[PATCH v5 0/9] tegra20-emc: Identify memory chip by LPDDR configuration

[PATCH v5 0/9] tegra20-emc: Identify memory chip by LPDDR configuration

[Dmitry Osipenko]

Support memory chip identification by LPDDR2 configuration, which is
needed by ASUS Transformer TF101 tablet device that doesn't store RAMCODE
in Tegra's NVMEM.

Changelog:

v5: - Added new patch which adds vendor prefix for Elpida Inc.

    - Added new patch that updates existing device-tree to use proper
      lowercase "elpida," compatible prefix.

    - Changed Krzysztof's email address in the LPDDR2 binding.

    - Added uint32 types to the LPDDR2 binding, which was requested
      by Krzysztof Kozlowski.

v4: - Moved DDR bindings directory to memory-controllers/, like it
      was suggested by Krzysztof Kozlowski.

    - Converted existing LPDDR2 binding to schema and utilized it,
      like it was requested by Krzysztof Kozlowski.

    - Added Elpida B8132B2PB-6D-F compatible.

    - Made code changes that were requested by Krzysztof Kozlowski.

v3: - Corrected sub-node name in tegra20-emc.yaml.

v2: - Added separate binding for standard LPDDR2 properties, like it
      was suggested by Krzysztof Kozlowski.

    - Switched Tegra binding to use new lpddr2-configuration sub-node
      that contains the standard properties.

    - Extended commit message of the "emc: Document new LPDDR2 sub-node"
      patch, telling how the properties are supposed to be used, which
      was requested by Krzysztof Kozlowski.

    - Added new common helpers for parsing LPDDR2 properties and made
      tegra20-emc driver to use these helpers.

Dmitry Osipenko (9):
  dt-bindings: Relocate DDR bindings
  dt-bindings: memory: lpddr2: Convert to schema
  dt-bindings: memory: lpddr2: Add revision-id properties
  dt-bindings: memory: lpddr2: Document Elpida B8132B2PB-6D-F
  dt-bindings: Add vendor prefix for Elpida Memory
  ARM: dts: elpida_ecb240abacn: Change Elpida compatible
  dt-bindings: memory: tegra20: emc: Document new LPDDR2 sub-node
  memory: Add LPDDR2-info helpers
  memory: tegra20-emc: Support matching timings by LPDDR2 configuration

 .../devicetree/bindings/ddr/lpddr2.txt        | 102 --------
 .../memory-controllers/ddr/jedec,lpddr2.yaml  | 223 ++++++++++++++++++
 .../ddr/lpddr2-timings.txt                    |   0
 .../ddr/lpddr3-timings.txt                    |   0
 .../{ => memory-controllers}/ddr/lpddr3.txt   |   0
 .../nvidia,tegra20-emc.yaml                   |  23 +-
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 arch/arm/boot/dts/elpida_ecb240abacn.dtsi     |   2 +-
 drivers/memory/jedec_ddr.h                    |  47 ++++
 drivers/memory/jedec_ddr_data.c               |  41 ++++
 drivers/memory/of_memory.c                    |  87 +++++++
 drivers/memory/of_memory.h                    |   9 +
 drivers/memory/tegra/Kconfig                  |   1 +
 drivers/memory/tegra/tegra20-emc.c            | 199 ++++++++++++++--
 14 files changed, 617 insertions(+), 119 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/ddr/lpddr2.txt
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
 rename Documentation/devicetree/bindings/{ => memory-controllers}/ddr/lpddr2-timings.txt (100%)
 rename Documentation/devicetree/bindings/{ => memory-controllers}/ddr/lpddr3-timings.txt (100%)
 rename Documentation/devicetree/bindings/{ => memory-controllers}/ddr/lpddr3.txt (100%)

-- 
2.32.0

[PATCH v5 1/9] dt-bindings: Relocate DDR bindings

[Dmitry Osipenko]

Move DDR bindings to memory-controllers directory to make them more
discoverable.

Suggested-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../bindings/{ => memory-controllers}/ddr/lpddr2-timings.txt      | 0
 .../devicetree/bindings/{ => memory-controllers}/ddr/lpddr2.txt   | 0
 .../bindings/{ => memory-controllers}/ddr/lpddr3-timings.txt      | 0
 .../devicetree/bindings/{ => memory-controllers}/ddr/lpddr3.txt   | 0
 4 files changed, 0 insertions(+), 0 deletions(-)
 rename Documentation/devicetree/bindings/{ => memory-controllers}/ddr/lpddr2-timings.txt (100%)
 rename Documentation/devicetree/bindings/{ => memory-controllers}/ddr/lpddr2.txt (100%)
 rename Documentation/devicetree/bindings/{ => memory-controllers}/ddr/lpddr3-timings.txt (100%)
 rename Documentation/devicetree/bindings/{ => memory-controllers}/ddr/lpddr3.txt (100%)

diff --git a/Documentation/devicetree/bindings/ddr/lpddr2-timings.txt b/Documentation/devicetree/bindings/memory-controllers/ddr/lpddr2-timings.txt
similarity index 100%
rename from Documentation/devicetree/bindings/ddr/lpddr2-timings.txt
rename to Documentation/devicetree/bindings/memory-controllers/ddr/lpddr2-timings.txt
diff --git a/Documentation/devicetree/bindings/ddr/lpddr2.txt b/Documentation/devicetree/bindings/memory-controllers/ddr/lpddr2.txt
similarity index 100%
rename from Documentation/devicetree/bindings/ddr/lpddr2.txt
rename to Documentation/devicetree/bindings/memory-controllers/ddr/lpddr2.txt
diff --git a/Documentation/devicetree/bindings/ddr/lpddr3-timings.txt b/Documentation/devicetree/bindings/memory-controllers/ddr/lpddr3-timings.txt
similarity index 100%
rename from Documentation/devicetree/bindings/ddr/lpddr3-timings.txt
rename to Documentation/devicetree/bindings/memory-controllers/ddr/lpddr3-timings.txt
diff --git a/Documentation/devicetree/bindings/ddr/lpddr3.txt b/Documentation/devicetree/bindings/memory-controllers/ddr/lpddr3.txt
similarity index 100%
rename from Documentation/devicetree/bindings/ddr/lpddr3.txt
rename to Documentation/devicetree/bindings/memory-controllers/ddr/lpddr3.txt
-- 
2.32.0

Re: [PATCH v5 1/9] dt-bindings: Relocate DDR bindings

[Rob Herring]

On Thu, 07 Oct 2021 01:46:51 +0300, Dmitry Osipenko wrote:
> Move DDR bindings to memory-controllers directory to make them more
> discoverable.
> 
> Suggested-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../bindings/{ => memory-controllers}/ddr/lpddr2-timings.txt      | 0
>  .../devicetree/bindings/{ => memory-controllers}/ddr/lpddr2.txt   | 0
>  .../bindings/{ => memory-controllers}/ddr/lpddr3-timings.txt      | 0
>  .../devicetree/bindings/{ => memory-controllers}/ddr/lpddr3.txt   | 0
>  4 files changed, 0 insertions(+), 0 deletions(-)
>  rename Documentation/devicetree/bindings/{ => memory-controllers}/ddr/lpddr2-timings.txt (100%)
>  rename Documentation/devicetree/bindings/{ => memory-controllers}/ddr/lpddr2.txt (100%)
>  rename Documentation/devicetree/bindings/{ => memory-controllers}/ddr/lpddr3-timings.txt (100%)
>  rename Documentation/devicetree/bindings/{ => memory-controllers}/ddr/lpddr3.txt (100%)
> 

Acked-by: Rob Herring <robh@kernel.org>

[PATCH v5 2/9] dt-bindings: memory: lpddr2: Convert to schema

[Dmitry Osipenko]

Convert LPDDR2 binding to schema. I removed obsolete ti,jedec-lpddr2-*
compatibles since they were never used by device-trees and by the code.
I also changed "Elpida" compatible prefix to lowercase "elpida".

