Subject: Re: Is sbdsp.c misusing bus_space_write_1?
To: John F. Woods <jfw@funhouse.com>
From: Jason Thorpe <thorpej@nas.nasa.gov>
List: current-users
Date: 07/03/1998 09:16:29
On Fri, 3 Jul 1998 08:05:51 -0400 (EDT)
"John F. Woods" <jfw@funhouse.com> wrote:
> In studying the soundblaster driver (to figure out how to write a proper
> ProAudio Spectrum driver), I noticed that sbdsp.c has the following
> code:
>
> if (bus_space_map(iot, JAZZ16_CONFIG_PORT, 1, 0, &ioh)) {
> ...
> }
> bus_space_write_1(iot, ioh, 0, JAZZ16_WAKEUP);
> delay(10000); /* delay 10 ms */
> bus_space_write_1(iot, ioh, 0, JAZZ16_SETBASE);
> bus_space_write_1(iot, ioh, 0, sc->sc_iobase & 0x70);
>
> Now, does bus_space_map create a mapping which you apply local offsets
> to, or does it simply validate certain regions of the given mapped
> space which you still must supply correct offsets to? (In other
> words, should those 0s be JAZZ16_CONFIG_PORT?)
bus_space_map() creates a mapping which you apply local offsets to.
Those usages appear to be correct.
Jason R. Thorpe thorpej@nas.nasa.gov
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