[lm-sensors] dual output buck controller pmbus based

[lm-sensors] dual output buck controller pmbus based

[Vivek Bardia]

[-- Attachment #1.1: Type: text/plain, Size: 216 bytes --]

Hello,

I want to know whether does the current pmbus driver support dual output
buck controller based PMIC?

Basically for this particular PMIC: http://goo.gl/BFwcu

How do I test the driver for it?

Regards,
Vivek

[-- Attachment #1.2: Type: text/html, Size: 352 bytes --]

[-- Attachment #2: Type: text/plain, Size: 153 bytes --]

_______________________________________________
lm-sensors mailing list
lm-sensors@lm-sensors.org
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors

Re: [lm-sensors] dual output buck controller pmbus based

[Guenter Roeck]

On Fri, Feb 10, 2012 at 01:20:25AM -0500, Vivek Bardia wrote:
> Hello,
> 
> I want to know whether does the current pmbus driver support dual output buck
> controller based PMIC?
> 
> Basically for this particular PMIC: http://goo.gl/BFwcu
> 
This is the TI TPS40422. I have not had a chance to test it, so I have no idea
if it will work.

> How do I test the driver for it?
> 
If you know the bus and I2C address, instantiate it with 

echo pmbus <address> > /sys/class/i2c-adapter/i2c-<bus>/new_device

You have to execute the command as root.

Example: Instantiate pmbus device on bus 0, address 0x20:

echo pmbus 0x20 > /sys/class/i2c-adapter/i2c-0/new_device

then execute the "sensors" command and see if you get some output, and if it makes sense.

Looking into the datasheet, the interpretation of the PMBus "page" command is a bit odd.
You might get four sets of registers. If so, the first set would reflect the first channel,
the second set the second channel, the third set is invalid, and the fourth set would reflect 
both channels. But that is just a guess.

Would be great if you can post the results to the list. If it doesn't work, turns out the
evaluation module was just $49, so I ordered one. Which means you'll get support one way
or another.

Guenter


_______________________________________________
lm-sensors mailing list
lm-sensors@lm-sensors.org
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors

Re: [lm-sensors] dual output buck controller pmbus based

[Guenter Roeck]

On Fri, Feb 10, 2012 at 01:20:25AM -0500, Vivek Bardia wrote:
> Hello,
> 
> I want to know whether does the current pmbus driver support dual output buck
> controller based PMIC?
> 
> Basically for this particular PMIC: http://goo.gl/BFwcu
> 
> How do I test the driver for it?
> 
Hi,

I got the evaluation board for TPS40422. Here is the output from the sensors command
after instantiating it as "pmbus".

pmbus-i2c-0-1b
Adapter: i2c-diolan-u2c:002
vout1:        +1.20 V
vout2:        +3.30 V
temp1:        +26.0°C  (high = +100.0°C, crit = +125.0°C)
iout1:        +0.31 A  (max = +25.00 A, crit max = +30.00 A)
iout2:        +0.31 A  (max = +20.00 A, crit max = +25.00 A)

Similar, for TPS40400:

pmbus-i2c-0-1c
Adapter: i2c-diolan-u2c:002
vin:         +11.59 V
vout1:        +1.16 V  (crit min =  +1.14 V, crit max =  +1.26 V)
iout1:        +0.50 A  (max = +29.00 A, crit max = +30.00 A)

Overall pretty good for generic detection. Only problem (or, rather, limitation)
with TPS40422 is that the auto-detection code does not support paged temperature
registers, and thus only a single temperature is reported.

Did you have a chance to test it yourself ?

Thanks,
Guenter

_______________________________________________
lm-sensors mailing list
lm-sensors@lm-sensors.org
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors

Re: [lm-sensors] dual output buck controller pmbus based

[Vivek Bardia]

[-- Attachment #1.1: Type: text/plain, Size: 2066 bytes --]

Hi Guenter,

I still do not have any evaluation hardware.

By the way, my usage for TPS40400/TPS40422 is just output voltage control.
Have no sensors being used in my scenario.

