[PATCH v2] HID: i2c-hid: Refactor _DSM helper and add i2c-hid-acpi-prp0001 driver

[PATCH v2] HID: i2c-hid: Refactor _DSM helper and add i2c-hid-acpi-prp0001 driver

[谢致邦 (XIE Zhibang)]

Move the _DSM call that gets the HID descriptor address from
i2c-hid-acpi.c into i2c-hid-acpi.h as a static inline so both the ACPI
and the new PRP0001 driver can use it. While refactoring, move the
blacklist check and the _DSM call to the top of probe() to avoid a
pointless alloc when the device is blacklisted or does not implement the
_DSM.

Some devices, for example the Lenovo KaiTian N60d and Inspur CP300L3,
are declared with _HID "PRP0001" and _DSD compatible "hid-over-i2c" but
lack "hid-descr-addr" from the _DSD and provide the HID descriptor
address only through an ACPI _DSM. The OF driver fails to probe them
because it requires hid-descr-addr. Add a new driver that handles these
devices by calling the shared _DSM helper.

Fixes: b33752c30023 ("HID: i2c-hid: Reorganize so ACPI and OF are separate modules")
Signed-off-by: 谢致邦 (XIE Zhibang) <Yeking@Red54.com>
---
v2: Name the unused parameter and document why
acpi_device_fix_up_power() is skipped.

 drivers/hid/i2c-hid/Kconfig                | 18 ++++
 drivers/hid/i2c-hid/Makefile               |  1 +
 drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c | 96 ++++++++++++++++++++++
 drivers/hid/i2c-hid/i2c-hid-acpi.c         | 48 +++--------
 drivers/hid/i2c-hid/i2c-hid-acpi.h         | 32 ++++++++
 5 files changed, 159 insertions(+), 36 deletions(-)
 create mode 100644 drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
 create mode 100644 drivers/hid/i2c-hid/i2c-hid-acpi.h

diff --git a/drivers/hid/i2c-hid/Kconfig b/drivers/hid/i2c-hid/Kconfig
index e8d51f410cc1..7db8b2abff78 100644
--- a/drivers/hid/i2c-hid/Kconfig
+++ b/drivers/hid/i2c-hid/Kconfig
@@ -22,6 +22,24 @@ config I2C_HID_ACPI
 	  will be called i2c-hid-acpi.  It will also build/depend on the
 	  module i2c-hid.
 
+config I2C_HID_ACPI_PRP0001
+	tristate "Driver for PRP0001 devices missing hid-descr-addr"
+	depends on ACPI
+	depends on DRM || !DRM
+	select I2C_HID_CORE
+	help
+	  Say Y here if you want support for I2C HID touchpads that
+	  are declared with _HID "PRP0001" and _DSD compatible
+	  "hid-over-i2c" but lack the "hid-descr-addr" property from
+	  the _DSD. The HID descriptor address is instead provided
+	  through an ACPI _DSM. Known affected devices include the
+	  Lenovo KaiTian N60d and Inspur CP300L3.
+
+	  If unsure, say N.
+
+	  This support is also available as a module. If so, the
+	  module will be called i2c-hid-acpi-prp0001.
+
 config I2C_HID_OF
 	tristate "HID over I2C transport layer Open Firmware driver"
 	# No "depends on OF" because this can also be used for manually
diff --git a/drivers/hid/i2c-hid/Makefile b/drivers/hid/i2c-hid/Makefile
index 55bd5e0f35af..da420c1a8ec6 100644
--- a/drivers/hid/i2c-hid/Makefile
+++ b/drivers/hid/i2c-hid/Makefile
@@ -9,6 +9,7 @@ i2c-hid-objs					=  i2c-hid-core.o
 i2c-hid-$(CONFIG_DMI)				+= i2c-hid-dmi-quirks.o
 
 obj-$(CONFIG_I2C_HID_ACPI)			+= i2c-hid-acpi.o
+obj-$(CONFIG_I2C_HID_ACPI_PRP0001)		+= i2c-hid-acpi-prp0001.o
 obj-$(CONFIG_I2C_HID_OF)			+= i2c-hid-of.o
 obj-$(CONFIG_I2C_HID_OF_ELAN)			+= i2c-hid-of-elan.o
 obj-$(CONFIG_I2C_HID_OF_GOODIX)			+= i2c-hid-of-goodix.o
diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c b/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
new file mode 100644
index 000000000000..b6b64e868f36
--- /dev/null
+++ b/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * HID over I2C driver for PRP0001 devices missing hid-descr-addr
+ *
+ * Some devices, for example the Lenovo KaiTian N60d and Inspur CP300L3, use
+ * _HID "PRP0001" with _DSD compatible "hid-over-i2c" but lack "hid-descr-addr"
+ * from the _DSD. The HID descriptor address is provided only through an ACPI
+ * _DSM. The TPD0 node in the DSDT shows _DSM Function 1 returning 0x20.
+ *
+ * Copyright (C) 2026 谢致邦 (XIE Zhibang) <Yeking@Red54.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include "i2c-hid.h"
+#include "i2c-hid-acpi.h"
+
+static int i2c_hid_acpi_prp0001_power_up(struct i2chid_ops *ops)
+{
+	/* give the device time to power up */
+	msleep(250);
+	return 0;
+}
+
+static struct i2chid_ops i2c_hid_acpi_prp0001_ops = {
+	.power_up = i2c_hid_acpi_prp0001_power_up,
+	/*
+	 * No .restore_sequence needed: the _DSM on these devices returns a
+	 * constant (0x20) with no side effects, unlike some PNP0C50 _DSM
+	 * implementations that switch the hardware between PS/2 and I2C modes.
+	 */
+};
+
+static int i2c_hid_acpi_prp0001_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct acpi_device *adev;
+	u16 hid_descriptor_address;
+	int ret;
+
+	/* If hid-descr-addr is present, let i2c-hid-of handle it */
+	if (device_property_present(dev, "hid-descr-addr"))
+		return -ENODEV;
+
+	adev = ACPI_COMPANION(dev);
+	if (!adev)
+		return -ENODEV;
+
+	ret = i2c_hid_acpi_get_descriptor(adev);
+	if (ret < 0)
+		return ret;
+	hid_descriptor_address = ret;
+
+	/*
+	 * No acpi_device_fix_up_power() needed: TPD0 has no _PS0, _PS3, _PSC
+	 * or _PRx methods and follows I2C bus power.
+	 */
+	return i2c_hid_core_probe(client, &i2c_hid_acpi_prp0001_ops,
+				  hid_descriptor_address, 0);
+}
+
+static const struct of_device_id i2c_hid_acpi_prp0001_of_match[] = {
+	{ .compatible = "hid-over-i2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, i2c_hid_acpi_prp0001_of_match);
+
+static const struct i2c_device_id i2c_hid_acpi_prp0001_id[] = {
+	{ .name = "hid-over-i2c" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, i2c_hid_acpi_prp0001_id);
+
+static struct i2c_driver i2c_hid_acpi_prp0001_driver = {
+	.driver = {
+		.name	= "i2c_hid_acpi_prp0001",
+		.pm	= &i2c_hid_core_pm,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = of_match_ptr(i2c_hid_acpi_prp0001_of_match),
+	},
+
+	.probe		= i2c_hid_acpi_prp0001_probe,
+	.remove		= i2c_hid_core_remove,
+	.shutdown	= i2c_hid_core_shutdown,
+	.id_table	= i2c_hid_acpi_prp0001_id,
+};
+
+module_i2c_driver(i2c_hid_acpi_prp0001_driver);
+
+MODULE_DESCRIPTION("HID over I2C driver for PRP0001 devices missing hid-descr-addr");
+MODULE_AUTHOR("谢致邦 (XIE Zhibang) <Yeking@Red54.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.c b/drivers/hid/i2c-hid/i2c-hid-acpi.c
index abd700a101f4..f0bcfb2663ef 100644
--- a/drivers/hid/i2c-hid/i2c-hid-acpi.c
+++ b/drivers/hid/i2c-hid/i2c-hid-acpi.c
@@ -25,9 +25,9 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pm.h>
-#include <linux/uuid.h>
 
 #include "i2c-hid.h"
+#include "i2c-hid-acpi.h"
 
 struct i2c_hid_acpi {
 	struct i2chid_ops ops;
@@ -48,39 +48,11 @@ static const struct acpi_device_id i2c_hid_acpi_blacklist[] = {
 	{ }
 };
 
-/* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
-static guid_t i2c_hid_guid =
-	GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
-		  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
-
-static int i2c_hid_acpi_get_descriptor(struct i2c_hid_acpi *ihid_acpi)
-{
-	struct acpi_device *adev = ihid_acpi->adev;
-	acpi_handle handle = acpi_device_handle(adev);
-	union acpi_object *obj;
-	u16 hid_descriptor_address;
-
-	if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
-		return -ENODEV;
-
-	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL,
-				      ACPI_TYPE_INTEGER);
-	if (!obj) {
-		acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n");
-		return -ENODEV;
-	}
-
-	hid_descriptor_address = obj->integer.value;
-	ACPI_FREE(obj);
-
-	return hid_descriptor_address;
-}
-
 static void i2c_hid_acpi_restore_sequence(struct i2chid_ops *ops)
 {
 	struct i2c_hid_acpi *ihid_acpi = container_of(ops, struct i2c_hid_acpi, ops);
 
