* [PATCH v3 1/5] HID: amd_sfh: Track MP2 version explicitly
2026-08-03 17:52 [PATCH v3 0/5] Add SW_TABLET_MODE support for AMD SFH convertibles Basavaraj Natikar
@ 2026-08-03 17:52 ` Basavaraj Natikar
2026-08-03 17:52 ` [PATCH v3 2/5] HID: amd_sfh: Serialize access to the shared emp2 pointer Basavaraj Natikar
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Basavaraj Natikar @ 2026-08-03 17:52 UTC (permalink / raw)
To: jikos, bentiss, dmitry.torokhov; +Cc: linux-input, Basavaraj Natikar
The MP2 version is currently known only implicitly, from whether an ops
pointer was stored in the PCI driver_data. Subsequent changes need to
act on the MP2 version directly, for example to read the operating-mode
register only on confirmed MP2 v2.
Track the MP2 version explicitly so that version-specific behaviour can
be gated on it, and leave it unset for generations that do not require
such handling.
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
---
drivers/hid/amd-sfh-hid/amd_sfh_common.h | 6 ++++++
drivers/hid/amd-sfh-hid/amd_sfh_pcie.c | 9 +++++----
2 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_common.h b/drivers/hid/amd-sfh-hid/amd_sfh_common.h
index 78f830c133e5..68586f08ab23 100644
--- a/drivers/hid/amd-sfh-hid/amd_sfh_common.h
+++ b/drivers/hid/amd-sfh-hid/amd_sfh_common.h
@@ -35,6 +35,11 @@ enum cmd_id {
STOP_ALL_SENSORS = 8,
};
+enum amd_mp2_version {
+ MP2_VER_V2 = 1,
+ MP2_VER_1_1 = 2,
+};
+
struct amd_mp2_sensor_info {
u8 sensor_idx;
u32 period;
@@ -64,6 +69,7 @@ struct amd_mp2_dev {
struct mutex lock;
u8 init_done;
u8 rver;
+ u8 mp2_ver;
};
struct amd_mp2_ops {
diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
index 4b81cebdc335..92801ca38957 100644
--- a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
+++ b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
@@ -285,6 +285,7 @@ static void mp2_select_ops(struct amd_mp2_dev *privdata)
switch (acs) {
case V2_STATUS:
privdata->mp2_ops = &amd_sfh_ops_v2;
+ privdata->mp2_ver = MP2_VER_V2;
break;
default:
privdata->mp2_ops = &amd_sfh_ops;
@@ -471,8 +472,9 @@ static int amd_mp2_pci_probe(struct pci_dev *pdev, const struct pci_device_id *i
if (rc)
return rc;
- privdata->sfh1_1_ops = (const struct amd_sfh1_1_ops *)id->driver_data;
- if (privdata->sfh1_1_ops) {
+ privdata->mp2_ver = (enum amd_mp2_version)id->driver_data;
+ if (privdata->mp2_ver >= MP2_VER_1_1) {
+ privdata->sfh1_1_ops = &sfh1_1_ops;
if (boot_cpu_data.x86 >= 0x1A)
privdata->rver = 1;
@@ -540,8 +542,7 @@ static SIMPLE_DEV_PM_OPS(amd_mp2_pm_ops, amd_mp2_pci_suspend,
static const struct pci_device_id amd_mp2_pci_tbl[] = {
{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_MP2) },
- { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_MP2_1_1),
- .driver_data = (kernel_ulong_t)&sfh1_1_ops },
+ { PCI_DEVICE_DATA(AMD, MP2_1_1, MP2_VER_1_1) },
{ }
};
MODULE_DEVICE_TABLE(pci, amd_mp2_pci_tbl);
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 2/5] HID: amd_sfh: Serialize access to the shared emp2 pointer
2026-08-03 17:52 [PATCH v3 0/5] Add SW_TABLET_MODE support for AMD SFH convertibles Basavaraj Natikar
2026-08-03 17:52 ` [PATCH v3 1/5] HID: amd_sfh: Track MP2 version explicitly Basavaraj Natikar
@ 2026-08-03 17:52 ` Basavaraj Natikar
2026-08-03 17:52 ` [PATCH v3 3/5] HID: amd_sfh: Add accessor to read the operating-mode sensor Basavaraj Natikar
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Basavaraj Natikar @ 2026-08-03 17:52 UTC (permalink / raw)
To: jikos, bentiss, dmitry.torokhov; +Cc: linux-input, Basavaraj Natikar
The SFH accessors reach the device through a file-global emp2 pointer
that is published at probe and cleared on remove. amd_get_sfh_info() is
exported and called from other modules on unrelated threads, so a reader
can observe a non-NULL emp2 and then race a concurrent unbind that clears
it and frees the device.
