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Subject: Re: [PATCH] media: stm32-dcmi: add JPEG support
To:     Hugues Fruchet <hugues.fruchet@st.com>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>
Cc:     linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org,
        Benjamin Gaignard <benjamin.gaignard@linaro.org>,
        Yannick Fertre <yannick.fertre@st.com>
References: <1519293110-20059-1-git-send-email-hugues.fruchet@st.com>
From:   Hans Verkuil <hverkuil@xs4all.nl>
Message-ID: <a0e231ee-b125-97b6-80a5-2f82c7299070@xs4all.nl>
Date:   Mon, 26 Feb 2018 15:17:01 +0100
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On 02/22/2018 10:51 AM, Hugues Fruchet wrote:
> Add DCMI JPEG support.

Does this patch depend on the 'fix lock scheme' patch?

It looks good to me except for one small thing (see below), but I think this
depends on the 'fix lock scheme' patch, right?

> 
> Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
> ---
>  drivers/media/platform/stm32/stm32-dcmi.c | 195 +++++++++++++++++++++++-------
>  1 file changed, 148 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
> index 269e963..7eaaf7c 100644
> --- a/drivers/media/platform/stm32/stm32-dcmi.c
> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
> @@ -93,6 +93,11 @@ enum state {
>  #define MIN_HEIGHT	16U
>  #define MAX_HEIGHT	2048U
>  
> +#define MIN_JPEG_WIDTH	16U
> +#define MAX_JPEG_WIDTH	2592U
> +#define MIN_JPEG_HEIGHT	16U
> +#define MAX_JPEG_HEIGHT	2592U
> +
>  #define TIMEOUT_MS	1000
>  
>  struct dcmi_graph_entity {
> @@ -191,14 +196,67 @@ static inline void reg_clear(void __iomem *base, u32 reg, u32 mask)
>  
>  static int dcmi_start_capture(struct stm32_dcmi *dcmi);
>  
> +static void dcmi_buffer_done(struct stm32_dcmi *dcmi,
> +			     struct dcmi_buf *buf,
> +			     size_t bytesused,
> +			     int err)
> +{
> +	struct vb2_v4l2_buffer *vbuf;
> +
> +	if (!buf)
> +		return;
> +
> +	vbuf = &buf->vb;
> +
> +	vbuf->sequence = dcmi->sequence++;
> +	vbuf->field = V4L2_FIELD_NONE;
> +	vbuf->vb2_buf.timestamp = ktime_get_ns();
> +	vb2_set_plane_payload(&vbuf->vb2_buf, 0, bytesused);
> +	vb2_buffer_done(&vbuf->vb2_buf,
> +			err ? VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
> +	dev_dbg(dcmi->dev, "buffer[%d] done seq=%d, bytesused=%zu\n",
> +		vbuf->vb2_buf.index, vbuf->sequence, bytesused);
> +
> +	dcmi->buffers_count++;
> +	dcmi->active = NULL;
> +}
> +
> +static int dcmi_restart_capture(struct stm32_dcmi *dcmi)
> +{
> +	spin_lock_irq(&dcmi->irqlock);
> +
> +	if (dcmi->state != RUNNING) {
> +		spin_unlock_irq(&dcmi->irqlock);
> +		return -EINVAL;
> +	}
> +
> +	/* Restart a new DMA transfer with next buffer */
> +	if (list_empty(&dcmi->buffers)) {
> +		dev_err(dcmi->dev, "%s: No more buffer queued, cannot capture buffer\n",
> +			__func__);
> +		dcmi->errors_count++;
> +		dcmi->active = NULL;
> +
> +		spin_unlock_irq(&dcmi->irqlock);
> +		return -EINVAL;
> +	}
> +
> +	dcmi->active = list_entry(dcmi->buffers.next,
> +				  struct dcmi_buf, list);
> +	list_del_init(&dcmi->active->list);
> +
> +	spin_unlock_irq(&dcmi->irqlock);
> +
> +	return dcmi_start_capture(dcmi);
> +}
> +
>  static void dcmi_dma_callback(void *param)
>  {
>  	struct stm32_dcmi *dcmi = (struct stm32_dcmi *)param;
>  	struct dma_chan *chan = dcmi->dma_chan;
>  	struct dma_tx_state state;
>  	enum dma_status status;
> -
> -	spin_lock_irq(&dcmi->irqlock);
> +	struct dcmi_buf *buf = dcmi->active;
>  
