[PATCH -next v2 2/4] HID: amd_sfh: Add operating-mode telemetry sysfs attributes

[Basavaraj Natikar <Basavaraj.Natikar@amd.com>]

The Sensor Fusion Hub reports additional operating-mode telemetry
through the SRA sensor, such as in-bag and out-of-bag detection,
on-table or on-lap placement, hinge angle, lid status and the platform
device mode.

Expose these states read-only through sysfs so that userspace can
consume them. The attributes are visible only on SFH 1.1 or greater when
the SRA sensor is present.

Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
---
 .../ABI/testing/sysfs-driver-amd-sfh          | 60 ++++++++++++++++++
 MAINTAINERS                                   |  1 +
 drivers/hid/amd-sfh-hid/amd_sfh_sysfs.c       | 63 ++++++++++++++++++-
 3 files changed, 123 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-driver-amd-sfh b/Documentation/ABI/testing/sysfs-driver-amd-sfh
index c053126a83bb..15abd994e9ee 100644
--- a/Documentation/ABI/testing/sysfs-driver-amd-sfh
+++ b/Documentation/ABI/testing/sysfs-driver-amd-sfh
@@ -11,3 +11,63 @@ Description:
 
 		Access: Read/Write
 		Valid values: enabled/disabled
+
+What:		/sys/bus/pci/drivers/pcie_mp2_amd/*/in_bag_state
+Date:		August 2026
+Contact:	Basavaraj.Natikar@amd.com
+Description:
+		Operating-mode telemetry reported by the SRA sensor that
+		indicates whether the device is detected inside a bag.
+
+		Access: Read only
+		Valid values: unsigned integer
+
+What:		/sys/bus/pci/drivers/pcie_mp2_amd/*/out_bag_state
+Date:		August 2026
+Contact:	Basavaraj.Natikar@amd.com
+Description:
+		Operating-mode telemetry reported by the SRA sensor that
+		indicates whether the device is detected outside a bag.
+
+		Access: Read only
+		Valid values: unsigned integer
+
+What:		/sys/bus/pci/drivers/pcie_mp2_amd/*/on_table_state
+Date:		August 2026
+Contact:	Basavaraj.Natikar@amd.com
+Description:
+		Operating-mode telemetry reported by the SRA sensor that
+		indicates whether the device is placed on a table or on a lap.
+
+		Access: Read only
+		Valid values: unsigned integer
+
+What:		/sys/bus/pci/drivers/pcie_mp2_amd/*/hinge_angle
+Date:		August 2026
+Contact:	Basavaraj.Natikar@amd.com
+Description:
+		Operating-mode telemetry reported by the SRA sensor that
+		reports the hinge angle of the device in degrees.
+
+		Access: Read only
+		Valid values: unsigned integer (degrees)
+
+What:		/sys/bus/pci/drivers/pcie_mp2_amd/*/lid_status
+Date:		August 2026
+Contact:	Basavaraj.Natikar@amd.com
+Description:
+		Operating-mode telemetry reported by the SRA sensor that
+		indicates whether the device lid is open or closed.
+
+		Access: Read only
+		Valid values: unsigned integer
+
+What:		/sys/bus/pci/drivers/pcie_mp2_amd/*/device_mode
+Date:		August 2026
+Contact:	Basavaraj.Natikar@amd.com
+Description:
+		Operating-mode telemetry reported by the SRA sensor that
+		reports the platform/device mode.
+
+		Access: Read only
+		Valid values: unsigned integer
diff --git a/MAINTAINERS b/MAINTAINERS
index 5c57cbb68060..ad3477693db5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1331,6 +1331,7 @@ AMD SENSOR FUSION HUB DRIVER
 M:	Basavaraj Natikar <basavaraj.natikar@amd.com>
 L:	linux-input@vger.kernel.org
 S:	Maintained
+F:	Documentation/ABI/testing/sysfs-driver-amd-sfh
 F:	Documentation/hid/amd-sfh*
 F:	drivers/hid/amd-sfh-hid/
 F:	drivers/input/misc/amd_sfh_tabletmode.c
diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_sysfs.c b/drivers/hid/amd-sfh-hid/amd_sfh_sysfs.c
index db1cc205d25b..8af4df09760f 100644
--- a/drivers/hid/amd-sfh-hid/amd_sfh_sysfs.c
+++ b/drivers/hid/amd-sfh-hid/amd_sfh_sysfs.c
@@ -8,6 +8,7 @@
  * Author: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
  */
 #include <linux/device.h>
+#include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/string_choices.h>
 #include <linux/sysfs.h>
@@ -15,6 +16,7 @@
 #include "amd_sfh_common.h"
 #include "amd_sfh_sysfs.h"
 #include "sfh1_1/amd_sfh_init.h"
+#include "sfh1_1/amd_sfh_interface.h"
 
