Hi Laurent,
Thanks for reviewing.
On Tue, Dec 15, 2020 at 07:00:28PM +0200, Laurent Pinchart wrote:
> Hi Calvin,
>
> Thank you for the patch.
>
> On Tue, Dec 15, 2020 at 10:13:11PM +0530, Calvin Johnson wrote:
> > Using fwnode_get_id(), get the reg property value for DT node
> > and get the _ADR object value for ACPI node.
> >
> > Signed-off-by: Calvin Johnson <calvin.johnson@xxxxxxxxxxx>
> > ---
> >
> > Changes in v2: None
> >
> > drivers/base/property.c | 26 ++++++++++++++++++++++++++
> > include/linux/property.h | 1 +
> > 2 files changed, 27 insertions(+)
> >
> > diff --git a/drivers/base/property.c b/drivers/base/property.c
> > index 4c43d30145c6..1c50e17ae879 100644
> > --- a/drivers/base/property.c
> > +++ b/drivers/base/property.c
> > @@ -580,6 +580,32 @@ const char *fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
> > return fwnode_call_ptr_op(fwnode, get_name_prefix);
> > }
> >
> > +/**
> > + * fwnode_get_id - Get the id of a fwnode.
> > + * @fwnode: firmware node
> > + * @id: id of the fwnode
> > + *
>
> Is the concept of fwnode ID documented clearly somewhere ? I think this
> function should otherwise have more documentation, at least to explain
> what the ID is.
Agree. Will add more info here.
>
> > + * Returns 0 on success or a negative errno.
> > + */
> > +int fwnode_get_id(struct fwnode_handle *fwnode, u32 *id)
> > +{
> > + unsigned long long adr;
> > + acpi_status status;
> > +
> > + if (is_of_node(fwnode)) {
> > + return of_property_read_u32(to_of_node(fwnode), "reg", id);
> > + } else if (is_acpi_node(fwnode)) {
> > + status = acpi_evaluate_integer(ACPI_HANDLE_FWNODE(fwnode),
> > + METHOD_NAME__ADR, NULL, &adr);
> > + if (ACPI_FAILURE(status))
> > + return -ENODATA;
>
> Would it make sense to standardize error codes ? of_property_read_u32()
> can return -EINVAL, -ENODATA or -EOVERFLOW. I don't think the caller of
> this function would be very interested to tell those three cases apart.
> Maybe we should return -EINVAL in all error cases ? Or maybe different
> error codes to mean "the backend doesn't support the concept of IDs",
> and "the device doesn't have an ID" ?
I think it make sense to return just -EINVAL. Will take care in v3.
Thanks
Calvin
