sunxi: setup simplefb for Allwinner DE2

As the support of EFI boot on Allwinner H3 is broken, we still need to
use simplefb to pass the framebuffer to Linux.

Add code to setup simplefb for Allwinner DE2 driver.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>

drivers/video/sunxi/sunxi_de2.c

@@ -10,6 +10,8 @@
 #include <display.h>
 #include <dm.h>
 #include <edid.h>
+#include <fdtdec.h>
+#include <fdt_support.h>
 #include <video.h>
 #include <asm/global_data.h>
 #include <asm/io.h>
@@ -256,3 +258,82 @@ U_BOOT_DRIVER(sunxi_de2) = {
 U_BOOT_DEVICE(sunxi_de2) = {
 	.name = "sunxi_de2"
 };
+
+/*
+ * Simplefb support.
+ */
+#if defined(CONFIG_OF_BOARD_SETUP) && defined(CONFIG_VIDEO_DT_SIMPLEFB)
+int sunxi_simplefb_setup(void *blob)
+{
+	struct udevice *de2, *hdmi;
+	struct video_priv *de2_priv;
+	struct video_uc_platdata *de2_plat;
+	int mux;
+	int offset, ret;
+	u64 start, size;
+	const char *pipeline = NULL;
+
+	debug("Setting up simplefb\n");
+
+	if (IS_ENABLED(CONFIG_MACH_SUNXI_H3_H5))
+		mux = 0;
+	else
+		mux = 1;
+
+	/* Skip simplefb setting if DE2 / HDMI is not present */
+	ret = uclass_find_device_by_name(UCLASS_VIDEO,
+					 "sunxi_de2", &de2);
+	if (ret) {
+		debug("DE2 not present\n");
+		return 0;
+	}
+
+	ret = uclass_find_device_by_name(UCLASS_DISPLAY,
+					 "sunxi_dw_hdmi", &hdmi);
+	if (ret) {
+		debug("HDMI not present\n");
+		return 0;
+	}
+
+	if(mux == 0)
+		pipeline = "mixer0-lcd0-hdmi";
+	else
+		pipeline = "mixer1-lcd1-hdmi";
+
+	de2_priv = dev_get_uclass_priv(de2);
+	de2_plat = dev_get_uclass_platdata(de2);
+
+	/* Find a prefilled simpefb node, matching out pipeline config */
+	offset = fdt_node_offset_by_compatible(blob, -1,
+					       "allwinner,simple-framebuffer");
+	while (offset >= 0) {
+		ret = fdt_stringlist_search(blob, offset, "allwinner,pipeline",
+					    pipeline);
+		if (ret == 0)
+			break;
+		offset = fdt_node_offset_by_compatible(blob, offset,
+					       "allwinner,simple-framebuffer");
+	}
+	if (offset < 0) {
+		eprintf("Cannot setup simplefb: node not found\n");
+		return 0; /* Keep older kernels working */
+	}
+
+	start = gd->bd->bi_dram[0].start;
+	size = de2_plat->base - start;
+	ret = fdt_fixup_memory_banks(blob, &start, &size, 1);
+	if (ret) {
+		eprintf("Cannot setup simplefb: Error reserving memory\n");
+		return ret;
+	}
+
+	ret = fdt_setup_simplefb_node(blob, offset, de2_plat->base,
+			de2_priv->xsize, de2_priv->ysize,
+			(1 << de2_priv->bpix) / 8 * de2_priv->xsize,
+			"x8r8g8b8");
+	if (ret)
+		eprintf("Cannot setup simplefb: Error setting properties\n");
+
+	return ret;
+}
+#endif /* CONFIG_OF_BOARD_SETUP && CONFIG_VIDEO_DT_SIMPLEFB */

include/configs/sunxi-common.h

@@ -286,6 +286,10 @@ extern int soft_i2c_gpio_scl;
 
 #endif /* CONFIG_VIDEO */
 
+#ifdef CONFIG_VIDEO_DE2
+#define CONFIG_VIDEO_DT_SIMPLEFB
+#endif
+
 /* Ethernet support */
 #ifdef CONFIG_SUNXI_EMAC
 #define CONFIG_PHY_ADDR		1