Re: [PATCH v4 0/2] Make i.MX9 OCOTP work as accessing controller

[Peng Fan <peng.fan@oss.nxp.com>]

Hi Srinivas,

Is this patchset good for you to pick up?

Thanks,
Peng
On Mon, Dec 23, 2024 at 08:46:12AM +0800, Peng Fan (OSS) wrote:
>Previously there was discussion on using "feature-controller" or
>adding a specific node to group the fuse information for U-Boot to
>parse and update node. But rejected by DT maintainer(Rob).
>
>Since the STM32 engineers added access controller concept and landed
>the support in Linux Kernel, reuse the concept for i.MX.
>
>i.MX OCOTP eFuse has some bits to indicate a specific periphral or
>function is avaiable for current chip, for example i.MX93 has variants
>that not have NPU. So introduce '#access-controller-cells' for OCOTP,
>and add "#access-controllers = <&ocotp [gate_index]>" for periphrals
>that needs accessing control checking.
>
>In OCOTP driver, the nodes under "/" will be iterated, and checked
>if property "#access-controllers" exsits. If not allow access, detach
>the node.
>
>In the end, cpu nodes should still be handled by bootloader.
>And I may also update i.MX8M to use same method to support variants
>if this patchset is good.
>
>Signed-off-by: Peng Fan <peng.fan@nxp.com>
>---
>Changes in v4:
>- Add missing of_node_put(provider)
>- Typo fix in commit log
>- Link to v3: https://lore.kernel.org/r/20241219-imx-ocotp-v3-0-b22371098071@nxp.com
>
>Changes in v3:
>- Add A-b for patch 1
>- Use scoped API when iterate nodes and address build warning in patch 2
>- I am also thinking that to drop patch 2 to let
> bootloader to iterate the nodes that have access-controllers property and
> update the nodes before booting the kernel. Then just need patch 1 for
> the binding updates. Anyway, comments are welcomed.
>- Link to v2: https://lore.kernel.org/r/20241217-imx-ocotp-v2-0-3faa6cbff41b@nxp.com
>
>Changes in v2:
>- Add R-b for patch 1
>- Use '/' root node instead of '/soc' or '/soc@0' for patch 2
>- Link to v1: https://lore.kernel.org/r/20241212-imx-ocotp-v1-0-198bb0af86a0@nxp.com
>
>---
>Peng Fan (2):
>      dt-bindings: nvmem: imx-ocotp: Introduce #access-controller-cells
>      nvmem: imx-ocotp-ele: Support accessing controller for i.MX9
>
> .../devicetree/bindings/nvmem/imx-ocotp.yaml       |   5 +
> drivers/nvmem/imx-ocotp-ele.c                      | 184 ++++++++++++++++++++-
> include/dt-bindings/nvmem/fsl,imx93-ocotp.h        |  24 +++
> include/dt-bindings/nvmem/fsl,imx95-ocotp.h        |  43 +++++
> 4 files changed, 255 insertions(+), 1 deletion(-)
>---
>base-commit: 6d13015b67d58ddba56631c56e0a6f376ade0867
>change-id: 20241212-imx-ocotp-cbef304140f5
>
>Best regards,
>-- 
>Peng Fan <peng.fan@nxp.com>
>