Re: [PATCH v2 08/19] media: camss: Add files which handle the video device nodes
From: Hans Verkuil
Date: Thu Jul 06 2017 - 10:43:34 EST
On 07/06/17 15:44, Todor Tomov wrote:
> Hello Hans,
>
> Thank you for the time spent to review.
>
> On 07/03/2017 02:32 PM, Hans Verkuil wrote:
>> On 06/19/2017 04:48 PM, Todor Tomov wrote:
>>> These files handle the video device nodes of the camss driver.
>>>
>>> Signed-off-by: Todor Tomov <todor.tomov@xxxxxxxxxx>
>>> ---
>>> drivers/media/platform/qcom/camss-8x16/video.c | 629 +++++++++++++++++++++++++
>>> drivers/media/platform/qcom/camss-8x16/video.h | 64 +++
>>> 2 files changed, 693 insertions(+)
>>> create mode 100644 drivers/media/platform/qcom/camss-8x16/video.c
>>> create mode 100644 drivers/media/platform/qcom/camss-8x16/video.h
>>>
>>> diff --git a/drivers/media/platform/qcom/camss-8x16/video.c b/drivers/media/platform/qcom/camss-8x16/video.c
>>> new file mode 100644
>>> index 0000000..07175d3
>>> --- /dev/null
>>> +++ b/drivers/media/platform/qcom/camss-8x16/video.c
>>> @@ -0,0 +1,629 @@
>>> +/*
>>> + * video.c
>>> + *
>>> + * Qualcomm MSM Camera Subsystem - V4L2 device node
>>> + *
>>> + * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
>>> + * Copyright (C) 2015-2016 Linaro Ltd.
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify
>>> + * it under the terms of the GNU General Public License version 2 and
>>> + * only version 2 as published by the Free Software Foundation.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>>> + * GNU General Public License for more details.
>>> + */
>>> +#include <linux/slab.h>
>>> +#include <media/media-entity.h>
>>> +#include <media/v4l2-dev.h>
>>> +#include <media/v4l2-device.h>
>>> +#include <media/v4l2-ioctl.h>
>>> +#include <media/v4l2-mc.h>
>>> +#include <media/videobuf-core.h>
>>> +#include <media/videobuf2-dma-sg.h>
>>> +
>>> +#include "video.h"
>>> +#include "camss.h"
>>> +
>>> +/*
>>> + * struct format_info - ISP media bus format information
>>> + * @code: V4L2 media bus format code
>>> + * @pixelformat: V4L2 pixel format FCC identifier
>>> + * @bpp: Bits per pixel when stored in memory
>>> + */
>>> +static const struct format_info {
>>> + u32 code;
>>> + u32 pixelformat;
>>> + unsigned int bpp;
>>> +} formats[] = {
>>> + { MEDIA_BUS_FMT_UYVY8_2X8, V4L2_PIX_FMT_UYVY, 16 },
>>> + { MEDIA_BUS_FMT_VYUY8_2X8, V4L2_PIX_FMT_VYUY, 16 },
>>> + { MEDIA_BUS_FMT_YUYV8_2X8, V4L2_PIX_FMT_YUYV, 16 },
>>> + { MEDIA_BUS_FMT_YVYU8_2X8, V4L2_PIX_FMT_YVYU, 16 },
>>> + { MEDIA_BUS_FMT_SBGGR8_1X8, V4L2_PIX_FMT_SBGGR8, 8 },
>>> + { MEDIA_BUS_FMT_SGBRG8_1X8, V4L2_PIX_FMT_SGBRG8, 8 },
>>> + { MEDIA_BUS_FMT_SGRBG8_1X8, V4L2_PIX_FMT_SGRBG8, 8 },
>>> + { MEDIA_BUS_FMT_SRGGB8_1X8, V4L2_PIX_FMT_SRGGB8, 8 },
>>> + { MEDIA_BUS_FMT_SBGGR10_1X10, V4L2_PIX_FMT_SBGGR10P, 10 },
>>> + { MEDIA_BUS_FMT_SGBRG10_1X10, V4L2_PIX_FMT_SGBRG10P, 10 },
>>> + { MEDIA_BUS_FMT_SGRBG10_1X10, V4L2_PIX_FMT_SGRBG10P, 10 },
