xref: /openbmc/linux/drivers/staging/sm750fb/readme (revision 69e98df7)
181dee67eSSudip MukherjeeIntroduction:
281dee67eSSudip Mukherjee	SM750 of Silicon MOtion is pci express display controller device.
381dee67eSSudip Mukherjee	The SM750 embedded graphics features include:
481dee67eSSudip Mukherjee	- dual display
581dee67eSSudip Mukherjee	- 2D acceleration
681dee67eSSudip Mukherjee	- 16MB integrated video memory
781dee67eSSudip Mukherjee
869e98df7SCarlos E. GarciaAbout the kernel module parameter of driver:
981dee67eSSudip Mukherjee
1081dee67eSSudip Mukherjee	Use 1280,8bpp index color and 60 hz mode:
1181dee67eSSudip Mukherjee	insmod ./sm750fb.ko g_option="1280x1024-8@60"
1281dee67eSSudip Mukherjee
1381dee67eSSudip Mukherjee	Disable MTRR,Disable 2d acceleration,Disable hardware cursor,
1481dee67eSSudip Mukherjee	and use a 800x600 mode :
1581dee67eSSudip Mukherjee	insmod ./sm750fb.ko g_option="noaccel:nomtrr:nohwc:800x600"
1681dee67eSSudip Mukherjee
1781dee67eSSudip Mukherjee	dual frame buffer for driver with "dual" parameter
1881dee67eSSudip Mukherjee	insmod ./sm750fb.ko g_option="dual,800x600:1024x768"
1981dee67eSSudip Mukherjee	it will create fb0 and fb1 (or fb1,fb2 if fb0 already exist) under /dev
2081dee67eSSudip Mukherjee	and user can use con2fb to link fbX and ttyX
2181dee67eSSudip Mukherjee
2281dee67eSSudip Mukherjee	Notes:
2369e98df7SCarlos E. Garcia	1) if you build the driver with built-in method, the parameter
2481dee67eSSudip Mukherjee		you edited in the grub config file will be also the
2569e98df7SCarlos E. Garcia		same format as above modular method,but additionally add
2681dee67eSSudip Mukherjee		"video=sm750fb:"
2781dee67eSSudip Mukherjee		ahead of parameters,so,it looks like:
2881dee67eSSudip Mukherjee		video=sm750fb:noaccel,1280x1024@60,otherparam,etc...
2981dee67eSSudip Mukherjee		it equal to modular method with below command:
3081dee67eSSudip Mukherjee		insmod ./sm750fb.ko g_option="noaccel:1280x1024@60:otherparm:etc..."
3181dee67eSSudip Mukherjee
3269e98df7SCarlos E. Garcia	2) if you put 800x600 into the parameter without bpp and
3381dee67eSSudip Mukherjee		refresh rate, kernel driver will defaulty use 16bpp and 60hz
3481dee67eSSudip Mukherjee
3581dee67eSSudip MukherjeeImportant:
3681dee67eSSudip Mukherjee	if you have vesafb enabled in your config then /dev/fb0 will be created by vesafb
3781dee67eSSudip Mukherjee	and this driver will use fb1, fb2. In that case, you need to configure your X-server
3881dee67eSSudip Mukherjee	to use fb1. Another simple althernative is to disable vesafb from your config.
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