Expose LCDIF as simple-framebuffer to pass to OSes

I didn't author this patch, just committing it. See below.

Co-authored-by: Patrick Wildt <patrick@blueri.se>

board/boundary/nitrogen8m_som/lcdif.c

@@ -862,10 +862,11 @@ backlighton(void)
 	gpio_direction_output(IMX_GPIO_NR(1, 10), 1);
 }
 
+struct graphic_device imx_lcdif;
+
 void*
 video_hw_init(void)
 {
-	static struct graphic_device lcdif;
 	struct dsi_cfg dsi_cfg;
 	struct video_mode mode;
 	char *err;
@@ -944,25 +945,25 @@ video_hw_init(void)
 		goto out;
 
 	/* fill in Graphic device struct */
-	sprintf(lcdif.modeIdent, "%dx%dx%d", mode.hactive, mode.vactive, 24);
-	lcdif.winSizeX = mode.hactive;
-	lcdif.winSizeY = mode.vactive;
-	lcdif.plnSizeX = mode.hactive;
-	lcdif.plnSizeY = mode.vactive;
-	lcdif.gdfBytesPP = 4;
-	lcdif.gdfIndex = GDF_32BIT_X888RGB;
-	lcdif.memSize = lcdif.plnSizeX * lcdif.plnSizeY * lcdif.gdfBytesPP;
+	sprintf(imx_lcdif.modeIdent, "%dx%dx%d", mode.hactive, mode.vactive, 24);
+	imx_lcdif.winSizeX = mode.hactive;
+	imx_lcdif.winSizeY = mode.vactive;
+	imx_lcdif.plnSizeX = mode.hactive;
+	imx_lcdif.plnSizeY = mode.vactive;
+	imx_lcdif.gdfBytesPP = 4;
+	imx_lcdif.gdfIndex = GDF_32BIT_X888RGB;
+	imx_lcdif.memSize = imx_lcdif.plnSizeX * imx_lcdif.plnSizeY * imx_lcdif.gdfBytesPP;
 
 	fb = (void*)gd->fb_base;
 	if(fb == NULL) {
-		fb = memalign(0x10000, roundup(lcdif.memSize, 0x10000));
+		fb = memalign(0x10000, roundup(imx_lcdif.memSize, 0x10000));
 		if(fb == NULL){
 			err = "no memory for framebuffer";
 			goto out;
 		}
 		gd->fb_base = (uintptr_t)fb;
 	}
-	lcdif.frameAdrs = (uintptr_t)fb;
+	imx_lcdif.frameAdrs = (uintptr_t)fb;
 
 	/* start the pixel clock: SYSTEM_PLL1_CLK, 114Mz */
 	clock_set_target_val(LCDIF_PIXEL_CLK_ROOT, CLK_ROOT_ON | CLK_ROOT_SOURCE_SEL(4) | CLK_ROOT_PRE_DIV(CLK_ROOT_PRE_DIV7));
@@ -978,7 +979,7 @@ video_hw_init(void)
 	/* send the pixels */
 	lcdifinit(&mode, (u32)(unsigned long long)fb);
 
-	return &lcdif;
+	return &imx_lcdif;
 
 out:
 	printf("lcdif: video_hw_init(): %s\n", err);

board/boundary/nitrogen8m_som/nitrogen8m_som.c

@@ -150,8 +150,40 @@ int dram_init(void)
 }
 
 #ifdef CONFIG_OF_BOARD_SETUP
+extern struct graphic_device imx_lcdif;
+
+int lcd_dt_simplefb_add_node(void *blob)
+{
+	static const char compat[] = "simple-framebuffer";
+	static const char disabled[] = "disabled";
+	int off, ret;
+
+	off = fdt_add_subnode(blob, 0, "framebuffer");
+	if (off < 0)
+		return -1;
+
+	ret = fdt_setprop(blob, off, "status", disabled, sizeof(disabled));
+	if (ret < 0)
+		return -1;
+
+	ret = fdt_setprop(blob, off, "compatible", compat, sizeof(compat));
+	if (ret < 0)
+		return -1;
+
+	return fdt_setup_simplefb_node(blob, off, gd->fb_base, imx_lcdif.winSizeX,
+	    imx_lcdif.winSizeY, imx_lcdif.winSizeX * imx_lcdif.gdfBytesPP,
+	    "x8r8g8b8");
+}
+
 int ft_board_setup(void *blob, bd_t *bd)
 {
+	/*
+	 * For now, we simply always add the simplefb DT node. Later, we
+	 * should be more intelligent, and e.g. only do this if no enabled DT
+	 * node exists for the "real" graphics driver.
+	 */
+	lcd_dt_simplefb_add_node(blob);
+
 	return 0;
 }
 #endif