watchdog: Add watchdog support for W83627DHG chip

The following adds watchdog support for the Winbond W83627DHG chip.
I have tested it on a PQ7-M102XL (Intel Atom) board.

Signed-off-by: Benny Lønstrup Ammitzbøll <benny@ammitzboell-consult.dk>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/Kconfig

@@ -722,14 +722,15 @@ config SMSC37B787_WDT
 	  Most people will say N.
 
 config W83627HF_WDT
-	tristate "W83627HF Watchdog Timer"
+	tristate "W83627HF/W83627DHG Watchdog Timer"
 	depends on X86
 	---help---
 	  This is the driver for the hardware watchdog on the W83627HF chipset
 	  as used in Advantech PC-9578 and Tyan S2721-533 motherboards
-	  (and likely others).  This watchdog simply watches your kernel to
-	  make sure it doesn't freeze, and if it does, it reboots your computer
-	  after a certain amount of time.
+	  (and likely others). The driver also supports the W83627DHG chip.
+	  This watchdog simply watches your kernel to make sure it doesn't
+	  freeze, and if it does, it reboots your computer after a certain
+	  amount of time.
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called w83627hf_wdt.

drivers/watchdog/w83627hf_wdt.c

@@ -42,7 +42,7 @@
 
 #include <asm/system.h>
 
-#define WATCHDOG_NAME "w83627hf/thf/hg WDT"
+#define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT"
 #define PFX WATCHDOG_NAME ": "
 #define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */
 
@@ -89,7 +89,7 @@ static void w83627hf_select_wd_register(void)
 		c = ((inb_p(WDT_EFDR) & 0xf7) | 0x04); /* select WDT0 */
 		outb_p(0x2b, WDT_EFER);
 		outb_p(c, WDT_EFDR);	/* set GPIO3 to WDT0 */
-	} else if (c == 0x88) {	/* W83627EHF */
+	} else if (c == 0x88 || c == 0xa0) {	/* W83627EHF / W83627DHG */
 		outb_p(0x2d, WDT_EFER); /* select GPIO5 */
 		c = inb_p(WDT_EFDR) & ~0x01; /* PIN77 -> WDT0# */
 		outb_p(0x2d, WDT_EFER);
@@ -321,7 +321,7 @@ static int __init wdt_init(void)
 {
 	int ret;
 
-	printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG Super I/O chip initialising.\n");
+	printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG/DHG Super I/O chip initialising.\n");
 
 	if (wdt_set_heartbeat(timeout)) {
 		wdt_set_heartbeat(WATCHDOG_TIMEOUT);