Files
linux-net/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr3.yaml
Clément Le Goffic dffaa1beea dt-bindings: memory: factorise LPDDR props into SDRAM props
LPDDR and DDR bindings are SDRAM types and are likely to share the same
properties (at least for density, io-width and reg).
To avoid bindings duplication, factorise the properties.

The compatible description has been updated because the MR (Mode
registers) used to get manufacturer ID and revision ID are not present
in case of DDR.
Those information should be in a SPD (Serial Presence Detect) EEPROM in
case of DIMM module or are known in case of soldered memory chips as
they are in the datasheet of the memory chips.

Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Clément Le Goffic <legoffic.clement@gmail.com>
Link: https://patch.msgid.link/20251118-b4-ddr-bindings-v9-1-a033ac5144da@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
2025-12-18 17:09:38 +01:00

244 lines
6.5 KiB
YAML

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr3.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: LPDDR3 SDRAM compliant to JEDEC JESD209-3
maintainers:
- Krzysztof Kozlowski <krzk@kernel.org>
allOf:
- $ref: jedec,sdram-props.yaml#
properties:
compatible:
oneOf:
- items:
- enum:
- samsung,K3QF2F20DB
- const: jedec,lpddr3
- items:
- pattern: "^lpddr3-[0-9a-f]{2},[0-9a-f]{4}$"
- const: jedec,lpddr3
'#address-cells':
const: 1
deprecated: true
manufacturer-id:
$ref: /schemas/types.yaml#/definitions/uint32
description: |
Manufacturer ID value read from Mode Register 5. The property is
deprecated, manufacturer should be derived from the compatible.
deprecated: true
'#size-cells':
const: 0
deprecated: true
tCKE-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
CKE minimum pulse width (HIGH and LOW pulse width) in terms of number
of clock cycles.
tCKESR-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
CKE minimum pulse width during SELF REFRESH (low pulse width during
SELF REFRESH) in terms of number of clock cycles.
tDQSCK-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
DQS output data access time from CK_t/CK_c in terms of number of clock
cycles.
tFAW-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 63
description: |
Four-bank activate window in terms of number of clock cycles.
tMRD-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
Mode register set command delay in terms of number of clock cycles.
tR2R-C2C-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
enum: [0, 1]
description: |
Additional READ-to-READ delay in chip-to-chip cases in terms of number
of clock cycles.
tRAS-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 63
description: |
Row active time in terms of number of clock cycles.
tRC-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 63
description: |
ACTIVATE-to-ACTIVATE command period in terms of number of clock cycles.
tRCD-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
RAS-to-CAS delay in terms of number of clock cycles.
tRFC-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 255
description: |
Refresh Cycle time in terms of number of clock cycles.
tRL-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
READ data latency in terms of number of clock cycles.
tRPab-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
Row precharge time (all banks) in terms of number of clock cycles.
tRPpb-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
Row precharge time (single banks) in terms of number of clock cycles.
tRRD-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
Active bank A to active bank B in terms of number of clock cycles.
tRTP-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
Internal READ to PRECHARGE command delay in terms of number of clock
cycles.
tW2W-C2C-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
enum: [0, 1]
description: |
Additional WRITE-to-WRITE delay in chip-to-chip cases in terms of number
of clock cycles.
tWL-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
WRITE data latency in terms of number of clock cycles.
tWR-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
WRITE recovery time in terms of number of clock cycles.
tWTR-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
description: |
Internal WRITE-to-READ command delay in terms of number of clock cycles.
tXP-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 255
description: |
Exit power-down to next valid command delay in terms of number of clock
cycles.
tXSR-min-tck:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 1023
description: |
SELF REFRESH exit to next valid command delay in terms of number of clock
cycles.
patternProperties:
"^timings((-[0-9])+|(@[0-9a-f]+))?$":
$ref: jedec,lpddr3-timings.yaml
description: |
The lpddr3 node may have one or more child nodes with timings.
Each timing node provides AC timing parameters of the device for a given
speed-bin. The user may provide the timings for as many speed-bins as is
required.
required:
- compatible
- density
- io-width
unevaluatedProperties: false
examples:
- |
lpddr3 {
compatible = "samsung,K3QF2F20DB", "jedec,lpddr3";
density = <16384>;
io-width = <32>;
tCKE-min-tck = <2>;
tCKESR-min-tck = <2>;
tDQSCK-min-tck = <5>;
tFAW-min-tck = <5>;
tMRD-min-tck = <5>;
tR2R-C2C-min-tck = <0>;
tRAS-min-tck = <5>;
tRC-min-tck = <6>;
tRCD-min-tck = <3>;
tRFC-min-tck = <17>;
tRL-min-tck = <14>;
tRPab-min-tck = <2>;
tRPpb-min-tck = <2>;
tRRD-min-tck = <2>;
tRTP-min-tck = <2>;
tW2W-C2C-min-tck = <0>;
tWL-min-tck = <8>;
tWR-min-tck = <7>;
tWTR-min-tck = <2>;
tXP-min-tck = <2>;
tXSR-min-tck = <12>;
timings {
compatible = "jedec,lpddr3-timings";
max-freq = <800000000>;
min-freq = <100000000>;
tCKE = <3750>;
tCKESR = <3750>;
tFAW = <25000>;
tMRD = <7000>;
tR2R-C2C = <0>;
tRAS = <23000>;
tRC = <33750>;
tRCD = <10000>;
tRFC = <65000>;
tRPab = <12000>;
tRPpb = <12000>;
tRRD = <6000>;
tRTP = <3750>;
tW2W-C2C = <0>;
tWR = <7500>;
tWTR = <3750>;
tXP = <3750>;
tXSR = <70000>;
};
};