The HP Elitepad 1000 G2 tablet has 2 headset jacks:
1. on the dock which uses the output of the codecs built-in HP-amp + the standard IN2 input which is always used with the headset-jack.
2. on the tablet itself, this uses the line-out of the codec + an external HP-amp, which gets enabled by the ALC5642 codec's GPIO1 pin; and IN1 for the headset-mic.
The codec's GPIO1 is also its only IRQ output pin, so this means that the codec's IRQ cannot be used on this tablet. Instead the jack-detect is connected directly to GPIOs on the main SoC. The dock has a helper chip which also detects if a headset-mic is present or not, so there are 2 GPIOs for the jack-detect status of the dock. The tablet jack uses a single GPIO which indicates if a jack is present or not.
Differentiating between between headphones vs a headset on the tablet jack is done by using the usual mic-bias over-current-detection mechanism.
Regards,
Hans
Hans de Goede (5): ASoC: rt5640: Move rt5640_disable_jack_detect() up in the rt5640.c file ASoC: rt5640: Delay requesting IRQ until the machine-drv calls set_jack ASoC: rt5640: Add optional hp_det_gpio parameter to rt5640_detect_headset() ASoC: rt5640: Add rt5640_set_ovcd_params() helper ASoC: Intel: bytcr_rt5640: Add support for HP Elite Pad 1000G2 jack-detect
sound/soc/codecs/rt5640.c | 133 ++++++++++++----------- sound/soc/codecs/rt5640.h | 6 ++ sound/soc/intel/boards/bytcr_rt5640.c | 146 +++++++++++++++++++++++++- 3 files changed, 225 insertions(+), 60 deletions(-)