-	i2c_hid_acpi_get_descriptor(ihid_acpi);
+	i2c_hid_acpi_get_descriptor(ihid_acpi->adev);
 }
 
 static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
@@ -93,23 +65,27 @@ static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
 static int i2c_hid_acpi_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 	struct i2c_hid_acpi *ihid_acpi;
 	u16 hid_descriptor_address;
 	int ret;
 
+	if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
+		return -ENODEV;
+
+	ret = i2c_hid_acpi_get_descriptor(adev);
+	if (ret < 0)
+		return ret;
+	hid_descriptor_address = ret;
+
 	ihid_acpi = devm_kzalloc(&client->dev, sizeof(*ihid_acpi), GFP_KERNEL);
 	if (!ihid_acpi)
 		return -ENOMEM;
 
-	ihid_acpi->adev = ACPI_COMPANION(dev);
+	ihid_acpi->adev = adev;
 	ihid_acpi->ops.shutdown_tail = i2c_hid_acpi_shutdown_tail;
 	ihid_acpi->ops.restore_sequence = i2c_hid_acpi_restore_sequence;
 
-	ret = i2c_hid_acpi_get_descriptor(ihid_acpi);
-	if (ret < 0)
-		return ret;
-	hid_descriptor_address = ret;
-
 	acpi_device_fix_up_power(ihid_acpi->adev);
 
 	return i2c_hid_core_probe(client, &ihid_acpi->ops,
diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.h b/drivers/hid/i2c-hid/i2c-hid-acpi.h
new file mode 100644
index 000000000000..8cebbeebcc23
--- /dev/null
+++ b/drivers/hid/i2c-hid/i2c-hid-acpi.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _I2C_HID_ACPI_H
+#define _I2C_HID_ACPI_H
+
+#include <linux/acpi.h>
+#include <linux/uuid.h>
+
+static inline int i2c_hid_acpi_get_descriptor(struct acpi_device *adev)
+{
+	/* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
+	static const guid_t i2c_hid_guid =
+		GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
+			  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
+
+	acpi_handle handle = acpi_device_handle(adev);
+	union acpi_object *obj;
+	u16 addr;
+
+	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid,
+				      1, 1, NULL, ACPI_TYPE_INTEGER);
+	if (!obj) {
+		acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n");
+		return -ENODEV;
+	}
+
+	addr = obj->integer.value;
+	ACPI_FREE(obj);
+	return addr;
+}
+
+#endif
-- 
2.54.0

[PATCH v3] HID: i2c-hid: Refactor _DSM helper and add i2c-hid-acpi-prp0001 driver

[谢致邦 (XIE Zhibang)]

Move the _DSM call that gets the HID descriptor address from
i2c-hid-acpi.c into i2c-hid-acpi.h as a static inline so both the ACPI
and the new PRP0001 driver can use it. While refactoring, move the
blacklist check and the _DSM call to the top of probe() to avoid a
pointless alloc when the device is blacklisted or does not implement the
_DSM.

Some devices, for example the Lenovo KaiTian N60d and Inspur CP300L3,
are declared with _HID "PRP0001" and _DSD compatible "hid-over-i2c" but
lack "hid-descr-addr" from the _DSD and provide the HID descriptor
address only through an ACPI _DSM. The OF driver fails to probe them
because it requires hid-descr-addr. Add a new driver that handles these
devices by calling the shared _DSM helper.

Fixes: b33752c30023 ("HID: i2c-hid: Reorganize so ACPI and OF are separate modules")
Signed-off-by: 谢致邦 (XIE Zhibang) <Yeking@Red54.com>
---
v2: Name the unused parameter and document why
acpi_device_fix_up_power() is skipped.
v3: Add a dev_warn() asking users to contact vendors for firmware
updates, and use existing locals in devm_kzalloc() and
acpi_device_fix_up_power().

 drivers/hid/i2c-hid/Kconfig                | 18 ++++
 drivers/hid/i2c-hid/Makefile               |  1 +
 drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c | 98 ++++++++++++++++++++++
 drivers/hid/i2c-hid/i2c-hid-acpi.c         | 52 ++++--------
 drivers/hid/i2c-hid/i2c-hid-acpi.h         | 32 +++++++
 5 files changed, 163 insertions(+), 38 deletions(-)
 create mode 100644 drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
 create mode 100644 drivers/hid/i2c-hid/i2c-hid-acpi.h

diff --git a/drivers/hid/i2c-hid/Kconfig b/drivers/hid/i2c-hid/Kconfig
index e8d51f410cc1..7db8b2abff78 100644
--- a/drivers/hid/i2c-hid/Kconfig
+++ b/drivers/hid/i2c-hid/Kconfig
@@ -22,6 +22,24 @@ config I2C_HID_ACPI
 	  will be called i2c-hid-acpi.  It will also build/depend on the
 	  module i2c-hid.
 
+config I2C_HID_ACPI_PRP0001
+	tristate "Driver for PRP0001 devices missing hid-descr-addr"
+	depends on ACPI
+	depends on DRM || !DRM
+	select I2C_HID_CORE
+	help
+	  Say Y here if you want support for I2C HID touchpads that
+	  are declared with _HID "PRP0001" and _DSD compatible
+	  "hid-over-i2c" but lack the "hid-descr-addr" property from
+	  the _DSD. The HID descriptor address is instead provided
+	  through an ACPI _DSM. Known affected devices include the
+	  Lenovo KaiTian N60d and Inspur CP300L3.
+
+	  If unsure, say N.
+
+	  This support is also available as a module. If so, the
+	  module will be called i2c-hid-acpi-prp0001.
+
 config I2C_HID_OF
 	tristate "HID over I2C transport layer Open Firmware driver"
 	# No "depends on OF" because this can also be used for manually
diff --git a/drivers/hid/i2c-hid/Makefile b/drivers/hid/i2c-hid/Makefile
index 55bd5e0f35af..da420c1a8ec6 100644
--- a/drivers/hid/i2c-hid/Makefile
+++ b/drivers/hid/i2c-hid/Makefile
@@ -9,6 +9,7 @@ i2c-hid-objs					=  i2c-hid-core.o
 i2c-hid-$(CONFIG_DMI)				+= i2c-hid-dmi-quirks.o
 