Serialize the emp2 publish/clear and all readers under a mutex, so a
reader either sees a live device for the whole access or sees NULL.
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
---
drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c b/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c
index 837d59e7a661..dd2720bae65c 100644
--- a/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c
+++ b/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c
@@ -8,12 +8,14 @@
* Author: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
*/
#include <linux/amd-pmf-io.h>
+#include <linux/cleanup.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/iopoll.h>
#include "amd_sfh_interface.h"
static struct amd_mp2_dev *emp2;
+static DEFINE_MUTEX(emp2_lock);
static int amd_sfh_wait_response(struct amd_mp2_dev *mp2, u8 sid, u32 cmd_id)
{
@@ -78,12 +80,14 @@ static struct amd_mp2_ops amd_sfh_ops = {
void sfh_deinit_emp2(void)
{
+ guard(mutex)(&emp2_lock);
emp2 = NULL;
}
void sfh_interface_init(struct amd_mp2_dev *mp2)
{
mp2->mp2_ops = &amd_sfh_ops;
+ guard(mutex)(&emp2_lock);
emp2 = mp2;
}
@@ -160,6 +164,8 @@ static int amd_sfh_als_info(u32 *ambient_light)
int amd_get_sfh_info(struct amd_sfh_info *sfh_info, enum sfh_message_type op)
{
+ guard(mutex)(&emp2_lock);
+
if (sfh_info) {
switch (op) {
case MT_HPD:
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 3/5] HID: amd_sfh: Add accessor to read the operating-mode sensor
2026-08-03 17:52 [PATCH v3 0/5] Add SW_TABLET_MODE support for AMD SFH convertibles Basavaraj Natikar
2026-08-03 17:52 ` [PATCH v3 1/5] HID: amd_sfh: Track MP2 version explicitly Basavaraj Natikar
2026-08-03 17:52 ` [PATCH v3 2/5] HID: amd_sfh: Serialize access to the shared emp2 pointer Basavaraj Natikar
@ 2026-08-03 17:52 ` Basavaraj Natikar
2026-08-03 17:52 ` [PATCH v3 4/5] HID: amd_sfh: Register tablet-mode auxiliary device Basavaraj Natikar
2026-08-03 17:52 ` [PATCH v3 5/5] Input: misc: Add AMD SFH tablet-mode switch driver Basavaraj Natikar
4 siblings, 0 replies; 6+ messages in thread
From: Basavaraj Natikar @ 2026-08-03 17:52 UTC (permalink / raw)
To: jikos, bentiss, dmitry.torokhov; +Cc: linux-input, Basavaraj Natikar
Allow other drivers to query the operating mode (laptop or tablet)
reported by the Sensor Fusion Hub. This is the interface used by the
tablet-mode switch driver to report the device posture to userspace.
