2021-03-24 21:44:24

by Julius Werner

Subject: [PATCH] dt-bindings: ddr: Add optional manufacturer and revision ID to LPDDR3

On some platforms, DDR parts are multi-sourced and the exact part number
used is not know to either kernel or firmware at build time. Firmware
can read identifying information from DDR mode registers at boot time
but needs a way to communicate this information to kernel and/or
userspace. This patch adds optional properties for this information to
the existing "jedec,lpddr3" device tree binding to be used for that
purpose.

Signed-off-by: Julius Werner <[email protected]>
---
Documentation/devicetree/bindings/ddr/lpddr3.txt | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/ddr/lpddr3.txt b/Documentation/devicetree/bindings/ddr/lpddr3.txt
index a0eda35a86eef9..b221e653d3845e 100644
--- a/Documentation/devicetree/bindings/ddr/lpddr3.txt
+++ b/Documentation/devicetree/bindings/ddr/lpddr3.txt
@@ -12,6 +12,9 @@ Required properties:

Optional properties:

+- manufacturer-id : <u32> Manufacturer ID value read from Mode Register 5
+- revision-id : <u32 u32> Revision IDs read from Mode Registers 6 and 7
+
The following optional properties represent the minimum value of some AC
timing parameters of the DDR device in terms of number of clock cycles.
These values shall be obtained from the device data-sheet.
@@ -49,6 +52,8 @@ samsung_K3QF2F20DB: lpddr3 {
compatible = "samsung,K3QF2F20DB", "jedec,lpddr3";
density = <16384>;
io-width = <32>;
+ manufacturer-id = <1>;
+ revision-id = <123 234>;
#address-cells = <1>;
#size-cells = <0>;

--
2.29.2

2021-03-27 17:39:22

by Rob Herring

Subject: Re: [PATCH] dt-bindings: ddr: Add optional manufacturer and revision ID to LPDDR3

On Tue, 23 Mar 2021 18:04:05 -0700, Julius Werner wrote:
> On some platforms, DDR parts are multi-sourced and the exact part number
> used is not know to either kernel or firmware at build time. Firmware
> can read identifying information from DDR mode registers at boot time
> but needs a way to communicate this information to kernel and/or
> userspace. This patch adds optional properties for this information to
> the existing "jedec,lpddr3" device tree binding to be used for that
> purpose.
>
> Signed-off-by: Julius Werner <[email protected]>
> ---
> Documentation/devicetree/bindings/ddr/lpddr3.txt | 5 +++++
> 1 file changed, 5 insertions(+)
>

Applied, thanks!