PWM and Tachometer

The WPCM450 supports pulse-width modulation (PWM) output and fan speed measurement (in the "fan tachometer").

device	MMIO	IRQ	comments
tacho 0	0xb8004000	24
tacho 1	0xb8005000	25
PWM	0xb8007000	28
more PWM	0xb8007100	28	requires at least chip version Z2

PWM

There are four PWM channels per PWM module. Before chip version Z2, there is only one module, but from Z2 there are two. On NPCM750, the PWM modules are 0x1000 bytes apart, but on WPCM450 they are 0x100 bytes apart.

Tacho

There are two tacho modules (vs. eight on NPCM750).

References

• Dell drivers: fan tacho (header), PWM (header)
• Combined tacho/PWM mainline driver for NPCM750