ADC Driver AM335x

Naven

Intellectual 750 points

hi,

am plan to write a new driver for AM335x and create a node in dev

fallowing some procedure based on data sheet

enable stepconfig ,set channel etc .

steps :

diff = diff |(1 << 25);
    iowrite32(diff,base_addr + IDLECONFIG);

    stepen = stepen |((1 << 1) ;                //enabled 1 stepconfig register/
    iowrite32(stepen,base_addr + STEPENABLE);

    stpcnfg = stpcnfg|((1 << 20)|(1 << 21 )|(1 << 19)|(1 << 5)|(1 << 9)|(1 << 7));
    iowrite32(stpcnfg,base_addr + STEPCONFIG1);     //stepconfig reg 1

    cntl = cntl | ((1 << 0) | (1 << 1)| (1 << 2)); //TSC_ADC_SS enble,step_write protected
    iowrite32(cntl,base_addr + 0x40);

     data = ioread32(base_addr + FIF0DATA); //FIFO0_data

but not get exact output

please suggest me how to write new driver for adc in continuous mode

steps for how to enable registers.

its urgent requirement

Thanks & Regards,

Naveen Kumar.

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi Naveen,

We do not have guidelines for development of new Linux drivers for the AM335X ADC. The ADC driver included in SDK 7.0 supports continuous mode (http://processors.wiki.ti.com/index.php/Linux_Core_ADC_User's_Guide ). You can use these sources as a reference.

0 Naven over 10 years ago in reply to Biser Gatchev-XID

Intellectual 750 points

hi Biser,

my target create node in dev files and reading data through node
when am reading data in fifo0 -- 3883 ,3843 etc get this values
but when am change different channels in stepconfig1
it will reflect same values all channels,
channel 7 only conncected vdd voltage,remaining are open so
how get this values ??

so please give me any ides and suggest me

Thanks & Regards,
Naveen.

so

0 Biser Gatchev-XID over 10 years ago in reply to Naven

TI__Guru**** 393215 points

p naveen kumar said:
channel 7 only conncected vdd voltage,remaining are open so how get this values ??

What is vdd voltage? Do you mean to say you are using only channel 7 of the ADC and nothing connected to the other channels?

0 Naven over 10 years ago in reply to Biser Gatchev-XID

Intellectual 750 points

hi sir,

iam reading AIN7 means 7 channel this pin connected to VDD
so whan iam reading some values will get like 883 ,3843 ect
but AIN0 -AIN6 (chnl0 chnl6) will get same values
how it is possible ???

stpcnfg = ioread32(base_addr + STEPCONFIG1);
stpcnfg = stpcnfg |((1 << 21)|(0 << 20)|(1 << 19));
iowrite32(stpcnfg,base_addr + STEPCONFIG1); //stepconfig reg 1
o/p values :val =3916 t=:2.805417 ms

Thanks & Regards,
Naveen

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ADC Driver AM335x