Hi all,
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.
This patch series adds support for all 3 variants. It provides an
in-kernel API to read the fuses' states, as well as userspace access
through the nvmem subsystem and sysfs:
- R-Car Gen3: /sys/bus/platform/devices/rcar_fuse/fuse/nvmem
- R-Car V3U/S4: /sys/bus/platform/devices/e6078800.fuse/fuse/nvmem
- R-Car V4H/V4M: /sys/bus/platform/devices/e61be000.otp/fuse/nvmem
This has been tested on R-Car H3 ES2.0, M3-W and M3-W+, M3-N, V3M, V3H
and V3H2, D3, E3, V3U, S4-8 ES1.0 and ES1.2, V4H, and V4M.
For SoCs where E-FUSE is accessed through the PFC, it is not clear from
the documentation if any PFC module clock needs to be enabled for fuse
access. According to experiments on R-Car S4-8, the module clock and
reset only impact the GPIO functionality of the PFC, not the pinmux or
fuse monitor functionalities. So perhaps the clock/power-domains/resets
properties should be dropped from the DT bindings and DTS, as well as
the Runtime PM handling from the driver?
Changes compared to v1[1]:
- Drop RFC state and broaden audience,
- Fix typo in one-line summary,
- Add Reviewed-by.
Thanks for your comments!
[1] https://lore.kernel.org/r/cover.1714642390.git.geert+renesas@xxxxxxxxx
Geert Uytterhoeven (8):
dt-bindings: fuse: Document R-Car E-FUSE / PFC
dt-bindings: fuse: Document R-Car E-FUSE / OTP_MEM
soc: renesas: Add R-Car fuse driver
pinctrl: renesas: Add R-Car Gen3 fuse support
arm64: dts: renesas: r8a779a0: Add E-FUSE node
arm64: dts: renesas: r8a779f0: Add E-FUSE node
arm64: dts: renesas: r8a779g0: Add OTP_MEM node
arm64: dts: renesas: r8a779h0: Add OTP_MEM node
.../bindings/fuse/renesas,rcar-efuse.yaml | 55 +++++
.../bindings/fuse/renesas,rcar-otp.yaml | 38 ++++
arch/arm64/boot/dts/renesas/r8a779a0.dtsi | 8 +
arch/arm64/boot/dts/renesas/r8a779f0.dtsi | 8 +
arch/arm64/boot/dts/renesas/r8a779g0.dtsi | 5 +
arch/arm64/boot/dts/renesas/r8a779h0.dtsi | 5 +
drivers/pinctrl/renesas/core.c | 18 ++
drivers/pinctrl/renesas/pfc-r8a77951.c | 2 +
drivers/pinctrl/renesas/pfc-r8a7796.c | 4 +
drivers/pinctrl/renesas/pfc-r8a77965.c | 2 +
drivers/pinctrl/renesas/pfc-r8a77970.c | 2 +
drivers/pinctrl/renesas/pfc-r8a77980.c | 14 +-
drivers/pinctrl/renesas/pfc-r8a77990.c | 2 +
drivers/pinctrl/renesas/pfc-r8a77995.c | 2 +
drivers/pinctrl/renesas/sh_pfc.h | 4 +-
drivers/soc/renesas/Kconfig | 8 +
drivers/soc/renesas/Makefile | 1 +
drivers/soc/renesas/rcar-fuse.c | 201 ++++++++++++++++++
include/linux/platform_data/rcar_fuse.h | 11 +
include/linux/soc/renesas/rcar-fuse.h | 41 ++++
20 files changed, 429 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/fuse/renesas,rcar-efuse.yaml
create mode 100644 Documentation/devicetree/bindings/fuse/renesas,rcar-otp.yaml
create mode 100644 drivers/soc/renesas/rcar-fuse.c
create mode 100644 include/linux/platform_data/rcar_fuse.h
create mode 100644 include/linux/soc/renesas/rcar-fuse.h
--
2.34.1
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
