linux-stable/drivers/gpio/gpiolib.h
Thomas Petazzoni d449991c4d gpio: add core support for pull-up/pull-down configuration
This commit adds support for configuring the pull-up and pull-down
resistors available in some GPIO controllers. While configuring
pull-up/pull-down is already possible through the pinctrl subsystem,
some GPIO controllers, especially simple ones such as GPIO expanders
on I2C, don't have any pinmuxing capability and therefore do not use
the pinctrl subsystem.

This commit implements the GPIO_PULL_UP and GPIO_PULL_DOWN flags,
which can be used from the Device Tree, to enable a pull-up or
pull-down resistor on a given GPIO.

The flag is simply propagated all the way to the core GPIO subsystem,
where it is used to call the gpio_chip ->set_config callback with the
appropriate existing PIN_CONFIG_BIAS_* values.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-02-13 09:10:14 +01:00

303 lines
9.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Internal GPIO functions.
*
* Copyright (C) 2013, Intel Corporation
* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
*/
#ifndef GPIOLIB_H
#define GPIOLIB_H
#include <linux/gpio/driver.h>
#include <linux/gpio/consumer.h> /* for enum gpiod_flags */
#include <linux/err.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/cdev.h>
enum of_gpio_flags;
enum gpio_lookup_flags;
struct acpi_device;
/**
* struct gpio_device - internal state container for GPIO devices
* @id: numerical ID number for the GPIO chip
* @dev: the GPIO device struct
* @chrdev: character device for the GPIO device
* @mockdev: class device used by the deprecated sysfs interface (may be
* NULL)
* @owner: helps prevent removal of modules exporting active GPIOs
* @chip: pointer to the corresponding gpiochip, holding static
* data for this device
* @descs: array of ngpio descriptors.
* @ngpio: the number of GPIO lines on this GPIO device, equal to the size
* of the @descs array.
* @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
* at device creation time.
* @label: a descriptive name for the GPIO device, such as the part number
* or name of the IP component in a System on Chip.
* @data: per-instance data assigned by the driver
* @list: links gpio_device:s together for traversal
*
* This state container holds most of the runtime variable data
* for a GPIO device and can hold references and live on after the
* GPIO chip has been removed, if it is still being used from
* userspace.
*/
struct gpio_device {
int id;
struct device dev;
struct cdev chrdev;
struct device *mockdev;
struct module *owner;
struct gpio_chip *chip;
struct gpio_desc *descs;
int base;
u16 ngpio;
const char *label;
void *data;
struct list_head list;
#ifdef CONFIG_PINCTRL
/*
* If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
* describe the actual pin range which they serve in an SoC. This
* information would be used by pinctrl subsystem to configure
* corresponding pins for gpio usage.
*/
struct list_head pin_ranges;
#endif
};
/**
* struct acpi_gpio_info - ACPI GPIO specific information
* @adev: reference to ACPI device which consumes GPIO resource
* @flags: GPIO initialization flags
* @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
* @polarity: interrupt polarity as provided by ACPI
* @triggering: triggering type as provided by ACPI
* @quirks: Linux specific quirks as provided by struct acpi_gpio_mapping
*/
struct acpi_gpio_info {
struct acpi_device *adev;
enum gpiod_flags flags;
bool gpioint;
int polarity;
int triggering;
unsigned int quirks;
};
/* gpio suffixes used for ACPI and device tree lookup */
static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
#ifdef CONFIG_OF_GPIO
struct gpio_desc *of_find_gpio(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpio_lookup_flags *flags);
struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
const char *list_name, int index, enum of_gpio_flags *flags);
int of_gpiochip_add(struct gpio_chip *gc);
void of_gpiochip_remove(struct gpio_chip *gc);
#else
static inline struct gpio_desc *of_find_gpio(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpio_lookup_flags *flags)
{
return ERR_PTR(-ENOENT);
}
static inline struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
const char *list_name, int index, enum of_gpio_flags *flags)
{
return ERR_PTR(-ENOENT);
}
static inline int of_gpiochip_add(struct gpio_chip *gc) { return 0; }
static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
#endif /* CONFIG_OF_GPIO */
#ifdef CONFIG_ACPI
void acpi_gpiochip_add(struct gpio_chip *chip);
void acpi_gpiochip_remove(struct gpio_chip *chip);
void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);
int acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags,
struct acpi_gpio_info *info);
struct gpio_desc *acpi_find_gpio(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpiod_flags *dflags,
