disp: msm: sde: expose early-wb-fence option for 2-pass composition

Add a writeback connector property EARLY-FENCE-LINE to give usermode
the control on when to trigger the retire fence. This option is useful
in 2-pass composition, where the writeback triggers the retire-fence
early based on the prog-line which allows primary to start the fetch
before wb transaction is fully completed. This helps to keep the clks
and bw low. WB hardware generates the line-ptr-irq when wb output reaches
the configured prog-line. Retire fence is triggered based on the irq by
default and wb-done handles for cases where line-ptr-irq is missed.

Change-Id: I20867979693dc3447f77da24cd7e88305947fb6d
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>

msm/sde/sde_wb.c

@@ -564,6 +564,10 @@ int sde_wb_connector_post_init(struct drm_connector *connector, void *display)
 			ARRAY_SIZE(e_fb_translation_mode), 0,
 			CONNECTOR_PROP_FB_TRANSLATION_MODE);
 
+	if (wb_dev->wb_cfg->features & BIT(SDE_WB_PROG_LINE))
+		msm_property_install_range(&c_conn->property_info, "early_fence_line",
+			0x0, 0, UINT_MAX, 0, CONNECTOR_PROP_EARLY_FENCE_LINE);
+
 	sde_wb_connector_install_dither_property(wb_dev, c_conn);
 
 	return 0;