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[v7,0/5] Add Toshiba Visconti Video Input Interface driver

Message ID 20230714015059.18775-1-yuji2.ishikawa@toshiba.co.jp
Headers show
Series Add Toshiba Visconti Video Input Interface driver | expand

Message

Yuji Ishikawa July 14, 2023, 1:50 a.m. UTC
This series is the Video Input Interface driver
for Toshiba's ARM SoC, Visconti[0].
This provides DT binding documentation,
device driver, documentation and MAINTAINER files.

A visconti VIIF driver instance exposes
1 media control device file and 3 video device files
for a VIIF hardware.
Detailed HW/SW are described in documentation directory.
The VIIF hardware has CSI2 receiver,
image signal processor and DMAC inside.
The subdevice for image signal processor provides
vendor specific V4L2 controls.

The device driver depends on two other drivers under development;
clock framework driver and IOMMU driver.
Corresponding features will be added later.

Best regards,
Yuji

Changelog v2:
- Resend v1 because a patch exceeds size limit.

Changelog v3:
- Add documentation to describe SW and HW
- Adapted to media control framework
- Introduced ISP subdevice, capture device
- Remove private IOCTLs and add vendor specific V4L2 controls
- Change function name avoiding camelcase and uppercase letters

Changelog v4:
- Split patches because a patch exceeds size limit
- fix dt-bindings document
- stop specifying ID numbers for driver instance explicitly at device tree
- use pm_runtime to trigger initialization of HW
  along with open/close of device files.
- add a entry for a header file at MAINTAINERS file

Changelog v5:
- Fix coding style problem in viif.c (patch 2/6)

Changelog v6:
- add register definition of BUS-IF and MPU in dt-bindings
- add CSI2RX subdevice (separeted from ISP subdevice)
- change directory layout (moved to media/platform/toshiba/visconti)
- change source file layout (removed hwd_xxxx.c)
- pointer to userland memory is removed from uAPI parameters
- change register access (from struct style to macro style)
- remove unused macros

Changelog v7:
- remove redundant "bindings" from header and description text
- fix multiline text of "description"
- change "compatible" to "visconti5-viif"
- explicitly define allowed properties for port::endpoint
- remove unused variables
- update kerneldoc comments
- update references to headers

Yuji Ishikawa (5):
  dt-bindings: media: platform: visconti: Add Toshiba Visconti Video
    Input Interface
  media: platform: visconti: Add Toshiba Visconti Video Input Interface
    driver
  media: add V4L2 vendor specific control handlers
  documentation: media: add documentation for Toshiba Visconti Video
    Input Interface driver
  MAINTAINERS: Add entries for Toshiba Visconti Video Input Interface

 .../bindings/media/toshiba,visconti-viif.yaml |  108 +
 .../driver-api/media/drivers/index.rst        |    1 +
 .../media/drivers/visconti-viif.rst           |  462 +++
 MAINTAINERS                                   |    4 +
 drivers/media/platform/Kconfig                |    1 +
 drivers/media/platform/Makefile               |    1 +
 drivers/media/platform/toshiba/Kconfig        |    6 +
 drivers/media/platform/toshiba/Makefile       |    2 +
 .../media/platform/toshiba/visconti/Kconfig   |   18 +
 .../media/platform/toshiba/visconti/Makefile  |    8 +
 .../media/platform/toshiba/visconti/viif.c    |  681 ++++
 .../media/platform/toshiba/visconti/viif.h    |  375 ++
 .../platform/toshiba/visconti/viif_capture.c  | 1485 +++++++
 .../platform/toshiba/visconti/viif_capture.h  |   22 +
 .../platform/toshiba/visconti/viif_common.c   |  199 +
 .../platform/toshiba/visconti/viif_common.h   |   38 +
 .../platform/toshiba/visconti/viif_controls.c | 3407 +++++++++++++++++
 .../platform/toshiba/visconti/viif_controls.h |   18 +
 .../platform/toshiba/visconti/viif_csi2rx.c   |  684 ++++
 .../platform/toshiba/visconti/viif_csi2rx.h   |   24 +
 .../toshiba/visconti/viif_csi2rx_regs.h       |  102 +
 .../platform/toshiba/visconti/viif_isp.c      | 1258 ++++++
 .../platform/toshiba/visconti/viif_isp.h      |   24 +
 .../platform/toshiba/visconti/viif_regs.h     |  716 ++++
 include/uapi/linux/v4l2-controls.h            |    6 +
 include/uapi/linux/visconti_viif.h            | 1800 +++++++++
 26 files changed, 11450 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/toshiba,visconti-viif.yaml
 create mode 100644 Documentation/driver-api/media/drivers/visconti-viif.rst
 create mode 100644 drivers/media/platform/toshiba/Kconfig
 create mode 100644 drivers/media/platform/toshiba/Makefile
 create mode 100644 drivers/media/platform/toshiba/visconti/Kconfig
 create mode 100644 drivers/media/platform/toshiba/visconti/Makefile
 create mode 100644 drivers/media/platform/toshiba/visconti/viif.c
 create mode 100644 drivers/media/platform/toshiba/visconti/viif.h
 create mode 100644 drivers/media/platform/toshiba/visconti/viif_capture.c
 create mode 100644 drivers/media/platform/toshiba/visconti/viif_capture.h
 create mode 100644 drivers/media/platform/toshiba/visconti/viif_common.c
 create mode 100644 drivers/media/platform/toshiba/visconti/viif_common.h
 create mode 100644 drivers/media/platform/toshiba/visconti/viif_controls.c
 create mode 100644 drivers/media/platform/toshiba/visconti/viif_controls.h
 create mode 100644 drivers/media/platform/toshiba/visconti/viif_csi2rx.c
 create mode 100644 drivers/media/platform/toshiba/visconti/viif_csi2rx.h
 create mode 100644 drivers/media/platform/toshiba/visconti/viif_csi2rx_regs.h
 create mode 100644 drivers/media/platform/toshiba/visconti/viif_isp.c
 create mode 100644 drivers/media/platform/toshiba/visconti/viif_isp.h
 create mode 100644 drivers/media/platform/toshiba/visconti/viif_regs.h
 create mode 100644 include/uapi/linux/visconti_viif.h

Comments

Krzysztof Kozlowski July 14, 2023, 8 a.m. UTC | #1
On 14/07/2023 03:50, Yuji Ishikawa wrote:
> Add support to Video Input Interface on Toshiba Visconti ARM SoCs.
> The interface device includes CSI2 Receiver,
> frame grabber, video DMAC and image signal processor.
> 
> A driver instance provides three /dev/videoX device files;
> one for RGB image capture, another one for optional RGB capture
> with different parameters and the last one for RAW capture.
> 

...

> +static int visconti_viif_parse_dt(struct viif_device *viif_dev)
> +{
> +	struct device_node *of = viif_dev->dev->of_node;
> +	struct v4l2_fwnode_endpoint fw_ep;
> +	struct viif_subdev *viif_sd;
> +	struct device_node *ep;
> +	unsigned int i;
> +	int num_ep;
> +	int ret;
> +
> +	memset(&fw_ep, 0, sizeof(struct v4l2_fwnode_endpoint));

Why you cannot initialize it in declaration? = { 0 }?

> +
> +	num_ep = of_graph_get_endpoint_count(of);
> +	if (!num_ep)
> +		return -ENODEV;
> +
> +	ret = visconti_viif_init_async_subdevs(viif_dev, num_ep);
> +	if (ret)
> +		return ret;
> +
> +	for (i = 0; i < num_ep; i++) {
> +		ep = of_graph_get_endpoint_by_regs(of, 0, i);
> +		if (!ep) {
> +			dev_err(viif_dev->dev, "No subdevice connected on endpoint %u.\n", i);
> +			ret = -ENODEV;
> +			goto error_put_node;
> +		}
> +
> +		ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &fw_ep);
> +		if (ret) {
> +			dev_err(viif_dev->dev, "Unable to parse endpoint #%u.\n", i);
> +			goto error_put_node;
> +		}
> +
> +		if (fw_ep.bus_type != V4L2_MBUS_CSI2_DPHY ||
> +		    fw_ep.bus.mipi_csi2.num_data_lanes == 0) {
> +			dev_err(viif_dev->dev, "missing CSI-2 properties in endpoint\n");
> +			ret = -EINVAL;
> +			goto error_put_node;
> +		}
> +
> +		/* Setup the ceu subdevice and the async subdevice. */
> +		viif_sd = &viif_dev->subdevs[i];
> +		INIT_LIST_HEAD(&viif_sd->asd.list);
> +
> +		viif_sd->num_lane = fw_ep.bus.mipi_csi2.num_data_lanes;
> +		viif_sd->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
> +		viif_sd->asd.match.fwnode =
> +			fwnode_graph_get_remote_port_parent(of_fwnode_handle(ep));
> +
> +		viif_dev->asds[i] = &viif_sd->asd;
> +		of_node_put(ep);
> +	}
> +
> +	return num_ep;
> +
> +error_put_node:
> +	of_node_put(ep);
> +	return ret;
> +}
> +
> +static const struct of_device_id visconti_viif_of_table[] = {
> +	{
> +		.compatible = "toshiba,visconti5-viif",
> +	},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, visconti_viif_of_table);
> +
> +#define NUM_IRQS   3
> +#define IRQ_ID_STR "viif"
> +
> +static int visconti_viif_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct viif_device *viif_dev;
> +	dma_addr_t tables_dma;
> +	int ret, i, num_sd;
> +
> +	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(36));
> +	if (ret)
> +		return ret;
> +
> +	viif_dev = devm_kzalloc(dev, sizeof(*viif_dev), GFP_KERNEL);
> +	if (!viif_dev)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, viif_dev);
> +	viif_dev->dev = dev;
> +
> +	spin_lock_init(&viif_dev->regbuf_lock);
> +	mutex_init(&viif_dev->pow_lock);
> +	mutex_init(&viif_dev->stream_lock);
> +
> +	viif_dev->capture_reg = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(viif_dev->capture_reg))
> +		return PTR_ERR(viif_dev->capture_reg);
> +
> +	viif_dev->csi2host_reg = devm_platform_ioremap_resource(pdev, 1);
> +	if (IS_ERR(viif_dev->csi2host_reg))
> +		return PTR_ERR(viif_dev->csi2host_reg);
> +
> +	viif_dev->hwaif_reg = devm_platform_ioremap_resource(pdev, 2);
> +	if (IS_ERR(viif_dev->hwaif_reg))
> +		return PTR_ERR(viif_dev->hwaif_reg);
> +
> +	viif_dev->mpu_reg = devm_platform_ioremap_resource(pdev, 3);
> +	if (IS_ERR(viif_dev->mpu_reg))
> +		return PTR_ERR(viif_dev->mpu_reg);
> +
> +	viif_dev->run_flag_main = false;
> +
> +	for (i = 0; i < NUM_IRQS; i++) {
> +		ret = platform_get_irq(pdev, i);
> +		if (ret < 0) {
> +			dev_err(dev, "failed to acquire irq resource\n");
> +			return ret;

return dev_err_probe()

> +		}
> +		viif_dev->irq[i] = ret;
> +		ret = devm_request_irq(dev, viif_dev->irq[i], visconti_viif_irq, 0, IRQ_ID_STR,
> +				       viif_dev);
> +		if (ret) {
> +			dev_err(dev, "irq request failed\n");

return dev_err_probe()

> +			return ret;
> +		}
> +	}
> +
> +	viif_dev->tables =
> +		dma_alloc_wc(dev, sizeof(struct viif_table_area), &tables_dma, GFP_KERNEL);
> +	if (!viif_dev->tables) {
> +		dev_err(dev, "dma_alloc_wc failed\n");

Are you sure DMA memory allocation errors shall be printed?

