* [PATCH v5 1/3] dt-bindings: mfd: mediatek: mt6397: add mt6323 PMIC EFUSE
2026-09-21 7:50 [PATCH v5 0/3] nvmem: add support for the MediaTek mt6323 PMIC Roman Vivchar via B4 Relay
@ 2026-09-21 7:50 ` Roman Vivchar via B4 Relay
2026-09-21 7:50 ` [PATCH v5 2/3] nvmem: add mt6323 PMIC EFUSE driver Roman Vivchar via B4 Relay
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Roman Vivchar via B4 Relay @ 2026-09-21 7:50 UTC (permalink / raw)
To: Sen Chu, Sean Wang, Macpaul Lin, Lee Jones, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Matthias Brugger,
AngeloGioacchino Del Regno, Srinivas Kandagatla, Roman Vivchar
Cc: Andy Shevchenko, linux-pm, devicetree, linux-kernel,
linux-arm-kernel, linux-mediatek, Ben Grisdale, Conor Dooley
From: Roman Vivchar <rva333@protonmail.com>
The MediaTek mt6323 PMIC includes an EFUSE used for storing calibration
data.
Add the devicetree binding documentation for the MediaTek mt6323 EFUSE.
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Roman Vivchar <rva333@protonmail.com>
---
.../devicetree/bindings/mfd/mediatek,mt6397.yaml | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/Documentation/devicetree/bindings/mfd/mediatek,mt6397.yaml b/Documentation/devicetree/bindings/mfd/mediatek,mt6397.yaml
index 3cbc0dc12c31..d2de227ae7a6 100644
--- a/Documentation/devicetree/bindings/mfd/mediatek,mt6397.yaml
+++ b/Documentation/devicetree/bindings/mfd/mediatek,mt6397.yaml
@@ -159,6 +159,23 @@ properties:
required:
- compatible
+ efuse:
+ type: object
+ unevaluatedProperties: false
+ description:
+ The efuse is responsible for storing calibration data, such as thermal
+ sensor calibration.
+
+ properties:
+ compatible:
+ const: mediatek,mt6323-efuse
+
+ nvmem-layout:
+ $ref: /schemas/nvmem/layouts/nvmem-layout.yaml#
+
+ required:
+ - compatible
+
leds:
type: object
additionalProperties: false
@@ -307,6 +324,10 @@ examples:
interrupt-controller;
#interrupt-cells = <2>;
+ efuse {
+ compatible = "mediatek,mt6323-efuse";
+ };
+
leds {
compatible = "mediatek,mt6323-led";
#address-cells = <1>;
--
2.55.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v5 2/3] nvmem: add mt6323 PMIC EFUSE driver
2026-09-21 7:50 [PATCH v5 0/3] nvmem: add support for the MediaTek mt6323 PMIC Roman Vivchar via B4 Relay
2026-09-21 7:50 ` [PATCH v5 1/3] dt-bindings: mfd: mediatek: mt6397: add mt6323 PMIC EFUSE Roman Vivchar via B4 Relay
@ 2026-09-21 7:50 ` Roman Vivchar via B4 Relay
2026-09-21 8:01 ` sashiko-bot
2026-09-21 7:50 ` [PATCH v5 3/3] ARM: dts: mediatek: mt6323: add EFUSE support Roman Vivchar via B4 Relay
2026-09-21 9:30 ` (subset) [PATCH v5 0/3] nvmem: add support for the MediaTek mt6323 PMIC Srinivas Kandagatla
3 siblings, 1 reply; 6+ messages in thread
From: Roman Vivchar via B4 Relay @ 2026-09-21 7:50 UTC (permalink / raw)
To: Sen Chu, Sean Wang, Macpaul Lin, Lee Jones, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Matthias Brugger,
AngeloGioacchino Del Regno, Srinivas Kandagatla, Roman Vivchar
Cc: Andy Shevchenko, linux-pm, devicetree, linux-kernel,
linux-arm-kernel, linux-mediatek, Ben Grisdale
From: Roman Vivchar <rva333@protonmail.com>
Add support for the EFUSE controller found in the Mediatek MT6323 PMIC.
The MT6323 EFUSE stores 24 bytes of hardware-related data, such as
thermal sensor calibration values.