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
---
drivers/hid/amd-sfh-hid/amd_sfh_client.c | 16 +++++++++
drivers/hid/amd-sfh-hid/amd_sfh_common.h | 5 +++
drivers/hid/amd-sfh-hid/amd_sfh_pcie.c | 4 +++
.../amd-sfh-hid/sfh1_1/amd_sfh_interface.c | 33 +++++++++++++++++++
.../amd-sfh-hid/sfh1_1/amd_sfh_interface.h | 1 -
include/linux/amd-pmf-io.h | 14 ++++++++
6 files changed, 72 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_client.c b/drivers/hid/amd-sfh-hid/amd_sfh_client.c
index 96ae792beeb6..ae6add0b9ce3 100644
--- a/drivers/hid/amd-sfh-hid/amd_sfh_client.c
+++ b/drivers/hid/amd-sfh-hid/amd_sfh_client.c
@@ -383,3 +383,19 @@ int amd_sfh_hid_client_deinit(struct amd_mp2_dev *privdata)
return 0;
}
+
+bool amd_sfh_op_idx_enabled(struct amd_mp2_dev *mp2)
+{
+ struct amdtp_cl_data *cl = mp2->cl_data;
+ int i;
+
+ if (!cl)
+ return false;
+
+ for (i = 0; i < cl->num_hid_devices; i++)
+ if (cl->sensor_idx[i] == op_idx &&
+ READ_ONCE(cl->sensor_sts[i]) == SENSOR_ENABLED)
+ return true;
+
+ return false;
+}
diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_common.h b/drivers/hid/amd-sfh-hid/amd_sfh_common.h
index 68586f08ab23..0ca3254151ac 100644
--- a/drivers/hid/amd-sfh-hid/amd_sfh_common.h
+++ b/drivers/hid/amd-sfh-hid/amd_sfh_common.h
@@ -106,4 +106,9 @@ static inline u64 amd_get_p2c_val(struct amd_mp2_dev *mp2, u32 idx)
{
return mp2->rver == 1 ? AMD_P2C_MSG_V1(idx) : AMD_P2C_MSG(idx);
}
+
+bool amd_sfh_op_idx_enabled(struct amd_mp2_dev *mp2);
+void sfh_set_emp2(struct amd_mp2_dev *mp2);
+void sfh_deinit_emp2(void);
+
#endif
diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
index 92801ca38957..4b1cd260410d 100644
--- a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
+++ b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
@@ -251,6 +251,8 @@ int amd_mp2_get_sensor_num(struct amd_mp2_dev *privdata, u8 *sensor_id)
static void amd_mp2_pci_remove(void *privdata)
{
struct amd_mp2_dev *mp2 = privdata;
+
+ sfh_deinit_emp2();
amd_sfh_hid_client_deinit(privdata);
mp2->mp2_ops->stop_all(mp2);
pcim_intx(mp2->pdev, false);
@@ -419,6 +421,7 @@ static void sfh_init_work(struct work_struct *work)
return;
}
+ sfh_set_emp2(mp2);
amd_sfh_clear_intr(mp2);
mp2->init_done = 1;
}
@@ -448,6 +451,7 @@ static int amd_mp2_pci_probe(struct pci_dev *pdev, const struct pci_device_id *i
privdata->pdev = pdev;
dev_set_drvdata(&pdev->dev, privdata);
+
rc = pcim_enable_device(pdev);
if (rc)
return rc;
diff --git a/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c b/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c
index dd2720bae65c..097c5513ccd8 100644
--- a/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c
+++ b/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c
@@ -84,6 +84,12 @@ void sfh_deinit_emp2(void)
emp2 = NULL;
}
+void sfh_set_emp2(struct amd_mp2_dev *mp2)
+{
+ guard(mutex)(&emp2_lock);
+ emp2 = mp2;
+}
+
void sfh_interface_init(struct amd_mp2_dev *mp2)
{
mp2->mp2_ops = &amd_sfh_ops;
@@ -91,6 +97,31 @@ void sfh_interface_init(struct amd_mp2_dev *mp2)
