Merge branch 'spi' of git://gitorious.org/linus-tree/linus-tree into spi/next
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / Documentation / fb / matroxfb.txt
1 [This file is cloned from VesaFB. Thanks go to Gerd Knorr]
2
3 What is matroxfb?
4 =================
5
6 This is a driver for a graphic framebuffer for Matrox devices on
7 Alpha, Intel and PPC boxes.
8
9 Advantages:
10
11 * It provides a nice large console (128 cols + 48 lines with 1024x768)
12 without using tiny, unreadable fonts.
13 * You can run XF{68,86}_FBDev or XFree86 fbdev driver on top of /dev/fb0
14 * Most important: boot logo :-)
15
16 Disadvantages:
17
18 * graphic mode is slower than text mode... but you should not notice
19 if you use same resolution as you used in textmode.
20
21
22 How to use it?
23 ==============
24
25 Switching modes is done using the video=matroxfb:vesa:... boot parameter
26 or using `fbset' program.
27
28 If you want, for example, enable a resolution of 1280x1024x24bpp you should
29 pass to the kernel this command line: "video=matroxfb:vesa:0x1BB".
30
31 You should compile in both vgacon (to boot if you remove you Matrox from
32 box) and matroxfb (for graphics mode). You should not compile-in vesafb
33 unless you have primary display on non-Matrox VBE2.0 device (see
34 Documentation/fb/vesafb.txt for details).
35
36 Currently supported video modes are (through vesa:... interface, PowerMac
37 has [as addon] compatibility code):
38
39
40 [Graphic modes]
41
42 bpp | 640x400 640x480 768x576 800x600 960x720
43 ----+--------------------------------------------
44 4 | 0x12 0x102
45 8 | 0x100 0x101 0x180 0x103 0x188
46 15 | 0x110 0x181 0x113 0x189
47 16 | 0x111 0x182 0x114 0x18A
48 24 | 0x1B2 0x184 0x1B5 0x18C
49 32 | 0x112 0x183 0x115 0x18B
50
51
52 [Graphic modes (continued)]
53
54 bpp | 1024x768 1152x864 1280x1024 1408x1056 1600x1200
55 ----+------------------------------------------------
56 4 | 0x104 0x106
57 8 | 0x105 0x190 0x107 0x198 0x11C
58 15 | 0x116 0x191 0x119 0x199 0x11D
59 16 | 0x117 0x192 0x11A 0x19A 0x11E
60 24 | 0x1B8 0x194 0x1BB 0x19C 0x1BF
61 32 | 0x118 0x193 0x11B 0x19B
62
63
64 [Text modes]
65
66 text | 640x400 640x480 1056x344 1056x400 1056x480
67 -----+------------------------------------------------
68 8x8 | 0x1C0 0x108 0x10A 0x10B 0x10C
69 8x16 | 2, 3, 7 0x109
70
71 You can enter these number either hexadecimal (leading `0x') or decimal
72 (0x100 = 256). You can also use value + 512 to achieve compatibility
73 with your old number passed to vesafb.
74
75 Non-listed number can be achieved by more complicated command-line, for
76 example 1600x1200x32bpp can be specified by `video=matroxfb:vesa:0x11C,depth:32'.
77
78
79 X11
80 ===
81
82 XF{68,86}_FBDev should work just fine, but it is non-accelerated. On non-intel
83 architectures there are some glitches for 24bpp videomodes. 8, 16 and 32bpp
84 works fine.
85
86 Running another (accelerated) X-Server like XF86_SVGA works too. But (at least)
87 XFree servers have big troubles in multihead configurations (even on first
88 head, not even talking about second). Running XFree86 4.x accelerated mga
89 driver is possible, but you must not enable DRI - if you do, resolution and
90 color depth of your X desktop must match resolution and color depths of your
91 virtual consoles, otherwise X will corrupt accelerator settings.
92
93
94 SVGALib
95 =======
96
97 Driver contains SVGALib compatibility code. It is turned on by choosing textual
98 mode for console. You can do it at boot time by using videomode
99 2,3,7,0x108-0x10C or 0x1C0. At runtime, `fbset -depth 0' does this work.