Suggested-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../memory-controllers/ddr/jedec,lpddr2.yaml  | 208 ++++++++++++++++++
 .../memory-controllers/ddr/lpddr2.txt         | 102 ---------
 2 files changed, 208 insertions(+), 102 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
 delete mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/lpddr2.txt

diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
new file mode 100644
index 000000000000..f931fe910ce5
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
@@ -0,0 +1,208 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr2.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: LPDDR2 SDRAM compliant to JEDEC JESD209-2
+
+maintainers:
+  - Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - elpida,ECB240ABACN
+          - enum:
+              - jedec,lpddr2-s4
+      - items:
+          - enum:
+              - jedec,lpddr2-s2
+      - items:
+          - enum:
+              - jedec,lpddr2-nvm
+
+  density:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Density in megabits of SDRAM chip. Obtained from device datasheet.
+    enum:
+      - 64
+      - 128
+      - 256
+      - 512
+      - 1024
+      - 2048
+      - 4096
+      - 8192
+      - 16384
+      - 32768
+
+  io-width:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      IO bus width in bits of SDRAM chip. Obtained from device datasheet.
+    enum:
+      - 32
+      - 16
+      - 8
+
+  tRRD-min-tck:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 16
+    description: |
+      Active bank a to active bank b in terms of number of clock cycles.
+      Obtained from device datasheet.
+
+  tWTR-min-tck:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 16
+    description: |
+      Internal WRITE-to-READ command delay in terms of number of clock cycles.
+      Obtained from device datasheet.
+
+  tXP-min-tck:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 16
+    description: |
+      Exit power-down to next valid command delay in terms of number of clock
+      cycles. Obtained from device datasheet.
+
+  tRTP-min-tck:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 16
+    description: |
+      Internal READ to PRECHARGE command delay in terms of number of clock
+      cycles. Obtained from device datasheet.
+
+  tCKE-min-tck:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 16
+    description: |
+      CKE minimum pulse width (HIGH and LOW pulse width) in terms of number
+      of clock cycles. Obtained from device datasheet.
+
+  tRPab-min-tck:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 16
+    description: |
+      Row precharge time (all banks) in terms of number of clock cycles.
+      Obtained from device datasheet.
+
+  tRCD-min-tck:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 16
+    description: |
+      RAS-to-CAS delay in terms of number of clock cycles. Obtained from
+      device datasheet.
+
+  tWR-min-tck:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 16
+    description: |
+      WRITE recovery time in terms of number of clock cycles. Obtained from
+      device datasheet.
+
+  tRASmin-min-tck:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 16
+    description: |
+      Row active time in terms of number of clock cycles. Obtained from device
+      datasheet.
+
+  tCKESR-min-tck:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 16
+    description: |
+      CKE minimum pulse width during SELF REFRESH (low pulse width during
+      SELF REFRESH) in terms of number of clock cycles. Obtained from device
+      datasheet.
+
+  tFAW-min-tck:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 16
+    description: |
+      Four-bank activate window in terms of number of clock cycles. Obtained
+      from device datasheet.
+
+patternProperties:
+  "^lpddr2-timings":
+    type: object
+    description: |
+      The lpddr2 node may have one or more child nodes of type "lpddr2-timings".
+      "lpddr2-timings" provides AC timing parameters of the device for
+      a given speed-bin. The user may provide the timings for as many
+      speed-bins as is required. Please see Documentation/devicetree/
+      bindings/memory-controllers/ddr/lpddr2-timings.txt for more information
+      on "lpddr2-timings".
+
+required:
+  - compatible
+  - density
+  - io-width
+
+additionalProperties: false
+
+examples:
+  - |
+    elpida_ECB240ABACN: lpddr2 {
+        compatible = "elpida,ECB240ABACN", "jedec,lpddr2-s4";
+        density = <2048>;
+        io-width = <32>;
+
+        tRPab-min-tck = <3>;
+        tRCD-min-tck = <3>;
+        tWR-min-tck = <3>;
+        tRASmin-min-tck = <3>;
+        tRRD-min-tck = <2>;
+        tWTR-min-tck = <2>;
+        tXP-min-tck = <2>;
+        tRTP-min-tck = <2>;
+        tCKE-min-tck = <3>;
+        tCKESR-min-tck = <3>;
+        tFAW-min-tck = <8>;
+
+        timings_elpida_ECB240ABACN_400mhz: lpddr2-timings0 {
+            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>;
+        };
+
+        timings_elpida_ECB240ABACN_200mhz: lpddr2-timings1 {
+            compatible = "jedec,lpddr2-timings";
+            min-freq = <10000000>;
+            max-freq = <200000000>;
+            tRPab = <21000>;
+            tRCD = <18000>;
+            tWR = <15000>;
+            tRAS-min = <42000>;
+            tRRD = <10000>;
+            tWTR = <10000>;
+            tXP = <7500>;
+            tRTP = <7500>;
+            tCKESR = <15000>;
+            tDQSCK-max = <5500>;
+            tFAW = <50000>;
+            tZQCS = <90000>;
+            tZQCL = <360000>;
+            tZQinit = <1000000>;
+            tRAS-max-ns = <70000>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/lpddr2.txt b/Documentation/devicetree/bindings/memory-controllers/ddr/lpddr2.txt
deleted file mode 100644
index ddd40121e6f6..000000000000
--- a/Documentation/devicetree/bindings/memory-controllers/ddr/lpddr2.txt
+++ /dev/null
@@ -1,102 +0,0 @@
-* LPDDR2 SDRAM memories compliant to JEDEC JESD209-2
-
-Required properties:
-- compatible : Should be one of - "jedec,lpddr2-nvm", "jedec,lpddr2-s2",
-  "jedec,lpddr2-s4"
-
-  "ti,jedec-lpddr2-s2" should be listed if the memory part is LPDDR2-S2 type
-
-  "ti,jedec-lpddr2-s4" should be listed if the memory part is LPDDR2-S4 type
-
-  "ti,jedec-lpddr2-nvm" should be listed if the memory part is LPDDR2-NVM type
-
-- density  : <u32> representing density in Mb (Mega bits)
-
-- io-width : <u32> representing bus width. Possible values are 8, 16, and 32
-
-Optional properties:
-
-The following optional properties represent the minimum value of some AC
-timing parameters of the DDR device in terms of number of clock cycles.
-These values shall be obtained from the device data-sheet.
-- tRRD-min-tck
-- tWTR-min-tck
-- tXP-min-tck
-- tRTP-min-tck
-- tCKE-min-tck
-- tRPab-min-tck
-- tRCD-min-tck
-- tWR-min-tck
-- tRASmin-min-tck
-- tCKESR-min-tck
-- tFAW-min-tck
-
-Child nodes:
-- The lpddr2 node may have one or more child nodes of type "lpddr2-timings".
-  "lpddr2-timings" provides AC timing parameters of the device for
-  a given speed-bin. The user may provide the timings for as many
-  speed-bins as is required. Please see Documentation/devicetree/
-  bindings/ddr/lpddr2-timings.txt for more information on "lpddr2-timings"
-
-Example:
-
-elpida_ECB240ABACN : lpddr2 {
-	compatible	= "Elpida,ECB240ABACN","jedec,lpddr2-s4";
-	density		= <2048>;
-	io-width	= <32>;
-
-	tRPab-min-tck	= <3>;
-	tRCD-min-tck	= <3>;
-	tWR-min-tck	= <3>;
-	tRASmin-min-tck	= <3>;
-	tRRD-min-tck	= <2>;
-	tWTR-min-tck	= <2>;
-	tXP-min-tck	= <2>;
-	tRTP-min-tck	= <2>;
-	tCKE-min-tck	= <3>;
-	tCKESR-min-tck	= <3>;
-	tFAW-min-tck	= <8>;
-
-	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>;
-	};
-
-	timings_elpida_ECB240ABACN_200mhz: lpddr2-timings@1 {
-		compatible	= "jedec,lpddr2-timings";
-		min-freq	= <10000000>;
-		max-freq	= <200000000>;
-		tRPab		= <21000>;
-		tRCD		= <18000>;
-		tWR		= <15000>;
-		tRAS-min	= <42000>;
-		tRRD		= <10000>;
-		tWTR		= <10000>;
-		tXP		= <7500>;
-		tRTP		= <7500>;
-		tCKESR		= <15000>;
-		tDQSCK-max	= <5500>;
-		tFAW		= <50000>;
-		tZQCS		= <90000>;
-		tZQCL		= <360000>;
-		tZQinit		= <1000000>;
-		tRAS-max-ns	= <70000>;
-	};
-
-}
-- 
2.32.0