> +		return -ENOMEM;
> +	}
> +	viif_dev->tables_dma = (struct viif_table_area *)tables_dma;
> +
> +	/* power control */

Drop the comment, it is useless.

> +	pm_runtime_enable(dev);
> +
> +	/* build media_dev */
> +	viif_dev->media_dev.hw_revision = 0;
> +	strscpy(viif_dev->media_dev.model, VIIF_DRIVER_NAME, sizeof(viif_dev->media_dev.model));
> +	viif_dev->media_dev.dev = dev;
> +	/* TODO: platform:visconti-viif-0,1,2,3 for each VIIF driver instance */
> +	snprintf(viif_dev->media_dev.bus_info, sizeof(viif_dev->media_dev.bus_info), "%s-0",
> +		 VIIF_BUS_INFO_BASE);
> +	media_device_init(&viif_dev->media_dev);
> +
> +	/* build v4l2_dev */
> +	viif_dev->v4l2_dev.mdev = &viif_dev->media_dev;
> +	ret = v4l2_device_register(dev, &viif_dev->v4l2_dev);
> +	if (ret)
> +		goto error_dma_free;
> +
> +	ret = media_device_register(&viif_dev->media_dev);
> +	if (ret) {
> +		dev_err(dev, "Failed to register media device: %d\n", ret);
> +		goto error_v4l2_unregister;

dev_err_probe

> +	}
> +
> +	ret = visconti_viif_csi2rx_register(viif_dev);
> +	if (ret) {
> +		dev_err(dev, "failed to register csi2rx sub node: %d\n", ret);

dev_err_probe


> +		goto error_media_unregister;
> +	}
> +
> +	ret = visconti_viif_isp_register(viif_dev);
> +	if (ret) {
> +		dev_err(dev, "failed to register isp sub node: %d\n", ret);

dev_err_probe


> +		goto error_media_unregister;
> +	}
> +	ret = visconti_viif_capture_register(viif_dev);
> +	if (ret) {
> +		dev_err(dev, "failed to register capture node: %d\n", ret);

dev_err_probe

> +		goto error_media_unregister;
> +	}
> +
> +	/* handle subdevices in device tree */
> +	num_sd = visconti_viif_parse_dt(viif_dev);
> +	if (ret < 0) {
> +		ret = num_sd;

ret = dev_err_probe

> +		goto error_media_unregister;
> +	}
> +
> +	viif_dev->notifier.v4l2_dev = &viif_dev->v4l2_dev;
> +	v4l2_async_nf_init(&viif_dev->notifier);
> +	for (i = 0; i < num_sd; i++)
> +		__v4l2_async_nf_add_subdev(&viif_dev->notifier, viif_dev->asds[i]);
> +	viif_dev->notifier.ops = &viif_notify_ops;
> +	ret = v4l2_async_nf_register(&viif_dev->v4l2_dev, &viif_dev->notifier);
> +	if (ret)
> +		goto error_media_unregister;
> +
> +	viif_dev->wq = create_workqueue("visconti-viif");
> +	if (!viif_dev->wq)
> +		return -ENOMEM;

No error cleanup?

> +	INIT_WORK(&viif_dev->work, visconti_viif_wthread_l1info);
> +
> +	return 0;
> +
> +error_media_unregister:
> +	media_device_unregister(&viif_dev->media_dev);
> +error_v4l2_unregister:
> +	v4l2_device_unregister(&viif_dev->v4l2_dev);
> +error_dma_free:
> +	pm_runtime_disable(dev);
> +	dma_free_wc(&pdev->dev, sizeof(struct viif_table_area), viif_dev->tables,
> +		    (dma_addr_t)viif_dev->tables_dma);
> +	return ret;
> +}
> +
> +static int visconti_viif_remove(struct platform_device *pdev)
> +{
> +	struct viif_device *viif_dev = platform_get_drvdata(pdev);
> +
> +	destroy_workqueue(viif_dev->wq);
> +	visconti_viif_isp_unregister(viif_dev);
> +	visconti_viif_capture_unregister(viif_dev);
> +	v4l2_async_nf_unregister(&viif_dev->notifier);

Why these three are not called in probe error paths?

> +	media_device_unregister(&viif_dev->media_dev);
> +	v4l2_device_unregister(&viif_dev->v4l2_dev);
> +	pm_runtime_disable(&pdev->dev);
> +	dma_free_wc(&pdev->dev, sizeof(struct viif_table_area), viif_dev->tables,
> +		    (dma_addr_t)viif_dev->tables_dma);
> +
> +	return 0;
> +}
> +
> +static int visconti_viif_runtime_suspend(struct device *dev)
> +{
> +	/* This callback is kicked when the last device-file is closed */
> +	struct viif_device *viif_dev = dev_get_drvdata(dev);
> +
> +	mutex_lock(&viif_dev->pow_lock);

Why?

> +	visconti_viif_hw_off(viif_dev);
> +	mutex_unlock(&viif_dev->pow_lock);
> +
> +	return 0;
> +}
> +
> +static int visconti_viif_runtime_resume(struct device *dev)
> +{
> +	/* This callback is kicked when the first device-file is opened */
> +	struct viif_device *viif_dev = dev_get_drvdata(dev);
> +
> +	viif_dev->rawpack_mode = (u32)VIIF_RAWPACK_DISABLE;
> +
> +	mutex_lock(&viif_dev->pow_lock);

Why?

> +
> +	/* Initialize HWD driver */
> +	visconti_viif_hw_on(viif_dev);
> +
> +	/* VSYNC mask setting of MAIN unit */
> +	viif_main_vsync_set_irq_mask(viif_dev, MASK_INT_M_SYNC_MASK_SET);
> +
> +	/* STATUS error mask setting of MAIN unit */
> +	viif_main_status_err_set_irq_mask(viif_dev, MASK_INT_M_DELAY_INT_ERROR);
> +
> +	/* VSYNC mask settings of SUB unit */
> +	viif_sub_vsync_set_irq_mask(viif_dev, MASK_INT_S_SYNC_MASK_SET);
> +
> +	/* STATUS error mask setting(unmask) of SUB unit */
> +	viif_sub_status_err_set_irq_mask(viif_dev,
> +					 MASK_INT_S_RESERVED_SET | MASK_INT_S_DELAY_INT_ERROR);
> +
> +	mutex_unlock(&viif_dev->pow_lock);
> +
> +	return 0;
> +}
> +

Best regards,
Krzysztof
Yuji Ishikawa July 25, 2023, 6:10 a.m. UTC | #2
Helo Krzysztof
Thank you for your review comments.

> -----Original Message-----
> From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Sent: Friday, July 14, 2023 5:00 PM
> To: ishikawa yuji(石川 悠司 ○RDC□AITC○EA開)
> <yuji2.ishikawa@toshiba.co.jp>; Hans Verkuil <hverkuil@xs4all.nl>; Sakari
> Ailus <sakari.ailus@iki.fi>; Laurent Pinchart
> <laurent.pinchart@ideasonboard.com>; Mauro Carvalho Chehab
> <mchehab@kernel.org>; Rob Herring <robh+dt@kernel.org>; Krzysztof
> Kozlowski <krzysztof.kozlowski+dt@linaro.org>; Conor Dooley
> <conor+dt@kernel.org>; iwamatsu nobuhiro(岩松 信洋 ○DITC□DIT○
> OST) <nobuhiro1.iwamatsu@toshiba.co.jp>; Mark Brown
> <broonie@kernel.org>
> Cc: linux-media@vger.kernel.org; devicetree@vger.kernel.org;
> linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v7 2/5] media: platform: visconti: Add Toshiba Visconti
> Video Input Interface driver
> 
> On 14/07/2023 03:50, Yuji Ishikawa wrote:
> > Add support to Video Input Interface on Toshiba Visconti ARM SoCs.
> > The interface device includes CSI2 Receiver, frame grabber, video DMAC
> > and image signal processor.
> >
> > A driver instance provides three /dev/videoX device files; one for RGB
> > image capture, another one for optional RGB capture with different
> > parameters and the last one for RAW capture.
> >
> 
> ...
> 
> > +static int visconti_viif_parse_dt(struct viif_device *viif_dev) {
> > +	struct device_node *of = viif_dev->dev->of_node;
> > +	struct v4l2_fwnode_endpoint fw_ep;
> > +	struct viif_subdev *viif_sd;
> > +	struct device_node *ep;
> > +	unsigned int i;
> > +	int num_ep;
> > +	int ret;
> > +
> > +	memset(&fw_ep, 0, sizeof(struct v4l2_fwnode_endpoint));
> 
> Why you cannot initialize it in declaration? = { 0 }?
> 

I'll initialize it at declaration.
Same for similar cases.

> > +
> > +	num_ep = of_graph_get_endpoint_count(of);
> > +	if (!num_ep)
> > +		return -ENODEV;
> > +
> > +	ret = visconti_viif_init_async_subdevs(viif_dev, num_ep);
> > +	if (ret)
> > +		return ret;
> > +
> > +	for (i = 0; i < num_ep; i++) {
> > +		ep = of_graph_get_endpoint_by_regs(of, 0, i);
> > +		if (!ep) {
> > +			dev_err(viif_dev->dev, "No subdevice connected on
> endpoint %u.\n", i);
> > +			ret = -ENODEV;
> > +			goto error_put_node;
> > +		}
> > +
> > +		ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep),
> &fw_ep);
> > +		if (ret) {
> > +			dev_err(viif_dev->dev, "Unable to parse endpoint
> #%u.\n", i);
> > +			goto error_put_node;
> > +		}
> > +
> > +		if (fw_ep.bus_type != V4L2_MBUS_CSI2_DPHY ||
> > +		    fw_ep.bus.mipi_csi2.num_data_lanes == 0) {
> > +			dev_err(viif_dev->dev, "missing CSI-2 properties in
> endpoint\n");
> > +			ret = -EINVAL;
> > +			goto error_put_node;
> > +		}
> > +
> > +		/* Setup the ceu subdevice and the async subdevice. */
> > +		viif_sd = &viif_dev->subdevs[i];
> > +		INIT_LIST_HEAD(&viif_sd->asd.list);
> > +
> > +		viif_sd->num_lane = fw_ep.bus.mipi_csi2.num_data_lanes;
> > +		viif_sd->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
> > +		viif_sd->asd.match.fwnode =
> > +
> 	fwnode_graph_get_remote_port_parent(of_fwnode_handle(ep));
> > +
> > +		viif_dev->asds[i] = &viif_sd->asd;
> > +		of_node_put(ep);
> > +	}
> > +
> > +	return num_ep;
> > +
> > +error_put_node:
> > +	of_node_put(ep);
> > +	return ret;
> > +}
> > +
> > +static const struct of_device_id visconti_viif_of_table[] = {
> > +	{
> > +		.compatible = "toshiba,visconti5-viif",
> > +	},
> > +	{},
> > +};
> > +MODULE_DEVICE_TABLE(of, visconti_viif_of_table);
> > +
> > +#define NUM_IRQS   3
> > +#define IRQ_ID_STR "viif"
> > +
> > +static int visconti_viif_probe(struct platform_device *pdev) {
> > +	struct device *dev = &pdev->dev;
> > +	struct viif_device *viif_dev;
> > +	dma_addr_t tables_dma;
> > +	int ret, i, num_sd;
> > +
> > +	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(36));
> > +	if (ret)
> > +		return ret;
> > +
> > +	viif_dev = devm_kzalloc(dev, sizeof(*viif_dev), GFP_KERNEL);
> > +	if (!viif_dev)
> > +		return -ENOMEM;
> > +
> > +	platform_set_drvdata(pdev, viif_dev);
> > +	viif_dev->dev = dev;
> > +
> > +	spin_lock_init(&viif_dev->regbuf_lock);
> > +	mutex_init(&viif_dev->pow_lock);
> > +	mutex_init(&viif_dev->stream_lock);
> > +
> > +	viif_dev->capture_reg = devm_platform_ioremap_resource(pdev, 0);
> > +	if (IS_ERR(viif_dev->capture_reg))
> > +		return PTR_ERR(viif_dev->capture_reg);
> > +
> > +	viif_dev->csi2host_reg = devm_platform_ioremap_resource(pdev, 1);
> > +	if (IS_ERR(viif_dev->csi2host_reg))
> > +		return PTR_ERR(viif_dev->csi2host_reg);
> > +
> > +	viif_dev->hwaif_reg = devm_platform_ioremap_resource(pdev, 2);
> > +	if (IS_ERR(viif_dev->hwaif_reg))
> > +		return PTR_ERR(viif_dev->hwaif_reg);
> > +
> > +	viif_dev->mpu_reg = devm_platform_ioremap_resource(pdev, 3);
> > +	if (IS_ERR(viif_dev->mpu_reg))
> > +		return PTR_ERR(viif_dev->mpu_reg);
> > +
> > +	viif_dev->run_flag_main = false;
> > +
> > +	for (i = 0; i < NUM_IRQS; i++) {
> > +		ret = platform_get_irq(pdev, i);
> > +		if (ret < 0) {
> > +			dev_err(dev, "failed to acquire irq resource\n");
> > +			return ret;
> 
> return dev_err_probe()
> 

