On Sun, 2015-11-22 at 13:03 +0000, Måns Rullgård wrote:

Andy Shevchenko [off-list ref] writes:

quoted

The SATA implementation based on two actually different devices,
i.e. SATA and
DMA controllers.

For Synopsys DesignWare DMA we have already a generic
implementation of the
driver. Thus, the patch converts the code to use DMAEngine
framework and
dw_dmac driver.

In future it will be better to split the devices inside DTS as well
like it's
done on other platforms.

quoted

@@ -1721,16 +1227,16 @@ static int sata_dwc_probe(struct

platform_device *ofdev)
 		   idr, ver[0], ver[1], ver[2]);

 	/* Get SATA DMA interrupt number */
-	irq = irq_of_parse_and_map(np, 1);
-	if (irq == NO_IRQ) {
+	hsdev->dma->irq = irq_of_parse_and_map(np, 1);

This doesn't look like it has been more than compile-tested.

Yes, that's true, my question [1] was a crying in the wilderness.

  Nothing
ever allocates hsdev->dma, so it can't possibly work.

You are right.

Also, has anyone given any thought to getting rid of the dependency
on
the DW DMA controller?

How? Before it was even more harder link to it (embedded routines).

On the other hand you may introduce dma_ops and use them like it's
done, for example, in spi-dw*.c

  Presumably support for old device trees would
need to be retained for compatibility.  Maybe checking for a "dmas"
property and falling back on the current behaviour if it's missing.  

I didn't get how DT is related to DW or any other DMAC used with this
SATA controller.

My
goal is to get this driver working with another chip using the same
SATA
controller but a different DMA engine.

It would be nice to eventually bring this working with generic DMA
Engine API. Please, keep me in Cc list regarding this driver.

[1] https://lkml.org/lkml/2014/12/12/547

-- 
Andy Shevchenko [off-list ref]
Intel Finland Oy