Re: [PATCH v5 2/9] dt-bindings: memory: lpddr2: Convert to schema

[Rob Herring]

On Thu, 07 Oct 2021 01:46:52 +0300, Dmitry Osipenko wrote:
> Convert LPDDR2 binding to schema. I removed obsolete ti,jedec-lpddr2-*
> compatibles since they were never used by device-trees and by the code.
> I also changed "Elpida" compatible prefix to lowercase "elpida".
> 
> Suggested-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../memory-controllers/ddr/jedec,lpddr2.yaml  | 208 ++++++++++++++++++
>  .../memory-controllers/ddr/lpddr2.txt         | 102 ---------
>  2 files changed, 208 insertions(+), 102 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
>  delete mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/lpddr2.txt
> 

Reviewed-by: Rob Herring <robh@kernel.org>

[PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id properties

[Dmitry Osipenko]

Add optional revision-id standard LPDDR2 properties which will help to
identify memory chip.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../memory-controllers/ddr/jedec,lpddr2.yaml       | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
index f931fe910ce5..fe573750577e 100644
--- a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
@@ -24,6 +24,18 @@ properties:
           - enum:
               - jedec,lpddr2-nvm
 
+  revision-id1:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 255
+    description: |
+      Revision 1 value of SDRAM chip. Obtained from device datasheet.
+
+  revision-id2:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 255
+    description: |
+      Revision 2 value of SDRAM chip. Obtained from device datasheet.
+
   density:
     $ref: /schemas/types.yaml#/definitions/uint32
     description: |
@@ -151,6 +163,8 @@ examples:
         compatible = "elpida,ECB240ABACN", "jedec,lpddr2-s4";
         density = <2048>;
         io-width = <32>;
+        revision-id1 = <1>;
+        revision-id2 = <0>;
 
         tRPab-min-tck = <3>;
         tRCD-min-tck = <3>;
-- 
2.32.0

Re: [PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id properties

[Rob Herring]

On Thu, 07 Oct 2021 01:46:53 +0300, Dmitry Osipenko wrote:
> Add optional revision-id standard LPDDR2 properties which will help to
> identify memory chip.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../memory-controllers/ddr/jedec,lpddr2.yaml       | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id properties

[Julius Werner]

Apologies for only noticing this a couple of months too late... but
this patch added the same thing to the "jedec,lpddr2" bindings that
were previously added by
https://www.spinics.net/lists/devicetree/msg413733.html to
"jedec,lpddr3", but in a slightly incompatible manner. Should we
adjust it to make them consistent (two bytes in one property, rather
than a separate property for each)? Or is it too late to change that?

Re: [PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id properties

[Krzysztof Kozlowski]

On 08/02/2022 03:06, Julius Werner wrote:
> Apologies for only noticing this a couple of months too late... but
> this patch added the same thing to the "jedec,lpddr2" bindings that
> were previously added by
> https://www.spinics.net/lists/devicetree/msg413733.html to
> "jedec,lpddr3", but in a slightly incompatible manner. Should we
> adjust it to make them consistent (two bytes in one property, rather
> than a separate property for each)? Or is it too late to change that?

Unfortunately I have no clue what patch you talk about ("this patch").
There is no context here, no link except the older LPDDR3.

The latest discussion is about dtschema conversion, so no new fields are
being added:
https://lore.kernel.org/lkml/20220206135807.211767-1-krzysztof.kozlowski@canonical.com/

Feel free to propose something new on top of it.

Best regards,
Krzysztof

Re: [PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id properties

[Julius Werner]

> Unfortunately I have no clue what patch you talk about ("this patch").
> There is no context here, no link except the older LPDDR3.

Sorry, I tried to reply to
https://lore.kernel.org/all/20211006224659.21434-4-digetx@gmail.com/
([PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id
properties) and was hoping that would automatically provide context.
That patch added two one-cell properties `revision-id1` and
`revision-id2` to "jedec,lpddr2". Earlier in
https://www.spinics.net/lists/devicetree/msg413733.html ([PATCH]
dt-bindings: ddr: Add optional manufacturer and revision ID to
LPDDR3), I had added a single two-cell property `revision-id` for the
same purpose to "jedec,lpddr3".

I think it would be better if this was consistent between the two
types of LPDDR memory. Should I just send a patch that replaces the
two revision IDs in "jedec,lpddr2" with a single one according to the
principle of "jedec,lpddr3"? Or is it too late for that now and the
binding already considered stable and unchangeable?

Re: [PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id properties

[Krzysztof Kozlowski]

On 09/02/2022 00:46, Julius Werner wrote:
>> Unfortunately I have no clue what patch you talk about ("this patch").
>> There is no context here, no link except the older LPDDR3.
> 
> Sorry, I tried to reply to
> https://lore.kernel.org/all/20211006224659.21434-4-digetx@gmail.com/
> ([PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id
> properties) and was hoping that would automatically provide context.
> That patch added two one-cell properties `revision-id1` and
> `revision-id2` to "jedec,lpddr2". Earlier in
> https://www.spinics.net/lists/devicetree/msg413733.html ([PATCH]
> dt-bindings: ddr: Add optional manufacturer and revision ID to
> LPDDR3), I had added a single two-cell property `revision-id` for the
> same purpose to "jedec,lpddr3".
> 
> I think it would be better if this was consistent between the two
> types of LPDDR memory. Should I just send a patch that replaces the
> two revision IDs in "jedec,lpddr2" with a single one according to the
> principle of "jedec,lpddr3"? Or is it too late for that now and the
> binding already considered stable and unchangeable?

Hi Julius,

Having same bindings for revision ID makes sense. Sadly this was not
spotted during review, eh, life... Unfortunately the bindings are
already in a mainline release, so they are considered stable. You can
however bring patches (bindings + drivers/memory/of + dts) which make
the revision-id[12] deprecated and introduce new revision-id.

It should be something similar to what I did for max-freq:
https://lore.kernel.org/all/20220206135807.211767-7-krzysztof.kozlowski@canonical.com/

Dmitry,
Any early comments on such approach from you?

Best regards,
Krzysztof

Re: [PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id properties

[Dmitry Osipenko]

09.02.2022 11:58, Krzysztof Kozlowski пишет:
> On 09/02/2022 00:46, Julius Werner wrote:
>>> Unfortunately I have no clue what patch you talk about ("this patch").
>>> There is no context here, no link except the older LPDDR3.
>>
>> Sorry, I tried to reply to
>> https://lore.kernel.org/all/20211006224659.21434-4-digetx@gmail.com/
>> ([PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id
>> properties) and was hoping that would automatically provide context.
>> That patch added two one-cell properties `revision-id1` and
>> `revision-id2` to "jedec,lpddr2". Earlier in
>> https://www.spinics.net/lists/devicetree/msg413733.html ([PATCH]
>> dt-bindings: ddr: Add optional manufacturer and revision ID to
>> LPDDR3), I had added a single two-cell property `revision-id` for the
>> same purpose to "jedec,lpddr3".
>>
>> I think it would be better if this was consistent between the two
>> types of LPDDR memory. Should I just send a patch that replaces the
>> two revision IDs in "jedec,lpddr2" with a single one according to the
>> principle of "jedec,lpddr3"? Or is it too late for that now and the
>> binding already considered stable and unchangeable?
> 
> Hi Julius,
> 
> Having same bindings for revision ID makes sense. Sadly this was not
> spotted during review, eh, life... Unfortunately the bindings are
> already in a mainline release, so they are considered stable. You can
> however bring patches (bindings + drivers/memory/of + dts) which make
> the revision-id[12] deprecated and introduce new revision-id.
> 
> It should be something similar to what I did for max-freq:
> https://lore.kernel.org/all/20220206135807.211767-7-krzysztof.kozlowski@canonical.com/
> 
> Dmitry,
> Any early comments on such approach from you?

