I have a production agriculture display system using a TLV320AIC3120 for sound output to a speaker built into the monitor. The primary processor is an NXP IMX6 Dual Plus. The system has an internal battery backup but not all voltage rails are backed by the battery. In particular SPKVDD the 5V rail to the TLV320AIC3120 is not backed up. The rest of the voltage rails to this device are backed by battery. After a power glitch we do not emit sound. Using dynamic debug and adding some additional messages to the log It appears the driver is working the same both before and after the power glitch. We developed this a few years ago using the Freescale/NXP (fsl) eureka-tlv320 (with slight modifications for the tlv320aic31xx) and tlv320aic31xx.c drivers.
As an experiment i compiled both the eukrea-tlv320 and the tlv320aic31xx drivers as modules. This worked as expected before the glitch. After a glitch if I manually remove the modules and re-insert them sound can be restored.
We have a user space application that can detect the power loss and if the loss is persistent will gracefully shutdown the system. When power is restored we would like to use this to tell the driver to perform some kind of restorative action. I have tried triggering through sysfs various resets to the tlv320aic3120 without success. So far only a full module remove of both eukrea and tlv320 will restore sound. remove and re-insert of either driver by itself does not work.
I have a few questions and areas where I would like advice.
0) What am i missing or doing wrong? Should I be taking a different approach altogether to this problem?
1) Should I migrate to simple-audio-card instead of eukrea-tlv320?
2) Suggestions on what needs to be reset/restored after the power rail comes back?
3) Suggestions on how best to trigger the reset/restore from either user space or the kernel?
Below is the relevant sections of our devicetree.
sound { compatible = "eukrea,asoc-tlv320"; eukrea,model = "pp-gen3display-tlv320aic3120"; ssi-controller = <&ssi2>; fsl,mux-int-port = <2>; fsl,mux-ext-port = <3>;
clocks = <&clks IMX6QDL_CLK_CKO>; };
&i2c1 { clock-frequency = <100000>; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_i2c1>; status = "okay";
tlv320aic3120: tlv320aic3120@18 { reg = <0x18>; }; ...
&ssi2 { codec-handle = <&tlv320aic3120>; status = "okay"; }; &audmux { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_audmux>; status = "okay"; }; pinctrl_audmux: audmuxgrp { fsl,pins = < MX6QDL_PAD_CSI0_DAT7__AUD3_RXD 0x130b0 MX6QDL_PAD_CSI0_DAT4__AUD3_TXC 0x130b0 MX6QDL_PAD_CSI0_DAT5__AUD3_TXD 0x110b0 MX6QDL_PAD_CSI0_DAT6__AUD3_TXFS 0x130b0 MX6QDL_PAD_GPIO_2__GPIO1_IO02 0x17059 MX6QDL_PAD_CSI0_MCLK__CCM_CLKO1 0x130b0 >; };
Attached is our changes to the eukrea driver to support the TLV320AIC31xx in our system.
Thank you,
Dexter Travis
