From 4d526df7ac7132afe91292f3821ae46853fa9984 Mon Sep 17 00:00:00 2001
From: Amaury Pouly <amaury.pouly@gmail.com>
Date: Sun, 21 Aug 2016 20:31:55 +0100
Subject: wm8975: document audiohw settings

Change-Id: I0456f85e4ebc821c23e25026fbee3d8cf7526ee7
---
 firmware/drivers/audio/wm8975.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'firmware/drivers/audio/wm8975.c')

diff --git a/firmware/drivers/audio/wm8975.c b/firmware/drivers/audio/wm8975.c
index 88be2cf5ce..a1af1331f2 100644
--- a/firmware/drivers/audio/wm8975.c
+++ b/firmware/drivers/audio/wm8975.c
@@ -296,6 +296,8 @@ void audiohw_disable_recording(void)
     wm8975_write(PWRMGMT1, wm8975_regs[PWRMGMT1]);
 }
 
+/* volume in 0 .. 63, corresponds to -17.25dB .. 30dB in steps of 0.75dB
+ * microphone has an extra 20dB boost so 0 .. 63 corresponds to 2.75dB .. 50dB */
 void audiohw_set_recvol(int left, int right, int type)
 {
     switch (type)
-- 
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