emp2 = mp2;
}
+static int amd_sfh_op_mode_info(u32 *op_mode)
+{
+ struct sfh_op_mode mode;
+ bool present;
+
+ if (!op_mode)
+ return -EINVAL;
+ if (!emp2)
+ return -ENODEV;
+
+ present = emp2->sfh1_1_ops ? emp2->dev_en.is_sra_present
+ : (emp2->mp2_ver == MP2_VER_V2 &&
+ amd_sfh_op_idx_enabled(emp2));
+ if (!present)
+ return -ENODEV;
+
+ mode.val = readl(emp2->mmio + amd_get_c2p_val(emp2, 3));
+ dev_dbg(&emp2->pdev->dev, "op-mode: %s (mode=%u)\n",
+ mode.op_mode.mode == SFH_MODE_TABLET ? "tablet" : "laptop",
+ mode.op_mode.mode);
+ *op_mode = mode.op_mode.mode;
+
+ return 0;
+}
+
static int amd_sfh_mode_info(u32 *platform_type, u32 *laptop_placement)
{
struct sfh_op_mode mode;
@@ -175,6 +206,8 @@ int amd_get_sfh_info(struct amd_sfh_info *sfh_info, enum sfh_message_type op)
case MT_SRA:
return amd_sfh_mode_info(&sfh_info->platform_type,
&sfh_info->laptop_placement);
+ case MT_OP_MODE:
+ return amd_sfh_op_mode_info(&sfh_info->op_mode);
}
}
return -EINVAL;
diff --git a/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.h b/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.h
index 665c99ad779f..56258c4d1b3a 100644
--- a/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.h
+++ b/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.h
@@ -185,7 +185,6 @@ struct sfh_op_mode {
};
void sfh_interface_init(struct amd_mp2_dev *mp2);
-void sfh_deinit_emp2(void);
void amd_sfh1_1_set_desc_ops(struct amd_mp2_ops *mp2_ops);
int amd_sfh_float_to_int(u32 flt32_val);
#endif
diff --git a/include/linux/amd-pmf-io.h b/include/linux/amd-pmf-io.h
index 55198d2875cc..dc59c43bd8f2 100644
--- a/include/linux/amd-pmf-io.h
+++ b/include/linux/amd-pmf-io.h
@@ -19,11 +19,13 @@
* @MT_HPD: Message ID to know the Human presence info from MP2 FW
* @MT_ALS: Message ID to know the Ambient light info from MP2 FW
* @MT_SRA: Message ID to know the SRA data from MP2 FW
+ * @MT_OP_MODE: Message ID to know the operating-mode (tablet/laptop) info
*/
enum sfh_message_type {
MT_HPD,
MT_ALS,
MT_SRA,
+ MT_OP_MODE,
};
/**
@@ -44,12 +46,24 @@ enum sfh_hpd_info {
* @user_present: Populates the user presence information
* @platform_type: Operating modes (clamshell, flat, tent, etc.)
* @laptop_placement: Device states (ontable, onlap, outbag)
+ * @op_mode: Operating-mode field (see enum sfh_dev_mode); used for tablet detection
*/
struct amd_sfh_info {
u32 ambient_light;
u8 user_present;
u32 platform_type;
u32 laptop_placement;
+ u32 op_mode;
+};
+
+/**
+ * enum sfh_dev_mode - SFH operating-mode field (sfh_op_mode.mode, bits 0-2)
+ * @SFH_MODE_LAPTOP: Device is in laptop/clamshell posture
+ * @SFH_MODE_TABLET: Device is in tablet posture
+ */
+enum sfh_dev_mode {
+ SFH_MODE_LAPTOP = 1,
+ SFH_MODE_TABLET = 3,
};
enum laptop_placement {
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 4/5] HID: amd_sfh: Register tablet-mode auxiliary device
2026-08-03 17:52 [PATCH v3 0/5] Add SW_TABLET_MODE support for AMD SFH convertibles Basavaraj Natikar
` (2 preceding siblings ...)
