One of the biggest differences between working on most other OSs and working upstream on drivers for the Linux kernel is that elsewhere the core is usually a fixed thing that has been released and can’t really be changed, even if source is available (which may not even be the case). If whatever subsystem you’re [...]
Building the kernel for the Nexus S is straightforward – the kernel is public as one would expect so it’s simply a matter of building it using the standard Linux build system (the machine is called herring in the code). There is one gotcha, though – the driver for the BCM4329 WiFi controller is a [...]
Kernel 2.6.38 will add support for tracing ASoC using trace points. Previously all logging for ASoC had been done using printk(), meaning that changing the active logging required a kernel rebuild and that when trace was enabled the volume of trace could easily become very disruptive to other logging within the system. Trace points solve these [...]
2.6.37, which was released today, has been a very big release for ASoC – about 40,000 lines of changes covering every single file within the subsystem plus a bunch of new drivers. The highlights are: Overhaul of the core APIs for registration of all kinds of devices from my co-maintainer Liam Girdwood, reducing the level of [...]
Since I couldn’t seem to readily find any useful instructions for building firmware images for the Nexus S I thought I’d publish some. In a clean directory this sequence of commands should result in a working set of application layer images. They assume you’ve already got all the Android build dependencies installed: repo init -u [...]
Linux 2.6.36 was released today. This has been a very quiet release for the ASoC core code but one of the busiest releases for a while for new CPU support, with four new architectures added: CODEC support for JZ4740, WM8741, and WM8987 CPU drivers for EP93xx, JZ4740, Marvell Kirkwood/Orion I2S, NUC900, and SH S/PDIF Machine [...]
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 [...]
As Lennart just posted the Call for Papers for the 2010 Linux Plumbers Conference (LPC)closes this Monday (the 19th of July). The goal of LPC is to get people working on the various projects that make up the key Linux infrastructure where the kernel and application layers meet together so that everyone understands everyone else’s [...]
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 [...]