100 Unfortunately, after SVGALib application exits, screen contents is corrupted.
101 Switching to another console and back fixes it. I hope that it is SVGALib's
102 problem and not mine, but I'm not sure.
103
104
105 Configuration
106 =============
107
108 You can pass kernel command line options to matroxfb with
109 `video=matroxfb:option1,option2:value2,option3' (multiple options should be
110 separated by comma, values are separated from options by `:').
111 Accepted options:
112
113 mem:X - size of memory (X can be in megabytes, kilobytes or bytes)
114 You can only decrease value determined by driver because of
115 it always probe for memory. Default is to use whole detected
116 memory usable for on-screen display (i.e. max. 8 MB).
117 disabled - do not load driver; you can use also `off', but `disabled'
118 is here too.
119 enabled - load driver, if you have `video=matroxfb:disabled' in LILO
120 configuration, you can override it by this (you cannot override
121 `off'). It is default.
122 noaccel - do not use acceleration engine. It does not work on Alphas.
123 accel - use acceleration engine. It is default.
124 nopan - create initial consoles with vyres = yres, thus disabling virtual
125 scrolling.
126 pan - create initial consoles as tall as possible (vyres = memory/vxres).
127 It is default.
128 nopciretry - disable PCI retries. It is needed for some broken chipsets,
129 it is autodetected for intel's 82437. In this case device does
130 not comply to PCI 2.1 specs (it will not guarantee that every
131 transaction terminate with success or retry in 32 PCLK).
132 pciretry - enable PCI retries. It is default, except for intel's 82437.
133 novga - disables VGA I/O ports. It is default if BIOS did not enable device.
134 You should not use this option, some boards then do not restart
135 without power off.
136 vga - preserve state of VGA I/O ports. It is default. Driver does not
137 enable VGA I/O if BIOS did not it (it is not safe to enable it in
138 most cases).
139 nobios - disables BIOS ROM. It is default if BIOS did not enable BIOS itself.
140 You should not use this option, some boards then do not restart
141 without power off.
142 bios - preserve state of BIOS ROM. It is default. Driver does not enable
143 BIOS if BIOS was not enabled before.
144 noinit - tells driver, that devices were already initialized. You should use
145 it if you have G100 and/or if driver cannot detect memory, you see
146 strange pattern on screen and so on. Devices not enabled by BIOS
147 are still initialized. It is default.
148 init - driver initializes every device it knows about.
149 memtype - specifies memory type, implies 'init'. This is valid only for G200
150 and G400 and has following meaning:
151 G200: 0 -> 2x128Kx32 chips, 2MB onboard, probably sgram
152 1 -> 2x128Kx32 chips, 4MB onboard, probably sgram
153 2 -> 2x256Kx32 chips, 4MB onboard, probably sgram
154 3 -> 2x256Kx32 chips, 8MB onboard, probably sgram
155 4 -> 2x512Kx16 chips, 8/16MB onboard, probably sdram only
156 5 -> same as above
157 6 -> 4x128Kx32 chips, 4MB onboard, probably sgram
158 7 -> 4x128Kx32 chips, 8MB onboard, probably sgram
159 G400: 0 -> 2x512Kx16 SDRAM, 16/32MB
160 2x512Kx32 SGRAM, 16/32MB
161 1 -> 2x256Kx32 SGRAM, 8/16MB
162 2 -> 4x128Kx32 SGRAM, 8/16MB
163 3 -> 4x512Kx32 SDRAM, 32MB
164 4 -> 4x256Kx32 SGRAM, 16/32MB
165 5 -> 2x1Mx32 SDRAM, 32MB
166 6 -> reserved
167 7 -> reserved
168 You should use sdram or sgram parameter in addition to memtype
169 parameter.
170 nomtrr - disables write combining on frame buffer. This slows down driver but
171 there is reported minor incompatibility between GUS DMA and XFree
172 under high loads if write combining is enabled (sound dropouts).
173 mtrr - enables write combining on frame buffer. It speeds up video accesses
174 much. It is default. You must have MTRR support enabled in kernel
175 and your CPU must have MTRR (f.e. Pentium II have them).