I don't mind, but I also don't see where the revision-id property of
LPDDR3 is used at all. I can't find any device-tree with LPDDR3
revision-id and don't see it being used in the code either. Maybe it's
the LPDDR3 binding that needs to be changed?
I made each LPDDR2 revision-id property to correspond to a dedicated MR
of LPDDR, which feels okay to me to since it matches h/w.

Re: [PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id properties

[Julius Werner]

> I don't mind, but I also don't see where the revision-id property of
> LPDDR3 is used at all. I can't find any device-tree with LPDDR3
> revision-id and don't see it being used in the code either. Maybe it's
> the LPDDR3 binding that needs to be changed?

We are using the revision ID in userspace (read through
/proc/device-tree) for runtime memory identification. We don't have a
kernel driver bound to it. Our boot firmware is inserting this value
at runtime into the FDT (that's basically the reason we have this, our
firmware auto-detects memory during boot and we use the FDT to report
what it found to userspace), that's why you can't find it anywhere in
the static device trees in boot/dts/.

> I made each LPDDR2 revision-id property to correspond to a dedicated MR
> of LPDDR, which feels okay to me to since it matches h/w.

I'm not super married to my solution, so if that makes things easier
we can standardize on the two-property version as well. I mostly
designed it my way because I thought we may one day also want to do
something like this for the 8-byte LPDDR5 serial-id, and then it would
get kinda cumbersome to have serial-id1 through serial-id8 all as
separate properties. But that's also a bridge we can cross when we get
there.

My use case is in a position where we could still change this now
without requiring backwards-compatibility. Krzysztof, would you be
okay if I instead changed the "jedec,lpddr3" to the same thing
"jedec,lpddr2" does -- seeing as the original patch was from me, my
use case could handle the switch, there has never been any actual
kernel code using the property, and it seems very unlikely that anyone
else has silently started using the same thing in the time it's been
in the tree? Or do we also need to go the official deprecation route
for that?

Re: [PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id properties

[Dmitry Osipenko]

В Wed, 9 Feb 2022 16:32:25 -0800
Julius Werner <jwerner@chromium.org> пишет:

> > I don't mind, but I also don't see where the revision-id property of
> > LPDDR3 is used at all. I can't find any device-tree with LPDDR3
> > revision-id and don't see it being used in the code either. Maybe
> > it's the LPDDR3 binding that needs to be changed?  
> 
> We are using the revision ID in userspace (read through
> /proc/device-tree) for runtime memory identification. We don't have a
> kernel driver bound to it. Our boot firmware is inserting this value
> at runtime into the FDT (that's basically the reason we have this, our
> firmware auto-detects memory during boot and we use the FDT to report
> what it found to userspace), that's why you can't find it anywhere in
> the static device trees in boot/dts/.

Thank you for the clarification. Which device is that and why userspace
needs to know so much about memory?

> > I made each LPDDR2 revision-id property to correspond to a
> > dedicated MR of LPDDR, which feels okay to me to since it matches
> > h/w.  
> 
> I'm not super married to my solution, so if that makes things easier
> we can standardize on the two-property version as well. I mostly
> designed it my way because I thought we may one day also want to do
> something like this for the 8-byte LPDDR5 serial-id, and then it would
> get kinda cumbersome to have serial-id1 through serial-id8 all as
> separate properties. But that's also a bridge we can cross when we get
> there.
> 
> My use case is in a position where we could still change this now
> without requiring backwards-compatibility. Krzysztof, would you be
> okay if I instead changed the "jedec,lpddr3" to the same thing
> "jedec,lpddr2" does -- seeing as the original patch was from me, my
> use case could handle the switch, there has never been any actual
> kernel code using the property, and it seems very unlikely that anyone
> else has silently started using the same thing in the time it's been
> in the tree? Or do we also need to go the official deprecation route
> for that?

If you're going to use multiple cells for other properties, then indeed
will be better to keep it consistent.

Re: [PATCH v5 3/9] dt-bindings: memory: lpddr2: Add revision-id properties

[Krzysztof Kozlowski]

On 11/02/2022 00:17, Dmitry Osipenko wrote:
> В Wed, 9 Feb 2022 16:32:25 -0800
> Julius Werner <jwerner@chromium.org> пишет:
> > 
>>> I made each LPDDR2 revision-id property to correspond to a
>>> dedicated MR of LPDDR, which feels okay to me to since it matches
>>> h/w.  
>>
>> I'm not super married to my solution, so if that makes things easier
>> we can standardize on the two-property version as well. I mostly
>> designed it my way because I thought we may one day also want to do
>> something like this for the 8-byte LPDDR5 serial-id, and then it would
>> get kinda cumbersome to have serial-id1 through serial-id8 all as
>> separate properties. But that's also a bridge we can cross when we get
>> there.
>>
>> My use case is in a position where we could still change this now
>> without requiring backwards-compatibility. Krzysztof, would you be
>> okay if I instead changed the "jedec,lpddr3" to the same thing
>> "jedec,lpddr2" does -- seeing as the original patch was from me, my
>> use case could handle the switch, there has never been any actual
>> kernel code using the property, and it seems very unlikely that anyone
>> else has silently started using the same thing in the time it's been
>> in the tree? Or do we also need to go the official deprecation route
>> for that?
> 
> If you're going to use multiple cells for other properties, then indeed
> will be better to keep it consistent.

Yeah, LPDDR5 is a nice argument. Let's go with the array approach (so
LPDDR3).

Julius,
Official deprecation is needed, because the property might be used also
in other projects or customers. But this is not a big deal - we will
just keep old property for some time.

Will you send a patch for it?

Best regards,
Krzysztof

[PATCH v5 4/9] dt-bindings: memory: lpddr2: Document Elpida B8132B2PB-6D-F

[Dmitry Osipenko]

Elpida B8132B2PB-6D-F memory chip is used by ASUS Transformer TF101
tablet, add compatible for it. We need to specify this compatible it
for a device-tree node containing corresponding memory timings in order
to allow software to match the timings with the detected hardware.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
index fe573750577e..25ed0266f6dd 100644
--- a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
@@ -15,6 +15,7 @@ properties:
       - items:
           - enum:
               - elpida,ECB240ABACN
+              - elpida,B8132B2PB-6D-F
           - enum:
               - jedec,lpddr2-s4
       - items:
-- 
2.32.0

Re: [PATCH v5 4/9] dt-bindings: memory: lpddr2: Document Elpida B8132B2PB-6D-F

[Rob Herring]

On Thu, 07 Oct 2021 01:46:54 +0300, Dmitry Osipenko wrote:
> Elpida B8132B2PB-6D-F memory chip is used by ASUS Transformer TF101
> tablet, add compatible for it. We need to specify this compatible it
> for a device-tree node containing corresponding memory timings in order
> to allow software to match the timings with the detected hardware.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml | 1 +
>  1 file changed, 1 insertion(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

[PATCH v5 5/9] dt-bindings: Add vendor prefix for Elpida Memory

[Dmitry Osipenko]

Elpida Memory designed, manufactured and sold dynamic random-access
memory (DRAM) products. It was acquired by Micron Technology in 2013,
still there are many devices with components from Elpida. Document the
vendor prefix.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index 1d77f151555b..8e06e3049a4f 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -355,6 +355,8 @@ patternProperties:
     description: Shenzhen Elida Technology Co., Ltd.
   "^elimo,.*":
     description: Elimo Engineering Ltd.
+  "^elpida,.*":
+    description: Elpida Memory, Inc.
   "^embest,.*":
     description: Shenzhen Embest Technology Co., Ltd.
   "^emlid,.*":
-- 
2.32.0

