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* [PATCH v2 0/8] Support for block device NVMEM providers
@ 2026-05-07 15:24 Loic Poulain
  2026-05-07 15:24 ` [PATCH v2 1/8] dt-bindings: mmc: Document support for nvmem-layout Loic Poulain
                   ` (7 more replies)
  0 siblings, 8 replies; 23+ messages in thread
From: Loic Poulain @ 2026-05-07 15:24 UTC (permalink / raw)
  To: Ulf Hansson, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
	Bjorn Andersson, Konrad Dybcio, Jens Axboe, Johannes Berg,
	Jeff Johnson, Bartosz Golaszewski, Marcel Holtmann,
	Luiz Augusto von Dentz, Balakrishna Godavarthi, Rocky Liao,
	David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
	Simon Horman, Srinivas Kandagatla, Andrew Lunn, Heiner Kallweit,
	Russell King, Saravana Kannan
  Cc: linux-mmc, devicetree, linux-kernel, linux-arm-msm, linux-block,
	linux-wireless, ath10k, linux-bluetooth, netdev, daniel,
	Loic Poulain, Konrad Dybcio

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/6061aa4201030b9bb2f8d03ef32a564fdb786ed1.1709667858.git.daniel@makrotopia.org/

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 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-v1-0-6ad23e75190a@oss.qualcomm.com

---
Daniel Golle (1):
      block: implement NVMEM provider

Loic Poulain (7):
      dt-bindings: mmc: Document support for nvmem-layout
      dt-bindings: net: wireless: qcom,ath10k: Add NVMEM MAC address cell
      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
      arm64: dts: qcom: arduino-imola: Describe NVMEM layout for WiFi/BT addresses

 .../devicetree/bindings/mmc/mmc-card.yaml          |  24 +++
 .../net/bluetooth/qcom,bluetooth-common.yaml       |   9 +
 .../bindings/net/wireless/qcom,ath10k.yaml         |   9 +
 arch/arm64/boot/dts/qcom/qrb2210-arduino-imola.dts |  34 ++++
 block/Kconfig                                      |   9 +
 block/Makefile                                     |   1 +
 block/blk-nvmem.c                                  | 188 +++++++++++++++++++++
 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                                  |  47 ++++--
 14 files changed, 395 insertions(+), 14 deletions(-)
---
base-commit: 47c4835fc0fed583d01d90387b67633950eba2b2
change-id: 20260428-block-as-nvmem-4b308e8bda9a

Best regards,
-- 
Loic Poulain <loic.poulain@oss.qualcomm.com>



^ permalink raw reply	[flat|nested] 23+ messages in thread
* [PATCH v5 1/9] block: partitions: of: Skip child nodes without reg property
@ 2026-06-12 13:20 Loic Poulain
  2026-06-12 16:24 ` Support for block device NVMEM providers bluez.test.bot
  0 siblings, 1 reply; 23+ messages in thread
From: Loic Poulain @ 2026-06-12 13:20 UTC (permalink / raw)
  To: Ulf Hansson, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
	Bjorn Andersson, Konrad Dybcio, Jens Axboe, Johannes Berg,
	Jeff Johnson, Bartosz Golaszewski, Marcel Holtmann,
	Luiz Augusto von Dentz, Balakrishna Godavarthi, Rocky Liao,
	David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
	Simon Horman, Srinivas Kandagatla, Andrew Lunn, Heiner Kallweit,
	Russell King, Saravana Kannan
  Cc: linux-mmc, devicetree, linux-kernel, linux-arm-msm, linux-block,
	linux-wireless, ath10k, linux-bluetooth, netdev, daniel,
	Loic Poulain

Child nodes of a fixed-partitions node are not necessarily partition
entries, for example an nvmem-layout node has no reg property. The
current code passes a NULL reg pointer and uninitialized len to the
length check, which can result in a kernel panic or silent failure to
register any partitions.

Fix validate_of_partition() to return a skip indicator when no reg
property is present. Guard add_of_partition() with a reg property
check for the same reason.

Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
 block/partitions/of.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/block/partitions/of.c b/block/partitions/of.c
index c22b6066109819c71568f73e8db8833d196b1cf6..534e02a9d85f62611d880af9b302d9fd49aa4d46 100644
--- a/block/partitions/of.c
+++ b/block/partitions/of.c
@@ -15,6 +15,10 @@ static int validate_of_partition(struct device_node *np, int slot)
 	int a_cells = of_n_addr_cells(np);
 	int s_cells = of_n_size_cells(np);
 
+	/* Skip nodes without a reg property (e.g. nvmem-layout) */
+	if (!reg)
+		return 1;
+
 	/* Make sure reg len match the expected addr and size cells */
 	if (len / sizeof(*reg) != a_cells + s_cells)
 		return -EINVAL;
@@ -80,14 +84,15 @@ int of_partition(struct parsed_partitions *state)
 	slot = 1;
 	/* Validate parition offset and size */
 	for_each_child_of_node(partitions_np, np) {
-		if (validate_of_partition(np, slot)) {
+		int err = validate_of_partition(np, slot);
+
+		if (err < 0) {
 			of_node_put(np);
 			of_node_put(partitions_np);
-
 			return -1;
 		}
-
-		slot++;
+		if (!err)
+			slot++;
 	}
 
 	slot = 1;
@@ -97,9 +102,10 @@ int of_partition(struct parsed_partitions *state)
 			break;
 		}
 
-		add_of_partition(state, slot, np);
-
-		slot++;
+		if (of_property_present(np, "reg")) {
+			add_of_partition(state, slot, np);
+			slot++;
+		}
 	}
 
 	seq_buf_puts(&state->pp_buf, "\n");

-- 
2.34.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread
* [PATCH v4 1/8] dt-bindings: mmc: Document support for nvmem-layout
@ 2026-06-09  7:52 Loic Poulain
  2026-06-09  9:31 ` Support for block device NVMEM providers bluez.test.bot
  0 siblings, 1 reply; 23+ messages in thread
From: Loic Poulain @ 2026-06-09  7:52 UTC (permalink / raw)
  To: Ulf Hansson, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
	Bjorn Andersson, Konrad Dybcio, Jens Axboe, Johannes Berg,
	Jeff Johnson, Bartosz Golaszewski, Marcel Holtmann,
	Luiz Augusto von Dentz, Balakrishna Godavarthi, Rocky Liao,
	David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
	Simon Horman, Srinivas Kandagatla, Andrew Lunn, Heiner Kallweit,
	Russell King, Saravana Kannan
  Cc: linux-mmc, devicetree, linux-kernel, linux-arm-msm, linux-block,
	linux-wireless, ath10k, linux-bluetooth, netdev, daniel,
	Loic Poulain, Bartosz Golaszewski

Add support for an nvmem-layout subnode under an eMMC hardware
partition. This allows the partition to be exposed as an NVMEM
provider and its internal layout to be described. For example,
an eMMC boot partition can be used to store device-specific
information such as a WiFi MAC address.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
 .../devicetree/bindings/mmc/mmc-card.yaml          | 29 ++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/mmc-card.yaml b/Documentation/devicetree/bindings/mmc/mmc-card.yaml
index a61d6c96df759102f9c1fbfd548b026a77921cae..ca907ad73095925b234b119948f94ae81e698c86 100644
--- a/Documentation/devicetree/bindings/mmc/mmc-card.yaml
+++ b/Documentation/devicetree/bindings/mmc/mmc-card.yaml
@@ -40,6 +40,9 @@ patternProperties:
         contains:
           const: fixed-partitions
 
+      nvmem-layout:
+        $ref: /schemas/nvmem/layouts/nvmem-layout.yaml
+
 required:
   - compatible
   - reg
@@ -86,6 +89,32 @@ examples:
                     read-only;
                 };
             };
+
+            partitions-boot2 {
+                compatible = "fixed-partitions";
+
+                #address-cells = <1>;
+                #size-cells = <1>;
+
+                nvmem-layout {
+                    compatible = "fixed-layout";
+
+                    #address-cells = <1>;
+                    #size-cells = <1>;
+
+                    mac-addr@4400 {
+                        compatible = "mac-base";
+                        reg = <0x4400 0x6>;
+                        #nvmem-cell-cells = <1>;
+                    };
+
+                    bd-addr@5400 {
+                        compatible = "mac-base";
+                        reg = <0x5400 0x6>;
+                        #nvmem-cell-cells = <1>;
+                    };
+                };
+            };
         };
     };
 