>>> + { MEDIA_BUS_FMT_SRGGB10_1X10, V4L2_PIX_FMT_SRGGB10P, 10 },
>>> + { MEDIA_BUS_FMT_SBGGR12_1X12, V4L2_PIX_FMT_SRGGB12P, 12 },
>>> + { MEDIA_BUS_FMT_SGBRG12_1X12, V4L2_PIX_FMT_SGBRG12P, 12 },
>>> + { MEDIA_BUS_FMT_SGRBG12_1X12, V4L2_PIX_FMT_SGRBG12P, 12 },
>>> + { MEDIA_BUS_FMT_SRGGB12_1X12, V4L2_PIX_FMT_SRGGB12P, 12 }
>>> +};
>>> +
>>> +/* -----------------------------------------------------------------------------
>>> + * Helper functions
>>> + */
>>> +
>>> +/*
>>> + * video_mbus_to_pix_mp - Convert v4l2_mbus_framefmt to v4l2_pix_format_mplane
>>> + * @mbus: v4l2_mbus_framefmt format (input)
>>> + * @pix: v4l2_pix_format_mplane format (output)
>>> + *
>>> + * Fill the output pix structure with information from the input mbus format.
>>> + *
>>> + * Return 0 on success or a negative error code otherwise
>>> + */
>>> +static unsigned int video_mbus_to_pix_mp(const struct v4l2_mbus_framefmt *mbus,
>>> + struct v4l2_pix_format_mplane *pix)
>>> +{
>>> + unsigned int i;
>>> + u32 bytesperline;
>>> +
>>> + memset(pix, 0, sizeof(*pix));
>>> + pix->width = mbus->width;
>>> + pix->height = mbus->height;
>>> +
>>> + for (i = 0; i < ARRAY_SIZE(formats); ++i) {
>>> + if (formats[i].code == mbus->code)
>>> + break;
>>> + }
>>> +
>>> + if (WARN_ON(i == ARRAY_SIZE(formats)))
>>> + return -EINVAL;
>>> +
>>> + pix->pixelformat = formats[i].pixelformat;
>>> + pix->num_planes = 1;
>>> + bytesperline = pix->width * formats[i].bpp / 8;
>>> + bytesperline = ALIGN(bytesperline, 8);
>>> + pix->plane_fmt[0].bytesperline = bytesperline;
>>> + pix->plane_fmt[0].sizeimage = bytesperline * pix->height;
>>> + pix->colorspace = mbus->colorspace;
>>> + pix->field = mbus->field;
>>> +
>>> + return 0;
>>> +}
>>
>> Can you add a v4l2_fill_pix_format_mplane and a v4l2_fill_mbus_format_mplane
>> static inline to media/v4l2-mediabus.h?
>>
>> And use v4l2_fill_pix_format_mplane() here?
>
> The problem is what to do with the mbus code <=> pixelformat matching? In this
> version of the driver all used formats can be 1 to 1 matched however this is
> not always true. E. g. in the later versions (patch 11/19: Format conversion support
> using PIX interface) the MEDIA_BUS_FMT_UYVY8_2X8 can be matched to V4L2_PIX_FMT_UYVY,
> V4L2_PIX_FMT_NV16 or V4L2_PIX_FMT_NV61. To make it more complex, depending on
> the hw configuiration (which is done based on the media pipeline configuration)
> not all can be possible, e.g. in one case only NV16/NV61 can be selected but not
> V4L2_PIX_FMT_UYVY; and in another case - only V4L2_PIX_FMT_UYVY can be selected.
> To handle this, in the driver I have used:
> - a "suggestion" from the userspace on which format to select;
> - an additional field in the matching table called "tag" which indicates which one
> it is allowed to select for the current case.
> However I'm not sure that it will be practical to implement this as a generic function.
> On the other case if there is a generic way to handle this, it will be useful.
