xref: /linux/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml (revision 702648721db590b3425c31ade294000e18808345) 
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr2.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: LPDDR2 SDRAM compliant to JEDEC JESD209-2
8
9maintainers:
10  - Krzysztof Kozlowski <krzk@kernel.org>
11
12allOf:
13  - $ref: jedec,lpddr-props.yaml#
14
15properties:
16  compatible:
17    oneOf:
18      - items:
19          - enum:
20              - elpida,ECB240ABACN
21              - elpida,B8132B2PB-6D-F
22          - enum:
23              - jedec,lpddr2-nvm
24              - jedec,lpddr2-s2
25              - jedec,lpddr2-s4
26      - items:
27          - pattern: "^lpddr2-[0-9a-f]{2},[0-9a-f]{4}$"
28          - enum:
29              - jedec,lpddr2-nvm
30              - jedec,lpddr2-s2
31              - jedec,lpddr2-s4
32
33  revision-id1:
34    $ref: /schemas/types.yaml#/definitions/uint32
35    maximum: 255
36    description: |
37      Revision 1 value of SDRAM chip. Obtained from device datasheet.
38      Property is deprecated, use revision-id instead.
39    deprecated: true
40
41  revision-id2:
42    $ref: /schemas/types.yaml#/definitions/uint32
43    maximum: 255
44    description: |
45      Revision 2 value of SDRAM chip. Obtained from device datasheet.
46      Property is deprecated, use revision-id instead.
47    deprecated: true
48
49  tRRD-min-tck:
50    $ref: /schemas/types.yaml#/definitions/uint32
51    maximum: 16
52    description: |
53      Active bank a to active bank b in terms of number of clock cycles.
54      Obtained from device datasheet.
55
56  tWTR-min-tck:
57    $ref: /schemas/types.yaml#/definitions/uint32
58    maximum: 16
59    description: |
60      Internal WRITE-to-READ command delay in terms of number of clock cycles.
61      Obtained from device datasheet.
62
63  tXP-min-tck:
64    $ref: /schemas/types.yaml#/definitions/uint32
65    maximum: 16
66    description: |
67      Exit power-down to next valid command delay in terms of number of clock
68      cycles. Obtained from device datasheet.
69
70  tRTP-min-tck:
71    $ref: /schemas/types.yaml#/definitions/uint32
72    maximum: 16
73    description: |
74      Internal READ to PRECHARGE command delay in terms of number of clock
75      cycles. Obtained from device datasheet.
76
77  tCKE-min-tck:
78    $ref: /schemas/types.yaml#/definitions/uint32
79    maximum: 16
80    description: |
81      CKE minimum pulse width (HIGH and LOW pulse width) in terms of number
82      of clock cycles. Obtained from device datasheet.
83
84  tRPab-min-tck:
85    $ref: /schemas/types.yaml#/definitions/uint32
86    maximum: 16
87    description: |
88      Row precharge time (all banks) in terms of number of clock cycles.
89      Obtained from device datasheet.
90
91  tRCD-min-tck:
92    $ref: /schemas/types.yaml#/definitions/uint32
93    maximum: 16
94    description: |
95      RAS-to-CAS delay in terms of number of clock cycles. Obtained from
96      device datasheet.
97
98  tWR-min-tck:
99    $ref: /schemas/types.yaml#/definitions/uint32
100    maximum: 16
101    description: |
102      WRITE recovery time in terms of number of clock cycles. Obtained from
103      device datasheet.
104
105  tRASmin-min-tck:
106    $ref: /schemas/types.yaml#/definitions/uint32
107    maximum: 16
108    description: |
109      Row active time in terms of number of clock cycles. Obtained from device
110      datasheet.
111
112  tCKESR-min-tck:
113    $ref: /schemas/types.yaml#/definitions/uint32
114    maximum: 16
115    description: |
116      CKE minimum pulse width during SELF REFRESH (low pulse width during
117      SELF REFRESH) in terms of number of clock cycles. Obtained from device
118      datasheet.
119
120  tFAW-min-tck:
121    $ref: /schemas/types.yaml#/definitions/uint32
122    maximum: 16
123    description: |
124      Four-bank activate window in terms of number of clock cycles. Obtained
125      from device datasheet.
126
127patternProperties:
128  "^lpddr2-timings":
129    $ref: jedec,lpddr2-timings.yaml
130    description: |
131      The lpddr2 node may have one or more child nodes of type "lpddr2-timings".
132      "lpddr2-timings" provides AC timing parameters of the device for
133      a given speed-bin. The user may provide the timings for as many
134      speed-bins as is required.
135
136required:
137  - compatible
138  - density
139  - io-width
140
141unevaluatedProperties: false
142
143examples:
144  - |
145    elpida_ECB240ABACN: lpddr2 {
146        compatible = "elpida,ECB240ABACN", "jedec,lpddr2-s4";
147        density = <2048>;
148        io-width = <32>;
149        revision-id = <1 0>;
150
151        tRPab-min-tck = <3>;
152        tRCD-min-tck = <3>;
153        tWR-min-tck = <3>;
154        tRASmin-min-tck = <3>;
155        tRRD-min-tck = <2>;
156        tWTR-min-tck = <2>;
157        tXP-min-tck = <2>;
158        tRTP-min-tck = <2>;
159        tCKE-min-tck = <3>;
160        tCKESR-min-tck = <3>;
161        tFAW-min-tck = <8>;
162
163        timings_elpida_ECB240ABACN_400mhz: lpddr2-timings0 {
164            compatible = "jedec,lpddr2-timings";
165            min-freq = <10000000>;
166            max-freq = <400000000>;
167            tRPab = <21000>;
168            tRCD = <18000>;
169            tWR = <15000>;
170            tRAS-min = <42000>;
171            tRRD = <10000>;
172            tWTR = <7500>;
173            tXP = <7500>;
174            tRTP = <7500>;
175            tCKESR = <15000>;
176            tDQSCK-max = <5500>;
177            tFAW = <50000>;
178            tZQCS = <90000>;
179            tZQCL = <360000>;
180            tZQinit = <1000000>;
181            tRAS-max-ns = <70000>;
182        };
183
184        timings_elpida_ECB240ABACN_200mhz: lpddr2-timings1 {
185            compatible = "jedec,lpddr2-timings";
186            min-freq = <10000000>;
187            max-freq = <200000000>;
188            tRPab = <21000>;
189            tRCD = <18000>;
190            tWR = <15000>;
191            tRAS-min = <42000>;
192            tRRD = <10000>;
193            tWTR = <10000>;
194            tXP = <7500>;
195            tRTP = <7500>;
196            tCKESR = <15000>;
197            tDQSCK-max = <5500>;
198            tFAW = <50000>;
199            tZQCS = <90000>;
200            tZQCL = <360000>;
201            tZQinit = <1000000>;
202            tRAS-max-ns = <70000>;
203        };
204    };
205