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https://github.com/u-boot/u-boot.git
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83d290c56f
When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
627 lines
22 KiB
C
627 lines
22 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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* Copyright (c) 2011 The Chromium OS Authors.
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* Copyright (c) 2011, NVIDIA Corp. All rights reserved.
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*/
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#ifndef _ASM_GENERIC_GPIO_H_
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#define _ASM_GENERIC_GPIO_H_
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#include <dm/ofnode.h>
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struct ofnode_phandle_args;
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/*
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* Generic GPIO API for U-Boot
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*
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* --
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* NB: This is deprecated. Please use the driver model functions instead:
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*
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* - gpio_request_by_name()
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* - dm_gpio_get_value() etc.
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*
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* For now we need a dm_ prefix on some functions to avoid name collision.
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* --
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*
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* GPIOs are numbered from 0 to GPIO_COUNT-1 which value is defined
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* by the SOC/architecture.
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*
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* Each GPIO can be an input or output. If an input then its value can
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* be read as 0 or 1. If an output then its value can be set to 0 or 1.
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* If you try to write an input then the value is undefined. If you try
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* to read an output, barring something very unusual, you will get
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* back the value of the output that you previously set.
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*
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* In some cases the operation may fail, for example if the GPIO number
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* is out of range, or the GPIO is not available because its pin is
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* being used by another function. In that case, functions may return
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* an error value of -1.
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*/
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/**
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* @deprecated Please use driver model instead
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* Request a GPIO. This should be called before any of the other functions
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* are used on this GPIO.
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*
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* Note: With driver model, the label is allocated so there is no need for
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* the caller to preserve it.
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*
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* @param gpio GPIO number
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* @param label User label for this GPIO
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* @return 0 if ok, -1 on error
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*/
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int gpio_request(unsigned gpio, const char *label);
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/**
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* @deprecated Please use driver model instead
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* Stop using the GPIO. This function should not alter pin configuration.
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*
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* @param gpio GPIO number
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* @return 0 if ok, -1 on error
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*/
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int gpio_free(unsigned gpio);
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/**
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* @deprecated Please use driver model instead
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* Make a GPIO an input.
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*
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* @param gpio GPIO number
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* @return 0 if ok, -1 on error
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*/
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int gpio_direction_input(unsigned gpio);
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/**
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* @deprecated Please use driver model instead
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* Make a GPIO an output, and set its value.
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*
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* @param gpio GPIO number
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* @param value GPIO value (0 for low or 1 for high)
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* @return 0 if ok, -1 on error
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*/
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int gpio_direction_output(unsigned gpio, int value);
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/**
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* @deprecated Please use driver model instead
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* Get a GPIO's value. This will work whether the GPIO is an input
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* or an output.
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*
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* @param gpio GPIO number
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* @return 0 if low, 1 if high, -1 on error
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*/
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int gpio_get_value(unsigned gpio);
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/**
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* @deprecated Please use driver model instead
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* Set an output GPIO's value. The GPIO must already be an output or
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* this function may have no effect.
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*
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* @param gpio GPIO number
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* @param value GPIO value (0 for low or 1 for high)
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* @return 0 if ok, -1 on error
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*/
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int gpio_set_value(unsigned gpio, int value);
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/* State of a GPIO, as reported by get_function() */
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enum gpio_func_t {
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GPIOF_INPUT = 0,
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GPIOF_OUTPUT,
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GPIOF_UNUSED, /* Not claimed */
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GPIOF_UNKNOWN, /* Not known */
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GPIOF_FUNC, /* Not used as a GPIO */
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GPIOF_COUNT,
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};
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struct udevice;
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struct gpio_desc {
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struct udevice *dev; /* Device, NULL for invalid GPIO */
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unsigned long flags;
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#define GPIOD_REQUESTED (1 << 0) /* Requested/claimed */
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#define GPIOD_IS_OUT (1 << 1) /* GPIO is an output */
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#define GPIOD_IS_IN (1 << 2) /* GPIO is an input */
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#define GPIOD_ACTIVE_LOW (1 << 3) /* value has active low */
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#define GPIOD_IS_OUT_ACTIVE (1 << 4) /* set output active */
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uint offset; /* GPIO offset within the device */
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/*
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* We could consider adding the GPIO label in here. Possibly we could
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* use this structure for internal GPIO information.
