[PATCH v6] Bluetooth: btintel_pcie: Add vendor_reset PCI sysfs for PLDR

Add a read-write sysfs entry at /sys/bus/pci/devices/<BDF>/vendor_reset
to allow userspace to trigger PLDR (Product Level Device Reset).
Reading the attribute displays supported reset types. Writing
integer 0 triggers PLDR. Any other input is rejected with
-EINVAL and a warning log.

Signed-off-by: Chandrashekar Devegowda <[email protected]>
---
Changes in v6:
  - Fixed .driver.dev_groups -> .dev_groups on struct pci_driver
    (__pci_register_driver overwrites .driver.dev_groups with .dev_groups)
  - Removed unrelated schedule_work() failure handling from
    btintel_pcie_request_reset() that caused CI context mismatch

Changes in v5:
  - Renamed sysfs from vendor_rst to vendor_reset (reviewer feedback)
  - Switched from device_create_file() to driver dev_groups for
    automatic race-free sysfs lifecycle management
  - Added ABI doc at Documentation/ABI/testing/sysfs-bus-pci-drivers-btintel_pcie
  - Added WiFi impact description to ABI documentation
  - Added MAINTAINERS F: entry for ABI doc
  - v5: https://lore.kernel.org/all/[email protected]/

Changes in v4:
  - Rebased on latest bluetooth-next to fix CI apply failure
  - v4: https://lore.kernel.org/all/[email protected]/

Changes in v3:
  - Dropped reset_type parameter approach from hdev->reset()
  - Directly call btintel_pcie_request_reset() instead of manual
    flag manipulation and schedule_work()
  - Accept only integer 0 for PLDR trigger
  - v3: https://lore.kernel.org/all/[email protected]/

Changes in v2:
  - Added reset_type parameter to hdev->reset() callback (1/2)
  - vendor_rst sysfs used reset_type to select PLDR (2/2)
  - v2: https://lore.kernel.org/all/[email protected]/

Changes in v1:
  - Initial implementation
  - v1: https://lore.kernel.org/all/[email protected]/
 .../sysfs-bus-pci-drivers-btintel_pcie        | 15 ++++++++
 MAINTAINERS                                   |  1 +
 drivers/bluetooth/btintel_pcie.c              | 38 +++++++++++++++++++
 3 files changed, 54 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-pci-drivers-btintel_pcie

diff --git a/Documentation/ABI/testing/sysfs-bus-pci-drivers-btintel_pcie b/Documentation/ABI/testing/sysfs-bus-pci-drivers-btintel_pcie
new file mode 100644
index 000000000000..cceec6ac96bc
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-pci-drivers-btintel_pcie
@@ -0,0 +1,15 @@
+What:		/sys/bus/pci/devices/<BDF>/vendor_reset
+Date:		22-Jul-2026
+KernelVersion:	6.17
+Contact:	[email protected]
+Description:	This read-write attribute allows userspace to trigger a
+		Product Level Device Reset (PLDR) on Intel PCIe Bluetooth
+		controllers. Reading the attribute displays the supported
+		reset type. Writing integer 0 triggers PLDR. Any other
+		input is rejected with -EINVAL.
+
+		PLDR resets the entire on-chip platform shared between
+		Bluetooth and WiFi. This means any driver attached to
+		the WiFi device that shares hardware with this Bluetooth
+		device will be released, the platform will be reset, and
+		both the Bluetooth and WiFi devices will be re-probed.
diff --git a/MAINTAINERS b/MAINTAINERS
index eb8cdcc76324..39d390f1ceb4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4625,6 +4625,7 @@ S:	Supported
 W:	http://www.bluez.org/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.git
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git
+F:	Documentation/ABI/testing/sysfs-bus-pci-drivers-btintel_pcie
 F:	Documentation/devicetree/bindings/net/bluetooth/
 F:	drivers/bluetooth/
 
diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c
index ef42b8d11d4d..005c77a4f5eb 100644
--- a/drivers/bluetooth/btintel_pcie.c
+++ b/drivers/bluetooth/btintel_pcie.c
@@ -2790,6 +2790,43 @@ static void btintel_pcie_hci_reset(struct hci_dev *hdev)
 	btintel_pcie_request_reset(data, BTINTEL_PCIE_IOSF_PRR_FLR);
 }
 
+static ssize_t vendor_reset_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	unsigned int val;
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct btintel_pcie_data *data = pci_get_drvdata(pdev);
+
+	if (!data || !data->hdev)
+		return -ENODEV;
+
+	if (kstrtouint(buf, 10, &val) || val != 0) {
+		bt_dev_warn(data->hdev, "PLDR rejected: invalid input");
+		return -EINVAL;
+	}
+
+	bt_dev_info(data->hdev, "PLDR triggered via sysfs");
+	btintel_pcie_request_reset(data, BTINTEL_PCIE_IOSF_PRR_PLDR);
+
+	return count;
+}
+
+static ssize_t vendor_reset_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "0 - PLDR\n");
+}
+
+static DEVICE_ATTR_RW(vendor_reset);
+
+static struct attribute *btintel_pcie_attrs[] = {
+	&dev_attr_vendor_reset.attr,
+	NULL,
+};
+
+ATTRIBUTE_GROUPS(btintel_pcie);
+
 static void btintel_pcie_hw_error(struct hci_dev *hdev, u8 code)
 {
 	struct btintel_pcie_dev_recovery *rec;
@@ -3250,6 +3287,7 @@ static struct pci_driver btintel_pcie_driver = {
 	.probe = btintel_pcie_probe,
 	.remove = btintel_pcie_remove,
 	.driver.pm = pm_sleep_ptr(&btintel_pcie_pm_ops),
+	.dev_groups = btintel_pcie_groups,
 #ifdef CONFIG_DEV_COREDUMP
 	.driver.coredump = btintel_pcie_coredump
 #endif
-- 
2.43.0