> Another issue could be multiple mbus code choices for a single pixelformat -
> maybe such cases are also possible?
If you look at the v4l2_fill_pix/mbus_format functions in include/media/v4l2-mediabus.h
you'll see that they don't do anything with pixelformat and mbus code. There are just
simple functions that transfer fields that are the same for both struct from one to
the other. That's all :-)
Rather than doing this same thing for each multiplanar driver it is better to refactor
a bit and add new helper functions.
>
>>
>>> +
>>> +static struct v4l2_subdev *video_remote_subdev(struct camss_video *video,
>>> + u32 *pad)
>>> +{
>>> + struct media_pad *remote;
>>> +
>>> + remote = media_entity_remote_pad(&video->pad);
>>> +
>>> + if (!remote || !is_media_entity_v4l2_subdev(remote->entity))
>>> + return NULL;
>>> +
>>> + if (pad)
>>> + *pad = remote->index;
>>> +
>>> + return media_entity_to_v4l2_subdev(remote->entity);
>>> +}
>>> +
>>> +static int video_get_subdev_format(struct camss_video *video,
>>> + struct v4l2_format *format)
>>> +{
>>> + struct v4l2_subdev_format fmt;
>>> + struct v4l2_subdev *subdev;
>>> + u32 pad;
>>> + int ret;
>>> +
>>> + subdev = video_remote_subdev(video, &pad);
>>> + if (subdev == NULL)
>>> + return -EINVAL;
>>> +
>>> + fmt.pad = pad;
>>> + fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
>>> +
>>> + ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + format->type = video->type;
>>> + return video_mbus_to_pix_mp(&fmt.format, &format->fmt.pix_mp);
>>> +}
>>> +
>>> +/* -----------------------------------------------------------------------------
>>> + * Video queue operations
>>> + */
>>> +
>>> +static int video_queue_setup(struct vb2_queue *q,
>>> + unsigned int *num_buffers, unsigned int *num_planes,
>>> + unsigned int sizes[], struct device *alloc_devs[])
>>> +{
>>> + struct camss_video *video = vb2_get_drv_priv(q);
>>> +
>>> + if (*num_planes) {
>>> + if (*num_planes != 1)
>>> + return -EINVAL;
>>> +
>>> + if (sizes[0] < video->active_fmt.fmt.pix_mp.plane_fmt[0].sizeimage)
>>> + return -EINVAL;
>>> +
>>> + return 0;
>>> + }
>>> +
>>> + *num_planes = 1;
>>> +
>>> + sizes[0] = video->active_fmt.fmt.pix_mp.plane_fmt[0].sizeimage;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int video_buf_prepare(struct vb2_buffer *vb)
>>> +{
>>> + struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
>>> + struct camss_video *video = vb2_get_drv_priv(vb->vb2_queue);
>>> + struct camss_buffer *buffer = container_of(vbuf, struct camss_buffer,
>>> + vb);
>>> + struct sg_table *sgt;
>>> +
>>> + if (video->active_fmt.fmt.pix_mp.plane_fmt[0].sizeimage >
>>> + vb2_plane_size(vb, 0))
>>> + return -EINVAL;
>>> +
>>> + vb2_set_plane_payload(vb, 0,
>>> + video->active_fmt.fmt.pix_mp.plane_fmt[0].sizeimage);
>>> +
>>> + sgt = vb2_dma_sg_plane_desc(vb, 0);
>>> + if (!sgt)
>>> + return -EFAULT;
>>> +
>>> + buffer->addr = sg_dma_address(sgt->sgl);
>>> +
>>> + vbuf->field = V4L2_FIELD_NONE;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static void video_buf_queue(struct vb2_buffer *vb)
>>> +{
>>> + struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
>>> + struct camss_video *video = vb2_get_drv_priv(vb->vb2_queue);
>>> + struct camss_buffer *buffer = container_of(vbuf, struct camss_buffer,
>>> + vb);
>>> +
>>> + video->ops->queue_buffer(video, buffer);
>>> +}
>>> +
>>> +static int video_check_format(struct camss_video *video)
>>> +{
>>> + struct v4l2_pix_format_mplane *pix = &video->active_fmt.fmt.pix_mp;
>>> + struct v4l2_pix_format_mplane *sd_pix;
>>> + struct v4l2_format format;
>>> + int ret;
>>> +
>>> + ret = video_get_subdev_format(video, &format);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + sd_pix = &format.fmt.pix_mp;
>>> + if (pix->pixelformat != sd_pix->pixelformat ||
>>> + pix->height != sd_pix->height ||
>>> + pix->width != sd_pix->width ||
>>> + pix->num_planes != sd_pix->num_planes ||
>>> + pix->plane_fmt[0].bytesperline != sd_pix->plane_fmt[0].bytesperline ||
>>> + pix->plane_fmt[0].sizeimage != sd_pix->plane_fmt[0].sizeimage ||
>>> + pix->field != format.fmt.pix_mp.field)
>>> + return -EINVAL;
>>
>> This check is only valid if num_planes == 1.
