mirror of
https://github.com/brain-hackers/u-boot-brain
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546 lines
19 KiB
C
546 lines
19 KiB
C
/*
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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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* SPDX-License-Identifier: GPL-2.0+
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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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/*
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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(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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* 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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/**
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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 the value of the first argument in args, if any,
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* otherwise -1 (which is invalid)
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*
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* This method is optional so if the above defaults suit it can be
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* omitted. Typical behaviour is to set up the GPIOD_ACTIVE_LOW flag
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* in desc->flags.
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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 fdtdec_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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* 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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* 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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* 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
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* 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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/**
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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
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* device. Avoid it unless the caller is not yet using driver model
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*/
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int gpio_request_by_name_nodev(const void *blob, int node,
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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_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
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* device. Avoid it unless the caller is not yet using driver model
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*/
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int gpio_request_list_by_name_nodev(const void *blob, int node,
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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_free() - Free a single GPIO
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*
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* This frees a single GPIOs previously returned from gpio_request_by_name().
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*
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* @dev: Device which requested the GPIO
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* @desc: GPIO to free
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* @return 0 if OK, -ve on error
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*/
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int dm_gpio_free(struct udevice *dev, struct gpio_desc *desc);
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/**
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* gpio_free_list() - Free a list of GPIOs
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*
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* This frees a list of GPIOs previously returned from
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* gpio_request_list_by_name().
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*
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* @dev: Device which requested the GPIOs
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* @desc: List of GPIOs to free
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* @count: Number of GPIOs in the list
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|
* @return 0 if OK, -ve on error
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|
*/
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|
int gpio_free_list(struct udevice *dev, struct gpio_desc *desc, int count);
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|
|
|
/**
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|
* gpio_free_list_nodev() - free GPIOs without a device
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|
*
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|
* 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
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|
*/
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|
int gpio_free_list_nodev(struct gpio_desc *desc, int count);
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|
|
|
/**
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|
* dm_gpio_get_value() - Get the value of a GPIO
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|
*
|
|
* This is the driver model version of the existing gpio_get_value() function
|
|
* and should be used instead of that.
|
|
*
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|
* For now, these functions have a dm_ prefix since they conflict with
|
|
* existing names.
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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 GPIO value (0 for inactive, 1 for active) or -ve on error
|
|
*/
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|
int dm_gpio_get_value(struct gpio_desc *desc);
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|
|
|
int dm_gpio_set_value(struct gpio_desc *desc, int value);
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|
|
|
/**
|
|
* 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);
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|
|
|
/**
|
|
* 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);
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|
|
|
/**
|
|
* 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(struct gpio_desc *desc);
|
|
|
|
#endif /* _ASM_GENERIC_GPIO_H_ */
|