1 /* arch/arm/plat-samsung/watchdog-reset.c
3 * Copyright (c) 2008 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
6 * Copyright (c) 2013 Tomasz Figa <tomasz.figa@gmail.com>
8 * Watchdog reset support for Samsung SoCs.
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
15 #include <linux/clk.h>
16 #include <linux/err.h>
18 #include <linux/delay.h>
20 #include <linux/of_address.h>
22 #define S3C2410_WTCON 0x00
23 #define S3C2410_WTDAT 0x04
24 #define S3C2410_WTCNT 0x08
26 #define S3C2410_WTCON_ENABLE (1 << 5)
27 #define S3C2410_WTCON_DIV16 (0 << 3)
28 #define S3C2410_WTCON_RSTEN (1 << 0)
29 #define S3C2410_WTCON_PRESCALE(x) ((x) << 8)
31 static void __iomem
*wdt_base
;
32 static struct clk
*wdt_clock
;
34 void samsung_wdt_reset(void)
37 pr_err("%s: wdt reset not initialized\n", __func__
);
38 /* delay to allow the serial port to show the message */
43 if (!IS_ERR(wdt_clock
))
44 clk_prepare_enable(wdt_clock
);
46 /* disable watchdog, to be safe */
47 __raw_writel(0, wdt_base
+ S3C2410_WTCON
);
49 /* put initial values into count and data */
50 __raw_writel(0x80, wdt_base
+ S3C2410_WTCNT
);
51 __raw_writel(0x80, wdt_base
+ S3C2410_WTDAT
);
53 /* set the watchdog to go and reset... */
54 __raw_writel(S3C2410_WTCON_ENABLE
| S3C2410_WTCON_DIV16
|
55 S3C2410_WTCON_RSTEN
| S3C2410_WTCON_PRESCALE(0x20),
56 wdt_base
+ S3C2410_WTCON
);
58 /* wait for reset to assert... */
61 pr_err("Watchdog reset failed to assert reset\n");
63 /* delay to allow the serial port to show the message */
68 static const struct of_device_id s3c2410_wdt_match
[] = {
69 { .compatible
= "samsung,s3c2410-wdt" },
73 void __init
samsung_wdt_reset_of_init(void)
75 struct device_node
*np
;
77 np
= of_find_matching_node(NULL
, s3c2410_wdt_match
);
79 pr_err("%s: failed to find watchdog node\n", __func__
);
83 wdt_base
= of_iomap(np
, 0);
85 pr_err("%s: failed to map watchdog registers\n", __func__
);
89 wdt_clock
= of_clk_get(np
, 0);
93 void __init
samsung_wdt_reset_init(void __iomem
*base
)
96 wdt_clock
= clk_get(NULL
, "watchdog");