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*/
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};
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/**
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* dm_gpio_is_valid() - Check if a GPIO is valid
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*
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* @desc: GPIO description containing device, offset and flags,
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* previously returned by gpio_request_by_name()
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* @return true if valid, false if not
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*/
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static inline bool dm_gpio_is_valid(const struct gpio_desc *desc)
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{
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return desc->dev != NULL;
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}
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/**
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* gpio_get_status() - get the current GPIO status as a string
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*
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* Obtain the current GPIO status as a string which can be presented to the
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* user. A typical string is:
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*
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* "b4: in: 1 [x] sdmmc_cd"
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*
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* which means this is GPIO bank b, offset 4, currently set to input, current
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* value 1, [x] means that it is requested and the owner is 'sdmmc_cd'
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*
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* TODO(sjg@chromium.org): This should use struct gpio_desc
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*
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* @dev: Device to check
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* @offset: Offset of device GPIO to check
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* @buf: Place to put string
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* @buffsize: Size of string including \0
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*/
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int gpio_get_status(struct udevice *dev, int offset, char *buf, int buffsize);
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/**
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* gpio_get_function() - get the current function for a GPIO pin
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*
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* Note this returns GPIOF_UNUSED if the GPIO is not requested.
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*
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* TODO(sjg@chromium.org): This should use struct gpio_desc
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*
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* @dev: Device to check
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* @offset: Offset of device GPIO to check
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* @namep: If non-NULL, this is set to the name given when the GPIO
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* was requested, or -1 if it has not been requested
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* @return -ENODATA if the driver returned an unknown function,
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* -ENODEV if the device is not active, -EINVAL if the offset is invalid.
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* GPIOF_UNUSED if the GPIO has not been requested. Otherwise returns the
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* function from enum gpio_func_t.
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*/
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int gpio_get_function(struct udevice *dev, int offset, const char **namep);
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/**
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* gpio_get_raw_function() - get the current raw function for a GPIO pin
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*
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* Note this does not return GPIOF_UNUSED - it will always return the GPIO
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* driver's view of a pin function, even if it is not correctly set up.
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*
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* TODO(sjg@chromium.org): This should use struct gpio_desc
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*
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* @dev: Device to check
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* @offset: Offset of device GPIO to check
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* @namep: If non-NULL, this is set to the name given when the GPIO
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* was requested, or -1 if it has not been requested
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* @return -ENODATA if the driver returned an unknown function,
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* -ENODEV if the device is not active, -EINVAL if the offset is invalid.
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* Otherwise returns the function from enum gpio_func_t.
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*/
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int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep);
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/**
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* gpio_requestf() - request a GPIO using a format string for the owner
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*
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* This is a helper function for gpio_request(). It allows you to provide
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* a printf()-format string for the GPIO owner. It calls gpio_request() with
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* the string that is created
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*/
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int gpio_requestf(unsigned gpio, const char *fmt, ...)
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__attribute__ ((format (__printf__, 2, 3)));
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struct fdtdec_phandle_args;
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/**
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* gpio_xlate_offs_flags() - implementation for common use of dm_gpio_ops.xlate
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*
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* This routine sets the offset field to args[0] and the flags field to
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* GPIOD_ACTIVE_LOW if the GPIO_ACTIVE_LOW flag is present in args[1].
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*/
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int gpio_xlate_offs_flags(struct udevice *dev, struct gpio_desc *desc,
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struct ofnode_phandle_args *args);
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/**
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* struct struct dm_gpio_ops - Driver model GPIO operations
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*
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* Refer to functions above for description. These function largely copy
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* the old API.
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*
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* This is trying to be close to Linux GPIO API. Once the U-Boot uses the
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* new DM GPIO API, this should be really easy to flip over to the Linux
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* GPIO API-alike interface.
