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| -rw-r--r-- | Documentation/fb/viafb.txt | 252 |
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diff --git a/Documentation/fb/viafb.txt b/Documentation/fb/viafb.txt new file mode 100644 index 000000000..1cb2462a7 --- /dev/null +++ b/Documentation/fb/viafb.txt @@ -0,0 +1,252 @@ + + VIA Integration Graphic Chip Console Framebuffer Driver + +[Platform] +----------------------- + The console framebuffer driver is for graphics chips of + VIA UniChrome Family(CLE266, PM800 / CN400 / CN300, + P4M800CE / P4M800Pro / CN700 / VN800, + CX700 / VX700, K8M890, P4M890, + CN896 / P4M900, VX800, VX855) + +[Driver features] +------------------------ + Device: CRT, LCD, DVI + + Support viafb_mode: + CRT: + 640x480(60, 75, 85, 100, 120 Hz), 720x480(60 Hz), + 720x576(60 Hz), 800x600(60, 75, 85, 100, 120 Hz), + 848x480(60 Hz), 856x480(60 Hz), 1024x512(60 Hz), + 1024x768(60, 75, 85, 100 Hz), 1152x864(75 Hz), + 1280x768(60 Hz), 1280x960(60 Hz), 1280x1024(60, 75, 85 Hz), + 1440x1050(60 Hz), 1600x1200(60, 75 Hz), 1280x720(60 Hz), + 1920x1080(60 Hz), 1400x1050(60 Hz), 800x480(60 Hz) + + color depth: 8 bpp, 16 bpp, 32 bpp supports. + + Support 2D hardware accelerator. + +[Using the viafb module] +-- -- -------------------- + Start viafb with default settings: + #modprobe viafb + + Start viafb with user options: + #modprobe viafb viafb_mode=800x600 viafb_bpp=16 viafb_refresh=60 + viafb_active_dev=CRT+DVI viafb_dvi_port=DVP1 + viafb_mode1=1024x768 viafb_bpp=16 viafb_refresh1=60 + viafb_SAMM_ON=1 + + viafb_mode: + 640x480 (default) + 720x480 + 800x600 + 1024x768 + ...... + + viafb_bpp: + 8, 16, 32 (default:32) + + viafb_refresh: + 60, 75, 85, 100, 120 (default:60) + + viafb_lcd_dsp_method: + 0 : expansion (default) + 1 : centering + + viafb_lcd_mode: + 0 : LCD panel with LSB data format input (default) + 1 : LCD panel with MSB data format input + + viafb_lcd_panel_id: + 0 : Resolution: 640x480, Channel: single, Dithering: Enable + 1 : Resolution: 800x600, Channel: single, Dithering: Enable + 2 : Resolution: 1024x768, Channel: single, Dithering: Enable (default) + 3 : Resolution: 1280x768, Channel: single, Dithering: Enable + 4 : Resolution: 1280x1024, Channel: dual, Dithering: Enable + 5 : Resolution: 1400x1050, Channel: dual, Dithering: Enable + 6 : Resolution: 1600x1200, Channel: dual, Dithering: Enable + + 8 : Resolution: 800x480, Channel: single, Dithering: Enable + 9 : Resolution: 1024x768, Channel: dual, Dithering: Enable + 10: Resolution: 1024x768, Channel: single, Dithering: Disable + 11: Resolution: 1024x768, Channel: dual, Dithering: Disable + 12: Resolution: 1280x768, Channel: single, Dithering: Disable + 13: Resolution: 1280x1024, Channel: dual, Dithering: Disable + 14: Resolution: 1400x1050, Channel: dual, Dithering: Disable + 15: Resolution: 1600x1200, Channel: dual, Dithering: Disable + 16: Resolution: 1366x768, Channel: single, Dithering: Disable + 17: Resolution: 1024x600, Channel: single, Dithering: Enable + 18: Resolution: 1280x768, Channel: dual, Dithering: Enable + 19: Resolution: 1280x800, Channel: single, Dithering: Enable + + viafb_accel: + 0 : No 2D Hardware Acceleration + 1 : 2D Hardware Acceleration (default) + + viafb_SAMM_ON: + 0 : viafb_SAMM_ON disable (default) + 1 : viafb_SAMM_ON enable + + viafb_mode1: (secondary display device) + 640x480 (default) + 720x480 + 800x600 + 1024x768 + ... ... + + viafb_bpp1: (secondary display device) + 8, 16, 32 (default:32) + + viafb_refresh1: (secondary display device) + 60, 75, 85, 100, 120 (default:60) + + viafb_active_dev: + This option is used to specify active devices.(CRT, DVI, CRT+LCD...) + DVI stands for DVI or HDMI, E.g., If you want to enable HDMI, + set viafb_active_dev=DVI. In SAMM case, the previous of + viafb_active_dev is primary device, and the following is + secondary device. + + For example: + To enable one device, such as DVI only, we can use: + modprobe viafb viafb_active_dev=DVI + To enable two devices, such as CRT+DVI: + modprobe viafb viafb_active_dev=CRT+DVI; + + For DuoView case, we can use: + modprobe viafb viafb_active_dev=CRT+DVI + OR + modprobe viafb viafb_active_dev=DVI+CRT... + + For SAMM case: + If CRT is primary and DVI is secondary, we should use: + modprobe viafb viafb_active_dev=CRT+DVI viafb_SAMM_ON=1... + If DVI is primary and CRT is secondary, we should use: + modprobe viafb viafb_active_dev=DVI+CRT viafb_SAMM_ON=1... + + viafb_display_hardware_layout: + This option is used to specify display hardware layout for CX700 chip. + 1 : LCD only + 2 : DVI only + 3 : LCD+DVI (default) + 4 : LCD1+LCD2 (internal + internal) + 16: LCD1+ExternalLCD2 (internal + external) + + viafb_second_size: + This option is used to set second device memory size(MB) in SAMM case. + The minimal size is 16. + + viafb_platform_epia_dvi: + This option is used to enable DVI on EPIA - M + 0 : No DVI on EPIA - M (default) + 1 : DVI on EPIA - M + + viafb_bus_width: + When using 24 - Bit Bus Width Digital Interface, + this option should be set. + 12: 12-Bit LVDS or 12-Bit TMDS (default) + 24: 24-Bit LVDS or 24-Bit TMDS + + viafb_device_lcd_dualedge: + When using Dual Edge Panel, this option should be set. + 0 : No Dual Edge Panel (default) + 1 : Dual Edge Panel + + viafb_lcd_port: + This option is used to specify LCD output port, + available values are "DVP0" "DVP1" "DFP_HIGHLOW" "DFP_HIGH" "DFP_LOW". + for external LCD + external DVI on CX700(External LCD is on DVP0), + we should use: + modprobe viafb viafb_lcd_port=DVP0... + +Notes: + 1. CRT may not display properly for DuoView CRT & DVI display at + the "640x480" PAL mode with DVI overscan enabled. + 2. SAMM stands for single adapter multi monitors. It is different from + multi-head since SAMM support multi monitor at driver layers, thus fbcon + layer doesn't even know about it; SAMM's second screen doesn't have a + device node file, thus a user mode application can't access it directly. + When SAMM is enabled, viafb_mode and viafb_mode1, viafb_bpp and + viafb_bpp1, viafb_refresh and viafb_refresh1 can be different. + 3. When console is depending on viafbinfo1, dynamically change resolution + and bpp, need to call VIAFB specified ioctl interface VIAFB_SET_DEVICE + instead of calling common ioctl function FBIOPUT_VSCREENINFO since + viafb doesn't support multi-head well, or it will cause screen crush. + + +[Configure viafb with "fbset" tool] +----------------------------------- + "fbset" is an inbox utility of Linux. + 1. Inquire current viafb information, type, + # fbset -i + + 2. Set various resolutions and viafb_refresh rates, + # fbset <resolution-vertical_sync> + + example, + # fbset "1024x768-75" + or + # fbset -g 1024 768 1024 768 32 + Check the file "/etc/fb.modes" to find display modes available. + + 3. Set the color depth, + # fbset -depth <value> + + example, + # fbset -depth 16 + + +[Configure viafb via /proc] +--------------------------- + The following files exist in /proc/viafb + + supported_output_devices + + This read-only file contains a full ',' separated list containing all + output devices that could be available on your platform. It is likely + that not all of those have a connector on your hardware but it should + provide a good starting point to figure out which of those names match + a real connector. + Example: + # cat /proc/viafb/supported_output_devices + + iga1/output_devices + iga2/output_devices + + These two files are readable and writable. iga1 and iga2 are the two + independent units that produce the screen image. Those images can be + forwarded to one or more output devices. Reading those files is a way + to query which output devices are currently used by an iga. + Example: + # cat /proc/viafb/iga1/output_devices + If there are no output devices printed the output of this iga is lost. + This can happen for example if only one (the other) iga is used. + Writing to these files allows adjusting the output devices during + runtime. One can add new devices, remove existing ones or switch + between igas. Essentially you can write a ',' separated list of device + names (or a single one) in the same format as the output to those + files. You can add a '+' or '-' as a prefix allowing simple addition + and removal of devices. So a prefix '+' adds the devices from your list + to the already existing ones, '-' removes the listed devices from the + existing ones and if no prefix is given it replaces all existing ones + with the listed ones. If you remove devices they are expected to turn + off. If you add devices that are already part of the other iga they are + removed there and added to the new one. + Examples: + Add CRT as output device to iga1 + # echo +CRT > /proc/viafb/iga1/output_devices + + Remove (turn off) DVP1 and LVDS1 as output devices of iga2 + # echo -DVP1,LVDS1 > /proc/viafb/iga2/output_devices + + Replace all iga1 output devices by CRT + # echo CRT > /proc/viafb/iga1/output_devices + + +[Bootup with viafb]: +-------------------- + Add the following line to your grub.conf: + append = "video=viafb:viafb_mode=1024x768,viafb_bpp=32,viafb_refresh=85" + |