Messages in this thread | | | Subject | Re: [PATCH v5 0/6] drivers/i2c: Add FSI-attached I2C master algorithm | From | Christopher Bostic <> | Date | Tue, 15 Aug 2017 11:28:50 -0500 |
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On 8/15/17 3:10 AM, Joel Stanley wrote: > On Tue, Aug 15, 2017 at 4:06 PM, Peter Rosin <peda@axentia.se> wrote: >> On 2017-07-26 19:13, Eddie James wrote: >>> From: "Edward A. James" <eajames@us.ibm.com> >>> >>> This series adds an algorithm for an I2C master physically located on an FSI >>> slave device. The I2C master has multiple ports, each of which may be connected >>> to an I2C slave. Access to the I2C master registers is achieved over FSI bus. >>> >>> Due to the multi-port nature of the I2C master, the driver instantiates a new >>> I2C adapter for each port connected to a slave. The connected ports should be >>> defined in the device tree under the I2C master device. >> Hmmm, AFAIU fsi is a bus, and on this bus you have some "client" device that >> happens to be an i2c master, and this is a driver for that "client". Is it >> totally inconceivable to have some other client device in the future that is >> implementing an i2c master differently, but still using the fsi bus? >> >> With that in mind, is it wise to pick the driver name from the bus that the >> device is connected to, and nothing else without further qualification? >> >> I don't see any "i2c-usb" driver, but I think there are a couple of i2c master >> drivers that communicate via usb. > You make a fair point. When I did a prototype of this driver I called > it i2c-cfam, as it is part of the CFAM hardware unit inside of the > Power8/Power9 processors. > > The documentation does call it FSI_I2CM, so that's an argument for the > current name. > > I'm not sure how accurate that name is. Chris, Eddie, do you have any > other suggestions? The I2C engine up to now has been always accessed via the FSI bus so historically I assume that's why its labelled as FSI_I2CM in the p8/p9 specs. There isn't any reason this I2C device couldn't be implemented in some other topology independent of FSI / CFAMs. In other words there are no FSI details internal to this I2C engine, an argument for removing the 'FSI' tag.
Thanks, Chris
> > Cheers, > > Joel >
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