Since some DW DMA controllers (like one installed on Baikal-T1 SoC) may
have non-uniform DMA capabilities per device channels, let's add
the DW DMA specific device_caps callback to expose that specifics up to
the DMA consumer. It's a dummy function for now. We'll fill it in with
capabilities overrides in the next commits.

Signed-off-by: Serge Semin <redacted>
Cc: Alexey Malahov <redacted>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org

---

Changelog v3:
- This is a new patch created as a result of the discussion with Vinud and
  Andy in the framework of DW DMA burst and LLP capabilities.
---
 drivers/dma/dw/core.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index fb95920c429e..ceded21537e2 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c

@@ -1049,6 +1049,11 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
 	dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
 }
 
+static void dwc_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
+{
+
+}
+
 int do_dma_probe(struct dw_dma_chip *chip)
 {
 	struct dw_dma *dw = chip->dw;

@@ -1214,6 +1219,7 @@ int do_dma_probe(struct dw_dma_chip *chip)
 	dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
 	dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
 
+	dw->dma.device_caps = dwc_caps;
 	dw->dma.device_config = dwc_config;
 	dw->dma.device_pause = dwc_pause;
 	dw->dma.device_resume = dwc_resume;

-- 
2.26.2