Re: [PATCH v5 5/9] dt-bindings: Add vendor prefix for Elpida Memory

[Rob Herring]

On Thu, 07 Oct 2021 01:46:55 +0300, Dmitry Osipenko wrote:
> Elpida Memory designed, manufactured and sold dynamic random-access
> memory (DRAM) products. It was acquired by Micron Technology in 2013,
> still there are many devices with components from Elpida. Document the
> vendor prefix.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

[PATCH v5 6/9] ARM: dts: elpida_ecb240abacn: Change Elpida compatible

[Dmitry Osipenko]

Vendor prefix shouldn't start with capital letter. The Elpida Memory
compatible was never used in practice, hence just correct the compatible.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 arch/arm/boot/dts/elpida_ecb240abacn.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/elpida_ecb240abacn.dtsi b/arch/arm/boot/dts/elpida_ecb240abacn.dtsi
index d87ee4794f83..9698801cbcfb 100644
--- a/arch/arm/boot/dts/elpida_ecb240abacn.dtsi
+++ b/arch/arm/boot/dts/elpida_ecb240abacn.dtsi
@@ -5,7 +5,7 @@
 
 / {
 	elpida_ECB240ABACN: lpddr2 {
-		compatible	= "Elpida,ECB240ABACN","jedec,lpddr2-s4";
+		compatible	= "elpida,ECB240ABACN","jedec,lpddr2-s4";
 		density		= <2048>;
 		io-width	= <32>;
 
-- 
2.32.0

[PATCH v5 7/9] dt-bindings: memory: tegra20: emc: Document new LPDDR2 sub-node

[Dmitry Osipenko]

Some Tegra20 boards don't have RAM code stored in NVMEM, which is used for
the memory chip identification and the identity information should be read
out from LPDDR2 chip in this case. Document new sub-node containing generic
LPDDR2 properties that will be used for the memory chip identification if
RAM code isn't available. The identification is done by reading out memory
configuration values from generic LPDDR2 mode registers of SDRAM chip and
comparing them with the values of device-tree 'lpddr2' sub-node.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../nvidia,tegra20-emc.yaml                   | 23 +++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.yaml b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.yaml
index cac6842dc8f1..2fa44951cfde 100644
--- a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.yaml
@@ -164,12 +164,20 @@ patternProperties:
       "#size-cells":
         const: 0
 
+      lpddr2:
+        $ref: "ddr/jedec,lpddr2.yaml#"
+        type: object
+
     patternProperties:
       "^emc-table@[0-9]+$":
         $ref: "#/$defs/emc-table"
 
-    required:
-      - nvidia,ram-code
+    oneOf:
+      - required:
+          - nvidia,ram-code
+
+      - required:
+          - lpddr2
 
     additionalProperties: false
 
@@ -227,4 +235,15 @@ examples:
                         0x00000000 0x00000000 0x00000000 0x00000000>;
             };
         };
+
+        emc-tables@1 {
+            reg = <1>;
+
+            lpddr2 {
+                compatible = "elpida,B8132B2PB-6D-F", "jedec,lpddr2-s4";
+                revision-id1 = <1>;
+                density = <2048>;
+                io-width = <16>;
+            };
+        };
     };
-- 
2.32.0

Re: [PATCH v5 7/9] dt-bindings: memory: tegra20: emc: Document new LPDDR2 sub-node

[Rob Herring]

On Thu, 07 Oct 2021 01:46:57 +0300, Dmitry Osipenko wrote:
> Some Tegra20 boards don't have RAM code stored in NVMEM, which is used for
> the memory chip identification and the identity information should be read
> out from LPDDR2 chip in this case. Document new sub-node containing generic
> LPDDR2 properties that will be used for the memory chip identification if
> RAM code isn't available. The identification is done by reading out memory
> configuration values from generic LPDDR2 mode registers of SDRAM chip and
> comparing them with the values of device-tree 'lpddr2' sub-node.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../nvidia,tegra20-emc.yaml                   | 23 +++++++++++++++++--
>  1 file changed, 21 insertions(+), 2 deletions(-)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

[PATCH v5 8/9] memory: Add LPDDR2-info helpers

[Dmitry Osipenko]

Add common helpers for reading and parsing standard LPDDR2 configuration
properties.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/jedec_ddr.h      | 47 ++++++++++++++++++
 drivers/memory/jedec_ddr_data.c | 41 ++++++++++++++++
 drivers/memory/of_memory.c      | 87 +++++++++++++++++++++++++++++++++
 drivers/memory/of_memory.h      |  9 ++++
 4 files changed, 184 insertions(+)

diff --git a/drivers/memory/jedec_ddr.h b/drivers/memory/jedec_ddr.h
index e59ccbd982d0..6cd508478b14 100644
--- a/drivers/memory/jedec_ddr.h
+++ b/drivers/memory/jedec_ddr.h
@@ -112,6 +112,26 @@
 #define NUM_DDR_ADDR_TABLE_ENTRIES			11
 #define NUM_DDR_TIMING_TABLE_ENTRIES			4
 
+#define LPDDR2_MANID_SAMSUNG				1
+#define LPDDR2_MANID_QIMONDA				2
+#define LPDDR2_MANID_ELPIDA				3
+#define LPDDR2_MANID_ETRON				4
+#define LPDDR2_MANID_NANYA				5
+#define LPDDR2_MANID_HYNIX				6
+#define LPDDR2_MANID_MOSEL				7
+#define LPDDR2_MANID_WINBOND				8
+#define LPDDR2_MANID_ESMT				9
+#define LPDDR2_MANID_SPANSION				11
+#define LPDDR2_MANID_SST				12
+#define LPDDR2_MANID_ZMOS				13
+#define LPDDR2_MANID_INTEL				14
+#define LPDDR2_MANID_NUMONYX				254
+#define LPDDR2_MANID_MICRON				255
+
+#define LPDDR2_TYPE_S4					0
+#define LPDDR2_TYPE_S2					1
+#define LPDDR2_TYPE_NVM					2
+
 /* Structure for DDR addressing info from the JEDEC spec */
 struct lpddr2_addressing {
 	u32 num_banks;
@@ -170,6 +190,33 @@ extern const struct lpddr2_timings
 	lpddr2_jedec_timings[NUM_DDR_TIMING_TABLE_ENTRIES];
 extern const struct lpddr2_min_tck lpddr2_jedec_min_tck;
 
