Re: [PATCH v5 1/3] device property: Introduce fwnode_get_name()

From: Rob Herring
Date: Fri Dec 07 2018 - 12:24:32 EST


On Wed, Nov 28, 2018 at 02:59:50PM +0300, Heikki Krogerus wrote:
> This helper returns the name of the node. The name is
> primarily expected to be returned from a new fwnode
> operation meant for this purpose, but when no name is
> returned, the helper will also attempt to read a device
> property "name".
>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/base/property.c | 36 ++++++++++++++++++++++++++++++++++++
> include/linux/fwnode.h | 3 +++
> include/linux/property.h | 2 ++
> 3 files changed, 41 insertions(+)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index 240ab5230ff6..8bd35b44d9ec 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -1156,6 +1156,42 @@ void fwnode_handle_put(struct fwnode_handle *fwnode)
> }
> EXPORT_SYMBOL_GPL(fwnode_handle_put);
>
> +/**
> + * fwnode_get_name - Copy the name of an fwnode to a buffer
> + * @fwnode: Pointer to the node
> + * @buf: Buffer where the name is copied to
> + * @len: Size of the buffer
> + *
> + * Copies the node name of @fwnode to @buf. The routine attempts to first use
> + * the get_name fwnode op of @fwnode, and if it fails, the routine attempts to
> + * read a property "name".
> + *
> + * NOTE: @buf must be large enough to accommodate the name and trailing '\0'.
> + *
> + * Returns 0 on success or errno in case of an error.
> + */
> +int fwnode_get_name(const struct fwnode_handle *fwnode, char *buf, size_t len)
> +{
> + const char *name;
> + int ret;
> +
> + ret = fwnode_call_int_op(fwnode, get_name, buf, len);
> + if (ret == 0 || ret == -EOVERFLOW)
> + return ret;
> +
> + ret = fwnode_call_int_op(fwnode, property_read_string_array,
> + "name", &name, 1);

Do you expect this to work on DT? It does today, but I plan to change
that. 'name' is a fake property on FDT.

Again, I think this is all working at too low of a level. Name is used
either for matching or an informational string. For matching, this
should remain firmware specific. For imformational strings,
device_node.full_name works.

Rob