forked from luck/tmp_suning_uos_patched
65cff70464
Add support for setting debounce on a line via the GPIO uAPI. Where debounce is not supported by hardware, a software debounce is provided. The implementation of the software debouncer waits for the line to be stable for the debounce period before determining if a level change, and a corresponding edge event, has occurred. This provides maximum protection against glitches, but also introduces a debounce_period latency to edge events. The software debouncer is integrated with the edge detection as it utilises the line interrupt, and integration is simpler than getting the two to interwork. Where software debounce AND edge detection is required, the debouncer provides both. Signed-off-by: Kent Gibson <warthog618@gmail.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
185 lines
6.3 KiB
C
185 lines
6.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Internal GPIO functions.
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*
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* Copyright (C) 2013, Intel Corporation
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* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
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*/
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#ifndef GPIOLIB_H
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#define GPIOLIB_H
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#include <linux/gpio/driver.h>
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#include <linux/gpio/consumer.h> /* for enum gpiod_flags */
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#include <linux/err.h>
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/cdev.h>
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#define GPIOCHIP_NAME "gpiochip"
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/**
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* struct gpio_device - internal state container for GPIO devices
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* @id: numerical ID number for the GPIO chip
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* @dev: the GPIO device struct
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* @chrdev: character device for the GPIO device
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* @mockdev: class device used by the deprecated sysfs interface (may be
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* NULL)
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* @owner: helps prevent removal of modules exporting active GPIOs
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* @chip: pointer to the corresponding gpiochip, holding static
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* data for this device
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* @descs: array of ngpio descriptors.
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* @ngpio: the number of GPIO lines on this GPIO device, equal to the size
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* of the @descs array.
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* @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
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* at device creation time.
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* @label: a descriptive name for the GPIO device, such as the part number
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* or name of the IP component in a System on Chip.
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* @data: per-instance data assigned by the driver
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* @list: links gpio_device:s together for traversal
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*
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* This state container holds most of the runtime variable data
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* for a GPIO device and can hold references and live on after the
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* GPIO chip has been removed, if it is still being used from
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* userspace.
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*/
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struct gpio_device {
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int id;
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struct device dev;
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struct cdev chrdev;
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struct device *mockdev;
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struct module *owner;
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struct gpio_chip *chip;
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struct gpio_desc *descs;
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int base;
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u16 ngpio;
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const char *label;
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void *data;
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struct list_head list;
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struct blocking_notifier_head notifier;
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#ifdef CONFIG_PINCTRL
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/*
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* If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
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* describe the actual pin range which they serve in an SoC. This
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* information would be used by pinctrl subsystem to configure
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* corresponding pins for gpio usage.
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*/
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struct list_head pin_ranges;
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#endif
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};
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/* gpio suffixes used for ACPI and device tree lookup */
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static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
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struct gpio_array {
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struct gpio_desc **desc;
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unsigned int size;
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struct gpio_chip *chip;
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unsigned long *get_mask;
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unsigned long *set_mask;
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unsigned long invert_mask[];
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};
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struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
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int gpiod_get_array_value_complex(bool raw, bool can_sleep,
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unsigned int array_size,
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struct gpio_desc **desc_array,
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struct gpio_array *array_info,
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unsigned long *value_bitmap);
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int gpiod_set_array_value_complex(bool raw, bool can_sleep,
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unsigned int array_size,
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struct gpio_desc **desc_array,
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struct gpio_array *array_info,
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unsigned long *value_bitmap);
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extern spinlock_t gpio_lock;
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extern struct list_head gpio_devices;
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struct gpio_desc {
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struct gpio_device *gdev;
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unsigned long flags;
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/* flag symbols are bit numbers */
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#define FLAG_REQUESTED 0
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#define FLAG_IS_OUT 1
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#define FLAG_EXPORT 2 /* protected by sysfs_lock */
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#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
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#define FLAG_ACTIVE_LOW 6 /* value has active low */
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#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
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#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
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#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
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#define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
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#define FLAG_IS_HOGGED 11 /* GPIO is hogged */
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#define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
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#define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
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#define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
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#define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
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#define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
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#define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
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/* Connection label */
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const char *label;
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/* Name of the GPIO */
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const char *name;
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#ifdef CONFIG_OF_DYNAMIC
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struct device_node *hog;
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#endif
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#ifdef CONFIG_GPIO_CDEV
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/* debounce period in microseconds */
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unsigned int debounce_period_us;
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#endif
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};
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int gpiod_request(struct gpio_desc *desc, const char *label);
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void gpiod_free(struct gpio_desc *desc);
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int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
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unsigned long lflags, enum gpiod_flags dflags);
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int gpiod_hog(struct gpio_desc *desc, const char *name,
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unsigned long lflags, enum gpiod_flags dflags);
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/*
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* Return the GPIO number of the passed descriptor relative to its chip
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*/
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static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
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{
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return desc - &desc->gdev->descs[0];
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}
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/* With descriptor prefix */
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#define gpiod_emerg(desc, fmt, ...) \
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pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
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##__VA_ARGS__)
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#define gpiod_crit(desc, fmt, ...) \
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pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
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##__VA_ARGS__)
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#define gpiod_err(desc, fmt, ...) \
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pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
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##__VA_ARGS__)
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#define gpiod_warn(desc, fmt, ...) \
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pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
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##__VA_ARGS__)
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#define gpiod_info(desc, fmt, ...) \
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pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
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##__VA_ARGS__)
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#define gpiod_dbg(desc, fmt, ...) \
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pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
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##__VA_ARGS__)
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/* With chip prefix */
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#define chip_emerg(gc, fmt, ...) \
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dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
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#define chip_crit(gc, fmt, ...) \
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dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
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#define chip_err(gc, fmt, ...) \
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dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
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#define chip_warn(gc, fmt, ...) \
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dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
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#define chip_info(gc, fmt, ...) \
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dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
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#define chip_dbg(gc, fmt, ...) \
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dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
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#endif /* GPIOLIB_H */
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