Is there a way to fully dump the configuration of an Intel HDA-based audio codec, including current hardware state?
The interface at /proc/asound/card0/codec#0 only reflects what's known to the kernel, not the real hardware state.
The PCI configuration space (read with lspci -x) doesn't show much (it doesn't even show volume/amplifier gain values).
For context : I'm trying to debug an audio issue with my laptop, where headphones output white noise when resuming from standby. The white noise doesn't change when increasing volume, but disappears only when powering down the codec.
This leads me to believe that the issue is likely caused by either a buggy ACPI or a change in the codec's configuration, or even both. My goal is to get as much data as I can on before/after states and compare them, but both methods described above failed for me.
I found that hdajackretask as part of the alsa-tools-gui package on my Debian Stretch GNU/Linux Os looks very interesting in getting the internal parts of the sound-card in the right configuration for what I wanted.
I'm just looking to see whether it is portable to my other OS as I have only seem to have stereo audio on FreeBSD and I think this would help. In your case it might help your to decode how things are configured and to spot any changes. The normal screen is at least helpful in determining which connection is which:
What looks more interesting is the "Advanced override":
I am about to reboot and see whether I have managed to turn the grey connector be the "side"-channel outputs....
Related
I have a rooted Sony prs900, running a linux 2.6.23 #2 PREEMPT kernel, for ARMv6. (Montavista linux kernel). I'm having problems with figuring out how power management works, both for running the system and for powering up and down the audio port.
I can neither figure out how to read the battery/powerline status information, nor get the audio chip to play sound, etc ... although I have been studying the kernel modules for a while...
It's worth a little money for help, say $100 paypal donation to an email account, (or more if this takes a long time...) for the first person able to explain to me how to do them in a way that works.
Eg: read battery status, and change some power modes like getting the audio amplifiers to power up/down so that the audio played to /dev/dsp (oss emulation) actually comes out as sound rather than just being consumed by the chip and ignored...
The actual sony kernel, and binary packages of cross compiler tools are located on the main page. Actual kernel sourcecode is also available.
What I have learned so far myself :
The sony is using a wolfson micro WM8350 audio driver and battery charger/power management chip for all the system's power; eg: it can power down/up the SD memory cards, send more power to the cpu, power up audio amplifiers, etc. See: WM8350 Datasheet.
Pretty much, the whole problem revolves around getting the WM8350 kernel drivers to work...
Although the company brags quite a bit about it's support under linux, they don't have any application notes or examples that are actually helpful that I can find, other than the datasheet. I suspect the kernel drivers I have are beta code, because they don't seem to be behaving well (several error messages in the kernel log about wm8350 registers not being readable happen at every boot even when running only the sony's native software...).
The kernel driver's source-code of most interest are in: linux-2.6.23_091126/drivers/mxc/pmic/{core,wm8350}
Notice, the wm8350 is a competitor to the MC14783, but the linux kernel drivers use the same {core} driver source code for both chips; The sony ONLY has the wm8350 on it -- there is no MC14783 present.
The code that I most want most desperately to understand how to make operate is found in the subdirectory {wm8350}, eg: wm8350/wm8350pm/power_supply_sysfs.c.
I want the audio to fire up too, but 'm not quite sure where the pertinent audio amplifier code is yet...
Very clearly the wm8350pm code is designed to export a /sys directory interface; right now /sys is mounted and operational on the system; but I'm not very familiar with the semantics of these newer style interfaces... they aren't quite like the old APM power interfaces for Linux laptops...
First I checked the obvious:
If I do a "cat /sys/power/state" it returns the word "mem" and nothing else.
The file has permissions -rw-r--r--, so potentially it could be written -- but I don't know with what. The string "mem" does not exist anywhere in the source code for the wm8350pm drivers, so I don't even know if /sys/power/state is part of the source code.
Doing a find /sys -iname "wm8350" reveals a handful of directories with the patterns:
wm8350-rtc , wm8350-pmic , wm8350-bl , wm8350-power , wm8350-led
wm8350-hifi-dai , wm8350-codec
wm8350-imx32ads.0
So, I do an ls-l on each directory, and look for actual files rather than symbolic links or subdirectories, and what I find are stock useless writable files: bind, unbind, uevent,
and a very few read only files: pmic_reg, dapm_widget, modalias, codec_reg which aren't very helpful.
