[PATCH v2 4/9] accel/neutron: Add driver for NXP Neutron NPU

[Ioana Ciocoi Radulescu]

On Friday, March 6, 2026 at 4:22 PM, Krzysztof Kozlowski wrote:
> On 06/03/2026 14:27, Ioana Ciocoi-Radulescu wrote:
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS index
> > 8a5b27b061da..f7a687eb6b54 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -19191,6 +19191,16 @@ S:	Orphan
> >  F:	Documentation/devicetree/bindings/net/nfc/nxp,nci.yaml
> >  F:	drivers/nfc/nxp-nci
> >
> > +NXP Neutron NPU DRIVER
> 
> s/Neutron/NEUTRON/ as everything here is in uppercase

Ok.

> 
> > +M:	Ioana Ciocoi Radulescu <ruxandra.radulescu at nxp.com>
> > +M:	Jiwei Fu <jiwei.fu at nxp.com>
> > +L:	dri-devel at lists.freedesktop.org
> > +S:	Maintained
> > +T:	git https://gitlab.freedesktop.org/drm/misc/kernel.git
> > +F:	Documentation/accel/neutron/
> > +F:	drivers/accel/neutron/
> > +F:	include/uapi/drm/neutron_accel.h
> 
> 
> >
> > diff --git a/drivers/accel/Makefile b/drivers/accel/Makefile index
> > 1d3a7251b950..698136e12cce 100644
> > --- a/drivers/accel/Makefile
> > +++ b/drivers/accel/Makefile
> > @@ -4,5 +4,6 @@ obj-$(CONFIG_DRM_ACCEL_AMDXDNA)		+=
> amdxdna/
> >  obj-$(CONFIG_DRM_ACCEL_ARM_ETHOSU)	+= ethosu/
> >  obj-$(CONFIG_DRM_ACCEL_HABANALABS)	+= habanalabs/
> >  obj-$(CONFIG_DRM_ACCEL_IVPU)		+= ivpu/
> > +obj-$(CONFIG_DRM_ACCEL_NXP_NEUTRON)	+= neutron/
> >  obj-$(CONFIG_DRM_ACCEL_QAIC)		+= qaic/
> > -obj-$(CONFIG_DRM_ACCEL_ROCKET)		+= rocket/
> > \ No newline at end of file
> 
> You still have patch warnings.

Yeah, so the last line of this Makefile lacked the line ending and vim
fixed that on its own when I edited the file. I can add the neutron line
and leave the rest untouched, just making sure this is what you're
requesting?

> 
> > +obj-$(CONFIG_DRM_ACCEL_ROCKET)		+= rocket/
> > diff --git a/drivers/accel/neutron/Kconfig
> > b/drivers/accel/neutron/Kconfig new file mode 100644 index
> > 000000000000..37b8ecb49804
> > --- /dev/null
> > +++ b/drivers/accel/neutron/Kconfig
> > @@ -0,0 +1,16 @@
> > +# SPDX-License-Identifier: GPL-2.0+
> > +
> > +config DRM_ACCEL_NXP_NEUTRON
> > +	tristate "NXP Neutron NPU"
> > +	depends on HAS_IOMEM
> > +	depends on DRM_ACCEL
> > +	depends on ARCH_MXC
> 
> Missing compile test

Will add.

> 
> > +	select DRM_GEM_DMA_HELPER
> > +	select DRM_SCHED
> > +	help
> > +	  Enables driver for NXP Neutron NPU.
> > +
> > +	  Select this if you have an NXP SoC with Neutron, like i.MX95,
> > +	  and want to run machine learning applications.
> > +
> > +	  If built as module, the module is named neutron.
> 
> ...
> 
> > +
> > +	ret = devm_request_threaded_irq(dev, ndev->irq, NULL,
> > +					neutron_irq_handler_thread,
> > +					IRQF_ONESHOT, KBUILD_MODNAME,
> ndev);
> > +	if (ret) {
> > +		dev_err(dev, "Failed to request irq %d\n", ndev->irq);
> 
> Drop, not needed.

Ok

> 
> > +		return ret;
> > +	}
> > +
> > +	ret = of_reserved_mem_device_init(&pdev->dev);
> > +	if (ret) {
> > +		dev_err(dev, "Failed to initialize reserved memory\n");
> > +		return ret;
> > +	}
> > +
> > +	ret = devm_pm_runtime_enable(dev);
> > +	if (ret)
> > +		goto free_reserved;
> > +
> > +	pm_runtime_set_autosuspend_delay(dev,
> NEUTRON_SUSPEND_DELAY_MS);
> > +	pm_runtime_use_autosuspend(dev);
> > +
> > +	ret = drm_dev_register(&ndev->base, 0);
> > +	if (ret)
> > +		goto free_reserved;
> > +
> > +	return 0;
> > +
> > +free_reserved:
> > +	of_reserved_mem_device_release(&pdev->dev);
> > +
> > +	return ret;
> > +}
> > +
> > +static void neutron_remove(struct platform_device *pdev) {
> > +	struct neutron_device *ndev = platform_get_drvdata(pdev);
> > +
> > +	drm_dev_unregister(&ndev->base);
> > +	of_reserved_mem_device_release(&pdev->dev);
> > +}
> > +
> > +static int neutron_runtime_suspend(struct device *dev) {
> > +	struct neutron_device *ndev = dev_get_drvdata(dev);
> > +
> > +	neutron_disable_irq(ndev);
> > +	neutron_shutdown(ndev);
> > +
> > +	clk_bulk_disable_unprepare(ndev->num_clks, ndev->clks);
> > +
> > +	return 0;
> > +}
> > +
> > +static int neutron_runtime_resume(struct device *dev) {
> > +	struct neutron_device *ndev = dev_get_drvdata(dev);
> > +	int ret;
> > +
> > +	ret = clk_bulk_prepare_enable(ndev->num_clks, ndev->clks);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = neutron_boot(ndev);
> > +	if (ret) {
> > +		clk_bulk_disable_unprepare(ndev->num_clks, ndev->clks);
> > +		return ret;
> > +	}
> > +
> > +	neutron_enable_irq(ndev);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct dev_pm_ops neutron_pm_ops = {
> > +	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> pm_runtime_force_resume)
> > +	RUNTIME_PM_OPS(neutron_runtime_suspend,
> neutron_runtime_resume,
> > +NULL) };
> > +
> > +static const struct of_device_id neutron_match_table[] = {
> > +	{ .compatible = "nxp,imx95-neutron" },
> > +	{}
> > +};
> > +
> > +MODULE_DEVICE_TABLE(of, neutron_match_table);
> > +
> > +static struct platform_driver neutron_driver = {
> > +	.probe	= &neutron_probe,
> > +	.remove	= &neutron_remove,
> > +	.driver	= {
> > +		.name		= "neutron",
> > +		.of_match_table	=
> of_match_ptr(neutron_match_table),
> 
> Drop of_match_ptr. You will have (or you have already same as v1) here
> warning.

Will fix. But how do I get to see the warning here? Tried building with
W=1 and OF support disabled but it didn't complain.

Thanks!
Ioana

> 
> > +		.pm		= pm_ptr(&neutron_pm_ops),
> > +	},
> > +};
> Best regards,
> Krzysztof