>>
>> Either improve the check so it can handle more planes, or add a 'pix->num_planes != 1'
>> check.
>
> Yes, in this initial version the driver uses the multi-plane API but only supports
> single plane formats (the hardware is configured in such a way that only single plane
> formats are possible). This is why I have left this here and on other places for the
> first plane only. Then patch 11/19 (Format conversion support using PIX interface)
> fixes this and does it for all planes. Is it ok to leave it like this?
Since you need to make some changes here anyway I would prefer it if you add
a 'pix->num_planes != 1 ||' line here. That can be removed again in patch 11/19.
It's not a blocker, but it is cleaner that way.
>
>>
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int video_start_streaming(struct vb2_queue *q, unsigned int count)
>>> +{
>>> + struct camss_video *video = vb2_get_drv_priv(q);
>>> + struct video_device *vdev = &video->vdev;
>>> + struct media_entity *entity;
>>> + struct media_pad *pad;
>>> + struct v4l2_subdev *subdev;
>>> + int ret;
>>> +
>>> + ret = media_pipeline_start(&vdev->entity, &video->pipe);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + ret = video_check_format(video);
>>> + if (ret < 0)
>>> + goto error;
>>> +
>>> + entity = &vdev->entity;
>>> + while (1) {
>>> + pad = &entity->pads[0];
>>> + if (!(pad->flags & MEDIA_PAD_FL_SINK))
>>> + break;
>>> +
>>> + pad = media_entity_remote_pad(pad);
>>> + if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
>>> + break;
>>> +
>>> + entity = pad->entity;
>>> + subdev = media_entity_to_v4l2_subdev(entity);
>>> +
>>> + ret = v4l2_subdev_call(subdev, video, s_stream, 1);
>>> + if (ret < 0 && ret != -ENOIOCTLCMD)
>>> + goto error;
>>> + }
>>> +
>>> + return 0;
>>> +
>>> +error:
>>> + media_pipeline_stop(&vdev->entity);
>>> +
>>> + video->ops->flush_buffers(video, VB2_BUF_STATE_QUEUED);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static void video_stop_streaming(struct vb2_queue *q)
>>> +{
>>> + struct camss_video *video = vb2_get_drv_priv(q);
>>> + struct video_device *vdev = &video->vdev;
>>> + struct media_entity *entity;
>>> + struct media_pad *pad;
>>> + struct v4l2_subdev *subdev;
>>> + struct v4l2_subdev *subdev_vfe = NULL;
>>> +
>>> + entity = &vdev->entity;
>>> + while (1) {
>>> + pad = &entity->pads[0];
>>> + if (!(pad->flags & MEDIA_PAD_FL_SINK))
>>> + break;
>>> +
>>> + pad = media_entity_remote_pad(pad);
>>> + if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
>>> + break;
>>> +
>>> + entity = pad->entity;
>>> + subdev = media_entity_to_v4l2_subdev(entity);
>>> +