Tested-by: Ben Grisdale <bengris32@protonmail.ch> # Amazon Echo Dot (2nd Generation)
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Roman Vivchar <rva333@protonmail.com>
---
MAINTAINERS | 5 +++
drivers/nvmem/Kconfig | 11 ++++++
drivers/nvmem/Makefile | 2 ++
drivers/nvmem/mt6323-efuse.c | 83 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 101 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 3a19da74d00c..6ec0ed61260c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16718,6 +16718,11 @@ S: Maintained
F: drivers/iio/adc/mt6323-auxadc.c
F: include/dt-bindings/iio/adc/mediatek,mt6323-auxadc.h
+MEDIATEK MT6323 PMIC NVMEM DRIVER
+M: Roman Vivchar <rva333@protonmail.com>
+S: Maintained
+F: drivers/nvmem/mt6323-efuse.c
+
MEDIATEK MT6735 CLOCK & RESET DRIVERS
M: Yassine Oudjana <y.oudjana@protonmail.com>
L: linux-clk@vger.kernel.org
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index c36c2a4c2a0b..5115c46beb97 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -328,6 +328,17 @@ config NVMEM_MTK_EFUSE
This driver can also be built as a module. If so, the module
will be called efuse-mtk.
+config NVMEM_MT6323_EFUSE
+ tristate "MediaTek MT6323 PMIC EFUSE support"
+ depends on ARCH_MEDIATEK || COMPILE_TEST
+ depends on MFD_MT6397
+ help
+ This is a driver to access hardware related data like sensor
+ calibration, etc.
+
+ This driver can also be built as a module. If so, the module
+ will be called efuse-mt6323.
+
config NVMEM_MXS_OCOTP
tristate "Freescale MXS On-Chip OTP Memory Support"
depends on ARCH_MXS || COMPILE_TEST
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 2bbfb9ff1885..5e70bad9f0f9 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -53,6 +53,8 @@ obj-$(CONFIG_NVMEM_MESON_MX_EFUSE) += nvmem_meson_mx_efuse.o
nvmem_meson_mx_efuse-y := meson-mx-efuse.o
obj-$(CONFIG_NVMEM_MICROCHIP_OTPC) += nvmem-microchip-otpc.o
nvmem-microchip-otpc-y := microchip-otpc.o
+obj-$(CONFIG_NVMEM_MT6323_EFUSE) += nvmem_mt6323-efuse.o
+nvmem_mt6323-efuse-y := mt6323-efuse.o
obj-$(CONFIG_NVMEM_MTK_EFUSE) += nvmem_mtk-efuse.o
nvmem_mtk-efuse-y := mtk-efuse.o
obj-$(CONFIG_NVMEM_MXS_OCOTP) += nvmem-mxs-ocotp.o
diff --git a/drivers/nvmem/mt6323-efuse.c b/drivers/nvmem/mt6323-efuse.c
new file mode 100644
index 000000000000..de5e30215c22
--- /dev/null
+++ b/drivers/nvmem/mt6323-efuse.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2026 Roman Vivchar <rva333@protonmail.com>
+ */
+
+#include <linux/err.h>
+#include <linux/mfd/mt6397/core.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+#include <linux/mfd/mt6323/registers.h>
+
+#define MT6323_EFUSE_DOUT_BASE MT6323_EFUSE_DOUT_0_15
+#define MT6323_EFUSE_SIZE 24
+
+static int mt6323_efuse_read(void *context, unsigned int offset, void *val,
+ size_t bytes)
+{
+ struct regmap *map = context;
+ u16 *buf = val;
+ u32 tmp;
+ int ret;
+
+ /*
+ * A manual loop using regmap_read is required because PWRAP is not
+ * a continuous MMIO space, but rather a FSM that doesn't implement the
+ * necessary read callback for the regmap_read_raw and regmap_read_bulk
+ * functions.