I'll use dev_err_probe().
Same for other suggestions.

> > +		}
> > +		viif_dev->irq[i] = ret;
> > +		ret = devm_request_irq(dev, viif_dev->irq[i], visconti_viif_irq, 0,
> IRQ_ID_STR,
> > +				       viif_dev);
> > +		if (ret) {
> > +			dev_err(dev, "irq request failed\n");
> 
> return dev_err_probe()
> 

I'll use dev_err_probe().

> > +			return ret;
> > +		}
> > +	}
> > +
> > +	viif_dev->tables =
> > +		dma_alloc_wc(dev, sizeof(struct viif_table_area), &tables_dma,
> GFP_KERNEL);
> > +	if (!viif_dev->tables) {
> > +		dev_err(dev, "dma_alloc_wc failed\n");
> 
> Are you sure DMA memory allocation errors shall be printed?
> 

Printing this error is useless for users in general?
If so, I'll drop this debug output.

> > +		return -ENOMEM;
> > +	}
> > +	viif_dev->tables_dma = (struct viif_table_area *)tables_dma;
> > +
> > +	/* power control */
> 
> Drop the comment, it is useless.
> 

I'll drop the comment

> > +	pm_runtime_enable(dev);
> > +
> > +	/* build media_dev */
> > +	viif_dev->media_dev.hw_revision = 0;
> > +	strscpy(viif_dev->media_dev.model, VIIF_DRIVER_NAME,
> sizeof(viif_dev->media_dev.model));
> > +	viif_dev->media_dev.dev = dev;
> > +	/* TODO: platform:visconti-viif-0,1,2,3 for each VIIF driver instance */
> > +	snprintf(viif_dev->media_dev.bus_info,
> sizeof(viif_dev->media_dev.bus_info), "%s-0",
> > +		 VIIF_BUS_INFO_BASE);
> > +	media_device_init(&viif_dev->media_dev);
> > +
> > +	/* build v4l2_dev */
> > +	viif_dev->v4l2_dev.mdev = &viif_dev->media_dev;
> > +	ret = v4l2_device_register(dev, &viif_dev->v4l2_dev);
> > +	if (ret)
> > +		goto error_dma_free;
> > +
> > +	ret = media_device_register(&viif_dev->media_dev);
> > +	if (ret) {
> > +		dev_err(dev, "Failed to register media device: %d\n", ret);
> > +		goto error_v4l2_unregister;
> 
> dev_err_probe
> 

I'll use dev_err_probe().

> > +	}
> > +
> > +	ret = visconti_viif_csi2rx_register(viif_dev);
> > +	if (ret) {
> > +		dev_err(dev, "failed to register csi2rx sub node: %d\n", ret);
> 
> dev_err_probe
> 

I'll use dev_err_probe().

> > +		goto error_media_unregister;
> > +	}
> > +
> > +	ret = visconti_viif_isp_register(viif_dev);
> > +	if (ret) {
> > +		dev_err(dev, "failed to register isp sub node: %d\n", ret);
> 
> dev_err_probe
> 

I'll use dev_err_probe().

> > +		goto error_media_unregister;
> > +	}
> > +	ret = visconti_viif_capture_register(viif_dev);
> > +	if (ret) {
> > +		dev_err(dev, "failed to register capture node: %d\n", ret);
> 
> dev_err_probe
> 

I'll use dev_err_probe().

> > +		goto error_media_unregister;
> > +	}
> > +
> > +	/* handle subdevices in device tree */
> > +	num_sd = visconti_viif_parse_dt(viif_dev);
> > +	if (ret < 0) {
> > +		ret = num_sd;
> 
> ret = dev_err_probe
> 

I'll use dev_err_probe().

> > +		goto error_media_unregister;
> > +	}
> > +
> > +	viif_dev->notifier.v4l2_dev = &viif_dev->v4l2_dev;
> > +	v4l2_async_nf_init(&viif_dev->notifier);
> > +	for (i = 0; i < num_sd; i++)
> > +		__v4l2_async_nf_add_subdev(&viif_dev->notifier,
> viif_dev->asds[i]);
> > +	viif_dev->notifier.ops = &viif_notify_ops;
> > +	ret = v4l2_async_nf_register(&viif_dev->v4l2_dev, &viif_dev->notifier);
> > +	if (ret)
> > +		goto error_media_unregister;
> > +
> > +	viif_dev->wq = create_workqueue("visconti-viif");
> > +	if (!viif_dev->wq)
> > +		return -ENOMEM;
> 
> No error cleanup?
> 

There should be. I'll add cleanup operations.

> > +	INIT_WORK(&viif_dev->work, visconti_viif_wthread_l1info);
> > +
> > +	return 0;
> > +
> > +error_media_unregister:
> > +	media_device_unregister(&viif_dev->media_dev);
> > +error_v4l2_unregister:
> > +	v4l2_device_unregister(&viif_dev->v4l2_dev);
> > +error_dma_free:
> > +	pm_runtime_disable(dev);
> > +	dma_free_wc(&pdev->dev, sizeof(struct viif_table_area),
> viif_dev->tables,
> > +		    (dma_addr_t)viif_dev->tables_dma);
> > +	return ret;
> > +}
> > +
> > +static int visconti_viif_remove(struct platform_device *pdev) {
> > +	struct viif_device *viif_dev = platform_get_drvdata(pdev);
> > +
> > +	destroy_workqueue(viif_dev->wq);
> > +	visconti_viif_isp_unregister(viif_dev);
> > +	visconti_viif_capture_unregister(viif_dev);
> > +	v4l2_async_nf_unregister(&viif_dev->notifier);
> 
> Why these three are not called in probe error paths?
> 

There should be. I'll add calls of unregister functions.

> > +	media_device_unregister(&viif_dev->media_dev);
> > +	v4l2_device_unregister(&viif_dev->v4l2_dev);
> > +	pm_runtime_disable(&pdev->dev);
> > +	dma_free_wc(&pdev->dev, sizeof(struct viif_table_area),
> viif_dev->tables,
> > +		    (dma_addr_t)viif_dev->tables_dma);
> > +
> > +	return 0;
> > +}
> > +
> > +static int visconti_viif_runtime_suspend(struct device *dev) {
> > +	/* This callback is kicked when the last device-file is closed */
> > +	struct viif_device *viif_dev = dev_get_drvdata(dev);
> > +
> > +	mutex_lock(&viif_dev->pow_lock);
> 
> Why?
> 

I'll drop this mutex call.

I was not sure if runtime_suspend() and runtime_resume() are not processed at the same time.
Now I understand callbacks are mutually exclusive (as documented in runtime_pm.rst).

> > +	visconti_viif_hw_off(viif_dev);
> > +	mutex_unlock(&viif_dev->pow_lock);
> > +
> > +	return 0;
> > +}
> > +
> > +static int visconti_viif_runtime_resume(struct device *dev) {
> > +	/* This callback is kicked when the first device-file is opened */
> > +	struct viif_device *viif_dev = dev_get_drvdata(dev);
> > +
> > +	viif_dev->rawpack_mode = (u32)VIIF_RAWPACK_DISABLE;
> > +
> > +	mutex_lock(&viif_dev->pow_lock);
> 
> Why?
> 

I'll drop this mutex call.

> > +
> > +	/* Initialize HWD driver */
> > +	visconti_viif_hw_on(viif_dev);
> > +
> > +	/* VSYNC mask setting of MAIN unit */
> > +	viif_main_vsync_set_irq_mask(viif_dev,
> MASK_INT_M_SYNC_MASK_SET);
> > +
> > +	/* STATUS error mask setting of MAIN unit */
> > +	viif_main_status_err_set_irq_mask(viif_dev,
> > +MASK_INT_M_DELAY_INT_ERROR);
> > +
> > +	/* VSYNC mask settings of SUB unit */
> > +	viif_sub_vsync_set_irq_mask(viif_dev,
> MASK_INT_S_SYNC_MASK_SET);
> > +
> > +	/* STATUS error mask setting(unmask) of SUB unit */
> > +	viif_sub_status_err_set_irq_mask(viif_dev,
> > +					 MASK_INT_S_RESERVED_SET |
> MASK_INT_S_DELAY_INT_ERROR);
> > +
> > +	mutex_unlock(&viif_dev->pow_lock);
> > +
> > +	return 0;
> > +}
> > +
> 
> Best regards,
> Krzysztof

