AM335X ADC Interrupt Support in Linux

Hari Prasath G.E

Other Parts Discussed in Thread: AM3359

Dear all,

We are developing a embedded system based on AM3359 running Linux for a Industrial automation application. The system gets Analog inputs which will be interfaced to the ADC of the AM3359. The analog input is a voltage level signal which has a specific range. The technical reference manual says that the ADC can generate interrupts for the following two conditions

Interrupt after a sequence of conversions
Interrupt if sampled data is out of a programmable range

Our requirement is to make use of these interrupts in the software. Does the existing Linux kernel of am3359 support handling these interrupts ? If not, would it be fine to write a new driver to make use of these interrupts. Which is the best possible way to do so ?

Also in the linux kernel source tree, which is the existing platform driver for the ADC.

drivers/mfd/ti_tscadc.c
drivers/staging/iio/adc/ti_adc.c

over 13 years ago

0 Kurtis Unger over 13 years ago

Prodigy 180 points

We have a similar situation. We would like to generate an interrupt when select analog inputs fall below a certain level.

Any insights in how to configure this in the kernel?

Thanks

0 Hari Prasath G.E over 13 years ago in reply to Kurtis Unger

Prodigy 235 points

Hi Kurtis,

The TI ADC driver in the kernel source @ drivers/staging/iio/adc/ti_adc.c in PSP version 4.06 doesn't seem to support ADC interrupts. However, the TI's latest PSP release 05.07 seems to have this support added. I haven't tested this myself.

Also the TI developers arago git repository shows that lot of new changes are included in the ADC driver. Refer the following link below

http://arago-project.org/git/projects/?p=linux-am33x.git;a=shortlog;h=refs/heads/v3.2-staging

Hope it helps

Regards,

0 Kurtis Unger over 13 years ago in reply to Hari Prasath G.E

Prodigy 180 points

Hi Hari,

Thanks for this information!

Did you mean SDK 5.07? As far as I can tell, 4.06 is the latest PSP but if you have a link to a newer PSP please pass it on.

Cheers

0 Hari Prasath G.E over 13 years ago in reply to Kurtis Unger

Prodigy 235 points

Hi Kurtis,

Yes its SKD 05.07. Thats what TI website says. Here is the URL to download the SDK

http://software-dl.ti.com/dsps/dsps_public_sw/am_bu/sdk/AM335xSDK/latest/index_FDS.html

You can download the source package alone(am335x-evm-sdk-src-05.07.00.00.tar.gz) or the entire SDK ti-sdk-am335x-evm-05.07.00.00-Linux-x86-Install.

Hope this helps.

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AM335X ADC Interrupt Support in Linux