xref: /openbmc/u-boot/arch/nios2/include/asm/gpio.h (revision ae03661f)
1 /*
2  * nios2 gpio driver
3  *
4  * This gpio core is described in http://nioswiki.com/GPIO
5  * bit[0] data
6  * bit[1] output enable
7  *
8  * When CONFIG_SYS_GPIO_BASE is not defined, the board may either
9  * provide its own driver or the altera_pio driver may be used.
10  *
11  * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License version 2 as
15  * published by the Free Software Foundation.
16  */
17 
18 #ifndef _ASM_NIOS2_GPIO_H_
19 #define _ASM_NIOS2_GPIO_H_
20 
21 #ifdef CONFIG_SYS_GPIO_BASE
22 #include <asm/io.h>
23 
24 static inline int gpio_request(unsigned gpio, const char *label)
25 {
26 	return 0;
27 }
28 
29 static inline int gpio_free(unsigned gpio)
30 {
31 	return 0;
32 }
33 
34 static inline int gpio_direction_input(unsigned gpio)
35 {
36 	writel(1, CONFIG_SYS_GPIO_BASE + (gpio << 2));
37 	return 0;
38 }
39 
40 static inline int gpio_direction_output(unsigned gpio, int value)
41 {
42 	writel(value ? 3 : 2, CONFIG_SYS_GPIO_BASE + (gpio << 2));
43 	return 0;
44 }
45 
46 static inline int gpio_get_value(unsigned gpio)
47 {
48 	return readl(CONFIG_SYS_GPIO_BASE + (gpio << 2));
49 }
50 
51 static inline void gpio_set_value(unsigned gpio, int value)
52 {
53 	writel(value ? 3 : 2, CONFIG_SYS_GPIO_BASE + (gpio << 2));
54 }
55 
56 static inline int gpio_is_valid(int number)
57 {
58 	return ((unsigned)number) < CONFIG_SYS_GPIO_WIDTH;
59 }
60 #else
61 #ifdef CONFIG_ALTERA_PIO
62 extern int altera_pio_init(u32 base, u8 width, char iot,
63 			   u32 rstval, u32 negmask,
64 			   const char *label);
65 
66 extern void altera_pio_info(void);
67 #define gpio_status() altera_pio_info()
68 #endif
69 
70 extern int gpio_request(unsigned gpio, const char *label);
71 extern int gpio_free(unsigned gpio);
72 extern int gpio_direction_input(unsigned gpio);
73 extern int gpio_direction_output(unsigned gpio, int value);
74 extern int gpio_get_value(unsigned gpio);
75 extern void gpio_set_value(unsigned gpio, int value);
76 extern int gpio_is_valid(int number);
77 #endif /* CONFIG_SYS_GPIO_BASE */
78 
79 #endif /* _ASM_NIOS2_GPIO_H_ */
80