platform driver

Linux v6.6: drivers/base/platform.c
Linux v6.6: drivers/base/dd.c
Linux v6.6: include/linux/platform_device.h

static int platform_match(struct device *dev, struct device_driver *drv)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct platform_driver *pdrv = to_platform_driver(drv);

	/* When driver_override is set, only bind to the matching driver */
	if (pdev->driver_override)
		return !strcmp(pdev->driver_override, drv->name);

	/* Attempt an OF style match first */
	if (of_driver_match_device(dev, drv))
		return 1;

	/* Then try ACPI style match */
	if (acpi_driver_match_device(dev, drv))
		return 1;

	/* Then try to match against the id table */
	if (pdrv->id_table)
		return platform_match_id(pdrv->id_table, pdev) != NULL;

	/* fall-back to driver name match */
	return (strcmp(pdev->name, drv->name) == 0);
}

int __init_or_module __platform_driver_probe(struct platform_driver *drv,
		int (*probe)(struct platform_device *), struct module *module)
{
	int retval;

	if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
		pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
			 drv->driver.name, __func__);
		return -EINVAL;
	}

	/*
	 * We have to run our probes synchronously because we check if
	 * we find any devices to bind to and exit with error if there
	 * are any.
	 */
	drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;

	/*
	 * Prevent driver from requesting probe deferral to avoid further
	 * futile probe attempts.
	 */
	drv->prevent_deferred_probe = true;

	/* make sure driver won't have bind/unbind attributes */
	drv->driver.suppress_bind_attrs = true;

	/* temporary section violation during probe() */
	drv->probe = probe;
	retval = __platform_driver_register(drv, module);
	if (retval)
		return retval;

	/* Force all new probes of this driver to fail */
	drv->probe = platform_probe_fail;

	/* Walk all platform devices and see if any actually bound to this driver.
	 * If not, return an error as the device should have done so by now.
	 */
	if (!bus_for_each_dev(&platform_bus_type, NULL, &drv->driver, is_bound_to_driver)) {
		retval = -ENODEV;
		platform_driver_unregister(drv);
	}

	return retval;
}

struct resource *platform_get_resource(struct platform_device *dev,
				       unsigned int type, unsigned int num)
{
	u32 i;

	for (i = 0; i < dev->num_resources; i++) {
		struct resource *r = &dev->resource[i];

		if (type == resource_type(r) && num-- == 0)
			return r;
	}
	return NULL;
}