[alsa-devel] [PATCH] ASoC: WM8962: Enable start-up and normal bias after reset in runtime resume
broonie at kernel.org
Fri Jun 14 11:59:17 CEST 2013
On Fri, Jun 14, 2013 at 04:52:20PM +0800, Nicolin Chen wrote:
> The analogue circuits in WM8962 require a mid-rail analogue reference
> voltage, VMID, which generator is enabled by STARTUP_BIAS_ENA bit,
> while VMID_BUF_ENA bit can enable buffered VMID to avoid audible pops.
> Besides, these circuits also need a bias current enabled by BIAS_ENA.
> Then set VMID_SEL to 2x5k divider, the fast start-up mode, to power it
> up. And let set_bias_level() handle its 2x250k for low power standby
> and 2x50k for normal operation.
> This patch might be kinda reverting operation against commit 52c0eee3
> but after testing with WM8962 CODEC, these configurations during power
> up should be essential and soc-core would not do any of them. So the
> codec drvier need to handle it.
The biases should be being managed using set_bias_level() which will get
called automatically when audio is being started and stopped.
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