176 sgram - tells to driver that you have Gxx0 with SGRAM memory. It has no
177 effect without `init'.
178 sdram - tells to driver that you have Gxx0 with SDRAM memory.
179 It is a default.
180 inv24 - change timings parameters for 24bpp modes on Millennium and
181 Millennium II. Specify this if you see strange color shadows around
182 characters.
183 noinv24 - use standard timings. It is the default.
184 inverse - invert colors on screen (for LCD displays)
185 noinverse - show true colors on screen. It is default.
186 dev:X - bind driver to device X. Driver numbers device from 0 up to N,
187 where device 0 is first `known' device found, 1 second and so on.
188 lspci lists devices in this order.
189 Default is `every' known device.
190 nohwcursor - disables hardware cursor (use software cursor instead).
191 hwcursor - enables hardware cursor. It is default. If you are using
192 non-accelerated mode (`noaccel' or `fbset -accel false'), software
193 cursor is used (except for text mode).
194 noblink - disables cursor blinking. Cursor in text mode always blinks (hw
195 limitation).
196 blink - enables cursor blinking. It is default.
197 nofastfont - disables fastfont feature. It is default.
198 fastfont:X - enables fastfont feature. X specifies size of memory reserved for
199 font data, it must be >= (fontwidth*fontheight*chars_in_font)/8.
200 It is faster on Gx00 series, but slower on older cards.
201 grayscale - enable grayscale summing. It works in PSEUDOCOLOR modes (text,
202 4bpp, 8bpp). In DIRECTCOLOR modes it is limited to characters
203 displayed through putc/putcs. Direct accesses to framebuffer
204 can paint colors.
205 nograyscale - disable grayscale summing. It is default.
206 cross4MB - enables that pixel line can cross 4MB boundary. It is default for
207 non-Millennium.
208 nocross4MB - pixel line must not cross 4MB boundary. It is default for
209 Millennium I or II, because of these devices have hardware
210 limitations which do not allow this. But this option is
211 incompatible with some (if not all yet released) versions of
212 XF86_FBDev.
213 dfp - enables digital flat panel interface. This option is incompatible with
214 secondary (TV) output - if DFP is active, TV output must be
215 inactive and vice versa. DFP always uses same timing as primary
216 (monitor) output.
217 dfp:X - use settings X for digital flat panel interface. X is number from
218 0 to 0xFF, and meaning of each individual bit is described in
219 G400 manual, in description of DAC register 0x1F. For normal operation
220 you should set all bits to zero, except lowest bit. This lowest bit
221 selects who is source of display clocks, whether G400, or panel.
222 Default value is now read back from hardware - so you should specify
223 this value only if you are also using `init' parameter.
224 outputs:XYZ - set mapping between CRTC and outputs. Each letter can have value
225 of 0 (for no CRTC), 1 (CRTC1) or 2 (CRTC2), and first letter corresponds
226 to primary analog output, second letter to the secondary analog output
227 and third letter to the DVI output. Default setting is 100 for
228 cards below G400 or G400 without DFP, 101 for G400 with DFP, and
229 111 for G450 and G550. You can set mapping only on first card,
230 use matroxset for setting up other devices.
231 vesa:X - selects startup videomode. X is number from 0 to 0x1FF, see table
232 above for detailed explanation. Default is 640x480x8bpp if driver
233 has 8bpp support. Otherwise first available of 640x350x4bpp,
234 640x480x15bpp, 640x480x24bpp, 640x480x32bpp or 80x25 text
235 (80x25 text is always available).
236
237 If you are not satisfied with videomode selected by `vesa' option, you
238 can modify it with these options:
239
240 xres:X - horizontal resolution, in pixels. Default is derived from `vesa'
241 option.
242 yres:X - vertical resolution, in pixel lines. Default is derived from `vesa'
243 option.
244 upper:X - top boundary: lines between end of VSYNC pulse and start of first
245 pixel line of picture. Default is derived from `vesa' option.
246 lower:X - bottom boundary: lines between end of picture and start of VSYNC
247 pulse. Default is derived from `vesa' option.