>>> + if (strstr(subdev->name, "vfe")) {
>>> + subdev_vfe = subdev;
>>> + } else if (strstr(subdev->name, "ispif")) {
>>> + v4l2_subdev_call(subdev, video, s_stream, 0);
>>> + v4l2_subdev_call(subdev_vfe, video, s_stream, 0);
>>> + } else {
>>> + v4l2_subdev_call(subdev, video, s_stream, 0);
>>> + }
>>> + }
>>> +
>>> + media_pipeline_stop(&vdev->entity);
>>> +
>>> + video->ops->flush_buffers(video, VB2_BUF_STATE_ERROR);
>>> +}
>>> +
>>> +static const struct vb2_ops msm_video_vb2_q_ops = {
>>> + .queue_setup = video_queue_setup,
>>> + .wait_prepare = vb2_ops_wait_prepare,
>>> + .wait_finish = vb2_ops_wait_finish,
>>> + .buf_prepare = video_buf_prepare,
>>> + .buf_queue = video_buf_queue,
>>> + .start_streaming = video_start_streaming,
>>> + .stop_streaming = video_stop_streaming,
>>> +};
>>> +
>>> +/* -----------------------------------------------------------------------------
>>> + * V4L2 ioctls
>>> + */
>>> +
>>> +static int video_querycap(struct file *file, void *fh,
>>> + struct v4l2_capability *cap)
>>> +{
>>> + struct camss_video *video = video_drvdata(file);
>>> +
>>> + strlcpy(cap->driver, "qcom-camss", sizeof(cap->driver));
>>> + strlcpy(cap->card, "Qualcomm Camera Subsystem", sizeof(cap->card));
>>> + snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
>>> + dev_name(video->camss->dev));
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int video_enum_fmt(struct file *file, void *fh, struct v4l2_fmtdesc *f)
>>> +{
>>> + struct camss_video *video = video_drvdata(file);
>>> + struct v4l2_format format;
>>> + int ret;
>>> +
>>> + if (f->type != video->type)
>>> + return -EINVAL;
>>> +
>>> + if (f->index)
>>> + return -EINVAL;
>>> +
>>> + ret = video_get_subdev_format(video, &format);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + f->pixelformat = format.fmt.pix.pixelformat;
>>
>> Shouldn't this be format.fmt.pix_mp.pixelformat?
>
> Yes. I'll fix it.
>
>>
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int video_g_fmt(struct file *file, void *fh, struct v4l2_format *f)
>>> +{
>>> + struct camss_video *video = video_drvdata(file);
>>> +
>>> + if (f->type != video->type)
>>> + return -EINVAL;
>>
>> I don't think this check is necessary. Same for s/try_fmt.
>> f->type will always be VIDEO_CAPTURE_MPLANE.
>
> Ok.
>
>>
>>> +
>>> + *f = video->active_fmt;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int video_s_fmt(struct file *file, void *fh, struct v4l2_format *f)
>>> +{
>>> + struct camss_video *video = video_drvdata(file);
>>> + int ret;
>>> +
>>> + if (f->type != video->type)
>>> + return -EINVAL;
>>> +
>>
>> You need to add:
>>
>> if (vb2_is_busy(...))
>> return -EBUSY;
>
> Ok.
