RFC Align and document return values of phandle and reference parsing for OF and ACPI

Hi everyone,

I recently came across a difference in behaviour of OF phandle parsing and ACPI reference parsing, both of which can soon be accessed using fwnode_property_get_reference_args.

The main change in this proposal touches OF, and specifically the change is about using -ENODATA to tell that the phandle reference list entry that was accessed does not exist. -ENOENT was used previously, but the same error code was also used to tell that a phandle was empty, making it impossible for the caller to figure out which of the two was the case.

I'm sending the set as RFC. In my limited testing I have found no ill effects.

These patches are on top of linux-next.

Comments on the approach and the changes themselves would be most welcome.

For what it's worth, fwnode_property_get_reference_args is in Rafael's tree (as well as in linux-next) and hasn't reached mainline yet. It will be used in the near future for parsing references to external devices in the V4L2 framework.

These patches can be found here:

<URL:https://git.linuxtv.org/sailus/media_tree.git/log/?h=fwnode-parse>

Regards,

- Sakari

Sakari Ailus (5):
clk: Increment assigned-clocks index for empty phandles
of: Return -ENODATA on accessing out of bounds indices in phandle
parsing
of: Return total number of entries in of_count_phandle_with_args
ACPI: align acpi_fwnode_get_reference_args with OF counterpart device property: Document fwnode_property_get_reference_args better

 drivers/acpi/property.c              |  3 +++
 drivers/base/power/domain.c          |  2 +-
 drivers/base/property.c              |  5 +++++
 drivers/clk/clk-conf.c               |  8 +++++---
 drivers/clk/clkdev.c                 |  2 +-
 drivers/gpio/gpiolib-of.c            |  2 +-
 drivers/gpio/gpiolib.c               |  2 +-
 drivers/gpu/host1x/mipi.c            |  2 +-
 drivers/hwspinlock/hwspinlock_core.c |  2 +-
 drivers/iio/inkern.c                 |  2 +-
 drivers/of/base.c                    | 37 ++++++++++++++++++++++++------------
 drivers/pwm/core.c                   |  2 +-
 drivers/regulator/gpio-regulator.c   |  2 +-
 drivers/reset/core.c                 |  3 ++-
 drivers/spi/spi.c                    |  2 +-
 15 files changed, 50 insertions(+), 26 deletions(-)

2.11.0