It's no surprise that:
Doing: cat /sys/devices/platform/wm8350-ebx5016-audi/modalias gives "wm8350-ebx5016-audio"
Doing: cat /sys/devices/platform/wm8350-imx32ads.0/modalias gives "wm8350-imx32ads"
and since audio is off... Doing: cat /sys/devices/platform/wm8350-ebx5016-audi/dapm_widget reveals the audio state:
Headphone Jack: Off
Line In Jack: On
Mic Bias: Off
Left DAC: Off
Right DAC: Off
... (all else off and omitted except )...
EBX5016-hifi: PM State: D3hot
The last two files, I expect should do wm8350 chip register dumps... and one did.
Doing: cat /sys/devices/wm8350-pmic/pmic-reg causes a long pause, then nothing is printed.
but:
Doing: cat /sys/devices/wm8350/platform/wm8350-ebx5016-audi/wm8350-codec/codec_reg does prints a list of registers up to e8 which is just a few bytes larger than the datasheet says the chip should be (0x00 to 0xe6).
I tried using a python program to play wav files, (works on my desktop computer), and I noticed that /dev/dsp does open, the mixers DO set volume levels, and nothing comes out. So -- the audio driver is not able to enable the sound amplifiers on it's own automatically.
There are no alsa sound files in /dev, nor are any alsa tools found on the embedded machine... so I assume Sony is strictly using OSS /dev/dsp and /dev/mixer.
There is only one other access point I can find to the ws8350:
There IS a device driver /dev/wm8350.
That driver created by the source code in subdirectory wm8350/wm8350_reg.c ; in theory it should be able to read and write to all registers using ioctls() calls from a user space. However, something appears grossly wrong with it, for I wrote a test program to read the wm8350 registers... and most of the registers return error messages rather than allowing to be read, including the most pulic ID registers (0x00, 0x01) etc.
So, I'm quite stuck. Pointers, thoughts, hints, are quite desired.
I would like to change your question a little bit.
How does Linux ASOC (alsa system on chip) power management work?
I will answer this and then give some hints on using this specific chip.
.. If I do a cat /sys/power/state it returns the word "mem" and nothing else. The file has permissions -rw-r--r--, so potentially it could be written -- but I don't know with what. The string "mem" does not exist anywhere in the source code for the wm8350pm drivers, so I don't even know if /sys/power/state is part of the source code.
You need to get an understanding of the Linux driver model. Hardware in Linux is structured like a tree. The rational is that things must be powered up/down in specific sequences. For instance, you should not power down the PCI bus controller before powering down the PCI peripherals. Linux builds a tree of hardware and each driver (code) and device (data/actual hardware) has specific call backs/function pointers which handle some specific tasks.
probe - Are you there? Determines actual hardware/device is present.
remove - Shuts down device. Module removal, power off, etc.
suspend - going to sleep.
resume - waking up.
Three and four may look interesting to you. Now, to read about what /sys/power/state is about. The text mem, means that suspend to memory is supported by your system. In this mode, Linux does these steps,
Find first lowest level active bus.
suspend devices on that bus.
suspend bus and de-activate.
If a bus is active go to step 1.
Set CPU to low power state (suspend to RAM).
This is not quite the full story. A few devices may support a wake-up. They will have extra call-backs to enable waking the system from sleep modes. Read the documentation to find out about this.
That is general power management and driver/device structure. Now, how is the ASOC (alsa system on chip) structured?
There are typically three drivers/devices that get stitched together.
Codec - The wm8350 in your case. This includes audio amplifier drive circuitry and can include sound mixing and source controls. Supports digital to analog and analog to digital, typically through an i2s interface. The i2s is not the only interface. Usually a register bank is controlled through a secondary interface; i2c in the wm8350 case.
DAI - Refer to chapter 1.2.18.1 of the iMx31 reference manual; the hardware is called the SSI by Freescale. The next chapter on the AUDMUX is also useful to understand audio support on the iMx31/32.
Machine file - this is the board specific routing. It hooks the DAI to the codec and is the parent of both. It provides board clocking information and other specific configuration. For instance, it may use the AUDMUX to route the physical pins to the SSI block.
An i2c (or SPI) interface from the codec driver to send control commands to the coded chip. Some chips might uses a wacky i2s interface or something else for control (but not in your case).
