Introduce JEDEC compliant DDR bindings, that use new memory-props binding.
The DDR4 compatible can be made of explicit vendor names and part
numbers or be of the form "ddrX-YYYY,AAAA...-ZZ" when associated with an
SPD, where (according to JEDEC SPD4.1.2.L-6):
- YYYY is the manufacturer ID
- AAAA... is the part number
- ZZ is the revision ID
The former form is useful when the SDRAM vendor and part number are
known, for example, when memory is soldered on the board.
The latter form is useful when SDRAM nodes are created at runtime by
boot firmware that doesn't have access to static part number information.
Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Signed-off-by: Clément Le Goffic <legoffic.clement@gmail.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20251118-b4-ddr-bindings-v9-2-a033ac5144da@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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 adds a new device tree binding for an LPDDR channel to serve
as a top-level organizing node for LPDDR part nodes nested below it. An
LPDDR channel needs to have an "io-width" property to describe its width
(this is important because this width does not always match the io-width
of the part number, indicating that multiple parts are wired in parallel
on the same channel), as well as one or more nested "rank@X" nodes.
Those represent information about the individual ranks of each LPDDR
part connected on that channel and should match the existing
"jedec,lpddrX" bindings for individual LPDDR parts.
New platforms should be using this node -- the existing practice of
providing a raw, toplevel "jedec,lpddrX" node without indication of how
many identical parts are in the system should be considered deprecated.
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220930220606.303395-4-jwerner@chromium.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.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>
The timings node maximum frequency was passed as an unit address, which
is actually a workaround. Such workaround and unit address are not
needed at all, because the device memory node (parent) can contain
multiple timing nodes without unit addresses but with suffix used for
nodenames, e.g. timings-1.
LPDDR2 bindings already use such version, so unify the LPDDR3 with them.
Suggested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220206135807.211767-7-krzysztof.kozlowski@canonical.com
