Add Renesas R-Car Gen4 E-FUSE support

The R-Car E-FUSE blocks can be modelled better using the nvmem framework.

Replace the R-Car V3U example by an R-Car S4-8 ES1.2 example, to show the definition of nvmem cells. While at it, drop unneeded labels from the examples, and fix indentation.

Add an entry to the MAINTAINERS file.

Reported-by Arnd Bergmann <[email protected]>

Signed-off-by Geert Uytterhoeven <[email protected]>

---
v3:
- New.

I would expect that the calib@144 node needs:

    #nvmem-cell-cells = <0>;

but after adding that, "make dt_binding_check" starts complaining:

Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: nvmem-layout: 'oneOf' conditional failed, one must be fixed:
'#address-cells', '#size-cells', 'calib@144' do not match any of the regexes: 'pinctrl-[0-9]+'
Unevaluated properties are not allowed ('nvmem-cell-cells' was unexpected)

'kontron,sl28-vpd' was expected
'onie,tlv-layout' was expected
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: nvmem-layout: Unevaluated properties are not allowed ('#address-cells', '#size-cells', 'calib@144' were unexpected)
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: Unevaluated properties are not allowed ('nvmem-layout' was unexpected)
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#

Quoted 19 lines · Geert Uytterhoeven

The R-Car E-FUSE blocks can be modelled better using the nvmem framework.

Replace the R-Car V3U example by an R-Car S4-8 ES1.2 example, to show the definition of nvmem cells. While at it, drop unneeded labels from the examples, and fix indentation.

Add an entry to the MAINTAINERS file.

Reported-by Arnd Bergmann <[email protected]>

Signed-off-by Geert Uytterhoeven <[email protected]>

---
v3:
- New.

I would expect that the calib@144 node needs:

    #nvmem-cell-cells = <0>;

Quoted 5 lines

but after adding that, "make dt_binding_check" starts complaining:

Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: nvmem-layout: 'oneOf' conditional failed, one must be fixed:
'#address-cells', '#size-cells', 'calib@144' do not match any of the regexes: 'pinctrl-[0-9]+'
Unevaluated properties are not allowed ('nvmem-cell-cells' was unexpected)

Did you want 'nvmem-cell-cells' or '#nvmem-cell-cells'?

Quoted 7 lines

'kontron,sl28-vpd' was expected
'onie,tlv-layout' was expected
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: nvmem-layout: Unevaluated properties are not allowed ('#address-cells', '#size-cells', 'calib@144' were unexpected)
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: Unevaluated properties are not allowed ('nvmem-layout' was unexpected)
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#

Hi Rob,

Quoted 20 lines · Rob Herring

Quoted 19 lines · Geert Uytterhoeven

The R-Car E-FUSE blocks can be modelled better using the nvmem framework.

Replace the R-Car V3U example by an R-Car S4-8 ES1.2 example, to show the definition of nvmem cells. While at it, drop unneeded labels from the examples, and fix indentation.

Add an entry to the MAINTAINERS file.

Reported-by Arnd Bergmann <[email protected]>

Signed-off-by Geert Uytterhoeven <[email protected]>

---
v3:
- New.

I would expect that the calib@144 node needs:

    #nvmem-cell-cells = <0>;

Quoted 7 lines

Quoted 5 lines

but after adding that, "make dt_binding_check" starts complaining:

Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: nvmem-layout: 'oneOf' conditional failed, one must be fixed:
'#address-cells', '#size-cells', 'calib@144' do not match any of the regexes: 'pinctrl-[0-9]+'
Unevaluated properties are not allowed ('nvmem-cell-cells' was unexpected)

Did you want 'nvmem-cell-cells' or '#nvmem-cell-cells'?

