From: Amelie Delaunay <amelie.delaunay@foss.st.com>
To: Vinod Koul <vkoul@kernel.org>, Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: <dmaengine@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<devicetree@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
Amelie Delaunay <amelie.delaunay@foss.st.com>
Subject: [PATCH v3 4/9] dt-bindings: dma: stm32-dma3: prevent additional transfers
Date: Wed, 16 Oct 2024 14:39:56 +0200 [thread overview]
Message-ID: <20241016-dma3-mp25-updates-v3-4-8311fe6f228d@foss.st.com> (raw)
In-Reply-To: <20241016-dma3-mp25-updates-v3-0-8311fe6f228d@foss.st.com>
Some devices require a single transfer. For example, reading FMC ECC status
registers does not support multiple transfers.
Add the possibility to prevent additional transfers, by setting bit 17 of
the 'DMA transfer requirements' bit mask.
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
Changes in v3:
- Refine commit description as per Rob's suggestion.
Changes in v2:
- Reword commit title/message/content as per Rob's suggestion.
---
Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml | 3 +++
1 file changed, 3 insertions(+)
diff --git a/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml b/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml
index 5484848735f8ac3d2050104bbab1d986e82ba6a7..36f9fe860eb990e6caccedd31460ee6993772a35 100644
--- a/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml
+++ b/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml
@@ -99,6 +99,9 @@ properties:
-bit 16: Prevent packing/unpacking mode
0x0: pack/unpack enabled when source data width/burst != destination data width/burst
0x1: memory data width/burst forced to peripheral data width/burst to prevent pack/unpack
+ -bit 17: Prevent additional transfers due to linked-list refactoring
+ 0x0: don't prevent additional transfers for optimal performance
+ 0x1: prevent additional transfer to accommodate user constraints such as single transfer
required:
- compatible
--
2.25.1
next prev parent reply other threads:[~2024-10-16 12:43 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-16 12:39 [PATCH v3 0/9] STM32 DMA3 updates for STM32MP25 Amelie Delaunay
2024-10-16 12:39 ` [PATCH v3 1/9] dt-bindings: dma: stm32-dma3: prevent packing/unpacking mode Amelie Delaunay
2024-10-16 12:39 ` [PATCH v3 2/9] dmaengine: stm32-dma3: prevent pack/unpack thanks to DT configuration Amelie Delaunay
2024-10-16 12:39 ` [PATCH v3 3/9] dmaengine: stm32-dma3: refactor HW linked-list to optimize memory accesses Amelie Delaunay
2024-10-16 12:39 ` Amelie Delaunay [this message]
2024-10-16 17:33 ` [PATCH v3 4/9] dt-bindings: dma: stm32-dma3: prevent additional transfers Rob Herring (Arm)
2024-10-16 12:39 ` [PATCH v3 5/9] dmaengine: stm32-dma3: prevent LL refactoring thanks to DT configuration Amelie Delaunay
2024-10-16 12:39 ` [PATCH v3 6/9] dmaengine: stm32-dma3: clamp AXI burst using match data Amelie Delaunay
2024-10-16 12:39 ` [PATCH v3 7/9] arm64: dts: st: add DMA support on U(S)ART instances of stm32mp25 Amelie Delaunay
2024-10-16 12:40 ` [PATCH v3 8/9] arm64: dts: st: add DMA support on I2C " Amelie Delaunay
2024-10-16 12:40 ` [PATCH v3 9/9] arm64: dts: st: add DMA support on SPI " Amelie Delaunay
2024-10-22 5:32 ` (subset) [PATCH v3 0/9] STM32 DMA3 updates for STM32MP25 Vinod Koul
2024-10-29 16:09 ` Alexandre TORGUE
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