xref: /openbmc/u-boot/arch/sandbox/include/asm/gpio.h (revision 4e3349b6)
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  * See file CREDITS for list of people who contributed to this
7  * project.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation; either version 2 of
12  * the License, or (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
22  * MA 02111-1307 USA
23  */
24 
25 #ifndef __ASM_SANDBOX_GPIO_H
26 #define __ASM_SANDBOX_GPIO_H
27 
28 /*
29  * We use the generic interface, and add a back-channel.
30  *
31  * The back-channel functions are declared in this file. They should not be used
32  * except in test code.
33  *
34  * Test code can, for example, call sandbox_gpio_set_value() to set the value of
35  * a simulated GPIO. From then on, normal code in U-Boot will see this new
36  * value when it calls gpio_get_value().
37  *
38  * NOTE: DO NOT use the functions in this file except in test code!
39  */
40 #include <asm-generic/gpio.h>
41 
42 /**
43  * Return the simulated value of a GPIO (used only in sandbox test code)
44  *
45  * @param gp	GPIO number
46  * @return -1 on error, 0 if GPIO is low, >0 if high
47  */
48 int sandbox_gpio_get_value(unsigned gp);
49 
50 /**
51  * Set the simulated value of a GPIO (used only in sandbox test code)
52  *
53  * @param gp	GPIO number
54  * @param value	value to set (0 for low, non-zero for high)
55  * @return -1 on error, 0 if ok
56  */
57 int sandbox_gpio_set_value(unsigned gp, int value);
58 
59 /**
60  * Return the simulated direction of a GPIO (used only in sandbox test code)
61  *
62  * @param gp	GPIO number
63  * @return -1 on error, 0 if GPIO is input, >0 if output
64  */
65 int sandbox_gpio_get_direction(unsigned gp);
66 
67 /**
68  * Set the simulated direction of a GPIO (used only in sandbox test code)
69  *
70  * @param gp	GPIO number
71  * @param output 0 to set as input, 1 to set as output
72  * @return -1 on error, 0 if ok
73  */
74 int sandbox_gpio_set_direction(unsigned gp, int output);
75 
76 /* Display information about each GPIO */
77 void gpio_info(void);
78 
79 #define gpio_status()	gpio_info()
80 
81 #endif
82