From: Vedang Nagar <quic_vnagar@quicinc.com>

Based on state machine design, add allow checks to transition from one
sub-state to another sub-states.

Signed-off-by: Vedang Nagar <quic_vnagar@quicinc.com>
Signed-off-by: Dikshita Agarwal <quic_dikshita@quicinc.com>
---
 .../platform/qcom/iris/iris_hfi_gen1_command.c     | 12 ++++++-
 drivers/media/platform/qcom/iris/iris_state.c      | 40 ++++++++++++++++++++++
 drivers/media/platform/qcom/iris/iris_state.h      |  3 ++
 3 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/qcom/iris/iris_hfi_gen1_command.c b/drivers/media/platform/qcom/iris/iris_hfi_gen1_command.c
index e1fbbb3c196d..64f887d9a17d 100644
--- a/drivers/media/platform/qcom/iris/iris_hfi_gen1_command.c
+++ b/drivers/media/platform/qcom/iris/iris_hfi_gen1_command.c
@@ -135,6 +135,9 @@ static int iris_hfi_gen1_session_start(struct iris_inst *inst, u32 plane)
 	if (!V4L2_TYPE_IS_OUTPUT(plane))
 		return 0;
 
+	if (inst->sub_state & IRIS_INST_SUB_LOAD_RESOURCES)
+		return 0;
+
 	reinit_completion(&inst->completion);
 	iris_hfi_gen1_packet_session_cmd(inst, &packet, HFI_CMD_SESSION_LOAD_RESOURCES);
 
@@ -153,7 +156,11 @@ static int iris_hfi_gen1_session_start(struct iris_inst *inst, u32 plane)
 	if (ret)
 		return ret;
 
-	return iris_wait_for_session_response(inst, false);
+	ret = iris_wait_for_session_response(inst, false);
+	if (ret)
+		return ret;
+
+	return iris_inst_change_sub_state(inst, 0, IRIS_INST_SUB_LOAD_RESOURCES);
 }
 
 static int iris_hfi_gen1_session_stop(struct iris_inst *inst, u32 plane)
@@ -180,6 +187,9 @@ static int iris_hfi_gen1_session_stop(struct iris_inst *inst, u32 plane)
 		ret = iris_hfi_queue_cmd_write(core, &pkt, pkt.shdr.hdr.size);
 		if (!ret)
 			ret = iris_wait_for_session_response(inst, false);
+
+		iris_inst_change_sub_state(inst, IRIS_INST_SUB_LOAD_RESOURCES, 0);
+
 		iris_helper_buffers_done(inst, V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE,
 					 VB2_BUF_STATE_ERROR);
 		iris_helper_buffers_done(inst, V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE,
diff --git a/drivers/media/platform/qcom/iris/iris_state.c b/drivers/media/platform/qcom/iris/iris_state.c
index f12306e735ec..5976e926c83d 100644
--- a/drivers/media/platform/qcom/iris/iris_state.c
+++ b/drivers/media/platform/qcom/iris/iris_state.c
@@ -105,6 +105,43 @@ int iris_inst_state_change_streamoff(struct iris_inst *inst, u32 plane)
 	return iris_inst_change_state(inst, new_state);
 }
 
+static bool iris_inst_allow_sub_state(struct iris_inst *inst, enum iris_inst_sub_state sub_state)
+{
+	if (!sub_state)
+		return true;
+
+	switch (inst->state) {
+	case IRIS_INST_INIT:
+		if (sub_state & IRIS_INST_SUB_LOAD_RESOURCES)
+			return true;
+		return false;
+	case IRIS_INST_INPUT_STREAMING:
+		if (sub_state & (IRIS_INST_SUB_FIRST_IPSC | IRIS_INST_SUB_DRC |
+			IRIS_INST_SUB_DRAIN | IRIS_INST_SUB_INPUT_PAUSE))
+			return true;
+		return false;
+	case IRIS_INST_OUTPUT_STREAMING:
+		if (sub_state & (IRIS_INST_SUB_DRC_LAST |
+			IRIS_INST_SUB_DRAIN_LAST | IRIS_INST_SUB_OUTPUT_PAUSE))
+			return true;
+		return false;
+	case IRIS_INST_STREAMING:
+		if (sub_state & (IRIS_INST_SUB_DRC | IRIS_INST_SUB_DRAIN |
+			IRIS_INST_SUB_DRC_LAST | IRIS_INST_SUB_DRAIN_LAST |
+			IRIS_INST_SUB_INPUT_PAUSE | IRIS_INST_SUB_OUTPUT_PAUSE))
+			return true;
+		return false;
+	case IRIS_INST_DEINIT:
+		if (sub_state & (IRIS_INST_SUB_DRC | IRIS_INST_SUB_DRAIN |
+			IRIS_INST_SUB_DRC_LAST | IRIS_INST_SUB_DRAIN_LAST |
+			IRIS_INST_SUB_INPUT_PAUSE | IRIS_INST_SUB_OUTPUT_PAUSE))
+			return true;
+		return false;
+	default:
+		return false;
+	}
+}
+
 int iris_inst_change_sub_state(struct iris_inst *inst,
 			       enum iris_inst_sub_state clear_sub_state,
 			       enum iris_inst_sub_state set_sub_state)
@@ -124,6 +161,9 @@ int iris_inst_change_sub_state(struct iris_inst *inst,
 
 	prev_sub_state = inst->sub_state;
 
+	if (!iris_inst_allow_sub_state(inst, set_sub_state))
+		return -EINVAL;
+
 	inst->sub_state |= set_sub_state;
 	inst->sub_state &= ~clear_sub_state;
 
diff --git a/drivers/media/platform/qcom/iris/iris_state.h b/drivers/media/platform/qcom/iris/iris_state.h
index bf645f6f879c..4bb37423ed05 100644
--- a/drivers/media/platform/qcom/iris/iris_state.h
+++ b/drivers/media/platform/qcom/iris/iris_state.h
@@ -113,6 +113,8 @@ enum iris_inst_state {
  * IRIS_INST_SUB_OUTPUT_PAUSE: last buffer is received form firmware as part
  *                             of drc sequence. This indicates that
  *                             firmware is paused to process any further output frames.
+ * IRIS_INST_SUB_LOAD_RESOURCES: indicates all the resources have been loaded by the
+ *                               firmware and it is ready for processing.
  */
 enum iris_inst_sub_state {
 	IRIS_INST_SUB_FIRST_IPSC	= BIT(0),
@@ -122,6 +124,7 @@ enum iris_inst_sub_state {
 	IRIS_INST_SUB_DRAIN_LAST	= BIT(4),
 	IRIS_INST_SUB_INPUT_PAUSE	= BIT(5),
 	IRIS_INST_SUB_OUTPUT_PAUSE	= BIT(6),
+	IRIS_INST_SUB_LOAD_RESOURCES	= BIT(7),
 };
 
 int iris_inst_change_state(struct iris_inst *inst,

-- 
2.34.1