On Thu, Sep 10, 2015 at 09:24:20AM +0100, Charles Keepax wrote:
On Thu, Sep 10, 2015 at 09:15:32AM +0800, Zidan Wang wrote:
+static const DECLARE_TLV_DB_SCALE(adc_tlv, -9750, 50, 1); +static const DECLARE_TLV_DB_SCALE(dac_tlv, -12750, 50, 1);
I think the min register value will corresponding to the min gain. So value 0 will also have a gain value, although it's for digital mute.
Refer to wm8962 codec driver, beep gain range is -90db~-6db, step in 6db, but it define the beep gain like below: static const DECLARE_TLV_DB_SCALE(beep_tlv, -9600, 600, 1);
I might have to defer to Mark on this one then, if it is normal to just use an additional gain value for mute in this type of situation then it is ok with me. But it doesn't seem like that would be a sensible thing, as you are asking for -97.5dB but that is not what you are getting which doesn't seem like the nicest interface.
The last value in the scale macro is a flag saying if the minimum value is mute - if it's set to 1 userspace should know this is what's going on.