2026-08-03 17:52 ` [PATCH v3 3/5] HID: amd_sfh: Add accessor to read the operating-mode sensor Basavaraj Natikar
@ 2026-08-03 17:52 ` Basavaraj Natikar
2026-08-03 17:52 ` [PATCH v3 5/5] Input: misc: Add AMD SFH tablet-mode switch driver Basavaraj Natikar
4 siblings, 0 replies; 6+ messages in thread
From: Basavaraj Natikar @ 2026-08-03 17:52 UTC (permalink / raw)
To: jikos, bentiss, dmitry.torokhov; +Cc: linux-input, Basavaraj Natikar
Register an auxiliary device when the operating-mode sensor is present,
so a dedicated input driver can bind to it and report the device
posture. This keeps the input handling out of the sensor transport
driver.
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
---
drivers/hid/amd-sfh-hid/Kconfig | 1 +
drivers/hid/amd-sfh-hid/amd_sfh_common.h | 2 +
drivers/hid/amd-sfh-hid/amd_sfh_pcie.c | 50 ++++++++++++++++++++++++
3 files changed, 53 insertions(+)
diff --git a/drivers/hid/amd-sfh-hid/Kconfig b/drivers/hid/amd-sfh-hid/Kconfig
index 3291786a5ee6..d86d83ffebd7 100644
--- a/drivers/hid/amd-sfh-hid/Kconfig
+++ b/drivers/hid/amd-sfh-hid/Kconfig
@@ -6,6 +6,7 @@ menu "AMD SFH HID Support"
config AMD_SFH_HID
tristate "AMD Sensor Fusion Hub"
depends on X86
+ select AUXILIARY_BUS
help
If you say yes to this option, support will be included for the
AMD Sensor Fusion Hub.
diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_common.h b/drivers/hid/amd-sfh-hid/amd_sfh_common.h
index 0ca3254151ac..f8c6b7fc34fb 100644
--- a/drivers/hid/amd-sfh-hid/amd_sfh_common.h
+++ b/drivers/hid/amd-sfh-hid/amd_sfh_common.h
@@ -10,6 +10,7 @@
#ifndef AMD_SFH_COMMON_H
#define AMD_SFH_COMMON_H
+#include <linux/auxiliary_bus.h>
#include <linux/mutex.h>
#include <linux/pci.h>
#include "amd_sfh_hid.h"
@@ -70,6 +71,7 @@ struct amd_mp2_dev {
u8 init_done;
u8 rver;
u8 mp2_ver;
+ struct auxiliary_device *tm_auxdev;
};
struct amd_mp2_ops {
diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
index 4b1cd260410d..1405167aa369 100644
--- a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
+++ b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
@@ -8,11 +8,13 @@
* Basavaraj Natikar <Basavaraj.Natikar@amd.com>
*/
+#include <linux/auxiliary_bus.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/devm-helpers.h>
#include <linux/dma-mapping.h>
#include <linux/dmi.h>
+#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/iopoll.h>
@@ -389,6 +391,51 @@ static const struct attribute_group *amd_sfh_groups[] = {
NULL,
};
+static DEFINE_IDA(sfh_tm_ida);
+
+static void amd_sfh_maybe_register_tm(struct amd_mp2_dev *mp2)
+{
+ struct auxiliary_device *adev;
+ bool present;
+ int id;
+
+ if (mp2->tm_auxdev)
+ return;
+
+ present = mp2->sfh1_1_ops ? mp2->dev_en.is_sra_present
+ : (mp2->mp2_ver == MP2_VER_V2 &&
+ amd_sfh_op_idx_enabled(mp2));
+ if (!present)
+ return;
+
+ id = ida_alloc(&sfh_tm_ida, GFP_KERNEL);
+ if (id < 0)
+ return;
+
+ adev = auxiliary_device_create(&mp2->pdev->dev, KBUILD_MODNAME,
+ "tabletmode", NULL, id);
+ if (!adev) {
+ ida_free(&sfh_tm_ida, id);
+ dev_warn(&mp2->pdev->dev, "tabletmode auxdev create failed\n");
+ return;
+ }
+
+ mp2->tm_auxdev = adev;
