On Wed, 2005-07-13 at 11:04 -0400, Bryan Mayland wrote: > Richard Röjfors wrote: > > >I have an intel chipset which can do smbus, what is the difference > >between smbus and i2c btw? I know that because previously I got a lot of > >warnings (hundreds) indicating that i2c transfers were not supported. > > > > > SMBus is a wire protocol, which may be implemented on top of an i2c > bus. I2C provides the physical bus to get bytes on the wire, SMBus > describes what the bytes mean. For example, an SMBus byte write is > defined as > Start Bit - 7 bit I2C address - Write Bit (0) - (wait for ack bit from > client) - Data byte - (wait for ack bit) - Stop Bit > > The conexant cx25840 digitizer doesn't speak SMBus, so we have to use a > I2C-level (raw) transfer, which the cx23416 lets us do. The old cx25840 > detect code didn't check to see if raw transfers were supported, so any > i2c client on 0x44 was assumed to be a cx25840. Of course, that is > wrong but has been fixed.
Okay! Thanks for the information! > > >cx25840: Module init > >cx25840: starting probe for adapter ivtv i2c driver #0 (0x10005) > > > > > I have been seeing a lot of this recently. Normally that would be > followed by a line where it says that it found a cx25840 at 0x44, and > then give the revision number. For some reason the i2c_probe isn't > working. I've seen this in several people's logs both with PVR-150s and > 500s. I'm not sure what's causing it though. It can be one of a few > things: > -- The ivtv i2c adapter isn't reporting it supports > I2C_FUNC_SMBUS_QUICK. Is there a version of i2c-algo-bit that doesn't > doesn't report functionality I2C_FUNC_SMBUS_EMUL? How to check this? I looked briefly into the code and saw that there was a lot callbacking going on :) So if you could give me some pointers how to check that would save me a lot of time. > -- i2c_check_addr() returns that 0x44 is already in use. One could > probably check sysfs to see if this is the case > (/sys/devices/platform/i2c-X/ would have an directory entry for X-0044) > -- The i2c_smbus_xfer(QUICK) is faling. What? Why would that happen? I checked /sys/devices/platform there was not i2c addresses used, after loading ivtv, i2c-1 is in use. > > > > ------------------------------------------------------- > This SF.Net email is sponsored by the 'Do More With Dual!' webinar happening > July 14 at 8am PDT/11am EDT. We invite you to explore the latest in dual > core and dual graphics technology at this free one hour event hosted by HP, > AMD, and NVIDIA. To register visit http://www.hp.com/go/dualwebinar > _______________________________________________ > ivtv-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/ivtv-devel > ------------------------------------------------------- This SF.Net email is sponsored by the 'Do More With Dual!' webinar happening July 14 at 8am PDT/11am EDT. We invite you to explore the latest in dual core and dual graphics technology at this free one hour event hosted by HP, AMD, and NVIDIA. To register visit http://www.hp.com/go/dualwebinar _______________________________________________ ivtv-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ivtv-devel
