[PATCH v4 01/11] mfd: add pruss mfd driver.

[subhasish@mistralsolutions.com (Subhasish Ghosh)]

> Instead of passing a configuration file into the MFD driver and
> calling it a firmware, I can see three other options that I believe
> would be nicer:
> 
> 1. have a single firmware blob that describes the child devices
> and the code that is to be loaded into both units. If they are
> acting as one device, either make sure you only create one
> child node, or create one with a name that no driver binds to.
> 
> 2. Call request_firmware separately for the two child devices,
> and configure them separately based on the information in the
> firmware files. In the case where they should act as a single
> device, call the children e.g. "pruss-uart-a" and "pruss-uart-b",
> then bind to both names in the pruss-uart drivers and only
> start using the device when you have both nodes for the same
> parent.
> 
> 3. Do the configuration through sysfs files in the MFD device node,
> which then cause the creation of the child devices. This means you
> need extra user space scripts to write the addititonal files, but
> is also the most flexible way.
> 

Are you suggesting something like:

/sys..../pruss/pru0/id
/sys..../pruss/pru0/fw_name
/sys..../pruss/pru0/load

/sys..../pruss/pru1/id
/sys..../pruss/pru1/fw_name
/sys..../pruss/pru1/load

I can program these configs and store them in the pru private.
Then write something into load.
This can load the PRU based upon the configs.
But, I am not sure how to do this effectively using sysfs,
I mean I don't want to end up writing six write and six read
handlers.