+/* Structure of MR8 */
+union lpddr2_basic_config4 {
+	u32 value;
+
+	struct {
+		unsigned int arch_type : 2;
+		unsigned int density : 4;
+		unsigned int io_width : 2;
+	} __packed;
+};
+
+/*
+ * Structure for information about LPDDR2 chip. All parameters are
+ * matching raw values of standard mode register bitfields or set to
+ * -ENOENT if info unavailable.
+ */
+struct lpddr2_info {
+	int arch_type;
+	int density;
+	int io_width;
+	int manufacturer_id;
+	int revision_id1;
+	int revision_id2;
+};
+
+const char *lpddr2_jedec_manufacturer(unsigned int manufacturer_id);
+
 /*
  * Structure for timings for LPDDR3 based on LPDDR2 plus additional fields.
  * All parameters are in pico seconds(ps) excluding max_freq, min_freq which
diff --git a/drivers/memory/jedec_ddr_data.c b/drivers/memory/jedec_ddr_data.c
index ed601d813175..2cca4fa188f9 100644
--- a/drivers/memory/jedec_ddr_data.c
+++ b/drivers/memory/jedec_ddr_data.c
@@ -131,3 +131,44 @@ const struct lpddr2_min_tck lpddr2_jedec_min_tck = {
 	.tFAW		= 8
 };
 EXPORT_SYMBOL_GPL(lpddr2_jedec_min_tck);
+
+const char *lpddr2_jedec_manufacturer(unsigned int manufacturer_id)
+{
+	switch (manufacturer_id) {
+	case LPDDR2_MANID_SAMSUNG:
+		return "Samsung";
+	case LPDDR2_MANID_QIMONDA:
+		return "Qimonda";
+	case LPDDR2_MANID_ELPIDA:
+		return "Elpida";
+	case LPDDR2_MANID_ETRON:
+		return "Etron";
+	case LPDDR2_MANID_NANYA:
+		return "Nanya";
+	case LPDDR2_MANID_HYNIX:
+		return "Hynix";
+	case LPDDR2_MANID_MOSEL:
+		return "Mosel";
+	case LPDDR2_MANID_WINBOND:
+		return "Winbond";
+	case LPDDR2_MANID_ESMT:
+		return "ESMT";
+	case LPDDR2_MANID_SPANSION:
+		return "Spansion";
+	case LPDDR2_MANID_SST:
+		return "SST";
+	case LPDDR2_MANID_ZMOS:
+		return "ZMOS";
+	case LPDDR2_MANID_INTEL:
+		return "Intel";
+	case LPDDR2_MANID_NUMONYX:
+		return "Numonyx";
+	case LPDDR2_MANID_MICRON:
+		return "Micron";
+	default:
+		break;
+	}
+
+	return "invalid";
+}
+EXPORT_SYMBOL_GPL(lpddr2_jedec_manufacturer);
diff --git a/drivers/memory/of_memory.c b/drivers/memory/of_memory.c
index d9f5437d3bce..b94408954d85 100644
--- a/drivers/memory/of_memory.c
+++ b/drivers/memory/of_memory.c
@@ -298,3 +298,90 @@ const struct lpddr3_timings
 	return NULL;
 }
 EXPORT_SYMBOL(of_lpddr3_get_ddr_timings);
+
+/**
+ * of_lpddr2_get_info() - extracts information about the lpddr2 chip.
+ * @np: Pointer to device tree node containing lpddr2 info
+ * @dev: Device requesting info
+ *
+ * Populates lpddr2_info structure by extracting data from device
+ * tree node. Returns pointer to populated structure. If error
+ * happened while populating, returns NULL. If property is missing
+ * in a device-tree, then the corresponding value is set to -ENOENT.
+ */
+const struct lpddr2_info
+*of_lpddr2_get_info(struct device_node *np, struct device *dev)
+{
+	struct lpddr2_info *ret_info, info = {};
+	struct property *prop;
+	const char *cp;
+	int err;
+
+	err = of_property_read_u32(np, "revision-id1", &info.revision_id1);
+	if (err)
+		info.revision_id1 = -ENOENT;
+
+	err = of_property_read_u32(np, "revision-id2", &info.revision_id2);
+	if (err)
+		info.revision_id2 = -ENOENT;
+
+	err = of_property_read_u32(np, "io-width", &info.io_width);
+	if (err)
+		return NULL;
+
+	info.io_width = 32 / info.io_width - 1;
+
+	err = of_property_read_u32(np, "density", &info.density);
+	if (err)
+		return NULL;
+
+	info.density = ffs(info.density) - 7;
+
+	if (of_device_is_compatible(np, "jedec,lpddr2-s4"))
+		info.arch_type = LPDDR2_TYPE_S4;
+	else if (of_device_is_compatible(np, "jedec,lpddr2-s2"))
+		info.arch_type = LPDDR2_TYPE_S2;
+	else if (of_device_is_compatible(np, "jedec,lpddr2-nvm"))
+		info.arch_type = LPDDR2_TYPE_NVM;
+	else
+		return NULL;
+
+	prop = of_find_property(np, "compatible", NULL);
+	for (cp = of_prop_next_string(prop, NULL); cp;
+	     cp = of_prop_next_string(prop, cp)) {
+
+#define OF_LPDDR2_VENDOR_CMP(compat, ID) \
+		if (!of_compat_cmp(cp, compat ",", strlen(compat ","))) { \
+			info.manufacturer_id = LPDDR2_MANID_##ID; \
+			break; \
+		}
+
+		OF_LPDDR2_VENDOR_CMP("samsung", SAMSUNG)
+		OF_LPDDR2_VENDOR_CMP("qimonda", QIMONDA)
+		OF_LPDDR2_VENDOR_CMP("elpida", ELPIDA)
+		OF_LPDDR2_VENDOR_CMP("etron", ETRON)
+		OF_LPDDR2_VENDOR_CMP("nanya", NANYA)
+		OF_LPDDR2_VENDOR_CMP("hynix", HYNIX)
+		OF_LPDDR2_VENDOR_CMP("mosel", MOSEL)
+		OF_LPDDR2_VENDOR_CMP("winbond", WINBOND)
+		OF_LPDDR2_VENDOR_CMP("esmt", ESMT)
+		OF_LPDDR2_VENDOR_CMP("spansion", SPANSION)
+		OF_LPDDR2_VENDOR_CMP("sst", SST)
+		OF_LPDDR2_VENDOR_CMP("zmos", ZMOS)
+		OF_LPDDR2_VENDOR_CMP("intel", INTEL)
+		OF_LPDDR2_VENDOR_CMP("numonyx", NUMONYX)
+		OF_LPDDR2_VENDOR_CMP("micron", MICRON)
+
+#undef OF_LPDDR2_VENDOR_CMP
+	}
+
+	if (!info.manufacturer_id)
+		info.manufacturer_id = -ENOENT;
+
+	ret_info = devm_kzalloc(dev, sizeof(*ret_info), GFP_KERNEL);
+	if (ret_info)
+		*ret_info = info;
+
+	return ret_info;
+}
+EXPORT_SYMBOL(of_lpddr2_get_info);
diff --git a/drivers/memory/of_memory.h b/drivers/memory/of_memory.h
index 4a99b232ab0a..1c4e47fede8a 100644
--- a/drivers/memory/of_memory.h
+++ b/drivers/memory/of_memory.h
@@ -20,6 +20,9 @@ const struct lpddr3_min_tck *of_lpddr3_get_min_tck(struct device_node *np,
 const struct lpddr3_timings *
 of_lpddr3_get_ddr_timings(struct device_node *np_ddr,
 			  struct device *dev, u32 device_type, u32 *nr_frequencies);
+
+const struct lpddr2_info *of_lpddr2_get_info(struct device_node *np,
+					     struct device *dev);
 #else
 static inline const struct lpddr2_min_tck
 	*of_get_min_tck(struct device_node *np, struct device *dev)
@@ -46,6 +49,12 @@ static inline const struct lpddr3_timings
 {
 	return NULL;
 }
+
+static inline const struct lpddr2_info
+	*of_lpddr2_get_info(struct device_node *np, struct device *dev)
+{
+	return NULL;
+}
 #endif /* CONFIG_OF && CONFIG_DDR */
 
 #endif /* __LINUX_MEMORY_OF_REG_ */
-- 
2.32.0

[PATCH v5 9/9] memory: tegra20-emc: Support matching timings by LPDDR2 configuration

[Dmitry Osipenko]

ASUS Transformer TF101 doesn't provide RAM code and in this case memory
timings should be selected based on identity information read out from
SDRAM chip. Support matching timings by LPDDR2 configuration.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/Kconfig       |   1 +
 drivers/memory/tegra/tegra20-emc.c | 199 +++++++++++++++++++++++++++--
 2 files changed, 186 insertions(+), 14 deletions(-)

diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index f9bae36c03a3..7951764b4efe 100644
--- a/drivers/memory/tegra/Kconfig
+++ b/drivers/memory/tegra/Kconfig
@@ -16,6 +16,7 @@ config TEGRA20_EMC
 	depends on ARCH_TEGRA_2x_SOC || COMPILE_TEST
 	select DEVFREQ_GOV_SIMPLE_ONDEMAND
 	select PM_DEVFREQ
+	select DDR
 	help
 	  This driver is for the External Memory Controller (EMC) found on
 	  Tegra20 chips. The EMC controls the external DRAM on the board.
diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index c3462dbc8c22..77c5cd52d1a2 100644
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -5,6 +5,7 @@
  * Author: Dmitry Osipenko <digetx@gmail.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/clk/tegra.h>
 #include <linux/debugfs.h>
@@ -27,11 +28,15 @@
 #include <soc/tegra/common.h>
 #include <soc/tegra/fuse.h>
 
