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Date: Fri, 22 Mar 2024 10:52:17 -0700
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Subject: Re: [PATCH 0/8] block: implement NVMEM provider
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To: Daniel Golle <daniel@makrotopia.org>, Rob Herring <robh@kernel.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
 Conor Dooley <conor+dt@kernel.org>, Ulf Hansson <ulf.hansson@linaro.org>,
 Jens Axboe <axboe@kernel.dk>, Dave Chinner <dchinner@redhat.com>,
 Jan Kara <jack@suse.cz>, =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?=
 <linux@weissschuh.net>, Damien Le Moal <dlemoal@kernel.org>,
 Li Lingfeng <lilingfeng3@huawei.com>, Christian Brauner
 <brauner@kernel.org>, Christian Heusel <christian@heusel.eu>,
 Min Li <min15.li@samsung.com>, Adrian Hunter <adrian.hunter@intel.com>,
 Avri Altman <avri.altman@wdc.com>, Hannes Reinecke <hare@suse.de>,
 Christian Loehle <CLoehle@hyperstone.com>, Bean Huo <beanhuo@micron.com>,
 Yeqi Fu <asuk4.q@gmail.com>, Victor Shih <victor.shih@genesyslogic.com.tw>,
 Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
 Dominique Martinet <dominique.martinet@atmark-techno.com>,
 "Ricardo B. Marliere" <ricardo@marliere.net>, devicetree@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org,
 linux-block@vger.kernel.org
References: <cover.1711048433.git.daniel@makrotopia.org>
From: Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <cover.1711048433.git.daniel@makrotopia.org>
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On 3/21/24 12:31, Daniel Golle wrote:
> On embedded devices using an eMMC it is common that one or more (hw/sw)
> partitions on the eMMC are used to store MAC addresses and Wi-Fi
> calibration EEPROM data.
> 
> Implement an NVMEM provider backed by a block device as typically the
> NVMEM framework is used to have kernel drivers read and use binary data
> from EEPROMs, efuses, flash memory (MTD), ...
> 
> In order to be able to reference hardware partitions on an eMMC, add code
> to bind each hardware partition to a specific firmware subnode.
> 
> Overall, this enables uniform handling across practially all flash
> storage types used for this purpose (MTD, UBI, and now also MMC).
> 
> As part of this series it was necessary to define a device tree schema
> for block devices and partitions on them, which (similar to how it now
> works also for UBI volumes) can be matched by one or more properties.

Since this patch series adds code that opens partitions and reads
from partitions, can that part of the functionality be implemented in
user space? There is already a mechanism for notifying user space about
block device changes, namely udev.

Thanks,

Bart.