Commit 2d99925a15b6 ("hwmon: (nct6775) Separate fan/pwm configuration
detection for NCT6793D") accidentally removed part of the code detecting
if fan6 is enabled or not. As result, fan6 is no longer detected on Asus
PRIME Z370-A. Restore the missing detection code.

Fixes: 2d99925a15b6 ("hwmon: (nct6775) Separate fan/pwm configuration detection for NCT6793D")
Reported-by: Chris Siebenmann <cks@cs.toronto.edu>
Cc: Chris Siebenmann <cks@cs.toronto.edu>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Similar to other recent chips from Nuvoton, IO mapping may be disabled
by default. Enable it when instantiating the driver and after resume.

Fixes: 0599682b826f ("hwmon: (nct6775) Add support for NCT6798D")
Fixes: e41da286a2fd ("hwmon: (nct6775) Add support for NCT6797D")
Reported-by: Michael Cook <mcook@mackal.net>
Cc: Michael Cook <mcook@mackal.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

The chip ID is 0xd42[8-f], not 0xd45[8-f].

Fixes: 0599682b826f ("hwmon: (nct6775) Add support for NCT6798D")
Reported-by: Michael Cook <mcook@mackal.net>
Cc: Michael Cook <mcook@mackal.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

NCT6798D is, with the exception of fan and pwm channel configuration
registers, similar to other chips of the series. One interesting
difference is the chip ID, which is now extended to 13 bit (the 12-bit
chip ID value overlaps with the chip ID of NCT6797D).

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

Add support for NCT6797D. With the exception of fan/pwm configuration
registers, it is mostly compatible with NCT6795D.

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

For NCT6795D and NCT6796D, the DIMM temperature sources are named
"Agent[01] Dimm [01]" per datasheet. Match names in datasheets to
avoid confusion.

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

Now that everything is separated, clean up fan and pwm configuration
for NCT6796D. While doing that, take the forgotten configuration register
cre0 into account to determine if AUXFANIN2 (fan5) and AUXFANOUT2 (pwm5)
are connected.

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

Separate fan/pwm configuration detection for NCT6795D into separate
case statement to make the code easier to read.

No functional change.

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

While detecting the configuration for multiple chips in one go reduces
code size, it also increases code complexity. Separate chip detection
to improve code readability. As first step, separate detection for
NCT6793D.

No functional change.

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

Per datasheet, AUXFANIN3 (fan6) and AUXFANOUT3 (pwm6) are only connected
if DSW_EN is false.

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