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/*
* OF helpers for the GPIO API
*
* Copyright (c) 2007-2008 MontaVista Software, Inc.
*
* Author: Anton Vorontsov <avorontsov@ru.mvista.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/slab.h>
#include <linux/gpio/machine.h>
#include "gpiolib.h"
static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
{
struct of_phandle_args *gpiospec = data;
return chip->gpiodev->dev.of_node == gpiospec->np &&
chip->of_xlate(chip, gpiospec, NULL) >= 0;
}
static struct gpio_chip *of_find_gpiochip_by_xlate(
struct of_phandle_args *gpiospec)
{
return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
}
static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
struct of_phandle_args *gpiospec,
enum of_gpio_flags *flags)
{
int ret;
if (chip->of_gpio_n_cells != gpiospec->args_count)
return ERR_PTR(-EINVAL);
ret = chip->of_xlate(chip, gpiospec, flags);
if (ret < 0)
return ERR_PTR(ret);
return gpiochip_get_desc(chip, ret);
}
/**
* of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
* @np: device node to get GPIO from
* @propname: property name containing gpio specifier(s)
* @index: index of the GPIO
* @flags: a flags pointer to fill in
*
* Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
* value on the error condition. If @flags is not NULL the function also fills
* in flags for the GPIO.
*/
struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
const char *propname, int index, enum of_gpio_flags *flags)
{
struct of_phandle_args gpiospec;
struct gpio_chip *chip;
struct gpio_desc *desc;
int ret;
ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
&gpiospec);
if (ret) {
pr_debug("%s: can't parse '%s' property of node '%s[%d]'\n",
__func__, propname, np->full_name, index);
return ERR_PTR(ret);
}
chip = of_find_gpiochip_by_xlate(&gpiospec);
if (!chip) {
desc = ERR_PTR(-EPROBE_DEFER);
goto out;
}
desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
if (IS_ERR(desc))
goto out;
pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n",
__func__, propname, np->full_name, index,
PTR_ERR_OR_ZERO(desc));
out:
of_node_put(gpiospec.np);
return desc;
}
int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
int index, enum of_gpio_flags *flags)
{
struct gpio_desc *desc;
desc = of_get_named_gpiod_flags(np, list_name, index, flags);
if (IS_ERR(desc))
return PTR_ERR(desc);
else
return desc_to_gpio(desc);
}
EXPORT_SYMBOL(of_get_named_gpio_flags);
struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
unsigned int idx,
enum gpio_lookup_flags *flags)
{
char prop_name[32]; /* 32 is max size of property name */
enum of_gpio_flags of_flags;
struct gpio_desc *desc;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
if (con_id)
snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
gpio_suffixes[i]);
else
snprintf(prop_name, sizeof(prop_name), "%s",
gpio_suffixes[i]);
desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
&of_flags);
if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
break;
}
if (IS_ERR(desc))
return desc;
if (of_flags & OF_GPIO_ACTIVE_LOW)
*flags |= GPIO_ACTIVE_LOW;
if (of_flags & OF_GPIO_SINGLE_ENDED) {
if (of_flags & OF_GPIO_OPEN_DRAIN)
*flags |= GPIO_OPEN_DRAIN;
else
*flags |= GPIO_OPEN_SOURCE;
}
if (of_flags & OF_GPIO_SLEEP_MAY_LOOSE_VALUE)
*flags |= GPIO_SLEEP_MAY_LOOSE_VALUE;
return desc;
}
/**
* of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
* @np: device node to get GPIO from
* @chip: GPIO chip whose hog is parsed
* @idx: Index of the GPIO to parse
* @name: GPIO line name
* @lflags: gpio_lookup_flags - returned from of_find_gpio() or
* of_parse_own_gpio()
* @dflags: gpiod_flags - optional GPIO initialization flags
*
* Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
* value on the error condition.
*/
static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
struct gpio_chip *chip,
unsigned int idx, const char **name,
enum gpio_lookup_flags *lflags,
enum gpiod_flags *dflags)
{
struct device_node *chip_np;
enum of_gpio_flags xlate_flags;
struct of_phandle_args gpiospec;
struct gpio_desc *desc;
unsigned int i;
u32 tmp;
int ret;
chip_np = chip->of_node;
if (!chip_np)
return ERR_PTR(-EINVAL);
xlate_flags = 0;
*lflags = 0;
*dflags = 0;
ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
if (ret)
return ERR_PTR(ret);
gpiospec.np = chip_np;
gpiospec.args_count = tmp;
for (i = 0; i < tmp; i++) {
ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
&gpiospec.args[i]);
if (ret)
return ERR_PTR(ret);
}
desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
if (IS_ERR(desc))
return desc;
if (xlate_flags & OF_GPIO_ACTIVE_LOW)
*lflags |= GPIO_ACTIVE_LOW;
if (of_property_read_bool(np, "input"))
*dflags |= GPIOD_IN;
else if (of_property_read_bool(np, "output-low"))
*dflags |= GPIOD_OUT_LOW;
else if (of_property_read_bool(np, "output-high"))
*dflags |= GPIOD_OUT_HIGH;
else {
pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n",
desc_to_gpio(desc), np->name);
return ERR_PTR(-EINVAL);
}
if (name && of_property_read_string(np, "line-name", name))
*name = np->name;
return desc;
}
/**
* of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
* @chip: gpio chip to act on
*
* This is only used by of_gpiochip_add to request/set GPIO initial
* configuration.
* It returns error if it fails otherwise 0 on success.
*/
static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
{
struct gpio_desc *desc = NULL;
struct device_node *np;
const char *name;
enum gpio_lookup_flags lflags;
enum gpiod_flags dflags;
unsigned int i;
int ret;
for_each_available_child_of_node(chip->of_node, np) {
if (!of_property_read_bool
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