[PATCH v4 0/2] gpio: Add a managed API

[Pratyush Yadav]

Hi,

This is a re-submission of Jean-Jacques' earlier work in October last
year. It can be found at [0]. The goal is to facilitate porting drivers
from the Linux kernel. Most of the series will be about adding managed
APIs to existing infrastructure (GPIO, reset, regmap).

This particular series is about GPIOs. It adds a managed API using the
API as Linux. To make it 100% compatible with linux, there is a small
deviation from u-boot's way of naming the gpio lists: the managed
equivalent of gpio_request_by_name(..,"blabla-gpios", ...) is
devm_gpiod_get_index(..., "blabla", ...)

Travis CI run: https://travis-ci.org/github/prati0100/uboot/builds/725044296

Changes in v4:
- Rebase on latest master and fix merge conflicts.
- Move "another-test" node down the order to make sure
  dm_test_fdt_uclass_seq() continues to work.
- Bump num_devices to 9 in dm_test_bus_children(), dm_test_fdt(), and
  dm_test_uclass_foreach() to fix broken tests.
- s/DM_TESTF/UT_TESTF/g

Changes in v3:
- Add a blank line before return in devm_gpiod_get_index().
- Add Simon's Reviwed-by in both patches.

Changes in v2:
- The original series had a patch that checked for NULL pointers in the
  core GPIO functions. The checks were needed because of the addition of
  devm_gpiod_get_index_optional() which would return NULL when when no
  GPIO was assigned to the requested function. This is convenient for
  drivers that need to handle optional GPIOs.

  Simon argued that those should be behind a Kconfig option because of
  code size concerns. He also argued against implicit return in the
  macro that checked for the optional GPIOs.

  This submission removes the controversial patch so that base
  functionality can get merged.

  We still need to take a stance on who is responsible for the NULL
  check: the driver or the GPIO core? Do we want to trust drivers to
  take care of the NULL checks, or do we want to distrust them and make
  sure they don't send us anything bogus in the GPIO core. I will send a
  separate RFC of the NULL check patch and we can probably discuss the
  issue there.

[0] https://patchwork.ozlabs.org/project/uboot/cover/20191001115130.18886-1-jjhiblot@ti.com/

Jean-Jacques Hiblot (2):
  drivers: gpio: Add a managed API to get a GPIO from the device-tree
  test: gpio: Add tests for the managed API

 arch/sandbox/dts/test.dts  |  10 ++++
 drivers/gpio/gpio-uclass.c |  71 ++++++++++++++++++++++++++
 include/asm-generic/gpio.h |  47 +++++++++++++++++
 test/dm/bus.c              |   2 +-
 test/dm/gpio.c             | 102 +++++++++++++++++++++++++++++++++++++
 test/dm/test-fdt.c         |   6 +--
 6 files changed, 234 insertions(+), 4 deletions(-)

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2.28.0