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Linus Torvalds1da177e2005-04-16 15:20:36 -07001Documentation for the ESS AudioDrive chips
2
3In 2.4 kernels the SoundBlaster driver not only tries to detect an ESS chip, it
4tries to detect the type of ESS chip too. The correct detection of the chip
5doesn't always succeed however, so unless you use the kernel isapnp facilities
6(and you chip is pnp capable) the default behaviour is 2.0 behaviour which
7means: only detect ES688 and ES1688.
8
9All ESS chips now have a recording level setting. This is a need-to-have for
10people who want to use their ESS for recording sound.
11
12Every chip that's detected as a later-than-es1688 chip has a 6 bits logarithmic
13master volume control.
14
15Every chip that's detected as a ES1887 now has Full Duplex support. Made a
16little testprogram that shows that is works, haven't seen a real program that
17needs this however.
18
19For ESS chips an additional parameter "esstype" can be specified. This controls
20the (auto) detection of the ESS chips. It can have 3 kinds of values:
21
22-1 Act like 2.0 kernels: only detect ES688 or ES1688.
230 Try to auto-detect the chip (may fail for ES1688)
24688 The chip will be treated as ES688
251688 ,, ,, ,, ,, ,, ,, ES1688
261868 ,, ,, ,, ,, ,, ,, ES1868
271869 ,, ,, ,, ,, ,, ,, ES1869
281788 ,, ,, ,, ,, ,, ,, ES1788
291887 ,, ,, ,, ,, ,, ,, ES1887
301888 ,, ,, ,, ,, ,, ,, ES1888
31
32Because Full Duplex is supported for ES1887 you can specify a second DMA
33channel by specifying module parameter dma16. It can be one of: 0, 1, 3 or 5.
34