xref: /openbmc/u-boot/drivers/watchdog/s5p_wdt.c (revision bf48fcb6)
1 /*
2  * Copyright (C) 2012 Samsung Electronics
3  * Minkyu Kang <mk7.kang@samsung.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/watchdog.h>
27 
28 #define PRESCALER_VAL 255
29 
30 void wdt_stop(void)
31 {
32 	struct s5p_watchdog *wdt =
33 		(struct s5p_watchdog *)samsung_get_base_watchdog();
34 	unsigned int wtcon;
35 
36 	wtcon = readl(&wdt->wtcon);
37 	wtcon &= ~(WTCON_EN | WTCON_INT | WTCON_RESET);
38 
39 	writel(wtcon, &wdt->wtcon);
40 }
41 
42 void wdt_start(unsigned int timeout)
43 {
44 	struct s5p_watchdog *wdt =
45 		(struct s5p_watchdog *)samsung_get_base_watchdog();
46 	unsigned int wtcon;
47 
48 	wdt_stop();
49 
50 	wtcon = readl(&wdt->wtcon);
51 	wtcon |= (WTCON_EN | WTCON_CLK(WTCON_CLK_128));
52 	wtcon &= ~WTCON_INT;
53 	wtcon |= WTCON_RESET;
54 	wtcon |= WTCON_PRESCALER(PRESCALER_VAL);
55 
56 	writel(timeout, &wdt->wtdat);
57 	writel(timeout, &wdt->wtcnt);
58 	writel(wtcon, &wdt->wtcon);
59 }
60