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

On Wed, Feb 08, 2012 at 09:15:08AM +0100, Thierry Reding wrote:

* Ryan Mallon wrote:

quoted

On 07/02/12 02:19, Thierry Reding wrote:

quoted

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

It would be better to make the code handle arbitrary numbers of PWMs. A
Kconfig knob becomes annoying when you have more than one platform
configured into the kernel.

AFAICT handling an arbitrary number of PWMs will only be possible once we get
rid of the global namespace and therefore should be postponed for later. I
may be wrong, though, so if anybody can point me in the right direction I'm
perfectly happy to change that in this series.

One solution would be to look at how genirq handles this.  Eg, it uses a
radix tree to store the irqdescs rather than an array, and a bitmap
showing which global numbers are allocated.