1 /* SPDX-License-Identifier: GPL-2.0-only */
2
3 #ifndef __SRC_INCLUDE_GPIO_H__
4 #define __SRC_INCLUDE_GPIO_H__
5
6 #include <soc/gpio.h> /* IWYU pragma: export */
7
8 #ifndef __ASSEMBLER__ /* __ASSEMBLER__ also covers __ACPI__ case */
9
10 #include <types.h>
11
12 /* <soc/gpio.h> must typedef a gpio_t that fits in 32 bits. */
13 _Static_assert(sizeof(gpio_t) <= sizeof(u32), "gpio_t doesn't fit in lb_gpio");
14
15 /* The following functions must be implemented by SoC/board code. */
16 int gpio_get(gpio_t gpio);
17 int gpio_tx_get(gpio_t gpio);
18 void gpio_set(gpio_t gpio, int value);
19 void gpio_input_pulldown(gpio_t gpio);
20 void gpio_input_pullup(gpio_t gpio);
21 void gpio_input(gpio_t gpio);
22 void gpio_output(gpio_t gpio, int value);
23 uint32_t _gpio_base3_value(const gpio_t gpio[], int num_gpio, int binary_first);
24
25 /*
26 * This function may be implemented by SoC/board code to provide
27 * a mapping from a GPIO pin to controller by returning the ACPI
28 * path for the controller that owns this GPIO.
29 *
30 * If not implemented the default handler will return NULL.
31 */
32 const char *gpio_acpi_path(gpio_t gpio);
33
34 /*
35 * This function may be implemented by SoC/board code to provide
36 * a mapping from the internal representation of a GPIO to the 16bit
37 * value used in an ACPI GPIO pin table entry.
38 *
39 * If not implemented by the SOC the default handler will return 0
40 * because the underlying type of gpio_t is unknown.
41 */
42 uint16_t gpio_acpi_pin(gpio_t gpio);
43
44 /*
45 * Read the value presented by the set of GPIOs, when each pin is interpreted
46 * as a base-2 digit (LOW = 0, HIGH = 1).
47 *
48 * gpio[]: pin positions to read. gpio[0] is less significant than gpio[1].
49 * num_gpio: number of pins to read.
50 *
51 * There are also pulldown and pullup variants which default each gpio to
52 * be configured with an internal pulldown and pullup, respectively.
53 */
54 uint32_t gpio_base2_value(const gpio_t gpio[], int num_gpio);
55 uint32_t gpio_pulldown_base2_value(const gpio_t gpio[], int num_gpio);
56 uint32_t gpio_pullup_base2_value(const gpio_t gpio[], int num_gpio);
57
58 /*
59 * Read the value presented by the set of GPIOs, when each pin is interpreted
60 * as a base-3 digit (LOW = 0, HIGH = 1, Z/floating = 2).
61 * Example: X1 = Z, X2 = 1 -> gpio_base3_value({GPIO(X1), GPIO(X2)}) = 5
62 * BASE3() from <base3.h> can generate numbers to compare the result to.
63 *
64 * gpio[]: pin positions to read. gpio[0] is less significant than gpio[1].
65 * num_gpio: number of pins to read.
66 */
gpio_base3_value(const gpio_t gpio[],int num_gpio)67 static inline uint32_t gpio_base3_value(const gpio_t gpio[], int num_gpio)
68 {
69 return _gpio_base3_value(gpio, num_gpio, 0);
70 }
71
72 /*
73 * Read the value presented by the set of GPIOs, when each pin is interpreted
74 * as a base-3 digit (LOW = 0, HIGH = 1, Z/floating = 2) in a non-standard
75 * ternary number system where the first 2^n natural numbers are represented
76 * as they would be in a binary system (without any Z digits), and the following
77 * 3^n-2^n numbers use the remaining ternary representations in the normal
78 * ternary system order (skipping the values that were already used up).
79 * This is useful for boards which initially used a binary board ID and later
80 * decided to switch to tri-state after some revisions have already been built.
81 * Example: For num_gpio = 2 we get the following representation:
82 *
83 * Number X1 X0
84 * 0 0 0
85 * 1 0 1
86 * 2 1 0
87 * 3 1 1 // Start counting ternaries back at 0 after this
88 * 4 0 2 // Skipping 00 and 01 which are already used up
89 * 5 1 2 // Skipping 10 and 11 which are already used up
90 * 6 2 0
91 * 7 2 1
92 * 8 2 2
93 *
94 * gpio[]: pin positions to read. gpio[0] is less significant than gpio[1].
95 * num_gpio: number of pins to read.
96 */
gpio_binary_first_base3_value(const gpio_t gpio[],int num_gpio)97 static inline uint32_t gpio_binary_first_base3_value(const gpio_t gpio[],
98 int num_gpio)
99 {
100 return _gpio_base3_value(gpio, num_gpio, 1);
101 }
102
103 #endif /* !__ASSEMBLER__ */
104
105 #endif /* __SRC_INCLUDE_GPIO_H__ */
106