Now if you understood this, you will see that some features of the wm8350 seem to break the Linux model. The DAI interface can be stopped (digital audio), but the i2c interface must remain alive to program the registers related to the power functionality in the codec/PMIC (power management IC).
The latest WM8350 calls the IC a multi-function device and support was introduced in 2.6.35. The initial support may not have included the WM8350 features. Unfortunately, without some details on the layout of the Sony prs900 board, it would be difficult to know how to use the WM8350 PMIC functionality. The code will involve the iMx31 CPU, the WM8350, the i2c connection, and possibly some power supply circuitry.
For certain, you can just try echo mem > /sys/power/state and see what happens. If it works, you are lucky. The power/current consumption in sleep might not be optimal, but it will probably be hard to fix with the 2.6.23 kernel. You will want to look through the /sys directories for wake-up sources and possibly register these before issuing the suspend to memory command.
I can neither figure out how to read the battery/powerline status information, nor get the audio chip to play sound, etc ... although I have been studying the kernel modules for a while...
From the above discussions, the battery and powerline status will probably be found through another device. However, the pmic_reg file may actually give the status if things are connected properly on the board.
The audio chip will use ALSA. You need to use either alsamixer or the command line amixer to set up audio routes through the codec, so the DAI channel (PCM from iMx32) is routed and sent to the speaker. To minimize power consumption, things are usually turned off by default. The /dev/dsp files are just OSS compatibility. This configuration will support ALSA natively. You are better off to use ALSA if possible.
Donate to the OSF and get a tax receipt, if this was helpful enough.
I'm using a custom board running imx6q processor, and a tlv320aic3x audio codec.
Everything works ok after some bring-up, but I'm trying to improve the audio driver: whether I'm doing playback or capture - both playback and capture related amplifiers are switched on.
This causes side effects like noise in speakers when I'm capturing audio, and wastes power.
To solve this, I'm trying to define the data paths correctly in the driver, but I keep failing.
I find it hard to find resources on-line explaining how to code an ALSA driver using the ALSA predefined macros that exists in the Kernel.
I've searched http://www.alsa-project.org/, linux docs, and few other sources...
And to my questions:
Is there any decent tutorial out there? I'm specifically interested in DAPM and usage of control names.
Is it possible to "re-program" all driver data paths from userspace?
Is DAPM sufficient for decent power management? Or should I use userspace to switch on/off power from unused paths in the codec between playbacks and captures?
Just to be clear: in user space using the standard driver, I am able to do playback, capture and control mixers, switches, etc... However I'm trying to achieve better automatic power management.
Thanks
I have added a TSHARC touchscreen driver to my Windows CE project, but the touch does not work. The dll is there, as is the touchscreen calibration executable. I have no visibility into which drivers are loaded and when. Any guidance would be appreciated.
You're going to have to do some debugging, and touchscreen drivers tend to be challenging because they get loaded into GWES and because the electrical characteristics of touchpanels change dramatically based on size and manufacturer. It's very rare for a driver to just work right out of the box - you almost always have to adjust sample timings and the like based on panel characteristics, and that's best done using an oscilloscope.
Things to check:
Is the driver getting loaded at all? A RETAILMSG/DEBUGMSG would tell you that
Are you getting touch interrupts?
After a down interrupt, is your code getting back to state to receive an up?
If you look at the timings from panel signals themselves, are you sampling when the signals are stable (i.e. you're not sampling too soon after the interrupt)?
Turns out it was a conflict between the OHCI driver and another USB driver already installed.
I'm working on embedded device with screen rotated 90 degrees clockwise: screen controller reports 800x600 screen, while device's screen is 600x800 portrait.
What do you think, whose responsibility it is to compensate for this: should kernel rotate framebuffer to provide 800x600 screen as expected by upper-level software or applications (X server, bootsplash) should adapt and draw to rotated screen?
Every part of stack is free software, so there are no non-technical problems for modification, the question is more about logical soundness.
It makes most sense for the screen driver to do it - the kernel after all is supposed to provide an abstraction of the device for the userspace applications to work with. If the screen is a 600x800 portrait oriented device, then that's what applications should see from the kernel.
yes,I agree, The display driver should update the display accordingly and keep the control
Not sure exactly how standard your embedded device is, if it is running a regular linux kernel, you might check in the kernel configurator (make xconfig, when compiling a new kernel) , one of the options for kernel 2.6.37.6 in the device, video card section, is to enable rotation of the kernel messages display so it scrolls 90 degrees left or right while booting up.