248 vslen:X - length of VSYNC pulse, in lines. Default is derived from `vesa'
249 option.
250 left:X - left boundary: pixels between end of HSYNC pulse and first pixel.
251 Default is derived from `vesa' option.
252 right:X - right boundary: pixels between end of picture and start of HSYNC
253 pulse. Default is derived from `vesa' option.
254 hslen:X - length of HSYNC pulse, in pixels. Default is derived from `vesa'
255 option.
256 pixclock:X - dotclocks, in ps (picoseconds). Default is derived from `vesa'
257 option and from `fh' and `fv' options.
258 sync:X - sync. pulse - bit 0 inverts HSYNC polarity, bit 1 VSYNC polarity.
259 If bit 3 (value 0x08) is set, composite sync instead of HSYNC is
260 generated. If bit 5 (value 0x20) is set, sync on green is turned on.
261 Do not forget that if you want sync on green, you also probably
262 want composite sync.
263 Default depends on `vesa'.
264 depth:X - Bits per pixel: 0=text, 4,8,15,16,24 or 32. Default depends on
265 `vesa'.
266
267 If you know capabilities of your monitor, you can specify some (or all) of
268 `maxclk', `fh' and `fv'. In this case, `pixclock' is computed so that
269 pixclock <= maxclk, real_fh <= fh and real_fv <= fv.
270
271 maxclk:X - maximum dotclock. X can be specified in MHz, kHz or Hz. Default is
272 `don't care'.
273 fh:X - maximum horizontal synchronization frequency. X can be specified
274 in kHz or Hz. Default is `don't care'.
275 fv:X - maximum vertical frequency. X must be specified in Hz. Default is
276 70 for modes derived from `vesa' with yres <= 400, 60Hz for
277 yres > 400.
278
279
280 Limitations
281 ===========
282
283 There are known and unknown bugs, features and misfeatures.
284 Currently there are following known bugs:
285 + SVGALib does not restore screen on exit
286 + generic fbcon-cfbX procedures do not work on Alphas. Due to this,
287 `noaccel' (and cfb4 accel) driver does not work on Alpha. So everyone
288 with access to /dev/fb* on Alpha can hang machine (you should restrict
289 access to /dev/fb* - everyone with access to this device can destroy
290 your monitor, believe me...).
291 + 24bpp does not support correctly XF-FBDev on big-endian architectures.
292 + interlaced text mode is not supported; it looks like hardware limitation,
293 but I'm not sure.
294 + Gxx0 SGRAM/SDRAM is not autodetected.
295 + If you are using more than one framebuffer device, you must boot kernel
296 with 'video=scrollback:0'.
297 + maybe more...
298 And following misfeatures:
299 + SVGALib does not restore screen on exit.
300 + pixclock for text modes is limited by hardware to
301 83 MHz on G200
302 66 MHz on Millennium I
303 60 MHz on Millennium II
304 Because I have no access to other devices, I do not know specific
305 frequencies for them. So driver does not check this and allows you to
306 set frequency higher that this. It causes sparks, black holes and other
307 pretty effects on screen. Device was not destroyed during tests. :-)
308 + my Millennium G200 oscillator has frequency range from 35 MHz to 380 MHz
309 (and it works with 8bpp on about 320 MHz dotclocks (and changed mclk)).
310 But Matrox says on product sheet that VCO limit is 50-250 MHz, so I believe
311 them (maybe that chip overheats, but it has a very big cooler (G100 has
312 none), so it should work).
313 + special mixed video/graphics videomodes of Mystique and Gx00 - 2G8V16 and
314 G16V16 are not supported
315 + color keying is not supported
316 + feature connector of Mystique and Gx00 is set to VGA mode (it is disabled
317 by BIOS)
318 + DDC (monitor detection) is supported through dualhead driver
319 + some check for input values are not so strict how it should be (you can
320 specify vslen=4000 and so on).
321 + maybe more...
322 And following features:
323 + 4bpp is available only on Millennium I and Millennium II. It is hardware
324 limitation.
325 + selection between 1:5:5:5 and 5:6:5 16bpp videomode is done by -rgba
326 option of fbset: "fbset -depth 16 -rgba 5,5,5" selects 1:5:5:5, anything
327 else selects 5:6:5 mode.
