drm/msm/dpu: add reset_intf_cfg operation for dpu_hw_ctl

Add a reset_intf_cfg operation for dpu_hw_ctl to reset the
entire CTL path by disabling each component namely layer mixer,
3d-merge and interface blocks.

changes in v3:
	- none
Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/483502/
Link: https://lore.kernel.org/r/1650984096-9964-5-git-send-email-quic_abhinavk@quicinc.comSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

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

@@ -563,6 +563,37 @@ static void dpu_hw_ctl_intf_cfg(struct dpu_hw_ctl *ctx,
 	DPU_REG_WRITE(c, CTL_TOP, intf_cfg);
 }
 
+static void dpu_hw_ctl_reset_intf_cfg_v1(struct dpu_hw_ctl *ctx,
+		struct dpu_hw_intf_cfg *cfg)
+{
+	struct dpu_hw_blk_reg_map *c = &ctx->hw;
+	u32 intf_active = 0;
+	u32 merge3d_active = 0;
+
+	/*
+	 * This API resets each portion of the CTL path namely,
+	 * clearing the sspps staged on the lm, merge_3d block,
+	 * interfaces etc to ensure clean teardown of the pipeline.
+	 * This will be used for writeback to begin with to have a
+	 * proper teardown of the writeback session but upon further
+	 * validation, this can be extended to all interfaces.
+	 */
+	if (cfg->merge_3d) {
+		merge3d_active = DPU_REG_READ(c, CTL_MERGE_3D_ACTIVE);
+		merge3d_active &= ~BIT(cfg->merge_3d - MERGE_3D_0);
+		DPU_REG_WRITE(c, CTL_MERGE_3D_ACTIVE,
+				merge3d_active);
+	}
+
+	dpu_hw_ctl_clear_all_blendstages(ctx);
+
+	if (cfg->intf) {
+		intf_active = DPU_REG_READ(c, CTL_INTF_ACTIVE);
+		intf_active &= ~BIT(cfg->intf - INTF_0);
+		DPU_REG_WRITE(c, CTL_INTF_ACTIVE, intf_active);
+	}
+}
+
 static void dpu_hw_ctl_set_fetch_pipe_active(struct dpu_hw_ctl *ctx,
 	unsigned long *fetch_active)
 {
@@ -586,6 +617,7 @@ static void _setup_ctl_ops(struct dpu_hw_ctl_ops *ops,
 	if (cap & BIT(DPU_CTL_ACTIVE_CFG)) {
 		ops->trigger_flush = dpu_hw_ctl_trigger_flush_v1;
 		ops->setup_intf_cfg = dpu_hw_ctl_intf_cfg_v1;
+		ops->reset_intf_cfg = dpu_hw_ctl_reset_intf_cfg_v1;
 		ops->update_pending_flush_intf =
 			dpu_hw_ctl_update_pending_flush_intf_v1;
 		ops->update_pending_flush_merge_3d =

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

@@ -140,6 +140,14 @@ struct dpu_hw_ctl_ops {
 	void (*setup_intf_cfg)(struct dpu_hw_ctl *ctx,
 		struct dpu_hw_intf_cfg *cfg);
 
+	/**
+	 * reset ctl_path interface config
+	 * @ctx    : ctl path ctx pointer
+	 * @cfg    : interface config structure pointer
+	 */
+	void (*reset_intf_cfg)(struct dpu_hw_ctl *ctx,
+			struct dpu_hw_intf_cfg *cfg);
+
 	int (*reset)(struct dpu_hw_ctl *c);
 
 	/*