1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
/*
* This file is part of the coreboot 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; version 2 of the License.
*
* 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.
*/
#ifndef __SRC_INCLUDE_GPIO_H__
#define __SRC_INCLUDE_GPIO_H__
#include <soc/gpio.h>
#include <types.h>
/* <soc/gpio.h> must typedef a gpio_t that fits in 32 bits. */
_Static_assert(sizeof(gpio_t) <= sizeof(u32), "gpio_t doesn't fit in lb_gpio");
/* The following functions must be implemented by SoC/board code. */
int gpio_get(gpio_t gpio);
void gpio_set(gpio_t gpio, int value);
void gpio_input_pulldown(gpio_t gpio);
void gpio_input_pullup(gpio_t gpio);
void gpio_input(gpio_t gpio);
void gpio_output(gpio_t gpio, int value);
uint32_t _gpio_base3_value(const gpio_t gpio[], int num_gpio, int binary_first);
/*
* This function may be implemented by SoC/board code to provide
* a mapping from a GPIO pin to controller by returning the ACPI
* path for the controller that owns this GPIO.
*
* If not implemented the default handler will return NULL.
*/
const char *gpio_acpi_path(gpio_t gpio);
/*
* This function may be implemented by SoC/board code to provide
* a mapping from the internal representation of a GPIO to the 16bit
* value used in an ACPI GPIO pin table entry.
*
* If not implemented by the SOC the default handler will return 0
* because the underlying type of gpio_t is unknown.
*/
uint16_t gpio_acpi_pin(gpio_t gpio);
/*
* Read the value presented by the set of GPIOs, when each pin is interpreted
* as a base-2 digit (LOW = 0, HIGH = 1).
*
* gpio[]: pin positions to read. gpio[0] is less significant than gpio[1].
* num_gpio: number of pins to read.
*
* There are also pulldown and pullup variants which default each gpio to
* be configured with an internal pulldown and pullup, respectively.
*/
uint32_t gpio_base2_value(const gpio_t gpio[], int num_gpio);
uint32_t gpio_pulldown_base2_value(const gpio_t gpio[], int num_gpio);
uint32_t gpio_pullup_base2_value(const gpio_t gpio[], int num_gpio);
/*
* Read the value presented by the set of GPIOs, when each pin is interpreted
* as a base-3 digit (LOW = 0, HIGH = 1, Z/floating = 2).
* Example: X1 = Z, X2 = 1 -> gpio_base3_value({GPIO(X1), GPIO(X2)}) = 5
* BASE3() from <base3.h> can generate numbers to compare the result to.
*
* gpio[]: pin positions to read. gpio[0] is less significant than gpio[1].
* num_gpio: number of pins to read.
*/
static inline uint32_t gpio_base3_value(const gpio_t gpio[], int num_gpio)
{
return _gpio_base3_value(gpio, num_gpio, 0);
}
/*
* Read the value presented by the set of GPIOs, when each pin is interpreted
* as a base-3 digit (LOW = 0, HIGH = 1, Z/floating = 2) in a non-standard
* ternary number system where the first 2^n natural numbers are represented
* as they would be in a binary system (without any Z digits), and the following
* 3^n-2^n numbers use the remaining ternary representations in the normal
* ternary system order (skipping the values that were already used up).
* This is useful for boards which initially used a binary board ID and later
* decided to switch to tri-state after some revisions have already been built.
* Example: For num_gpio = 2 we get the following representation:
*
* Number X1 X0
* 0 0 0
* 1 0 1
* 2 1 0
* 3 1 1 // Start counting ternaries back at 0 after this
* 4 0 2 // Skipping 00 and 01 which are already used up
* 5 1 2 // Skipping 10 and 11 which are already used up
* 6 2 0
* 7 2 1
* 8 2 2
*
* gpio[]: pin positions to read. gpio[0] is less significant than gpio[1].
* num_gpio: number of pins to read.
*/
static inline uint32_t gpio_binary_first_base3_value(const gpio_t gpio[],
int num_gpio)
{
return _gpio_base3_value(gpio, num_gpio, 1);
}
#endif /* __SRC_INCLUDE_GPIO_H__ */
|
