From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: jacopo mondi <jacopo@jmondi.org>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>,
magnus.damm@gmail.com, geert@glider.be, mchehab@kernel.org,
hverkuil@xs4all.nl, linux-renesas-soc@vger.kernel.org,
linux-media@vger.kernel.org, linux-sh@vger.kernel.org,
linux-kernel@vger.kernel.org, sakari.ailus@iki.fi
Subject: Re: [PATCH v1 03/10] v4l: platform: Add Renesas CEU driver
Date: Tue, 19 Dec 2017 15:07:41 +0200 [thread overview]
Message-ID: <1605194.apxP3rZ1bD@avalon> (raw)
In-Reply-To: <20171219115742.GB27115@w540>
Hi Jacopo,
(CC'ing Sakari)
On Tuesday, 19 December 2017 13:57:42 EET jacopo mondi wrote:
> On Mon, Dec 11, 2017 at 06:15:23PM +0200, Laurent Pinchart wrote:
> > Hi Jacopo,
> >
> > Thank you for the patch.
> >
> > [snip]
> >
> >> +static int ceu_sensor_bound(struct v4l2_async_notifier *notifier,
> >> + struct v4l2_subdev *v4l2_sd,
> >> + struct v4l2_async_subdev *asd)
> >> +{
> >> + struct v4l2_device *v4l2_dev = notifier->v4l2_dev;
> >> + struct ceu_device *ceudev = v4l2_to_ceu(v4l2_dev);
> >> + struct ceu_subdev *ceu_sd = to_ceu_subdev(asd);
> >> +
> >> + if (video_is_registered(&ceudev->vdev)) {
> >> + v4l2_err(&ceudev->v4l2_dev,
> >> + "Video device registered before this sub-device.\n");
> >> + return -EBUSY;
> >
> > Can this happen ?
> >
> >> + }
> >> +
> >> + /* Assign subdevices in the order they appear */
> >> + ceu_sd->v4l2_sd = v4l2_sd;
> >> + ceudev->num_sd++;
> >> +
> >> + return 0;
> >> +}
> >> +
> > > +static int ceu_sensor_complete(struct v4l2_async_notifier *notifier)
> > > +{
> > > + struct v4l2_device *v4l2_dev = notifier->v4l2_dev;
> > > + struct ceu_device *ceudev = v4l2_to_ceu(v4l2_dev);
> > > + struct video_device *vdev = &ceudev->vdev;
> > > + struct vb2_queue *q = &ceudev->vb2_vq;
> > > + struct v4l2_subdev *v4l2_sd;
> > > + int ret;
> > > +
> > > + /* Initialize vb2 queue */
> > > + q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
> > > + q->io_modes = VB2_MMAP | VB2_USERPTR;
> >
> > No dmabuf ?
> >
> > > + q->drv_priv = ceudev;
> > > + q->ops = &ceu_videobuf_ops;
> > > + q->mem_ops = &vb2_dma_contig_memops;
> > > + q->buf_struct_size = sizeof(struct ceu_buffer);
> > > + q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> > > + q->lock = &ceudev->mlock;
> > > + q->dev = ceudev->v4l2_dev.dev;
> >
> > [snip]
> >
> > > +static int ceu_probe(struct platform_device *pdev)
> > > +{
> > > + struct device *dev = &pdev->dev;
> > > + struct ceu_device *ceudev;
> > > + struct resource *res;
> > > + void __iomem *base;
> > > + unsigned int irq;
> > > + int num_sd;
> > > + int ret;
> > > +
> > > + ceudev = kzalloc(sizeof(*ceudev), GFP_KERNEL);
> >
> > The memory is freed in ceu_vdev_release() as expected, but that will only
> > work if the video device is registered. If the subdevs are never bound,
> > the ceudev memory will be leaked if you unbind the CEU device from its
> > driver. In my opinion this calls for registering the video device at
> > probe time (although Hans disagrees).
