VAG power control is improved to fit the manual [1]. This patch fixes as
minimum one bug: if customer muxes Headphone to Line-In right after boot,
the VAG power remains off that leads to poor sound quality from line-in.
I.e. after boot:
- Connect sound source to Line-In jack;
- Connect headphone to HP jack;
- Run following commands:
$ amixer set 'Headphone' 80%
$ amixer set 'Headphone Mux' LINE_IN
Change VAG power on/off control according to the following algorithm:
- turn VAG power ON on the 1st incoming event.
- keep it ON if there is any active VAG consumer (ADC/DAC/HP/Line-In).
- turn VAG power OFF when there is the latest consumer's pre-down event
come.
- always delay after VAG power OFF to avoid pop.
- delay after VAG power ON if the initiative consumer is Line-In, this
prevents pop during line-in muxing.
According to the data sheet [1], to avoid any pops/clicks,
the outputs should be muted during input/output
routing changes.
[1] https://www.nxp.com/docs/en/data-sheet/SGTL5000.pdf
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 9b34e6cc3bc2 ("ASoC: Add Freescale SGTL5000 codec support")
Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@xxxxxxxxxxx>
Reviewed-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
Reviewed-by: Fabio Estevam <festevam@xxxxxxxxx>
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Changes in v6:
- Code optimization