drivers/firmware/arm_ffa/bus.c

Source file repositories/reference/linux-study-clean/drivers/firmware/arm_ffa/bus.c

File Facts

System
Linux kernel
Corpus path
drivers/firmware/arm_ffa/bus.c
Extension
.c
Size
5957 bytes
Lines
266
Domain
Driver Families
Bucket
drivers/firmware
Inferred role
Driver Families: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

static int ffa_device_match(struct device *dev, const struct device_driver *drv)
{
	const struct ffa_device_id *id_table;
	struct ffa_device *ffa_dev;

	id_table = to_ffa_driver(drv)->id_table;
	ffa_dev = to_ffa_dev(dev);
	if (!id_table)
		return 0;

	while (!uuid_is_null(&id_table->uuid)) {
		/*
		 * FF-A v1.0 doesn't provide discovery of UUIDs, just the
		 * partition IDs, so match it unconditionally here and handle
		 * it via the installed bus notifier during driver binding.
		 */
		if (uuid_is_null(&ffa_dev->uuid))
			return 1;

		if (uuid_equal(&ffa_dev->uuid, &id_table->uuid))
			return 1;
		id_table++;
	}

	return 0;
}

static int ffa_device_probe(struct device *dev)
{
	struct ffa_driver *ffa_drv = to_ffa_driver(dev->driver);
	struct ffa_device *ffa_dev = to_ffa_dev(dev);

	/* UUID can be still NULL with FF-A v1.0, so just skip probing them */
	if (uuid_is_null(&ffa_dev->uuid))
		return -ENODEV;

	return ffa_drv->probe(ffa_dev);
}

static void ffa_device_remove(struct device *dev)
{
	struct ffa_driver *ffa_drv = to_ffa_driver(dev->driver);

	if (ffa_drv->remove)
		ffa_drv->remove(to_ffa_dev(dev));
}

static int ffa_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
	const struct ffa_device *ffa_dev = to_ffa_dev(dev);

	return add_uevent_var(env, "MODALIAS=" FFA_UEVENT_MODALIAS_FMT,
			      ffa_dev->vm_id, &ffa_dev->uuid);
}

static ssize_t modalias_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	struct ffa_device *ffa_dev = to_ffa_dev(dev);

	return sysfs_emit(buf, FFA_UEVENT_MODALIAS_FMT, ffa_dev->vm_id,
			  &ffa_dev->uuid);
}
static DEVICE_ATTR_RO(modalias);

static ssize_t partition_id_show(struct device *dev,
				 struct device_attribute *attr, char *buf)
{
	struct ffa_device *ffa_dev = to_ffa_dev(dev);

	return sprintf(buf, "0x%04x\n", ffa_dev->vm_id);
}
static DEVICE_ATTR_RO(partition_id);

static ssize_t uuid_show(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct ffa_device *ffa_dev = to_ffa_dev(dev);

	return sprintf(buf, "%pUb\n", &ffa_dev->uuid);
}
static DEVICE_ATTR_RO(uuid);

static struct attribute *ffa_device_attributes_attrs[] = {
	&dev_attr_partition_id.attr,
	&dev_attr_uuid.attr,
	&dev_attr_modalias.attr,
	NULL,
};
ATTRIBUTE_GROUPS(ffa_device_attributes);

Annotation

Implementation Notes