lkml.org 
[lkml]   [2019]   [Jul]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v12 2/9] dt-bindings: ddr: add LPDDR3 memories
Date
Specifies the AC timing parameters of the LPDDR3 memory device.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
---
.../bindings/ddr/lpddr3-timings.txt | 58 +++++++++++
.../devicetree/bindings/ddr/lpddr3.txt | 97 +++++++++++++++++++
2 files changed, 155 insertions(+)
create mode 100644 Documentation/devicetree/bindings/ddr/lpddr3-timings.txt
create mode 100644 Documentation/devicetree/bindings/ddr/lpddr3.txt

diff --git a/Documentation/devicetree/bindings/ddr/lpddr3-timings.txt b/Documentation/devicetree/bindings/ddr/lpddr3-timings.txt
new file mode 100644
index 000000000000..84705e50a3fd
--- /dev/null
+++ b/Documentation/devicetree/bindings/ddr/lpddr3-timings.txt
@@ -0,0 +1,58 @@
+* AC timing parameters of LPDDR3 memories for a given speed-bin.
+
+The structures are based on LPDDR2 and extended where needed.
+
+Required properties:
+- compatible : Should be "jedec,lpddr3-timings"
+- min-freq : minimum DDR clock frequency for the speed-bin. Type is <u32>
+- reg : maximum DDR clock frequency for the speed-bin. Type is <u32>
+
+Optional properties:
+
+The following properties represent AC timing parameters from the memory
+data-sheet of the device for a given speed-bin. All these properties are
+of type <u32> and the default unit is ps (pico seconds).
+- tRFC
+- tRRD
+- tRPab
+- tRPpb
+- tRCD
+- tRC
+- tRAS
+- tWTR
+- tWR
+- tRTP
+- tW2W-C2C
+- tR2R-C2C
+- tFAW
+- tXSR
+- tXP
+- tCKE
+- tCKESR
+- tMRD
+
+Example:
+
+timings_samsung_K3QF2F20DB_800mhz: lpddr3-timings@800000000 {
+ compatible = "jedec,lpddr3-timings";
+ reg = <800000000>; /* workaround: it shows max-freq */
+ min-freq = <100000000>;
+ tRFC = <65000>;
+ tRRD = <6000>;
+ tRPab = <12000>;
+ tRPpb = <12000>;
+ tRCD = <10000>;
+ tRC = <33750>;
+ tRAS = <23000>;
+ tWTR = <3750>;
+ tWR = <7500>;
+ tRTP = <3750>;
+ tW2W-C2C = <0>;
+ tR2R-C2C = <0>;
+ tFAW = <25000>;
+ tXSR = <70000>;
+ tXP = <3750>;
+ tCKE = <3750>;
+ tCKESR = <3750>;
+ tMRD = <7000>;
+};
diff --git a/Documentation/devicetree/bindings/ddr/lpddr3.txt b/Documentation/devicetree/bindings/ddr/lpddr3.txt
new file mode 100644
index 000000000000..3b2485b84b3f
--- /dev/null
+++ b/Documentation/devicetree/bindings/ddr/lpddr3.txt
@@ -0,0 +1,97 @@
+* LPDDR3 SDRAM memories compliant to JEDEC JESD209-3C
+
+Required properties:
+- compatible : Should be - "jedec,lpddr3"
+- density : <u32> representing density in Mb (Mega bits)
+- io-width : <u32> representing bus width. Possible values are 8, 16, 32, 64
+- #address-cells: Must be set to 1
+- #size-cells: Must be set to 0
+
+Optional properties:
+
+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.
+- tRFC-min-tck
+- tRRD-min-tck
+- tRPab-min-tck
+- tRPpb-min-tck
+- tRCD-min-tck
+- tRC-min-tck
+- tRAS-min-tck
+- tWTR-min-tck
+- tWR-min-tck
+- tRTP-min-tck
+- tW2W-C2C-min-tck
+- tR2R-C2C-min-tck
+- tWL-min-tck
+- tDQSCK-min-tck
+- tRL-min-tck
+- tFAW-min-tck
+- tXSR-min-tck
+- tXP-min-tck
+- tCKE-min-tck
+- tCKESR-min-tck
+- tMRD-min-tck
+
+Child nodes:
+- The lpddr3 node may have one or more child nodes of type "lpddr3-timings".
+ "lpddr3-timings" provides AC timing parameters of the device for
+ a given speed-bin. Please see Documentation/devicetree/
+ bindings/ddr/lpddr3-timings.txt for more information on "lpddr3-timings"
+
+Example:
+
+samsung_K3QF2F20DB: lpddr3 {
+ compatible = "Samsung,K3QF2F20DB", "jedec,lpddr3";
+ density = <16384>;
+ io-width = <32>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ tRFC-min-tck = <17>;
+ tRRD-min-tck = <2>;
+ tRPab-min-tck = <2>;
+ tRPpb-min-tck = <2>;
+ tRCD-min-tck = <3>;
+ tRC-min-tck = <6>;
+ tRAS-min-tck = <5>;
+ tWTR-min-tck = <2>;
+ tWR-min-tck = <7>;
+ tRTP-min-tck = <2>;
+ tW2W-C2C-min-tck = <0>;
+ tR2R-C2C-min-tck = <0>;
+ tWL-min-tck = <8>;
+ tDQSCK-min-tck = <5>;
+ tRL-min-tck = <14>;
+ tFAW-min-tck = <5>;
+ tXSR-min-tck = <12>;
+ tXP-min-tck = <2>;
+ tCKE-min-tck = <2>;
+ tCKESR-min-tck = <2>;
+ tMRD-min-tck = <5>;
+
+ timings_samsung_K3QF2F20DB_800mhz: lpddr3-timings@800000000 {
+ compatible = "jedec,lpddr3-timings";
+ reg = <800000000>; /* workaround: it shows max-freq */
+ min-freq = <100000000>;
+ tRFC = <65000>;
+ tRRD = <6000>;
+ tRPab = <12000>;
+ tRPpb = <12000>;
+ tRCD = <10000>;
+ tRC = <33750>;
+ tRAS = <23000>;
+ tWTR = <3750>;
+ tWR = <7500>;
+ tRTP = <3750>;
+ tW2W-C2C = <0>;
+ tR2R-C2C = <0>;
+ tFAW = <25000>;
+ tXSR = <70000>;
+ tXP = <3750>;
+ tCKE = <3750>;
+ tCKESR = <3750>;
+ tMRD = <7000>;
+ };
+}
--
2.17.1
\
 
 \ /
  Last update: 2019-07-22 11:49    [W:0.126 / U:45.312 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site