Best regards,
Yuji
Hans Verkuil Aug. 21, 2023, 12:28 p.m. UTC | #3
On 14/07/2023 03:50, Yuji Ishikawa wrote:
> Add support to Image Signal Processors of Visconti's Video Input Interface.
> This patch adds vendor specific compound controls
> to configure the image signal processor.
> 
> Signed-off-by: Yuji Ishikawa <yuji2.ishikawa@toshiba.co.jp>
> ---
> Changelog v2:
> - Resend v1 because a patch exceeds size limit.
> 
> Changelog v3:
> - Adapted to media control framework
> - Introduced ISP subdevice, capture device
> - Remove private IOCTLs and add vendor specific V4L2 controls
> - Change function name avoiding camelcase and uppercase letters
> 
> Changelog v4:
> - Split patches because the v3 patch exceeds size limit
> - Stop using ID number to identify driver instance:
>   - Use dynamically allocated structure to hold HW specific context,
>     instead of static one.
>   - Call HW layer functions with the context structure instead of ID number
> 
> Changelog v5:
> - no change
> 
> Changelog v6:
> - remove unused macros
> - removed hwd_ and HWD_ prefix
> - update source code documentation
> - Suggestion from Hans Verkuil
>   - pointer to userland memory is removed from uAPI arguments
>     - style of structure is now "nested" instead of "chained by pointer";
>   - use div64_u64 for 64bit division
>   - vendor specific controls support TRY_EXT_CTRLS
>   - add READ_ONLY flag to GET_CALIBRATION_STATUS control and similar ones
>   - human friendry control names for vendor specific controls
>   - add initial value to each vendor specific control
>   - GET_LAST_CAPTURE_STATUS control is updated asyncnously from workqueue
>   - remove EXECUTE_ON_WRITE flag of vendor specific control
>   - uAPI: return value of GET_CALIBRATION_STATUS follows common rules of error codes
>   - applied v4l2-compliance
> - Suggestion from Sakari Ailus
>   - use div64_u64 for 64bit division
>   - update copyright's year
>   - remove redandunt cast
>   - use bool instead of HWD_VIIF_ENABLE/DISABLE
>   - simplify comparison to 0
>   - simplify statements with trigram operator
>   - remove redundant local variables
>   - use general integer types instead of u32/s32
> - Suggestion from Laurent Pinchart
>   - moved VIIF driver to driver/platform/toshiba/visconti
>   - change register access: struct-style to macro-style
>   - remove unused type definitions
>   - define enums instead of successive macro constants
>   - remove redundant parenthesis of macro constant
>   - embed struct hwd_res into struct viif_device
>   - use xxx_dma instead of xxx_paddr for variable names of IOVA
>   - literal value: just 0 instead of 0x0
>   - use literal 1 or 0 instead of HWD_VIIF_ENABLE, DISABLE for register access
>   - use true or false instead of HWD_VIIF_ENABLE, DISABLE for function calls
>   - uAPI: return value of GET_CALIBRATION_STATUS follows common rules of error codes
> 
> Changelog v7:
> - remove unused variables
> - split long statements which have multiple logical-OR and trigram operators
> 
>  .../media/platform/toshiba/visconti/Makefile  |    2 +-
>  .../media/platform/toshiba/visconti/viif.c    |   10 +-
>  .../platform/toshiba/visconti/viif_controls.c | 3407 +++++++++++++++++
>  .../platform/toshiba/visconti/viif_controls.h |   18 +
>  .../platform/toshiba/visconti/viif_isp.c      |   15 +-
>  5 files changed, 3435 insertions(+), 17 deletions(-)
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_controls.c
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_controls.h
> 
> diff --git a/drivers/media/platform/toshiba/visconti/Makefile b/drivers/media/platform/toshiba/visconti/Makefile
> index 5f2f9199c..a28e6fa84 100644
> --- a/drivers/media/platform/toshiba/visconti/Makefile
> +++ b/drivers/media/platform/toshiba/visconti/Makefile
> @@ -3,6 +3,6 @@
>  # Makefile for the Visconti video input device driver
>  #
>  
> -visconti-viif-objs = viif.o viif_capture.o viif_isp.o viif_csi2rx.o viif_common.o
> +visconti-viif-objs = viif.o viif_capture.o viif_controls.o viif_isp.o viif_csi2rx.o viif_common.o
>  
>  obj-$(CONFIG_VIDEO_VISCONTI_VIIF) += visconti-viif.o
> diff --git a/drivers/media/platform/toshiba/visconti/viif.c b/drivers/media/platform/toshiba/visconti/viif.c
> index c07dc2626..1b3d61abf 100644
> --- a/drivers/media/platform/toshiba/visconti/viif.c
> +++ b/drivers/media/platform/toshiba/visconti/viif.c
> @@ -18,6 +18,7 @@
>  
>  #include "viif.h"
>  #include "viif_capture.h"
> +#include "viif_controls.h"
>  #include "viif_csi2rx.h"
>  #include "viif_common.h"
>  #include "viif_isp.h"
> @@ -178,12 +179,9 @@ static struct viif_subdev *to_viif_subdev(struct v4l2_async_subdev *asd)
>  /* before a userland capture application is trigered by vb2_buffer_done() */
>  static void visconti_viif_wthread_l1info(struct work_struct *work)
>  {
> -	/* called function is implemented by the next patch */
> -/*
> - *	struct viif_device *viif_dev = container_of(work, struct viif_device, work);
> - *
> - *	visconti_viif_save_l1_info(viif_dev);
> - */
> +	struct viif_device *viif_dev = container_of(work, struct viif_device, work);
> +
> +	visconti_viif_save_l1_info(viif_dev);
>  }
>  
>  static void viif_vsync_irq_handler_w_isp(struct viif_device *viif_dev)
> diff --git a/drivers/media/platform/toshiba/visconti/viif_controls.c b/drivers/media/platform/toshiba/visconti/viif_controls.c
> new file mode 100644
> index 000000000..3cf10e15c
> --- /dev/null
> +++ b/drivers/media/platform/toshiba/visconti/viif_controls.c
> @@ -0,0 +1,3407 @@

<snip>

> +static int visconti_viif_isp_try_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	struct viif_device *viif_dev = ctrl->priv;
> +
> +	switch (ctrl->id) {
> +	case V4L2_CID_VISCONTI_VIIF_MAIN_SET_RAWPACK_MODE:
> +		return viif_main_set_rawpack_mode_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_INPUT_MODE:
> +		return viif_l1_set_input_mode_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_RGB_TO_Y_COEF:
> +		return viif_l1_set_rgb_to_y_coef_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_AG_MODE:
> +		return viif_l1_set_ag_mode_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_AG:
> +		return 0; //no need to check
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_HDRE:
> +		return viif_l1_set_hdre_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_IMG_EXTRACTION:
> +		return viif_l1_set_img_extraction_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_DPC:
> +		return viif_l1_set_dpc_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_PRESET_WHITE_BALANCE:
> +		return viif_l1_set_preset_white_balance_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_RAW_COLOR_NOISE_REDUCTION:
> +		return viif_l1_set_raw_color_noise_reduction_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_HDRS:
> +		return viif_l1_set_hdrs_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_BLACK_LEVEL_CORRECTION:
> +		return viif_l1_set_black_level_correction_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_LSC:
> +		return viif_l1_set_lsc_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_MAIN_PROCESS:
> +		return viif_l1_set_main_process_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_AWB:
> +		return viif_l1_set_awb_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_LOCK_AWB_GAIN:
> +		return 0;
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_HDRC:
> +		return viif_l1_set_hdrc_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_HDRC_LTM:
> +		return viif_l1_set_hdrc_ltm_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_GAMMA:
> +		return viif_l1_set_gamma_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_IMG_QUALITY_ADJUSTMENT:
> +		return viif_l1_set_img_quality_adjustment_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_AVG_LUM_GENERATION:
> +		return viif_l1_set_avg_lum_generation_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L2_SET_UNDIST:
> +		return viif_l2_set_undist_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L2_SET_ROI:
> +		return viif_l2_set_roi_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_ISP_L2_SET_GAMMA:
> +		return viif_l2_set_gamma_try(viif_dev, ctrl->p_new.p);
> +	case V4L2_CID_VISCONTI_VIIF_GET_LAST_CAPTURE_STATUS:
> +		return 0;
> +	default:
> +		pr_info("unknown_ctrl:t: id=%08X val=%d", ctrl->id, ctrl->val);
> +		break;
> +	}
> +	return -EINVAL;
> +}
> +
> +static int visconti_viif_isp_set_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	struct viif_device *viif_dev = ctrl->priv;
> +	int ret;
> +
> +	pr_info("isp_set_ctrl: %s", ctrl->name);

Don't use pr_info for what is just a debug message! Either drop it, or
replace it with dev_dbg.

> +	if (pm_runtime_status_suspended(viif_dev->dev)) {
> +		pr_info("warning: visconti viif HW is not powered");

And here pr_info is used for a warning, so shouldn't this be dev_warn?

I see pr_info being used in a lot of places where it doesn't belong and
would just spam the kernel log.

Something to go through for v8.