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*
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* Also it would be useful to standardise additional functions like
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* pullup, slew rate and drive strength.
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*
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* gpio_request() and gpio_free() are optional - if NULL then they will
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* not be called.
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*
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* Note that @offset is the offset from the base GPIO of the device. So
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* offset 0 is the device's first GPIO and offset o-1 is the last GPIO,
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* where o is the number of GPIO lines controlled by the device. A device
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* is typically used to control a single bank of GPIOs. Within complex
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* SoCs there may be many banks and therefore many devices all referring
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* to the different IO addresses within the SoC.
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*
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* The uclass combines all GPIO devices together to provide a consistent
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* numbering from 0 to n-1, where n is the number of GPIOs in total across
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* all devices. Be careful not to confuse offset with gpio in the parameters.
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*/
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struct dm_gpio_ops {
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int (*request)(struct udevice *dev, unsigned offset, const char *label);
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int (*free)(struct udevice *dev, unsigned offset);
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int (*direction_input)(struct udevice *dev, unsigned offset);
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int (*direction_output)(struct udevice *dev, unsigned offset,
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int value);
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int (*get_value)(struct udevice *dev, unsigned offset);
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int (*set_value)(struct udevice *dev, unsigned offset, int value);
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int (*get_open_drain)(struct udevice *dev, unsigned offset);
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int (*set_open_drain)(struct udevice *dev, unsigned offset, int value);
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/**
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* get_function() Get the GPIO function
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*
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* @dev: Device to check
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* @offset: GPIO offset within that device
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* @return current function - GPIOF_...
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*/
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int (*get_function)(struct udevice *dev, unsigned offset);
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/**
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* xlate() - Translate phandle arguments into a GPIO description
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*
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* This function should set up the fields in desc according to the
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* information in the arguments. The uclass will have set up:
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*
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* @desc->dev to @dev
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* @desc->flags to 0
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* @desc->offset to 0
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*
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* This method is optional and defaults to gpio_xlate_offs_flags,
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* which will parse offset and the GPIO_ACTIVE_LOW flag in the first
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* two arguments.
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*
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* Note that @dev is passed in as a parameter to follow driver model
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* uclass conventions, even though it is already available as
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* desc->dev.
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*
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* @dev: GPIO device
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* @desc: Place to put GPIO description
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* @args: Arguments provided in description
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* @return 0 if OK, -ve on error
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*/
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int (*xlate)(struct udevice *dev, struct gpio_desc *desc,
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struct ofnode_phandle_args *args);
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};
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/**
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* struct gpio_dev_priv - information about a device used by the uclass
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*
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* The uclass combines all active GPIO devices into a unified numbering
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* scheme. To do this it maintains some private information about each
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* device.
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*
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* To implement driver model support in your GPIO driver, add a probe
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* handler, and set @gpio_count and @bank_name correctly in that handler.
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* This tells the uclass the name of the GPIO bank and the number of GPIOs
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* it contains.
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*
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* @bank_name: Name of the GPIO device (e.g 'a' means GPIOs will be called
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* 'A0', 'A1', etc.
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* @gpio_count: Number of GPIOs in this device
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* @gpio_base: Base GPIO number for this device. For the first active device
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* this will be 0; the numbering for others will follow sequentially so that
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* @gpio_base for device 1 will equal the number of GPIOs in device 0.
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* @name: Array of pointers to the name for each GPIO in this bank. The
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* value of the pointer will be NULL if the GPIO has not been claimed.
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*/
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struct gpio_dev_priv {
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const char *bank_name;
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unsigned gpio_count;
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unsigned gpio_base;
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char **name;
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};
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/* Access the GPIO operations for a device */
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#define gpio_get_ops(dev) ((struct dm_gpio_ops *)(dev)->driver->ops)
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/**
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* gpio_get_bank_info - Return information about a GPIO bank/device
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*
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* This looks up a device and returns both its GPIO base name and the number
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* of GPIOs it controls.