Will you be able to comment on my below steps and its validity:

1. To get the current output I do a READ_VOUT and then convert it to
microvolts format, for e.g. finally i get 942734uV

2. To set a output voltage to say 902234 based on some requirement,
My nominal voltage being 1.1V
hence trim_offset = 902234 - 1100000
therefor I do: PMBUS_VOUT_TRIM with a value ffa7

Is the above logic right? my VOUT_SCALE_LOOP is
600mV/1100mV x (2^9) = 279.27 => 100010111 => *b917*

Regards,
Vivek

On 22 February 2012 09:45, Guenter Roeck <guenter.roeck@ericsson.com> wrote:

> On Fri, Feb 10, 2012 at 01:20:25AM -0500, Vivek Bardia wrote:
> > Hello,
> >
> > I want to know whether does the current pmbus driver support dual output
> buck
> > controller based PMIC?
> >
> > Basically for this particular PMIC: http://goo.gl/BFwcu
> >
> > How do I test the driver for it?
> >
> Hi,
>
> I got the evaluation board for TPS40422. Here is the output from the
> sensors command
> after instantiating it as "pmbus".
>
> pmbus-i2c-0-1b
> Adapter: i2c-diolan-u2c:002
> vout1:        +1.20 V
> vout2:        +3.30 V
> temp1:        +26.0°C  (high = +100.0°C, crit = +125.0°C)
> iout1:        +0.31 A  (max = +25.00 A, crit max = +30.00 A)
> iout2:        +0.31 A  (max = +20.00 A, crit max = +25.00 A)
>
> Similar, for TPS40400:
>
> pmbus-i2c-0-1c
> Adapter: i2c-diolan-u2c:002
> vin:         +11.59 V
> vout1:        +1.16 V  (crit min =  +1.14 V, crit max =  +1.26 V)
> iout1:        +0.50 A  (max = +29.00 A, crit max = +30.00 A)
>
> Overall pretty good for generic detection. Only problem (or, rather,
> limitation)
> with TPS40422 is that the auto-detection code does not support paged
> temperature
> registers, and thus only a single temperature is reported.
>
> Did you have a chance to test it yourself ?
>
> Thanks,
> Guenter
>

[-- Attachment #1.2: Type: text/html, Size: 2722 bytes --]

[-- Attachment #2: Type: text/plain, Size: 153 bytes --]

_______________________________________________
lm-sensors mailing list
lm-sensors@lm-sensors.org
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors

Re: [lm-sensors] dual output buck controller pmbus based

[Guenter Roeck]

On Wed, Feb 29, 2012 at 11:52:42PM -0500, Vivek Bardia wrote:
> Hi Guenter,
> 
Hi Vivek,

> I still do not have any evaluation hardware.
> 
Too bad.

> By the way, my usage for TPS40400/TPS40422 is just output voltage control. Have
> no sensors being used in my scenario.
> 
> Will you be able to comment on my below steps and its validity:
> 
> 1. To get the current output I do a READ_VOUT and then convert it to microvolts
> format, for e.g. finally i get 942734uV
> 
> 2. To set a output voltage to say 902234 based on some requirement, 
> My nominal voltage being 1.1V
> hence trim_offset = 902234 - 1100000
> therefor I do: PMBUS_VOUT_TRIM with a value ffa7
> 
> Is the above logic right? my VOUT_SCALE_LOOP is 
> 600mV/1100mV x (2^9) = 279.27 => 100010111 => b917
> 
I can not really comment on that. The procedure is different for each chip, 
not always easy to understand, and it often takes quite some time to find
a working configuration. Best is really to use the tools provided by TI
(the Fusion GUI is quite good), since there tend to be other parameters
which need to be configured as well. I use the TI tools even for the test
boards I built myself. The TPS40xxx series is not as difficult as the
UCD92xx series when it comes to configuration complexity, but I would
still suggest to use the tools. If you misconfigure the chip, you might
burn it, so it pays to be careful.

Did you have a look into http://www.ti.com/lit/ug/slvu638/slvu638.pdf ?

Thanks,
Guenter

_______________________________________________
lm-sensors mailing list
lm-sensors@lm-sensors.org
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors