written on behalf of Linaro for ST-Ericsson
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*
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* Author: Linus Walleij <linus.walleij@linaro.org>
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*
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* License terms: GNU General Public License (GPL) version 2
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*/
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#define pr_fmt(fmt) "generic pinconfig core: " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/slab.h>
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#include <linux/debugfs.h>
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#include <linux/seq_file.h>
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#include <linux/pinctrl/pinctrl.h>
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#include <linux/pinctrl/pinconf.h>
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#include <linux/pinctrl/pinconf-generic.h>
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#include <linux/of.h>
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#include "core.h"
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#include "pinconf.h"
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#include "pinctrl-utils.h"
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#ifdef CONFIG_DEBUG_FS
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static const struct pin_config_item conf_items[] = {
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PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL, false),
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PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL, false),
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PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL, false),
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PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL, false),
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PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
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"input bias pull to pin specific state", NULL, false),
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PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL, false),
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PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL, false),
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PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),
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PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),
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PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA", true),
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PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec", true),
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PCONFDUMP(PIN_CONFIG_INPUT_ENABLE, "input enabled", NULL, false),
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PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL, false),
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PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL, false),
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PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode", true),
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PCONFDUMP(PIN_CONFIG_OUTPUT_ENABLE, "output enabled", NULL, false),
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PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level", true),
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PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true),
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PCONFDUMP(PIN_CONFIG_SLEEP_HARDWARE_STATE, "sleep hardware state", NULL, false),
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PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL, true),
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PCONFDUMP(PIN_CONFIG_SKEW_DELAY, "skew delay", NULL, true),
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};
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static void pinconf_generic_dump_one(struct pinctrl_dev *pctldev,
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struct seq_file *s, const char *gname,
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unsigned pin,
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const struct pin_config_item *items,
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int nitems, int *print_sep)
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{
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int i;
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for (i = 0; i < nitems; i++) {
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unsigned long config;
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int ret;
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/* We want to check out this parameter */
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config = pinconf_to_config_packed(items[i].param, 0);
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if (gname)
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ret = pin_config_group_get(dev_name(pctldev->dev),
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gname, &config);
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else
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ret = pin_config_get_for_pin(pctldev, pin, &config);
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/* These are legal errors */
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if (ret == -EINVAL || ret == -ENOTSUPP)
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continue;
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if (ret) {
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seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
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continue;
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}
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/* comma between multiple configs */
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if (*print_sep)
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seq_puts(s, ", ");
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*print_sep = 1;
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seq_puts(s, items[i].display);
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/* Print unit if available */
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if (items[i].has_arg) {
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seq_printf(s, " (%u",
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pinconf_to_config_argument(config));
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if (items[i].format)
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seq_printf(s, " %s)", items[i].format);
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else
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seq_puts(s, ")");
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}
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}
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}
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/**
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* pinconf_generic_dump_pins - Print information about pin or group of pins
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* @pctldev: Pincontrol device
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* @s: File to print to
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* @gname: Group name specifying pins
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* @pin: Pin number specyfying pin
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*
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* Print the pinconf configuration for the requested pin(s) to @s. Pins can be
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* specified either by pin using @pin or by group using @gname. Only one needs
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* to be specified the other can be NULL/0.
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*/
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void pinconf_generic_dump_pins(struct pinctrl_dev *pctldev, struct seq_file *s,
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const char *gname, unsigned pin)
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{
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const struct pinconf_ops *ops = pctldev->desc->confops;
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int print_sep = 0;
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if (!ops->is_generic)
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return;
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/* generic parameters */
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pinconf_generic_dump_one(pctldev, s, gname, pin, conf_items,
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ARRAY_SIZE(conf_items), &print_sep);
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/* driver-specific parameters */
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if (pctldev->desc->num_custom_params &&
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pctldev->desc->custom_conf_items)
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pinconf_generic_dump_one(pctldev, s, gname, pin,
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pctldev->desc->custom_conf_items,
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pctldev->desc->num_custom_params,
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&print_sep);
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}
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void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
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struct seq_file *s, unsigned long config)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
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if (pinconf_to_config_param(config) != conf_items[i].param)
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continue;
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seq_printf(s, "%s: 0x%x", conf_items[i].display,
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pinconf_to_config_argument(config));
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}
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if (!pctldev->desc->num_custom_params ||
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!pctldev->desc->custom_conf_items)
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return;
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for (i = 0; i < pctldev->desc->num_custom_params; i++) {
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if (pinconf_to_config_param(config) !=
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pctldev->desc->custom_conf_items[i].param)
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continue;
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seq_printf(s, "%s: 0x%x",
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pctldev->desc->custom_conf_items[i].display,
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pinconf_to_config_argument(config));
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}
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}
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EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
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#endif
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#ifdef CONFIG_OF
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static const struct pinconf_generic_params dt_params[] = {
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{ "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
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{ "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
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{ "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
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{ "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
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{ "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
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{ "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
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{ "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
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{ "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
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{ "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
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{ "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
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{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
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{ "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
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{ "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
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{ "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
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{ "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
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{ "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
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{ "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
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{ "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
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{ "output-disable", PIN_CONFIG_OUTPUT_ENABLE, 0 },
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{ "output-enable", PIN_CONFIG_OUTPUT_ENABLE, 1 },
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{ "output-high", PIN_CONFIG_OUTPUT, 1, },
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{ "output-low", PIN_CONFIG_OUTPUT, 0, },
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{ "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
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{ "sleep-hardware-state", PIN_CONFIG_SLEEP_HARDWARE_STATE, 0 },
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{ "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
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{ "skew-delay", PIN_CONFIG_SKEW_DELAY, 0 },
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};
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/**
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* parse_dt_cfg() - Parse DT pinconf parameters
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* @np: DT node
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* @params: Array of describing generic parameters
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* @count: Number of entries in @params
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* @cfg: Array of parsed config options
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* @ncfg: Number of entries in @cfg
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*
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* Parse the config options described in @params from @np and puts the result
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* in @cfg. @cfg does not need to be empty, entries are added beginning at
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* @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
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* needs to have enough memory allocated to hold all possible entries.