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*
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* @dev: Device to look up
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* @offset_count: Returns number of GPIOs within this bank
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* @return bank name of this device
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*/
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const char *gpio_get_bank_info(struct udevice *dev, int *offset_count);
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/**
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* dm_gpio_lookup_name() - Look up a named GPIO and return its description
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*
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* The name of a GPIO is typically its bank name followed by a number from 0.
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* For example A0 is the first GPIO in bank A. Each bank is a separate driver
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* model device.
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*
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* @name: Name to look up
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* @desc: Returns description, on success
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* @return 0 if OK, -ve on error
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*/
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int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc);
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/**
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* gpio_lookup_name - Look up a GPIO name and return its details
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*
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* This is used to convert a named GPIO into a device, offset and GPIO
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* number.
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*
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* @name: GPIO name to look up
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* @devp: Returns pointer to device which contains this GPIO
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* @offsetp: Returns the offset number within this device
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* @gpiop: Returns the absolute GPIO number, numbered from 0
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*/
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int gpio_lookup_name(const char *name, struct udevice **devp,
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unsigned int *offsetp, unsigned int *gpiop);
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/**
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* gpio_get_values_as_int() - Turn the values of a list of GPIOs into an int
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*
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* This puts the value of the first GPIO into bit 0, the second into bit 1,
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* etc. then returns the resulting integer.
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*
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* @gpio_list: List of GPIOs to collect
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* @return resulting integer value, or -ve on error
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*/
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int gpio_get_values_as_int(const int *gpio_list);
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/**
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* dm_gpio_get_values_as_int() - Turn the values of a list of GPIOs into an int
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*
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* This puts the value of the first GPIO into bit 0, the second into bit 1,
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* etc. then returns the resulting integer.
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*
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* @desc_list: List of GPIOs to collect
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* @count: Number of GPIOs
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* @return resulting integer value, or -ve on error
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*/
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int dm_gpio_get_values_as_int(const struct gpio_desc *desc_list, int count);
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/**
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* gpio_claim_vector() - claim a number of GPIOs for input
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*
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* @gpio_num_array: array of gpios to claim, terminated by -1
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* @fmt: format string for GPIO names, e.g. "board_id%d"
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* @return 0 if OK, -ve on error
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*/
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int gpio_claim_vector(const int *gpio_num_array, const char *fmt);
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/**
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* gpio_request_by_name() - Locate and request a GPIO by name
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*
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* This operates by looking up the given list name in the device (device
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* tree property) and requesting the GPIO for use. The property must exist
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* in @dev's node.
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*
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* Use @flags to specify whether the GPIO should be an input or output. In
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* principle this can also come from the device tree binding but most
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* bindings don't provide this information. Specifically, when the GPIO uclass
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* calls the xlate() method, it can return default flags, which are then
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* ORed with this @flags.
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*
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* If we find that requesting the GPIO is not always needed we could add a
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* new function or a new GPIOD_NO_REQUEST flag.
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*
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* At present driver model has no reference counting so if one device
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* requests a GPIO which subsequently is unbound, the @desc->dev pointer
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* will be invalid. However this will only happen if the GPIO device is
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* unbound, not if it is removed, so this seems like a reasonable limitation
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* for now. There is no real use case for unbinding drivers in normal
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* operation.
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*
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* The device tree binding is doc/device-tree-bindings/gpio/gpio.txt in
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* generate terms and each specific device may add additional details in
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* a binding file in the same directory.
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*
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* @dev: Device requesting the GPIO
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* @list_name: Name of GPIO list (e.g. "board-id-gpios")
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* @index: Index number of the GPIO in that list use request (0=first)
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* @desc: Returns GPIO description information. If there is no such
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* GPIO, dev->dev will be NULL.
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* @flags: Indicates the GPIO input/output settings (GPIOD_...)
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* @return 0 if OK, -ENOENT if the GPIO does not exist, -EINVAL if there is
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* something wrong with the list, or other -ve for another error (e.g.