 obj-$(CONFIG_I2C_HID_ACPI)			+= i2c-hid-acpi.o
+obj-$(CONFIG_I2C_HID_ACPI_PRP0001)		+= i2c-hid-acpi-prp0001.o
 obj-$(CONFIG_I2C_HID_OF)			+= i2c-hid-of.o
 obj-$(CONFIG_I2C_HID_OF_ELAN)			+= i2c-hid-of-elan.o
 obj-$(CONFIG_I2C_HID_OF_GOODIX)			+= i2c-hid-of-goodix.o
diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c b/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
new file mode 100644
index 000000000000..b54370a938ab
--- /dev/null
+++ b/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * HID over I2C driver for PRP0001 devices missing hid-descr-addr
+ *
+ * Some devices, for example the Lenovo KaiTian N60d and Inspur CP300L3, use
+ * _HID "PRP0001" with _DSD compatible "hid-over-i2c" but lack "hid-descr-addr"
+ * from the _DSD. The HID descriptor address is provided only through an ACPI
+ * _DSM. The TPD0 node in the DSDT shows _DSM Function 1 returning 0x20.
+ *
+ * Copyright (C) 2026 谢致邦 (XIE Zhibang) <Yeking@Red54.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include "i2c-hid.h"
+#include "i2c-hid-acpi.h"
+
+static int i2c_hid_acpi_prp0001_power_up(struct i2chid_ops *ops)
+{
+	/* give the device time to power up */
+	msleep(250);
+	return 0;
+}
+
+static struct i2chid_ops i2c_hid_acpi_prp0001_ops = {
+	.power_up = i2c_hid_acpi_prp0001_power_up,
+	/*
+	 * No .restore_sequence needed: the _DSM on these devices returns a
+	 * constant (0x20) with no side effects, unlike some PNP0C50 _DSM
+	 * implementations that switch the hardware between PS/2 and I2C modes.
+	 */
+};
+
+static int i2c_hid_acpi_prp0001_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct acpi_device *adev;
+	u16 hid_descriptor_address;
+	int ret;
+
+	/* If hid-descr-addr is present, let i2c-hid-of handle it */
+	if (device_property_present(dev, "hid-descr-addr"))
+		return -ENODEV;
+
+	adev = ACPI_COMPANION(dev);
+	if (!adev)
+		return -ENODEV;
+
+	ret = i2c_hid_acpi_get_descriptor(adev);
+	if (ret < 0)
+		return ret;
+	dev_warn(dev,
+		 "hid-descr-addr device property NOT found, using ACPI _DSM fallback. Contact vendor for firmware update!\n");
+	hid_descriptor_address = ret;
+
+	/*
+	 * No acpi_device_fix_up_power() needed: TPD0 has no _PS0, _PS3, _PSC
+	 * or _PRx methods and follows I2C bus power.
+	 */
+	return i2c_hid_core_probe(client, &i2c_hid_acpi_prp0001_ops,
+				  hid_descriptor_address, 0);
+}
+
+static const struct of_device_id i2c_hid_acpi_prp0001_of_match[] = {
+	{ .compatible = "hid-over-i2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, i2c_hid_acpi_prp0001_of_match);
+
+static const struct i2c_device_id i2c_hid_acpi_prp0001_id[] = {
+	{ .name = "hid-over-i2c" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, i2c_hid_acpi_prp0001_id);
+
+static struct i2c_driver i2c_hid_acpi_prp0001_driver = {
+	.driver = {
+		.name	= "i2c_hid_acpi_prp0001",
+		.pm	= &i2c_hid_core_pm,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = of_match_ptr(i2c_hid_acpi_prp0001_of_match),
+	},
+
+	.probe		= i2c_hid_acpi_prp0001_probe,
+	.remove		= i2c_hid_core_remove,
+	.shutdown	= i2c_hid_core_shutdown,
+	.id_table	= i2c_hid_acpi_prp0001_id,
+};
+
+module_i2c_driver(i2c_hid_acpi_prp0001_driver);
+
+MODULE_DESCRIPTION("HID over I2C driver for PRP0001 devices missing hid-descr-addr");
+MODULE_AUTHOR("谢致邦 (XIE Zhibang) <Yeking@Red54.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.c b/drivers/hid/i2c-hid/i2c-hid-acpi.c
index abd700a101f4..13f977d6aab6 100644
--- a/drivers/hid/i2c-hid/i2c-hid-acpi.c
+++ b/drivers/hid/i2c-hid/i2c-hid-acpi.c
@@ -25,9 +25,9 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pm.h>
-#include <linux/uuid.h>
 
 #include "i2c-hid.h"
+#include "i2c-hid-acpi.h"
 
 struct i2c_hid_acpi {
 	struct i2chid_ops ops;
@@ -48,39 +48,11 @@ static const struct acpi_device_id i2c_hid_acpi_blacklist[] = {
 	{ }
 };
 
-/* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
-static guid_t i2c_hid_guid =
-	GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
-		  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
-
-static int i2c_hid_acpi_get_descriptor(struct i2c_hid_acpi *ihid_acpi)
-{
-	struct acpi_device *adev = ihid_acpi->adev;
-	acpi_handle handle = acpi_device_handle(adev);
-	union acpi_object *obj;
-	u16 hid_descriptor_address;
-
-	if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
-		return -ENODEV;
-
-	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL,
-				      ACPI_TYPE_INTEGER);
-	if (!obj) {
-		acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n");
-		return -ENODEV;
-	}
-
-	hid_descriptor_address = obj->integer.value;
-	ACPI_FREE(obj);
-
-	return hid_descriptor_address;
-}
-
 static void i2c_hid_acpi_restore_sequence(struct i2chid_ops *ops)
 {
 	struct i2c_hid_acpi *ihid_acpi = container_of(ops, struct i2c_hid_acpi, ops);
 
-	i2c_hid_acpi_get_descriptor(ihid_acpi);
+	i2c_hid_acpi_get_descriptor(ihid_acpi->adev);
 }
 
 static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
@@ -93,24 +65,28 @@ static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
 static int i2c_hid_acpi_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 	struct i2c_hid_acpi *ihid_acpi;
 	u16 hid_descriptor_address;
 	int ret;
 
-	ihid_acpi = devm_kzalloc(&client->dev, sizeof(*ihid_acpi), GFP_KERNEL);
+	if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
+		return -ENODEV;
+
+	ret = i2c_hid_acpi_get_descriptor(adev);
+	if (ret < 0)
+		return ret;
+	hid_descriptor_address = ret;
+
+	ihid_acpi = devm_kzalloc(dev, sizeof(*ihid_acpi), GFP_KERNEL);
 	if (!ihid_acpi)
 		return -ENOMEM;
 
-	ihid_acpi->adev = ACPI_COMPANION(dev);
+	ihid_acpi->adev = adev;
 	ihid_acpi->ops.shutdown_tail = i2c_hid_acpi_shutdown_tail;
 	ihid_acpi->ops.restore_sequence = i2c_hid_acpi_restore_sequence;
 
-	ret = i2c_hid_acpi_get_descriptor(ihid_acpi);
-	if (ret < 0)
-		return ret;
-	hid_descriptor_address = ret;
-
-	acpi_device_fix_up_power(ihid_acpi->adev);
+	acpi_device_fix_up_power(adev);
 
 	return i2c_hid_core_probe(client, &ihid_acpi->ops,
 				  hid_descriptor_address, 0);
diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.h b/drivers/hid/i2c-hid/i2c-hid-acpi.h
new file mode 100644
index 000000000000..8cebbeebcc23
--- /dev/null
+++ b/drivers/hid/i2c-hid/i2c-hid-acpi.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _I2C_HID_ACPI_H
+#define _I2C_HID_ACPI_H
+
+#include <linux/acpi.h>
+#include <linux/uuid.h>
+
+static inline int i2c_hid_acpi_get_descriptor(struct acpi_device *adev)
+{
+	/* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
+	static const guid_t i2c_hid_guid =
+		GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
+			  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
+
+	acpi_handle handle = acpi_device_handle(adev);
+	union acpi_object *obj;
+	u16 addr;
+
+	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid,
+				      1, 1, NULL, ACPI_TYPE_INTEGER);
+	if (!obj) {
+		acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n");
+		return -ENODEV;
+	}
+
+	addr = obj->integer.value;
+	ACPI_FREE(obj);
+	return addr;
+}
+
+#endif
-- 
2.54.0

Re: [PATCH v3] HID: i2c-hid: Refactor _DSM helper and add i2c-hid-acpi-prp0001 driver

[Hans de Goede]

Hi,

On 6-Jun-26 6:06 PM, 谢致邦 (XIE Zhibang) wrote:
> Move the _DSM call that gets the HID descriptor address from
> i2c-hid-acpi.c into i2c-hid-acpi.h as a static inline so both the ACPI
> and the new PRP0001 driver can use it. While refactoring, move the
> blacklist check and the _DSM call to the top of probe() to avoid a
> pointless alloc when the device is blacklisted or does not implement the
> _DSM.
> 
> Some devices, for example the Lenovo KaiTian N60d and Inspur CP300L3,
> are declared with _HID "PRP0001" and _DSD compatible "hid-over-i2c" but
> lack "hid-descr-addr" from the _DSD and provide the HID descriptor
> address only through an ACPI _DSM. The OF driver fails to probe them
> because it requires hid-descr-addr. Add a new driver that handles these
> devices by calling the shared _DSM helper.
> 
> Fixes: b33752c30023 ("HID: i2c-hid: Reorganize so ACPI and OF are separate modules")
> Signed-off-by: 谢致邦 (XIE Zhibang) <Yeking@Red54.com>

Thank you for the new version.

