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Diffstat (limited to 'Documentation/sound/oss/Maestro')
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diff --git a/Documentation/sound/oss/Maestro b/Documentation/sound/oss/Maestro deleted file mode 100644 index 4a80eb3f8e0..00000000000 --- a/Documentation/sound/oss/Maestro +++ /dev/null @@ -1,123 +0,0 @@ - An OSS/Lite Driver for the ESS Maestro family of sound cards - - Zach Brown, December 1999 - -Driver Status and Availability ------------------------------- - -The most recent version of this driver will hopefully always be available at - http://www.zabbo.net/maestro/ - -I will try and maintain the most recent stable version of the driver -in both the stable and development kernel lines. - -ESS Maestro Chip Family ------------------------ - -There are 3 main variants of the ESS Maestro PCI sound chip. The first -is the Maestro 1. It was originally produced by Platform Tech as the -'AGOGO'. It can be recognized by Platform Tech's PCI ID 0x1285 with -0x0100 as the device ID. It was put on some sound boards and a few laptops. -ESS bought the design and cleaned it up as the Maestro 2. This starts -their marking with the ESS vendor ID 0x125D and the 'year' device IDs. -The Maestro 2 claims 0x1968 while the Maestro 2e has 0x1978. - -The various families of Maestro are mostly identical as far as this -driver is concerned. It doesn't touch the DSP parts that differ (though -it could for FM synthesis). - -Driver OSS Behavior --------------------- - -This OSS driver exports /dev/mixer and /dev/dsp to applications, which -mostly adhere to the OSS spec. This driver doesn't register itself -with /dev/sndstat, so don't expect information to appear there. - -The /dev/dsp device exported behaves almost as expected. Playback is -supported in all the various lovely formats. 8/16bit stereo/mono from -8khz to 48khz, and mmap()ing for playback behaves. Capture/recording -is limited due to oddities with the Maestro hardware. One can only -record in 16bit stereo. For recording the maestro uses non interleaved -stereo buffers so that mmap()ing the incoming data does not result in -a ring buffer of LRLR data. mmap()ing of the read buffers is therefore -disallowed until this can be cleaned up. - -/dev/mixer is an interface to the AC'97 codec on the Maestro. It is -worth noting that there are a variety of AC'97s that can be wired to -the Maestro. Which is used is entirely up to the hardware implementor. -This should only be visible to the user by the presence, or lack, of -'Bass' and 'Treble' sliders in the mixer. Not all AC'97s have them. - -The driver doesn't support MIDI or FM playback at the moment. Typically -the Maestro is wired to an MPU MIDI chip, but some hardware implementations -don't. We need to assemble a white list of hardware implementations that -have MIDI wired properly before we can claim to support it safely. - -Compiling and Installing ------------------------- - -With the drivers inclusion into the kernel, compiling and installing -is the same as most OSS/Lite modular sound drivers. Compilation -of the driver is enabled through the CONFIG_SOUND_MAESTRO variable -in the config system. - -It may be modular or statically linked. If it is modular it should be -installed with the rest of the modules for the kernel on the system. -Typically this will be in /lib/modules/ somewhere. 'alias sound maestro' -should also be added to your module configs (typically /etc/conf.modules) -if you're using modular OSS/Lite sound and want to default to using a -maestro chip. - -As this is a PCI device, the module does not need to be informed of -any IO or IRQ resources it should use, it devines these from the -system. Sometimes, on sucky PCs, the BIOS fails to allocated resources -for the maestro. This will result in a message like: - maestro: PCI subsystem reports IRQ 0, this might not be correct. -from the kernel. Should this happen the sound chip most likely will -not operate correctly. To solve this one has to dig through their BIOS -(typically entered by hitting a hot key at boot time) and figure out -what magic needs to happen so that the BIOS will reward the maestro with -an IRQ. This operation is incredibly system specific, so you're on your -own. Sometimes the magic lies in 'PNP Capable Operating System' settings. - -There are very few options to the driver. One is 'debug' which will -tell the driver to print minimal debugging information as it runs. This -can be collected with 'dmesg' or through the klogd daemon. - -The other, more interesting option, is 'dsps_order'. Typically at -install time the driver will only register one available /dev/dsp device -for its use. The 'dsps_order' module parameter allows for more devices -to be allocated, as a power of two. Up to 4 devices can be registered -( dsps_order=2 ). These devices act as fully distinct units and use -separate channels in the maestro. - -Power Management ----------------- - -As of version 0.14, this driver has a minimal understanding of PCI -Power Management. If it finds a valid power management capability -on the PCI device it will attempt to use the power management -functions of the maestro. It will only do this on Maestro 2Es and -only on machines that are known to function well. You can -force the use of power management by setting the 'use_pm' module -option to 1, or can disable it entirely by setting it to 0. - -When using power management, the driver does a few things -differently. It will keep the chip in a lower power mode -when the module is inserted but /dev/dsp is not open. This -allows the mixer to function but turns off the clocks -on other parts of the chip. When /dev/dsp is opened the chip -is brought into full power mode, and brought back down -when it is closed. It also powers down the chip entirely -when the module is removed or the machine is shutdown. This -can have nonobvious consequences. CD audio may not work -after a power managing driver is removed. Also, software that -doesn't understand power management may not be able to talk -to the powered down chip until the machine goes through a hard -reboot to bring it back. - -.. more details .. ------------------- - -drivers/sound/maestro.c contains comments that hopefully explain -the maestro implementation. |