+}
+
+static void amd_sfh_unregister_tm(struct amd_mp2_dev *mp2)
+{
+ int id;
+
+ if (!mp2->tm_auxdev)
+ return;
+
+ id = mp2->tm_auxdev->id;
+ auxiliary_device_destroy(mp2->tm_auxdev);
+ mp2->tm_auxdev = NULL;
+ ida_free(&sfh_tm_ida, id);
+}
+
static void sfh1_1_init_work(struct work_struct *work)
{
struct amd_mp2_dev *mp2 = container_of(work, struct amd_mp2_dev, work);
@@ -405,6 +452,7 @@ static void sfh1_1_init_work(struct work_struct *work)
if (rc)
dev_warn(&mp2->pdev->dev, "failed to update sysfs group\n");
+ amd_sfh_maybe_register_tm(mp2);
}
static void sfh_init_work(struct work_struct *work)
@@ -424,6 +472,7 @@ static void sfh_init_work(struct work_struct *work)
sfh_set_emp2(mp2);
amd_sfh_clear_intr(mp2);
mp2->init_done = 1;
+ amd_sfh_maybe_register_tm(mp2);
}
static void amd_sfh_remove(struct pci_dev *pdev)
@@ -431,6 +480,7 @@ static void amd_sfh_remove(struct pci_dev *pdev)
struct amd_mp2_dev *mp2 = pci_get_drvdata(pdev);
flush_work(&mp2->work);
+ amd_sfh_unregister_tm(mp2);
if (mp2->init_done)
mp2->mp2_ops->remove(mp2);
}
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 5/5] Input: misc: Add AMD SFH tablet-mode switch driver
2026-08-03 17:52 [PATCH v3 0/5] Add SW_TABLET_MODE support for AMD SFH convertibles Basavaraj Natikar
` (3 preceding siblings ...)
2026-08-03 17:52 ` [PATCH v3 4/5] HID: amd_sfh: Register tablet-mode auxiliary device Basavaraj Natikar
@ 2026-08-03 17:52 ` Basavaraj Natikar
4 siblings, 0 replies; 6+ messages in thread
From: Basavaraj Natikar @ 2026-08-03 17:52 UTC (permalink / raw)
To: jikos, bentiss, dmitry.torokhov
Cc: linux-input, Basavaraj Natikar, Helge Bahmann
Report whether an AMD convertible is in laptop or tablet mode using the
operating-mode sensor provided by the Sensor Fusion Hub, and expose it
to userspace as SW_TABLET_MODE, so userspace can react to the device
being folded into tablet posture.
Cc: Helge Bahmann <hcb@chaoticmind.net>
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
MAINTAINERS | 1 +
drivers/input/misc/Kconfig | 15 +++++
drivers/input/misc/Makefile | 1 +
drivers/input/misc/amd_sfh_tabletmode.c | 81 +++++++++++++++++++++++++
4 files changed, 98 insertions(+)
create mode 100644 drivers/input/misc/amd_sfh_tabletmode.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 5114e6db7307..30b429eb9286 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1301,6 +1301,7 @@ L: linux-input@vger.kernel.org
S: Maintained
F: Documentation/hid/amd-sfh*
F: drivers/hid/amd-sfh-hid/
+F: drivers/input/misc/amd_sfh_tabletmode.c
AMD SPI DRIVER
M: Raju Rangoju <Raju.Rangoju@amd.com>
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 1f6c57dba030..5b76be31f687 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -899,6 +899,21 @@ config INPUT_SOC_BUTTON_ARRAY
To compile this driver as a module, choose M here: the
module will be called soc_button_array.
+config INPUT_AMD_SFH_TABLETMODE
+ tristate "AMD SFH tablet-mode switch"
+ depends on AMD_SFH_HID
+ select AUXILIARY_BUS
+ help
+ Expose SW_TABLET_MODE for AMD convertible laptops whose
+ operation-mode sensor is provided by the AMD Sensor Fusion Hub.