Oops, I've been (manually) re-adding and removing it again too many times during my investigations. "#nvmem-cell-cells", of course. According to my build logs, I had it right at least once ;-)

Quoted 7 lines

Quoted 7 lines

'kontron,sl28-vpd' was expected
'onie,tlv-layout' was expected
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: nvmem-layout: Unevaluated properties are not allowed ('#address-cells', '#size-cells', 'calib@144' were unexpected)
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: Unevaluated properties are not allowed ('nvmem-layout' was unexpected)
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#

Anyway, with or without the typo, the error message is about the same:

- Unevaluated properties are not allowed ('nvmem-cell-cells' was unexpected)
+ Unevaluated properties are not allowed ('#nvmem-cell-cells' was unexpected)

Quoted 43 lines · Geert Uytterhoeven

Quoted 20 lines · Rob Herring

Quoted 19 lines · Geert Uytterhoeven

The R-Car E-FUSE blocks can be modelled better using the nvmem framework.

Replace the R-Car V3U example by an R-Car S4-8 ES1.2 example, to show the definition of nvmem cells. While at it, drop unneeded labels from the examples, and fix indentation.

Add an entry to the MAINTAINERS file.

Reported-by Arnd Bergmann <[email protected]>

Signed-off-by Geert Uytterhoeven <[email protected]>

---
v3:
- New.

I would expect that the calib@144 node needs:

    #nvmem-cell-cells = <0>;

Quoted 7 lines

Quoted 5 lines

but after adding that, "make dt_binding_check" starts complaining:

Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: nvmem-layout: 'oneOf' conditional failed, one must be fixed:
'#address-cells', '#size-cells', 'calib@144' do not match any of the regexes: 'pinctrl-[0-9]+'
Unevaluated properties are not allowed ('nvmem-cell-cells' was unexpected)

Did you want 'nvmem-cell-cells' or '#nvmem-cell-cells'?

Oops, I've been (manually) re-adding and removing it again too many times during my investigations. "#nvmem-cell-cells", of course. According to my build logs, I had it right at least once ;-)

Quoted 7 lines

Quoted 7 lines

'kontron,sl28-vpd' was expected
'onie,tlv-layout' was expected
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: nvmem-layout: Unevaluated properties are not allowed ('#address-cells', '#size-cells', 'calib@144' were unexpected)
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: Unevaluated properties are not allowed ('nvmem-layout' was unexpected)
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#

Anyway, with or without the typo, the error message is about the same:

Quoted 2 lines

- Unevaluated properties are not allowed ('nvmem-cell-cells' was unexpected)
+ Unevaluated properties are not allowed ('#nvmem-cell-cells' was unexpected)

And if you test your schema or DTS with all nvmem (so also layouts) schemas?

Apparently fixed-layout schema was not applied.

Hi Krzysztof,

Quoted 21 lines · Krzysztof Kozlowski

Quoted 20 lines · Geert Uytterhoeven

Quoted 19 lines · Rob Herring

Quoted 18 lines · Geert Uytterhoeven

The R-Car E-FUSE blocks can be modelled better using the nvmem framework.

Replace the R-Car V3U example by an R-Car S4-8 ES1.2 example, to show the definition of nvmem cells. While at it, drop unneeded labels from the examples, and fix indentation.

Add an entry to the MAINTAINERS file.

Reported-by Arnd Bergmann <[email protected]>

Signed-off-by Geert Uytterhoeven <[email protected]>

---
v3:
- New.

I would expect that the calib@144 node needs:

    #nvmem-cell-cells = <0>;

Quoted 23 lines

Quoted 23 lines

Quoted 8 lines

Quoted 6 lines

but after adding that, "make dt_binding_check" starts complaining:

Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: nvmem-layout: 'oneOf' conditional failed, one must be fixed:
'#address-cells', '#size-cells', 'calib@144' do not match any of the regexes: 'pinctrl-[0-9]+'
Unevaluated properties are not allowed ('nvmem-cell-cells' was unexpected)

Did you want 'nvmem-cell-cells' or '#nvmem-cell-cells'?

Oops, I've been (manually) re-adding and removing it again too many times during my investigations. "#nvmem-cell-cells", of course. According to my build logs, I had it right at least once ;-)

Quoted 7 lines

Quoted 7 lines

'kontron,sl28-vpd' was expected
'onie,tlv-layout' was expected
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: nvmem-layout: Unevaluated properties are not allowed ('#address-cells', '#size-cells', 'calib@144' were unexpected)
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb: fuse@e6078800: Unevaluated properties are not allowed ('nvmem-layout' was unexpected)
from schema $id: http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#

Anyway, with or without the typo, the error message is about the same:

Quoted 7 lines

Quoted 2 lines

- Unevaluated properties are not allowed ('nvmem-cell-cells' was unexpected)
+ Unevaluated properties are not allowed ('#nvmem-cell-cells' was unexpected)

And if you test your schema or DTS with all nvmem (so also layouts) schemas?