>  	/* Check DMA status */
>  	status = dmaengine_tx_status(chan, dcmi->dma_cookie, &state);
> @@ -216,53 +274,18 @@ static void dcmi_dma_callback(void *param)
>  	case DMA_COMPLETE:
>  		dev_dbg(dcmi->dev, "%s: Received DMA_COMPLETE\n", __func__);
>  
> -		if (dcmi->active) {
> -			struct dcmi_buf *buf = dcmi->active;
> -			struct vb2_v4l2_buffer *vbuf = &dcmi->active->vb;
> -
> -			vbuf->sequence = dcmi->sequence++;
> -			vbuf->field = V4L2_FIELD_NONE;
> -			vbuf->vb2_buf.timestamp = ktime_get_ns();
> -			vb2_set_plane_payload(&vbuf->vb2_buf, 0, buf->size);
> -			vb2_buffer_done(&vbuf->vb2_buf, VB2_BUF_STATE_DONE);
> -			dev_dbg(dcmi->dev, "buffer[%d] done seq=%d\n",
> -				vbuf->vb2_buf.index, vbuf->sequence);
> -
> -			dcmi->buffers_count++;
> -			dcmi->active = NULL;
> -		}
> -
> -		/* Restart a new DMA transfer with next buffer */
> -		if (dcmi->state == RUNNING) {
> -			if (list_empty(&dcmi->buffers)) {
> -				dev_err(dcmi->dev, "%s: No more buffer queued, cannot capture buffer\n",
> -					__func__);
> -				dcmi->errors_count++;
> -				dcmi->active = NULL;
> -
> -				spin_unlock_irq(&dcmi->irqlock);
> -				return;
> -			}
> -
> -			dcmi->active = list_entry(dcmi->buffers.next,
> -						  struct dcmi_buf, list);
> -
> -			list_del_init(&dcmi->active->list);
> -
> -			spin_unlock_irq(&dcmi->irqlock);
> -			if (dcmi_start_capture(dcmi))
> -				dev_err(dcmi->dev, "%s: Cannot restart capture on DMA complete\n",
> -					__func__);
> -			return;
> -		}
> +		/* Return buffer to V4L2 */
> +		dcmi_buffer_done(dcmi, buf, buf->size, 0);
>  
> +		/* Restart capture */
> +		if (dcmi_restart_capture(dcmi))
> +			dev_err(dcmi->dev, "%s: Cannot restart capture on DMA complete\n",
> +				__func__);
>  		break;
>  	default:
>  		dev_err(dcmi->dev, "%s: Received unknown status\n", __func__);
>  		break;
>  	}
> -
> -	spin_unlock_irq(&dcmi->irqlock);
>  }
>  
>  static int dcmi_start_dma(struct stm32_dcmi *dcmi,
> @@ -355,6 +378,52 @@ static void dcmi_set_crop(struct stm32_dcmi *dcmi)
>  	reg_set(dcmi->regs, DCMI_CR, CR_CROP);
>  }
>  
> +static void dcmi_process_jpeg(struct stm32_dcmi *dcmi)
> +{
> +	struct dma_tx_state state;
> +	enum dma_status status;
> +	struct dma_chan *chan = dcmi->dma_chan;
> +	struct dcmi_buf *buf = dcmi->active;
> +
> +	if (!buf)
> +		return;
> +
> +	/*
> +	 * Because of variable JPEG buffer size sent by sensor,
> +	 * DMA transfer never completes due to transfer size
> +	 * never reached.
> +	 * In order to ensure that all the JPEG data are transferred
> +	 * in active buffer memory, DMA is drained.
> +	 * Then DMA tx status gives the amount of data transferred
> +	 * to memory, which is then returned to V4L2 through the active
> +	 * buffer payload.
> +	 */
> +
> +	/* Drain DMA */
> +	dmaengine_synchronize(chan);
> +
> +	/* Get DMA residue to get JPEG size */
> +	status = dmaengine_tx_status(chan, dcmi->dma_cookie, &state);
> +	if (status != DMA_ERROR && state.residue < buf->size) {
> +		/* Return JPEG buffer to V4L2 with received JPEG buffer size */
> +		dcmi_buffer_done(dcmi, buf, buf->size - state.residue, 0);
> +	} else {
> +		dcmi->errors_count++;
> +		dev_err(dcmi->dev, "%s: Cannot get JPEG size from DMA\n",
> +			__func__);
> +		/* Return JPEG buffer to V4L2 in ERROR state */
> +		dcmi_buffer_done(dcmi, buf, 0, -EIO);
> +	}
> +
> +	/* Abort DMA operation */
> +	dmaengine_terminate_all(dcmi->dma_chan);
> +
> +	/* Restart capture */
> +	if (dcmi_restart_capture(dcmi))
