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

[Rob Herring]

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 at suse.de>
> 
> ---
> 
> 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 at kernel.org>