Re: [PATCH 2/2] Fix capture issues for non 8-bit per pixel formats

From: Guennadi Liakhovetski
Date: Sat Jan 15 2011 - 16:35:42 EST


On Wed, 12 Jan 2011, Alberto Panizzo wrote:

> If the camera was set to output formats like RGB565 YUYV or SBGGR10,
> the resulting image was scrambled due to erroneous interpretations of
> horizontal parameter's units.
>
> This patch in fourcc_to_ipu_pix, eliminate also the pixel formats mappings
> that, first are not used within mainline code and second, standing at
> the datasheets, they will not work properly:
>
> The IPU internal bus support only the following data formatting
> (44.1.1.3 Data Flows and Formats):
> 1 YUV 4:4:4 or RGB-8 bits per color component
> 2 YUV 4:4:4 or RGB-10 bits per color component
> 3 Generic data (from sensor to the system memory only)
>
> And format conversions are done:
> - from memory: de-packing from other formats to IPU supported ones

did you mean "unpacking" (also below)?

> - to memory: packing in the inverse order.
>
> So, assigning a packing/depacking strategy to the IPU for that formats
> will produce a packing to memory and not the inverse.
>
> In the end in mx3_camera_get_formats, is fixed an erroneous debug message
> that try to shows info from an invalid xlate pointer.
>
> Signed-off-by: Alberto Panizzo <maramaopercheseimorto@xxxxxxxxx>
> ---
> drivers/media/video/mx3_camera.c | 66 +++++++++++++++++++++++++++++--------
> 1 files changed, 51 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/media/video/mx3_camera.c b/drivers/media/video/mx3_camera.c
> index b9cb4a4..6b9d019 100644
> --- a/drivers/media/video/mx3_camera.c
> +++ b/drivers/media/video/mx3_camera.c
> @@ -324,14 +324,10 @@ static enum pixel_fmt fourcc_to_ipu_pix(__u32 fourcc)
> {
> /* Add more formats as need arises and test possibilities appear... */
> switch (fourcc) {
> - case V4L2_PIX_FMT_RGB565:
> - return IPU_PIX_FMT_RGB565;
> case V4L2_PIX_FMT_RGB24:
> return IPU_PIX_FMT_RGB24;
> - case V4L2_PIX_FMT_RGB332:
> - return IPU_PIX_FMT_RGB332;
> - case V4L2_PIX_FMT_YUV422P:
> - return IPU_PIX_FMT_YVU422P;
> + case V4L2_PIX_FMT_UYVY:
> + case V4L2_PIX_FMT_RGB565:
> default:
> return IPU_PIX_FMT_GENERIC;
> }
> @@ -359,9 +355,31 @@ static void mx3_videobuf_queue(struct videobuf_queue *vq,
>
> /* This is the configuration of one sg-element */
> video->out_pixel_fmt = fourcc_to_ipu_pix(fourcc);
> - video->out_width = icd->user_width;
> - video->out_height = icd->user_height;
> - video->out_stride = icd->user_width;
> +
> + if (video->out_pixel_fmt == IPU_PIX_FMT_GENERIC) {
> + /*
> + * If the IPU DMA channel is configured to transport
> + * generic 8-bit data, we have to set up correctly the
> + * geometry parameters upon the current pixel format.
> + * So, since the DMA horizontal parameters are expressed
> + * in bytes not pixels, convert these in the right unit.
> + */
> + int bytes_per_line = soc_mbus_bytes_per_line(icd->user_width,
> + icd->current_fmt->host_fmt);
> + BUG_ON(bytes_per_line <= 0);
> +
> + video->out_width = bytes_per_line;
> + video->out_height = icd->user_height;
> + video->out_stride = bytes_per_line;
> + } else {
> + /*
> + * For IPU known formats the pixel unit will be managed
> + * successfully by the IPU code
> + */
> + video->out_width = icd->user_width;
> + video->out_height = icd->user_height;
> + video->out_stride = icd->user_width;
> + }
>
> #ifdef DEBUG
> /* helps to see what DMA actually has written */
> @@ -734,18 +752,36 @@ static int mx3_camera_get_formats(struct soc_camera_device *icd, unsigned int id
> if (xlate) {
> xlate->host_fmt = fmt;
> xlate->code = code;
> + dev_dbg(dev, "Providing format %c%c%c%c in pass-through mode\n",
> + (fmt->fourcc >> (0*8)) & 0xFF,
> + (fmt->fourcc >> (1*8)) & 0xFF,
> + (fmt->fourcc >> (2*8)) & 0xFF,
> + (fmt->fourcc >> (3*8)) & 0xFF);
> xlate++;
> - dev_dbg(dev, "Providing format %x in pass-through mode\n",
> - xlate->host_fmt->fourcc);
> }
>
> return formats;
> }
>
> static void configure_geometry(struct mx3_camera_dev *mx3_cam,
> - unsigned int width, unsigned int height)
> + unsigned int width, unsigned int height,
> + enum v4l2_mbus_pixelcode code)
> {
> u32 ctrl, width_field, height_field;
> + const struct soc_mbus_pixelfmt *fmt;
> +
> + fmt = soc_mbus_get_fmtdesc(code);
> + BUG_ON(!fmt);
> +
> + if (fourcc_to_ipu_pix(fmt->fourcc) == IPU_PIX_FMT_GENERIC) {
> + /*
> + * As the CSI will be configured to output BAYER, here
> + * the width parameter count the number of samples to
> + * capture to complete the whole image width.
> + */
> + width *= soc_mbus_samples_per_pixel(fmt);

Wouldn't

+ width = soc_mbus_bytes_per_line(width, fmt);

produce the same result here? Then we wouldn't need your patch 1/2 at all.

> + BUG_ON(!width);
> + }
>
> /* Setup frame size - this cannot be changed on-the-fly... */
> width_field = width - 1;
> @@ -854,7 +890,7 @@ static int mx3_camera_set_crop(struct soc_camera_device *icd,
> return ret;
> }
>
> - configure_geometry(mx3_cam, mf.width, mf.height);
> + configure_geometry(mx3_cam, mf.width, mf.height, mf.code);
> }
>
> dev_dbg(icd->dev.parent, "Sensor cropped %dx%d\n",
> @@ -897,7 +933,7 @@ static int mx3_camera_set_fmt(struct soc_camera_device *icd,
> * mxc_v4l2_s_fmt()
> */
>
> - configure_geometry(mx3_cam, pix->width, pix->height);
> + configure_geometry(mx3_cam, pix->width, pix->height, xlate->code);
>
> mf.width = pix->width;
> mf.height = pix->height;
> @@ -1152,7 +1188,7 @@ static int mx3_camera_set_bus_param(struct soc_camera_device *icd, __u32 pixfmt)
>
> csi_reg_write(mx3_cam, sens_conf | dw, CSI_SENS_CONF);
>
> - dev_dbg(dev, "Set SENS_CONF to %x\n", sens_conf | dw);
> + dev_info(dev, "Set SENS_CONF to %x\n", sens_conf | dw);

This was unintentional, right?

>
> return 0;
> }
> --
> 1.7.1

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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