f625d46017
Based on Boris Brezillion's work this is a reworked patch of his initial GPIO hogging mechanism. This patch provides a way to initially configure specific GPIO when the GPIO controller is probed. The actual DT scanning to collect the GPIO specific data is performed as part of gpiochip_add(). The purpose of this is to allow specific GPIOs to be configured without any driver specific code. This is particularly useful because board design are getting increasingly complex and given SoC pins can now have more than 10 mux values, a lot of connections are now dependent on external IO muxes to switch various modes. Specific drivers should not necessarily need to be aware of what accounts to a specific board implementation. This board level "description" should be best kept as part of the dts file. Signed-off-by: Benoit Parrot <bparrot@ti.com> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
158 lines
4.9 KiB
C
158 lines
4.9 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 FLAG_SYSFS_DIR 10 /* show sysfs direction attribute */
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#define FLAG_IS_HOGGED 11 /* GPIO is hogged */
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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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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 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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