>
>>
>>> + ret = video_get_subdev_format(video, f);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + video->active_fmt = *f;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int video_try_fmt(struct file *file, void *fh, struct v4l2_format *f)
>>> +{
>>> + struct camss_video *video = video_drvdata(file);
>>> +
>>> + if (f->type != video->type)
>>> + return -EINVAL;
>>> +
>>> + return video_get_subdev_format(video, f);
>>> +}
>>> +
>>> +static int video_enum_input(struct file *file, void *fh,
>>> + struct v4l2_input *input)
>>> +{
>>> + if (input->index > 0)
>>> + return -EINVAL;
>>> +
>>> + strlcpy(input->name, "camera", sizeof(input->name));
>>> + input->type = V4L2_INPUT_TYPE_CAMERA;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int video_g_input(struct file *file, void *fh, unsigned int *input)
>>> +{
>>> + *input = 0;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int video_s_input(struct file *file, void *fh, unsigned int input)
>>> +{
>>> + return input == 0 ? 0 : -EINVAL;
>>> +}
>>> +
>>> +static const struct v4l2_ioctl_ops msm_vid_ioctl_ops = {
>>> + .vidioc_querycap = video_querycap,
>>> + .vidioc_enum_fmt_vid_cap_mplane = video_enum_fmt,
>>> + .vidioc_g_fmt_vid_cap_mplane = video_g_fmt,
>>> + .vidioc_s_fmt_vid_cap_mplane = video_s_fmt,
>>> + .vidioc_try_fmt_vid_cap_mplane = video_try_fmt,
>>> + .vidioc_reqbufs = vb2_ioctl_reqbufs,
>>> + .vidioc_querybuf = vb2_ioctl_querybuf,
>>> + .vidioc_qbuf = vb2_ioctl_qbuf,
>>> + .vidioc_expbuf = vb2_ioctl_expbuf,
>>> + .vidioc_dqbuf = vb2_ioctl_dqbuf,
>>> + .vidioc_create_bufs = vb2_ioctl_create_bufs,
>>> + .vidioc_prepare_buf = vb2_ioctl_prepare_buf,
>>> + .vidioc_streamon = vb2_ioctl_streamon,
>>> + .vidioc_streamoff = vb2_ioctl_streamoff,
>>> + .vidioc_enum_input = video_enum_input,
>>> + .vidioc_g_input = video_g_input,
>>> + .vidioc_s_input = video_s_input,
>>> +};
>>> +
>>> +/* -----------------------------------------------------------------------------
>>> + * V4L2 file operations
>>> + */
>>> +
>>> +/*
>>> + * video_init_format - Helper function to initialize format
>>> + *
>>> + * Initialize all pad formats with default values.
>>> + */
>>> +static int video_init_format(struct file *file, void *fh)
>>> +{
>>> + struct v4l2_format format;
>>> +
>>> + memset(&format, 0, sizeof(format));
>>> + format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
>>> +
>>> + return video_s_fmt(file, fh, &format);
>>> +}
>>> +
>>> +static int video_open(struct file *file)
>>> +{
>>> + struct video_device *vdev = video_devdata(file);
>>> + struct camss_video *video = video_drvdata(file);
>>> + struct v4l2_fh *vfh;
>>> + int ret;
>>> +
>>> + mutex_lock(&video->lock);
>>> +
>>> + vfh = kzalloc(sizeof(*vfh), GFP_KERNEL);
>>> + if (vfh == NULL) {
>>> + ret = -ENOMEM;
>>> + goto error_alloc;
>>> + }
>>> +
>>> + v4l2_fh_init(vfh, vdev);
>>> + v4l2_fh_add(vfh);
>>> +
>>> + file->private_data = vfh;
>>> +
>>> + ret = v4l2_pipeline_pm_use(&vdev->entity, 1);
>>
>>
>>> + if (ret < 0) {
>>> + dev_err(video->camss->dev, "Failed to power up pipeline\n");
>>> + goto error_pm_use;
>>> + }
>>> +
>>> + ret = video_init_format(file, vfh);
>>
>> This is wrong. The format is for the video_device, not per filehandle.
>> If a capture is in progress on one filehandle, you should still be able to call:
>>
>> v4l2-ctl --all
>>
>> to see what the current format etc. is.
>>
>> With this code the format would be overwritten.
>
> Yes, this is true.
>
>>
>> As far as I can tell you can just drop this call. I don't see what purpose it
>> serves.
>
> My intention was to initialize the format to some meaningful value. If this is not
> needed then I can drop it. Otherwise I have to change it to something which will
> really run only once, not run on every open.
The format is a global thing, not a per-filehandle thing.
It has to be initialized, but that happens when the driver is initialized.
Basically after loading the driver and running v4l2-ctl --all it should all
look valid. v4l2-compliance tests the same thing.
