| Ondrej Zajicek | 558b7bd | 2007-05-09 02:35:31 -0700 | [diff] [blame] | 1 | |
| 2 | vt8623fb - fbdev driver for graphics core in VIA VT8623 chipset |
| 3 | =============================================================== |
| 4 | |
| 5 | |
| 6 | Supported Hardware |
| 7 | ================== |
| 8 | |
| 9 | VIA VT8623 [CLE266] chipset and its graphics core |
| 10 | (known as CastleRock or Unichrome) |
| 11 | |
| 12 | I tested vt8623fb on VIA EPIA ML-6000 |
| 13 | |
| 14 | |
| 15 | Supported Features |
| 16 | ================== |
| 17 | |
| 18 | * 4 bpp pseudocolor modes (with 18bit palette, two variants) |
| 19 | * 8 bpp pseudocolor mode (with 18bit palette) |
| 20 | * 16 bpp truecolor mode (RGB 565) |
| 21 | * 32 bpp truecolor mode (RGB 888) |
| 22 | * text mode (activated by bpp = 0) |
| 23 | * doublescan mode variant (not available in text mode) |
| 24 | * panning in both directions |
| 25 | * suspend/resume support |
| 26 | * DPMS support |
| 27 | |
| 28 | Text mode is supported even in higher resolutions, but there is limitation to |
| 29 | lower pixclocks (maximum about 100 MHz). This limitation is not enforced by |
| 30 | driver. Text mode supports 8bit wide fonts only (hardware limitation) and |
| 31 | 16bit tall fonts (driver limitation). |
| 32 | |
| 33 | There are two 4 bpp modes. First mode (selected if nonstd == 0) is mode with |
| 34 | packed pixels, high nibble first. Second mode (selected if nonstd == 1) is mode |
| 35 | with interleaved planes (1 byte interleave), MSB first. Both modes support |
| 36 | 8bit wide fonts only (driver limitation). |
| 37 | |
| 38 | Suspend/resume works on systems that initialize video card during resume and |
| 39 | if device is active (for example used by fbcon). |
| 40 | |
| 41 | |
| 42 | Missing Features |
| 43 | ================ |
| 44 | (alias TODO list) |
| 45 | |
| 46 | * secondary (not initialized by BIOS) device support |
| 47 | * MMIO support |
| 48 | * interlaced mode variant |
| 49 | * support for fontwidths != 8 in 4 bpp modes |
| 50 | * support for fontheight != 16 in text mode |
| 51 | * hardware cursor |
| 52 | * video overlay support |
| 53 | * vsync synchronization |
| 54 | * acceleration support (8514-like 2D, busmaster transfers) |
| 55 | |
| 56 | |
| 57 | Known bugs |
| 58 | ========== |
| 59 | |
| 60 | * cursor disable in text mode doesn't work |
| 61 | |
| 62 | |
| 63 | -- |
| 64 | Ondrej Zajicek <santiago@crfreenet.org> |