1 /*
2  *  (C) Copyright 2010,2011
3  *  NVIDIA Corporation <www.nvidia.com>
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 #include <common.h>
25 #include <asm/io.h>
26 #include <asm/arch/tegra2.h>
27 #include <asm/arch/gpio.h>
28 
29 /*
30  * Routine: gpio_config_uart
31  * Description: Force GPIO_PI3 low on Seaboard so UART4 works.
32  */
33 void gpio_config_uart(void)
34 {
35 	int gp = GPIO_PI3;
36 	struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
37 	struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)];
38 	u32 val;
39 
40 	/* Enable UART via GPIO_PI3 (port 8, bit 3) so serial console works */
41 	val = readl(&bank->gpio_config[GPIO_PORT(gp)]);
42 	val |= 1 << GPIO_BIT(gp);
43 	writel(val, &bank->gpio_config[GPIO_PORT(gp)]);
44 
45 	val = readl(&bank->gpio_out[GPIO_PORT(gp)]);
46 	val &= ~(1 << GPIO_BIT(gp));
47 	writel(val, &bank->gpio_out[GPIO_PORT(gp)]);
48 
49 	val = readl(&bank->gpio_dir_out[GPIO_PORT(gp)]);
50 	val |= 1 << GPIO_BIT(gp);
51 	writel(val, &bank->gpio_dir_out[GPIO_PORT(gp)]);
52 }
53