Thread (13 messages) flat view 13 messages, 3 authors, 2016-11-16

Re: [PATCH 4/4] Update device tree Synopsys DW DMAC documentation

From: Andy Shevchenko <hidden>
Date: 2016-11-16 15:13:50
Also in: lkml

On Wed, 2016-11-16 at 16:56 +0300, Eugeniy Paltsev wrote:
quoted hunk ↗ jump to hunk
 * Rename is_private to is-private as ordered by DT policy.
 The change leaves the support for the old format.

 * Add is-memcpu property, so it is possible to
 enable memory-to-memory transfers support via DT.

 * Add hw-llp property, so it is possible to enable
 hardware multi block transfers support via DT.

 Fix white spaces.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev-HKixBCOQz3hWk0Htik3J/w@public.gmane.org>
---
 Documentation/devicetree/bindings/dma/snps-dma.txt | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/Documentation/devicetree/bindings/dma/snps-dma.txt
b/Documentation/devicetree/bindings/dma/snps-dma.txt
index 0f55832..d41d960 100644
--- a/Documentation/devicetree/bindings/dma/snps-dma.txt
+++ b/Documentation/devicetree/bindings/dma/snps-dma.txt
@@ -20,13 +20,19 @@ Required properties:
 Deprecated properties:
 - data_width: Maximum data width supported by hardware per AHB master
   (0 - 8bits, 1 - 16bits, ..., 5 - 256bits)
+- is_private: The device channels should be marked as private and not
for by the
+  general purpose DMA channel allocator. False if not passed.
This...
 
 
 Optional properties:
 - interrupt-parent: Should be the phandle for the interrupt
controller
   that services interrupts for this device
-- is_private: The device channels should be marked as private and not
for by the
+- is-private: The device channels should be marked as private and not
for by the
   general purpose DMA channel allocator. False if not passed.
...and this is a part of patch 1.
+- is-memcpu: The device channels do support memory-to-memory 
memcpy
transfers. 
False
+  if not passed.
+- hw-llp: Multi block transfers supported by hardware per AHB master.
+  0 (default): not supported, 1: supported.
Overall, since we are going to expose some properties to the Device Tree
I would really think twice about naming. Better if we reuse something
existing already.

So, what I can see is

dmacap,private
dmacap,memcpy

Here is a selling point as well, i.e. standardization.

'hw-llp' sounds too tricky, perhaps 'multi-block' is better and could be
re-used.
quoted hunk ↗ jump to hunk
 
 Example:
 
@@ -56,7 +62,7 @@ The four cells in order are:
 4. Peripheral master for transfers on allocated channel
 
 Example:
-	
+
No, no need to touch this.

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