I think it also makes your consoles be rotated correctly after login too.
This was not available in kernels even 6-8 months ago, at least not available in kernel that slackware64 13.37 came with about that time.
Note that the bios messages are still rotated on a PC motherboard,
but that is hard-coded in the bios, which may not apply to the embedded system you are working with.
If this kernel feature is not useful to you for whatever reason, how they did it in the linux kernel might be good example of where and how to go about it. Once you get the exact name of the option from "make xconfig", it should be pretty easy to search where ever they log the kernel traffic for that name and dig up some info about it.
Hmmm. I just recompiled my kernel today, and I may have been wrong about how new this option is. Looks like it was available with some kernel versions before the included-with-Slackware64 versions that I referenced. Sorry!
I have a problem probably with my arm toolchain but maybe there's something other that I do wrong. I have Chinese made dev board qq2440 using Samsung s3c2440 ARM9 uC. I'm using Ubuntu x86 with native gcc(4.3.3) and cross-compile version arm-unknown-linux-uclibc-gcc (crosstool-NG-1.3.2) 4.3.2
I followed tutorials from http://blog.leshak.ru/english/pages/how-to-install-u-boot-linux-2629-rootfsjffs2-busybox-1132-into-nand-qq2440/
and used Leshak's kernel patches for that board. Problem is that his binaries work perfectly and mine don't...
I communicate with my board over RS232 (serial port) and I have serial terminal configured on target Linux. I use Leshak's uboot image. To configure my kernel I use following command line:
qq2440> setenv bootargs 'noinitrd root=/dev/mtdblock2 rootfstype=jffs2 rw console=ttySAC0,115200'
For target I use vanilla Linux sources version 2.6.29, with patches created by Leshak. I don't honestly believe that this will ever be supported officially by Linux as it's not mainstream product.
My kernel image starts booting up, but it probably changes bandwidth (or CPU frequency) to some non standard value (tried all standard ones already). Instead of dots indicating loading kernel into memory I've got only trash instead. Unfortunately it doesn't probably finish the boot process as the network interface nor file system don't come up. So I figured out that it panics somewhere in the middle.
Any ideas what should I do next?
Thanks & regards,
Chris
There are a lot of different things that could be going on here.
It sounds like you are talking about a serial port, and that it appears to be giving garbage once control is passed to the kernel from uboot. Am I understanding that correctly?
Look into specifying the baud rate, parity, etc. for the serial console on the kernel commandline.
Oh, and IIRC, there was some 'early_printk' thing in the ARM Linux tree that might help you debug serial console problems. (But I'll warn you -- it's been a couple years since I dealt with that so my memory is fuzzy.)
Double-check that the memory address layout (the locations of all the various devices) matches what your board has. (I think this is probably not the issue, but wanted to mention it for completeness.)
You say that you have a binary kernel that works correctly; compare the kernel config of that kernel to the config you are using for building your kernel. Investigate every difference, particularly any specific to ARM.
You may want to double-check the endianness of your toolchain vs what your board is expecting. Some of the ARM / XScale processors can be configured to big-endian or little-endian in software, so it might be worth double-checking.
Just enable the debug build of the kernel[while building the uImage] so that you get a more clearer picture of the scenario [Just would make your boot up somewhat slow since all the printk's would be enabled].
Can you check whether you are passing the correct parameters to the UART ie. Serial Port Name, it's baud rate etc This would be provided by the board manufacturer-Samsung
WRT the network instead of DHCP can you just assign a static ip address to your system as it might be possible that the DHCP process is still not ON.
Also a better option would be to use NFS but yeah, it depends on your choice and the purpose of your application. To use NFS, your network should be UP & running and your filesystem should be shared.
As retracile has already pointed out "Endianness" could be a point to look into !!!
You can refer this link which might help you out since it is specific to S3C2440
Hope this helps.
-hjsblogger
I had a similar problem at one point when I omitted --send-cmd from picocom. this is the command I issue to picocom for serial uBoot comms with the mini2440.
picocom -b 115200 /dev/ttyS0 --send-cmd "sx -vv"