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Fix some documentation typos

This commit is contained in:
James Cloos 2008-03-03 16:10:04 -05:00
parent 3f23139137
commit 613852ce6a
1 changed files with 8 additions and 8 deletions
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16
hw/xfree86/ddc/DDC.HOWTO
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@ -6,24 +6,24 @@
When implementing DDC in the driver one has the choice between When implementing DDC in the driver one has the choice between
DDC1 and DDC2. DDC1 and DDC2.
DDC1 data is contiuously transmitted by a DDC1 capable display DDC1 data is continuously transmitted by a DDC1 capable display
device. The data is send serially over a data line; the Vsync device. The data is send serially over a data line; the Vsync
signal serves as clock. Only one EDID 1.x data block can be signal serves as clock. Only one EDID 1.x data block can be
transmitted using DDC1. Since transmission of an EDID1 block transmitted using DDC1. Since transmission of an EDID1 block
using a regular Vsync frequency would take up several seconds using a regular Vsync frequency would take up several seconds
the driver can increase the Vsync frequency to up to 25 kHz as the driver can increase the Vsync frequency to up to 25 kHz as
soon as it detects DDC1 activety on the data line. soon as it detects DDC1 activity on the data line.
DDC2 data is transmitted using the I2C protocol. This requires DDC2 data is transmitted using the I2C protocol. This requires
an additional clock line. DDC2 is capable of transmitting EDID1 an additional clock line. DDC2 is capable of transmitting EDID1
and EDID2 block as well as a VDIF block on display devices that and EDID2 block as well as a VDIF block on display devices that
support these. support these.
Display devices switch into the DDC2 mode as soon as they detect Display devices switch into the DDC2 mode as soon as they detect
activety on the DDC clock line. Once the are in DDC2 mode they activity on the DDC clock line. Once the are in DDC2 mode they
stop transmitting DDC1 signals until the next power cycle. stop transmitting DDC1 signals until the next power cycle.
Some graphics chipset configurations which are not capable of Some graphics chipset configurations which are not capable of
DDC2 might still be able to read DDC1 data. Where available DDC2 might still be able to read DDC1 data. Where available
DDC2 it is preferrable. DDC2 it is preferable.
All relevant prototypes and defines are in xf86DDC.h. All relevant prototypes and defines are in xf86DDC.h.
DDC2 additionally requires I2C support. The I2C prototypes DDC2 additionally requires I2C support. The I2C prototypes
@ -37,7 +37,7 @@
unsigned int XXX_ddc1Read(ScrnInfoPtr pScrn) unsigned int XXX_ddc1Read(ScrnInfoPtr pScrn)
Additionally a function is required to inclrease the Vsync Additionally a function is required to increase the Vsync
frequency to max. 25 kHz. frequency to max. 25 kHz.
void XXX_ddc1SetSpeed(ScrnInfoPtr pScrn, xf86ddcSpeed speed) void XXX_ddc1SetSpeed(ScrnInfoPtr pScrn, xf86ddcSpeed speed)
@ -58,7 +58,7 @@
in PreInit(). DDC1SetSpeed is a pointer to the SetSpeed() in PreInit(). DDC1SetSpeed is a pointer to the SetSpeed()
function, DDC1Read has to point to the DDC1 read function. function, DDC1Read has to point to the DDC1 read function.
The function will return a pointer to the xf86Monitor structure The function will return a pointer to the xf86Monitor structure
which contains all information retreived by DDC. which contains all information retrieved by DDC.
NULL will be returned on failure. NULL will be returned on failure.
DDC2 Support DDC2 Support
@ -73,7 +73,7 @@
to the I2CBusRec of the appropriate I2C Bus has to be passed to the I2CBusRec of the appropriate I2C Bus has to be passed
as the second argument. as the second argument.
The function will return a pointer to the xf86Monitor structure The function will return a pointer to the xf86Monitor structure
which contains all information retreived by DDC. which contains all information retrieved by DDC.
NULL will be returned on failure. NULL will be returned on failure.
Printing monitor parameters Printing monitor parameters
@ -86,7 +86,7 @@
is provided. is provided.
Further processing of the xf86Monitor structure is not yet Further processing of the xf86Monitor structure is not yet
implemented. Howerver it is planned to use the information implemented. However, it is planned to use the information
about video modes, gamma values etc. about video modes, gamma values etc.
Therefore it is strongly recommended to read out DDC data Therefore it is strongly recommended to read out DDC data
before any video mode processing is done. before any video mode processing is done.