-- 
2.34.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread
* [PATCH v3 1/7] dt-bindings: mmc: Document support for nvmem-layout
@ 2026-06-08 10:50 Loic Poulain
  2026-06-08 12:12 ` Support for block device NVMEM providers bluez.test.bot
  0 siblings, 1 reply; 23+ messages in thread
From: Loic Poulain @ 2026-06-08 10:50 UTC (permalink / raw)
  To: Ulf Hansson, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
	Bjorn Andersson, Konrad Dybcio, Jens Axboe, Johannes Berg,
	Jeff Johnson, Bartosz Golaszewski, Marcel Holtmann,
	Luiz Augusto von Dentz, Balakrishna Godavarthi, Rocky Liao,
	David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
	Simon Horman, Srinivas Kandagatla, Andrew Lunn, Heiner Kallweit,
	Russell King, Saravana Kannan
  Cc: linux-mmc, devicetree, linux-kernel, linux-arm-msm, linux-block,
	linux-wireless, ath10k, linux-bluetooth, netdev, daniel,
	Loic Poulain

Add support for an nvmem-layout subnode under an eMMC hardware
partition. This allows the partition to be exposed as an NVMEM
provider and its internal layout to be described. For example,
an eMMC boot partition can be used to store device-specific
information such as a WiFi MAC address.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
 .../devicetree/bindings/mmc/mmc-card.yaml          | 29 ++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/mmc-card.yaml b/Documentation/devicetree/bindings/mmc/mmc-card.yaml
index a61d6c96df759102f9c1fbfd548b026a77921cae..ca907ad73095925b234b119948f94ae81e698c86 100644
--- a/Documentation/devicetree/bindings/mmc/mmc-card.yaml
+++ b/Documentation/devicetree/bindings/mmc/mmc-card.yaml
@@ -40,6 +40,9 @@ patternProperties:
         contains:
           const: fixed-partitions
 
+      nvmem-layout:
+        $ref: /schemas/nvmem/layouts/nvmem-layout.yaml
+
 required:
   - compatible
   - reg
@@ -86,6 +89,32 @@ examples:
                     read-only;
                 };
             };
+
+            partitions-boot2 {
+                compatible = "fixed-partitions";
+
+                #address-cells = <1>;
+                #size-cells = <1>;
+
+                nvmem-layout {
+                    compatible = "fixed-layout";
+
+                    #address-cells = <1>;
+                    #size-cells = <1>;
+
+                    mac-addr@4400 {
+                        compatible = "mac-base";
+                        reg = <0x4400 0x6>;
+                        #nvmem-cell-cells = <1>;
+                    };
+
+                    bd-addr@5400 {
+                        compatible = "mac-base";
+                        reg = <0x5400 0x6>;
+                        #nvmem-cell-cells = <1>;
+                    };
+                };
+            };
         };
     };
 

-- 
2.34.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread
* [PATCH 1/9] dt-bindings: mmc: Document support for nvmem-layout
@ 2026-04-28 14:23 Loic Poulain
  2026-04-28 17:44 ` Support for block device NVMEM providers bluez.test.bot
  0 siblings, 1 reply; 23+ messages in thread
From: Loic Poulain @ 2026-04-28 14:23 UTC (permalink / raw)
  To: Ulf Hansson, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
	Bjorn Andersson, Konrad Dybcio, Jens Axboe, Johannes Berg,
	Jeff Johnson, Bartosz Golaszewski, Marcel Holtmann,
	Luiz Augusto von Dentz, Balakrishna Godavarthi, Rocky Liao,
	David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
	Simon Horman
  Cc: linux-mmc, devicetree, linux-kernel, linux-arm-msm, linux-block,
	linux-wireless, ath10k, linux-bluetooth, netdev, daniel,
	Loic Poulain

Add support for an nvmem-layout subnode under an eMMC hardware
partition. This allows the partition to be exposed as an NVMEM
provider and its internal layout to be described. For example,
an eMMC boot partition can be used to store device-specific
information such as a WiFi MAC address.

Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
 Documentation/devicetree/bindings/mmc/mmc-card.yaml | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/mmc-card.yaml b/Documentation/devicetree/bindings/mmc/mmc-card.yaml
index a61d6c96df759102f9c1fbfd548b026a77921cae..e01fc82ab8520a31196475b18acb5e839e1bf71f 100644
--- a/Documentation/devicetree/bindings/mmc/mmc-card.yaml
+++ b/Documentation/devicetree/bindings/mmc/mmc-card.yaml
@@ -40,6 +40,9 @@ patternProperties:
         contains:
           const: fixed-partitions
 
+      nvmem-layout:
+        $ref: /schemas/nvmem/layouts/nvmem-layout.yaml
+
 required:
   - compatible
   - reg
@@ -86,6 +89,23 @@ examples:
                     read-only;
                 };
             };
+
+            partitions-boot2 {
+                nvmem-layout {
+                    compatible = "fixed-layout";
+
+                    #address-cells = <1>;
+                    #size-cells = <1>;
+
+                    mac-addr@4400 {
+                        reg = <0x4400 0x6>;
+                    };
+
+                    bd-addr@5400 {
+                        reg = <0x5400 0x6>;
+                    };
+                };
+            };
         };
     };
 

-- 
2.34.1



^ permalink raw reply related	[flat|nested] 23+ messages in thread
end of thread, other threads:[~2026-06-12 16:24 UTC | newest]

Thread overview: 23+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-05-07 15:24 [PATCH v2 0/8] Support for block device NVMEM providers Loic Poulain
2026-05-07 15:24 ` [PATCH v2 1/8] dt-bindings: mmc: Document support for nvmem-layout Loic Poulain
2026-05-07 16:19   ` Support for block device NVMEM providers bluez.test.bot
2026-05-13 22:42   ` [PATCH v2 1/8] dt-bindings: mmc: Document support for nvmem-layout Rob Herring
2026-05-07 15:24 ` [PATCH v2 2/8] dt-bindings: net: wireless: qcom,ath10k: Add NVMEM MAC address cell Loic Poulain
2026-05-08 18:20   ` sashiko-bot
2026-05-07 15:24 ` [PATCH v2 3/8] dt-bindings: bluetooth: qcom: Add NVMEM BD " Loic Poulain
2026-05-07 15:24 ` [PATCH v2 4/8] block: implement NVMEM provider Loic Poulain
2026-05-08 18:20   ` sashiko-bot
2026-05-11 11:27   ` Bartosz Golaszewski
2026-05-07 15:24 ` [PATCH v2 5/8] net: of_net: Add of_get_nvmem_eui48() helper for EUI-48 lookup Loic Poulain
2026-05-08 18:20   ` sashiko-bot
2026-05-11 10:36   ` Bartosz Golaszewski
2026-05-07 15:24 ` [PATCH v2 6/8] Bluetooth: hci_sync: Add NVMEM-backed BD address retrieval Loic Poulain
2026-05-08 18:20   ` sashiko-bot
2026-05-07 15:24 ` [PATCH v2 7/8] Bluetooth: qca: Set NVMEM BD address quirks when address is invalid Loic Poulain
2026-05-11 11:29   ` Bartosz Golaszewski
2026-05-07 15:24 ` [PATCH v2 8/8] arm64: dts: qcom: arduino-imola: Describe NVMEM layout for WiFi/BT addresses Loic Poulain
2026-05-11 11:30   ` Bartosz Golaszewski
  -- strict thread matches above, loose matches on Subject: below --
2026-06-12 13:20 [PATCH v5 1/9] block: partitions: of: Skip child nodes without reg property Loic Poulain
2026-06-12 16:24 ` Support for block device NVMEM providers bluez.test.bot
2026-06-09  7:52 [PATCH v4 1/8] dt-bindings: mmc: Document support for nvmem-layout Loic Poulain
2026-06-09  9:31 ` Support for block device NVMEM providers bluez.test.bot
2026-06-08 10:50 [PATCH v3 1/7] dt-bindings: mmc: Document support for nvmem-layout Loic Poulain
2026-06-08 12:12 ` Support for block device NVMEM providers bluez.test.bot
2026-04-28 14:23 [PATCH 1/9] dt-bindings: mmc: Document support for nvmem-layout Loic Poulain
2026-04-28 17:44 ` Support for block device NVMEM providers bluez.test.bot

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