enum gpio_lookup_flags *lookupflags);
struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
const char *propname, int index,
struct acpi_gpio_info *info);
int acpi_gpio_count(struct device *dev, const char *con_id);
bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id);
#else
static inline void acpi_gpiochip_add(struct gpio_chip *chip) { }
static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { }
static inline void
acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
static inline void
acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }
static inline int
acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, struct acpi_gpio_info *info)
{
return 0;
}
static inline struct gpio_desc *
acpi_find_gpio(struct device *dev, const char *con_id,
unsigned int idx, enum gpiod_flags *dflags,
enum gpio_lookup_flags *lookupflags)
{
return ERR_PTR(-ENOENT);
}
static inline struct gpio_desc *
acpi_node_get_gpiod(struct fwnode_handle *fwnode, const char *propname,
int index, struct acpi_gpio_info *info)
{
return ERR_PTR(-ENXIO);
}
static inline int acpi_gpio_count(struct device *dev, const char *con_id)
{
return -ENODEV;
}
static inline bool acpi_can_fallback_to_crs(struct acpi_device *adev,
const char *con_id)
{
return false;
}
#endif
struct gpio_array {
struct gpio_desc **desc;
unsigned int size;
struct gpio_chip *chip;
unsigned long *get_mask;
unsigned long *set_mask;
unsigned long invert_mask[];
};
struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum);
int gpiod_get_array_value_complex(bool raw, bool can_sleep,
unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap);
int gpiod_set_array_value_complex(bool raw, bool can_sleep,
unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap);
extern struct spinlock gpio_lock;
extern struct list_head gpio_devices;
struct gpio_desc {
struct gpio_device *gdev;
unsigned long flags;
/* flag symbols are bit numbers */
#define FLAG_REQUESTED 0
#define FLAG_IS_OUT 1
#define FLAG_EXPORT 2 /* protected by sysfs_lock */
#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
#define FLAG_ACTIVE_LOW 6 /* value has active low */
#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
#define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
#define FLAG_IS_HOGGED 11 /* GPIO is hogged */
#define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
#define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
#define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
/* Connection label */
const char *label;
/* Name of the GPIO */
const char *name;
};
int gpiod_request(struct gpio_desc *desc, const char *label);
void gpiod_free(struct gpio_desc *desc);
int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
unsigned long lflags, enum gpiod_flags dflags);
int gpiod_hog(struct gpio_desc *desc, const char *name,
unsigned long lflags, enum gpiod_flags dflags);
/*
* Return the GPIO number of the passed descriptor relative to its chip
*/
static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
{
return desc - &desc->gdev->descs[0];
}
void devprop_gpiochip_set_names(struct gpio_chip *chip,
const struct fwnode_handle *fwnode);
/* With descriptor prefix */
#define gpiod_emerg(desc, fmt, ...) \
pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
##__VA_ARGS__)
#define gpiod_crit(desc, fmt, ...) \
pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
##__VA_ARGS__)
#define gpiod_err(desc, fmt, ...) \
pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
##__VA_ARGS__)
#define gpiod_warn(desc, fmt, ...) \
pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
##__VA_ARGS__)
#define gpiod_info(desc, fmt, ...) \
pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
##__VA_ARGS__)
#define gpiod_dbg(desc, fmt, ...) \
pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
##__VA_ARGS__)
/* With chip prefix */
#define chip_emerg(chip, fmt, ...) \
dev_emerg(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
#define chip_crit(chip, fmt, ...) \
dev_crit(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
#define chip_err(chip, fmt, ...) \
dev_err(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
#define chip_warn(chip, fmt, ...) \
dev_warn(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
#define chip_info(chip, fmt, ...) \
dev_info(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
#define chip_dbg(chip, fmt, ...) \
dev_dbg(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
#ifdef CONFIG_GPIO_SYSFS
int gpiochip_sysfs_register(struct gpio_device *gdev);
void gpiochip_sysfs_unregister(struct gpio_device *gdev);
#else
static inline int gpiochip_sysfs_register(struct gpio_device *gdev)
{
return 0;
}
static inline void gpiochip_sysfs_unregister(struct gpio_device *gdev)
{
}
#endif /* CONFIG_GPIO_SYSFS */
#endif /* GPIOLIB_H */