>
>>
>>> + if (ret < 0) {
>>> + dev_err(video->camss->dev, "Failed to init format\n");
>>> + goto error_init_format;
>>> + }
>>> +
>>> + mutex_unlock(&video->lock);
>>> +
>>> + return 0;
>>> +
>>> +error_init_format:
>>> + v4l2_pipeline_pm_use(&vdev->entity, 0);
>>> +
>>> +error_pm_use:
>>> + v4l2_fh_release(file);
>>> +
>>> +error_alloc:
>>> + mutex_unlock(&video->lock);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int video_release(struct file *file)
>>> +{
>>> + struct video_device *vdev = video_devdata(file);
>>> +
>>> + vb2_fop_release(file);
>>> +
>>> + v4l2_pipeline_pm_use(&vdev->entity, 0);
>>> +
>>> + file->private_data = NULL;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct v4l2_file_operations msm_vid_fops = {
>>> + .owner = THIS_MODULE,
>>> + .unlocked_ioctl = video_ioctl2,
>>> + .open = video_open,
>>> + .release = video_release,
>>> + .poll = vb2_fop_poll,
>>> + .mmap = vb2_fop_mmap,
>>> + .read = vb2_fop_read,
>>> +};
>>> +
>>> +/* -----------------------------------------------------------------------------
>>> + * CAMSS video core
>>> + */
>>> +
>>> +static void msm_video_release(struct video_device *vdev)
>>> +{
>>> + struct camss_video *video = video_get_drvdata(vdev);
>>> +
>>> + media_entity_cleanup(&vdev->entity);
>>> +
>>> + mutex_destroy(&video->q_lock);
>>> + mutex_destroy(&video->lock);
>>> +
>>> + if (atomic_dec_and_test(&video->camss->ref_count))
>>> + camss_delete(video->camss);
>>> +}
>>> +
>>> +int msm_video_register(struct camss_video *video, struct v4l2_device *v4l2_dev,
>>> + const char *name)
>>> +{
>>> + struct media_pad *pad = &video->pad;
>>> + struct video_device *vdev;
>>> + struct vb2_queue *q;
>>> + int ret;
>>> +
>>> + vdev = &video->vdev;
>>> +
>>> + mutex_init(&video->q_lock);
>>> +
>>> + q = &video->vb2_q;
>>> + q->drv_priv = video;
>>> + q->mem_ops = &vb2_dma_sg_memops;
>>> + q->ops = &msm_video_vb2_q_ops;
>>> + q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
>>> + q->io_modes = VB2_DMABUF | VB2_MMAP | VB2_READ;
>>> + q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
>>> + q->buf_struct_size = sizeof(struct camss_buffer);
>>> + q->dev = video->camss->dev;
>>> + q->lock = &video->q_lock;
>>> + ret = vb2_queue_init(q);
>>> + if (ret < 0) {
>>> + dev_err(v4l2_dev->dev, "Failed to init vb2 queue\n");
>>> + goto error_vb2_init;
>>> + }
>>> +
>>> + pad->flags = MEDIA_PAD_FL_SINK;
>>> + ret = media_entity_pads_init(&vdev->entity, 1, pad);
>>> + if (ret < 0) {
>>> + dev_err(v4l2_dev->dev, "Failed to init video entity\n");
>>> + goto error_media_init;
>>> + }
>>> +
>>> + mutex_init(&video->lock);
>>> +
>>> + vdev->fops = &msm_vid_fops;
>>> + vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE_MPLANE | V4L2_CAP_STREAMING |
>>> + V4L2_CAP_READWRITE;
>>> + vdev->ioctl_ops = &msm_vid_ioctl_ops;
>>> + vdev->release = msm_video_release;
>>> + vdev->v4l2_dev = v4l2_dev;
>>> + vdev->vfl_dir = VFL_DIR_RX;
>>> + vdev->queue = &video->vb2_q;
>>> + vdev->lock = &video->lock;
>>> + strlcpy(vdev->name, name, sizeof(vdev->name));
>>> +
>>> + ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
>>> + if (ret < 0) {
>>> + dev_err(v4l2_dev->dev, "Failed to register video device\n");
>>> + goto error_video_register;
>>> + }
>>> +
>>> + video_set_drvdata(vdev, video);
>>> + atomic_inc(&video->camss->ref_count);
>>> +
>>> + return 0;
>>> +
>>> +error_video_register:
>>> + media_entity_cleanup(&vdev->entity);
