The PMIC registers can be read using i2cget but writing to registers requires editing the password register http://www.ti.com/lit/ds/symlink/tps65217c.pdf Page 40. NOTE: All registers on the PMIC are set to default if the device moves from active to sleep or off state.
The eePROM can be read from using i2cget but is hardware write protected. On Thu, Jan 2, 2014 at 10:27 AM, Robert Nelson <[email protected]>wrote: > On Thu, Jan 2, 2014 at 10:11 AM, Robert Ianovich <[email protected]> > wrote: > > The question is why can't be accessed regularly from user space by > reading > > /dev/i2c-0 bus? > > The I2C buses and devices can't be owned exclusively even by kernel due > to > > I2C architecture, so as far as the bus is free, anyone should read/write > to > > any address. > > > > I have worked on many industrial boards considerably bigger than BBB > > (WindRiver kernel) and all devices with I2C for maintenance (RapidIO, > DSP, > > MAC/PHY, etc) are accessible. > > > > Why on BeagleBone the addresses of HDMI framer, PMIC and onboard EE are > > intentionally blocked by driver ? > > Or why the DRM driver is written that way? > > Well the hdmi/edid is the easly one.. As the beaglebone dose not have > direct access to that bus, take look at page 10: > > https://github.com/CircuitCo/BeagleBone-Black/blob/master/BBB_SCH.pdf > > Thus we need to query the TDA19988 device thru drm for the edid... > > As far as PMIC/EE are registered by the dts in i2c0: > > tps: tps@24 { > reg = <0x24>; }; > > baseboard_eeprom: baseboard_eeprom@50 { > compatible = "at,24c256"; > reg = <0x50>; }; > > Thus if that blocks access thru /dev/i2c-0, i guess it blocks it... > > Regards, > > -- > Robert Nelson > http://www.rcn-ee.com/ > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
