lkml.org 
[lkml]   [2019]   [Apr]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v6 04/10] Documentation: dt: device tree bindings for LPDDR3 memories
Date
The device tree bindings for LPDDR3 SDRAM memories.

For specifying the AC timing parameters of the memory device
the 'lpddr3' binding uses binding 'lpddr2-timings'.

Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
---
.../devicetree/bindings/lpddr3/lpddr3-timings.txt | 57 +++++++++++++
.../devicetree/bindings/lpddr3/lpddr3.txt | 93 ++++++++++++++++++++++
2 files changed, 150 insertions(+)
create mode 100644 Documentation/devicetree/bindings/lpddr3/lpddr3-timings.txt
create mode 100644 Documentation/devicetree/bindings/lpddr3/lpddr3.txt

diff --git a/Documentation/devicetree/bindings/lpddr3/lpddr3-timings.txt b/Documentation/devicetree/bindings/lpddr3/lpddr3-timings.txt
new file mode 100644
index 0000000..ebf3e00
--- /dev/null
+++ b/Documentation/devicetree/bindings/lpddr3/lpddr3-timings.txt
@@ -0,0 +1,57 @@
+* 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>
+- max-freq : 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@0 {
+ compatible = "jedec,lpddr3-timings";
+ min-freq = <100000000>;
+ max-freq = <800000000>;
+ 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/lpddr3/lpddr3.txt b/Documentation/devicetree/bindings/lpddr3/lpddr3.txt
new file mode 100644
index 0000000..fc7875c
--- /dev/null
+++ b/Documentation/devicetree/bindings/lpddr3/lpddr3.txt
@@ -0,0 +1,93 @@
+* LPDDR3 SDRAM memories compliant to JEDEC JESD209-2
+
+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
+
+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/lpddr3/lpddr3-timings.txt for more information on "lpddr3-timings"
+
+Example:
+
+samsung_K3QF2F20DB: lpddr3 {
+ compatible = "Samsung,K3QF2F20DB","jedec,lpddr3";
+ density = <16384>;
+ io-width = <32>;
+
+ 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@0 {
+ compatible = "jedec,lpddr3-timings";
+ min-freq = <100000000>;
+ max-freq = <800000000>;
+ 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>;
+ };
+}
--
2.7.4
\
 
 \ /
  Last update: 2019-04-19 21:39    [W:0.222 / U:0.116 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site