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diff --git a/Documentation/admin-guide/auxdisplay/cfag12864b.rst b/Documentation/admin-guide/auxdisplay/cfag12864b.rst new file mode 100644 index 0000000000..da385d851a --- /dev/null +++ b/Documentation/admin-guide/auxdisplay/cfag12864b.rst @@ -0,0 +1,98 @@ +=================================== +cfag12864b LCD Driver Documentation +=================================== + +:License: GPLv2 +:Author & Maintainer: Miguel Ojeda <ojeda@kernel.org> +:Date: 2006-10-27 + + + +.. INDEX + + 1. DRIVER INFORMATION + 2. DEVICE INFORMATION + 3. WIRING + 4. USERSPACE PROGRAMMING + +1. Driver Information +--------------------- + +This driver supports a cfag12864b LCD. + + +2. Device Information +--------------------- + +:Manufacturer: Crystalfontz +:Device Name: Crystalfontz 12864b LCD Series +:Device Code: cfag12864b +:Webpage: http://www.crystalfontz.com +:Device Webpage: http://www.crystalfontz.com/products/12864b/ +:Type: LCD (Liquid Crystal Display) +:Width: 128 +:Height: 64 +:Colors: 2 (B/N) +:Controller: ks0108 +:Controllers: 2 +:Pages: 8 each controller +:Addresses: 64 each page +:Data size: 1 byte each address +:Memory size: 2 * 8 * 64 * 1 = 1024 bytes = 1 Kbyte + + +3. Wiring +--------- + +The cfag12864b LCD Series don't have official wiring. + +The common wiring is done to the parallel port as shown:: + + Parallel Port cfag12864b + + Name Pin# Pin# Name + + Strobe ( 1)------------------------------(17) Enable + Data 0 ( 2)------------------------------( 4) Data 0 + Data 1 ( 3)------------------------------( 5) Data 1 + Data 2 ( 4)------------------------------( 6) Data 2 + Data 3 ( 5)------------------------------( 7) Data 3 + Data 4 ( 6)------------------------------( 8) Data 4 + Data 5 ( 7)------------------------------( 9) Data 5 + Data 6 ( 8)------------------------------(10) Data 6 + Data 7 ( 9)------------------------------(11) Data 7 + (10) [+5v]---( 1) Vdd + (11) [GND]---( 2) Ground + (12) [+5v]---(14) Reset + (13) [GND]---(15) Read / Write + Line (14)------------------------------(13) Controller Select 1 + (15) + Init (16)------------------------------(12) Controller Select 2 + Select (17)------------------------------(16) Data / Instruction + Ground (18)---[GND] [+5v]---(19) LED + + Ground (19)---[GND] + Ground (20)---[GND] E A Values: + Ground (21)---[GND] [GND]---[P1]---(18) Vee - R = Resistor = 22 ohm + Ground (22)---[GND] | - P1 = Preset = 10 Kohm + Ground (23)---[GND] ---- S ------( 3) V0 - P2 = Preset = 1 Kohm + Ground (24)---[GND] | | + Ground (25)---[GND] [GND]---[P2]---[R]---(20) LED - + + +4. Userspace Programming +------------------------ + +The cfag12864bfb describes a framebuffer device (/dev/fbX). + +It has a size of 1024 bytes = 1 Kbyte. +Each bit represents one pixel. If the bit is high, the pixel will +turn on. If the pixel is low, the pixel will turn off. + +You can use the framebuffer as a file: fopen, fwrite, fclose... +Although the LCD won't get updated until the next refresh time arrives. + +Also, you can mmap the framebuffer: open & mmap, munmap & close... +which is the best option for most uses. + +Check samples/auxdisplay/cfag12864b-example.c +for a real working userspace complete program with usage examples. |