On 19/08/2026 15:17, Ekansh Gupta wrote:
On 19-08-2026 00:40, Krzysztof Kozlowski wrote:
On 17/08/2026 06:47, Ekansh Gupta wrote:
Add the skeleton of the Qualcomm DSP Accelerator (QDA) driver, a DRM accel driver for the Hexagon DSPs found on Qualcomm SoCs.
This patch registers a DRM accel device, exposing a /dev/accel/accelN character device node, and binds it to the RPMsg channel used to reach the DSP. Buffer management, IOMMU context banks and the FastRPC protocol are added by later patches in this series.
qda_drv.c / qda_drv.h define the drm_driver ops table, the per-file private state (qda_file_priv) and the main device structure (qda_dev), which embeds drm_device so that it can be recovered with container_of().
qda_rpmsg.c binds to the "qcom,fastrpc" compatible via module_rpmsg_driver(), reads the DSP domain name from the "label" device-tree property, and registers the DRM device.
Assisted-by: Claude:claude-sonnet-5 Signed-off-by: Ekansh Gupta ekansh.gupta@oss.qualcomm.com
Changes in v2:
- Use module_rpmsg_driver() and drop the qda_rpmsg_register()/ _unregister() wrappers, module_init()/module_exit() and qda_rpmsg.h entirely (Dmitry Baryshkov)
- Read the "label" property directly into qdev->dsp_name (Dmitry Baryshkov)
- Drop the probe/remove/init log messages (Dmitry Baryshkov)
- Return the result of qda_register_device() directly (Dmitry Baryshkov)
- Clarify the Kconfig help text (Dmitry Baryshkov)
drivers/accel/Kconfig | 1 + drivers/accel/Makefile | 1 + drivers/accel/qda/Kconfig | 30 ++++++++++++++++ drivers/accel/qda/Makefile | 10 ++++++ drivers/accel/qda/qda_drv.c | 71 ++++++++++++++++++++++++++++++++++++++ drivers/accel/qda/qda_drv.h | 61 +++++++++++++++++++++++++++++++++ drivers/accel/qda/qda_rpmsg.c | 79 +++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 253 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
You have trivial patch errors.
newline problem was already there, wasn't introduced as part of this patch series, so I wasn't sure to fix it here. I can fix this in v3.>
...
+}
+static const struct of_device_id qda_rpmsg_id_table[] = {
- { .compatible = "qcom,fastrpc" },
- {},
Device node with this compatible is already populated, so this looks simply wrong or you are adding a duplicated driver.
That's a no-go, you are supposed to work with existing drivers and grow them.
I'll bring the discussion again here, there was a discussion to move the driver to accel subsystem if we want to support new features/uAPI changes. Please read [1],[2] threads. The intention is to replace fastrpc driver with QDA eventually.
None of them address the problem. You want to grow fastrpc into user of dmabuf? So you move it from misc to here.
Again: you have one driver.
Do you suggest adding a different compatible, say "qcom,qda" for this driver?
How would that even work? How much (or many?) hardware do you have in your SoC?
Let me know if you have a better suggestion to proceed here.
[1] https://lkml.org/lkml/2024/6/24/479 [2] https://lkml.org/lkml/2024/6/21/1252%3E
Please do not ever reference lkml.org, it's long time deprecated and barely working. Use lore.
Best regards, Krzysztof