+ */
+ for (size_t i = 0; i < bytes; i += sizeof(*buf)) {
+ ret = regmap_read(map, MT6323_EFUSE_DOUT_BASE + offset + i, &tmp);
+ if (ret)
+ return ret;
+
+ *buf++ = tmp;
+ }
+
+ return 0;
+}
+
+static int mt6323_efuse_probe(struct platform_device *pdev)
+{
+ struct mt6397_chip *mt6323 = dev_get_drvdata(pdev->dev.parent);
+ struct device *dev = &pdev->dev;
+ struct nvmem_config config = {
+ .name = "mt6323-efuse",
+ .stride = 2,
+ .word_size = 2,
+ .size = MT6323_EFUSE_SIZE,
+ .reg_read = mt6323_efuse_read,
+ };
+ struct nvmem_device *nvmem;
+
+ if (!mt6323 || !mt6323->regmap)
+ return dev_err_probe(dev, -ENODEV, "failed to get parent\n");
+
+ config.dev = dev;
+ config.priv = mt6323->regmap;
+
+ nvmem = devm_nvmem_register(dev, &config);
+ return PTR_ERR_OR_ZERO(nvmem);
+}
+
+static const struct of_device_id mt6323_efuse_of_match[] = {
+ { .compatible = "mediatek,mt6323-efuse" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, mt6323_efuse_of_match);
+
+static struct platform_driver mt6323_efuse_driver = {
+ .probe = mt6323_efuse_probe,
+ .driver = {
+ .name = "mt6323-efuse",
+ .of_match_table = mt6323_efuse_of_match,
+ },
+};
+module_platform_driver(mt6323_efuse_driver);
+
+MODULE_DESCRIPTION("MediaTek MT6323 PMIC EFUSE driver");
+MODULE_LICENSE("GPL");
--
2.55.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH v5 2/3] nvmem: add mt6323 PMIC EFUSE driver
2026-09-21 7:50 ` [PATCH v5 2/3] nvmem: add mt6323 PMIC EFUSE driver Roman Vivchar via B4 Relay
@ 2026-09-21 8:01 ` sashiko-bot
0 siblings, 0 replies; 6+ messages in thread
From: sashiko-bot @ 2026-09-21 8:01 UTC (permalink / raw)
To: Roman Vivchar; +Cc: devicetree, robh, conor+dt
Thank you for your contribution! Sashiko AI review found 4 potential issue(s) to consider:
- [High] nvmem: buffer overflow and unaligned memory access in efuse read loop
- [Medium] nvmem: EFUSE data exposed with host-dependent endianness
- [Medium] nvmem: NULL pointer dereference in probe when parent is missing
- [Medium] nvmem: module autoloading fails without MODULE_ALIAS
--
commit 3543415716c7fda0e6f5e6edb62e4ed761b35afd
Author: Roman Vivchar <rva333@protonmail.com>
nvmem: add mt6323 PMIC EFUSE driver
This commit adds support for the EFUSE controller found in the Mediatek
MT6323 PMIC. The MT6323 EFUSE stores 24 bytes of hardware-related data,
such as thermal sensor calibration values.
diff --git a/drivers/nvmem/mt6323-efuse.c b/drivers/nvmem/mt6323-efuse.c
new file mode 100644
index 0000000000000..de5e30215c22d
--- /dev/null
+++ b/drivers/nvmem/mt6323-efuse.c
[ ... ]
> +static int mt6323_efuse_read(void *context, unsigned int offset, void *val,
> + size_t bytes)
> +{
> + struct regmap *map = context;
> + u16 *buf = val;
> + u32 tmp;
> + int ret;
> +
> + /*
> + * A manual loop using regmap_read is required because PWRAP is not
> + * a continuous MMIO space, but rather a FSM that doesn't implement the
> + * necessary read callback for the regmap_read_raw and regmap_read_bulk
> + * functions.
> + */
> + for (size_t i = 0; i < bytes; i += sizeof(*buf)) {
[Severity: High]
Could this loop overflow the allocated val buffer and cause unaligned memory
accesses?
The NVMEM core API nvmem_device_read() does not enforce that the requested
bytes count is a multiple of word_size. If an in-kernel consumer requests an
odd number of bytes (for example, 1 or 3), the loop will run an extra
iteration and unconditionally write a full 16-bit word. This will overflow
the caller's allocated val buffer by 1 byte.
Additionally, if val is not 16-bit aligned, this causes an unaligned memory
access.
> + ret = regmap_read(map, MT6323_EFUSE_DOUT_BASE + offset + i, &tmp);
> + if (ret)
> + return ret;
> +
> + *buf++ = tmp;
[Severity: Medium]
Does this expose the EFUSE data with a host-dependent endianness?
The regmap_read() function returns a CPU-endian 32-bit integer, which is
assigned to tmp. Writing this integer into a 16-bit buffer using native CPU
byte order means that on big-endian architectures, the bytes will be swapped
compared to little-endian architectures, breaking the expected NVMEM byte
stream consistency.
> + }
> +
> + return 0;
> +}
> +
> +static int mt6323_efuse_probe(struct platform_device *pdev)
> +{
> + struct mt6397_chip *mt6323 = dev_get_drvdata(pdev->dev.parent);
[Severity: Medium]
Will this cause a NULL pointer dereference if the parent device pointer is
missing?
The driver has an of_match_table. If it is instantiated directly from a root
Device Tree node rather than being instantiated as an MFD child, the parent
device pointer pdev->dev.parent will be NULL. Calling dev_get_drvdata() on a
NULL parent dereferences it immediately without checks, leading to a crash.
[ ... ]
> +static struct platform_driver mt6323_efuse_driver = {
> + .probe = mt6323_efuse_probe,
> + .driver = {
> + .name = "mt6323-efuse",
> + .of_match_table = mt6323_efuse_of_match,
> + },
> +};
> +module_platform_driver(mt6323_efuse_driver);
> +
> +MODULE_DESCRIPTION("MediaTek MT6323 PMIC EFUSE driver");
> +MODULE_LICENSE("GPL");
[Severity: Medium]
Will module autoloading fail without a MODULE_ALIAS declaration here?
