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>
This patch allows a new kind of compatible string for LPDDR parts in the
device tree bindings, in addition to the existing hardcoded
<vendor>,<part-number> strings. The new format contains manufacturer and
part (revision) information in numerical form, such as lpddr3-ff,0201
for an LPDDR3 part with manufacturer ID ff and revision ID 0201. This
helps cases where LPDDR parts are probed at runtime by boot firmware and
cannot be matched to hardcoded part numbers, such as the firmware on the
qcom/sc7280-herobrine boards does (which supports 4 different memory
configurations at the moment, and more are expected to be added later at
a point where the boot firmware can no longer be updated to specifically
accommodate them).
Signed-off-by: Julius Werner <jwerner@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220930220606.303395-2-jwerner@chromium.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
The bindings for different LPDDR versions mostly use the same kinds of
properties, so in order to reduce duplication when we're adding support
for more versions, this patch creates a new lpddr-props subschema that
can be referenced by the others to define these common parts. (This will
consider a few smaller I/O width and density numbers "legal" for LPDDR3
that are usually not used there, but this should be harmless.)
Signed-off-by: Julius Werner <jwerner@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220930220606.303395-1-jwerner@chromium.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Commit 3539a2c6c6 ("dt-bindings: memory: lpddr2: Add revision-id
properties") added the properties `revision-id1` and `revision-id2` to
the "jedec,lpddr2" binding. The "jedec,lpddr3" binding already had a
single array property `revision-id` for the same purpose. For
consistency between related memory types, this patch deprecates the
LPDDR2 properties and instead adds a property in the same style as for
LPDDR3 to that binding.
Signed-off-by: Julius Werner <jwerner@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220224003421.3440124-2-jwerner@chromium.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