Regards,

	Hans
Laurent Pinchart Aug. 21, 2023, 12:33 p.m. UTC | #4
On Mon, Aug 21, 2023 at 02:28:11PM +0200, Hans Verkuil wrote:
> On 14/07/2023 03:50, Yuji Ishikawa wrote:
> > Add support to Image Signal Processors of Visconti's Video Input Interface.
> > This patch adds vendor specific compound controls
> > to configure the image signal processor.
> > 
> > Signed-off-by: Yuji Ishikawa <yuji2.ishikawa@toshiba.co.jp>
> > ---
> > Changelog v2:
> > - Resend v1 because a patch exceeds size limit.
> > 
> > Changelog v3:
> > - Adapted to media control framework
> > - Introduced ISP subdevice, capture device
> > - Remove private IOCTLs and add vendor specific V4L2 controls
> > - Change function name avoiding camelcase and uppercase letters
> > 
> > Changelog v4:
> > - Split patches because the v3 patch exceeds size limit
> > - Stop using ID number to identify driver instance:
> >   - Use dynamically allocated structure to hold HW specific context,
> >     instead of static one.
> >   - Call HW layer functions with the context structure instead of ID number
> > 
> > Changelog v5:
> > - no change
> > 
> > Changelog v6:
> > - remove unused macros
> > - removed hwd_ and HWD_ prefix
> > - update source code documentation
> > - Suggestion from Hans Verkuil
> >   - pointer to userland memory is removed from uAPI arguments
> >     - style of structure is now "nested" instead of "chained by pointer";
> >   - use div64_u64 for 64bit division
> >   - vendor specific controls support TRY_EXT_CTRLS
> >   - add READ_ONLY flag to GET_CALIBRATION_STATUS control and similar ones
> >   - human friendry control names for vendor specific controls
> >   - add initial value to each vendor specific control
> >   - GET_LAST_CAPTURE_STATUS control is updated asyncnously from workqueue
> >   - remove EXECUTE_ON_WRITE flag of vendor specific control
> >   - uAPI: return value of GET_CALIBRATION_STATUS follows common rules of error codes
> >   - applied v4l2-compliance
> > - Suggestion from Sakari Ailus
> >   - use div64_u64 for 64bit division
> >   - update copyright's year
> >   - remove redandunt cast
> >   - use bool instead of HWD_VIIF_ENABLE/DISABLE
> >   - simplify comparison to 0
> >   - simplify statements with trigram operator
> >   - remove redundant local variables
> >   - use general integer types instead of u32/s32
> > - Suggestion from Laurent Pinchart
> >   - moved VIIF driver to driver/platform/toshiba/visconti
> >   - change register access: struct-style to macro-style
> >   - remove unused type definitions
> >   - define enums instead of successive macro constants
> >   - remove redundant parenthesis of macro constant
> >   - embed struct hwd_res into struct viif_device
> >   - use xxx_dma instead of xxx_paddr for variable names of IOVA
> >   - literal value: just 0 instead of 0x0
> >   - use literal 1 or 0 instead of HWD_VIIF_ENABLE, DISABLE for register access
> >   - use true or false instead of HWD_VIIF_ENABLE, DISABLE for function calls
> >   - uAPI: return value of GET_CALIBRATION_STATUS follows common rules of error codes
> > 
> > Changelog v7:
> > - remove unused variables
> > - split long statements which have multiple logical-OR and trigram operators
> > 
> >  .../media/platform/toshiba/visconti/Makefile  |    2 +-
> >  .../media/platform/toshiba/visconti/viif.c    |   10 +-
> >  .../platform/toshiba/visconti/viif_controls.c | 3407 +++++++++++++++++
> >  .../platform/toshiba/visconti/viif_controls.h |   18 +
> >  .../platform/toshiba/visconti/viif_isp.c      |   15 +-
> >  5 files changed, 3435 insertions(+), 17 deletions(-)
> >  create mode 100644 drivers/media/platform/toshiba/visconti/viif_controls.c
> >  create mode 100644 drivers/media/platform/toshiba/visconti/viif_controls.h
> > 
> > diff --git a/drivers/media/platform/toshiba/visconti/Makefile b/drivers/media/platform/toshiba/visconti/Makefile
> > index 5f2f9199c..a28e6fa84 100644
> > --- a/drivers/media/platform/toshiba/visconti/Makefile
> > +++ b/drivers/media/platform/toshiba/visconti/Makefile
> > @@ -3,6 +3,6 @@
> >  # Makefile for the Visconti video input device driver
> >  #
> >  
> > -visconti-viif-objs = viif.o viif_capture.o viif_isp.o viif_csi2rx.o viif_common.o
> > +visconti-viif-objs = viif.o viif_capture.o viif_controls.o viif_isp.o viif_csi2rx.o viif_common.o
> >  
> >  obj-$(CONFIG_VIDEO_VISCONTI_VIIF) += visconti-viif.o
> > diff --git a/drivers/media/platform/toshiba/visconti/viif.c b/drivers/media/platform/toshiba/visconti/viif.c
> > index c07dc2626..1b3d61abf 100644
> > --- a/drivers/media/platform/toshiba/visconti/viif.c
> > +++ b/drivers/media/platform/toshiba/visconti/viif.c
> > @@ -18,6 +18,7 @@
> >  
> >  #include "viif.h"
> >  #include "viif_capture.h"
> > +#include "viif_controls.h"
> >  #include "viif_csi2rx.h"
> >  #include "viif_common.h"
> >  #include "viif_isp.h"
> > @@ -178,12 +179,9 @@ static struct viif_subdev *to_viif_subdev(struct v4l2_async_subdev *asd)
> >  /* before a userland capture application is trigered by vb2_buffer_done() */
> >  static void visconti_viif_wthread_l1info(struct work_struct *work)
> >  {
> > -	/* called function is implemented by the next patch */
> > -/*
> > - *	struct viif_device *viif_dev = container_of(work, struct viif_device, work);
> > - *
> > - *	visconti_viif_save_l1_info(viif_dev);
> > - */
> > +	struct viif_device *viif_dev = container_of(work, struct viif_device, work);
> > +
> > +	visconti_viif_save_l1_info(viif_dev);
> >  }
> >  
> >  static void viif_vsync_irq_handler_w_isp(struct viif_device *viif_dev)
> > diff --git a/drivers/media/platform/toshiba/visconti/viif_controls.c b/drivers/media/platform/toshiba/visconti/viif_controls.c
> > new file mode 100644
> > index 000000000..3cf10e15c
> > --- /dev/null
> > +++ b/drivers/media/platform/toshiba/visconti/viif_controls.c
> > @@ -0,0 +1,3407 @@
> 
> <snip>
> 
> > +static int visconti_viif_isp_try_ctrl(struct v4l2_ctrl *ctrl)
> > +{
> > +	struct viif_device *viif_dev = ctrl->priv;
> > +
> > +	switch (ctrl->id) {
> > +	case V4L2_CID_VISCONTI_VIIF_MAIN_SET_RAWPACK_MODE:
> > +		return viif_main_set_rawpack_mode_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_INPUT_MODE:
> > +		return viif_l1_set_input_mode_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_RGB_TO_Y_COEF:
> > +		return viif_l1_set_rgb_to_y_coef_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_AG_MODE:
> > +		return viif_l1_set_ag_mode_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_AG:
> > +		return 0; //no need to check
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_HDRE:
> > +		return viif_l1_set_hdre_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_IMG_EXTRACTION:
> > +		return viif_l1_set_img_extraction_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_DPC:
> > +		return viif_l1_set_dpc_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_PRESET_WHITE_BALANCE:
> > +		return viif_l1_set_preset_white_balance_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_RAW_COLOR_NOISE_REDUCTION:
> > +		return viif_l1_set_raw_color_noise_reduction_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_HDRS:
> > +		return viif_l1_set_hdrs_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_BLACK_LEVEL_CORRECTION:
> > +		return viif_l1_set_black_level_correction_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_LSC:
> > +		return viif_l1_set_lsc_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_MAIN_PROCESS:
> > +		return viif_l1_set_main_process_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_AWB:
> > +		return viif_l1_set_awb_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_LOCK_AWB_GAIN:
> > +		return 0;
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_HDRC:
> > +		return viif_l1_set_hdrc_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_HDRC_LTM:
> > +		return viif_l1_set_hdrc_ltm_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_GAMMA:
> > +		return viif_l1_set_gamma_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_IMG_QUALITY_ADJUSTMENT:
> > +		return viif_l1_set_img_quality_adjustment_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_AVG_LUM_GENERATION:
> > +		return viif_l1_set_avg_lum_generation_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L2_SET_UNDIST:
> > +		return viif_l2_set_undist_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L2_SET_ROI:
> > +		return viif_l2_set_roi_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_ISP_L2_SET_GAMMA:
> > +		return viif_l2_set_gamma_try(viif_dev, ctrl->p_new.p);
> > +	case V4L2_CID_VISCONTI_VIIF_GET_LAST_CAPTURE_STATUS:
> > +		return 0;
> > +	default:
> > +		pr_info("unknown_ctrl:t: id=%08X val=%d", ctrl->id, ctrl->val);
> > +		break;
> > +	}
> > +	return -EINVAL;
> > +}
> > +
> > +static int visconti_viif_isp_set_ctrl(struct v4l2_ctrl *ctrl)
> > +{
> > +	struct viif_device *viif_dev = ctrl->priv;
> > +	int ret;
> > +
> > +	pr_info("isp_set_ctrl: %s", ctrl->name);
> 
> Don't use pr_info for what is just a debug message! Either drop it, or
> replace it with dev_dbg.

In drivers, almost all occurences of pr_*() should be replaced by
dev_*(). It's very rare that pr_*() would be the right API.

In this specific case, I'd just drop it.

> > +	if (pm_runtime_status_suspended(viif_dev->dev)) {
> > +		pr_info("warning: visconti viif HW is not powered");
> 
> And here pr_info is used for a warning, so shouldn't this be dev_warn?

I don't think there's a need to warn about this, it's a normal
situation.

The right runtime PM API here is pm_runtime_get_if_in_use() by the way,
not pm_runtime_status_suspended(). Don't forget to call pm_runtime_put()
at the end of the function.

> I see pr_info being used in a lot of places where it doesn't belong and
> would just spam the kernel log.
>
> Something to go through for v8.
Hans Verkuil Aug. 21, 2023, 12:58 p.m. UTC | #5
Hi Yuji,

On 14/07/2023 03:50, Yuji Ishikawa wrote:
> This series is the Video Input Interface driver
> for Toshiba's ARM SoC, Visconti[0].
> This provides DT binding documentation,
> device driver, documentation and MAINTAINER files.
> 
> A visconti VIIF driver instance exposes
> 1 media control device file and 3 video device files
> for a VIIF hardware.
> Detailed HW/SW are described in documentation directory.
> The VIIF hardware has CSI2 receiver,
> image signal processor and DMAC inside.
> The subdevice for image signal processor provides
> vendor specific V4L2 controls.
> 
> The device driver depends on two other drivers under development;
> clock framework driver and IOMMU driver.
> Corresponding features will be added later.

Trying to compile this series on top of our latest staging tree fails
due to v4l2-async changes that have been merged. So for v8 please
rebase to the staging tree.

I also got a few kerneldoc warnings:

drivers/media/platform/toshiba/visconti/viif.h:217: warning: Function parameter or member 'ops_lock' not described in 'isp_subdev'
drivers/media/platform/toshiba/visconti/viif.h:233: warning: Function parameter or member 'ops_lock' not described in 'csi2rx_subdev'
drivers/media/platform/toshiba/visconti/viif.h:254: warning: Function parameter or member 'post_enable_flag' not described in 'viif_l2_roi_path_info'

Regards,

	Hans

> 
> Best regards,
> Yuji
> 
> Changelog v2:
> - Resend v1 because a patch exceeds size limit.
> 
> Changelog v3:
> - Add documentation to describe SW and HW
> - Adapted to media control framework
> - Introduced ISP subdevice, capture device
> - Remove private IOCTLs and add vendor specific V4L2 controls
> - Change function name avoiding camelcase and uppercase letters
> 
> Changelog v4:
> - Split patches because a patch exceeds size limit
> - fix dt-bindings document
> - stop specifying ID numbers for driver instance explicitly at device tree
> - use pm_runtime to trigger initialization of HW
>   along with open/close of device files.
> - add a entry for a header file at MAINTAINERS file
> 
> Changelog v5:
> - Fix coding style problem in viif.c (patch 2/6)
> 
> Changelog v6:
> - add register definition of BUS-IF and MPU in dt-bindings
> - add CSI2RX subdevice (separeted from ISP subdevice)
> - change directory layout (moved to media/platform/toshiba/visconti)
> - change source file layout (removed hwd_xxxx.c)
> - pointer to userland memory is removed from uAPI parameters
> - change register access (from struct style to macro style)
> - remove unused macros
> 
> Changelog v7:
> - remove redundant "bindings" from header and description text
> - fix multiline text of "description"
> - change "compatible" to "visconti5-viif"
> - explicitly define allowed properties for port::endpoint
> - remove unused variables
> - update kerneldoc comments
> - update references to headers
> 
> Yuji Ishikawa (5):
>   dt-bindings: media: platform: visconti: Add Toshiba Visconti Video
>     Input Interface
>   media: platform: visconti: Add Toshiba Visconti Video Input Interface
>     driver
>   media: add V4L2 vendor specific control handlers
>   documentation: media: add documentation for Toshiba Visconti Video
>     Input Interface driver
>   MAINTAINERS: Add entries for Toshiba Visconti Video Input Interface
> 
>  .../bindings/media/toshiba,visconti-viif.yaml |  108 +
>  .../driver-api/media/drivers/index.rst        |    1 +
>  .../media/drivers/visconti-viif.rst           |  462 +++
>  MAINTAINERS                                   |    4 +
>  drivers/media/platform/Kconfig                |    1 +
>  drivers/media/platform/Makefile               |    1 +
>  drivers/media/platform/toshiba/Kconfig        |    6 +
>  drivers/media/platform/toshiba/Makefile       |    2 +
>  .../media/platform/toshiba/visconti/Kconfig   |   18 +
>  .../media/platform/toshiba/visconti/Makefile  |    8 +
>  .../media/platform/toshiba/visconti/viif.c    |  681 ++++
>  .../media/platform/toshiba/visconti/viif.h    |  375 ++
>  .../platform/toshiba/visconti/viif_capture.c  | 1485 +++++++
>  .../platform/toshiba/visconti/viif_capture.h  |   22 +
>  .../platform/toshiba/visconti/viif_common.c   |  199 +
>  .../platform/toshiba/visconti/viif_common.h   |   38 +
>  .../platform/toshiba/visconti/viif_controls.c | 3407 +++++++++++++++++
>  .../platform/toshiba/visconti/viif_controls.h |   18 +
>  .../platform/toshiba/visconti/viif_csi2rx.c   |  684 ++++
>  .../platform/toshiba/visconti/viif_csi2rx.h   |   24 +
>  .../toshiba/visconti/viif_csi2rx_regs.h       |  102 +
>  .../platform/toshiba/visconti/viif_isp.c      | 1258 ++++++
>  .../platform/toshiba/visconti/viif_isp.h      |   24 +
>  .../platform/toshiba/visconti/viif_regs.h     |  716 ++++
>  include/uapi/linux/v4l2-controls.h            |    6 +
>  include/uapi/linux/visconti_viif.h            | 1800 +++++++++
>  26 files changed, 11450 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/toshiba,visconti-viif.yaml
>  create mode 100644 Documentation/driver-api/media/drivers/visconti-viif.rst
>  create mode 100644 drivers/media/platform/toshiba/Kconfig
>  create mode 100644 drivers/media/platform/toshiba/Makefile
>  create mode 100644 drivers/media/platform/toshiba/visconti/Kconfig
>  create mode 100644 drivers/media/platform/toshiba/visconti/Makefile
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif.c
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif.h
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_capture.c
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_capture.h
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_common.c
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_common.h
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_controls.c
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_controls.h
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_csi2rx.c
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_csi2rx.h
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_csi2rx_regs.h
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_isp.c
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_isp.h
>  create mode 100644 drivers/media/platform/toshiba/visconti/viif_regs.h
>  create mode 100644 include/uapi/linux/visconti_viif.h
>
Laurent Pinchart Aug. 21, 2023, 1:19 p.m. UTC | #6
(CC'ing Christoph, Marek and Robin)

On Tue, Jul 25, 2023 at 06:10:03AM +0000, yuji2.ishikawa@toshiba.co.jp wrote:
> On Friday, July 14, 2023 5:00 PM, Krzysztof Kozlowski wrote:
> > On 14/07/2023 03:50, Yuji Ishikawa wrote:
> > > Add support to Video Input Interface on Toshiba Visconti ARM SoCs.
> > > The interface device includes CSI2 Receiver, frame grabber, video DMAC
> > > and image signal processor.
> > >
> > > A driver instance provides three /dev/videoX device files; one for RGB
> > > image capture, another one for optional RGB capture with different
> > > parameters and the last one for RAW capture.
> > 
> > ...

