hwmon: (it87) Enhance validation for fan4 and fan5

Several of the chips supported by this driver have a configuration
register to enable fan4 and fan5. Use those registers to determine
if fan4 and fan5 tachometers are supported.

Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c
index f40d81a0a9fc55fe9474c8df85eb3478b65a3fe7..5adb269918fb554c90c6e21ee08657a9a4e13261 100644 (file)
--- a/drivers/hwmon/it87.c
+++ b/drivers/hwmon/it87.c
@@ -2415,6 +2415,29 @@ static int __init it87_find(int sioaddr, unsigned short *address,
 
                superio_select(sioaddr, GPIO);
 
+               /* Check for fan4, fan5 */
+               if (has_five_fans(config)) {
+                       reg = superio_inb(sioaddr, IT87_SIO_GPIO2_REG);
+                       switch (sio_data->type) {
+                       case it8718:
+                               if (reg & BIT(5))
+                                       sio_data->skip_fan |= BIT(3);
+                               if (reg & BIT(4))
+                                       sio_data->skip_fan |= BIT(4);
+                               break;
+                       case it8720:
+                       case it8721:
+                       case it8728:
+                               if (!(reg & BIT(5)))
+                                       sio_data->skip_fan |= BIT(3);
+                               if (!(reg & BIT(4)))
+                                       sio_data->skip_fan |= BIT(4);
+                               break;
+                       default:
+                               break;
+                       }
+               }
+
                reg = superio_inb(sioaddr, IT87_SIO_GPIO3_REG);
                if (!sio_data->skip_vid) {
                        /* We need at least 4 VID pins */