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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/sound/oss/cs46xx | |
download | linux-stable-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz linux-stable-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 linux-stable-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'Documentation/sound/oss/cs46xx')
-rw-r--r-- | Documentation/sound/oss/cs46xx | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/Documentation/sound/oss/cs46xx b/Documentation/sound/oss/cs46xx new file mode 100644 index 000000000000..88d6cf8b39f3 --- /dev/null +++ b/Documentation/sound/oss/cs46xx @@ -0,0 +1,138 @@ + +Documentation for the Cirrus Logic/Crystal SoundFusion cs46xx/cs4280 audio +controller chips (2001/05/11) + +The cs46xx audio driver supports the DSP line of Cirrus controllers. +Specifically, the cs4610, cs4612, cs4614, cs4622, cs4624, cs4630 and the cs4280 +products. This driver uses the generic ac97_codec driver for AC97 codec +support. + + +Features: + +Full Duplex Playback/Capture supported from 8k-48k. +16Bit Signed LE & 8Bit Unsigned, with Mono or Stereo supported. + +APM/PM - 2.2.x PM is enabled and functional. APM can also +be enabled for 2.4.x by modifying the CS46XX_ACPI_SUPPORT macro +definition. + +DMA playback buffer size is configurable from 16k (defaultorder=2) up to 2Meg +(defaultorder=11). DMA capture buffer size is fixed at a single 4k page as +two 2k fragments. + +MMAP seems to work well with QuakeIII, and test XMMS plugin. + +Myth2 works, but the polling logic is not fully correct, but is functional. + +The 2.4.4-ac6 gameport code in the cs461x joystick driver has been tested +with a Microsoft Sidewinder joystick (cs461x.o and sidewinder.o). This +audio driver must be loaded prior to the joystick driver to enable the +DSP task image supporting the joystick device. + + +Limitations: + +SPDIF is currently not supported. + +Primary codec support only. No secondary codec support is implemented. + + + +NOTES: + +Hercules Game Theatre XP - the EGPIO2 pin controls the external Amp, +and has been tested. +Module parameter hercules_egpio_disable set to 1, will force a 0 to EGPIODR +to disable the external amplifier. + +VTB Santa Cruz - the GPIO7/GPIO8 on the Secondary Codec control +the external amplifier for the "back" speakers, since we do not +support the secondary codec then this external amp is not +turned on. The primary codec external amplifier is supported but +note that the AC97 EAPD bit is inverted logic (amp_voyetra()). + +DMA buffer size - there are issues with many of the Linux applications +concerning the optimal buffer size. Several applications request a +certain fragment size and number and then do not verify that the driver +has the ability to support the requested configuration. +SNDCTL_DSP_SETFRAGMENT ioctl is used to request a fragment size and +number of fragments. Some applications exit if an error is returned +on this particular ioctl. Therefore, in alignment with the other OSS audio +drivers, no error is returned when a SETFRAGs IOCTL is received, but the +values passed from the app are not used in any buffer calculation +(ossfragshift/ossmaxfrags are not used). +Use the "defaultorder=N" module parameter to change the buffer size if +you have an application that requires a specific number of fragments +or a specific buffer size (see below). + +Debug Interface +--------------- +There is an ioctl debug interface to allow runtime modification of the +debug print levels. This debug interface code can be disabled from the +compilation process with commenting the following define: +#define CSDEBUG_INTERFACE 1 +There is also a debug print methodolgy to select printf statements from +different areas of the driver. A debug print level is also used to allow +additional printfs to be active. Comment out the following line in the +driver to disable compilation of the CS_DBGOUT print statements: +#define CSDEBUG 1 + +Please see the definitions for cs_debuglevel and cs_debugmask for additional +information on the debug levels and sections. + +There is also a csdbg executable to allow runtime manipulation of these +parameters. for a copy email: twoller@crystal.cirrus.com + + + +MODULE_PARMS definitions +------------------------ +MODULE_PARM(defaultorder, "i"); +defaultorder=N +where N is a value from 1 to 12 +The buffer order determines the size of the dma buffer for the driver. +under Linux, a smaller buffer allows more responsiveness from many of the +applications (e.g. games). A larger buffer allows some of the apps (esound) +to not underrun the dma buffer as easily. As default, use 32k (order=3) +rather than 64k as some of the games work more responsively. +(2^N) * PAGE_SIZE = allocated buffer size + +MODULE_PARM(cs_debuglevel, "i"); +MODULE_PARM(cs_debugmask, "i"); +cs_debuglevel=N +cs_debugmask=0xMMMMMMMM +where N is a value from 0 (no debug printfs), to 9 (maximum) +0xMMMMMMMM is a debug mask corresponding to the CS_xxx bits (see driver source). + +MODULE_PARM(hercules_egpio_disable, "i"); +hercules_egpio_disable=N +where N is a 0 (enable egpio), or a 1 (disable egpio support) + +MODULE_PARM(initdelay, "i"); +initdelay=N +This value is used to determine the millescond delay during the initialization +code prior to powering up the PLL. On laptops this value can be used to +assist with errors on resume, mostly with IBM laptops. Basically, if the +system is booted under battery power then the mdelay()/udelay() functions fail to +properly delay the required time. Also, if the system is booted under AC power +and then the power removed, the mdelay()/udelay() functions will not delay properly. + +MODULE_PARM(powerdown, "i"); +powerdown=N +where N is 0 (disable any powerdown of the internal blocks) or 1 (enable powerdown) + + +MODULE_PARM(external_amp, "i"); +external_amp=1 +if N is set to 1, then force enabling the EAPD support in the primary AC97 codec. +override the detection logic and force the external amp bit in the AC97 0x26 register +to be reset (0). EAPD should be 0 for powerup, and 1 for powerdown. The VTB Santa Cruz +card has inverted logic, so there is a special function for these cards. + +MODULE_PARM(thinkpad, "i"); +thinkpad=1 +if N is set to 1, then force enabling the clkrun functionality. +Currently, when the part is being used, then clkrun is disabled for the entire system, +but re-enabled when the driver is released or there is no outstanding open count. + |