Apparently fixed-layout schema was not applied.

With today's dt-schema:

Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb:
fuse@e6078800: nvmem-layout: 'oneOf' conditional failed, one must be fixed:

        '#address-cells', '#size-cells', 'calib@144' do not match any

of the regexes: 'pinctrl-[0-9]+'
Unevaluated properties are not allowed ('#nvmem-cell-cells'
was unexpected)
'kontron,sl28-vpd' was expected
'onie,tlv-layout' was expected
from schema $id:
http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb:
fuse@e6078800: nvmem-layout: Unevaluated properties are not allowed ('#address-cells', '#size-cells', 'calib@144' were unexpected)
from schema $id:
http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb:
fuse@e6078800: Unevaluated properties are not allowed ('nvmem-layout' was unexpected)
from schema $id:
http://devicetree.org/schemas/nvmem/renesas,rcar-efuse.yaml#
Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb:
nvmem-layout: calib@144: Unevaluated properties are not allowed ('#nvmem-cell-cells' was unexpected)
from schema $id:
http://devicetree.org/schemas/nvmem/layouts/fixed-layout.yaml#

According to the last line, fixed-layout.yaml is applied. Am I missing something?

Quoted 19 lines · Geert Uytterhoeven

Quoted 18 lines · Krzysztof Kozlowski

Quoted 17 lines · Geert Uytterhoeven

Quoted 16 lines · Rob Herring

Quoted 15 lines · Geert Uytterhoeven

The R-Car E-FUSE blocks can be modelled better using the nvmem framework.

Replace the R-Car V3U example by an R-Car S4-8 ES1.2 example, to show the definition of nvmem cells. While at it, drop unneeded labels from the examples, and fix indentation.

Add an entry to the MAINTAINERS file.

Reported-by Arnd Bergmann <[email protected]>

Signed-off-by Geert Uytterhoeven <[email protected]>

---
v3:
- New.

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

I would expect that the calib@144 node needs:

    #nvmem-cell-cells = <0>;

So this is for mac-base...

Quoted 1 line

Quoted 1 line

Quoted 1 line

Quoted 1 line

Quoted 1 line

but after adding that, "make dt_binding_check" starts complaining:

Quoted 6 lines

Quoted 4 lines

And if you test your schema or DTS with all nvmem (so also layouts) schemas?

Apparently fixed-layout schema was not applied.

With today's dt-schema:

Quoted 6 lines

Documentation/devicetree/bindings/nvmem/renesas,rcar-efuse.example.dtb:
nvmem-layout: calib@144: Unevaluated properties are not allowed ('#nvmem-cell-cells' was unexpected)
from schema $id:
http://devicetree.org/schemas/nvmem/layouts/fixed-layout.yaml#

Quoted 2 lines

According to the last line, fixed-layout.yaml is applied. Am I missing something?

I cannot reproduce it. Neither on 2024.6.dev5+g0e44e14b7eb4 nor on todays 2024.6.dev16+gc51125d571ca (which is actually from 15th of Aug).

But maybe we talk about modified patch, but then which exactly?

Hi Krzysztof,

Quoted 20 lines · Krzysztof Kozlowski

Quoted 19 lines · Geert Uytterhoeven

Quoted 18 lines · Krzysztof Kozlowski

Quoted 17 lines · Geert Uytterhoeven

Quoted 16 lines · Rob Herring

Quoted 15 lines · Geert Uytterhoeven

The R-Car E-FUSE blocks can be modelled better using the nvmem framework.

Replace the R-Car V3U example by an R-Car S4-8 ES1.2 example, to show the definition of nvmem cells. While at it, drop unneeded labels from the examples, and fix indentation.

Add an entry to the MAINTAINERS file.

