u-boot/arch/sandbox/include/asm/gpio.h
Simon Glass 8d30fcd9a1 sandbox: gpio: add basic driver for simulating GPIOs
This provides a way of simulating GPIOs by setting values which are seen
by the normal gpio_get/set_value() calls.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2012-03-12 11:03:42 -04:00

81 lines
2.5 KiB
C

/*
* This is the interface to the sandbox GPIO driver for test code which
* wants to change the GPIO values reported to U-Boot.
*
* Copyright (c) 2011 The Chromium OS Authors.
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#ifndef __ASM_SANDBOX_GPIO_H
#define __ASM_SANDBOX_GPIO_H
/*
* We use the generic interface, and add a back-channel.
*
* The back-channel functions are declared in this file. They should not be used
* except in test code.
*
* Test code can, for example, call sandbox_gpio_set_value() to set the value of
* a simulated GPIO. From then on, normal code in U-Boot will see this new
* value when it calls gpio_get_value().
*
* NOTE: DO NOT use the functions in this file except in test code!
*/
#include <asm-generic/gpio.h>
/**
* Return the simulated value of a GPIO (used only in sandbox test code)
*
* @param gp GPIO number
* @return -1 on error, 0 if GPIO is low, >0 if high
*/
int sandbox_gpio_get_value(unsigned gp);
/**
* Set the simulated value of a GPIO (used only in sandbox test code)
*
* @param gp GPIO number
* @param value value to set (0 for low, non-zero for high)
* @return -1 on error, 0 if ok
*/
int sandbox_gpio_set_value(unsigned gp, int value);
/**
* Return the simulated direction of a GPIO (used only in sandbox test code)
*
* @param gp GPIO number
* @return -1 on error, 0 if GPIO is input, >0 if output
*/
int sandbox_gpio_get_direction(unsigned gp);
/**
* Set the simulated direction of a GPIO (used only in sandbox test code)
*
* @param gp GPIO number
* @param output 0 to set as input, 1 to set as output
* @return -1 on error, 0 if ok
*/
int sandbox_gpio_set_direction(unsigned gp, int output);
/* Display information about each GPIO */
void gpio_info(void);
#define gpio_status() gpio_info()
#endif