devm_request_resource — request and reserve an I/O or memory resource
| int devm_request_resource ( | struct device * dev, | 
| struct resource * root, | |
| struct resource * new ); | 
devdevice for which to request the resource
rootroot of the resource tree from which to request the resource
newdescriptor of the resource to request
   This is a device-managed version of request_resource. There is usually
   no need to release resources requested by this function explicitly since
   that will be taken care of when the device is unbound from its driver.
   If for some reason the resource needs to be released explicitly, because
   of ordering issues for example, drivers must call devm_release_resource
   rather than the regular release_resource.
   
When a conflict is detected between any existing resources and the newly requested resource, an error message will be printed.
Returns 0 on success or a negative error code on failure.