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</p><div class="example"><a id="id2739496"></a><p class="title"><b>Example 7.1. Example of AC97 Interface</b></p><div class="example-contents"><pre class="programlisting">
struct mychip {
....
struct snd_ac97 *ac97;
....
};
static unsigned short snd_mychip_ac97_read(struct snd_ac97 *ac97,
unsigned short reg)
{
struct mychip *chip = ac97->private_data;
....
/* read a register value here from the codec */
return the_register_value;
}
static void snd_mychip_ac97_write(struct snd_ac97 *ac97,
unsigned short reg, unsigned short val)
{
struct mychip *chip = ac97->private_data;
....
/* write the given register value to the codec */
}
static int snd_mychip_ac97(struct mychip *chip)
{
struct snd_ac97_bus *bus;
struct snd_ac97_template ac97;
int err;
static struct snd_ac97_bus_ops ops = {
.write = snd_mychip_ac97_write,
.read = snd_mychip_ac97_read,
};
err = snd_ac97_bus(chip->card, 0, &ops, NULL, &bus);
if (err < 0)
return err;
memset(&ac97, 0, sizeof(ac97));
ac97.private_data = chip;
return snd_ac97_mixer(bus, &ac97, &chip->ac97);
}
</pre></div></div><p><br class="example-break" />
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