xref: /openbmc/u-boot/arch/sandbox/include/asm/gpio.h (revision ae51b570)
1 /*
2  * This is the interface to the sandbox GPIO driver for test code which
3  * wants to change the GPIO values reported to U-Boot.
4  *
5  * Copyright (c) 2011 The Chromium OS Authors.
6  * SPDX-License-Identifier:	GPL-2.0+
7  */
8 
9 #ifndef __ASM_SANDBOX_GPIO_H
10 #define __ASM_SANDBOX_GPIO_H
11 
12 /*
13  * We use the generic interface, and add a back-channel.
14  *
15  * The back-channel functions are declared in this file. They should not be used
16  * except in test code.
17  *
18  * Test code can, for example, call sandbox_gpio_set_value() to set the value of
19  * a simulated GPIO. From then on, normal code in U-Boot will see this new
20  * value when it calls gpio_get_value().
21  *
22  * NOTE: DO NOT use the functions in this file except in test code!
23  */
24 #include <asm-generic/gpio.h>
25 
26 /**
27  * Return the simulated value of a GPIO (used only in sandbox test code)
28  *
29  * @param gp	GPIO number
30  * @return -1 on error, 0 if GPIO is low, >0 if high
31  */
32 int sandbox_gpio_get_value(struct udevice *dev, unsigned int offset);
33 
34 /**
35  * Set the simulated value of a GPIO (used only in sandbox test code)
36  *
37  * @param gp	GPIO number
38  * @param value	value to set (0 for low, non-zero for high)
39  * @return -1 on error, 0 if ok
40  */
41 int sandbox_gpio_set_value(struct udevice *dev, unsigned int offset, int value);
42 
43 /**
44  * Return the simulated direction of a GPIO (used only in sandbox test code)
45  *
46  * @param gp	GPIO number
47  * @return -1 on error, 0 if GPIO is input, >0 if output
48  */
49 int sandbox_gpio_get_direction(struct udevice *dev, unsigned int offset);
50 
51 /**
52  * Set the simulated direction of a GPIO (used only in sandbox test code)
53  *
54  * @param gp	GPIO number
55  * @param output 0 to set as input, 1 to set as output
56  * @return -1 on error, 0 if ok
57  */
58 int sandbox_gpio_set_direction(struct udevice *dev, unsigned int offset,
59 			       int output);
60 
61 #endif
62