On 14.01.2016, at 05:07, Vinod Koul [off-list ref] wrote:

On Wed, Jan 13, 2016 at 03:24:59PM +0100, Martin Sperl wrote:

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But that would be frowned upon, so I had to come up with the approach
taken, which makes the following assumptions:

DT was designed to move this info and hardcoding from kernel into
DT, so why cant we do that?

We still need to be backwards-compatible - at least that is what
everyone tells me, so I need to hard-code fallbacks for those values.

IMO hard code for falling back is okay as that supports old cases and new
platforms use geric DT info and new devices can be supported generically,
please check with DT folks..

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* the DT maps only the interrupts that are assigned to the HW block
* the driver knows about the number of DMA channels in HW

that could be a DT property, yes.

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* the driver knows about the mapping of shared interrupts
 (11-14 share irq).

OK - how would you define that "mapping" in a "sane" manner in the DT
that allows us to have multiple such mappings in the future?

You are hard coding the flags for each channel, we can pass this for each
channel in the interrupt configi, a flag share/none..? Please run this thru
DT experts and I am not one of them..

So here a ?simple? approach with the following device tree addition (plus defaults):
	interrupts = <1 16>, /* dma 0 irq */
		     <1 17>, /* dma 1 irq */
	...
		     <1 26>, /* dma 10 irq */
		     <1 27>, /* dma 11-14 irq */
		     <1 28>; /* dma all irq */
	brcm,dma-channel-mask = <0x7f35>;
	/* new properties below - also the defaults */
	brcm,dma-channel-shared-mask = <0x7800>;
	brcm,dma-shared-irq-index = <11>;

Is this sufficient to move forward?

Thanks,
	Martin

P.s: this would also mean (for later patches):
	brcm,dma-lite-channel-mask = <0x7f00>;