[snip]

> > > +static int visconti_viif_probe(struct platform_device *pdev) {
> > > +	struct device *dev = &pdev->dev;
> > > +	struct viif_device *viif_dev;
> > > +	dma_addr_t tables_dma;
> > > +	int ret, i, num_sd;
> > > +
> > > +	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(36));
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	viif_dev = devm_kzalloc(dev, sizeof(*viif_dev), GFP_KERNEL);
> > > +	if (!viif_dev)
> > > +		return -ENOMEM;
> > > +
> > > +	platform_set_drvdata(pdev, viif_dev);
> > > +	viif_dev->dev = dev;
> > > +
> > > +	spin_lock_init(&viif_dev->regbuf_lock);
> > > +	mutex_init(&viif_dev->pow_lock);
> > > +	mutex_init(&viif_dev->stream_lock);
> > > +
> > > +	viif_dev->capture_reg = devm_platform_ioremap_resource(pdev, 0);
> > > +	if (IS_ERR(viif_dev->capture_reg))
> > > +		return PTR_ERR(viif_dev->capture_reg);
> > > +
> > > +	viif_dev->csi2host_reg = devm_platform_ioremap_resource(pdev, 1);
> > > +	if (IS_ERR(viif_dev->csi2host_reg))
> > > +		return PTR_ERR(viif_dev->csi2host_reg);
> > > +
> > > +	viif_dev->hwaif_reg = devm_platform_ioremap_resource(pdev, 2);
> > > +	if (IS_ERR(viif_dev->hwaif_reg))
> > > +		return PTR_ERR(viif_dev->hwaif_reg);
> > > +
> > > +	viif_dev->mpu_reg = devm_platform_ioremap_resource(pdev, 3);
> > > +	if (IS_ERR(viif_dev->mpu_reg))
> > > +		return PTR_ERR(viif_dev->mpu_reg);
> > > +
> > > +	viif_dev->run_flag_main = false;
> > > +
> > > +	for (i = 0; i < NUM_IRQS; i++) {
> > > +		ret = platform_get_irq(pdev, i);
> > > +		if (ret < 0) {
> > > +			dev_err(dev, "failed to acquire irq resource\n");
> > > +			return ret;
> > 
> > return dev_err_probe()
> 
> I'll use dev_err_probe().
> Same for other suggestions.
> 
> > > +		}
> > > +		viif_dev->irq[i] = ret;
> > > +		ret = devm_request_irq(dev, viif_dev->irq[i], visconti_viif_irq, 0, IRQ_ID_STR,
> > > +				       viif_dev);
> > > +		if (ret) {
> > > +			dev_err(dev, "irq request failed\n");
> > 
> > return dev_err_probe()
> 
> I'll use dev_err_probe().
> 
> > > +			return ret;
> > > +		}
> > > +	}
> > > +
> > > +	viif_dev->tables =
> > > +		dma_alloc_wc(dev, sizeof(struct viif_table_area), &tables_dma, GFP_KERNEL);
> > > +	if (!viif_dev->tables) {
> > > +		dev_err(dev, "dma_alloc_wc failed\n");
> > 
> > Are you sure DMA memory allocation errors shall be printed?
> 
> Printing this error is useless for users in general?
> If so, I'll drop this debug output.

Failures to allocate memory in the kernel generally result in warning
messages being printed by the allocation function, so there's no need to
do so manually in drivers. This being said, I check dma_alloc_wc()
(which is a wrapper around dma_alloc_attrs()), and unless I'm missing
something, it can return NULL without printing any error. I don't know
if this is an oversight in some code paths taken by dma_alloc_attrs() or
if it's on purpose. Maybe Christoph, Marek or Roben will known.

> > > +		return -ENOMEM;
> > > +	}
> > > +	viif_dev->tables_dma = (struct viif_table_area *)tables_dma;
> > > +
> > > +	/* power control */
> > 
> > Drop the comment, it is useless.
> 
> I'll drop the comment
> 
> > > +	pm_runtime_enable(dev);
> > > +
> > > +	/* build media_dev */
> > > +	viif_dev->media_dev.hw_revision = 0;
> > > +	strscpy(viif_dev->media_dev.model, VIIF_DRIVER_NAME, sizeof(viif_dev->media_dev.model));
> > > +	viif_dev->media_dev.dev = dev;
> > > +	/* TODO: platform:visconti-viif-0,1,2,3 for each VIIF driver instance */
> > > +	snprintf(viif_dev->media_dev.bus_info, sizeof(viif_dev->media_dev.bus_info), "%s-0",
> > > +		 VIIF_BUS_INFO_BASE);
> > > +	media_device_init(&viif_dev->media_dev);
> > > +
> > > +	/* build v4l2_dev */
> > > +	viif_dev->v4l2_dev.mdev = &viif_dev->media_dev;
> > > +	ret = v4l2_device_register(dev, &viif_dev->v4l2_dev);
> > > +	if (ret)
> > > +		goto error_dma_free;
> > > +
> > > +	ret = media_device_register(&viif_dev->media_dev);
> > > +	if (ret) {
> > > +		dev_err(dev, "Failed to register media device: %d\n", ret);
> > > +		goto error_v4l2_unregister;
> > 
> > dev_err_probe
> 
> I'll use dev_err_probe().
> 
> > > +	}
> > > +
> > > +	ret = visconti_viif_csi2rx_register(viif_dev);
> > > +	if (ret) {
> > > +		dev_err(dev, "failed to register csi2rx sub node: %d\n", ret);
> > 
> > dev_err_probe
> 
> I'll use dev_err_probe().
> 
> > > +		goto error_media_unregister;
> > > +	}
> > > +
> > > +	ret = visconti_viif_isp_register(viif_dev);
> > > +	if (ret) {
> > > +		dev_err(dev, "failed to register isp sub node: %d\n", ret);
> > 
> > dev_err_probe
> 
> I'll use dev_err_probe().
> 
> > > +		goto error_media_unregister;
> > > +	}
> > > +	ret = visconti_viif_capture_register(viif_dev);
> > > +	if (ret) {
> > > +		dev_err(dev, "failed to register capture node: %d\n", ret);
> > 
> > dev_err_probe
> 
> I'll use dev_err_probe().
> 
> > > +		goto error_media_unregister;
> > > +	}
> > > +
> > > +	/* handle subdevices in device tree */
> > > +	num_sd = visconti_viif_parse_dt(viif_dev);
> > > +	if (ret < 0) {
> > > +		ret = num_sd;
> > 
> > ret = dev_err_probe
> 
> I'll use dev_err_probe().
> 
> > > +		goto error_media_unregister;
> > > +	}
> > > +
> > > +	viif_dev->notifier.v4l2_dev = &viif_dev->v4l2_dev;
> > > +	v4l2_async_nf_init(&viif_dev->notifier);
> > > +	for (i = 0; i < num_sd; i++)
> > > +		__v4l2_async_nf_add_subdev(&viif_dev->notifier, viif_dev->asds[i]);
> > > +	viif_dev->notifier.ops = &viif_notify_ops;
> > > +	ret = v4l2_async_nf_register(&viif_dev->v4l2_dev, &viif_dev->notifier);
> > > +	if (ret)
> > > +		goto error_media_unregister;
> > > +
> > > +	viif_dev->wq = create_workqueue("visconti-viif");
> > > +	if (!viif_dev->wq)
> > > +		return -ENOMEM;
> > 
> > No error cleanup?
> 
> There should be. I'll add cleanup operations.
> 
> > > +	INIT_WORK(&viif_dev->work, visconti_viif_wthread_l1info);
> > > +
> > > +	return 0;
> > > +
> > > +error_media_unregister:
> > > +	media_device_unregister(&viif_dev->media_dev);
> > > +error_v4l2_unregister:
> > > +	v4l2_device_unregister(&viif_dev->v4l2_dev);
> > > +error_dma_free:
> > > +	pm_runtime_disable(dev);
> > > +	dma_free_wc(&pdev->dev, sizeof(struct viif_table_area), viif_dev->tables,
> > > +		    (dma_addr_t)viif_dev->tables_dma);
> > > +	return ret;
> > > +}

[snip]
Robin Murphy Aug. 21, 2023, 1:35 p.m. UTC | #7
On 2023-08-21 14:19, Laurent Pinchart wrote:
[...]
>>>> +	viif_dev->tables =
>>>> +		dma_alloc_wc(dev, sizeof(struct viif_table_area), &tables_dma, GFP_KERNEL);
>>>> +	if (!viif_dev->tables) {
>>>> +		dev_err(dev, "dma_alloc_wc failed\n");
>>>
>>> Are you sure DMA memory allocation errors shall be printed?
>>
>> Printing this error is useless for users in general?
>> If so, I'll drop this debug output.
> 
> Failures to allocate memory in the kernel generally result in warning
> messages being printed by the allocation function, so there's no need to
> do so manually in drivers. This being said, I check dma_alloc_wc()
> (which is a wrapper around dma_alloc_attrs()), and unless I'm missing
> something, it can return NULL without printing any error. I don't know
> if this is an oversight in some code paths taken by dma_alloc_attrs() or
> if it's on purpose. Maybe Christoph, Marek or Roben will known.

Yeah, there might be a few edge cases, but in most cases 
dma_alloc_attrs() will end up falling back to the page allocator as a 
last resort if all the more preferred allocation options fail, and thus 
complete failure should eventually cause that to scream unless 
DMA_ATTR_NO_WARN was specified.