> ---
> v2: Name the unused parameter and document why
> acpi_device_fix_up_power() is skipped.
> v3: Add a dev_warn() asking users to contact vendors for firmware
> updates, and use existing locals in devm_kzalloc() and
> acpi_device_fix_up_power().
> 
>  drivers/hid/i2c-hid/Kconfig                | 18 ++++
>  drivers/hid/i2c-hid/Makefile               |  1 +
>  drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c | 98 ++++++++++++++++++++++
>  drivers/hid/i2c-hid/i2c-hid-acpi.c         | 52 ++++--------
>  drivers/hid/i2c-hid/i2c-hid-acpi.h         | 32 +++++++
>  5 files changed, 163 insertions(+), 38 deletions(-)
>  create mode 100644 drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
>  create mode 100644 drivers/hid/i2c-hid/i2c-hid-acpi.h
> 
> diff --git a/drivers/hid/i2c-hid/Kconfig b/drivers/hid/i2c-hid/Kconfig
> index e8d51f410cc1..7db8b2abff78 100644
> --- a/drivers/hid/i2c-hid/Kconfig
> +++ b/drivers/hid/i2c-hid/Kconfig
> @@ -22,6 +22,24 @@ config I2C_HID_ACPI
>  	  will be called i2c-hid-acpi.  It will also build/depend on the
>  	  module i2c-hid.
>  
> +config I2C_HID_ACPI_PRP0001
> +	tristate "Driver for PRP0001 devices missing hid-descr-addr"
> +	depends on ACPI
> +	depends on DRM || !DRM
> +	select I2C_HID_CORE
> +	help
> +	  Say Y here if you want support for I2C HID touchpads that
> +	  are declared with _HID "PRP0001" and _DSD compatible
> +	  "hid-over-i2c" but lack the "hid-descr-addr" property from
> +	  the _DSD. The HID descriptor address is instead provided
> +	  through an ACPI _DSM. Known affected devices include the
> +	  Lenovo KaiTian N60d and Inspur CP300L3.
> +
> +	  If unsure, say N.
> +
> +	  This support is also available as a module. If so, the
> +	  module will be called i2c-hid-acpi-prp0001.
> +
>  config I2C_HID_OF
>  	tristate "HID over I2C transport layer Open Firmware driver"
>  	# No "depends on OF" because this can also be used for manually
> diff --git a/drivers/hid/i2c-hid/Makefile b/drivers/hid/i2c-hid/Makefile
> index 55bd5e0f35af..da420c1a8ec6 100644
> --- a/drivers/hid/i2c-hid/Makefile
> +++ b/drivers/hid/i2c-hid/Makefile
> @@ -9,6 +9,7 @@ i2c-hid-objs					=  i2c-hid-core.o
>  i2c-hid-$(CONFIG_DMI)				+= i2c-hid-dmi-quirks.o
>  
>  obj-$(CONFIG_I2C_HID_ACPI)			+= i2c-hid-acpi.o
> +obj-$(CONFIG_I2C_HID_ACPI_PRP0001)		+= i2c-hid-acpi-prp0001.o
>  obj-$(CONFIG_I2C_HID_OF)			+= i2c-hid-of.o
>  obj-$(CONFIG_I2C_HID_OF_ELAN)			+= i2c-hid-of-elan.o
>  obj-$(CONFIG_I2C_HID_OF_GOODIX)			+= i2c-hid-of-goodix.o
> diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c b/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
> new file mode 100644
> index 000000000000..b54370a938ab
> --- /dev/null
> +++ b/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
> @@ -0,0 +1,98 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * HID over I2C driver for PRP0001 devices missing hid-descr-addr
> + *
> + * Some devices, for example the Lenovo KaiTian N60d and Inspur CP300L3, use
> + * _HID "PRP0001" with _DSD compatible "hid-over-i2c" but lack "hid-descr-addr"
> + * from the _DSD. The HID descriptor address is provided only through an ACPI
> + * _DSM. The TPD0 node in the DSDT shows _DSM Function 1 returning 0x20.
> + *
> + * Copyright (C) 2026 谢致邦 (XIE Zhibang) <Yeking@Red54.com>
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +
> +#include "i2c-hid.h"
> +#include "i2c-hid-acpi.h"
> +
> +static int i2c_hid_acpi_prp0001_power_up(struct i2chid_ops *ops)
> +{
> +	/* give the device time to power up */
> +	msleep(250);
> +	return 0;
> +}
> +
> +static struct i2chid_ops i2c_hid_acpi_prp0001_ops = {
> +	.power_up = i2c_hid_acpi_prp0001_power_up,
> +	/*
> +	 * No .restore_sequence needed: the _DSM on these devices returns a
> +	 * constant (0x20) with no side effects, unlike some PNP0C50 _DSM
> +	 * implementations that switch the hardware between PS/2 and I2C modes.
> +	 */
> +};
> +
> +static int i2c_hid_acpi_prp0001_probe(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct acpi_device *adev;
> +	u16 hid_descriptor_address;
> +	int ret;
> +
> +	/* If hid-descr-addr is present, let i2c-hid-of handle it */
> +	if (device_property_present(dev, "hid-descr-addr"))
> +		return -ENODEV;
> +
> +	adev = ACPI_COMPANION(dev);
> +	if (!adev)
> +		return -ENODEV;
> +
> +	ret = i2c_hid_acpi_get_descriptor(adev);
> +	if (ret < 0)
> +		return ret;
> +	dev_warn(dev,
> +		 "hid-descr-addr device property NOT found, using ACPI _DSM fallback. Contact vendor for firmware update!\n");
> +	hid_descriptor_address = ret;
> +
> +	/*
> +	 * No acpi_device_fix_up_power() needed: TPD0 has no _PS0, _PS3, _PSC
> +	 * or _PRx methods and follows I2C bus power.
> +	 */
> +	return i2c_hid_core_probe(client, &i2c_hid_acpi_prp0001_ops,
> +				  hid_descriptor_address, 0);
> +}
> +
> +static const struct of_device_id i2c_hid_acpi_prp0001_of_match[] = {
> +	{ .compatible = "hid-over-i2c" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, i2c_hid_acpi_prp0001_of_match);
> +
> +static const struct i2c_device_id i2c_hid_acpi_prp0001_id[] = {
> +	{ .name = "hid-over-i2c" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, i2c_hid_acpi_prp0001_id);
> +
> +static struct i2c_driver i2c_hid_acpi_prp0001_driver = {
> +	.driver = {
> +		.name	= "i2c_hid_acpi_prp0001",
> +		.pm	= &i2c_hid_core_pm,
> +		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
> +		.of_match_table = of_match_ptr(i2c_hid_acpi_prp0001_of_match),
> +	},
> +
> +	.probe		= i2c_hid_acpi_prp0001_probe,
> +	.remove		= i2c_hid_core_remove,
> +	.shutdown	= i2c_hid_core_shutdown,
> +	.id_table	= i2c_hid_acpi_prp0001_id,
> +};
> +
> +module_i2c_driver(i2c_hid_acpi_prp0001_driver);
> +
> +MODULE_DESCRIPTION("HID over I2C driver for PRP0001 devices missing hid-descr-addr");
> +MODULE_AUTHOR("谢致邦 (XIE Zhibang) <Yeking@Red54.com>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.c b/drivers/hid/i2c-hid/i2c-hid-acpi.c
> index abd700a101f4..13f977d6aab6 100644
> --- a/drivers/hid/i2c-hid/i2c-hid-acpi.c
> +++ b/drivers/hid/i2c-hid/i2c-hid-acpi.c
> @@ -25,9 +25,9 @@
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/pm.h>
> -#include <linux/uuid.h>
>  
>  #include "i2c-hid.h"
> +#include "i2c-hid-acpi.h"
>  
>  struct i2c_hid_acpi {
>  	struct i2chid_ops ops;
> @@ -48,39 +48,11 @@ static const struct acpi_device_id i2c_hid_acpi_blacklist[] = {
>  	{ }
>  };
>  
> -/* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
> -static guid_t i2c_hid_guid =
> -	GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
> -		  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
> -
> -static int i2c_hid_acpi_get_descriptor(struct i2c_hid_acpi *ihid_acpi)
> -{
> -	struct acpi_device *adev = ihid_acpi->adev;
> -	acpi_handle handle = acpi_device_handle(adev);
> -	union acpi_object *obj;
> -	u16 hid_descriptor_address;
> -
> -	if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
> -		return -ENODEV;
> -
> -	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL,
> -				      ACPI_TYPE_INTEGER);
> -	if (!obj) {
> -		acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n");
> -		return -ENODEV;
> -	}
> -
> -	hid_descriptor_address = obj->integer.value;
> -	ACPI_FREE(obj);
> -
> -	return hid_descriptor_address;
> -}
> -

Instead of moving this to i2c-hid-acpi.h, please make it non static an
export it using EXPORT_SYMBOL_GPL() and only put a prototype in i2c-hid-acpi.h .

The change to make it take an acpi_device pointer instead of i2c_hid_acpi *ihid_acpi
should be kept, but without moving the function to the .h file.

