TAS5805M: Volume control though Linux driver

Hello Damien, 

Attached is the linux code for the TAS5805M, which should also be in the thread answered by Andy. 

Additionally, attached is a how to implement for the TAS5825M, but it applies to the TAS5805M since they both have the same start up sequence. 

TAS5825M Linux Driver and Startup Procedure.pdf6866.Linux Driver for TAS5805M.zip

All the best,
Carolina 

Hi Carolina,

thanks for your reply, but this does not help me: I am able to compile and to load the driver, that initializes the TAS5805M through i2c.

What I don't know is how to interact with it to control the volume from my Linux system.

In other words, how can I reach the tas5805m_set_volume driver function? Does it create any sysfs interface?

How to make alsamixer know about it?

Thanks.

Kind regards,

--

Damien

Hi Carolina,

thank you for your answer.

Unfortunately, those threads do not help neither: I have been able to generate an initial registers configuration through PPC3, and it is properly loaded by the Linux driver through i2c.

The only missing part is how to manage the volume control at runtime using that driver.

Kind regards,

--

Damien

Hey Damien, 

Is it possible to manage the volume control the same way that they Linux driver loads the register configuration? 

So with the example I showed above, the register output would be: 

w 58 00 00
w 58 7f 00
w 58 00 00
w 58 4c 20

{0x00, 0x00},
{0x7f, 0x00},
{0x00, 0x00},
{0x4c, 0x20} 

All the best,
Carolina 

Hi Carolina,

that is indeed what the proposed driver is supposed to do via the tas5805m_set_volume function.

But again, all the problem is to now how to call that function from the Linux audio system, using the ALSA framework.

Kind regards,

--

Damien

Hello Damien, 

We do not do software support, but hopefully you will find these journals helpful: 

https://www.linuxjournal.com/article/6735

https://www.kernel.org/doc/html/v4.17/sound/kernel-api/writing-an-alsa-driver.html

All the best,
Carolina