Messages in this thread |  | | Subject | Re: [PATCH v1 1/1] i2c: iproc: Add i2c repeated start capability | From | Ray Jui <> | Date | Tue, 3 Sep 2019 16:11:16 -0700 |
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On 8/31/19 2:49 AM, Wolfram Sang wrote: > Hi Ray, > >>> With all the limitations in place, I wonder if it might be easier to >>> implement an smbus_xfer callback instead? What is left that makes this >>> controller more than SMBus and real I2C? >>> >> >> Right. But what is the implication of using smbus_xfer instead of >> master_xfer in our driver? >> >> Does it mean it will break existing functions of the i2c app that our >> customers developed based on i2cdev (e.g., I2C_RDWR)? > > If the customers uses I2C_RDWR (and it cannot be mapped to i2c_smbus_* > calls) then this is an indication that there is some I2C functionality > left which the HW can provide. I'd be interested which one, though. > >> >> 1) Does > > Maybe you wanted to describe it here and it got accidently cut off? >
I think you are right that the controller does not seem to support additional I2C features in addition to SMBUS.
However, my concern of switching to the smbus_xfer API is:
1) Some customers might have used I2C_RDWR based API from i2cdev. Changing from master_xfer to smbus_xfer may break the existing applications that are already developed.
2) The sound subsystem I2C regmap based implementation seems to be using i2c_ based API instead of smbus_ based API. Does this mean this will also break most of the audio codec drivers with I2C regmap API based usage?
Thanks,
Ray
> Regards, > > Wolfram >
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