Regards,

Hans



>  static void i2c_hid_acpi_restore_sequence(struct i2chid_ops *ops)
>  {
>  	struct i2c_hid_acpi *ihid_acpi = container_of(ops, struct i2c_hid_acpi, ops);
>  
> -	i2c_hid_acpi_get_descriptor(ihid_acpi);
> +	i2c_hid_acpi_get_descriptor(ihid_acpi->adev);
>  }
>  
>  static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
> @@ -93,24 +65,28 @@ static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
>  static int i2c_hid_acpi_probe(struct i2c_client *client)
>  {
>  	struct device *dev = &client->dev;
> +	struct acpi_device *adev = ACPI_COMPANION(dev);
>  	struct i2c_hid_acpi *ihid_acpi;
>  	u16 hid_descriptor_address;
>  	int ret;
>  
> -	ihid_acpi = devm_kzalloc(&client->dev, sizeof(*ihid_acpi), GFP_KERNEL);
> +	if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
> +		return -ENODEV;
> +
> +	ret = i2c_hid_acpi_get_descriptor(adev);
> +	if (ret < 0)
> +		return ret;
> +	hid_descriptor_address = ret;
> +
> +	ihid_acpi = devm_kzalloc(dev, sizeof(*ihid_acpi), GFP_KERNEL);
>  	if (!ihid_acpi)
>  		return -ENOMEM;
>  
> -	ihid_acpi->adev = ACPI_COMPANION(dev);
> +	ihid_acpi->adev = adev;
>  	ihid_acpi->ops.shutdown_tail = i2c_hid_acpi_shutdown_tail;
>  	ihid_acpi->ops.restore_sequence = i2c_hid_acpi_restore_sequence;
>  
> -	ret = i2c_hid_acpi_get_descriptor(ihid_acpi);
> -	if (ret < 0)
> -		return ret;
> -	hid_descriptor_address = ret;
> -
> -	acpi_device_fix_up_power(ihid_acpi->adev);
> +	acpi_device_fix_up_power(adev);
>  
>  	return i2c_hid_core_probe(client, &ihid_acpi->ops,
>  				  hid_descriptor_address, 0);
> diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.h b/drivers/hid/i2c-hid/i2c-hid-acpi.h
> new file mode 100644
> index 000000000000..8cebbeebcc23
> --- /dev/null
> +++ b/drivers/hid/i2c-hid/i2c-hid-acpi.h
> @@ -0,0 +1,32 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#ifndef _I2C_HID_ACPI_H
> +#define _I2C_HID_ACPI_H
> +
> +#include <linux/acpi.h>
> +#include <linux/uuid.h>
> +
> +static inline int i2c_hid_acpi_get_descriptor(struct acpi_device *adev)
> +{
> +	/* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
> +	static const guid_t i2c_hid_guid =
> +		GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
> +			  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
> +
> +	acpi_handle handle = acpi_device_handle(adev);
> +	union acpi_object *obj;
> +	u16 addr;
> +
> +	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid,
> +				      1, 1, NULL, ACPI_TYPE_INTEGER);
> +	if (!obj) {
> +		acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n");
> +		return -ENODEV;
> +	}
> +
> +	addr = obj->integer.value;
> +	ACPI_FREE(obj);
> +	return addr;
> +}
> +
> +#endif

Re: [PATCH v3] HID: i2c-hid: Refactor _DSM helper and add i2c-hid-acpi-prp0001 driver

[Hans de Goede]

Hi,

On 8-Jun-26 1:48 PM, Hans de Goede wrote:
> Hi,
> 
> On 6-Jun-26 6:06 PM, 谢致邦 (XIE Zhibang) wrote:
>> Move the _DSM call that gets the HID descriptor address from
>> i2c-hid-acpi.c into i2c-hid-acpi.h as a static inline so both the ACPI
>> and the new PRP0001 driver can use it. While refactoring, move the
>> blacklist check and the _DSM call to the top of probe() to avoid a
>> pointless alloc when the device is blacklisted or does not implement the
>> _DSM.
>>
>> Some devices, for example the Lenovo KaiTian N60d and Inspur CP300L3,
>> are declared with _HID "PRP0001" and _DSD compatible "hid-over-i2c" but
>> lack "hid-descr-addr" from the _DSD and provide the HID descriptor
>> address only through an ACPI _DSM. The OF driver fails to probe them
>> because it requires hid-descr-addr. Add a new driver that handles these
>> devices by calling the shared _DSM helper.
>>
>> Fixes: b33752c30023 ("HID: i2c-hid: Reorganize so ACPI and OF are separate modules")
>> Signed-off-by: 谢致邦 (XIE Zhibang) <Yeking@Red54.com>
> 
> Thank you for the new version.
> 
>> ---
>> v2: Name the unused parameter and document why
>> acpi_device_fix_up_power() is skipped.
>> v3: Add a dev_warn() asking users to contact vendors for firmware
>> updates, and use existing locals in devm_kzalloc() and
>> acpi_device_fix_up_power().
>>
>>  drivers/hid/i2c-hid/Kconfig                | 18 ++++
>>  drivers/hid/i2c-hid/Makefile               |  1 +
>>  drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c | 98 ++++++++++++++++++++++
>>  drivers/hid/i2c-hid/i2c-hid-acpi.c         | 52 ++++--------
>>  drivers/hid/i2c-hid/i2c-hid-acpi.h         | 32 +++++++
>>  5 files changed, 163 insertions(+), 38 deletions(-)
>>  create mode 100644 drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
>>  create mode 100644 drivers/hid/i2c-hid/i2c-hid-acpi.h
>>
>> diff --git a/drivers/hid/i2c-hid/Kconfig b/drivers/hid/i2c-hid/Kconfig
>> index e8d51f410cc1..7db8b2abff78 100644
>> --- a/drivers/hid/i2c-hid/Kconfig
>> +++ b/drivers/hid/i2c-hid/Kconfig
>> @@ -22,6 +22,24 @@ config I2C_HID_ACPI
>>  	  will be called i2c-hid-acpi.  It will also build/depend on the
>>  	  module i2c-hid.
>>  
>> +config I2C_HID_ACPI_PRP0001
>> +	tristate "Driver for PRP0001 devices missing hid-descr-addr"
>> +	depends on ACPI
>> +	depends on DRM || !DRM
>> +	select I2C_HID_CORE
>> +	help
>> +	  Say Y here if you want support for I2C HID touchpads that
>> +	  are declared with _HID "PRP0001" and _DSD compatible
>> +	  "hid-over-i2c" but lack the "hid-descr-addr" property from
>> +	  the _DSD. The HID descriptor address is instead provided
>> +	  through an ACPI _DSM. Known affected devices include the
>> +	  Lenovo KaiTian N60d and Inspur CP300L3.
>> +
>> +	  If unsure, say N.
>> +
>> +	  This support is also available as a module. If so, the
>> +	  module will be called i2c-hid-acpi-prp0001.
>> +
>>  config I2C_HID_OF
>>  	tristate "HID over I2C transport layer Open Firmware driver"
>>  	# No "depends on OF" because this can also be used for manually
>> diff --git a/drivers/hid/i2c-hid/Makefile b/drivers/hid/i2c-hid/Makefile
>> index 55bd5e0f35af..da420c1a8ec6 100644
>> --- a/drivers/hid/i2c-hid/Makefile
>> +++ b/drivers/hid/i2c-hid/Makefile
>> @@ -9,6 +9,7 @@ i2c-hid-objs					=  i2c-hid-core.o
>>  i2c-hid-$(CONFIG_DMI)				+= i2c-hid-dmi-quirks.o
>>  
>>  obj-$(CONFIG_I2C_HID_ACPI)			+= i2c-hid-acpi.o
>> +obj-$(CONFIG_I2C_HID_ACPI_PRP0001)		+= i2c-hid-acpi-prp0001.o
>>  obj-$(CONFIG_I2C_HID_OF)			+= i2c-hid-of.o
>>  obj-$(CONFIG_I2C_HID_OF_ELAN)			+= i2c-hid-of-elan.o
>>  obj-$(CONFIG_I2C_HID_OF_GOODIX)			+= i2c-hid-of-goodix.o
>> diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c b/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
>> new file mode 100644
>> index 000000000000..b54370a938ab
>> --- /dev/null
>> +++ b/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
>> @@ -0,0 +1,98 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * HID over I2C driver for PRP0001 devices missing hid-descr-addr
>> + *
>> + * Some devices, for example the Lenovo KaiTian N60d and Inspur CP300L3, use
>> + * _HID "PRP0001" with _DSD compatible "hid-over-i2c" but lack "hid-descr-addr"
>> + * from the _DSD. The HID descriptor address is provided only through an ACPI
>> + * _DSM. The TPD0 node in the DSDT shows _DSM Function 1 returning 0x20.
>> + *
>> + * Copyright (C) 2026 谢致邦 (XIE Zhibang) <Yeking@Red54.com>
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/device.h>
>> +#include <linux/i2c.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +
>> +#include "i2c-hid.h"
>> +#include "i2c-hid-acpi.h"
>> +
>> +static int i2c_hid_acpi_prp0001_power_up(struct i2chid_ops *ops)
>> +{
>> +	/* give the device time to power up */
>> +	msleep(250);
>> +	return 0;
>> +}
>> +
>> +static struct i2chid_ops i2c_hid_acpi_prp0001_ops = {
>> +	.power_up = i2c_hid_acpi_prp0001_power_up,
>> +	/*
>> +	 * No .restore_sequence needed: the _DSM on these devices returns a
>> +	 * constant (0x20) with no side effects, unlike some PNP0C50 _DSM
>> +	 * implementations that switch the hardware between PS/2 and I2C modes.
>> +	 */
>> +};
>> +
>> +static int i2c_hid_acpi_prp0001_probe(struct i2c_client *client)
>> +{
>> +	struct device *dev = &client->dev;
>> +	struct acpi_device *adev;
>> +	u16 hid_descriptor_address;
>> +	int ret;
>> +
>> +	/* If hid-descr-addr is present, let i2c-hid-of handle it */
>> +	if (device_property_present(dev, "hid-descr-addr"))
>> +		return -ENODEV;
>> +
>> +	adev = ACPI_COMPANION(dev);
>> +	if (!adev)
>> +		return -ENODEV;
>> +
>> +	ret = i2c_hid_acpi_get_descriptor(adev);
>> +	if (ret < 0)
>> +		return ret;
>> +	dev_warn(dev,
>> +		 "hid-descr-addr device property NOT found, using ACPI _DSM fallback. Contact vendor for firmware update!\n");
>> +	hid_descriptor_address = ret;
>> +
>> +	/*
>> +	 * No acpi_device_fix_up_power() needed: TPD0 has no _PS0, _PS3, _PSC
>> +	 * or _PRx methods and follows I2C bus power.
>> +	 */
>> +	return i2c_hid_core_probe(client, &i2c_hid_acpi_prp0001_ops,
>> +				  hid_descriptor_address, 0);
>> +}
>> +
>> +static const struct of_device_id i2c_hid_acpi_prp0001_of_match[] = {
>> +	{ .compatible = "hid-over-i2c" },
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, i2c_hid_acpi_prp0001_of_match);
>> +
>> +static const struct i2c_device_id i2c_hid_acpi_prp0001_id[] = {
>> +	{ .name = "hid-over-i2c" },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(i2c, i2c_hid_acpi_prp0001_id);
>> +
>> +static struct i2c_driver i2c_hid_acpi_prp0001_driver = {
>> +	.driver = {
>> +		.name	= "i2c_hid_acpi_prp0001",
>> +		.pm	= &i2c_hid_core_pm,
>> +		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
>> +		.of_match_table = of_match_ptr(i2c_hid_acpi_prp0001_of_match),
>> +	},
>> +
>> +	.probe		= i2c_hid_acpi_prp0001_probe,
>> +	.remove		= i2c_hid_core_remove,
>> +	.shutdown	= i2c_hid_core_shutdown,
>> +	.id_table	= i2c_hid_acpi_prp0001_id,
>> +};
>> +
>> +module_i2c_driver(i2c_hid_acpi_prp0001_driver);
>> +
>> +MODULE_DESCRIPTION("HID over I2C driver for PRP0001 devices missing hid-descr-addr");
>> +MODULE_AUTHOR("谢致邦 (XIE Zhibang) <Yeking@Red54.com>");
>> +MODULE_LICENSE("GPL");
>> diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.c b/drivers/hid/i2c-hid/i2c-hid-acpi.c
>> index abd700a101f4..13f977d6aab6 100644
>> --- a/drivers/hid/i2c-hid/i2c-hid-acpi.c
>> +++ b/drivers/hid/i2c-hid/i2c-hid-acpi.c
>> @@ -25,9 +25,9 @@
>>  #include <linux/kernel.h>
>>  #include <linux/module.h>
>>  #include <linux/pm.h>
>> -#include <linux/uuid.h>
>>  
>>  #include "i2c-hid.h"
>> +#include "i2c-hid-acpi.h"
>>  
>>  struct i2c_hid_acpi {
>>  	struct i2chid_ops ops;
>> @@ -48,39 +48,11 @@ static const struct acpi_device_id i2c_hid_acpi_blacklist[] = {
>>  	{ }
>>  };
>>  
>> -/* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
>> -static guid_t i2c_hid_guid =
>> -	GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
>> -		  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
>> -
>> -static int i2c_hid_acpi_get_descriptor(struct i2c_hid_acpi *ihid_acpi)
>> -{
>> -	struct acpi_device *adev = ihid_acpi->adev;
>> -	acpi_handle handle = acpi_device_handle(adev);
>> -	union acpi_object *obj;
>> -	u16 hid_descriptor_address;
>> -
>> -	if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
>> -		return -ENODEV;
>> -
>> -	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL,
>> -				      ACPI_TYPE_INTEGER);
>> -	if (!obj) {
>> -		acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n");
>> -		return -ENODEV;
>> -	}
>> -
>> -	hid_descriptor_address = obj->integer.value;
>> -	ACPI_FREE(obj);
>> -
>> -	return hid_descriptor_address;
>> -}
>> -
> 
> Instead of moving this to i2c-hid-acpi.h, please make it non static an
> export it using EXPORT_SYMBOL_GPL() and only put a prototype in i2c-hid-acpi.h .

