mei: late_bind: add late binding component driver

Introduce a new MEI client driver to support Late Binding firmware
upload/update for Intel discrete graphics platforms.

Late Binding is a runtime firmware upload/update mechanism that allows
payloads, such as fan control and voltage regulator, to be securely
delivered and applied without requiring SPI flash updates or
system reboots. This driver enables the Xe graphics driver and other
user-space tools to push such firmware blobs to the authentication
firmware via the MEI interface.

The driver handles authentication, versioning, and communication
with the authentication firmware, which in turn coordinates with
the PUnit/PCODE to apply the payload.

This is a foundational component for enabling dynamic, secure,
and re-entrant configuration updates on platforms like Battlemage.

Cc: Badal Nilawar <badal.nilawar@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
Reviewed-by: Anshuman Gupta <anshuman.gupta@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250905154953.3974335-3-badal.nilawar@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/include/drm/intel/intel_lb_mei_interface.h b/include/drm/intel/intel_lb_mei_interface.h
new file mode 100644
index 000000000000..d65be2cba2ab
--- /dev/null
+++ b/include/drm/intel/intel_lb_mei_interface.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright (c) 2025 Intel Corporation
+ */
+
+#ifndef _INTEL_LB_MEI_INTERFACE_H_
+#define _INTEL_LB_MEI_INTERFACE_H_
+
+#include <linux/types.h>
+
+struct device;
+
+/**
+ * define INTEL_LB_FLAG_IS_PERSISTENT - Mark the payload as persistent
+ *
+ * This flag indicates that the late binding payload should be stored
+ * persistently in flash across warm resets.
+ */
+#define INTEL_LB_FLAG_IS_PERSISTENT	BIT(0)
+
+/**
+ * enum intel_lb_type - enum to determine late binding payload type
+ * @INTEL_LB_TYPE_FAN_CONTROL: Fan controller configuration
+ */
+enum intel_lb_type {
+	INTEL_LB_TYPE_FAN_CONTROL = 1,
+};
+
+/**
+ * enum intel_lb_status - Status codes returned on late binding transmissions
+ * @INTEL_LB_STATUS_SUCCESS: Operation completed successfully
+ * @INTEL_LB_STATUS_4ID_MISMATCH: Mismatch in the expected 4ID (firmware identity/token)
+ * @INTEL_LB_STATUS_ARB_FAILURE: Arbitration failure (e.g. conflicting access or state)
+ * @INTEL_LB_STATUS_GENERAL_ERROR: General firmware error not covered by other codes
+ * @INTEL_LB_STATUS_INVALID_PARAMS: One or more input parameters are invalid
+ * @INTEL_LB_STATUS_INVALID_SIGNATURE: Payload has an invalid or untrusted signature
+ * @INTEL_LB_STATUS_INVALID_PAYLOAD: Payload contents are not accepted by firmware
+ * @INTEL_LB_STATUS_TIMEOUT: Operation timed out before completion
+ */
+enum intel_lb_status {
+	INTEL_LB_STATUS_SUCCESS           = 0,
+	INTEL_LB_STATUS_4ID_MISMATCH      = 1,
+	INTEL_LB_STATUS_ARB_FAILURE       = 2,
+	INTEL_LB_STATUS_GENERAL_ERROR     = 3,
+	INTEL_LB_STATUS_INVALID_PARAMS    = 4,
+	INTEL_LB_STATUS_INVALID_SIGNATURE = 5,
+	INTEL_LB_STATUS_INVALID_PAYLOAD   = 6,
+	INTEL_LB_STATUS_TIMEOUT           = 7,
+};
+
+/**
+ * struct intel_lb_component_ops - Ops for late binding services
+ */
+struct intel_lb_component_ops {
+	/**
+	 * push_payload - Sends a payload to the authentication firmware
+	 * @dev: Device struct corresponding to the mei device
+	 * @type: Payload type (see &enum intel_lb_type)
+	 * @flags: Payload flags bitmap (e.g. %INTEL_LB_FLAGS_IS_PERSISTENT)
+	 * @payload: Pointer to payload buffer
+	 * @payload_size: Payload buffer size in bytes
+	 *
+	 * Return: 0 success, negative errno value on transport failure,
+	 *         positive status returned by firmware
+	 */
+	int (*push_payload)(struct device *dev, u32 type, u32 flags,
+			    const void *payload, size_t payload_size);
+};
+
+#endif /* _INTEL_LB_MEI_INTERFACE_H_ */