You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
100 lines
3.5 KiB
Diff
100 lines
3.5 KiB
Diff
From 796cd923dec66639357bf711ae5758d86e8cd3f3 Mon Sep 17 00:00:00 2001
|
|
From: Digital Dreamtime <clive.messer@digitaldreamtime.co.uk>
|
|
Date: Thu, 4 Feb 2016 14:14:44 +0000
|
|
Subject: [PATCH 140/304] 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.
|
|
---
|
|
arch/arm/boot/dts/overlays/README | 17 +++++++++++++++--
|
|
.../boot/dts/overlays/iqaudio-dacplus-overlay.dts | 6 +++++-
|
|
sound/soc/bcm/iqaudio-dac.c | 20 ++++++++++++++------
|
|
3 files changed, 34 insertions(+), 9 deletions(-)
|
|
|
|
--- a/arch/arm/boot/dts/overlays/README
|
|
+++ b/arch/arm/boot/dts/overlays/README
|
|
@@ -362,8 +362,21 @@ Params: <None>
|
|
|
|
Name: iqaudio-dacplus
|
|
Info: Configures the IQaudio DAC+ audio card
|
|
-Load: dtoverlay=iqaudio-dacplus
|
|
-Params: <None>
|
|
+Load: dtoverlay=iqaudio-dacplus,<param>=<val>
|
|
+Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
|
|
+ Digital volume control. Enable with
|
|
+ "dtoverlay=iqaudio-dacplus,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: lirc-rpi
|
|
--- a/arch/arm/boot/dts/overlays/iqaudio-dacplus-overlay.dts
|
|
+++ b/arch/arm/boot/dts/overlays/iqaudio-dacplus-overlay.dts
|
|
@@ -7,7 +7,7 @@
|
|
|
|
fragment@0 {
|
|
target = <&sound>;
|
|
- __overlay__ {
|
|
+ frag0: __overlay__ {
|
|
compatible = "iqaudio,iqaudio-dac";
|
|
i2s-controller = <&i2s>;
|
|
status = "okay";
|
|
@@ -36,4 +36,8 @@
|
|
};
|
|
};
|
|
};
|
|
+
|
|
+ __overrides__ {
|
|
+ 24db_digital_gain = <&frag0>,"iqaudio,24db_digital_gain?";
|
|
+ };
|
|
};
|
|
--- a/sound/soc/bcm/iqaudio-dac.c
|
|
+++ b/sound/soc/bcm/iqaudio-dac.c
|
|
@@ -23,14 +23,19 @@
|
|
#include <sound/soc.h>
|
|
#include <sound/jack.h>
|
|
|
|
+static bool digital_gain_0db_limit = true;
|
|
+
|
|
static int snd_rpi_iqaudio_dac_init(struct snd_soc_pcm_runtime *rtd)
|
|
{
|
|
- int ret;
|
|
- struct snd_soc_card *card = rtd->card;
|
|
-
|
|
- ret = snd_soc_limit_volume(card, "Digital Playback Volume", 207);
|
|
- if (ret < 0)
|
|
- dev_warn(card->dev, "Failed to set volume limit: %d\n", ret);
|
|
+ if (digital_gain_0db_limit)
|
|
+ {
|
|
+ int ret;
|
|
+ struct snd_soc_card *card = rtd->card;
|
|
+
|
|
+ ret = snd_soc_limit_volume(card, "Digital Playback Volume", 207);
|
|
+ if (ret < 0)
|
|
+ dev_warn(card->dev, "Failed to set volume limit: %d\n", ret);
|
|
+ }
|
|
|
|
return 0;
|
|
}
|
|
@@ -94,6 +99,9 @@ static int snd_rpi_iqaudio_dac_probe(str
|
|
dai->platform_name = NULL;
|
|
dai->platform_of_node = i2s_node;
|
|
}
|
|
+
|
|
+ digital_gain_0db_limit = !of_property_read_bool(pdev->dev.of_node,
|
|
+ "iqaudio,24db_digital_gain");
|
|
}
|
|
|
|
ret = snd_soc_register_card(&snd_rpi_iqaudio_dac);
|