+
+ Userspace components such as systemd-logind and modern desktop
+ environments react to SW_TABLET_MODE when the device is folded
+ into tablet posture.
+
+ To compile this driver as a module, choose M here: the module
+ will be called amd_sfh_tabletmode.
+
config INPUT_DRV260X_HAPTICS
tristate "TI DRV260X haptics support"
depends on INPUT && I2C
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 2281d6803fce..6fab9acf3de3 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_INPUT_AD714X_SPI) += ad714x-spi.o
obj-$(CONFIG_INPUT_ADXL34X) += adxl34x.o
obj-$(CONFIG_INPUT_ADXL34X_I2C) += adxl34x-i2c.o
obj-$(CONFIG_INPUT_ADXL34X_SPI) += adxl34x-spi.o
+obj-$(CONFIG_INPUT_AMD_SFH_TABLETMODE) += amd_sfh_tabletmode.o
obj-$(CONFIG_INPUT_APANEL) += apanel.o
obj-$(CONFIG_INPUT_ARIEL_PWRBUTTON) += ariel-pwrbutton.o
obj-$(CONFIG_INPUT_ARIZONA_HAPTICS) += arizona-haptics.o
diff --git a/drivers/input/misc/amd_sfh_tabletmode.c b/drivers/input/misc/amd_sfh_tabletmode.c
new file mode 100644
index 000000000000..3931a1c6eb74
--- /dev/null
+++ b/drivers/input/misc/amd_sfh_tabletmode.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * AMD SFH tablet-mode switch driver
+ *
+ * Copyright (c) 2026, Advanced Micro Devices, Inc.
+ * All Rights Reserved.
+ *
+ * Author: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
+ */
+
+#include <linux/amd-pmf-io.h>
+#include <linux/auxiliary_bus.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/pci_ids.h>
+
+#define POLL_INTERVAL_MS 200
+
+static void sfh_tm_poll(struct input_dev *input)
+{
+ struct amd_sfh_info info = {};
+
+ if (amd_get_sfh_info(&info, MT_OP_MODE))
+ return;
+
+ input_report_switch(input, SW_TABLET_MODE,
+ info.op_mode == SFH_MODE_TABLET);
+ input_sync(input);
+}
+
+static int sfh_tm_probe(struct auxiliary_device *auxdev,
+ const struct auxiliary_device_id *id)
+{
+ struct device *dev = &auxdev->dev;
+ struct amd_sfh_info info = {};
+ struct input_dev *input;
+ int error;
+
+ error = amd_get_sfh_info(&info, MT_OP_MODE);
+ if (error)
+ return error == -EINVAL ? -ENODEV : error;
+
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return -ENOMEM;
+
+ input->name = "AMD SFH tablet mode switch";
+ input->phys = "amd-sfh/tabletmode";
+ input->id.bustype = BUS_HOST;
+ input->id.vendor = PCI_VENDOR_ID_AMD;
+ input_set_capability(input, EV_SW, SW_TABLET_MODE);
+
+ error = input_setup_polling(input, sfh_tm_poll);
+ if (error)
+ return error;
+ input_set_poll_interval(input, POLL_INTERVAL_MS);
+
+ sfh_tm_poll(input);
+
+ error = input_register_device(input);
+ if (error)
+ return error;
+
+ return 0;
+}
+
+static const struct auxiliary_device_id sfh_tm_id_table[] = {
+ { .name = "amd_sfh.tabletmode" },
+ {}
+};
+MODULE_DEVICE_TABLE(auxiliary, sfh_tm_id_table);
+
+static struct auxiliary_driver sfh_tm_driver = {
+ .name = "tabletmode",
+ .id_table = sfh_tm_id_table,
+ .probe = sfh_tm_probe,
+};
+module_auxiliary_driver(sfh_tm_driver);
+
+MODULE_DESCRIPTION("AMD SFH tablet mode switch");
+MODULE_LICENSE("GPL");
--
2.34.1
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