Thanks,
Robin.
Yuji Ishikawa Aug. 30, 2023, 12:44 a.m. UTC | #8
Hello Hans,

> -----Original Message-----
> From: Hans Verkuil <hverkuil@xs4all.nl>
> Sent: Monday, August 21, 2023 9:59 PM
> To: ishikawa yuji(石川 悠司 ○RDC□AITC○EA開)
> <yuji2.ishikawa@toshiba.co.jp>; Sakari Ailus <sakari.ailus@iki.fi>; Laurent
> Pinchart <laurent.pinchart@ideasonboard.com>; Mauro Carvalho Chehab
> <mchehab@kernel.org>; Rob Herring <robh+dt@kernel.org>; Krzysztof
> Kozlowski <krzysztof.kozlowski+dt@linaro.org>; Conor Dooley
> <conor+dt@kernel.org>; iwamatsu nobuhiro(岩松 信洋 ○DITC□DIT○
> OST) <nobuhiro1.iwamatsu@toshiba.co.jp>; Mark Brown
> <broonie@kernel.org>
> Cc: linux-media@vger.kernel.org; devicetree@vger.kernel.org;
> linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v7 0/5] Add Toshiba Visconti Video Input Interface driver
> 
> Hi Yuji,
> 
> On 14/07/2023 03:50, Yuji Ishikawa wrote:
> > This series is the Video Input Interface driver for Toshiba's ARM SoC,
> > Visconti[0].
> > This provides DT binding documentation, device driver, documentation
> > and MAINTAINER files.
> >
> > A visconti VIIF driver instance exposes
> > 1 media control device file and 3 video device files for a VIIF
> > hardware.
> > Detailed HW/SW are described in documentation directory.
> > The VIIF hardware has CSI2 receiver,
> > image signal processor and DMAC inside.
> > The subdevice for image signal processor provides vendor specific V4L2
> > controls.
> >
> > The device driver depends on two other drivers under development;
> > clock framework driver and IOMMU driver.
> > Corresponding features will be added later.
> 
> Trying to compile this series on top of our latest staging tree fails due to
> v4l2-async changes that have been merged. So for v8 please rebase to the
> staging tree.

All right. The v8 patchset will be rebased to media_stage.git .

> I also got a few kerneldoc warnings:
> 
> drivers/media/platform/toshiba/visconti/viif.h:217: warning: Function
> parameter or member 'ops_lock' not described in 'isp_subdev'
> drivers/media/platform/toshiba/visconti/viif.h:233: warning: Function
> parameter or member 'ops_lock' not described in 'csi2rx_subdev'
> drivers/media/platform/toshiba/visconti/viif.h:254: warning: Function
> parameter or member 'post_enable_flag' not described in 'viif_l2_roi_path_info'

I'll check for kerneldoc warnings and fix them.

Regards,
Yuji

> Regards,
> 
> 	Hans
> 
> >
> > Best regards,
> > Yuji
> >
> > Changelog v2:
> > - Resend v1 because a patch exceeds size limit.
> >
> > Changelog v3:
> > - Add documentation to describe SW and HW
> > - Adapted to media control framework
> > - Introduced ISP subdevice, capture device
> > - Remove private IOCTLs and add vendor specific V4L2 controls
> > - Change function name avoiding camelcase and uppercase letters
> >
> > Changelog v4:
> > - Split patches because a patch exceeds size limit
> > - fix dt-bindings document
> > - stop specifying ID numbers for driver instance explicitly at device
> > tree
> > - use pm_runtime to trigger initialization of HW
> >   along with open/close of device files.
> > - add a entry for a header file at MAINTAINERS file
> >
> > Changelog v5:
> > - Fix coding style problem in viif.c (patch 2/6)
> >
> > Changelog v6:
> > - add register definition of BUS-IF and MPU in dt-bindings
> > - add CSI2RX subdevice (separeted from ISP subdevice)
> > - change directory layout (moved to media/platform/toshiba/visconti)
> > - change source file layout (removed hwd_xxxx.c)
> > - pointer to userland memory is removed from uAPI parameters
> > - change register access (from struct style to macro style)
> > - remove unused macros
> >
> > Changelog v7:
> > - remove redundant "bindings" from header and description text
> > - fix multiline text of "description"
> > - change "compatible" to "visconti5-viif"
> > - explicitly define allowed properties for port::endpoint
> > - remove unused variables
> > - update kerneldoc comments
> > - update references to headers
> >
> > Yuji Ishikawa (5):
> >   dt-bindings: media: platform: visconti: Add Toshiba Visconti Video
> >     Input Interface
> >   media: platform: visconti: Add Toshiba Visconti Video Input Interface
> >     driver
> >   media: add V4L2 vendor specific control handlers
> >   documentation: media: add documentation for Toshiba Visconti Video
> >     Input Interface driver
> >   MAINTAINERS: Add entries for Toshiba Visconti Video Input Interface
> >
> >  .../bindings/media/toshiba,visconti-viif.yaml |  108 +
> >  .../driver-api/media/drivers/index.rst        |    1 +
> >  .../media/drivers/visconti-viif.rst           |  462 +++
> >  MAINTAINERS                                   |    4 +
> >  drivers/media/platform/Kconfig                |    1 +
> >  drivers/media/platform/Makefile               |    1 +
> >  drivers/media/platform/toshiba/Kconfig        |    6 +
> >  drivers/media/platform/toshiba/Makefile       |    2 +
> >  .../media/platform/toshiba/visconti/Kconfig   |   18 +
> >  .../media/platform/toshiba/visconti/Makefile  |    8 +
> >  .../media/platform/toshiba/visconti/viif.c    |  681 ++++
> >  .../media/platform/toshiba/visconti/viif.h    |  375 ++
> >  .../platform/toshiba/visconti/viif_capture.c  | 1485 +++++++
> >  .../platform/toshiba/visconti/viif_capture.h  |   22 +
> >  .../platform/toshiba/visconti/viif_common.c   |  199 +
> >  .../platform/toshiba/visconti/viif_common.h   |   38 +
> >  .../platform/toshiba/visconti/viif_controls.c | 3407
> +++++++++++++++++
> >  .../platform/toshiba/visconti/viif_controls.h |   18 +
> >  .../platform/toshiba/visconti/viif_csi2rx.c   |  684 ++++
> >  .../platform/toshiba/visconti/viif_csi2rx.h   |   24 +
> >  .../toshiba/visconti/viif_csi2rx_regs.h       |  102 +
> >  .../platform/toshiba/visconti/viif_isp.c      | 1258 ++++++
> >  .../platform/toshiba/visconti/viif_isp.h      |   24 +
> >  .../platform/toshiba/visconti/viif_regs.h     |  716 ++++
> >  include/uapi/linux/v4l2-controls.h            |    6 +
> >  include/uapi/linux/visconti_viif.h            | 1800 +++++++++
> >  26 files changed, 11450 insertions(+)  create mode 100644
> > Documentation/devicetree/bindings/media/toshiba,visconti-viif.yaml
> >  create mode 100644
> > Documentation/driver-api/media/drivers/visconti-viif.rst
> >  create mode 100644 drivers/media/platform/toshiba/Kconfig
> >  create mode 100644 drivers/media/platform/toshiba/Makefile
> >  create mode 100644 drivers/media/platform/toshiba/visconti/Kconfig
> >  create mode 100644 drivers/media/platform/toshiba/visconti/Makefile
> >  create mode 100644 drivers/media/platform/toshiba/visconti/viif.c
> >  create mode 100644 drivers/media/platform/toshiba/visconti/viif.h
> >  create mode 100644
> > drivers/media/platform/toshiba/visconti/viif_capture.c
> >  create mode 100644
> > drivers/media/platform/toshiba/visconti/viif_capture.h
> >  create mode 100644
> > drivers/media/platform/toshiba/visconti/viif_common.c
> >  create mode 100644
> > drivers/media/platform/toshiba/visconti/viif_common.h
> >  create mode 100644
> > drivers/media/platform/toshiba/visconti/viif_controls.c
> >  create mode 100644
> > drivers/media/platform/toshiba/visconti/viif_controls.h
> >  create mode 100644
> > drivers/media/platform/toshiba/visconti/viif_csi2rx.c
> >  create mode 100644
> > drivers/media/platform/toshiba/visconti/viif_csi2rx.h
> >  create mode 100644
> > drivers/media/platform/toshiba/visconti/viif_csi2rx_regs.h
> >  create mode 100644 drivers/media/platform/toshiba/visconti/viif_isp.c
> >  create mode 100644 drivers/media/platform/toshiba/visconti/viif_isp.h
> >  create mode 100644
> > drivers/media/platform/toshiba/visconti/viif_regs.h
> >  create mode 100644 include/uapi/linux/visconti_viif.h
> >
Yuji Ishikawa Aug. 30, 2023, 12:46 a.m. UTC | #9
Hello Laurent, Hans,

