Re: [alsa, pnp] more on opl3sa2 (fwd)

From: Adam Belay (ambx1@neo.rr.com)
Date: Wed Feb 05 2003 - 17:01:32 EST


On Mon, Feb 03, 2003 at 03:15:59PM +0100, Jaroslav Kysela wrote:
> On Thu, 30 Jan 2003, Adam Belay wrote:
>
> > Hi Jaroslav,
> >
> > How does this sound...
> >
> > What if we make pnp card services match against all pnp cards and allow more
> > than one card driver to use the same card. This can be accomplished if we detach
> > the card portion from the driver model and use driver_attach. If you feel it is
>
> The question is probably another. I know that your solution will work, but
> do we need such hack against the driver model in our code? If you work
> with cards as buses, it allows us the same model as PCI code.
>
> > necessary, we could also add an optional card id to the pnp_device_id structure.
> > As for the pnpbios, I disagree with putting it under one card. If the pnpbios
> > contains two opl3sa2 sound cards then only one will be matched and therefore it
>
> It's not true. The driver model calls probe for all instances.
>
> > is a bad idea to represent the pnpbios as a card. When ACPI is introduced, both
>
> Note that if we make card as bus, then this problem will disapear.
> The enumeration will be simple: devices on the one bus. And it's strong
> advantage over current implementation when bus == protocol.
>
> What do you think about this model:
>
> bus (PnP BIOS) -> devices
> bus (ACPI) -> devices
> bus (ISA PnP) -> bus (cards) -> devices
>

I think this model has potential but before we go that direction I'd like to hear
your reactions on another more simplistic model. I'll express it with a
hypothetical code example. This model completely drops individual card matching
and is compatible with both card users and non-card users.

static struct pnp_device_id snd_als100_pnpids[] = {
        /* ALS100 - PRO16PNP */
        {.card_id = "ALS0001" .id = "@@@0001", .driver_data = ALS100_AUDIO},
        {.card_id = "ALS0001" .id = "@X@0001", .driver_data = ALS100_MPU},
        {.card_id = "ALS0001" .id = "@H@0001", .driver_data = ALS100_OPL},
        /* ALS110 - MF1000 - Digimate 3D Sound */
        {.card_id = "ALS0110" .id = "@@@1001", .driver_data = ALS100_AUDIO},
        {.card_id = "ALS0001" .id = "@X@1001", .driver_data = ALS100_MPU},
        {.card_id = "ALS0001" .id = "@H@1001", .driver_data = ALS100_OPL},
---> snip
};

static int __init snd_card_als100_probe(struct pnp_dev * dev, struct pnp_device_id * id)
{
---> snip
        snd_card_t *card;
---> snip
        card = snd_card_find(dev->card); /* this function searches for previously
                                                 registered sound cards and binds this
                                                 device to it if it finds that it was a
                                                 member of the same pnp_card */
        if (!card) {
                if ((card = snd_card_new(index[dev], id[dev], THIS_MODULE,
                         sizeof(struct snd_card_als100))) == NULL)
                return -ENOMEM;
        }
        switch (id->driver_data) {
        case ALS100_AUDIO:
---> snip
        case ALS100_MPU:
---> snip
        case ALS100_OPL:
---> snip
etc . . .

I'm interested in your opinions on this approach.

Thanks,
Adam
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