328 + text mode uses 6 bit VGA palette instead of 8 bit (one of 262144 colors
329 instead of one of 16M colors). It is due to hardware limitation of
330 Millennium I/II and SVGALib compatibility.
331
332
333 Benchmarks
334 ==========
335 It is time to redraw whole screen 1000 times in 1024x768, 60Hz. It is
336 time for draw 6144000 characters on screen through /dev/vcsa
337 (for 32bpp it is about 3GB of data (exactly 3000 MB); for 8x16 font in
338 16 seconds, i.e. 187 MBps).
339 Times were obtained from one older version of driver, now they are about 3%
340 faster, it is kernel-space only time on P-II/350 MHz, Millennium I in 33 MHz
341 PCI slot, G200 in AGP 2x slot. I did not test vgacon.
342
343 NOACCEL
344 8x16 12x22
345 Millennium I G200 Millennium I G200
346 8bpp 16.42 9.54 12.33 9.13
347 16bpp 21.00 15.70 19.11 15.02
348 24bpp 36.66 36.66 35.00 35.00
349 32bpp 35.00 30.00 33.85 28.66
350
351 ACCEL, nofastfont
352 8x16 12x22 6x11
353 Millennium I G200 Millennium I G200 Millennium I G200
354 8bpp 7.79 7.24 13.55 7.78 30.00 21.01
355 16bpp 9.13 7.78 16.16 7.78 30.00 21.01
356 24bpp 14.17 10.72 18.69 10.24 34.99 21.01
357 32bpp 16.15 16.16 18.73 13.09 34.99 21.01
358
359 ACCEL, fastfont
360 8x16 12x22 6x11
361 Millennium I G200 Millennium I G200 Millennium I G200
362 8bpp 8.41 6.01 6.54 4.37 16.00 10.51
363 16bpp 9.54 9.12 8.76 6.17 17.52 14.01
364 24bpp 15.00 12.36 11.67 10.00 22.01 18.32
365 32bpp 16.18 18.29* 12.71 12.74 24.44 21.00
366
367 TEXT
368 8x16
369 Millennium I G200
370 TEXT 3.29 1.50
371
372 * Yes, it is slower than Millennium I.
373
374
375 Dualhead G400
376 =============
377 Driver supports dualhead G400 with some limitations:
378 + secondary head shares videomemory with primary head. It is not problem
379 if you have 32MB of videoram, but if you have only 16MB, you may have
380 to think twice before choosing videomode (for example twice 1880x1440x32bpp
381 is not possible).
382 + due to hardware limitation, secondary head can use only 16 and 32bpp
383 videomodes.
384 + secondary head is not accelerated. There were bad problems with accelerated
385 XFree when secondary head used to use acceleration.
386 + secondary head always powerups in 640x480@60-32 videomode. You have to use
387 fbset to change this mode.
388 + secondary head always powerups in monitor mode. You have to use fbmatroxset
389 to change it to TV mode. Also, you must select at least 525 lines for
390 NTSC output and 625 lines for PAL output.
391 + kernel is not fully multihead ready. So some things are impossible to do.
392 + if you compiled it as module, you must insert i2c-matroxfb, matroxfb_maven
393 and matroxfb_crtc2 into kernel.
394
395
396 Dualhead G450
397 =============
398 Driver supports dualhead G450 with some limitations:
399 + secondary head shares videomemory with primary head. It is not problem
400 if you have 32MB of videoram, but if you have only 16MB, you may have
401 to think twice before choosing videomode.
402 + due to hardware limitation, secondary head can use only 16 and 32bpp
403 videomodes.
404 + secondary head is not accelerated.
405 + secondary head always powerups in 640x480@60-32 videomode. You have to use
406 fbset to change this mode.
407 + TV output is not supported
408 + kernel is not fully multihead ready, so some things are impossible to do.
409 + if you compiled it as module, you must insert matroxfb_g450 and matroxfb_crtc2
410 into kernel.
411
412 --
413 Petr Vandrovec <vandrove@vc.cvut.cz>