[PATCH v3 3/7] dt-bindings: stm32-mdma: Add DMA/MDMA chaining support bindings

From: Pierre-Yves MORDRET
Date: Fri Sep 28 2018 - 09:02:53 EST


From: M'boumba Cedric Madianga <cedric.madianga@xxxxxxxxx>

This patch adds the description of the 2 properties needed to support M2M
transfer triggered by STM32 DMA when his transfer is complete.

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@xxxxxx>
---
Version history:
v3:
v2:
* rework content
v1:
* Initial
---
---
Documentation/devicetree/bindings/dma/stm32-mdma.txt | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/dma/stm32-mdma.txt b/Documentation/devicetree/bindings/dma/stm32-mdma.txt
index d18772d..27c2812 100644
--- a/Documentation/devicetree/bindings/dma/stm32-mdma.txt
+++ b/Documentation/devicetree/bindings/dma/stm32-mdma.txt
@@ -10,7 +10,7 @@ Required properties:
- interrupts: Should contain the MDMA interrupt.
- clocks: Should contain the input clock of the DMA instance.
- resets: Reference to a reset controller asserting the DMA controller.
-- #dma-cells : Must be <5>. See DMA client paragraph for more details.
+- #dma-cells : Must be <6>. See DMA client paragraph for more details.

Optional properties:
- dma-channels: Number of DMA channels supported by the controller.
@@ -26,7 +26,7 @@ Example:
interrupts = <122>;
clocks = <&timer_clk>;
resets = <&rcc 992>;
- #dma-cells = <5>;
+ #dma-cells = <6>;
dma-channels = <16>;
dma-requests = <32>;
st,ahb-addr-masks = <0x20000000>, <0x00000000>;
@@ -35,8 +35,8 @@ Example:
* DMA client

DMA clients connected to the STM32 MDMA controller must use the format
-described in the dma.txt file, using a five-cell specifier for each channel:
-a phandle to the MDMA controller plus the following five integer cells:
+described in the dma.txt file, using a six-cell specifier for each channel:
+a phandle to the MDMA controller plus the following six integer cells:

1. The request line number
2. The priority level
@@ -76,6 +76,10 @@ a phandle to the MDMA controller plus the following five integer cells:
if no HW ack signal is used by the MDMA client
5. A 32bit mask specifying the value to be written to acknowledge the request
if no HW ack signal is used by the MDMA client
+6. A bitfield value specifying if the MDMA client wants to generate M2M
+ transfer with HW trigger (1) or not (0). This bitfield should be only
+ enabled for M2M transfer triggered by STM32 DMA client. The memory devices
+ involved in this kind of transfer are SRAM and DDR.

Example:

--
2.7.4