| From: |
| Loic Poulain <loic.poulain-AT-oss.qualcomm.com> |
| To: |
| Ulf Hansson <ulfh-AT-kernel.org>, Rob Herring <robh-AT-kernel.org>, Krzysztof Kozlowski <krzk+dt-AT-kernel.org>, Conor Dooley <conor+dt-AT-kernel.org>, Bjorn Andersson <andersson-AT-kernel.org>, Konrad Dybcio <konradybcio-AT-kernel.org>, Jens Axboe <axboe-AT-kernel.dk>, Johannes Berg <johannes-AT-sipsolutions.net>, Jeff Johnson <jjohnson-AT-kernel.org>, Bartosz Golaszewski <brgl-AT-kernel.org>, Marcel Holtmann <marcel-AT-holtmann.org>, Luiz Augusto von Dentz <luiz.dentz-AT-gmail.com>, Balakrishna Godavarthi <quic_bgodavar-AT-quicinc.com>, Rocky Liao <quic_rjliao-AT-quicinc.com>, "David S. Miller" <davem-AT-davemloft.net>, Eric Dumazet <edumazet-AT-google.com>, Jakub Kicinski <kuba-AT-kernel.org>, Paolo Abeni <pabeni-AT-redhat.com>, Simon Horman <horms-AT-kernel.org>, Srinivas Kandagatla <srini-AT-kernel.org>, Andrew Lunn <andrew-AT-lunn.ch>, Heiner Kallweit <hkallweit1-AT-gmail.com>, Russell King <linux-AT-armlinux.org.uk>, Saravana Kannan <saravanak-AT-kernel.org> |
| Subject: |
| [PATCH v3 0/7] Support for block device NVMEM providers |
| Date: |
| Mon, 08 Jun 2026 12:50:37 +0200 |
| Message-ID: |
| <20260608-block-as-nvmem-v3-0-82681f50aa35@oss.qualcomm.com> |
| Cc: |
| linux-mmc-AT-vger.kernel.org, devicetree-AT-vger.kernel.org, linux-kernel-AT-vger.kernel.org, linux-arm-msm-AT-vger.kernel.org, linux-block-AT-vger.kernel.org, linux-wireless-AT-vger.kernel.org, ath10k-AT-lists.infradead.org, linux-bluetooth-AT-vger.kernel.org, netdev-AT-vger.kernel.org, daniel-AT-makrotopia.org, Loic Poulain <loic.poulain-AT-oss.qualcomm.com>, Bartosz Golaszewski <bartosz.golaszewski-AT-oss.qualcomm.com> |
| Archive-link: |
| Article |
On embedded devices, it is common for factory provisioning to store
device-specific information, such as Ethernet or WiFi MAC addresses,
in a dedicated area of an eMMC partition. This avoids the need for
and additional EEPROM/OTP and leverages the persistence of eMMC.
One example is the Arduino UNO-Q, where the WiFi MAC address and the
Bluetooth Device address are stored in the eMMC Boot1 partition.
Until now, accessing this information required a custom bootloader
to read the data and inject it into the Device Tree before handing
control over to the kernel. This approach is fragile and leads to
device-specific workarounds.
Rather than adding a new NVMEM provider specifically to the eMMC
subsystem, the new support operates at the block layer, allowing any
block device to behave like other non-volatile memories such as EEPROM
or OTP.
This series builds on earlier work by Daniel Golle that enables block
devices to act as NVMEM providers:
https://lore.kernel.org/all/6061aa4201030b9bb2f8d03ef32a5...
It also introduces an NVMEM layout description for the Arduino UNO-Q,
allowing device-specific data stored in the eMMC Boot1 partition to
be accessed in a standard way.
WiFi and Ethernet already support retrieving MAC addresses from NVMEM.
Bluetooth requires similar support, which is also addressed.
Note that this is currently limited to MMC-backed block devices, as
only the MMC core associates a firmware node with the block device
(add_disk_fwnode). This can be easily extended in the future to
support additional block drivers.
Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
Changes in v3:
- Fixed missing 'fixed-partitions' compatible in partition (Rob)
- Fixed clashing nvmem cells, document calibration along mac (Sashiko)
- Remove workaround to handle dangling nvmem references after
unregistering, this is a generic nvmem framework issue handled
in Bartosz's series:
https://lore.kernel.org/all/20260429-nvmem-unbind-v3-0-2a...
- Validate mac (is_valid_ether_addr) before copying to output buffer
- Link to v2: https://lore.kernel.org/r/20260507-block-as-nvmem-v2-0-bf...
Changes in v2:
- Fix example nvmem-layout cells to use compatible = "mac-base"
- Squash WiFi MAC and Bluetooth BD address consumer patches into the nvmem layout patch
- Fix possible use-after-free in blk-nvmem: bnv (nvmem priv) linked to nvmem lifetime
- Simplify nvmem-cell-names from items: - const: to plain const:
- Factor out common NVMEM EUI-48 retrieval logic
- Reorder changes
- Link to v1: https://lore.kernel.org/r/20260428-block-as-nvmem-v1-0-6a...
---
Daniel Golle (1):
block: implement NVMEM provider
Loic Poulain (6):
dt-bindings: mmc: Document support for nvmem-layout
dt-bindings: net: wireless: qcom,ath10k: Document NVMEM cells
dt-bindings: bluetooth: qcom: Add NVMEM BD address cell
net: of_net: Add of_get_nvmem_eui48() helper for EUI-48 lookup
Bluetooth: hci_sync: Add NVMEM-backed BD address retrieval
Bluetooth: qca: Set NVMEM BD address quirks when address is invalid
.../devicetree/bindings/mmc/mmc-card.yaml | 29 ++++
.../net/bluetooth/qcom,bluetooth-common.yaml | 9 ++
.../bindings/net/wireless/qcom,ath10k.yaml | 16 ++
arch/arm64/boot/dts/qcom/qrb2210-arduino-imola.dts | 39 +++++
block/Kconfig | 9 ++
block/Makefile | 1 +
block/blk-nvmem.c | 171 +++++++++++++++++++++
drivers/bluetooth/btqca.c | 5 +-
drivers/nvmem/core.c | 13 ++
include/linux/nvmem-consumer.h | 6 +
include/linux/of_net.h | 7 +
include/net/bluetooth/hci.h | 18 +++
net/bluetooth/hci_sync.c | 39 ++++-
net/core/of_net.c | 49 ++++--
14 files changed, 397 insertions(+), 14 deletions(-)
---
base-commit: 47c4835fc0fed583d01d90387b67633950eba2b2
change-id: 20260428-block-as-nvmem-4b308e8bda9a
Best regards,
--
Loic Poulain <loic.poulain@oss.qualcomm.com>