>>> + mutex_destroy(&video->lock);
>>> +error_media_init:
>>> + vb2_queue_release(&video->vb2_q);
>>> +error_vb2_init:
>>> + mutex_destroy(&video->q_lock);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +void msm_video_stop_streaming(struct camss_video *video)
>>> +{
>>> + if (vb2_is_streaming(&video->vb2_q))
>>> + vb2_queue_release(&video->vb2_q);
>>> +}
>>> +
>>> +void msm_video_unregister(struct camss_video *video)
>>> +{
>>> + atomic_inc(&video->camss->ref_count);
>>> + video_unregister_device(&video->vdev);
>>> + atomic_dec(&video->camss->ref_count);
>>> +}
>>> diff --git a/drivers/media/platform/qcom/camss-8x16/video.h b/drivers/media/platform/qcom/camss-8x16/video.h
>>> new file mode 100644
>>> index 0000000..9ad7bbc
>>> --- /dev/null
>>> +++ b/drivers/media/platform/qcom/camss-8x16/video.h
>>> @@ -0,0 +1,64 @@
>>> +/*
>>> + * video.h
>>> + *
>>> + * Qualcomm MSM Camera Subsystem - V4L2 device node
>>> + *
>>> + * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
>>> + * Copyright (C) 2015-2016 Linaro Ltd.
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify
>>> + * it under the terms of the GNU General Public License version 2 and
>>> + * only version 2 as published by the Free Software Foundation.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>>> + * GNU General Public License for more details.
>>> + */
>>> +#ifndef QC_MSM_CAMSS_VIDEO_H
>>> +#define QC_MSM_CAMSS_VIDEO_H
>>> +
>>> +#include <linux/mutex.h>
>>> +#include <linux/videodev2.h>
>>> +#include <media/media-entity.h>
>>> +#include <media/v4l2-dev.h>
>>> +#include <media/v4l2-device.h>
>>> +#include <media/v4l2-fh.h>
>>> +#include <media/v4l2-mediabus.h>
>>> +#include <media/videobuf2-v4l2.h>
>>> +
>>> +struct camss_buffer {
>>> + struct vb2_v4l2_buffer vb;
>>> + dma_addr_t addr;
>>> + struct list_head queue;
>>> +};
>>> +
>>> +struct camss_video;
>>> +
>>> +struct camss_video_ops {
>>> + int (*queue_buffer)(struct camss_video *vid, struct camss_buffer *buf);
>>> + int (*flush_buffers)(struct camss_video *vid,
>>> + enum vb2_buffer_state state);
>>> +};
>>> +
>>> +struct camss_video {
>>> + struct camss *camss;
>>> + struct vb2_queue vb2_q;
>>> + struct video_device vdev;
>>> + struct media_pad pad;
>>> + struct v4l2_format active_fmt;
>>> + enum v4l2_buf_type type;
>>> + struct media_pipeline pipe;
>>> + const struct camss_video_ops *ops;
>>> + struct mutex lock;
>>> + struct mutex q_lock;
>>> +};
>>> +
>>> +void msm_video_stop_streaming(struct camss_video *video);
>>> +
>>> +int msm_video_register(struct camss_video *video, struct v4l2_device *v4l2_dev,
>>> + const char *name);
>>> +
>>> +void msm_video_unregister(struct camss_video *video);
>>
>> I'm a bit confused who is calling these functions. The relationship between
>> the video file and the vfe file is a bit obscure.
>>
>> Can you add some comments here?
>
> The vfe file handles the hardware configuration of the VFE hw module as well as handles
> the subdev node which represents the VFE. The video file handles only the video
> device node (which is connected to the subdevice node of the VFE). Only after the subdev
> node is registered from vfe file, msm_video_register() is called to initialize and
> register the video device node.
> I'll add short comments here and in the caller functions.
>
>>
>>> +
>>> +#endif /* QC_MSM_CAMSS_VIDEO_H */
>>>
>>
>> Regards,
>>
>> Hans
>
Regards,
Hans