xref: /openbmc/u-boot/arch/sandbox/include/asm/gpio.h (revision dd1033e4)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * This is the interface to the sandbox GPIO driver for test code which
4  * wants to change the GPIO values reported to U-Boot.
5  *
6  * Copyright (c) 2011 The Chromium OS Authors.
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 dev		device to use
30  * @param offset	GPIO offset within bank
31  * @return -1 on error, 0 if GPIO is low, >0 if high
32  */
33 int sandbox_gpio_get_value(struct udevice *dev, unsigned int offset);
34 
35 /**
36  * Set the simulated value of a GPIO (used only in sandbox test code)
37  *
38  * @param dev		device to use
39  * @param offset	GPIO offset within bank
40  * @param value		value to set (0 for low, non-zero for high)
41  * @return -1 on error, 0 if ok
42  */
43 int sandbox_gpio_set_value(struct udevice *dev, unsigned int offset, int value);
44 
45 /**
46  * Set or reset the simulated open drain mode of a GPIO (used only in sandbox
47  * test code)
48  *
49  * @param gp	GPIO number
50  * @param value	value to set (0 for enabled open drain mode, non-zero for
51  * 		disabled)
52  * @return -1 on error, 0 if ok
53  */
54 int sandbox_gpio_set_open_drain(struct udevice *dev, unsigned offset, int value);
55 
56 /**
57  * Return the state of the simulated open drain mode of a GPIO (used only in
58  * sandbox test code)
59  *
60  * @param gp	GPIO number
61  * @return -1 on error, 0 if GPIO is input, >0 if output
62  */
63 int sandbox_gpio_get_open_drain(struct udevice *dev, unsigned offset);
64 
65 /**
66  * Return the simulated direction of a GPIO (used only in sandbox test code)
67  *
68  * @param dev		device to use
69  * @param offset	GPIO offset within bank
70  * @return -1 on error, 0 if GPIO is input, >0 if output
71  */
72 int sandbox_gpio_get_direction(struct udevice *dev, unsigned int offset);
73 
74 /**
75  * Set the simulated direction of a GPIO (used only in sandbox test code)
76  *
77  * @param dev		device to use
78  * @param offset	GPIO offset within bank
79  * @param output 	0 to set as input, 1 to set as output
80  * @return -1 on error, 0 if ok
81  */
82 int sandbox_gpio_set_direction(struct udevice *dev, unsigned int offset,
83 			       int output);
84 
85 #endif
86