4c033b5499
Currently a GPIO lookup table can only refer to a specific GPIO by a tuple, consisting of a GPIO controller label and a GPIO offset inside the controller. However, a GPIO may also carry a line name, defined by DT or ACPI. If present, the line name is the most use-centric way to refer to a GPIO. Hence add support for looking up GPIOs by line name. Note that there is no guarantee that GPIO line names are globally unique, so this will use the first match found. Implement this by reusing the existing gpiod_lookup infrastructure. Rename gpiod_lookup.chip_label to gpiod_lookup.key, to make it clear that this field can have two meanings, and update the kerneldoc and GPIO_LOOKUP*() macros. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu> Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com> Link: https://lore.kernel.org/r/20200511145257.22970-4-geert+renesas@glider.be Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
114 lines
3.9 KiB
C
114 lines
3.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __LINUX_GPIO_MACHINE_H
|
|
#define __LINUX_GPIO_MACHINE_H
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/list.h>
|
|
|
|
enum gpio_lookup_flags {
|
|
GPIO_ACTIVE_HIGH = (0 << 0),
|
|
GPIO_ACTIVE_LOW = (1 << 0),
|
|
GPIO_OPEN_DRAIN = (1 << 1),
|
|
GPIO_OPEN_SOURCE = (1 << 2),
|
|
GPIO_PERSISTENT = (0 << 3),
|
|
GPIO_TRANSITORY = (1 << 3),
|
|
GPIO_PULL_UP = (1 << 4),
|
|
GPIO_PULL_DOWN = (1 << 5),
|
|
|
|
GPIO_LOOKUP_FLAGS_DEFAULT = GPIO_ACTIVE_HIGH | GPIO_PERSISTENT,
|
|
};
|
|
|
|
/**
|
|
* struct gpiod_lookup - lookup table
|
|
* @key: either the name of the chip the GPIO belongs to, or the GPIO line name
|
|
* Note that GPIO line names are not guaranteed to be globally unique,
|
|
* so this will use the first match found!
|
|
* @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO, or
|
|
* U16_MAX to indicate that @key is a GPIO line name
|
|
* @con_id: name of the GPIO from the device's point of view
|
|
* @idx: index of the GPIO in case several GPIOs share the same name
|
|
* @flags: bitmask of gpio_lookup_flags GPIO_* values
|
|
*
|
|
* gpiod_lookup is a lookup table for associating GPIOs to specific devices and
|
|
* functions using platform data.
|
|
*/
|
|
struct gpiod_lookup {
|
|
const char *key;
|
|
u16 chip_hwnum;
|
|
const char *con_id;
|
|
unsigned int idx;
|
|
unsigned long flags;
|
|
};
|
|
|
|
struct gpiod_lookup_table {
|
|
struct list_head list;
|
|
const char *dev_id;
|
|
struct gpiod_lookup table[];
|
|
};
|
|
|
|
/**
|
|
* struct gpiod_hog - GPIO line hog table
|
|
* @chip_label: name of the chip the GPIO belongs to
|
|
* @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO
|
|
* @line_name: consumer name for the hogged line
|
|
* @lflags: bitmask of gpio_lookup_flags GPIO_* values
|
|
* @dflags: GPIO flags used to specify the direction and value
|
|
*/
|
|
struct gpiod_hog {
|
|
struct list_head list;
|
|
const char *chip_label;
|
|
u16 chip_hwnum;
|
|
const char *line_name;
|
|
unsigned long lflags;
|
|
int dflags;
|
|
};
|
|
|
|
/*
|
|
* Simple definition of a single GPIO under a con_id
|
|
*/
|
|
#define GPIO_LOOKUP(_key, _chip_hwnum, _con_id, _flags) \
|
|
GPIO_LOOKUP_IDX(_key, _chip_hwnum, _con_id, 0, _flags)
|
|
|
|
/*
|
|
* Use this macro if you need to have several GPIOs under the same con_id.
|
|
* Each GPIO needs to use a different index and can be accessed using
|
|
* gpiod_get_index()
|
|
*/
|
|
#define GPIO_LOOKUP_IDX(_key, _chip_hwnum, _con_id, _idx, _flags) \
|
|
{ \
|
|
.key = _key, \
|
|
.chip_hwnum = _chip_hwnum, \
|
|
.con_id = _con_id, \
|
|
.idx = _idx, \
|
|
.flags = _flags, \
|
|
}
|
|
|
|
/*
|
|
* Simple definition of a single GPIO hog in an array.
|
|
*/
|
|
#define GPIO_HOG(_chip_label, _chip_hwnum, _line_name, _lflags, _dflags) \
|
|
{ \
|
|
.chip_label = _chip_label, \
|
|
.chip_hwnum = _chip_hwnum, \
|
|
.line_name = _line_name, \
|
|
.lflags = _lflags, \
|
|
.dflags = _dflags, \
|
|
}
|
|
|
|
#ifdef CONFIG_GPIOLIB
|
|
void gpiod_add_lookup_table(struct gpiod_lookup_table *table);
|
|
void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n);
|
|
void gpiod_remove_lookup_table(struct gpiod_lookup_table *table);
|
|
void gpiod_add_hogs(struct gpiod_hog *hogs);
|
|
#else /* ! CONFIG_GPIOLIB */
|
|
static inline
|
|
void gpiod_add_lookup_table(struct gpiod_lookup_table *table) {}
|
|
static inline
|
|
void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) {}
|
|
static inline
|
|
void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) {}
|
|
static inline void gpiod_add_hogs(struct gpiod_hog *hogs) {}
|
|
#endif /* CONFIG_GPIOLIB */
|
|
|
|
#endif /* __LINUX_GPIO_MACHINE_H */
|