+#include "../jedec_ddr.h"
+#include "../of_memory.h"
+
 #include "mc.h"
 
 #define EMC_INTSTATUS				0x000
 #define EMC_INTMASK				0x004
 #define EMC_DBG					0x008
+#define EMC_ADR_CFG_0				0x010
 #define EMC_TIMING_CONTROL			0x028
 #define EMC_RC					0x02c
 #define EMC_RFC					0x030
@@ -68,6 +73,7 @@
 #define EMC_QUSE_EXTRA				0x0ac
 #define EMC_ODT_WRITE				0x0b0
 #define EMC_ODT_READ				0x0b4
+#define EMC_MRR					0x0ec
 #define EMC_FBIO_CFG5				0x104
 #define EMC_FBIO_CFG6				0x114
 #define EMC_STAT_CONTROL			0x160
@@ -94,6 +100,7 @@
 
 #define EMC_REFRESH_OVERFLOW_INT		BIT(3)
 #define EMC_CLKCHANGE_COMPLETE_INT		BIT(4)
+#define EMC_MRR_DIVLD_INT			BIT(5)
 
 #define EMC_DBG_READ_MUX_ASSEMBLY		BIT(0)
 #define EMC_DBG_WRITE_MUX_ACTIVE		BIT(1)
@@ -102,11 +109,25 @@
 #define EMC_DBG_CFG_PRIORITY			BIT(24)
 
 #define EMC_FBIO_CFG5_DRAM_WIDTH_X16		BIT(4)
+#define EMC_FBIO_CFG5_DRAM_TYPE			GENMASK(1, 0)
+
+#define EMC_MRR_DEV_SELECTN			GENMASK(31, 30)
+#define EMC_MRR_MRR_MA				GENMASK(23, 16)
+#define EMC_MRR_MRR_DATA			GENMASK(15, 0)
+
+#define EMC_ADR_CFG_0_EMEM_NUMDEV		GENMASK(25, 24)
 
 #define EMC_PWR_GATHER_CLEAR			(1 << 8)
 #define EMC_PWR_GATHER_DISABLE			(2 << 8)
 #define EMC_PWR_GATHER_ENABLE			(3 << 8)
 
+enum emc_dram_type {
+	DRAM_TYPE_RESERVED,
+	DRAM_TYPE_DDR1,
+	DRAM_TYPE_LPDDR2,
+	DRAM_TYPE_DDR2,
+};
+
 static const u16 emc_timing_registers[] = {
 	EMC_RC,
 	EMC_RFC,
@@ -201,6 +222,14 @@ struct tegra_emc {
 	struct mutex rate_lock;
 
 	struct devfreq_simple_ondemand_data ondemand_data;
+
+	/* memory chip identity information */
+	union lpddr2_basic_config4 basic_conf4;
+	unsigned int manufacturer_id;
+	unsigned int revision_id1;
+	unsigned int revision_id2;
+
+	bool mrr_error;
 };
 
 static irqreturn_t tegra_emc_isr(int irq, void *data)
@@ -397,15 +426,19 @@ static int tegra_emc_load_timings_from_dt(struct tegra_emc *emc,
 	if (!emc->timings)
 		return -ENOMEM;
 
-	emc->num_timings = child_count;
 	timing = emc->timings;
 
 	for_each_child_of_node(node, child) {
+		if (of_node_name_eq(child, "lpddr2"))
+			continue;
+
 		err = load_one_timing_from_dt(emc, timing++, child);
 		if (err) {
 			of_node_put(child);
 			return err;
 		}
+
+		emc->num_timings++;
 	}
 
 	sort(emc->timings, emc->num_timings, sizeof(*timing), cmp_timings,
@@ -422,12 +455,18 @@ static int tegra_emc_load_timings_from_dt(struct tegra_emc *emc,
 }
 
 static struct device_node *
-tegra_emc_find_node_by_ram_code(struct device *dev)
+tegra_emc_find_node_by_ram_code(struct tegra_emc *emc)
 {
+	struct device *dev = emc->dev;
 	struct device_node *np;
 	u32 value, ram_code;
 	int err;
 
+	if (emc->mrr_error) {
+		dev_warn(dev, "memory timings skipped due to MRR error\n");
+		return NULL;
+	}
+
 	if (of_get_child_count(dev->of_node) == 0) {
 		dev_info_once(dev, "device-tree doesn't have memory timings\n");
 		return NULL;
@@ -442,8 +481,49 @@ tegra_emc_find_node_by_ram_code(struct device *dev)
 	     np = of_find_node_by_name(np, "emc-tables")) {
 		err = of_property_read_u32(np, "nvidia,ram-code", &value);
 		if (err || value != ram_code) {
-			of_node_put(np);
-			continue;
+			struct device_node *lpddr2_np;
+			bool cfg_mismatches = false;
+
+			lpddr2_np = of_find_node_by_name(np, "lpddr2");
+			if (lpddr2_np) {
+				const struct lpddr2_info *info;
+
+				info = of_lpddr2_get_info(lpddr2_np, dev);
+				if (info) {
+					if (info->manufacturer_id >= 0 &&
+					    info->manufacturer_id != emc->manufacturer_id)
+						cfg_mismatches = true;
+
+					if (info->revision_id1 >= 0 &&
+					    info->revision_id1 != emc->revision_id1)
+						cfg_mismatches = true;
+
+					if (info->revision_id2 >= 0 &&
+					    info->revision_id2 != emc->revision_id2)
+						cfg_mismatches = true;
+
+					if (info->density != emc->basic_conf4.density)
+						cfg_mismatches = true;
+
+					if (info->io_width != emc->basic_conf4.io_width)
+						cfg_mismatches = true;
+
+					if (info->arch_type != emc->basic_conf4.arch_type)
+						cfg_mismatches = true;
+				} else {
+					dev_err(dev, "failed to parse %pOF\n", lpddr2_np);
+					cfg_mismatches = true;
+				}
+
+				of_node_put(lpddr2_np);
+			} else {
+				cfg_mismatches = true;
+			}
+
+			if (cfg_mismatches) {
+				of_node_put(np);
+				continue;
+			}
 		}
 
 		return np;
@@ -455,10 +535,72 @@ tegra_emc_find_node_by_ram_code(struct device *dev)
 	return NULL;
 }
 