> >
> > > + if (!ceudev)
> > > + return -ENOMEM;
> > > +
> > > + platform_set_drvdata(pdev, ceudev);
> > > + dev_set_drvdata(dev, ceudev);
> >
> > You don't need the second line, platform_set_drvdata() is a wrapper around
> > dev_set_drvdata().
> >
> > > + ceudev->dev = dev;
> > > +
> > > + INIT_LIST_HEAD(&ceudev->capture);
> > > + spin_lock_init(&ceudev->lock);
> > > + mutex_init(&ceudev->mlock);
> > > +
> > > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > + if (IS_ERR(res))
> > > + return PTR_ERR(res);
> >
> > No need for error handling here, devm_ioremap_resource() will check the
> > res
> > pointer.
> >
> > > + base = devm_ioremap_resource(dev, res);
> >
> > You can assign ceudev->base directly and remove the base local variable.
> >
> > > + if (IS_ERR(base))
> > > + return PTR_ERR(base);
> > > + ceudev->base = base;
> > > +
> > > + ret = platform_get_irq(pdev, 0);
> > > + if (ret < 0) {
> > > + dev_err(dev, "failed to get irq: %d\n", ret);
> > > + return ret;
> > > + }
> > > + irq = ret;
> > > +
> > > + ret = devm_request_irq(dev, irq, ceu_irq,
> > > + 0, dev_name(dev), ceudev);
> > > + if (ret) {
> > > + dev_err(&pdev->dev, "Unable to register CEU interrupt.\n");
> > > + return ret;
> > > + }
> > > +
> > > + pm_suspend_ignore_children(dev, true);
> > > + pm_runtime_enable(dev);
> > > +
> > > + ret = v4l2_device_register(dev, &ceudev->v4l2_dev);
> > > + if (ret)
> > > + goto error_pm_disable;
> > > +
> > > + if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
> > > + num_sd = ceu_parse_dt(ceudev);
> > > + } else if (dev->platform_data) {
> > > + num_sd = ceu_parse_platform_data(ceudev, dev->platform_data);
> > > + } else {
> > > + dev_err(dev, "CEU platform data not set and no OF support\n");
> > > + ret = -EINVAL;
> > > + goto error_v4l2_unregister;
> > > + }
> > > +
> > > + if (num_sd < 0) {
> > > + ret = num_sd;
> > > + goto error_v4l2_unregister;
> > > + } else if (num_sd == 0)
> > > + return 0;
> >
> > You need braces around the second statement too.
>
> Ok, actually parse_dt() and parse_platform_data() behaves differently.
> The former returns error if no subdevices are connected to CEU, the
> latter returns 0. That's wrong.
>
> I wonder what's the correct behavior here. Other mainline drivers I
> looked into (pxa_camera and atmel-isc) behaves differently from each
> other, so I guess this is up to each platform to decide.
No, what it means is that we've failed to standardize it, not that it
shouldn't be standardized :-)
> Also, the CEU can accept one single input (and I made it clear
> in DT bindings documentation saying it accepts a single endpoint,
> while I'm parsing all the available ones in driver, I will fix this)
> but as it happens on Migo-R, there could be HW hacks to share the input
> lines between multiple subdevices. Should I accept it from dts as well?
>
> So:
> 1) Should we fail to probe if no subdevices are connected?
While the CEU itself would be fully functional without a subdev, in practice
it would be of no use. I would thus fail probing.
> 2) Should we accept more than 1 subdevice from dts as it happens right
> now for platform data?
We need to support multiple connected devices, as some of the boards require
that. What I'm not sure about is whether the multiplexer on the Migo-R board
should be modeled as a subdevice. We could in theory connect multiple sensors
to the CEU input signals without any multiplexer as long as all but one are in
reset with their outputs in a high impedance state. As that wouldn' require a
multiplexer we would need to support multiple endpoints in the CEU port. We
could then support Migo-R the same way, making the multiplexer transparent.
Sakari, what would you do here ?
