Bus Driver probe and attach device

[Yuka Muromachi]

It mean I have 2 way to do it? (please view the code below)

CodecPresent = az_rw(sc, AZX_REG_STATESTS);
for (idx=0; idx<AZX_MAX_CODECS; idx++)
{
    if ((CodecPresent >> idx) & 0x0001)
    {
        // alloc codec info
        // fill codec info
        device_t codec_dev = device_add_child(azbus_dev, NULL, -1);
        device_set_ivars(codec_dev, codec);
        
        // I can probe and attach new device self here.        
        device_probe_and_attach(codec_dev);
    }
}

// Or, I can probe and attach all new child here
bus_generic_attach(azbus_dev);


05/07/22 に takawata at jp.freebsd.org<takawata at jp.freebsd.org> さんは書きました:
> In message <c5c2798005072123385249195e at mail.gmail.com>, 室町優香 wrote:
> >Hi:
> >
> >I'm trying to written Azalia (HD Audio) driver for freebsd now.
> >
> >The HDA controller is a standard controller, which can take max=
> >15 codecs. I'm planning made it be a bus driver (azalia bus).
> >
> >I tried to read the PCI, USB and Firewire driver code be sample.
> >It looks:
> >
> >1. Detect codec which already connected to azalia controller.
> >2. call device_add_child(azbus_dev, NULL, -1); to create a child
> >    device, which attach to azalia bus driver.
> >3. allocate memory to put codec info (e.g. device id, vendor id,=20
> >    revision..etc), and call device_set_ivars(codec_dev, codec_info);
> >    save the codec_info ptr into device's ivars.
> >4. Continue 1 ~ 3, untin all available codecs be added.
> >
> >After all codecs be added, I call the device_probe_and_attach(azbus_dev);,
> >but there is no thing happend.=20
> 
> Because it trys to attach azbus driver itself, not try to attach its child.
> 
> >Then I try to call bus_generic_attach(azbus_dev);, the codecs driver probe
> >function be called.
> 
> >Is this correct (use bus_generic_attach()), and I'm interested the detail.
> 
> Correct. It calls device_probe_and_attach() for all child you already
> add.
> 
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