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* -EBUSY if a GPIO was already requested)
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*/
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int gpio_request_by_name(struct udevice *dev, const char *list_name,
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int index, struct gpio_desc *desc, int flags);
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/**
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* gpio_request_list_by_name() - Request a list of GPIOs
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*
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* Reads all the GPIOs from a list and requests them. See
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* gpio_request_by_name() for additional details. Lists should not be
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* misused to hold unrelated or optional GPIOs. They should only be used
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* for things like parallel data lines. A zero phandle terminates the list
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* the list.
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*
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* This function will either succeed, and request all GPIOs in the list, or
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* fail and request none (it will free already-requested GPIOs in case of
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* an error part-way through).
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*
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* @dev: Device requesting the GPIO
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* @list_name: Name of GPIO list (e.g. "board-id-gpios")
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* @desc_list: Returns a list of GPIO description information
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* @max_count: Maximum number of GPIOs to return (@desc_list must be at least
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* this big)
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* @flags: Indicates the GPIO input/output settings (GPIOD_...)
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* @return number of GPIOs requested, or -ve on error
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*/
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int gpio_request_list_by_name(struct udevice *dev, const char *list_name,
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struct gpio_desc *desc_list, int max_count,
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int flags);
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/**
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* dm_gpio_request() - manually request a GPIO
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*
|
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* Note: This function should only be used for testing / debugging. Instead.
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* use gpio_request_by_name() to pull GPIOs from the device tree.
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*
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* @desc: GPIO description of GPIO to request (see dm_gpio_lookup_name())
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* @label: Label to attach to the GPIO while claimed
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* @return 0 if OK, -ve on error
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|
*/
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int dm_gpio_request(struct gpio_desc *desc, const char *label);
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|
|
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/**
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* gpio_get_list_count() - Returns the number of GPIOs in a list
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*
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* Counts the GPIOs in a list. See gpio_request_by_name() for additional
|
|
* details.
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*
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* @dev: Device requesting the GPIO
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* @list_name: Name of GPIO list (e.g. "board-id-gpios")
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* @return number of GPIOs (0 for an empty property) or -ENOENT if the list
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|
* does not exist
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|
*/
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|
int gpio_get_list_count(struct udevice *dev, const char *list_name);
|
|
|
|
/**
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* gpio_request_by_name_nodev() - request GPIOs without a device
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|
*
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* This is a version of gpio_request_list_by_name() that does not use a
|
|
* device. Avoid it unless the caller is not yet using driver model
|
|
*/
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int gpio_request_by_name_nodev(ofnode node, const char *list_name, int index,
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|
struct gpio_desc *desc, int flags);
|
|
|
|
/**
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|
* gpio_request_list_by_name_nodev() - request GPIOs without a device
|
|
*
|
|
* This is a version of gpio_request_list_by_name() that does not use a
|
|
* device. Avoid it unless the caller is not yet using driver model
|
|
*/
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|
int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
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struct gpio_desc *desc_list, int max_count,
|
|
int flags);
|
|
|
|
/**
|
|
* dm_gpio_free() - Free a single GPIO
|
|
*
|
|
* This frees a single GPIOs previously returned from gpio_request_by_name().
|
|
*
|
|
* @dev: Device which requested the GPIO
|
|
* @desc: GPIO to free
|
|
* @return 0 if OK, -ve on error
|
|
*/
|
|
int dm_gpio_free(struct udevice *dev, struct gpio_desc *desc);
|
|
|
|
/**
|
|
* gpio_free_list() - Free a list of GPIOs
|
|
*
|
|
* This frees a list of GPIOs previously returned from
|
|
* gpio_request_list_by_name().
|
|
*
|
|
* @dev: Device which requested the GPIOs
|
|
* @desc: List of GPIOs to free
|
|
* @count: Number of GPIOs in the list
|
|
* @return 0 if OK, -ve on error
|
|
*/
|
|
int gpio_free_list(struct udevice *dev, struct gpio_desc *desc, int count);
|
|
|
|
/**
|
|
* gpio_free_list_nodev() - free GPIOs without a device
|
|
*
|
|
* This is a version of gpio_free_list() that does not use a
|
|
* device. Avoid it unless the caller is not yet using driver model
|
|
*/
|
|
int gpio_free_list_nodev(struct gpio_desc *desc, int count);
|
|
|
|
/**
|
|
* dm_gpio_get_value() - Get the value of a GPIO
|
|
*
|
|
* This is the driver model version of the existing gpio_get_value() function
|
|
* and should be used instead of that.