I just noticed i2c-hid-acpi.h is a whole new file. No need to add that just for
the prototype (I think / IMHO).

So for the next version just export the function from i2c-hid-acpi.c and
add a prototype declaration directly in i2c-hid-acpi-prp0001.c

Regards,
 
Hans



>>  static void i2c_hid_acpi_restore_sequence(struct i2chid_ops *ops)
>>  {
>>  	struct i2c_hid_acpi *ihid_acpi = container_of(ops, struct i2c_hid_acpi, ops);
>>  
>> -	i2c_hid_acpi_get_descriptor(ihid_acpi);
>> +	i2c_hid_acpi_get_descriptor(ihid_acpi->adev);
>>  }
>>  
>>  static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
>> @@ -93,24 +65,28 @@ static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
>>  static int i2c_hid_acpi_probe(struct i2c_client *client)
>>  {
>>  	struct device *dev = &client->dev;
>> +	struct acpi_device *adev = ACPI_COMPANION(dev);
>>  	struct i2c_hid_acpi *ihid_acpi;
>>  	u16 hid_descriptor_address;
>>  	int ret;
>>  
>> -	ihid_acpi = devm_kzalloc(&client->dev, sizeof(*ihid_acpi), GFP_KERNEL);
>> +	if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
>> +		return -ENODEV;
>> +
>> +	ret = i2c_hid_acpi_get_descriptor(adev);
>> +	if (ret < 0)
>> +		return ret;
>> +	hid_descriptor_address = ret;
>> +
>> +	ihid_acpi = devm_kzalloc(dev, sizeof(*ihid_acpi), GFP_KERNEL);
>>  	if (!ihid_acpi)
>>  		return -ENOMEM;
>>  
>> -	ihid_acpi->adev = ACPI_COMPANION(dev);
>> +	ihid_acpi->adev = adev;
>>  	ihid_acpi->ops.shutdown_tail = i2c_hid_acpi_shutdown_tail;
>>  	ihid_acpi->ops.restore_sequence = i2c_hid_acpi_restore_sequence;
>>  
>> -	ret = i2c_hid_acpi_get_descriptor(ihid_acpi);
>> -	if (ret < 0)
>> -		return ret;
>> -	hid_descriptor_address = ret;
>> -
>> -	acpi_device_fix_up_power(ihid_acpi->adev);
>> +	acpi_device_fix_up_power(adev);
>>  
>>  	return i2c_hid_core_probe(client, &ihid_acpi->ops,
>>  				  hid_descriptor_address, 0);
>> diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.h b/drivers/hid/i2c-hid/i2c-hid-acpi.h
>> new file mode 100644
>> index 000000000000..8cebbeebcc23
>> --- /dev/null
>> +++ b/drivers/hid/i2c-hid/i2c-hid-acpi.h
>> @@ -0,0 +1,32 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +
>> +#ifndef _I2C_HID_ACPI_H
>> +#define _I2C_HID_ACPI_H
>> +
>> +#include <linux/acpi.h>
>> +#include <linux/uuid.h>
>> +
>> +static inline int i2c_hid_acpi_get_descriptor(struct acpi_device *adev)
>> +{
>> +	/* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
>> +	static const guid_t i2c_hid_guid =
>> +		GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
>> +			  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
>> +
>> +	acpi_handle handle = acpi_device_handle(adev);
>> +	union acpi_object *obj;
>> +	u16 addr;
>> +
>> +	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid,
>> +				      1, 1, NULL, ACPI_TYPE_INTEGER);
>> +	if (!obj) {
>> +		acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	addr = obj->integer.value;
>> +	ACPI_FREE(obj);
>> +	return addr;
>> +}
>> +
>> +#endif
> 
> 
> 
> 

Re: [PATCH v3] HID: i2c-hid: Refactor _DSM helper and add i2c-hid-acpi-prp0001 driver

[谢致邦 (XIE Zhibang)]

Hi Hans,

Thanks for the review.

The current header-based approach lets i2c-hid-acpi-prp0001.c work
independently by just including a header for the _DSM helper. Switching
to EXPORT_SYMBOL_GPL would force prp0001 to depend on i2c-hid-acpi —
a Kconfig "depends on I2C_HID_ACPI", plus module-level dependency at
load time — all for sharing a single function. I find that hard to
accept.

I understand that adding a new header for one prototype is unusual,
though it contains only a single static inline function and introduces
no runtime dependency between the two drivers.

Looking back at the full discussion: Benjamin made it clear from the
start that he doesn't want i2c-hid-of.c handling ACPI _DSM fallback.
His line is that ACPI devices and OF devices should each go through
their own drivers without cross-contamination. If you still prefer
exporting the function from i2c-hid-acpi.c, then prp0001 would have to
drag i2c-hid-acpi along with it — an independent leaf driver turned
into something that can't stand alone.

