xref: /openbmc/u-boot/drivers/gpio/spear_gpio.c (revision 4e3349b6)
1 /*
2  * Copyright (C) 2012 Stefan Roese <sr@denx.de>
3  *
4  * See file CREDITS for list of people who contributed to this
5  * project.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation; either version 2 of
10  * the License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
20  * MA 02111-1307 USA
21  */
22 
23 /*
24  * Driver for SPEAr600 GPIO controller
25  */
26 
27 #include <common.h>
28 #include <asm/arch/hardware.h>
29 #include <asm/gpio.h>
30 #include <asm/io.h>
31 #include <errno.h>
32 
33 static int gpio_direction(unsigned gpio,
34 			  enum gpio_direction direction)
35 {
36 	struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
37 	u32 val;
38 
39 	val = readl(&regs->gpiodir);
40 
41 	if (direction == GPIO_DIRECTION_OUT)
42 		val |= 1 << gpio;
43 	else
44 		val &= ~(1 << gpio);
45 
46 	writel(val, &regs->gpiodir);
47 
48 	return 0;
49 }
50 
51 int gpio_set_value(unsigned gpio, int value)
52 {
53 	struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
54 
55 	writel(1 << gpio, &regs->gpiodata[DATA_REG_ADDR(gpio)]);
56 
57 	return 0;
58 }
59 
60 int gpio_get_value(unsigned gpio)
61 {
62 	struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
63 	u32 val;
64 
65 	val = readl(&regs->gpiodata[DATA_REG_ADDR(gpio)]);
66 
67 	return !!val;
68 }
69 
70 int gpio_request(unsigned gpio, const char *label)
71 {
72 	if (gpio >= SPEAR_GPIO_COUNT)
73 		return -EINVAL;
74 
75 	return 0;
76 }
77 
78 int gpio_free(unsigned gpio)
79 {
80 	return 0;
81 }
82 
83 void gpio_toggle_value(unsigned gpio)
84 {
85 	gpio_set_value(gpio, !gpio_get_value(gpio));
86 }
87 
88 int gpio_direction_input(unsigned gpio)
89 {
90 	return gpio_direction(gpio, GPIO_DIRECTION_IN);
91 }
92 
93 int gpio_direction_output(unsigned gpio, int value)
94 {
95 	int ret = gpio_direction(gpio, GPIO_DIRECTION_OUT);
96 
97 	if (ret < 0)
98 		return ret;
99 
100 	gpio_set_value(gpio, value);
101 	return 0;
102 }
103