mdss: mdp: parse memory handle for cont splash buffer

Continuous splash screen buffer is reserved in
target dtsi file for MSM8994 target. FB driver should
parse this memory handle using "linux,continuous-region"
to get the splash screen buffer address and size. This
avoids usage of "qcom,memory-reserve" entry which forces
user to provide duplicate information.

Change-Id: Ice6cddf6c71a2de9adf15a763434a310e07a3da6
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>

Documentation/devicetree/bindings/fb/mdss-mdp.txt

@@ -424,11 +424,18 @@ Subnode properties:
 			 for the framebuffer used to display the splash screen.
 			 This property is required whenever the continuous splash
 			 screen feature is enabled for the corresponding
-			 framebuffer device.
+			 framebuffer device. It should be used for only 32bit
+			 kernel.
+- qcom,cont-splash-memory: Specifies the memory block region reserved for
+			 continuous splash screen feature. This property should be
+			 defined for corresponding framebuffer device if
+			 "qcom,memblock-reserve" is not defined when continuous
+			 splash screen feature is enabled.
 - linux,contiguous-region: Phandle to the continuous memory region reserved for
-			 frame-buffer. Size of this region is dependent on the
-			 display panel resolution and buffering scheme.
-			 Currently driver uses double buffering.
+			 frame-buffer or continuous splash screen. Size of this
+			 region is dependent on the display panel resolution and
+			 buffering scheme for frame-buffer node. Currently driver
+			 uses double buffering.
 
 			 Example: Width = 1920, Height = 1080, BytesPerPixel = 4,
 			 Number of frame-buffers reserved = 2.
@@ -578,6 +585,9 @@ Example:
 			qcom,mdss-fb-split = <480 240>
 			linux,contiguous-region = <&fb_mem>;
 			qcom,mdss-fb-splash-logo-enabled:
+			qcom,cont-splash-memory {
+				linux,contiguous-region = <&cont_splash_mem>;
+			};
 		};
 	};
 

drivers/video/fbdev/msm/mdss_mdp_splash_logo.c

@@ -19,6 +19,7 @@
 #include <linux/memblock.h>
 #include <linux/bootmem.h>
 #include <linux/iommu.h>
+#include <linux/of_address.h>
 #include <linux/fb.h>
 #include <linux/dma-buf.h>
 
@@ -591,25 +592,51 @@ static __ref int mdss_mdp_splash_parse_dt(struct msm_fb_data_type *mfd)
 	struct mdss_overlay_private *mdp5_mdata = mfd_to_mdp5_data(mfd);
 	int len = 0, rc = 0;
 	u32 offsets[2];
+	struct device_node *pnode, *child_node;
 
 	mfd->splash_info.splash_logo_enabled =
 				of_property_read_bool(pdev->dev.of_node,
 				"qcom,mdss-fb-splash-logo-enabled");
 
 	of_find_property(pdev->dev.of_node, "qcom,memblock-reserve", &len);
-	if (len < 1) {
-		pr_debug("mem reservation for splash screen fb not present\n");
-		rc = -EINVAL;
-		goto error;
-	}
+	if (len) {
+		len = len / sizeof(u32);
 
-	len = len / sizeof(u32);
-
-	rc = of_property_read_u32_array(pdev->dev.of_node,
+		rc = of_property_read_u32_array(pdev->dev.of_node,
 			"qcom,memblock-reserve", offsets, len);
-	if (rc) {
-		pr_debug("error reading mem reserve settings for fb\n");
-		goto error;
+		if (rc) {
+			pr_err("error reading mem reserve settings for fb\n");
+			goto error;
+		}
+	} else {
+		child_node = of_get_child_by_name(pdev->dev.of_node,
+					"qcom,cont-splash-memory");
+		if (!child_node) {
+			pr_err("splash mem child node is not present\n");
+			rc = -EINVAL;
+			goto error;
+		}
+
+		pnode = of_parse_phandle(child_node, "linux,contiguous-region",
+					0);
+		if (pnode != NULL) {
+			const u32 *addr;
+			u64 size;
+			addr = of_get_address(pnode, 0, &size, NULL);
+			if (!addr) {
+				pr_err("failed to parse the splash memory address\n");
+				of_node_put(pnode);
+				rc = -EINVAL;
+				goto error;
+			}
+			offsets[0] = (u32) of_read_ulong(addr, 2);
+			offsets[1] = (u32) size;
+			of_node_put(pnode);
+		} else {
+			pr_err("mem reservation for splash screen fb not present\n");
+			rc = -EINVAL;
+			goto error;
+		}
 	}
 
 	if (!memblock_is_reserved(offsets[0])) {