[PATCH v2 02/10] pwm: Allow chips to support multiple PWMs.

On 02/06/2012 04:19 PM, Thierry Reding wrote:

This commit modifies the PWM core to support multiple PWMs per struct
pwm_chip.

I think you should mention what motivates this change.

It achieves this in a similar way to how gpiolib works, by
allowing PWM ranges to be requested dynamically (pwm_chip.base == -1) or
starting at a given offset (pwm_chip.base >= 0).

If we've learned one thing from gpiolib, I think it is that using a global
index to identify a resource was a bad idea.

A chip specifies how
many PWMs it controls using the npwm member. Each of the functions in
the pwm_ops structure gets an additional argument that specified the PWM
number (it can be converted to a per-chip index by subtracting the
chip's base).

The total maximum number of PWM devices is currently fixed to 64, but
can easily be made configurable via Kconfig.

The code says 1024.

The patch is incomplete in that it doesn't convert any existing drivers
that are now broken.