On systems where the Device Tree lacks the mediatek,mt6323-efuse node, the
MFD core will still instantiate the child device by name, producing a modalias
of platform:mt6323-efuse. Because the driver lacks a MODULE_ALIAS declaration
for platform:mt6323-efuse, udev cannot match the modalias, and the module
might never be automatically loaded on boot.
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260921-mt6323-nvmem-v5-0-2f5d308369f0@protonmail.com?part=2
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v5 3/3] ARM: dts: mediatek: mt6323: add EFUSE support
2026-09-21 7:50 [PATCH v5 0/3] nvmem: add support for the MediaTek mt6323 PMIC Roman Vivchar via B4 Relay
2026-09-21 7:50 ` [PATCH v5 1/3] dt-bindings: mfd: mediatek: mt6397: add mt6323 PMIC EFUSE Roman Vivchar via B4 Relay
2026-09-21 7:50 ` [PATCH v5 2/3] nvmem: add mt6323 PMIC EFUSE driver Roman Vivchar via B4 Relay
@ 2026-09-21 7:50 ` Roman Vivchar via B4 Relay
2026-09-21 9:30 ` (subset) [PATCH v5 0/3] nvmem: add support for the MediaTek mt6323 PMIC Srinivas Kandagatla
3 siblings, 0 replies; 6+ messages in thread
From: Roman Vivchar via B4 Relay @ 2026-09-21 7:50 UTC (permalink / raw)
To: Sen Chu, Sean Wang, Macpaul Lin, Lee Jones, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Matthias Brugger,
AngeloGioacchino Del Regno, Srinivas Kandagatla, Roman Vivchar
Cc: Andy Shevchenko, linux-pm, devicetree, linux-kernel,
linux-arm-kernel, linux-mediatek, Ben Grisdale
From: Roman Vivchar <rva333@protonmail.com>
Add the devicetree node for the mt6323 efuse.
Tested-by: Ben Grisdale <bengris32@protonmail.ch> # Amazon Echo Dot (2nd Generation)
Signed-off-by: Roman Vivchar <rva333@protonmail.com>
---
arch/arm/boot/dts/mediatek/mt6323.dtsi | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm/boot/dts/mediatek/mt6323.dtsi b/arch/arm/boot/dts/mediatek/mt6323.dtsi
index c070f4b0936c..c2d08d29cee7 100644
--- a/arch/arm/boot/dts/mediatek/mt6323.dtsi
+++ b/arch/arm/boot/dts/mediatek/mt6323.dtsi
@@ -19,6 +19,10 @@ mt6323_adc: adc {
#io-channel-cells = <1>;
};
+ efuse {
+ compatible = "mediatek,mt6323-efuse";
+ };
+
mt6323_leds: leds {
compatible = "mediatek,mt6323-led";
#address-cells = <1>;
--
2.55.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: (subset) [PATCH v5 0/3] nvmem: add support for the MediaTek mt6323 PMIC
2026-09-21 7:50 [PATCH v5 0/3] nvmem: add support for the MediaTek mt6323 PMIC Roman Vivchar via B4 Relay
` (2 preceding siblings ...)
2026-09-21 7:50 ` [PATCH v5 3/3] ARM: dts: mediatek: mt6323: add EFUSE support Roman Vivchar via B4 Relay
@ 2026-09-21 9:30 ` Srinivas Kandagatla
3 siblings, 0 replies; 6+ messages in thread
From: Srinivas Kandagatla @ 2026-09-21 9:30 UTC (permalink / raw)
To: Sen Chu, Sean Wang, Macpaul Lin, Lee Jones, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Matthias Brugger,
AngeloGioacchino Del Regno, Roman Vivchar
Cc: Andy Shevchenko, linux-pm, devicetree, linux-kernel,
linux-arm-kernel, linux-mediatek, Ben Grisdale, Conor Dooley
On Mon, 21 Sep 2026 10:50:01 +0300, Roman Vivchar wrote:
> This series adds support for the EFUSE found on the MediaTek mt6323 PMIC.
>
> Tested on the MediaTek mt6572 and mt8163 SoCs (Ben), both paired with a
> mt6323.
>
>
Applied, thanks!
[1/3] dt-bindings: mfd: mediatek: mt6397: add mt6323 PMIC EFUSE
commit: c29abe7af10aa891da6c0b68274258232ee3a1a7
[2/3] nvmem: add mt6323 PMIC EFUSE driver
commit: 70a3d85e936cb43165331b9ea470b311a5beeeaa
Best regards,
--
Srinivas Kandagatla <srini@kernel.org>
^ permalink raw reply [flat|nested] 6+ messages in thread