[PATCH v2] media: stm32-dcmi: add JPEG support

From: Hugues Fruchet
Date: Wed Feb 28 2018 - 12:20:56 EST


Add DCMI JPEG support.

Signed-off-by: Hugues Fruchet <hugues.fruchet@xxxxxx>
---
version 2:
- Removed V4L2_FMT_FLAG_COMPRESSED flag setting already set by V4L2 core
See https://www.mail-archive.com/linux-media@xxxxxxxxxxxxxxx/msg126825.html

drivers/media/platform/stm32/stm32-dcmi.c | 193 ++++++++++++++++++++++--------
1 file changed, 146 insertions(+), 47 deletions(-)

diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
index 269e963..36f9a77 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);
@@ -1315,6 +1410,10 @@ 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,
},
};

--
1.9.1