From: "Clément Le Goffic" <legoffic.clement@gmail.com>
To: Krzysztof Kozlowski <krzk@kernel.org>,
Rob Herring <robh@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Julius Werner <jwerner@chromium.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
linux-stm32@st-md-mailman.stormreply.com,
linux-arm-kernel@lists.infradead.org,
"Clément Le Goffic" <legoffic.clement@gmail.com>,
"Clément Le Goffic" <clement.legoffic@foss.st.com>
Subject: [PATCH v9 3/7] dt-bindings: memory: factorise LPDDR channel binding into SDRAM channel
Date: Tue, 18 Nov 2025 16:07:59 +0100 [thread overview]
Message-ID: <20251118-b4-ddr-bindings-v9-3-a033ac5144da@gmail.com> (raw)
In-Reply-To: <20251118-b4-ddr-bindings-v9-0-a033ac5144da@gmail.com>
From: Clément Le Goffic <clement.legoffic@foss.st.com>
LPDDR, DDR and so SDRAM channels exist and share the same properties, they
have a compatible, ranks, and an io-width.
Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Clément Le Goffic <legoffic.clement@gmail.com>
---
...lpddr-channel.yaml => jedec,sdram-channel.yaml} | 23 +++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)
diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr-channel.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,sdram-channel.yaml
similarity index 83%
rename from Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr-channel.yaml
rename to Documentation/devicetree/bindings/memory-controllers/ddr/jedec,sdram-channel.yaml
index 34b5bd153f63..9892da520fe4 100644
--- a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr-channel.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,sdram-channel.yaml
@@ -1,16 +1,17 @@
# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
-$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr-channel.yaml#
+$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,sdram-channel.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
-title: LPDDR channel with chip/rank topology description
+title: SDRAM channel with chip/rank topology description
description:
- An LPDDR channel is a completely independent set of LPDDR pins (DQ, CA, CS,
- CK, etc.) that connect one or more LPDDR chips to a host system. The main
- purpose of this node is to overall LPDDR topology of the system, including the
- amount of individual LPDDR chips and the ranks per chip.
+ A memory channel of SDRAM memory like DDR SDRAM or LPDDR SDRAM is a completely
+ independent set of pins (DQ, CA, CS, CK, etc.) that connect one or more memory
+ chips to a host system. The main purpose of this node is to overall memory
+ topology of the system, including the amount of individual memory chips and
+ the ranks per chip.
maintainers:
- Julius Werner <jwerner@chromium.org>
@@ -26,14 +27,14 @@ properties:
io-width:
description:
The number of DQ pins in the channel. If this number is different
- from (a multiple of) the io-width of the LPDDR chip, that means that
+ from (a multiple of) the io-width of the SDRAM chip, that means that
multiple instances of that type of chip are wired in parallel on this
channel (with the channel's DQ pins split up between the different
chips, and the CA, CS, etc. pins of the different chips all shorted
together). This means that the total physical memory controlled by a
channel is equal to the sum of the densities of each rank on the
- connected LPDDR chip, times the io-width of the channel divided by
- the io-width of the LPDDR chip.
+ connected SDRAM chip, times the io-width of the channel divided by
+ the io-width of the SDRAM chip.
enum:
- 8
- 16
@@ -51,8 +52,8 @@ patternProperties:
"^rank@[0-9]+$":
type: object
description:
- Each physical LPDDR chip may have one or more ranks. Ranks are
- internal but fully independent sub-units of the chip. Each LPDDR bus
+ Each physical SDRAM chip may have one or more ranks. Ranks are
+ internal but fully independent sub-units of the chip. Each SDRAM bus
transaction on the channel targets exactly one rank, based on the
state of the CS pins. Different ranks may have different densities and
timing requirements.
--
2.43.0
next prev parent reply other threads:[~2025-11-18 15:09 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-18 15:07 [PATCH v9 0/7] Add DDR4 memory-controller bindings and factorise LPDDR and DDR bindings Clément Le Goffic
2025-11-18 15:07 ` [PATCH v9 1/7] dt-bindings: memory: factorise LPDDR props into SDRAM props Clément Le Goffic
2025-11-18 15:07 ` [PATCH v9 2/7] dt-bindings: memory: introduce DDR4 Clément Le Goffic
2025-11-20 14:57 ` Rob Herring (Arm)
2025-11-18 15:07 ` Clément Le Goffic [this message]
2025-11-18 15:08 ` [PATCH v9 4/7] dt-binding: memory: add DDR4 channel compatible Clément Le Goffic
2025-11-18 15:08 ` [PATCH v9 5/7] dt-bindings: memory: SDRAM channel: standardise node name Clément Le Goffic
2025-11-18 15:08 ` [PATCH v9 6/7] arm64: dts: st: add LPDDR channel to stm32mp257f-dk board Clément Le Goffic
2025-11-18 15:08 ` [PATCH v9 7/7] arm64: dts: st: add DDR channel to stm32mp257f-ev1 board Clément Le Goffic
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