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.
> + * 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" ?
> + *id = (u32)adr;
> + return 0;
> + }
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(fwnode_get_id);
> +
> /**
> * fwnode_get_parent - Return parent firwmare node
> * @fwnode: Firmware whose parent is retrieved
> diff --git a/include/linux/property.h b/include/linux/property.h
> index 2d4542629d80..92d405cf2b07 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -82,6 +82,7 @@ struct fwnode_handle *fwnode_find_reference(const struct fwnode_handle *fwnode,
>
> const char *fwnode_get_name(const struct fwnode_handle *fwnode);
> const char *fwnode_get_name_prefix(const struct fwnode_handle *fwnode);
> +int fwnode_get_id(struct fwnode_handle *fwnode, u32 *id);
> struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode);
> struct fwnode_handle *fwnode_get_next_parent(
> struct fwnode_handle *fwnode);
--
Regards,
Laurent Pinchart