If you still prefer the export approach, then I'd rather take a simpler
approach: add an of_match directly to
i2c-hid-acpi.c, and return -ENODEV silently at the top of probe if
hid-descr-addr is present. Same logic as the prp0001 driver, but one
fewer file, no module dependency, no extra Kconfig entry, and no OF
driver touching ACPI devices — which should also satisfy Benjamin's
concern.

Regards,
Zhibang

Re: [PATCH v3] HID: i2c-hid: Refactor _DSM helper and add i2c-hid-acpi-prp0001 driver

[谢致邦 (XIE Zhibang)]

Hi Hans,

Thanks for the review.

The current header-based approach lets i2c-hid-acpi-prp0001.c work
independently by just including a header for the _DSM helper. Switching
to EXPORT_SYMBOL_GPL would force prp0001 to depend on i2c-hid-acpi —
a Kconfig "depends on I2C_HID_ACPI", plus module-level dependency at
load time — all for sharing a single function. I find that hard to
accept.

I understand that adding a new header for one function is unusual,
though it contains only a single static inline and introduces no runtime
dependency between the two drivers.

Looking back at the full discussion: Benjamin made it clear from the
start that he doesn't want i2c-hid-of.c handling ACPI _DSM fallback.
His line is that ACPI devices and OF devices should each go through
their own drivers without cross-contamination. If you still prefer
exporting the function from i2c-hid-acpi.c, then prp0001 would have to
drag i2c-hid-acpi along with it — an independent leaf driver turned
into something that can't stand alone.

If you still prefer the export approach, then I'd rather take a simpler
approach: add an of_match directly to i2c-hid-acpi.c, and return
-ENODEV silently at the top of probe if hid-descr-addr is present. Same
logic as the prp0001 driver, but one fewer file, no module dependency,
no extra Kconfig entry, and no OF driver touching ACPI devices — which
should also satisfy Benjamin's concern.

[corrected: s/prototype/function/ — the header contains a definition,
not just a declaration]

Regards,
Zhibang

[PATCH v4] HID: i2c-hid: Refactor _DSM helper and add i2c-hid-acpi-prp0001 driver

[谢致邦 (XIE Zhibang)]

Move the _DSM call that gets the HID descriptor address from
i2c-hid-acpi.c into i2c-hid-acpi.h as a static inline so both the ACPI
and the new PRP0001 driver can use it. While refactoring, move the
blacklist check and the _DSM call to the top of probe() to avoid a
pointless alloc when the device is blacklisted or does not implement the
_DSM.

Some devices, for example the Lenovo KaiTian N60d and Inspur CP300L3,
are declared with _HID "PRP0001" and _DSD compatible "hid-over-i2c" but
lack "hid-descr-addr" from the _DSD and provide the HID descriptor
address only through an ACPI _DSM. The OF driver fails to probe them
because it requires hid-descr-addr. Add a new driver that handles these
devices by calling the shared _DSM helper.

Fixes: b33752c30023 ("HID: i2c-hid: Reorganize so ACPI and OF are separate modules")
Signed-off-by: 谢致邦 (XIE Zhibang) <Yeking@Red54.com>
---
v2: Name the unused parameter and document why
acpi_device_fix_up_power() is skipped.
v3: Add a dev_warn() asking users to contact vendors for firmware
updates, and use existing locals in devm_kzalloc() and
acpi_device_fix_up_power().
v4: Double the power-up delay from 250ms to 500ms.

 drivers/hid/i2c-hid/Kconfig                | 18 ++++
 drivers/hid/i2c-hid/Makefile               |  1 +
 drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c | 98 ++++++++++++++++++++++
 drivers/hid/i2c-hid/i2c-hid-acpi.c         | 52 ++++--------
 drivers/hid/i2c-hid/i2c-hid-acpi.h         | 32 +++++++
 5 files changed, 163 insertions(+), 38 deletions(-)
 create mode 100644 drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
 create mode 100644 drivers/hid/i2c-hid/i2c-hid-acpi.h

diff --git a/drivers/hid/i2c-hid/Kconfig b/drivers/hid/i2c-hid/Kconfig
index e8d51f410cc1..7db8b2abff78 100644
--- a/drivers/hid/i2c-hid/Kconfig
+++ b/drivers/hid/i2c-hid/Kconfig
@@ -22,6 +22,24 @@ config I2C_HID_ACPI
 	  will be called i2c-hid-acpi.  It will also build/depend on the
 	  module i2c-hid.
 
+config I2C_HID_ACPI_PRP0001
+	tristate "Driver for PRP0001 devices missing hid-descr-addr"
+	depends on ACPI
+	depends on DRM || !DRM
+	select I2C_HID_CORE
+	help
+	  Say Y here if you want support for I2C HID touchpads that
+	  are declared with _HID "PRP0001" and _DSD compatible
+	  "hid-over-i2c" but lack the "hid-descr-addr" property from
+	  the _DSD. The HID descriptor address is instead provided
+	  through an ACPI _DSM. Known affected devices include the
+	  Lenovo KaiTian N60d and Inspur CP300L3.
+
+	  If unsure, say N.
+
+	  This support is also available as a module. If so, the
+	  module will be called i2c-hid-acpi-prp0001.
+
 config I2C_HID_OF
 	tristate "HID over I2C transport layer Open Firmware driver"
 	# No "depends on OF" because this can also be used for manually
diff --git a/drivers/hid/i2c-hid/Makefile b/drivers/hid/i2c-hid/Makefile
index 55bd5e0f35af..da420c1a8ec6 100644
--- a/drivers/hid/i2c-hid/Makefile
+++ b/drivers/hid/i2c-hid/Makefile
@@ -9,6 +9,7 @@ i2c-hid-objs					=  i2c-hid-core.o
 i2c-hid-$(CONFIG_DMI)				+= i2c-hid-dmi-quirks.o
 
 obj-$(CONFIG_I2C_HID_ACPI)			+= i2c-hid-acpi.o
+obj-$(CONFIG_I2C_HID_ACPI_PRP0001)		+= i2c-hid-acpi-prp0001.o
 obj-$(CONFIG_I2C_HID_OF)			+= i2c-hid-of.o
 obj-$(CONFIG_I2C_HID_OF_ELAN)			+= i2c-hid-of-elan.o
 obj-$(CONFIG_I2C_HID_OF_GOODIX)			+= i2c-hid-of-goodix.o
diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c b/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
new file mode 100644
index 000000000000..a65830279f63
--- /dev/null
+++ b/drivers/hid/i2c-hid/i2c-hid-acpi-prp0001.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * HID over I2C driver for PRP0001 devices missing hid-descr-addr
+ *
+ * Some devices, for example the Lenovo KaiTian N60d and Inspur CP300L3, use
+ * _HID "PRP0001" with _DSD compatible "hid-over-i2c" but lack "hid-descr-addr"
+ * from the _DSD. The HID descriptor address is provided only through an ACPI
+ * _DSM. The TPD0 node in the DSDT shows _DSM Function 1 returning 0x20.
+ *
+ * Copyright (C) 2026 谢致邦 (XIE Zhibang) <Yeking@Red54.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include "i2c-hid.h"
+#include "i2c-hid-acpi.h"
+
+static int i2c_hid_acpi_prp0001_power_up(struct i2chid_ops *ops)
+{
+	/* give the device time to power up */
+	msleep(500);
+	return 0;
+}
+
+static struct i2chid_ops i2c_hid_acpi_prp0001_ops = {
+	.power_up = i2c_hid_acpi_prp0001_power_up,
+	/*
+	 * No .restore_sequence needed: the _DSM on these devices returns a
+	 * constant (0x20) with no side effects, unlike some PNP0C50 _DSM
+	 * implementations that switch the hardware between PS/2 and I2C modes.
+	 */
+};
+
+static int i2c_hid_acpi_prp0001_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct acpi_device *adev;
+	u16 hid_descriptor_address;
+	int ret;
+
+	/* If hid-descr-addr is present, let i2c-hid-of handle it */
+	if (device_property_present(dev, "hid-descr-addr"))
+		return -ENODEV;
+
+	adev = ACPI_COMPANION(dev);
+	if (!adev)
+		return -ENODEV;
+
+	ret = i2c_hid_acpi_get_descriptor(adev);
+	if (ret < 0)
+		return ret;
+	dev_warn(dev,
+		 "hid-descr-addr device property NOT found, using ACPI _DSM fallback. Contact vendor for firmware update!\n");
+	hid_descriptor_address = ret;
+
+	/*
+	 * No acpi_device_fix_up_power() needed: TPD0 has no _PS0, _PS3, _PSC
+	 * or _PRx methods and follows I2C bus power.
+	 */
+	return i2c_hid_core_probe(client, &i2c_hid_acpi_prp0001_ops,
+				  hid_descriptor_address, 0);
+}
+
+static const struct of_device_id i2c_hid_acpi_prp0001_of_match[] = {
+	{ .compatible = "hid-over-i2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, i2c_hid_acpi_prp0001_of_match);
+
+static const struct i2c_device_id i2c_hid_acpi_prp0001_id[] = {
+	{ .name = "hid-over-i2c" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, i2c_hid_acpi_prp0001_id);
+
+static struct i2c_driver i2c_hid_acpi_prp0001_driver = {
+	.driver = {
+		.name	= "i2c_hid_acpi_prp0001",
+		.pm	= &i2c_hid_core_pm,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = of_match_ptr(i2c_hid_acpi_prp0001_of_match),
+	},
+
+	.probe		= i2c_hid_acpi_prp0001_probe,
+	.remove		= i2c_hid_core_remove,
+	.shutdown	= i2c_hid_core_shutdown,
+	.id_table	= i2c_hid_acpi_prp0001_id,
+};
+
+module_i2c_driver(i2c_hid_acpi_prp0001_driver);
+
+MODULE_DESCRIPTION("HID over I2C driver for PRP0001 devices missing hid-descr-addr");
+MODULE_AUTHOR("谢致邦 (XIE Zhibang) <Yeking@Red54.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.c b/drivers/hid/i2c-hid/i2c-hid-acpi.c
index abd700a101f4..13f977d6aab6 100644
--- a/drivers/hid/i2c-hid/i2c-hid-acpi.c
+++ b/drivers/hid/i2c-hid/i2c-hid-acpi.c
@@ -25,9 +25,9 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pm.h>
-#include <linux/uuid.h>
 
