lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <20240418105730.120913-1-andrejs.cainikovs@gmail.com>
Date: Thu, 18 Apr 2024 12:57:30 +0200
From: Andrejs Cainikovs <andrejs.cainikovs@...il.com>
To: Nishanth Menon <nm@...com>,
	Vignesh Raghavendra <vigneshr@...com>,
	Tero Kristo <kristo@...nel.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
	Conor Dooley <conor+dt@...nel.org>
Cc: Andrejs Cainikovs <andrejs.cainikovs@...adex.com>,
	linux-arm-kernel@...ts.infradead.org,
	devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH v1] arm64: dts: k3-am625-verdin: enable nau8822 pll

From: Andrejs Cainikovs <andrejs.cainikovs@...adex.com>

In current configuration, nau8822 codec on development carrier board
provides distorted audio output. This happens due to reference clock
is fixed to 25MHz and no PLL is enabled. Following is the calculation
of deviation error for different frequencies:

44100Hz:

fs = 256 (fixed)
prescaler = 2
target frequency = 44100 * 256 * 2 = 22579200
deviation = 22579200 vs 25000000 = 9.6832%

48000Hz:

fs = 256 (fixed)
prescaler = 2
target frequency = 48000 * 256 * 2 = 24576000
deviation = 24576000 vs 25000000 = 1.696%

Enabling nau822 PLL via providing mclk-fs property to simple-audio-card
configures clocks properly, but also adjusts audio reference clock
(mclk), which in case of TI AM62 should be avoided, as it only
supports 25MHz output [1][2].

This change enables PLL on nau8822 by providing mclk-fs, and moves
away audio reference clock from DAI configuration, which prevents
simple-audio-card to adjust it before every playback [3].

[1]: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1175479/processor-sdk-am62x-output-audio_ext_refclk0-as-mclk-for-codec-and-mcbsp/4444986#4444986
[2]: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1188051/am625-audio_ext_refclk1-clock-output---dts-support/4476322#4476322
[3]: sound/soc/generic/simple-card-utils.c#L441

Signed-off-by: Andrejs Cainikovs <andrejs.cainikovs@...adex.com>
---
This patch requires https://lore.kernel.org/all/20240409121719.337709-1-andrejs.cainikovs@gmail.com/ to be applied,
if not the audio will just stop working because no code will ever enable the required clock to the codec.
---
 arch/arm64/boot/dts/ti/k3-am62-verdin-dev.dtsi | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/ti/k3-am62-verdin-dev.dtsi b/arch/arm64/boot/dts/ti/k3-am62-verdin-dev.dtsi
index 74eec1a1abca..5c1284b802ad 100644
--- a/arch/arm64/boot/dts/ti/k3-am62-verdin-dev.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am62-verdin-dev.dtsi
@@ -14,6 +14,7 @@ sound {
 		simple-audio-card,bitclock-master = <&codec_dai>;
 		simple-audio-card,format = "i2s";
 		simple-audio-card,frame-master = <&codec_dai>;
+		simple-audio-card,mclk-fs = <256>;
 		simple-audio-card,name = "verdin-nau8822";
 		simple-audio-card,routing =
 			"Headphones", "LHP",
@@ -34,7 +35,6 @@ sound {
 			"Line", "Line In";
 
 		codec_dai: simple-audio-card,codec {
-			clocks = <&audio_refclk1>;
 			sound-dai = <&nau8822_1a>;
 		};
 
@@ -107,6 +107,8 @@ nau8822_1a: audio-codec@1a {
 		reg = <0x1a>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&pinctrl_i2s1_mclk>;
+		clock-names = "mclk";
+		clocks = <&audio_refclk1>;
 		#sound-dai-cells = <0>;
 	};
 
-- 
2.34.1


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