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| author | Aneesh V <aneesh@ti.com> | 2011-12-01 16:17:09 +0400 |
|---|---|---|
| committer | Benoit Cousson <b-cousson@ti.com> | 2012-09-07 21:18:37 +0400 |
| commit | 274c27b1f18060db6cc6bedad7812e5a7f97c6a4 (patch) | |
| tree | 6bacc3f04e6b37caa0c85ba711c0cea12340f559 /Documentation/devicetree/bindings/lpddr2/lpddr2-timings.txt | |
| parent | 399264b897bc0efb4fb5c026705805bec9ed93b8 (diff) | |
| download | linux-274c27b1f18060db6cc6bedad7812e5a7f97c6a4.tar.xz | |
Documentation: dt: device tree bindings for LPDDR2 memories
device tree bindings for LPDDR2 SDRAM memories compliant
to JESD209-2 standard.
The 'lpddr2' binding in-turn uses another binding 'lpddr2-timings'
for specifying the AC timing parameters of the memory device at
different speed-bins.
Reviewed-by: Benoit Cousson <b-cousson@ti.com>
Reviewed-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Aneesh V <aneesh@ti.com>
[santosh.shilimkar@ti.com: Rebased against 3.6-rc]
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Diffstat (limited to 'Documentation/devicetree/bindings/lpddr2/lpddr2-timings.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/lpddr2/lpddr2-timings.txt | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/lpddr2/lpddr2-timings.txt b/Documentation/devicetree/bindings/lpddr2/lpddr2-timings.txt new file mode 100644 index 000000000000..9ceb19e0c7fd --- /dev/null +++ b/Documentation/devicetree/bindings/lpddr2/lpddr2-timings.txt @@ -0,0 +1,52 @@ +* AC timing parameters of LPDDR2(JESD209-2) memories for a given speed-bin + +Required properties: +- compatible : Should be "jedec,lpddr2-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). Parameters with +a different unit have a suffix indicating the unit such as 'tRAS-max-ns' +- tRCD +- tWR +- tRAS-min +- tRRD +- tWTR +- tXP +- tRTP +- tDQSCK-max +- tFAW +- tZQCS +- tZQinit +- tRPab +- tZQCL +- tCKESR +- tRAS-max-ns +- tDQSCK-max-derated + +Example: + +timings_elpida_ECB240ABACN_400mhz: lpddr2-timings@0 { + compatible = "jedec,lpddr2-timings"; + min-freq = <10000000>; + max-freq = <400000000>; + tRPab = <21000>; + tRCD = <18000>; + tWR = <15000>; + tRAS-min = <42000>; + tRRD = <10000>; + tWTR = <7500>; + tXP = <7500>; + tRTP = <7500>; + tCKESR = <15000>; + tDQSCK-max = <5500>; + tFAW = <50000>; + tZQCS = <90000>; + tZQCL = <360000>; + tZQinit = <1000000>; + tRAS-max-ns = <70000>; +}; |