|
|
*
|
|
* For now, these functions have a dm_ prefix since they conflict with
|
|
* existing names.
|
|
*
|
|
* @desc: GPIO description containing device, offset and flags,
|
|
* previously returned by gpio_request_by_name()
|
|
* @return GPIO value (0 for inactive, 1 for active) or -ve on error
|
|
*/
|
|
int dm_gpio_get_value(const struct gpio_desc *desc);
|
|
|
|
int dm_gpio_set_value(const struct gpio_desc *desc, int value);
|
|
|
|
/**
|
|
* dm_gpio_get_open_drain() - Check if open-drain-mode of a GPIO is active
|
|
*
|
|
* This checks if open-drain-mode for a GPIO is enabled or not. This method is
|
|
* optional.
|
|
*
|
|
* @desc: GPIO description containing device, offset and flags,
|
|
* previously returned by gpio_request_by_name()
|
|
* @return Value of open drain mode for GPIO (0 for inactive, 1 for active) or
|
|
* -ve on error
|
|
*/
|
|
int dm_gpio_get_open_drain(struct gpio_desc *desc);
|
|
|
|
/**
|
|
* dm_gpio_set_open_drain() - Switch open-drain-mode of a GPIO on or off
|
|
*
|
|
* This enables or disables open-drain mode for a GPIO. This method is
|
|
* optional; if the driver does not support it, nothing happens when the method
|
|
* is called.
|
|
*
|
|
* In open-drain mode, instead of actively driving the output (Push-pull
|
|
* output), the GPIO's pin is connected to the collector (for a NPN transistor)
|
|
* or the drain (for a MOSFET) of a transistor, respectively. The pin then
|
|
* either forms an open circuit or a connection to ground, depending on the
|
|
* state of the transistor.
|
|
*
|
|
* @desc: GPIO description containing device, offset and flags,
|
|
* previously returned by gpio_request_by_name()
|
|
* @return 0 if OK, -ve on error
|
|
*/
|
|
int dm_gpio_set_open_drain(struct gpio_desc *desc, int value);
|
|
|
|
/**
|
|
* dm_gpio_set_dir() - Set the direction for a GPIO
|
|
*
|
|
* This sets up the direction according tot the provided flags. It will do
|
|
* nothing unless the direction is actually specified.
|
|
*
|
|
* @desc: GPIO description containing device, offset and flags,
|
|
* previously returned by gpio_request_by_name()
|
|
* @return 0 if OK, -ve on error
|
|
*/
|
|
int dm_gpio_set_dir(struct gpio_desc *desc);
|
|
|
|
/**
|
|
* dm_gpio_set_dir_flags() - Set direction using specific flags
|
|
*
|
|
* This is like dm_gpio_set_dir() except that the flags value is provided
|
|
* instead of being used from desc->flags. This is needed because in many
|
|
* cases the GPIO description does not include direction information.
|
|
* Note that desc->flags is updated by this function.
|
|
*
|
|
* @desc: GPIO description containing device, offset and flags,
|
|
* previously returned by gpio_request_by_name()
|
|
* @flags: New flags to use
|
|
* @return 0 if OK, -ve on error, in which case desc->flags is not updated
|
|
*/
|
|
int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags);
|
|
|
|
/**
|
|
* gpio_get_number() - Get the global GPIO number of a GPIO
|
|
*
|
|
* This should only be used for debugging or interest. It returns the number
|
|
* that should be used for gpio_get_value() etc. to access this GPIO.
|
|
*
|
|
* @desc: GPIO description containing device, offset and flags,
|
|
* previously returned by gpio_request_by_name()
|
|
* @return GPIO number, or -ve if not found
|
|
*/
|
|
int gpio_get_number(const struct gpio_desc *desc);
|
|
|
|
#endif /* _ASM_GENERIC_GPIO_H_ */
|