1*4882a593Smuzhiyun=============================================================== 2*4882a593Smuzhiyunvt8623fb - fbdev driver for graphics core in VIA VT8623 chipset 3*4882a593Smuzhiyun=============================================================== 4*4882a593Smuzhiyun 5*4882a593Smuzhiyun 6*4882a593SmuzhiyunSupported Hardware 7*4882a593Smuzhiyun================== 8*4882a593Smuzhiyun 9*4882a593SmuzhiyunVIA VT8623 [CLE266] chipset and its graphics core 10*4882a593Smuzhiyun(known as CastleRock or Unichrome) 11*4882a593Smuzhiyun 12*4882a593SmuzhiyunI tested vt8623fb on VIA EPIA ML-6000 13*4882a593Smuzhiyun 14*4882a593Smuzhiyun 15*4882a593SmuzhiyunSupported Features 16*4882a593Smuzhiyun================== 17*4882a593Smuzhiyun 18*4882a593Smuzhiyun * 4 bpp pseudocolor modes (with 18bit palette, two variants) 19*4882a593Smuzhiyun * 8 bpp pseudocolor mode (with 18bit palette) 20*4882a593Smuzhiyun * 16 bpp truecolor mode (RGB 565) 21*4882a593Smuzhiyun * 32 bpp truecolor mode (RGB 888) 22*4882a593Smuzhiyun * text mode (activated by bpp = 0) 23*4882a593Smuzhiyun * doublescan mode variant (not available in text mode) 24*4882a593Smuzhiyun * panning in both directions 25*4882a593Smuzhiyun * suspend/resume support 26*4882a593Smuzhiyun * DPMS support 27*4882a593Smuzhiyun 28*4882a593SmuzhiyunText mode is supported even in higher resolutions, but there is limitation to 29*4882a593Smuzhiyunlower pixclocks (maximum about 100 MHz). This limitation is not enforced by 30*4882a593Smuzhiyundriver. Text mode supports 8bit wide fonts only (hardware limitation) and 31*4882a593Smuzhiyun16bit tall fonts (driver limitation). 32*4882a593Smuzhiyun 33*4882a593SmuzhiyunThere are two 4 bpp modes. First mode (selected if nonstd == 0) is mode with 34*4882a593Smuzhiyunpacked pixels, high nibble first. Second mode (selected if nonstd == 1) is mode 35*4882a593Smuzhiyunwith interleaved planes (1 byte interleave), MSB first. Both modes support 36*4882a593Smuzhiyun8bit wide fonts only (driver limitation). 37*4882a593Smuzhiyun 38*4882a593SmuzhiyunSuspend/resume works on systems that initialize video card during resume and 39*4882a593Smuzhiyunif device is active (for example used by fbcon). 40*4882a593Smuzhiyun 41*4882a593Smuzhiyun 42*4882a593SmuzhiyunMissing Features 43*4882a593Smuzhiyun================ 44*4882a593Smuzhiyun(alias TODO list) 45*4882a593Smuzhiyun 46*4882a593Smuzhiyun * secondary (not initialized by BIOS) device support 47*4882a593Smuzhiyun * MMIO support 48*4882a593Smuzhiyun * interlaced mode variant 49*4882a593Smuzhiyun * support for fontwidths != 8 in 4 bpp modes 50*4882a593Smuzhiyun * support for fontheight != 16 in text mode 51*4882a593Smuzhiyun * hardware cursor 52*4882a593Smuzhiyun * video overlay support 53*4882a593Smuzhiyun * vsync synchronization 54*4882a593Smuzhiyun * acceleration support (8514-like 2D, busmaster transfers) 55*4882a593Smuzhiyun 56*4882a593Smuzhiyun 57*4882a593SmuzhiyunKnown bugs 58*4882a593Smuzhiyun========== 59*4882a593Smuzhiyun 60*4882a593Smuzhiyun * cursor disable in text mode doesn't work 61*4882a593Smuzhiyun 62*4882a593Smuzhiyun 63*4882a593Smuzhiyun-- 64*4882a593SmuzhiyunOndrej Zajicek <santiago@crfreenet.org> 65