[PATCH 4/4] Documentation: Add device tree bindings for Freescale FTM PWM

[s.hauer@pengutronix.de (Sascha Hauer)]

On Thu, Aug 22, 2013 at 02:55:42AM +0000, Xiubo Li-B47053 wrote:
> Hi Tomasz,
> 
> Thanks for your comments.
> 
> 
> > Could you explain meaning of this property more precisely? I'm interested
> > especially how is this related to the PWM IP block and boards.
> > 
> 
> Yes.
> There are 8 channels most. While the pinctrls of 4th and 5th channels could be
> used by uart's Rx and Tx, then these 2 channels won't be used for pwm output,
> so there will be 6 channels available by the pwm.
> Thus, the pwm chip will register only 6 pwms(6 channels) most("fsl,pwm-channel-orders
> = {0 1 2 3 6 7}").And also the "fsl,pwm-channel-number" will be 6.

If the chip has eight PWMs I would register all of them. If some of them
are not routed out by the pinmux then just nothing happens if you use
them. In a sane devicetree they won't be referenced anyway when they are
not routed out of the SoC.

Sascha

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