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0d9a693cc8
With release of ACPI 5.1 and _DSD method we can finally name GPIOs (and
other things as well) returned by _CRS. Previously we were only able to
use integer index to find the corresponding GPIO, which is pretty error
prone if the order changes.
With _DSD we can now query GPIOs using name instead of an integer index,
like the below example shows:
// Bluetooth device with reset and shutdown GPIOs
Device (BTH)
{
Name (_HID, ...)
Name (_CRS, ResourceTemplate ()
{
GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly,
"\\_SB.GPO0", 0, ResourceConsumer) {15}
GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly,
"\\_SB.GPO0", 0, ResourceConsumer) {27, 31}
})
Name (_DSD, Package ()
{
ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
Package ()
{
Package () {"reset-gpio", Package() {^BTH, 1, 1, 0 }},
Package () {"shutdown-gpio", Package() {^BTH, 0, 0, 0 }},
}
})
}
The format of the supported GPIO property is:
Package () { "name", Package () { ref, index, pin, active_low }}
ref - The device that has _CRS containing GpioIo()/GpioInt() resources,
typically this is the device itself (BTH in our case).
index - Index of the GpioIo()/GpioInt() resource in _CRS starting from zero.
pin - Pin in the GpioIo()/GpioInt() resource. Typically this is zero.
active_low - If 1 the GPIO is marked as active_low.
Since ACPI GpioIo() resource does not have field saying whether it is
active low or high, the "active_low" argument can be used here. Setting
it to 1 marks the GPIO as active low.
In our Bluetooth example the "reset-gpio" refers to the second GpioIo()
resource, second pin in that resource with the GPIO number of 31.
This patch implements necessary support to gpiolib for extracting GPIOs
using _DSD device properties.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
155 lines
4.7 KiB
C
155 lines
4.7 KiB
C
/*
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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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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef GPIOLIB_H
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#define GPIOLIB_H
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#include <linux/err.h>
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#include <linux/device.h>
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enum of_gpio_flags;
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/**
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* struct acpi_gpio_info - ACPI GPIO specific information
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* @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
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* @active_low: in case of @gpioint, the pin is active low
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*/
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struct acpi_gpio_info {
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bool gpioint;
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bool active_low;
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};
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#ifdef CONFIG_ACPI
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void acpi_gpiochip_add(struct gpio_chip *chip);
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void acpi_gpiochip_remove(struct gpio_chip *chip);
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void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
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void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);
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struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
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const char *propname, int index,
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struct acpi_gpio_info *info);
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#else
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static inline void acpi_gpiochip_add(struct gpio_chip *chip) { }
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static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { }
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static inline void
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acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
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static inline void
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acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }
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static inline struct gpio_desc *
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acpi_get_gpiod_by_index(struct acpi_device *adev, const char *propname,
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int index, struct acpi_gpio_info *info)
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{
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return ERR_PTR(-ENOSYS);
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}
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#endif
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struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
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const char *list_name, int index, enum of_gpio_flags *flags);
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struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum);
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extern struct spinlock gpio_lock;
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extern struct list_head gpio_chips;
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struct gpio_desc {
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struct gpio_chip *chip;
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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_TRIG_FALL 4 /* trigger on falling edge */
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#define FLAG_TRIG_RISE 5 /* trigger on rising edge */
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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 ID_SHIFT 16 /* add new flags before this one */
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#define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1)
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#define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE))
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const char *label;
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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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/*
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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 int __maybe_unused gpio_chip_hwgpio(const struct gpio_desc *desc)
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{
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return desc - &desc->chip->desc[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(chip, fmt, ...) \
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pr_emerg("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
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#define chip_crit(chip, fmt, ...) \
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pr_crit("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
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#define chip_err(chip, fmt, ...) \
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pr_err("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
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#define chip_warn(chip, fmt, ...) \
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pr_warn("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
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#define chip_info(chip, fmt, ...) \
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pr_info("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
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#define chip_dbg(chip, fmt, ...) \
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pr_debug("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
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#ifdef CONFIG_GPIO_SYSFS
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int gpiochip_export(struct gpio_chip *chip);
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void gpiochip_unexport(struct gpio_chip *chip);
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#else
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static inline int gpiochip_export(struct gpio_chip *chip)
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{
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return 0;
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}
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static inline void gpiochip_unexport(struct gpio_chip *chip)
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{
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}
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#endif /* CONFIG_GPIO_SYSFS */
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#endif /* GPIOLIB_H */
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