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authorÁlvaro Fernández Rojas <noltari@gmail.com>2016-09-10 14:54:26 +0200
committerÁlvaro Fernández Rojas <noltari@gmail.com>2016-09-10 14:54:26 +0200
commit2b1c6b21b5e6c82ebb55d7fb7df90e60e88cbb14 (patch)
treeba6d48b4fec219d07110f5d55afc19bc309d2bdb /target/linux/brcm2708/patches-4.4/0323-Allow-up-to-24dB-digital-gain-to-be-applied-when-usi.patch
parentac08cb06f6734ebf73ed855cbc836c566f80eaca (diff)
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brcm2708: update linux 4.4 patches to latest version
As usual these patches were extracted and rebased from the raspberry pi repo: https://github.com/raspberrypi/linux/tree/rpi-4.4.y Also adds support for Raspberry Pi Compute Module 3 (untested). Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0323-Allow-up-to-24dB-digital-gain-to-be-applied-when-usi.patch')
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diff --git a/target/linux/brcm2708/patches-4.4/0323-Allow-up-to-24dB-digital-gain-to-be-applied-when-usi.patch b/target/linux/brcm2708/patches-4.4/0323-Allow-up-to-24dB-digital-gain-to-be-applied-when-usi.patch
new file mode 100644
index 0000000..3278745
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.4/0323-Allow-up-to-24dB-digital-gain-to-be-applied-when-usi.patch
@@ -0,0 +1,60 @@
+From 691922255a15630c6f726c4c871ce2475d4fec72 Mon Sep 17 00:00:00 2001
+From: DigitalDreamtime <clive.messer@digitaldreamtime.co.uk>
+Date: Fri, 6 May 2016 09:42:55 +0100
+Subject: [PATCH] Allow up to 24dB digital gain to be applied when using
+ IQAudIO DAC
+
+24db_digital_gain DT param can be used to specify that PCM512x
+codec "Digital" volume control should not be limited to 0dB gain,
+and if specified will allow the full 24dB gain.
+
+Signed-off-by: DigitalDreamtime <clive.messer@digitaldreamtime.co.uk>
+---
+ arch/arm/boot/dts/overlays/README | 17 +++++++++++++++--
+ arch/arm/boot/dts/overlays/iqaudio-dac-overlay.dts | 6 +++++-
+ 2 files changed, 20 insertions(+), 3 deletions(-)
+
+--- a/arch/arm/boot/dts/overlays/README
++++ b/arch/arm/boot/dts/overlays/README
+@@ -490,8 +490,21 @@ Params: <None>
+
+ Name: iqaudio-dac
+ Info: Configures the IQaudio DAC audio card
+-Load: dtoverlay=iqaudio-dac
+-Params: <None>
++Load: dtoverlay=iqaudio-dac,<param>
++Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
++ Digital volume control. Enable with
++ "dtoverlay=iqaudio-dac,24db_digital_gain"
++ (The default behaviour is that the Digital
++ volume control is limited to a maximum of
++ 0dB. ie. it can attenuate but not provide
++ gain. For most users, this will be desired
++ as it will prevent clipping. By appending
++ the 24db_digital_gain parameter, the Digital
++ volume control will allow up to 24dB of
++ gain. If this parameter is enabled, it is the
++ responsibility of the user to ensure that
++ the Digital volume control is set to a value
++ that does not result in clipping/distortion!)
+
+
+ Name: iqaudio-dacplus
+--- a/arch/arm/boot/dts/overlays/iqaudio-dac-overlay.dts
++++ b/arch/arm/boot/dts/overlays/iqaudio-dac-overlay.dts
+@@ -30,10 +30,14 @@
+
+ fragment@2 {
+ target = <&sound>;
+- __overlay__ {
++ frag2: __overlay__ {
+ compatible = "iqaudio,iqaudio-dac";
+ i2s-controller = <&i2s>;
+ status = "okay";
+ };
+ };
++
++ __overrides__ {
++ 24db_digital_gain = <&frag2>,"iqaudio,24db_digital_gain?";
++ };
+ };