>
> *>  i2cdetect -l*
> *> on Beaglebone Black it will give you:*
> *i2c-0   unknown         OMAP I2C adapter                        N/A*
> *i2c-1   unknown         OMAP I2C adapter                        N/A*
>

Ok, so I2C to the PMIC does work. A person on the group got this working
from within uboot and posted about it over a month ago.

When i asked, "ok great, but how does that translate to this working while
under linux?" He / she replied: something to the effect of "I'm unsure".

Anyway, the point is it is possible to control the PMIC, or at minimum
communicate with it via software + I2C. I am however not a Linux kernel
expert / guru, but I *would* assume this would require a kernel level
driver to work.


On Tue, Nov 25, 2014 at 2:31 PM, <[email protected]> wrote:

> Hi liyaoshi,
>
> So how can I measure the charge percentage left in the battery? Is there
> an example that I can use? TPS65217 does not allow us to read the battery
> voltage if I am right or at least I cannot find it in datasheet. what
> voltage are you talking about?
>
> I did some progress with controlling PMIC and I can use i2c utilities to
> read and write to it. However I have to use -f to force it since kernel is
> using the I2C interface. How can I do this cleanly from user space without
> forcing it? One way would be to expand the driver to add extra features.
> Does anyone know a good example that I can use as starting point? Is there
> a better/easier way to do this?
> my procedure is as follow:
>
>  i2cdetect -l
> on Beaglebone Black it will give you:
>
> i2c-0   unknown         OMAP I2C adapter                        N/A
>
> i2c-1   unknown         OMAP I2C adapter                        N/A
>
>
> For reading status register of TPS65217. device is at 0x25 and status
> register is 0x0a on I2C0
>
> i2cget [-f] [-y] i2cbus chip-address [data-address [mode]]
>
>
> sudo i2cdet -f 0 0c24 0x0a
>
> WARNING! This program can confuse your I2C bus, cause data loss and worse!
>
> I will read from device file /dev/i2c-0, chip address 0x24, data address
>
> 0x0a, using read byte data.
>
> Continue?
> [Y/n]
> 0x88
>
>
> To set battery charging voltage to 4.2V
>
> i2cset [-f] [-y] [-m mask] [-r] i2cbus chip-address data-address [value]
> ... [mode]
> sudo i2cset -f -m 0x30 0 0x24 0x05 0x20
>
> WARNING! This program can confuse your I2C bus, cause data loss and worse!
>
> I will write to device file /dev/i2c-0, chip address 0x24, data address
>
> 0x05, data 0x20 (masked), mode byte.
>
> Continue? [Y/n]
>
> Old value 0x80, write mask 0x30: Will write 0xa0 to register 0x05
>
> Continue? [Y/n]
>
>
> Thanks a lot
>
>
>
> On Monday, November 24, 2014 6:08:45 PM UTC-8, liyaoshi wrote:
>>
>> As I know , if only 2 wires , you can not access the Li+battery status ,
>> you can just get voltage value from PMU
>>
>> There always another 1 wire to get the communication with MCU in battery
>> module
>>
>> 2014-11-25 8:52 GMT+08:00 <[email protected]>:
>>
>>> Hi All,
>>>
>>> I connected a rechargeable Li+ battery to my BBB TP5, TP6, TP7, and TP8.
>>> I shorted TP5 and TP6 and added a 10uF decoupling capacitor. In addition, I
>>> connected TS to GND with a 9K resistor which is 10K || 75K according to the
>>> datasheet and the board boots fine from battery.
>>> Now my question is that how can I monitor the battery status(how much
>>> they are charged) or change the setting of PMIC, TPS65127C from shell. For
>>> instance, I would like to set the charging voltage to 4.2 rather than the
>>> default 4.1V. Or I would like to turn on/off WLED etc. Is there a tool,
>>> like Alsamixer, for this? if not what would be the best approach for
>>> controlling PMIC from shell? I posted it here because PMIC uses I2C
>>> interface to talk to AM335x.
>>>
>>>
>>> <https://lh4.googleusercontent.com/-E-wdJPfnG5U/VHPNaDDU9WI/AAAAAAAAAAo/tEjegAyAzAM/s1600/bbb-batt-srm.jpg>
>>>
>>>
>>> <https://lh3.googleusercontent.com/-d7FQ9BVS6J4/VHPNtiSxI4I/AAAAAAAAAAw/3_g2aL5Q2K4/s1600/bbb-batt1.jpg>
>>>
>>> Thanks for your time and consideration.
>>>
>>>  --
>>> For more options, visit http://beagleboard.org/discuss
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>>
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