Linux 2.6.35 has been a fairly interesting release from an ASoC point of view, with several notable framework enhancements: Support for keeping audio paths through the CODEC up during system suspend, primarily intended for use with devices where the Linux system is one of several independent systems running on the device and the other systems [...]
Linux 2.6.34 was released today. This contains a fairly substantial batch of ASoC updates, including: Support for turning CODEC biases off completely when idle, providing power savings for modern devices with ground referenced outputs where this can be done quickly at runtime without pops and clicks. Support for disabling physical writes to the device in [...]
This has been another fairly quiet release for ASoC. Aside from the addition of virtual mux support to DAPM and some further preparatory work for multi-CODEC cards the majority of changes have been driver updates, including: New CODEC drivers for ADS117x, AK4671, TLV320DAC33, TPA6130A2, WM8711 and WM8727. Support for the PCM port on Samsung SoCs. Substantial improvements to [...]
Linux 2.6.32 was released overnight. This has been a fairly busy release for ASoC, with changes including: Redone power sequencing code, giving shorter power sequences which should reduce the effect of any artifacts that exist. Reporting of power management decisions via debugfs, enabling much easier diagnosis of path setup problems. Beginning of work to factor [...]
Linux 2.6.31 was released today. This was a fairly busy release for the ASoC subsystem, with updates including: DAPM supply widget, for automatically managing things like charge pumps and gateable clocks which may be used by more than one widget. Core support for setting up constraints for symmetric sample rates (for systems with a shared [...]
Ever since PulseAudio started to be deployed by distributions the most common complaint I’ve seen about ALSA is that unlike current versions of OSS it doesn’t provide mixing of audio from multiple applications inside the kernel. Of course what it really comes down to is that people want the system to transparently allow multiple applications [...]
Linux 2.6.30 was released today. This has been a fairly quiet release from the ASoC point of view with no substantial API changes for drivers but there’s a few new interfaces which people may find helpful. Highlights include: A simple wrapper for the standard ALSA jack detection interface. This helps makes jacks a bit easier [...]
I recently implemented some enhancements to DAPM, the part of ASoC which minimizes the power consumption of the embedded audio subsystem by keeping any unused components powered off while avoiding audible artifacts as the power changes. Prior to these changes DAPM used to change the power for each component with an individual register write which [...]
The 2.6.27 pull request for ALSA was something of a surprise to read – a large proportion of the changes in there are for ASoC. Not what I was expecting given how many ASoC changes there are still to be merged, but it’s nice to see, especially given the general problems with embedded users contributing [...]