> -----Original Message-----
> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Sent: Monday, August 21, 2023 9:34 PM
> To: Hans Verkuil <hverkuil@xs4all.nl>
> Cc: ishikawa yuji(石川 悠司 ○RDC□AITC○EA開)
> <yuji2.ishikawa@toshiba.co.jp>; Sakari Ailus <sakari.ailus@iki.fi>; Mauro
> Carvalho Chehab <mchehab@kernel.org>; Rob Herring <robh+dt@kernel.org>;
> Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>; Conor Dooley
> <conor+dt@kernel.org>; iwamatsu nobuhiro(岩松 信洋 ○DITC□DIT○
> OST) <nobuhiro1.iwamatsu@toshiba.co.jp>; Mark Brown
> <broonie@kernel.org>; linux-media@vger.kernel.org;
> devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v7 3/5] media: add V4L2 vendor specific control handlers
> 
> On Mon, Aug 21, 2023 at 02:28:11PM +0200, Hans Verkuil wrote:
> > On 14/07/2023 03:50, Yuji Ishikawa wrote:
> > > Add support to Image Signal Processors of Visconti's Video Input Interface.
> > > This patch adds vendor specific compound controls to configure the
> > > image signal processor.
> > >
> > > Signed-off-by: Yuji Ishikawa <yuji2.ishikawa@toshiba.co.jp>
> > > ---
> > > Changelog v2:
> > > - Resend v1 because a patch exceeds size limit.
> > >
> > > Changelog v3:
> > > - Adapted to media control framework
> > > - Introduced ISP subdevice, capture device
> > > - Remove private IOCTLs and add vendor specific V4L2 controls
> > > - Change function name avoiding camelcase and uppercase letters
> > >
> > > Changelog v4:
> > > - Split patches because the v3 patch exceeds size limit
> > > - Stop using ID number to identify driver instance:
> > >   - Use dynamically allocated structure to hold HW specific context,
> > >     instead of static one.
> > >   - Call HW layer functions with the context structure instead of ID
> > > number
> > >
> > > Changelog v5:
> > > - no change
> > >
> > > Changelog v6:
> > > - remove unused macros
> > > - removed hwd_ and HWD_ prefix
> > > - update source code documentation
> > > - Suggestion from Hans Verkuil
> > >   - pointer to userland memory is removed from uAPI arguments
> > >     - style of structure is now "nested" instead of "chained by pointer";
> > >   - use div64_u64 for 64bit division
> > >   - vendor specific controls support TRY_EXT_CTRLS
> > >   - add READ_ONLY flag to GET_CALIBRATION_STATUS control and
> similar ones
> > >   - human friendry control names for vendor specific controls
> > >   - add initial value to each vendor specific control
> > >   - GET_LAST_CAPTURE_STATUS control is updated asyncnously from
> workqueue
> > >   - remove EXECUTE_ON_WRITE flag of vendor specific control
> > >   - uAPI: return value of GET_CALIBRATION_STATUS follows common
> rules of error codes
> > >   - applied v4l2-compliance
> > > - Suggestion from Sakari Ailus
> > >   - use div64_u64 for 64bit division
> > >   - update copyright's year
> > >   - remove redandunt cast
> > >   - use bool instead of HWD_VIIF_ENABLE/DISABLE
> > >   - simplify comparison to 0
> > >   - simplify statements with trigram operator
> > >   - remove redundant local variables
> > >   - use general integer types instead of u32/s32
> > > - Suggestion from Laurent Pinchart
> > >   - moved VIIF driver to driver/platform/toshiba/visconti
> > >   - change register access: struct-style to macro-style
> > >   - remove unused type definitions
> > >   - define enums instead of successive macro constants
> > >   - remove redundant parenthesis of macro constant
> > >   - embed struct hwd_res into struct viif_device
> > >   - use xxx_dma instead of xxx_paddr for variable names of IOVA
> > >   - literal value: just 0 instead of 0x0
> > >   - use literal 1 or 0 instead of HWD_VIIF_ENABLE, DISABLE for register
> access
> > >   - use true or false instead of HWD_VIIF_ENABLE, DISABLE for function
> calls
> > >   - uAPI: return value of GET_CALIBRATION_STATUS follows common
> > > rules of error codes
> > >
> > > Changelog v7:
> > > - remove unused variables
> > > - split long statements which have multiple logical-OR and trigram
> > > operators
> > >
> > >  .../media/platform/toshiba/visconti/Makefile  |    2 +-
> > >  .../media/platform/toshiba/visconti/viif.c    |   10 +-
> > >  .../platform/toshiba/visconti/viif_controls.c | 3407
> +++++++++++++++++
> > >  .../platform/toshiba/visconti/viif_controls.h |   18 +
> > >  .../platform/toshiba/visconti/viif_isp.c      |   15 +-
> > >  5 files changed, 3435 insertions(+), 17 deletions(-)  create mode
> > > 100644 drivers/media/platform/toshiba/visconti/viif_controls.c
> > >  create mode 100644
> > > drivers/media/platform/toshiba/visconti/viif_controls.h
> > >
> > > diff --git a/drivers/media/platform/toshiba/visconti/Makefile
> > > b/drivers/media/platform/toshiba/visconti/Makefile
> > > index 5f2f9199c..a28e6fa84 100644
> > > --- a/drivers/media/platform/toshiba/visconti/Makefile
> > > +++ b/drivers/media/platform/toshiba/visconti/Makefile
> > > @@ -3,6 +3,6 @@
> > >  # Makefile for the Visconti video input device driver  #
> > >
> > > -visconti-viif-objs = viif.o viif_capture.o viif_isp.o viif_csi2rx.o
> > > viif_common.o
> > > +visconti-viif-objs = viif.o viif_capture.o viif_controls.o
> > > +viif_isp.o viif_csi2rx.o viif_common.o
> > >
> > >  obj-$(CONFIG_VIDEO_VISCONTI_VIIF) += visconti-viif.o diff --git
> > > a/drivers/media/platform/toshiba/visconti/viif.c
> > > b/drivers/media/platform/toshiba/visconti/viif.c
> > > index c07dc2626..1b3d61abf 100644
> > > --- a/drivers/media/platform/toshiba/visconti/viif.c
> > > +++ b/drivers/media/platform/toshiba/visconti/viif.c
> > > @@ -18,6 +18,7 @@
> > >
> > >  #include "viif.h"
> > >  #include "viif_capture.h"
> > > +#include "viif_controls.h"
> > >  #include "viif_csi2rx.h"
> > >  #include "viif_common.h"
> > >  #include "viif_isp.h"
> > > @@ -178,12 +179,9 @@ static struct viif_subdev
> > > *to_viif_subdev(struct v4l2_async_subdev *asd)
> > >  /* before a userland capture application is trigered by
> > > vb2_buffer_done() */  static void
> > > visconti_viif_wthread_l1info(struct work_struct *work)  {
> > > -	/* called function is implemented by the next patch */
> > > -/*
> > > - *	struct viif_device *viif_dev = container_of(work, struct viif_device,
> work);
> > > - *
> > > - *	visconti_viif_save_l1_info(viif_dev);
> > > - */
> > > +	struct viif_device *viif_dev = container_of(work, struct
> > > +viif_device, work);
> > > +
> > > +	visconti_viif_save_l1_info(viif_dev);
> > >  }
> > >
> > >  static void viif_vsync_irq_handler_w_isp(struct viif_device
> > > *viif_dev) diff --git
> > > a/drivers/media/platform/toshiba/visconti/viif_controls.c
> > > b/drivers/media/platform/toshiba/visconti/viif_controls.c
> > > new file mode 100644
> > > index 000000000..3cf10e15c
> > > --- /dev/null
> > > +++ b/drivers/media/platform/toshiba/visconti/viif_controls.c
> > > @@ -0,0 +1,3407 @@
> >
> > <snip>
> >
> > > +static int visconti_viif_isp_try_ctrl(struct v4l2_ctrl *ctrl) {
> > > +	struct viif_device *viif_dev = ctrl->priv;
> > > +
> > > +	switch (ctrl->id) {
> > > +	case V4L2_CID_VISCONTI_VIIF_MAIN_SET_RAWPACK_MODE:
> > > +		return viif_main_set_rawpack_mode_try(viif_dev,
> ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_INPUT_MODE:
> > > +		return viif_l1_set_input_mode_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_RGB_TO_Y_COEF:
> > > +		return viif_l1_set_rgb_to_y_coef_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_AG_MODE:
> > > +		return viif_l1_set_ag_mode_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_AG:
> > > +		return 0; //no need to check
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_HDRE:
> > > +		return viif_l1_set_hdre_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_IMG_EXTRACTION:
> > > +		return viif_l1_set_img_extraction_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_DPC:
> > > +		return viif_l1_set_dpc_try(viif_dev, ctrl->p_new.p);
> > > +	case
> V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_PRESET_WHITE_BALANCE:
> > > +		return viif_l1_set_preset_white_balance_try(viif_dev,
> ctrl->p_new.p);
> > > +	case
> V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_RAW_COLOR_NOISE_REDUCTION:
> > > +		return viif_l1_set_raw_color_noise_reduction_try(viif_dev,
> ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_HDRS:
> > > +		return viif_l1_set_hdrs_try(viif_dev, ctrl->p_new.p);
> > > +	case
> V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_BLACK_LEVEL_CORRECTION:
> > > +		return viif_l1_set_black_level_correction_try(viif_dev,
> ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_LSC:
> > > +		return viif_l1_set_lsc_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_MAIN_PROCESS:
> > > +		return viif_l1_set_main_process_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_AWB:
> > > +		return viif_l1_set_awb_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_LOCK_AWB_GAIN:
> > > +		return 0;
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_HDRC:
> > > +		return viif_l1_set_hdrc_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_HDRC_LTM:
> > > +		return viif_l1_set_hdrc_ltm_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_GAMMA:
> > > +		return viif_l1_set_gamma_try(viif_dev, ctrl->p_new.p);
> > > +	case
> V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_IMG_QUALITY_ADJUSTMENT:
> > > +		return viif_l1_set_img_quality_adjustment_try(viif_dev,
> ctrl->p_new.p);
> > > +	case
> V4L2_CID_VISCONTI_VIIF_ISP_L1_SET_AVG_LUM_GENERATION:
> > > +		return viif_l1_set_avg_lum_generation_try(viif_dev,
> ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L2_SET_UNDIST:
> > > +		return viif_l2_set_undist_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L2_SET_ROI:
> > > +		return viif_l2_set_roi_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_ISP_L2_SET_GAMMA:
> > > +		return viif_l2_set_gamma_try(viif_dev, ctrl->p_new.p);
> > > +	case V4L2_CID_VISCONTI_VIIF_GET_LAST_CAPTURE_STATUS:
> > > +		return 0;
> > > +	default:
> > > +		pr_info("unknown_ctrl:t: id=%08X val=%d", ctrl->id, ctrl->val);
> > > +		break;
> > > +	}
> > > +	return -EINVAL;
> > > +}
> > > +
> > > +static int visconti_viif_isp_set_ctrl(struct v4l2_ctrl *ctrl) {
> > > +	struct viif_device *viif_dev = ctrl->priv;
> > > +	int ret;
> > > +
> > > +	pr_info("isp_set_ctrl: %s", ctrl->name);
> >
> > Don't use pr_info for what is just a debug message! Either drop it, or
> > replace it with dev_dbg.
> 
> In drivers, almost all occurences of pr_*() should be replaced by dev_*(). It's very
> rare that pr_*() would be the right API.
> 
> In this specific case, I'd just drop it.
> 

I'll remove pr_*() calls.

> > > +	if (pm_runtime_status_suspended(viif_dev->dev)) {
> > > +		pr_info("warning: visconti viif HW is not powered");
> >
> > And here pr_info is used for a warning, so shouldn't this be dev_warn?
> 
> I don't think there's a need to warn about this, it's a normal situation.
> 
> The right runtime PM API here is pm_runtime_get_if_in_use() by the way, not
> pm_runtime_status_suspended(). Don't forget to call pm_runtime_put() at the
> end of the function.
> 

I'll remove this pr_info() call.
Also, I'll use pm_runtime_get_if_in_use() instead of pm_runtime_status_suspended().

> > I see pr_info being used in a lot of places where it doesn't belong
> > and would just spam the kernel log.
> >
> > Something to go through for v8.
> 
> --
> Regards,
> 
> Laurent Pinchart

Regards,
Yuji
Yuji Ishikawa Aug. 30, 2023, 12:47 a.m. UTC | #10
Hello Robin, Laurent,

> -----Original Message-----
> From: Robin Murphy <robin.murphy@arm.com>
> Sent: Monday, August 21, 2023 10:36 PM
> To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>; ishikawa yuji(石川
> 悠司 ○RDC□AITC○EA開) <yuji2.ishikawa@toshiba.co.jp>
> Cc: krzysztof.kozlowski@linaro.org; hverkuil@xs4all.nl; sakari.ailus@iki.fi;
> mchehab@kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org;
> conor+dt@kernel.org; iwamatsu nobuhiro(岩松 信洋 ○DITC□DIT○OS
> T) <nobuhiro1.iwamatsu@toshiba.co.jp>; broonie@kernel.org;
> linux-media@vger.kernel.org; devicetree@vger.kernel.org;
> linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; Christoph
> Hellwig <hch@lst.de>; Marek Szyprowski <m.szyprowski@samsung.com>
> Subject: Re: [PATCH v7 2/5] media: platform: visconti: Add Toshiba Visconti
> Video Input Interface driver
> 
> On 2023-08-21 14:19, Laurent Pinchart wrote:
> [...]
> >>>> +	viif_dev->tables =
> >>>> +		dma_alloc_wc(dev, sizeof(struct viif_table_area),
> &tables_dma, GFP_KERNEL);
> >>>> +	if (!viif_dev->tables) {
> >>>> +		dev_err(dev, "dma_alloc_wc failed\n");
> >>>
> >>> Are you sure DMA memory allocation errors shall be printed?
> >>
> >> Printing this error is useless for users in general?
> >> If so, I'll drop this debug output.
> >
> > Failures to allocate memory in the kernel generally result in warning
> > messages being printed by the allocation function, so there's no need
> > to do so manually in drivers. This being said, I check dma_alloc_wc()
> > (which is a wrapper around dma_alloc_attrs()), and unless I'm missing
> > something, it can return NULL without printing any error. I don't know
> > if this is an oversight in some code paths taken by dma_alloc_attrs()
> > or if it's on purpose. Maybe Christoph, Marek or Roben will known.
> 
> Yeah, there might be a few edge cases, but in most cases
> dma_alloc_attrs() will end up falling back to the page allocator as a last resort if
> all the more preferred allocation options fail, and thus complete failure should
> eventually cause that to scream unless DMA_ATTR_NO_WARN was specified.

I understand there's no need for printing this error message at driver code.
I'll remove dev_err().

> Thanks,
> Robin.

Regards,
Yuji