--
Regards,
Laurent Pinchart
next prev parent reply other threads:[~2017-12-19 13:07 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-15 10:55 [PATCH v1 00/10] Renesas Capture Engine Unit (CEU) V4L2 driver Jacopo Mondi
2017-11-15 10:55 ` [PATCH v1 01/10] dt-bindings: media: Add Renesas CEU bindings Jacopo Mondi
2017-11-15 11:32 ` Kieran Bingham
2017-11-15 12:33 ` Sakari Ailus
2017-12-11 14:24 ` Laurent Pinchart
2017-11-15 13:07 ` Geert Uytterhoeven
2017-11-15 18:15 ` jacopo mondi
2017-11-15 18:39 ` Geert Uytterhoeven
2017-11-15 10:55 ` [PATCH v1 02/10] include: media: Add Renesas CEU driver interface Jacopo Mondi
2017-11-15 12:36 ` Sakari Ailus
2017-12-11 14:26 ` Laurent Pinchart
2017-12-11 14:32 ` Laurent Pinchart
2017-11-15 10:55 ` [PATCH v1 03/10] v4l: platform: Add Renesas CEU driver Jacopo Mondi
2017-11-15 12:45 ` Sakari Ailus
2017-11-15 14:25 ` jacopo mondi
2017-11-17 0:36 ` Sakari Ailus
2017-11-17 9:33 ` jacopo mondi
2017-11-25 15:56 ` Sakari Ailus
2017-11-25 18:17 ` jacopo mondi
2017-12-11 15:04 ` Laurent Pinchart
2017-12-11 16:15 ` Laurent Pinchart
2017-12-18 12:25 ` jacopo mondi
2017-12-18 15:28 ` Laurent Pinchart
2017-12-21 16:27 ` jacopo mondi
2017-12-22 12:03 ` Laurent Pinchart
2017-12-22 14:40 ` jacopo mondi
2017-12-23 11:39 ` Laurent Pinchart
2017-12-19 11:57 ` jacopo mondi
2017-12-19 13:07 ` Laurent Pinchart [this message]
2017-12-19 13:28 ` Sakari Ailus
2017-12-19 13:52 ` Laurent Pinchart
2017-12-13 12:03 ` Hans Verkuil
2017-12-18 14:12 ` jacopo mondi
2017-11-15 10:55 ` [PATCH v1 04/10] ARM: dts: r7s72100: Add Capture Engine Unit (CEU) Jacopo Mondi
2017-11-17 14:22 ` Simon Horman
2017-11-23 9:41 ` Geert Uytterhoeven
2017-11-15 10:55 ` [PATCH v1 05/10] arch: sh: migor: Use new renesas-ceu camera driver Jacopo Mondi
2017-12-11 14:36 ` Laurent Pinchart
2017-12-12 10:00 ` Laurent Pinchart
2017-11-15 10:55 ` [PATCH v1 06/10] sh: sh7722: Rename CEU clock Jacopo Mondi
2017-11-15 13:13 ` Geert Uytterhoeven
2017-11-17 9:15 ` jacopo mondi
2017-11-15 10:56 ` [PATCH v1 07/10] v4l: i2c: Copy ov772x soc_camera sensor driver Jacopo Mondi
2017-12-11 14:49 ` Laurent Pinchart
2017-12-13 12:10 ` Hans Verkuil
2017-12-13 13:02 ` Philippe Ombredanne
2017-11-15 10:56 ` [PATCH v1 08/10] media: i2c: ov772x: Remove soc_camera dependencies Jacopo Mondi
2017-11-17 0:43 ` Sakari Ailus
2017-11-17 9:14 ` jacopo mondi
2017-11-25 16:04 ` Sakari Ailus
2017-12-11 14:47 ` Laurent Pinchart
2017-11-15 10:56 ` [PATCH v1 09/10] v4l: i2c: Copy tw9910 soc_camera sensor driver Jacopo Mondi
2017-12-11 14:50 ` Laurent Pinchart
2017-11-15 10:56 ` [PATCH v1 10/10] media: i2c: tw9910: Remove soc_camera dependencies Jacopo Mondi
2017-12-11 14:55 ` Laurent Pinchart
2017-12-13 12:13 ` Hans Verkuil
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