> +		dev_err(dcmi->dev, "%s: Cannot restart capture on JPEG received\n",
> +			__func__);
> +}
> +
>  static irqreturn_t dcmi_irq_thread(int irq, void *arg)
>  {
>  	struct stm32_dcmi *dcmi = arg;
> @@ -379,6 +448,14 @@ static irqreturn_t dcmi_irq_thread(int irq, void *arg)
>  			dcmi->overrun_count++;
>  	}
>  
> +	if (dcmi->sd_format->fourcc == V4L2_PIX_FMT_JPEG &&
> +	    dcmi->misr & IT_FRAME) {
> +		/* JPEG received */
> +		spin_unlock_irq(&dcmi->irqlock);
> +		dcmi_process_jpeg(dcmi);
> +		return IRQ_HANDLED;
> +	}
> +
>  	spin_unlock_irq(&dcmi->irqlock);
>  	return IRQ_HANDLED;
>  }
> @@ -552,6 +629,10 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	if (dcmi->do_crop)
>  		dcmi_set_crop(dcmi);
>  
> +	/* Enable jpeg capture */
> +	if (dcmi->sd_format->fourcc == V4L2_PIX_FMT_JPEG)
> +		reg_set(dcmi->regs, DCMI_CR, CR_CM);/* Snapshot mode */
> +
>  	/* Enable dcmi */
>  	reg_set(dcmi->regs, DCMI_CR, CR_ENABLE);
>  
> @@ -752,6 +833,7 @@ static int dcmi_try_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f,
>  	struct v4l2_subdev_format format = {
>  		.which = V4L2_SUBDEV_FORMAT_TRY,
>  	};
> +	bool do_crop;
>  	int ret;
>  
>  	sd_fmt = find_format_by_fourcc(dcmi, pix->pixelformat);
> @@ -761,10 +843,19 @@ static int dcmi_try_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f,
>  	}
>  
>  	/* Limit to hardware capabilities */
> -	pix->width = clamp(pix->width, MIN_WIDTH, MAX_WIDTH);
> -	pix->height = clamp(pix->height, MIN_HEIGHT, MAX_HEIGHT);
> +	if (pix->pixelformat == V4L2_PIX_FMT_JPEG) {
> +		pix->width = clamp(pix->width, MIN_JPEG_WIDTH, MAX_JPEG_WIDTH);
> +		pix->height =
> +			clamp(pix->height, MIN_JPEG_HEIGHT, MAX_JPEG_HEIGHT);
> +	} else {
> +		pix->width = clamp(pix->width, MIN_WIDTH, MAX_WIDTH);
> +		pix->height = clamp(pix->height, MIN_HEIGHT, MAX_HEIGHT);
> +	}
> +
> +	/* No crop if JPEG is requested */
> +	do_crop = dcmi->do_crop && (pix->pixelformat != V4L2_PIX_FMT_JPEG);
>  
> -	if (dcmi->do_crop && dcmi->num_of_sd_framesizes) {
> +	if (do_crop && dcmi->num_of_sd_framesizes) {
>  		struct dcmi_framesize outer_sd_fsize;
>  		/*
>  		 * If crop is requested and sensor have discrete frame sizes,
> @@ -788,7 +879,7 @@ static int dcmi_try_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f,
>  	sd_fsize.width = pix->width;
>  	sd_fsize.height = pix->height;
>  
> -	if (dcmi->do_crop) {
> +	if (do_crop) {
>  		struct v4l2_rect c = dcmi->crop;
>  		struct v4l2_rect max_rect;
>  
> @@ -843,6 +934,10 @@ static int dcmi_set_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f)
>  	if (ret)
>  		return ret;
>  
> +	/* Disable crop if JPEG is requested */
> +	if (pix->pixelformat == V4L2_PIX_FMT_JPEG)
> +		dcmi->do_crop = false;
> +
>  	/* pix to mbus format */
>  	v4l2_fill_mbus_format(mf, pix,
>  			      sd_format->mbus_code);
> @@ -895,6 +990,8 @@ static int dcmi_enum_fmt_vid_cap(struct file *file, void  *priv,
>  		return -EINVAL;
>  
>  	f->pixelformat = dcmi->sd_formats[f->index]->fourcc;
> +	if (f->pixelformat == V4L2_PIX_FMT_JPEG)
> +		f->flags |= V4L2_FMT_FLAG_COMPRESSED;

Not needed, this is done for you in v4l2-ioctl.c.

Regards,

	Hans

>  	return 0;
>  }
>  
> @@ -1315,6 +1412,10 @@ static int dcmi_set_default_fmt(struct stm32_dcmi *dcmi)
>  		.fourcc = V4L2_PIX_FMT_UYVY,
>  		.mbus_code = MEDIA_BUS_FMT_UYVY8_2X8,
>  		.bpp = 2,
> +	}, {
> +		.fourcc = V4L2_PIX_FMT_JPEG,
> +		.mbus_code = MEDIA_BUS_FMT_JPEG_1X8,
> +		.bpp = 1,
>  	},
>  };
>  
>