Re: [PATCH v2 2/5] nvmem: Add driver to expose reserved memory as nvmem

From: Rob Herring
Date: Sun Jan 03 2021 - 11:18:11 EST


On Fri, 18 Dec 2020 16:43:17 +0100, Nicolas Saenz Julienne wrote:
> Firmware/co-processors might use reserved memory areas in order to pass
> data stemming from an nvmem device otherwise non accessible to Linux.
> For example an EEPROM memory only physically accessible to firmware, or
> data only accessible early at boot time.
>
> In order to expose this data to other drivers and user-space, the driver
> models the reserved memory area as an nvmem device.
>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
>
> ---
>
> Changes since v1:
> - Remove reserved memory phandle indirection by directly creating a
> platform device from the reserved memory DT node
> - Only map memory upon reading it to avoid corruption
> - Small cosmetic cleanups
>
> drivers/nvmem/Kconfig | 8 ++++
> drivers/nvmem/Makefile | 2 +
> drivers/nvmem/rmem.c | 97 ++++++++++++++++++++++++++++++++++++++++++
> drivers/of/platform.c | 1 +
> 4 files changed, 108 insertions(+)
> create mode 100644 drivers/nvmem/rmem.c
>

Reviewed-by: Rob Herring <robh@xxxxxxxxxx>