[Qemu-devel] i2c data address question was Re: [PATCH RFC] i2c-tiny-usb

[Tim Sander <tim@krieglstein.org>]

Hi Paolo and List

Am Freitag, 27. November 2015, 13:53:22 schrieb Paolo Bonzini:
> On 27/11/2015 13:39, Tim Sander wrote:
> > I have one more thing, i2cdetect looks like this:
> >      0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
> > 
> > 00:          03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
> > 10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
> > 20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
> > 30: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
> > 40: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
> > 50: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
> > 60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
> > 70: 70 71 72 73 74 75 76 77
> > 
> > But i only have a device at 0x50 so most numbers should be "--".
> > I know that i just have to set the read length to zero, to archive that.
> > Currently i don't know how to determine if there is something registered
> > on
> > the requested i2c address?
> 
> If there is no slave at the requested address, i2c_start_transfer will
> return 1.
Ok, that works. Now probably the last problem i see is that i fail to set the 
data-address of the i2c-device?
I know the correct offset address for accesses on the bus e.g. 
i2cget -y 0 0x50 2
where 2 is an example offset for the access to this device. 

So any hint how setting the data-address on the i2c bus in qemu works?

I have seen the function i2c_set_slave_address but i guess thats not the right 
function setting the data address.

Best regards
Tim