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*/
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static void parse_dt_cfg(struct device_node *np,
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const struct pinconf_generic_params *params,
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unsigned int count, unsigned long *cfg,
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unsigned int *ncfg)
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{
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int i;
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for (i = 0; i < count; i++) {
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u32 val;
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int ret;
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const struct pinconf_generic_params *par = ¶ms[i];
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ret = of_property_read_u32(np, par->property, &val);
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/* property not found */
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if (ret == -EINVAL)
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continue;
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/* use default value, when no value is specified */
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if (ret)
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val = par->default_value;
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pr_debug("found %s with value %u\n", par->property, val);
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cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
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(*ncfg)++;
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}
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}
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/**
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* pinconf_generic_parse_dt_config()
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* parse the config properties into generic pinconfig values.
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* @np: node containing the pinconfig properties
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* @configs: array with nconfigs entries containing the generic pinconf values
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* must be freed when no longer necessary.
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* @nconfigs: umber of configurations
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*/
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int pinconf_generic_parse_dt_config(struct device_node *np,
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struct pinctrl_dev *pctldev,
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unsigned long **configs,
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unsigned int *nconfigs)
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{
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unsigned long *cfg;
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unsigned int max_cfg, ncfg = 0;
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int ret;
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if (!np)
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return -EINVAL;
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/* allocate a temporary array big enough to hold one of each option */
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max_cfg = ARRAY_SIZE(dt_params);
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if (pctldev)
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max_cfg += pctldev->desc->num_custom_params;
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cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
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if (!cfg)
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return -ENOMEM;
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parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
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if (pctldev && pctldev->desc->num_custom_params &&
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pctldev->desc->custom_params)
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parse_dt_cfg(np, pctldev->desc->custom_params,
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pctldev->desc->num_custom_params, cfg, &ncfg);
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ret = 0;
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/* no configs found at all */
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if (ncfg == 0) {
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*configs = NULL;
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*nconfigs = 0;
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goto out;
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}
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/*
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* Now limit the number of configs to the real number of
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* found properties.
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*/
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*configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
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if (!*configs) {
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ret = -ENOMEM;
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goto out;
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}
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*nconfigs = ncfg;
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out:
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kfree(cfg);
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return ret;
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}
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int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
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struct device_node *np, struct pinctrl_map **map,
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unsigned *reserved_maps, unsigned *num_maps,
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enum pinctrl_map_type type)
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{
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int ret;
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const char *function;
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struct device *dev = pctldev->dev;
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unsigned long *configs = NULL;
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unsigned num_configs = 0;
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unsigned reserve, strings_count;
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struct property *prop;
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const char *group;
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const char *subnode_target_type = "pins";
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ret = of_property_count_strings(np, "pins");
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if (ret < 0) {
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ret = of_property_count_strings(np, "groups");
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if (ret < 0)
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/* skip this node; may contain config child nodes */
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return 0;
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if (type == PIN_MAP_TYPE_INVALID)
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type = PIN_MAP_TYPE_CONFIGS_GROUP;
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subnode_target_type = "groups";
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} else {
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if (type == PIN_MAP_TYPE_INVALID)
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type = PIN_MAP_TYPE_CONFIGS_PIN;
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}
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strings_count = ret;
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ret = of_property_read_string(np, "function", &function);
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if (ret < 0) {
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/* EINVAL=missing, which is fine since it's optional */
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if (ret != -EINVAL)
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dev_err(dev, "%pOF: could not parse property function\n",
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np);
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function = NULL;
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}
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ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
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&num_configs);
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if (ret < 0) {
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dev_err(dev, "%pOF: could not parse node property\n", np);
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return ret;
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}
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reserve = 0;
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if (function != NULL)
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reserve++;
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if (num_configs)
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reserve++;
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reserve *= strings_count;
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ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
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num_maps, reserve);
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if (ret < 0)
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goto exit;
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of_property_for_each_string(np, subnode_target_type, prop, group) {
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if (function) {
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ret = pinctrl_utils_add_map_mux(pctldev, map,
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reserved_maps, num_maps, group,
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function);
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if (ret < 0)
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goto exit;
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}
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if (num_configs) {
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ret = pinctrl_utils_add_map_configs(pctldev, map,
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reserved_maps, num_maps, group, configs,
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num_configs, type);
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if (ret < 0)
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goto exit;
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}
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}
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ret = 0;
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exit:
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kfree(configs);
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return ret;
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}
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EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
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int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
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struct device_node *np_config, struct pinctrl_map **map,
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unsigned *num_maps, enum pinctrl_map_type type)
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{
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unsigned reserved_maps;
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struct device_node *np;
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int ret;
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reserved_maps = 0;
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*map = NULL;
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*num_maps = 0;
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ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
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&reserved_maps, num_maps, type);
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if (ret < 0)
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goto exit;
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for_each_available_child_of_node(np_config, np) {
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ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
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&reserved_maps, num_maps, type);
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if (ret < 0)
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goto exit;
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}
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return 0;
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exit:
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pinctrl_utils_free_map(pctldev, *map, *num_maps);
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return ret;
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}
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EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
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void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
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struct pinctrl_map *map,
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unsigned num_maps)
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{
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pinctrl_utils_free_map(pctldev, map, num_maps);
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}
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EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
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#endif
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