hwmon: (nct6775) Improve fan detection

Recent chips support multiple pins for fan speed inputs and fan control
outputs. Examine all of them to determine supported fan controls.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/nct6775.c b/drivers/hwmon/nct6775.c
index 318e0c5a34c8400d5aeb2c6364fcf6a463bc1284..4667691ca6a8dd9a891c461d2108aa12e4359db0 100644 (file)
--- a/drivers/hwmon/nct6775.c
+++ b/drivers/hwmon/nct6775.c
@@ -105,6 +105,7 @@ MODULE_PARM_DESC(fan_debounce, "Enable debouncing for fan RPM signal");
 #define NCT6775_LD_ACPI                0x0a
 #define NCT6775_LD_HWM         0x0b
 #define NCT6775_LD_VID         0x0d
+#define NCT6775_LD_12          0x12
 
 #define SIO_REG_LDSEL          0x07    /* Logical device select */
 #define SIO_REG_DEVID          0x20    /* Device ID (2 bytes) */
@@ -3392,6 +3393,8 @@ nct6775_check_fan_inputs(struct nct6775_data *data)
                pwm5pin = false;
                pwm6pin = false;
        } else {        /* NCT6779D, NCT6791D, NCT6792D, or NCT6793D */
+               int regval_1b, regval_2a, regval_eb;
+
                regval = superio_inb(sioreg, 0x1c);
 
                fan3pin = !(regval & BIT(5));
@@ -3402,17 +3405,43 @@ nct6775_check_fan_inputs(struct nct6775_data *data)
                pwm4pin = !(regval & BIT(1));
                pwm5pin = !(regval & BIT(2));
 
-               fan4min = fan4pin;
-
-               if (data->kind == nct6791 || data->kind == nct6792 ||
-                   data->kind == nct6793) {
-                       regval = superio_inb(sioreg, 0x2d);
-                       fan6pin = (regval & BIT(1));
-                       pwm6pin = (regval & BIT(0));
-               } else {        /* NCT6779D */
+               regval = superio_inb(sioreg, 0x2d);
+               switch (data->kind) {
+               case nct6791:
+               case nct6792:
+                       fan6pin = regval & BIT(1);
+                       pwm6pin = regval & BIT(0);
+                       break;
+               case nct6793:
+                       regval_1b = superio_inb(sioreg, 0x1b);
+                       regval_2a = superio_inb(sioreg, 0x2a);
+
+                       if (!pwm5pin)
+                               pwm5pin = regval & BIT(7);
+                       fan6pin = regval & BIT(1);
+                       pwm6pin = regval & BIT(0);
+                       if (!fan5pin)
+                               fan5pin = regval_1b & BIT(5);
+
+                       superio_select(sioreg, NCT6775_LD_12);
+                       regval_eb = superio_inb(sioreg, 0xeb);
+                       if (!fan5pin)
+                               fan5pin = regval_eb & BIT(5);
+                       if (!pwm5pin)
+                               pwm5pin = (regval_eb & BIT(4)) &&
+                                          !(regval_2a & BIT(0));
+                       if (!fan6pin)
+                               fan6pin = regval_eb & BIT(3);
+                       if (!pwm6pin)
+                               pwm6pin = regval_eb & BIT(2);
+                       break;
+               default:        /* NCT6779D */
                        fan6pin = false;
                        pwm6pin = false;
+                       break;
                }
+
+               fan4min = fan4pin;
        }
 
        /* fan 1 and 2 (0x03) are always present */