drm/msm/dpu: Add a function to retrieve the current CTL status

Add a function that returns whether the requested CTL is active or not:
this will be used in a later commit to fix command mode panel issues.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Link: https://lore.kernel.org/r/20210911163919.47173-1-angelogioacchino.delregno@somainline.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c

@@ -92,6 +92,11 @@ static inline void dpu_hw_ctl_trigger_start(struct dpu_hw_ctl *ctx)
 	DPU_REG_WRITE(&ctx->hw, CTL_START, 0x1);
 }
 
+static inline bool dpu_hw_ctl_is_started(struct dpu_hw_ctl *ctx)
+{
+	return !!(DPU_REG_READ(&ctx->hw, CTL_START) & BIT(0));
+}
+
 static inline void dpu_hw_ctl_trigger_pending(struct dpu_hw_ctl *ctx)
 {
 	trace_dpu_hw_ctl_trigger_prepare(ctx->pending_flush_mask,
@@ -587,6 +592,7 @@ static void _setup_ctl_ops(struct dpu_hw_ctl_ops *ops,
 	ops->get_pending_flush = dpu_hw_ctl_get_pending_flush;
 	ops->get_flush_register = dpu_hw_ctl_get_flush_register;
 	ops->trigger_start = dpu_hw_ctl_trigger_start;
+	ops->is_started = dpu_hw_ctl_is_started;
 	ops->trigger_pending = dpu_hw_ctl_trigger_pending;
 	ops->reset = dpu_hw_ctl_reset_control;
 	ops->wait_reset_status = dpu_hw_ctl_wait_reset_status;

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h

@@ -61,6 +61,13 @@ struct dpu_hw_ctl_ops {
 	 */
 	void (*trigger_start)(struct dpu_hw_ctl *ctx);
 
+	/**
+	 * check if the ctl is started
+	 * @ctx       : ctl path ctx pointer
+	 * @Return: true if started, false if stopped
+	 */
+	bool (*is_started)(struct dpu_hw_ctl *ctx);
+
 	/**
 	 * kickoff prepare is in progress hw operation for sw
 	 * controlled interfaces: DSI cmd mode and WB interface