+static int emc_read_lpddr_mode_register(struct tegra_emc *emc,
+					unsigned int emem_dev,
+					unsigned int register_addr,
+					unsigned int *register_data)
+{
+	u32 memory_dev = emem_dev + 1;
+	u32 val, mr_mask = 0xff;
+	int err;
+
+	/* clear data-valid interrupt status */
+	writel_relaxed(EMC_MRR_DIVLD_INT, emc->regs + EMC_INTSTATUS);
+
+	/* issue mode register read request */
+	val  = FIELD_PREP(EMC_MRR_DEV_SELECTN, memory_dev);
+	val |= FIELD_PREP(EMC_MRR_MRR_MA, register_addr);
+
+	writel_relaxed(val, emc->regs + EMC_MRR);
+
+	/* wait for the LPDDR2 data-valid interrupt */
+	err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_INTSTATUS, val,
+						val & EMC_MRR_DIVLD_INT,
+						1, 100);
+	if (err) {
+		dev_err(emc->dev, "mode register %u read failed: %d\n",
+			register_addr, err);
+		emc->mrr_error = true;
+		return err;
+	}
+
+	/* read out mode register data */
+	val = readl_relaxed(emc->regs + EMC_MRR);
+	*register_data = FIELD_GET(EMC_MRR_MRR_DATA, val) & mr_mask;
+
+	return 0;
+}
+
+static void emc_read_lpddr_sdram_info(struct tegra_emc *emc,
+				      unsigned int emem_dev,
+				      bool print_out)
+{
+	/* these registers are standard for all LPDDR JEDEC memory chips */
+	emc_read_lpddr_mode_register(emc, emem_dev, 5, &emc->manufacturer_id);
+	emc_read_lpddr_mode_register(emc, emem_dev, 6, &emc->revision_id1);
+	emc_read_lpddr_mode_register(emc, emem_dev, 7, &emc->revision_id2);
+	emc_read_lpddr_mode_register(emc, emem_dev, 8, &emc->basic_conf4.value);
+
+	if (!print_out)
+		return;
+
+	dev_info(emc->dev, "SDRAM[dev%u]: manufacturer: 0x%x (%s) rev1: 0x%x rev2: 0x%x prefetch: S%u density: %uMbit iowidth: %ubit\n",
+		 emem_dev, emc->manufacturer_id,
+		 lpddr2_jedec_manufacturer(emc->manufacturer_id),
+		 emc->revision_id1, emc->revision_id2,
+		 4 >> emc->basic_conf4.arch_type,
+		 64 << emc->basic_conf4.density,
+		 32 >> emc->basic_conf4.io_width);
+}
+
 static int emc_setup_hw(struct tegra_emc *emc)
 {
+	u32 emc_cfg, emc_dbg, emc_fbio, emc_adr_cfg;
 	u32 intmask = EMC_REFRESH_OVERFLOW_INT;
-	u32 emc_cfg, emc_dbg, emc_fbio;
+	static bool print_sdram_info_once;
+	enum emc_dram_type dram_type;
+	const char *dram_type_str;
+	unsigned int emem_numdev;
 
 	emc_cfg = readl_relaxed(emc->regs + EMC_CFG_2);
 
@@ -496,7 +638,36 @@ static int emc_setup_hw(struct tegra_emc *emc)
 	else
 		emc->dram_bus_width = 32;
 
-	dev_info_once(emc->dev, "%ubit DRAM bus\n", emc->dram_bus_width);
+	dram_type = FIELD_GET(EMC_FBIO_CFG5_DRAM_TYPE, emc_fbio);
+
+	switch (dram_type) {
+	case DRAM_TYPE_RESERVED:
+		dram_type_str = "INVALID";
+		break;
+	case DRAM_TYPE_DDR1:
+		dram_type_str = "DDR1";
+		break;
+	case DRAM_TYPE_LPDDR2:
+		dram_type_str = "LPDDR2";
+		break;
+	case DRAM_TYPE_DDR2:
+		dram_type_str = "DDR2";
+		break;
+	}
+
+	emc_adr_cfg = readl_relaxed(emc->regs + EMC_ADR_CFG_0);
+	emem_numdev = FIELD_GET(EMC_ADR_CFG_0_EMEM_NUMDEV, emc_adr_cfg) + 1;
+
+	dev_info_once(emc->dev, "%ubit DRAM bus, %u %s %s attached\n",
+		      emc->dram_bus_width, emem_numdev, dram_type_str,
+		      emem_numdev == 2 ? "devices" : "device");
+
+	if (dram_type == DRAM_TYPE_LPDDR2) {
+		while (emem_numdev--)
+			emc_read_lpddr_sdram_info(emc, emem_numdev,
+						  !print_sdram_info_once);
+		print_sdram_info_once = true;
+	}
 
 	return 0;
 }
@@ -1049,14 +1220,6 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	emc->clk_nb.notifier_call = tegra_emc_clk_change_notify;
 	emc->dev = &pdev->dev;
 
-	np = tegra_emc_find_node_by_ram_code(&pdev->dev);
-	if (np) {
-		err = tegra_emc_load_timings_from_dt(emc, np);
-		of_node_put(np);
-		if (err)
-			return err;
-	}
-
 	emc->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(emc->regs))
 		return PTR_ERR(emc->regs);
@@ -1065,6 +1228,14 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
+	np = tegra_emc_find_node_by_ram_code(emc);
+	if (np) {
+		err = tegra_emc_load_timings_from_dt(emc, np);
+		of_node_put(np);
+		if (err)
+			return err;
+	}
+
 	err = devm_request_irq(&pdev->dev, irq, tegra_emc_isr, 0,
 			       dev_name(&pdev->dev), emc);
 	if (err) {
-- 
2.32.0

Re: [PATCH v5 0/9] tegra20-emc: Identify memory chip by LPDDR configuration

[Krzysztof Kozlowski]

On Thu, 7 Oct 2021 01:46:50 +0300, Dmitry Osipenko wrote:
> Support memory chip identification by LPDDR2 configuration, which is
> needed by ASUS Transformer TF101 tablet device that doesn't store RAMCODE
> in Tegra's NVMEM.
> 
> Changelog:
> 
> v5: - Added new patch which adds vendor prefix for Elpida Inc.
> 
> [...]

Applied, thanks!

[1/9] dt-bindings: Relocate DDR bindings
      (no commit info)
[2/9] dt-bindings: memory: lpddr2: Convert to schema
      commit: 8a3294b74ac621ab03ef88cb964c13089ffdf015
[3/9] dt-bindings: memory: lpddr2: Add revision-id properties
      commit: 3c1a1b4b191978559cae5c626da012ef897c1139
[4/9] dt-bindings: memory: lpddr2: Document Elpida B8132B2PB-6D-F
      commit: 624f42157b99d253e6a52a7f93123eb0dbe1b26c
[5/9] dt-bindings: Add vendor prefix for Elpida Memory
      commit: 8712faaf12106bc70fcaef2cb89f7958faddbe59
[7/9] dt-bindings: memory: tegra20: emc: Document new LPDDR2 sub-node
      commit: ab4dd82cf5f8dd1943acf9243058262bc33c5af6
[8/9] memory: Add LPDDR2-info helpers
      commit: 5c767f684651e74f81c4d6a363e3779af3a77cc0
[9/9] memory: tegra20-emc: Support matching timings by LPDDR2 configuration
      commit: 4964b3e5c9ad4ad85b44f826a12c008af826545c


(dts patch not applied)

Best regards,
-- 
Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

Re: [PATCH v5 0/9] tegra20-emc: Identify memory chip by LPDDR configuration

[Dmitry Osipenko]

15.10.2021 10:20, Krzysztof Kozlowski пишет:
> On Thu, 7 Oct 2021 01:46:50 +0300, Dmitry Osipenko wrote:
>> Support memory chip identification by LPDDR2 configuration, which is
>> needed by ASUS Transformer TF101 tablet device that doesn't store RAMCODE
>> in Tegra's NVMEM.
>>
>> Changelog:
>>
>> v5: - Added new patch which adds vendor prefix for Elpida Inc.
>>
>> [...]
> 
> Applied, thanks!
> 
> [1/9] dt-bindings: Relocate DDR bindings
>       (no commit info)
> [2/9] dt-bindings: memory: lpddr2: Convert to schema
>       commit: 8a3294b74ac621ab03ef88cb964c13089ffdf015
> [3/9] dt-bindings: memory: lpddr2: Add revision-id properties
>       commit: 3c1a1b4b191978559cae5c626da012ef897c1139
> [4/9] dt-bindings: memory: lpddr2: Document Elpida B8132B2PB-6D-F
>       commit: 624f42157b99d253e6a52a7f93123eb0dbe1b26c
> [5/9] dt-bindings: Add vendor prefix for Elpida Memory
>       commit: 8712faaf12106bc70fcaef2cb89f7958faddbe59
> [7/9] dt-bindings: memory: tegra20: emc: Document new LPDDR2 sub-node
>       commit: ab4dd82cf5f8dd1943acf9243058262bc33c5af6
> [8/9] memory: Add LPDDR2-info helpers
>       commit: 5c767f684651e74f81c4d6a363e3779af3a77cc0
> [9/9] memory: tegra20-emc: Support matching timings by LPDDR2 configuration
>       commit: 4964b3e5c9ad4ad85b44f826a12c008af826545c
> 
> 
> (dts patch not applied)

I'll try to send that dts patch to OMAP people, thanks.