i2c still not working for me

Emmanuel Vadot manu at bidouilliste.com
Tue Apr 9 08:16:50 UTC 2019


On Tue, 9 Apr 2019 11:04:23 +0300
Daniel Braniss <danny at cs.huji.ac.il> wrote:

> 
> 
> > On 9 Apr 2019, at 10:58, Emmanuel Vadot <manu at bidouilliste.com> wrote:
> > 
> > On Tue, 9 Apr 2019 10:50:22 +0300
> > Daniel Braniss <danny at cs.huji.ac.il> wrote:
> > 
> >> Hi,
> >> after the latest changes to i2c there is a small improvement,
> >> i2c -s finds the device but complains:
> >> 
> >> root at neo-14:~ # i2c -s
> >> Hardware may not support START/STOP scanning; trying less-reliable read method.
> >> Scanning I2C devices on /dev/iic0: 24
> >> 
> >> but nothing else works.
> >> 
> >> I?ll try and connect my saleae signal analyzer later, but  in the meantime this is what I get
> >> on the console:
> >> [?]
> >> iichb0: twsi_control_clear: read val=58
> >> iichb0: twsi_control_clear: write val=40
> >> iichb0: TWSI_WRITE: Writing 40 to c
> >> iichb0: twsi_start: twsi_start: slave=48
> >> iichb0: twsi_locked_start: send start
> >> iichb0: TWSI_READ: read 58 from c
> >> iichb0: twsi_control_set: read val=58
> >> iichb0: twsi_control_set: write val=68
> >> iichb0: TWSI_WRITE: Writing 68 to c
> >> iichb0: twsi_poll_ctrl: Waiting for ctrl r.
> >> eg to match mask 8
> >> iichb0: TWSI_READ: read 48 from c
> >> gic0: iichb0: Spurious interrupt detected: last irq: 32 on CPU1
> >> twsi_poll_ctrl: done
> >> gic0: iichb0: Spurious interrupt detected: last irq: 32 on CPU1
> >> TWSI_READ: read 8 from 10
> >> iichb0: twsi_locked_start: status=8
> >> iichb0: TWSI_WRITE: Writing 48 to 8
> >> gic0: Spurious interrupt detected: last irq: 32 on CPU1
> >> iichb0: TWSI_READ: read 48 from c
> >> gic0: iichb0: Spurious interrupt detected: last irq: 32 on CPU1
> >> twsi_control_clear: read val=48
> >> gic0: iichb0: Spurious interrupt detected: last irq: 32 on CPU1
> >> twsi_control_clear: write val=40
> >> gic0: iichb0: Spurious interrupt detected: last irq: 32 on CPU1
> >> TWSI_WRITE: Writing 40 to c
> >> gic0: Spurious interrupt detected: last irq: 32 on CPU1
> >> iichb0: twsi_poll_ctrl: Waiting for ctrl reg to match mask 8
> >> gic0: iichb0: Spurious interrupt detected: last irq: 32 on CPU1
> >> TWSI_READ: read 48 from c
> >> iichb0: twsi_poll_ctrl: done
> >> iichb0: TWSI_READ: read 8 from 10
> >> iichb0: twsi_locked_start: no ACK (status: 08) after sending slave address
> >> gic0: iichb0: Spurious interrupt detected: last irq: 32 on CPU1
> >> twsi_stop: twsi_stop
> >> [?]
> >> 
> >> BTW, the hardware is NanoPi-neo and it?s running Current 345984
> >> 
> >> thanks,
> >> 	danny
> >> 
> > 
> > Based on the function names you are using directly stop/start/etc ...
> > My changes were only for i2c_transfer (I2CRDWR ioctls)
> > 
> 
> ok, this will show my ignorance, but could you send me some sample code that uses I2CRDWR?
> btw, the device i?m trying out is an RFID reader pn533, which works with a modified driver ?
> 
> thanks,
> 	danny

 You can have a look at i2c(8) source code, it uses RDWR.
 Basically you give the ioctl some i2c messages (struct iic_rdwr_data).
 Also man 4 iic

-- 
Emmanuel Vadot <manu at bidouilliste.com> <manu at freebsd.org>


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