[PATCH] watchdog: f71808e_wdt: Add F81866 support

["Ji-Ze Hong (Peter Hong)" <hpeter@gmail.com>]

Adds watchdog enable support for Fintek F81866 Super-IO chip to
Fintek wdt driver (f71808e_wdt)

Tested and verified on iBASE MI802 Industrial PC

Datasheet references:
http://www.alldatasheet.com/datasheet-pdf/pdf/459085/FINTEK/F81866AD-I.html

Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
---
 drivers/watchdog/f71808e_wdt.c | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/f71808e_wdt.c b/drivers/watchdog/f71808e_wdt.c
index d4ba262..bb905da 100644
--- a/drivers/watchdog/f71808e_wdt.c
+++ b/drivers/watchdog/f71808e_wdt.c
@@ -51,6 +51,17 @@
 #define SIO_REG_ENABLE		0x30	/* Logical device enable */
 #define SIO_REG_ADDR		0x60	/* Logical device address (2 bytes) */
 
+#define SIO_REG_PORT_SEL	0x27	/* F81866 Multi-Function Register */
+#define SIO_REG_GPIO1		0x2c	/*
+					 * GPIO1 Control Register when 27h
+					 * BIT3:2 = 01 & BIT0 = 0
+					 *
+					 * The PIN 70(GPIO15/WDTRST) is
+					 * controlled by 2Ch:
+					 * BIT5: 0 -> WDTRST#
+					 *       1 -> GPIO15
+					 */
+
 #define SIO_FINTEK_ID		0x1934	/* Manufacturers ID */
 #define SIO_F71808_ID		0x0901	/* Chipset ID */
 #define SIO_F71858_ID		0x0507	/* Chipset ID */
@@ -60,6 +71,7 @@
 #define SIO_F71882_ID		0x0541	/* Chipset ID */
 #define SIO_F71889_ID		0x0723	/* Chipset ID */
 #define SIO_F81865_ID		0x0704	/* Chipset ID */
+#define SIO_F81866_ID		0x1010	/* Chipset ID */
 
 #define F71808FG_REG_WDO_CONF		0xf0
 #define F71808FG_REG_WDT_CONF		0xf5
@@ -116,7 +128,8 @@ module_param(start_withtimeout, uint, 0);
 MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
 	" given initial timeout. Zero (default) disables this feature.");
 
-enum chips { f71808fg, f71858fg, f71862fg, f71869, f71882fg, f71889fg, f81865 };
+enum chips { f71808fg, f71858fg, f71862fg, f71869, f71882fg, f71889fg, f81865,
+	     f81866};
 
 static const char *f71808e_names[] = {
 	"f71808fg",
@@ -126,6 +139,7 @@ static const char *f71808e_names[] = {
 	"f71882fg",
 	"f71889fg",
 	"f81865",
+	"f81866",
 };
 
 /* Super-I/O Function prototypes */
@@ -370,6 +384,13 @@ static int watchdog_start(void)
 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 5);
 		break;
 
+	case f81866:
+		/* Set pin 70 to WDTRST# */
+		superio_clear_bit(watchdog.sioaddr, SIO_REG_PORT_SEL, 9);
+		superio_set_bit(watchdog.sioaddr, SIO_REG_PORT_SEL, 4);
+		superio_clear_bit(watchdog.sioaddr, SIO_REG_GPIO1, 0x20);
+		break;
+
 	default:
 		/*
 		 * 'default' label to shut up the compiler and catch
@@ -382,7 +403,7 @@ static int watchdog_start(void)
 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
 	superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
 
-	if (watchdog.type == f81865)
+	if (watchdog.type == f81865 || watchdog.type == f81866)
 		superio_set_bit(watchdog.sioaddr, F81865_REG_WDO_CONF,
 				F81865_FLAG_WDOUT_EN);
 	else
@@ -788,6 +809,9 @@ static int __init f71808e_find(int sioaddr)
 	case SIO_F81865_ID:
 		watchdog.type = f81865;
 		break;
+	case SIO_F81866_ID:
+		watchdog.type = f81866;
+		break;
 	default:
 		pr_info("Unrecognized Fintek device: %04x\n",
 			(unsigned int)devid);
-- 
1.9.1