[PATCH RFC 02/18] accel/qda: Add Qualcomm DSP accelerator driver skeleton

[Ekansh Gupta]

This patch introduces the initial scaffolding for the Qualcomm DSP
accelerator (QDA) driver under drivers/accel/.
The new Kconfig option DRM_ACCEL_QDA integrates the driver with the
DRM/accel subsystem, and the accel Makefile is updated to build the
driver as a loadable module. A minimal qda_drv.c file is added to
provide basic module_init/module_exit hooks so that the driver can be
built and loaded.

Subsequent patches will add:

- RPMSG-based communication with Qualcomm Hexagon DSPs
- FastRPC integration for userspace offload
- DMA-BUF support and memory management
- GEM, PRIME and IOCTL interfaces for compute job submission

This patch only wires up the basic driver framework and does not yet
provide functional DSP offload capabilities.

Signed-off-by: Ekansh Gupta <ekansh.gupta@xxxxxxxxxxxxxxxx>
---
 drivers/accel/Kconfig       |  1 +
 drivers/accel/Makefile      |  1 +
 drivers/accel/qda/Kconfig   | 29 +++++++++++++++++++++++++++++
 drivers/accel/qda/Makefile  |  8 ++++++++
 drivers/accel/qda/qda_drv.c | 22 ++++++++++++++++++++++
 5 files changed, 61 insertions(+)

diff --git a/drivers/accel/Kconfig b/drivers/accel/Kconfig
index bdf48ccafcf2..74ac0f71bc9d 100644
--- a/drivers/accel/Kconfig
+++ b/drivers/accel/Kconfig
@@ -29,6 +29,7 @@ source "drivers/accel/ethosu/Kconfig"
 source "drivers/accel/habanalabs/Kconfig"
 source "drivers/accel/ivpu/Kconfig"
 source "drivers/accel/qaic/Kconfig"
+source "drivers/accel/qda/Kconfig"
 source "drivers/accel/rocket/Kconfig"
 
 endif
diff --git a/drivers/accel/Makefile b/drivers/accel/Makefile
index 1d3a7251b950..58c08dd5f389 100644
--- a/drivers/accel/Makefile
+++ b/drivers/accel/Makefile
@@ -5,4 +5,5 @@ obj-$(CONFIG_DRM_ACCEL_ARM_ETHOSU)	+= ethosu/
 obj-$(CONFIG_DRM_ACCEL_HABANALABS)	+= habanalabs/
 obj-$(CONFIG_DRM_ACCEL_IVPU)		+= ivpu/
 obj-$(CONFIG_DRM_ACCEL_QAIC)		+= qaic/
+obj-$(CONFIG_DRM_ACCEL_QDA)		+= qda/
 obj-$(CONFIG_DRM_ACCEL_ROCKET)		+= rocket/
\ No newline at end of file
diff --git a/drivers/accel/qda/Kconfig b/drivers/accel/qda/Kconfig
new file mode 100644
index 000000000000..3c78ff6189e0
--- /dev/null
+++ b/drivers/accel/qda/Kconfig
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Qualcomm DSP accelerator driver
+#
+
+config DRM_ACCEL_QDA
+	tristate "Qualcomm DSP accelerator"
+	depends on DRM_ACCEL
+	depends on ARCH_QCOM || COMPILE_TEST
+	help
+	  Enables the DRM-based accelerator driver for Qualcomm's Hexagon DSPs.
+	  This driver provides a standardized interface for offloading computational
+	  tasks to the DSP, including audio processing, sensor offload, computer
+	  vision, and AI inference workloads.
+
+	  The driver supports all DSP domains (ADSP, CDSP, SDSP, GDSP) and
+	  implements the FastRPC protocol for communication between the application
+	  processor and DSP. It integrates with the Linux kernel's Compute
+	  Accelerators subsystem (drivers/accel/) and provides a modern alternative
+	  to the legacy FastRPC driver found in drivers/misc/.
+
+	  Key features include DMA-BUF interoperability for seamless buffer sharing
+	  with other multimedia subsystems, IOMMU-based memory isolation, and
+	  standard DRM IOCTLs for device management and job submission.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called qda.
diff --git a/drivers/accel/qda/Makefile b/drivers/accel/qda/Makefile
new file mode 100644
index 000000000000..573711af1d28
--- /dev/null
+++ b/drivers/accel/qda/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for Qualcomm DSP accelerator driver
+#
+
+obj-$(CONFIG_DRM_ACCEL_QDA)	:= qda.o
+
+qda-y := qda_drv.o
diff --git a/drivers/accel/qda/qda_drv.c b/drivers/accel/qda/qda_drv.c
new file mode 100644
index 000000000000..18b0d3fb1598
--- /dev/null
+++ b/drivers/accel/qda/qda_drv.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+static int __init qda_core_init(void)
+{
+	pr_info("QDA: driver initialization complete\n");
+	return 0;
+}
+
+static void __exit qda_core_exit(void)
+{
+	pr_info("QDA: driver exit complete\n");
+}
+
+module_init(qda_core_init);
+module_exit(qda_core_exit);
+
+MODULE_AUTHOR("Qualcomm AI Infra Team");
+MODULE_DESCRIPTION("Qualcomm DSP Accelerator Driver");
+MODULE_LICENSE("GPL");

-- 
2.34.1