Prepare for multiple video streams from the same sensor by adding a use
counter to each subdevice. The counter is increased for every s_stream(1)
and decremented for every s_stream(0) call.
The subdevice stream is not started or stopped unless the usage count go
from 0 to 1 (started) or from 1 to 0 (stopped). This allows for multiple
s_stream() calls to try to either start or stop the device while only
the first/last call will actually effect the state of the device.
[Kaaira: rebased the patch on current HEAD of media-tree
(8f2a4a9d5ff5202d0b3e3a144ebb9b67aabadd29)]
Signed-off-by: Niklas Söderlund <niklas.soderlund@xxxxxxxxxxxx>
Signed-off-by: Kaaira Gupta <kgupta@xxxxxxxxxxxxx>
---
drivers/media/test-drivers/vimc/vimc-debayer.c | 8 ++++++++
drivers/media/test-drivers/vimc/vimc-scaler.c | 8 ++++++++
drivers/media/test-drivers/vimc/vimc-sensor.c | 9 ++++++++-
3 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/drivers/media/test-drivers/vimc/vimc-debayer.c b/drivers/media/test-drivers/vimc/vimc-debayer.c
index c3f6fef34f68..93fe19d8d2b4 100644
--- a/drivers/media/test-drivers/vimc/vimc-debayer.c
+++ b/drivers/media/test-drivers/vimc/vimc-debayer.c
@@ -29,6 +29,7 @@ struct vimc_deb_pix_map {
struct vimc_deb_device {
struct vimc_ent_device ved;
struct v4l2_subdev sd;
+ atomic_t use_count;
/* The active format */
struct v4l2_mbus_framefmt sink_fmt;
u32 src_code;
@@ -343,6 +344,9 @@ static int vimc_deb_s_stream(struct v4l2_subdev *sd, int enable)
const struct vimc_pix_map *vpix;
unsigned int frame_size;
+ if (atomic_inc_return(&vdeb->use_count) != 1)
+ return 0;
+
if (vdeb->src_frame)
return 0;
@@ -368,6 +372,9 @@ static int vimc_deb_s_stream(struct v4l2_subdev *sd, int enable)
return -ENOMEM;
} else {
+ if (atomic_dec_return(&vdeb->use_count) != 0)
+ return 0;
+
if (!vdeb->src_frame)
return 0;
@@ -595,6 +602,7 @@ static struct vimc_ent_device *vimc_deb_add(struct vimc_device *vimc,
vdeb->ved.process_frame = vimc_deb_process_frame;
vdeb->ved.dev = vimc->mdev.dev;
vdeb->mean_win_size = vimc_deb_ctrl_mean_win_size.def;
+ atomic_set(&vdeb->use_count, 0);
/* Initialize the frame format */
vdeb->sink_fmt = sink_fmt_default;
diff --git a/drivers/media/test-drivers/vimc/vimc-scaler.c b/drivers/media/test-drivers/vimc/vimc-scaler.c
index 121fa7d62a2e..9b8458dbe57c 100644
--- a/drivers/media/test-drivers/vimc/vimc-scaler.c
+++ b/drivers/media/test-drivers/vimc/vimc-scaler.c
@@ -25,6 +25,7 @@ MODULE_PARM_DESC(sca_mult, " the image size multiplier");
struct vimc_sca_device {
struct vimc_ent_device ved;
struct v4l2_subdev sd;
+ atomic_t use_count;
/* NOTE: the source fmt is the same as the sink
* with the width and hight multiplied by mult
*/
@@ -340,6 +341,9 @@ static int vimc_sca_s_stream(struct v4l2_subdev *sd, int enable)
const struct vimc_pix_map *vpix;
unsigned int frame_size;
+ if (atomic_inc_return(&vsca->use_count) != 1)
+ return 0;
+
if (vsca->src_frame)
return 0;
@@ -363,6 +367,9 @@ static int vimc_sca_s_stream(struct v4l2_subdev *sd, int enable)
return -ENOMEM;
} else {
+ if (atomic_dec_return(&vsca->use_count) != 0)
+ return 0;
+
if (!vsca->src_frame)
return 0;
@@ -506,6 +513,7 @@ static struct vimc_ent_device *vimc_sca_add(struct vimc_device *vimc,
vsca->ved.process_frame = vimc_sca_process_frame;
vsca->ved.dev = vimc->mdev.dev;
+ atomic_set(&vsca->use_count, 0);
/* Initialize the frame format */
vsca->sink_fmt = sink_fmt_default;
diff --git a/drivers/media/test-drivers/vimc/vimc-sensor.c b/drivers/media/test-drivers/vimc/vimc-sensor.c
index ba5db5a150b4..dbe169604e71 100644
--- a/drivers/media/test-drivers/vimc/vimc-sensor.c
+++ b/drivers/media/test-drivers/vimc/vimc-sensor.c
@@ -24,6 +24,7 @@ struct vimc_sen_device {
struct vimc_ent_device ved;
struct v4l2_subdev sd;
struct tpg_data tpg;
+ atomic_t use_count;
u8 *frame;
enum vimc_sen_osd_mode osd_value;
u64 start_stream_ts;
@@ -250,8 +251,10 @@ static int vimc_sen_s_stream(struct v4l2_subdev *sd, int enable)
const struct vimc_pix_map *vpix;
unsigned int frame_size;
- vsen->start_stream_ts = ktime_get_ns();
+ if (atomic_inc_return(&vsen->use_count) != 1)
+ return 0;
+ vsen->start_stream_ts = ktime_get_ns();
/* Calculate the frame size */
vpix = vimc_pix_map_by_code(vsen->mbus_format.code);
frame_size = vsen->mbus_format.width * vpix->bpp *
@@ -270,6 +273,9 @@ static int vimc_sen_s_stream(struct v4l2_subdev *sd, int enable)
} else {
+ if (atomic_dec_return(&vsen->use_count) != 0)
+ return 0;
+
vfree(vsen->frame);
vsen->frame = NULL;
}
@@ -430,6 +436,7 @@ static struct vimc_ent_device *vimc_sen_add(struct vimc_device *vimc,
vsen->ved.process_frame = vimc_sen_process_frame;
vsen->ved.dev = vimc->mdev.dev;
+ atomic_set(&vsen->use_count, 0);
/* Initialize the frame format */
vsen->mbus_format = fmt_default;
--
2.17.1
