According to the SRM 0x70 should be the HDMI Framer Processor Interface. see page 73.
-- Dan Metcalf -- KB3UUN On Thu, Jan 2, 2014 at 12:06 PM, Cody Lacey <[email protected]> wrote: > I think 0x34 is the HDMI framer. > > > On Thu, Jan 2, 2014 at 10:58 AM, Robert Nelson <[email protected]>wrote: > >> 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... >> >> btw the "UU" from i2cdetect in 0x24/0x50 give you a hint that the >> normal i2cXYZ can't access them as they are currently busy (with the >> kernel).. >> >> root@beaglebone:~# i2cdetect -y -r 0 >> 0 1 2 3 4 5 6 7 8 9 a b c d e f >> 00: -- -- -- -- -- -- -- -- -- -- -- -- -- >> 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- >> 20: -- -- -- -- UU -- -- -- -- -- -- -- -- -- -- -- >> 30: -- -- -- -- 34 -- -- -- -- -- -- -- -- -- -- -- >> 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- >> 50: UU -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- >> 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- >> 70: 70 -- -- -- -- -- -- -- >> >> (no idea where 0x34/0x70 are coming from at the moment..) >> >> 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. > -- 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.