 #include "i2c-hid.h"
+#include "i2c-hid-acpi.h"
 
 struct i2c_hid_acpi {
 	struct i2chid_ops ops;
@@ -48,39 +48,11 @@ static const struct acpi_device_id i2c_hid_acpi_blacklist[] = {
 	{ }
 };
 
-/* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
-static guid_t i2c_hid_guid =
-	GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
-		  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
-
-static int i2c_hid_acpi_get_descriptor(struct i2c_hid_acpi *ihid_acpi)
-{
-	struct acpi_device *adev = ihid_acpi->adev;
-	acpi_handle handle = acpi_device_handle(adev);
-	union acpi_object *obj;
-	u16 hid_descriptor_address;
-
-	if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
-		return -ENODEV;
-
-	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL,
-				      ACPI_TYPE_INTEGER);
-	if (!obj) {
-		acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n");
-		return -ENODEV;
-	}
-
-	hid_descriptor_address = obj->integer.value;
-	ACPI_FREE(obj);
-
-	return hid_descriptor_address;
-}
-
 static void i2c_hid_acpi_restore_sequence(struct i2chid_ops *ops)
 {
 	struct i2c_hid_acpi *ihid_acpi = container_of(ops, struct i2c_hid_acpi, ops);
 
-	i2c_hid_acpi_get_descriptor(ihid_acpi);
+	i2c_hid_acpi_get_descriptor(ihid_acpi->adev);
 }
 
 static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
@@ -93,24 +65,28 @@ static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
 static int i2c_hid_acpi_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 	struct i2c_hid_acpi *ihid_acpi;
 	u16 hid_descriptor_address;
 	int ret;
 
-	ihid_acpi = devm_kzalloc(&client->dev, sizeof(*ihid_acpi), GFP_KERNEL);
+	if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
+		return -ENODEV;
+
+	ret = i2c_hid_acpi_get_descriptor(adev);
+	if (ret < 0)
+		return ret;
+	hid_descriptor_address = ret;
+
+	ihid_acpi = devm_kzalloc(dev, sizeof(*ihid_acpi), GFP_KERNEL);
 	if (!ihid_acpi)
 		return -ENOMEM;
 
-	ihid_acpi->adev = ACPI_COMPANION(dev);
+	ihid_acpi->adev = adev;
 	ihid_acpi->ops.shutdown_tail = i2c_hid_acpi_shutdown_tail;
 	ihid_acpi->ops.restore_sequence = i2c_hid_acpi_restore_sequence;
 
-	ret = i2c_hid_acpi_get_descriptor(ihid_acpi);
-	if (ret < 0)
-		return ret;
-	hid_descriptor_address = ret;
-
-	acpi_device_fix_up_power(ihid_acpi->adev);
+	acpi_device_fix_up_power(adev);
 
 	return i2c_hid_core_probe(client, &ihid_acpi->ops,
 				  hid_descriptor_address, 0);
diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.h b/drivers/hid/i2c-hid/i2c-hid-acpi.h
new file mode 100644
index 000000000000..8cebbeebcc23
--- /dev/null
+++ b/drivers/hid/i2c-hid/i2c-hid-acpi.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _I2C_HID_ACPI_H
+#define _I2C_HID_ACPI_H
+
+#include <linux/acpi.h>
+#include <linux/uuid.h>
+
+static inline int i2c_hid_acpi_get_descriptor(struct acpi_device *adev)
+{
+	/* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
+	static const guid_t i2c_hid_guid =
+		GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
+			  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
+
+	acpi_handle handle = acpi_device_handle(adev);
+	union acpi_object *obj;
+	u16 addr;
+
+	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid,
+				      1, 1, NULL, ACPI_TYPE_INTEGER);
+	if (!obj) {
+		acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n");
+		return -ENODEV;
+	}
+
+	addr = obj->integer.value;
+	ACPI_FREE(obj);
+	return addr;
+}
+
+#endif
-- 
2.52.0

Re: [PATCH v3] HID: i2c-hid: Refactor _DSM helper and add i2c-hid-acpi-prp0001 driver

[Hans de Goede]

Hi,

On 9-Jun-26 12:10, 谢致邦 (XIE Zhibang) wrote:
> Hi Hans,
> 
> Thanks for the review.
> 
> The current header-based approach lets i2c-hid-acpi-prp0001.c work
> independently by just including a header for the _DSM helper. Switching
> to EXPORT_SYMBOL_GPL would force prp0001 to depend on i2c-hid-acpi —
> a Kconfig "depends on I2C_HID_ACPI", plus module-level dependency at
> load time — all for sharing a single function. I find that hard to
> accept.
> 
> I understand that adding a new header for one prototype is unusual,
> though it contains only a single static inline function and introduces
> no runtime dependency between the two drivers.
> 
> Looking back at the full discussion: Benjamin made it clear from the
> start that he doesn't want i2c-hid-of.c handling ACPI _DSM fallback.
> His line is that ACPI devices and OF devices should each go through
> their own drivers without cross-contamination. If you still prefer
> exporting the function from i2c-hid-acpi.c, then prp0001 would have to
> drag i2c-hid-acpi along with it — an independent leaf driver turned
> into something that can't stand alone.

Well it is a special case/version of the ACPI driver so depending
on it seems fine to me.

Anyways if you prefer the inline function in header solution that is
fine with me.

Lets see what bentiss has to say about this.

Regards,

Hans

Re: [PATCH v3] HID: i2c-hid: Refactor _DSM helper and add i2c-hid-acpi-prp0001 driver

[谢致邦 (XIE Zhibang)]

Hi Hans, hi Benjamin,

On Tue, Jun 09, 2026 at 03:07:53PM +0200, Hans de Goede wrote:
> Hi,
> 
> On 9-Jun-26 12:10, 谢致邦 (XIE Zhibang) wrote:
> > Hi Hans,
> > 
> > Thanks for the review.
> > 
> > The current header-based approach lets i2c-hid-acpi-prp0001.c work
> > independently by just including a header for the _DSM helper. Switching
> > to EXPORT_SYMBOL_GPL would force prp0001 to depend on i2c-hid-acpi —
> > a Kconfig "depends on I2C_HID_ACPI", plus module-level dependency at
> > load time — all for sharing a single function. I find that hard to
> > accept.
> > 
> > I understand that adding a new header for one prototype is unusual,
> > though it contains only a single static inline function and introduces
> > no runtime dependency between the two drivers.
> > 
> > Looking back at the full discussion: Benjamin made it clear from the
> > start that he doesn't want i2c-hid-of.c handling ACPI _DSM fallback.
> > His line is that ACPI devices and OF devices should each go through
> > their own drivers without cross-contamination. If you still prefer
> > exporting the function from i2c-hid-acpi.c, then prp0001 would have to
> > drag i2c-hid-acpi along with it — an independent leaf driver turned
> > into something that can't stand alone.
> 
> Well it is a special case/version of the ACPI driver so depending
> on it seems fine to me.
> 
> Anyways if you prefer the inline function in header solution that is
> fine with me.
> 
> Lets see what bentiss has to say about this.
> 
> Regards,
> 
> Hans
> 

Friendly ping — v5 was posted on Jun 12:
https://lore.kernel.org/all/tencent_8AE8ED913FEC8151B4BA3D85D6BB7F3ACF08@qq.com/

No further review comments have come in.

Is there anything else you'd like changed, or can we move forward?

Regards,
Zhibang