Re: [PATCH v2 0/3] Add control driver for ST M24LR RFID/NFC EEPROM chips

[Greg KH <gregkh@linuxfoundation.org>]

On Sun, Jun 01, 2025 at 03:30:18PM +0000, Abd-Alrhman Masalkhi wrote:
> This patch series adds support for the control interface of STMicroelectronics 
> M24LR RFID/NFC EEPROM devices, such as the M24LR04E-R. The chip exposes two 
> I2C addresses and two distinct address spaces: one for the system parameter 
> sector and another for the EEPROM memory. These address spaces overlap (both
> start at address 0). Due to this overlap, the chip cannot be represented by a
> single Device Tree node and handled by the standard at24 driver.
> 
> While it might be possible to model the system parameter sector and EEPROM
> as two separate DT nodes, each handled by the standard at24 driver, this
> leads to synchronization problems. For example, if a multi-page EEPROM write
> is in progress and a control command (e.g., a i2c write lock) is issued
> concurrently, it can result in incomplete or inconsistent writeing.
> 
> To overcome these issues, while maintaining a clean architecture and ensuring
> synchronization, the chip is managed by two drivers:
> 
> 1- The first driver exposes the system parameter sector and acts as an I2C mux
>    (gate) for EEPROM access. Using an I2C mux solves the synchronization issue.
>    This patch series implements this driver.
> 2- The second is the standard at24 driver, which handles the EEPROM.
> 
> Tested on: M24LR04E-R using Yocto on Raspberry Pi 4
> 
> Signed-off-by: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
> 
> Abd-Alrhman Masalkhi (3):
>   dt-bindings: eeprom: Add ST M24LR control interface
>   misc: add sysfs control driver for ST M24LR series RFID/NFC chips
>   ABI: sysfs: document control attributes for ST M24LR
> 
>  .../testing/sysfs-bus-i2c-devices-m24lr_ctl   |  96 +++
>  .../devicetree/bindings/eeprom/st,m24lr.yaml  |  72 ++
>  drivers/misc/Kconfig                          |  15 +
>  drivers/misc/Makefile                         |   1 +
>  drivers/misc/m24lr_ctl.c                      | 677 ++++++++++++++++++
>  5 files changed, 861 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-i2c-devices-m24lr_ctl
>  create mode 100644 Documentation/devicetree/bindings/eeprom/st,m24lr.yaml
>  create mode 100644 drivers/misc/m24lr_ctl.c
> 
> -- 
> 2.43.0
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
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created.  Hopefully you will not take offence and will fix the problem
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