[U-Boot] [PATCH] 7/12 Multiadapter/multibus I2C, drivers part 4

[ksi at koi8.net]

On Wed, 18 Feb 2009, Heiko Schocher wrote:

> Hello ksi,
> 
> ksi at koi8.net wrote:
> > On Mon, 16 Feb 2009, Wolfgang Denk wrote:
> > 
> >> Dear ksi at koi8.net,
> >>
> >> In message <Pine.LNX.4.64ksi.0902142019520.6240 at home-gw.koi8.net> you wrote:
> [...]
> >>> And remember, the devil is in details. How are you going to assign
> >>> (initialize) that innocent looking "cur_adap_nr->hwadapnr"? How are you
> >>> going to work on an adapter other that "current" in a situation when you can
> >>> NOT change "current" adapter (e.g. perform all I2C layer initialization
> >>> while still running from flash?) Remember, this is plain C and there is no
> >> What makes you insist that we cannot change a variable if we need to
> >> be able to change one?
> > 
> > It is NOT just variable. My approach uses i2c _BUS_, not _ADAPTER_. And
> > number of busses can be bigger than number of adapters (e.g. when some
> > busses a reached via muxes or switches.) When doing i2c_set_current_bus()
> > you are switching _NOT_ adapters, but busses. That involves not only
> > changing that global variable but also reprogramming muxes/switches for
> > i2c_set_current_bus() to be consistent and hardware independent. Otherwise
> 
> You have no i2c_set_current_bus() in your code! I think you mean
> i2c_set_current_bus(), right?
> 
> And this function fails when running from flash! So, how can you switch
> busses with your patches when running from flash?
> 
> Here your function:
> 
> int i2c_set_bus_num(unsigned int bus)
> {
> #ifndef CONFIG_SYS_I2C_DIRECT_BUS
>         int             i;
>         u_int8_t        buf;
> #endif
> 
>         if ((bus >= CONFIG_SYS_NUM_I2C_BUSSES) || !(gd->flags & GD_FLG_RELOC))
>                 return(-1);
> [...]
> 
> This function wouldn;t work from flash ...

So what? I don't need that function to initialize adapters.

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