From: Patrick Bruenn p.bruenn@beckhoff.com
main usecase in mind are LEDs which indicate a state like "power on". With this patchset applied, all you have to do is: Add a gpio-led node with 'default-state = "on";' property to your device tree. And the LED will automatically light up during U-Boot startup.
Changes in v4: - don't break 'make tests' - gpio_a pin 4 is already use by dm_test_gpio_phandles() -> we switch to use pin 5 and 6 - adjust dm_test_led_base() to the fact that we have two more LEDs, now - rebased on 2600df4f8ef12ece9cec13030005919e0ba2b0d5 (master 2018-04-09)
Changes in v3: - use ofnode_read_bool() instead of ofnode_read_string() to determine if LED node has the default-state property
Changes in v2: - rebase to v2018.05-rc1 - add dm_test_led_default_state() to tests/dm/led.c
Patrick Bruenn (3): dm: led: Support "default-state" property dm: led: auto probe() LEDs with "default-state" dm: led: add testcase for "default-state" property
arch/sandbox/dts/test.dts | 12 ++++++++++++ drivers/led/led_gpio.c | 25 ++++++++++++++++++++++++- test/dm/led.c | 20 +++++++++++++++++++- 3 files changed, 55 insertions(+), 2 deletions(-)