| |
| vt8623fb - fbdev driver for graphics core in VIA VT8623 chipset |
| =============================================================== |
| |
| |
| Supported Hardware |
| ================== |
| |
| VIA VT8623 [CLE266] chipset and its graphics core |
| (known as CastleRock or Unichrome) |
| |
| I tested vt8623fb on VIA EPIA ML-6000 |
| |
| |
| Supported Features |
| ================== |
| |
| * 4 bpp pseudocolor modes (with 18bit palette, two variants) |
| * 8 bpp pseudocolor mode (with 18bit palette) |
| * 16 bpp truecolor mode (RGB 565) |
| * 32 bpp truecolor mode (RGB 888) |
| * text mode (activated by bpp = 0) |
| * doublescan mode variant (not available in text mode) |
| * panning in both directions |
| * suspend/resume support |
| * DPMS support |
| |
| Text mode is supported even in higher resolutions, but there is limitation to |
| lower pixclocks (maximum about 100 MHz). This limitation is not enforced by |
| driver. Text mode supports 8bit wide fonts only (hardware limitation) and |
| 16bit tall fonts (driver limitation). |
| |
| There are two 4 bpp modes. First mode (selected if nonstd == 0) is mode with |
| packed pixels, high nibble first. Second mode (selected if nonstd == 1) is mode |
| with interleaved planes (1 byte interleave), MSB first. Both modes support |
| 8bit wide fonts only (driver limitation). |
| |
| Suspend/resume works on systems that initialize video card during resume and |
| if device is active (for example used by fbcon). |
| |
| |
| Missing Features |
| ================ |
| (alias TODO list) |
| |
| * secondary (not initialized by BIOS) device support |
| * MMIO support |
| * interlaced mode variant |
| * support for fontwidths != 8 in 4 bpp modes |
| * support for fontheight != 16 in text mode |
| * hardware cursor |
| * video overlay support |
| * vsync synchronization |
| * acceleration support (8514-like 2D, busmaster transfers) |
| |
| |
| Known bugs |
| ========== |
| |
| * cursor disable in text mode doesn't work |
| |
| |
| -- |
| Ondrej Zajicek <santiago@crfreenet.org> |
