Prepare for multiple video streams from the same sensor by adding a use
counter to each subdevice. The counter is increase 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 allow 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.
Signed-off-by: Niklas Söderlund <niklas.soderlund@xxxxxxxxxxxx>
---
drivers/media/platform/vimc/vimc-debayer.c | 8 ++++++++
drivers/media/platform/vimc/vimc-scaler.c | 8 ++++++++
drivers/media/platform/vimc/vimc-sensor.c | 7 +++++++
3 files changed, 23 insertions(+)
diff --git a/drivers/media/platform/vimc/vimc-debayer.c b/drivers/media/platform/vimc/vimc-debayer.c
index 281f9c1a7249ad1d..624fc23ce3077d40 100644
--- a/drivers/media/platform/vimc/vimc-debayer.c
+++ b/drivers/media/platform/vimc/vimc-debayer.c
@@ -56,6 +56,7 @@ struct vimc_deb_device {
struct vimc_ent_device ved;
struct v4l2_subdev sd;
struct device *dev;
+ atomic_t use_count;
/* The active format */
struct v4l2_mbus_framefmt sink_fmt;
u32 src_code;
@@ -337,6 +338,9 @@ static int vimc_deb_s_stream(struct v4l2_subdev *sd, int enable)
const struct v4l2_format_info *pix_info;
unsigned int frame_size;
+ if (atomic_inc_return(&vdeb->use_count) != 1)
+ return 0;
+
if (vdeb->src_frame)
return 0;
@@ -374,6 +378,9 @@ 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;
@@ -562,6 +569,7 @@ static int vimc_deb_comp_bind(struct device *comp, struct device *master,
vdeb->ved.process_frame = vimc_deb_process_frame;
dev_set_drvdata(comp, &vdeb->ved);
vdeb->dev = comp;
+ atomic_set(&vdeb->use_count, 0);
/* Initialize the frame format */
vdeb->sink_fmt = sink_fmt_default;
diff --git a/drivers/media/platform/vimc/vimc-scaler.c b/drivers/media/platform/vimc/vimc-scaler.c
index 8aecf8e920310608..37d2020d987a7d80 100644
--- a/drivers/media/platform/vimc/vimc-scaler.c
+++ b/drivers/media/platform/vimc/vimc-scaler.c
@@ -45,6 +45,7 @@ struct vimc_sca_device {
struct vimc_ent_device ved;
struct v4l2_subdev sd;
struct device *dev;
+ atomic_t use_count;
/* NOTE: the source fmt is the same as the sink
* with the width and hight multiplied by mult
*/
@@ -213,6 +214,9 @@ static int vimc_sca_s_stream(struct v4l2_subdev *sd, int enable)
const struct v4l2_format_info *pix_info;
unsigned int frame_size;
+ if (atomic_inc_return(&vsca->use_count) != 1)
+ return 0;
+
if (vsca->src_frame)
return 0;
@@ -242,6 +246,9 @@ 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;
@@ -396,6 +403,7 @@ static int vimc_sca_comp_bind(struct device *comp, struct device *master,
vsca->ved.process_frame = vimc_sca_process_frame;
dev_set_drvdata(comp, &vsca->ved);
vsca->dev = comp;
+ atomic_set(&vsca->use_count, 0);
/* Initialize the frame format */
vsca->sink_fmt = sink_fmt_default;
diff --git a/drivers/media/platform/vimc/vimc-sensor.c b/drivers/media/platform/vimc/vimc-sensor.c
index baca9ca67ce0af0b..36c3cea85a185f4b 100644
--- a/drivers/media/platform/vimc/vimc-sensor.c
+++ b/drivers/media/platform/vimc/vimc-sensor.c
@@ -34,6 +34,7 @@ struct vimc_sen_device {
struct vimc_ent_device ved;
struct v4l2_subdev sd;
struct device *dev;
+ atomic_t use_count;
struct tpg_data tpg;
struct task_struct *kthread_sen;
u8 *frame;
@@ -197,6 +198,9 @@ static int vimc_sen_s_stream(struct v4l2_subdev *sd, int enable)
const struct v4l2_format_info *pix_info;
unsigned int frame_size;
+ if (atomic_inc_return(&vsen->use_count) != 1)
+ return 0;
+
if (vsen->kthread_sen)
/* tpg is already executing */
return 0;
@@ -218,6 +222,8 @@ static int vimc_sen_s_stream(struct v4l2_subdev *sd, int enable)
vimc_sen_tpg_s_format(vsen);
} else {
+ if (atomic_dec_return(&vsen->use_count) != 0)
+ return 0;
vfree(vsen->frame);
vsen->frame = NULL;
@@ -367,6 +373,7 @@ static int vimc_sen_comp_bind(struct device *comp, struct device *master,
vsen->ved.process_frame = vimc_sen_process_frame;
dev_set_drvdata(comp, &vsen->ved);
vsen->dev = comp;
+ atomic_set(&vsen->use_count, 0);
/* Initialize the frame format */
vsen->mbus_format = fmt_default;
--
2.21.0
