xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/ddr/lpddr2.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun* LPDDR2 SDRAM memories compliant to JEDEC JESD209-2
2*4882a593Smuzhiyun
3*4882a593SmuzhiyunRequired properties:
4*4882a593Smuzhiyun- compatible : Should be one of - "jedec,lpddr2-nvm", "jedec,lpddr2-s2",
5*4882a593Smuzhiyun  "jedec,lpddr2-s4"
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun  "ti,jedec-lpddr2-s2" should be listed if the memory part is LPDDR2-S2 type
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun  "ti,jedec-lpddr2-s4" should be listed if the memory part is LPDDR2-S4 type
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun  "ti,jedec-lpddr2-nvm" should be listed if the memory part is LPDDR2-NVM type
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun- density  : <u32> representing density in Mb (Mega bits)
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun- io-width : <u32> representing bus width. Possible values are 8, 16, and 32
16*4882a593Smuzhiyun
17*4882a593SmuzhiyunOptional properties:
18*4882a593Smuzhiyun
19*4882a593SmuzhiyunThe following optional properties represent the minimum value of some AC
20*4882a593Smuzhiyuntiming parameters of the DDR device in terms of number of clock cycles.
21*4882a593SmuzhiyunThese values shall be obtained from the device data-sheet.
22*4882a593Smuzhiyun- tRRD-min-tck
23*4882a593Smuzhiyun- tWTR-min-tck
24*4882a593Smuzhiyun- tXP-min-tck
25*4882a593Smuzhiyun- tRTP-min-tck
26*4882a593Smuzhiyun- tCKE-min-tck
27*4882a593Smuzhiyun- tRPab-min-tck
28*4882a593Smuzhiyun- tRCD-min-tck
29*4882a593Smuzhiyun- tWR-min-tck
30*4882a593Smuzhiyun- tRASmin-min-tck
31*4882a593Smuzhiyun- tCKESR-min-tck
32*4882a593Smuzhiyun- tFAW-min-tck
33*4882a593Smuzhiyun
34*4882a593SmuzhiyunChild nodes:
35*4882a593Smuzhiyun- The lpddr2 node may have one or more child nodes of type "lpddr2-timings".
36*4882a593Smuzhiyun  "lpddr2-timings" provides AC timing parameters of the device for
37*4882a593Smuzhiyun  a given speed-bin. The user may provide the timings for as many
38*4882a593Smuzhiyun  speed-bins as is required. Please see Documentation/devicetree/
39*4882a593Smuzhiyun  bindings/ddr/lpddr2-timings.txt for more information on "lpddr2-timings"
40*4882a593Smuzhiyun
41*4882a593SmuzhiyunExample:
42*4882a593Smuzhiyun
43*4882a593Smuzhiyunelpida_ECB240ABACN : lpddr2 {
44*4882a593Smuzhiyun	compatible	= "Elpida,ECB240ABACN","jedec,lpddr2-s4";
45*4882a593Smuzhiyun	density		= <2048>;
46*4882a593Smuzhiyun	io-width	= <32>;
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun	tRPab-min-tck	= <3>;
49*4882a593Smuzhiyun	tRCD-min-tck	= <3>;
50*4882a593Smuzhiyun	tWR-min-tck	= <3>;
51*4882a593Smuzhiyun	tRASmin-min-tck	= <3>;
52*4882a593Smuzhiyun	tRRD-min-tck	= <2>;
53*4882a593Smuzhiyun	tWTR-min-tck	= <2>;
54*4882a593Smuzhiyun	tXP-min-tck	= <2>;
55*4882a593Smuzhiyun	tRTP-min-tck	= <2>;
56*4882a593Smuzhiyun	tCKE-min-tck	= <3>;
57*4882a593Smuzhiyun	tCKESR-min-tck	= <3>;
58*4882a593Smuzhiyun	tFAW-min-tck	= <8>;
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun	timings_elpida_ECB240ABACN_400mhz: lpddr2-timings@0 {
61*4882a593Smuzhiyun		compatible	= "jedec,lpddr2-timings";
62*4882a593Smuzhiyun		min-freq	= <10000000>;
63*4882a593Smuzhiyun		max-freq	= <400000000>;
64*4882a593Smuzhiyun		tRPab		= <21000>;
65*4882a593Smuzhiyun		tRCD		= <18000>;
66*4882a593Smuzhiyun		tWR		= <15000>;
67*4882a593Smuzhiyun		tRAS-min	= <42000>;
68*4882a593Smuzhiyun		tRRD		= <10000>;
69*4882a593Smuzhiyun		tWTR		= <7500>;
70*4882a593Smuzhiyun		tXP		= <7500>;
71*4882a593Smuzhiyun		tRTP		= <7500>;
72*4882a593Smuzhiyun		tCKESR		= <15000>;
73*4882a593Smuzhiyun		tDQSCK-max	= <5500>;
74*4882a593Smuzhiyun		tFAW		= <50000>;
75*4882a593Smuzhiyun		tZQCS		= <90000>;
76*4882a593Smuzhiyun		tZQCL		= <360000>;
77*4882a593Smuzhiyun		tZQinit		= <1000000>;
78*4882a593Smuzhiyun		tRAS-max-ns	= <70000>;
79*4882a593Smuzhiyun	};
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun	timings_elpida_ECB240ABACN_200mhz: lpddr2-timings@1 {
82*4882a593Smuzhiyun		compatible	= "jedec,lpddr2-timings";
83*4882a593Smuzhiyun		min-freq	= <10000000>;
84*4882a593Smuzhiyun		max-freq	= <200000000>;
85*4882a593Smuzhiyun		tRPab		= <21000>;
86*4882a593Smuzhiyun		tRCD		= <18000>;
87*4882a593Smuzhiyun		tWR		= <15000>;
88*4882a593Smuzhiyun		tRAS-min	= <42000>;
89*4882a593Smuzhiyun		tRRD		= <10000>;
90*4882a593Smuzhiyun		tWTR		= <10000>;
91*4882a593Smuzhiyun		tXP		= <7500>;
92*4882a593Smuzhiyun		tRTP		= <7500>;
93*4882a593Smuzhiyun		tCKESR		= <15000>;
94*4882a593Smuzhiyun		tDQSCK-max	= <5500>;
95*4882a593Smuzhiyun		tFAW		= <50000>;
96*4882a593Smuzhiyun		tZQCS		= <90000>;
97*4882a593Smuzhiyun		tZQCL		= <360000>;
98*4882a593Smuzhiyun		tZQinit		= <1000000>;
99*4882a593Smuzhiyun		tRAS-max-ns	= <70000>;
100*4882a593Smuzhiyun	};
101*4882a593Smuzhiyun
102*4882a593Smuzhiyun}
103