MIPI-CSI has internal memory mapped buffers for the frame embedded
(non-image) data. There are two buffers, for even and odd frames which
need to be saved after an interrupt is raised. The packet data buffers
size is 4 KiB and there is no status register in the hardware where the
actual non-image data size can be read from. Hence the driver copies
whole packet data buffer into a buffer provided by the FIMC driver.
This will form a separate plane in the user buffer.
When FIMC DMA engine is stopped by the driver due the to user space
not keeping up with buffer de-queuing the MIPI-CSIS will still run,
however it must discard data which is not captured by FIMC. Which
frames are actually captured by MIPI-CSIS is determined by means of
the s_rx_buffer subdev callback. When it is not called after a single
embedded data frame has been captured and copied and before next
embedded data frame interrupt occurrs, subsequent embedded data frames
will be dropped.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
drivers/media/platform/s5p-fimc/mipi-csis.c | 51 +++++++++++++++++++++++++++++
1 file changed, 51 insertions(+)
diff --git a/drivers/media/platform/s5p-fimc/mipi-csis.c b/drivers/media/platform/s5p-fimc/mipi-csis.c
index c1c5c86..306410f 100644
--- a/drivers/media/platform/s5p-fimc/mipi-csis.c
+++ b/drivers/media/platform/s5p-fimc/mipi-csis.c
@@ -98,6 +98,11 @@ MODULE_PARM_DESC(debug, "Debug level (0-2)");
#define CSIS_MAX_PIX_WIDTH 0xffff
#define CSIS_MAX_PIX_HEIGHT 0xffff
+/* Non-image packet data buffers */
+#define S5PCSIS_PKTDATA_ODD 0x2000
+#define S5PCSIS_PKTDATA_EVEN 0x3000
+#define S5PCSIS_PKTDATA_SIZE SZ_4K
+
enum {
CSIS_CLK_MUX,
CSIS_CLK_GATE,
@@ -144,6 +149,11 @@ static const struct s5pcsis_event s5pcsis_events[] = {
};
#define S5PCSIS_NUM_EVENTS ARRAY_SIZE(s5pcsis_events)
+struct csis_pktbuf {
+ u32 *data;
+ unsigned int len;
+};
+
/**
* struct csis_state - the driver's internal state data structure
* @lock: mutex serializing the subdev and power management operations,
@@ -160,6 +170,7 @@ static const struct s5pcsis_event s5pcsis_events[] = {
* @csis_fmt: current CSIS pixel format
* @format: common media bus format for the source and sink pad
* @slock: spinlock protecting structure members below
+ * @pkt_buf: the frame embedded (non-image) data buffer
* @events: MIPI-CSIS event (error) counters
*/
struct csis_state {
@@ -177,6 +188,7 @@ struct csis_state {
struct v4l2_mbus_framefmt format;
struct spinlock slock;
+ struct csis_pktbuf pkt_buf;
struct s5pcsis_event events[S5PCSIS_NUM_EVENTS];
};
@@ -534,6 +546,21 @@ static int s5pcsis_get_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
return 0;
}
+static int s5pcsis_s_rx_buffer(struct v4l2_subdev *sd, void *buf,
+ unsigned int *size)
+{
+ struct csis_state *state = sd_to_csis_state(sd);
+ unsigned long flags;
+
+ spin_lock_irqsave(&state->slock, flags);
+ *size = min_t(unsigned int, *size, S5PCSIS_PKTDATA_SIZE);
+ state->pkt_buf.data = buf;
+ state->pkt_buf.len = *size;
+ spin_unlock_irqrestore(&state->slock, flags);
+
+ return 0;
+}
+
static int s5pcsis_log_status(struct v4l2_subdev *sd)
{
struct csis_state *state = sd_to_csis_state(sd);
@@ -571,6 +598,7 @@ static struct v4l2_subdev_pad_ops s5pcsis_pad_ops = {
};
static struct v4l2_subdev_video_ops s5pcsis_video_ops = {
+ .s_rx_buffer = s5pcsis_s_rx_buffer,
.s_stream = s5pcsis_s_stream,
};
@@ -580,16 +608,39 @@ static struct v4l2_subdev_ops s5pcsis_subdev_ops = {
.video = &s5pcsis_video_ops,
};
+static void s5pcsis_pkt_copy(struct csis_state *state, u32 *buf,
+ u32 offset, u32 size)
+{
+ int i;
+
+ for (i = 0; i < S5PCSIS_PKTDATA_SIZE; i += 4, buf++)
+ *buf = s5pcsis_read(state, offset + i);
+}
+
static irqreturn_t s5pcsis_irq_handler(int irq, void *dev_id)
{
struct csis_state *state = dev_id;
+ struct csis_pktbuf *pktbuf = &state->pkt_buf;
unsigned long flags;
u32 status;
status = s5pcsis_read(state, S5PCSIS_INTSRC);
+ s5pcsis_write(state, S5PCSIS_INTSRC, status);
spin_lock_irqsave(&state->slock, flags);
+ if ((status & S5PCSIS_INTSRC_NON_IMAGE_DATA) && pktbuf->data) {
+ u32 offset;
+
+ if (status & S5PCSIS_INTSRC_EVEN)
+ offset = S5PCSIS_PKTDATA_EVEN;
+ else
+ offset = S5PCSIS_PKTDATA_ODD;
+
+ s5pcsis_pkt_copy(state, pktbuf->data, offset, pktbuf->len);
+ pktbuf->data = NULL;
+ }
+
/* Update the event/error counters */
if ((status & S5PCSIS_INTSRC_ERRORS) || debug) {
int i;
--
1.7.11.3
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