simple-framebuffer is a new device tree binding that describes a pre- configured frame-buffer memory region and its format. The Linux kernel contains a driver that supports this binding. Implement functions to create a DT node (or fill in an existing node) with parameters that describe the framebuffer format that U-Boot is using.
This will be immediately used by the Raspberry Pi board in U-Boot, and likely will be used by the Samsung ARM ChromeBook support soon too. It could well be used by many other boards (e.g. Tegra boards with built-in LCD panels, which aren't yet supported by the Linux kernel).
Signed-off-by: Stephen Warren swarren@wwwdotorg.org --- v2: Add binding doc, remove ifdefs from lcd.h --- common/lcd.c | 87 ++++++++++++++++++++ .../video/simple-framebuffer.txt | 25 ++++++ include/lcd.h | 3 + 3 files changed, 115 insertions(+) create mode 100644 doc/device-tree-bindings/video/simple-framebuffer.txt
diff --git a/common/lcd.c b/common/lcd.c index edae835..3a60484 100644 --- a/common/lcd.c +++ b/common/lcd.c @@ -57,6 +57,10 @@ #include <atmel_lcdc.h> #endif
+#if defined(CONFIG_LCD_DT_SIMPLEFB) +#include <libfdt.h> +#endif + /************************************************************************/ /* ** FONT DATA */ /************************************************************************/ @@ -1182,3 +1186,86 @@ int lcd_get_screen_columns(void) { return CONSOLE_COLS; } + +#if defined(CONFIG_LCD_DT_SIMPLEFB) +static int lcd_dt_simplefb_configure_node(void *blob, int off) +{ + u32 stride; + fdt32_t cells[2]; + int ret; + const char format[] = +#if LCD_BPP == LCD_COLOR16 + "r5g6b5"; +#else + ""; +#endif + + if (!format[0]) + return -1; + + stride = panel_info.vl_col * 2; + + cells[0] = cpu_to_fdt32(gd->fb_base); + cells[1] = cpu_to_fdt32(stride * panel_info.vl_row); + ret = fdt_setprop(blob, off, "reg", cells, sizeof(cells[0]) * 2); + if (ret < 0) + return -1; + + cells[0] = cpu_to_fdt32(panel_info.vl_col); + ret = fdt_setprop(blob, off, "width", cells, sizeof(cells[0])); + if (ret < 0) + return -1; + + cells[0] = cpu_to_fdt32(panel_info.vl_row); + ret = fdt_setprop(blob, off, "height", cells, sizeof(cells[0])); + if (ret < 0) + return -1; + + cells[0] = cpu_to_fdt32(stride); + ret = fdt_setprop(blob, off, "stride", cells, sizeof(cells[0])); + if (ret < 0) + return -1; + + ret = fdt_setprop(blob, off, "format", format, strlen(format) + 1); + if (ret < 0) + return -1; + + ret = fdt_delprop(blob, off, "status"); + if (ret < 0) + return -1; + + return 0; +} + +int lcd_dt_simplefb_add_node(void *blob) +{ + const char compat[] = "simple-framebuffer"; + 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 lcd_dt_simplefb_configure_node(blob, off); +} + +int lcd_dt_simplefb_enable_existing_node(void *blob) +{ + int off; + + off = fdt_node_offset_by_compatible(blob, -1, "simple-framebuffer"); + if (off < 0) + return -1; + + return lcd_dt_simplefb_configure_node(blob, off); +} +#endif diff --git a/doc/device-tree-bindings/video/simple-framebuffer.txt b/doc/device-tree-bindings/video/simple-framebuffer.txt new file mode 100644 index 0000000..3ea4605 --- /dev/null +++ b/doc/device-tree-bindings/video/simple-framebuffer.txt @@ -0,0 +1,25 @@ +Simple Framebuffer + +A simple frame-buffer describes a raw memory region that may be rendered to, +with the assumption that the display hardware has already been set up to scan +out from that buffer. + +Required properties: +- compatible: "simple-framebuffer" +- reg: Should contain the location and size of the framebuffer memory. +- width: The width of the framebuffer in pixels. +- height: The height of the framebuffer in pixels. +- stride: The number of bytes in each line of the framebuffer. +- format: The format of the framebuffer surface. Valid values are: + - r5g6b5 (16-bit pixels, d[15:11]=r, d[10:5]=g, d[4:0]=b). + +Example: + + framebuffer { + compatible = "simple-framebuffer"; + reg = <0x1d385000 (1600 * 1200 * 2)>; + width = <1600>; + height = <1200>; + stride = <(1600 * 2)>; + format = "r5g6b5"; + }; diff --git a/include/lcd.h b/include/lcd.h index c6e7fc5..30225ed 100644 --- a/include/lcd.h +++ b/include/lcd.h @@ -324,6 +324,9 @@ void lcd_show_board_info(void); /* Return the size of the LCD frame buffer, and the line length */ int lcd_get_size(int *line_length);
+int lcd_dt_simplefb_add_node(void *blob); +int lcd_dt_simplefb_enable_existing_node(void *blob); + /************************************************************************/ /* ** BITMAP DISPLAY SUPPORT */ /************************************************************************/