Reported-by Arnd Bergmann <[email protected]>

Signed-off-by Geert Uytterhoeven <[email protected]>

---
v3:
- New.

Quoted 5 lines

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

I would expect that the calib@144 node needs:

    #nvmem-cell-cells = <0>;

So this is for mac-base...

No, mac-base is not involved.

Quoted 25 lines · Geert Uytterhoeven

Quoted 24 lines · Krzysztof Kozlowski

Quoted 22 lines · Geert Uytterhoeven

Quoted 21 lines · Krzysztof Kozlowski

Quoted 20 lines · Geert Uytterhoeven

Quoted 19 lines · Rob Herring

Quoted 18 lines · Geert Uytterhoeven

The R-Car E-FUSE blocks can be modelled better using the nvmem framework.

Replace the R-Car V3U example by an R-Car S4-8 ES1.2 example, to show the definition of nvmem cells. While at it, drop unneeded labels from the examples, and fix indentation.

Add an entry to the MAINTAINERS file.

Reported-by Arnd Bergmann <[email protected]>

Signed-off-by Geert Uytterhoeven <[email protected]>

---
v3:
- New.

I would expect that the calib@144 node needs:

    #nvmem-cell-cells = <0>;

Quoted 3 lines

Quoted 1 line

So this is for mac-base...

No, mac-base is not involved.

It is because that's the only case that allows #nvmem-cell-cells in fixed-cell.yaml. While fixed-cell.yaml allows additional properties, where it is referenced in fixed-layout.yaml does not.

Hi Rob,

Quoted 28 lines · Rob Herring

Quoted 27 lines · Geert Uytterhoeven

Quoted 25 lines · Krzysztof Kozlowski

Quoted 19 lines · Geert Uytterhoeven

Quoted 18 lines · Krzysztof Kozlowski

Quoted 17 lines · Geert Uytterhoeven

Quoted 16 lines · Rob Herring

Quoted 15 lines · Geert Uytterhoeven

The R-Car E-FUSE blocks can be modelled better using the nvmem framework.

Replace the R-Car V3U example by an R-Car S4-8 ES1.2 example, to show the definition of nvmem cells. While at it, drop unneeded labels from the examples, and fix indentation.

Add an entry to the MAINTAINERS file.

Reported-by Arnd Bergmann <[email protected]>

Signed-off-by Geert Uytterhoeven <[email protected]>

---
v3:
- New.

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

I would expect that the calib@144 node needs:

    #nvmem-cell-cells = <0>;

So this is for mac-base...

Quoted 5 lines

Quoted 1 line

No, mac-base is not involved.

It is because that's the only case that allows #nvmem-cell-cells in fixed-cell.yaml. While fixed-cell.yaml allows additional properties, where it is referenced in fixed-layout.yaml does not.

So all of this is normal, and you should just never use #nvmem-cell-cells, except in a node describing the location of the MAC address?

When no #nvmem-cell-cells property is present,
of_parse_phandle_with_optional_args() (as used in
of_nvmem_cell_get()) returns zero anyway

R-Car Gen3/Gen4 SoCs contain fuses indicating hardware support or hardware parameters. Unfortunately the various SoCs require different mechanisms to read the state of the fuses:
- On R-Car Gen3, the fuse monitor registers are in the middle of the Pin Function Controller (PFC) register block,
- On R-Car V3U and S4-8, the E-FUSE non-volatile memory is accessible through a separate register block in the PFC,
- On R-Car V4H and V4M, the E-FUSE non-volatile memory is accessible through the second register block of OTP_MEM.

As the first variant is quite different from the other two, and there is currently no use case requiring support for it, this patch series adds support for the last 2 variants only.

Note that the first two revisions of this series implemented only basic nvmem support, and a custom in-kernel API, mimicked after the fuse-tregra driver. Then, Arnd told me on IRC that the R-Car E-FUSE driver should use the nvmem framework fully.

