watchdog: add f71862fg support

Watchdog support for Fintek F71862fg Super-I/O added.
Two different hardware reset pins of the F71862fg chip can be configured 
by an additional module parameter.

Signed-off-by: Lutz Ballaschke <vegan.grindcore@googlemail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/f71808e_wdt.c

@@ -42,6 +42,7 @@
 #define SIO_REG_DEVID		0x20	/* Device ID (2 bytes) */
 #define SIO_REG_DEVREV		0x22	/* Device revision */
 #define SIO_REG_MANID		0x23	/* Fintek ID (2 bytes) */
+#define SIO_REG_ROM_ADDR_SEL	0x27	/* ROM address select */
 #define SIO_REG_MFUNCT1		0x29	/* Multi function select 1 */
 #define SIO_REG_MFUNCT2		0x2a	/* Multi function select 2 */
 #define SIO_REG_MFUNCT3		0x2b	/* Multi function select 3 */
@@ -71,6 +72,8 @@
 #define WATCHDOG_MAX_TIMEOUT	(60 * 255)
 #define WATCHDOG_PULSE_WIDTH	125	/* 125 ms, default pulse width for
 					   watchdog signal */
+#define WATCHDOG_F71862FG_PIN	63	/* default watchdog reset output
+					   pin number 63 */
 
 static unsigned short force_id;
 module_param(force_id, ushort, 0);
@@ -90,6 +93,12 @@ MODULE_PARM_DESC(pulse_width,
 	"Watchdog signal pulse width. 0(=level), 1 ms, 25 ms, 125 ms or 5000 ms"
 			" (default=" __MODULE_STRING(WATCHDOG_PULSE_WIDTH) ")");
 
+static unsigned int f71862fg_pin = WATCHDOG_F71862FG_PIN;
+module_param(f71862fg_pin, uint, 0);
+MODULE_PARM_DESC(f71862fg_pin,
+	"Watchdog f71862fg reset output pin configuration. Choose pin 56 or 63"
+			" (default=" __MODULE_STRING(WATCHDOG_F71862FG_PIN)")");
+
 static int nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, bool, 0444);
 MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
@@ -283,6 +292,28 @@ exit_unlock:
 	return err;
 }
 
+static int f71862fg_pin_configure(unsigned short ioaddr)
+{
+	/* When ioaddr is non-zero the calling function has to take care of
+	   mutex handling and superio preparation! */
+
+	if (f71862fg_pin == 63) {
+		if (ioaddr) {
+			/* SPI must be disabled first to use this pin! */
+			superio_clear_bit(ioaddr, SIO_REG_ROM_ADDR_SEL, 6);
+			superio_set_bit(ioaddr, SIO_REG_MFUNCT3, 4);
+		}
+	} else if (f71862fg_pin == 56) {
+		if (ioaddr)
+			superio_set_bit(ioaddr, SIO_REG_MFUNCT1, 1);
+	} else {
+		printk(KERN_ERR DRVNAME ": Invalid argument f71862fg_pin=%d\n",
+				f71862fg_pin);
+		return -EINVAL;
+	}
+	return 0;
+}
+
 static int watchdog_start(void)
 {
 	/* Make sure we don't die as soon as the watchdog is enabled below */
@@ -304,6 +335,12 @@ static int watchdog_start(void)
 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 3);
 		break;
 
+	case f71862fg:
+		err = f71862fg_pin_configure(watchdog.sioaddr);
+		if (err)
+			goto exit_superio;
+		break;
+
 	case f71882fg:
 		/* Set pin 56 to WDTRST# */
 		superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 1);
@@ -712,16 +749,16 @@ static int __init f71808e_find(int sioaddr)
 	case SIO_F71808_ID:
 		watchdog.type = f71808fg;
 		break;
+	case SIO_F71862_ID:
+		watchdog.type = f71862fg;
+		err = f71862fg_pin_configure(0); /* validate module parameter */
+		break;
 	case SIO_F71882_ID:
 		watchdog.type = f71882fg;
 		break;
 	case SIO_F71889_ID:
 		watchdog.type = f71889fg;
 		break;
-	case SIO_F71862_ID:
-		/* These have a watchdog, though it isn't implemented (yet). */
-		err = -ENOSYS;
-		goto exit;
 	case SIO_F71858_ID:
 		/* Confirmed (by datasheet) not to have a watchdog. */
 		err = -ENODEV;