 static ssize_t hpd_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
@@ -41,19 +43,78 @@ static ssize_t hpd_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(hpd);
 
+/* Operating-mode telemetry reported by the SRA sensor, exposed read-only. */
+static int amd_sfh_read_op_mode(struct amd_mp2_dev *mp2, struct sfh_op_mode *mode)
+{
+	struct sfh_accel_data accel_data;
+	void __iomem *sensoraddr;
+
+	if (!mp2->sfh1_1_ops || !mp2->dev_en.is_sra_present)
+		return -ENODEV;
+
+	if (mp2->mp2_ver >= MP2_VER_1_2) {
+		sensoraddr = mp2->vsbase +
+			(SRA_IDX * SENSOR_DATA_MEM_SIZE_DEFAULT) +
+			OFFSET_SENSOR_DATA_DEFAULT;
+		memcpy_fromio(&accel_data, sensoraddr, sizeof(struct sfh_accel_data));
+		mode->val = accel_data.c2p3_data;
+	} else {
+		mode->val = readl(mp2->mmio + amd_get_c2p_val(mp2, 3));
+	}
+
+	return 0;
+}
+
+#define SFH_OP_MODE_ATTR(_name, _field)					\
+static ssize_t _name##_show(struct device *dev,				\
+			    struct device_attribute *attr, char *buf)	\
+{									\
+	struct amd_mp2_dev *mp2 = dev_get_drvdata(dev);			\
+	struct sfh_op_mode mode;					\
+	int ret;							\
+									\
+	ret = amd_sfh_read_op_mode(mp2, &mode);				\
+	if (ret)							\
+		return ret;						\
+									\
+	return sysfs_emit(buf, "%u\n", mode.op_mode._field);		\
+}									\
+static DEVICE_ATTR_RO(_name)
+
+SFH_OP_MODE_ATTR(in_bag_state, inbagstate);
+SFH_OP_MODE_ATTR(out_bag_state, outbagstate);
+SFH_OP_MODE_ATTR(on_table_state, ontablestate);
+SFH_OP_MODE_ATTR(hinge_angle, angle);
+SFH_OP_MODE_ATTR(lid_status, lidstatus);
+SFH_OP_MODE_ATTR(device_mode, devicemode);
+
 static umode_t sfh_attr_is_visible(struct kobject *kobj, struct attribute *attr, int idx)
 {
 	struct device *dev = kobj_to_dev(kobj);
 	struct amd_mp2_dev *mp2 = dev_get_drvdata(dev);
 
-	if (!mp2->sfh1_1_ops || !mp2->dev_en.is_hpd_present)
+	if (!mp2->sfh1_1_ops)
+		return 0;
+
+	if (attr == &dev_attr_hpd.attr) {
+		if (!mp2->dev_en.is_hpd_present)
+			return 0;
+	} else if (!mp2->dev_en.is_sra_present) {
+		/* operating-mode telemetry requires the SRA sensor */
 		return 0;
+	}
 
 	return attr->mode;
 }
 
 static struct attribute *sfh_attrs[] = {
 	&dev_attr_hpd.attr,
+	&dev_attr_in_bag_state.attr,
+	&dev_attr_out_bag_state.attr,
+	&dev_attr_on_table_state.attr,
+	&dev_attr_hinge_angle.attr,
+	&dev_attr_lid_status.attr,
+	&dev_attr_device_mode.attr,
 	NULL,
 };
 
-- 
2.34.1