drivers/accel/drm_accel.c

Source file repositories/reference/linux-study-clean/drivers/accel/drm_accel.c

File Facts

System
Linux kernel
Corpus path
drivers/accel/drm_accel.c
Extension
.c
Size
4814 bytes
Lines
209
Domain
Driver Families
Bucket
drivers/accel
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

const struct file_operations *new_fops;
	struct drm_minor *minor;
	int err;

	minor = drm_minor_acquire(&accel_minors_xa, iminor(inode));
	if (IS_ERR(minor))
		return PTR_ERR(minor);

	new_fops = fops_get(minor->dev->driver->fops);
	if (!new_fops) {
		err = -ENODEV;
		goto out;
	}

	replace_fops(filp, new_fops);
	if (filp->f_op->open)
		err = filp->f_op->open(inode, filp);
	else
		err = 0;

out:
	drm_minor_release(minor);

	return err;
}

static const struct file_operations accel_stub_fops = {
	.owner = THIS_MODULE,
	.open = accel_stub_open,
	.llseek = noop_llseek,
};

void accel_core_exit(void)
{
	unregister_chrdev(ACCEL_MAJOR, "accel");
	accel_sysfs_destroy();
	WARN_ON(!xa_empty(&accel_minors_xa));
}

int __init accel_core_init(void)
{
	int ret;

	ret = accel_sysfs_init();
	if (ret < 0) {
		DRM_ERROR("Cannot create ACCEL class: %d\n", ret);
		goto error;
	}

	ret = register_chrdev(ACCEL_MAJOR, "accel", &accel_stub_fops);
	if (ret < 0)
		DRM_ERROR("Cannot register ACCEL major: %d\n", ret);

error:
	/*
	 * Any cleanup due to errors will be done in drm_core_exit() that
	 * will call accel_core_exit()
	 */
	return ret;
}

Annotation

Implementation Notes