The fuses' states can be read using the nvmem subsystem:
- In kernelspace, through the nvmem_cell_*() API.
A first known use case is reading tuning parameters for the Universal Flash Storage controller on R-Car S4-8 ES1.2.
- In userspace, through sysfs. E.g. on R-Car S4-8 ES1.2:

    / # hd /sys/bus/nvmem/devices/rcar-fuse/nvmem
    00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
    *
    000000e0  00 00 00 00 fe 00 00 00  00 00 00 00 00 00 00 00  |....�...........|
    000000f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
    *
    00000140  00 00 00 00 23 51 23 51  52 98 52 98 00 00 00 00  |....#Q#QR�R�....|
    00000150  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
    *
    00000200

Changes compared to v2[1]:
- Dropped accepted dt-bindings,
- Drop "pinctrl: renesas: Add R-Car Gen3 fuse support",
- New patch "dt-bindings: fuse: Move renesas,rcar-{efuse,otp} to

    nvmem",
  - Drop superfluous semicolon,
  - Drop the custom rcar_fuse_read() kernel API, in favor of the
    standard nvmem_cell_*() API,
  - Drop support for explicitly-instantiated platform devices with
    accompanying platform data, which would be needed to support fuses
    tightly integrated with the Pin Function Controller on R-Car Gen3
    SoCs.  It can be added when a use case shows up.
  - Move from drivers/soc/renesas/ to drivers/nvmem/,
  - Register the full register block that contains the E-FUSE data
    registers with the nvmem subsystem, but use keepouts to ignore all
    registers before the first or after the last documented data
    register.  Undocumented registers in between are still accessible.
  - Replace offset/nregs in rcar_fuse_data by start/end,
  - Use __ioread32_copy() helper,
  - Initialize most fields of struct nvmem_config in its declaration,
  - Rename nvmem device from "fuse" to "rcar-fuse",
  - Use NVMEM_DEVID_NONE,
  - Add an entry to the MAINTAINERS file,
  - Fix reg size,
  - New patch "arm64: dts: renesas: r8a779f4: Add UFS tuning parameters
    in E-FUSE".

Changes compared to v1[2]:
- Drop RFC state and broaden audience,
- Fix typo in one-line summary,
- Add Reviewed-by.

This has been tested on R-Car V3U, S4-8 ES1.0 and ES1.2, V4H, and V4M.

Thanks for your comments!

[1] https://lore.kernel.org/[email protected]
[2] https://lore.kernel.org/[email protected]

Geert Uytterhoeven (7):
dt-bindings: fuse: Move renesas,rcar-{efuse,otp} to nvmem
nvmem: Add R-Car E-FUSE driver
arm64: dts: renesas: r8a779a0: Add E-FUSE node
arm64: dts: renesas: r8a779f0: Add E-FUSE node
arm64: dts: renesas: r8a779f4: Add UFS tuning parameters in E-FUSE
arm64: dts: renesas: r8a779g0: Add OTP_MEM node
arm64: dts: renesas: r8a779h0: Add OTP_MEM node

 .../{fuse => nvmem}/renesas,rcar-efuse.yaml   |  35 +++--
 .../{fuse => nvmem}/renesas,rcar-otp.yaml     |  17 ++-
 MAINTAINERS                                   |   2 +
 arch/arm64/boot/dts/renesas/r8a779a0.dtsi     |   8 +
 arch/arm64/boot/dts/renesas/r8a779f0.dtsi     |   8 +
 arch/arm64/boot/dts/renesas/r8a779f4.dtsi     |  12 ++
 arch/arm64/boot/dts/renesas/r8a779g0.dtsi     |   5 +
 arch/arm64/boot/dts/renesas/r8a779h0.dtsi     |   5 +
 drivers/nvmem/Kconfig                         |  11 ++
 drivers/nvmem/Makefile                        |   2 +
 drivers/nvmem/rcar-efuse.c                    | 142 ++++++++++++++++++
 11 files changed, 230 insertions(+), 17 deletions(-)
 rename Documentation/devicetree/bindings/{fuse => nvmem}/renesas,rcar-efuse.yaml (54%)
 rename Documentation/devicetree/bindings/{fuse => nvmem}/renesas,rcar-otp.yaml (60%)
 create mode 100644 drivers/nvmem/rcar-efuse.c

--
2.34.1