Function devclass_add_device

freebsd/kern/subr_bus.c:1699–1723

* @internal * @brief Add a device to a devclass * * A unit number is allocated for the device (using the device's * preferred unit number if any) and the device is registered in the * devclass. This allows the device to be looked up by its unit * number, e.g. by decoding a dev_t minor number. * * @param dc the devclass to add to * @param dev the device to add * * @retval 0 success *

 * @retval ENOMEM	memory allocation failure
 */
static int
devclass_add_device(devclass_t dc, device_t dev)
{
	int buflen, error;

	PDEBUG(("%s in devclass %s", DEVICENAME(dev), DEVCLANAME(dc)));

	buflen = snprintf(NULL, 0, "%s%d$", dc->name, INT_MAX);
	if (buflen < 0)
		return (ENOMEM);
	dev->nameunit = malloc(buflen, M_BUS, M_NOWAIT|M_ZERO);
	if (!dev->nameunit)
		return (ENOMEM);

	if ((error = devclass_alloc_unit(dc, dev, &dev->unit)) != 0) {
		free(dev->nameunit, M_BUS);
		dev->nameunit = NULL;
		return (error);
	}
	dc->devices[dev->unit] = dev;
	dev->devclass = dc;
	snprintf(dev->nameunit, buflen, "%s%d", dc->name, dev->unit);

	return (0);
}

/**
 * @internal