Hello Stephen,

On 29.10.2012 16:34, Stephen Warren wrote:
On 10/29/2012 03:47 AM, Heiko Schocher wrote:
Hello Stephen,

On 26.10.2012 18:07, Stephen Warren wrote:
On 10/25/2012 11:48 PM, Heiko Schocher wrote:
Hello Simon,

On 25.10.2012 23:37, Simon Glass wrote:
On Mon, Oct 22, 2012 at 10:40 AM, Heiko Schocher<h...@denx.de>    wrote:
[...]
That rather relies on their being a concept of a "current" I2C adapter.
It seems a little limiting to require that. What if the "current"
adapter is the user-selected adapter for commands to operate on, but
e.g. some power-management driver wants to use I2C to communicate with a
PMIC during the internals of some other command. Sure, you could save
and later restore the I2C core's idea of "current" adapter, but it'd
surely be cleaner to just pass around the I2C adapter ID or struct
pointer everywhere to avoid the need for save/restore.

Yes, you are right, but just the same problem with current code!
You mixed here two things!

I think you're reading more into what I was saying than what I actually
said.

Sorry, maybe I misunderstood you ...

If there are e.g. 4 I2C controllers in an SoC, the driver needs to know
which one is in use. Passing that information directly to the driver
functions is much simple than requiring the SoC I2C driver to go grovel
in some I2C core global variables to find out the same information.

Ah, do you mean we should change the i2c adapter struct from:

struct i2c_adapter {
       void            (*init)(int speed, int slaveaddr);
       int             (*probe)(uint8_t chip);
       int             (*read)(uint8_t chip, uint addr, int alen,
                               uint8_t *buffer, int len);
       int             (*write)(uint8_t chip, uint addr, int alen,
                               uint8_t *buffer, int len);
       uint            (*set_bus_speed)(uint speed);
[...]

to

struct i2c_adapter {
       void            (*init)(struct i2c_adapter *adap, int speed, int 
slaveaddr);
       int             (*probe)(struct i2c_adapter *adap, uint8_t chip);
       int             (*read)(struct i2c_adapter *adap, uint8_t chip, uint 
addr, int alen,
                               uint8_t *buffer, int len);
       int             (*write)(struct i2c_adapter *adap, uint8_t chip, uint 
addr, int alen,
                               uint8_t *buffer, int len);
       uint            (*set_bus_speed)(struct i2c_adapter *adap, uint speed);
[...]
?

We can do this. Simon suggested this too ...

@Simon: Is this Ok with you?

Nevertheless, we need a "cur_i2c_bus" pointer, as the i2c core, needs
to know the current i2c bus for detecting if the bus, which whould be
accessed is the current or not and a switching to another bus is needed.

This is all unrelated to I2C bus muxes; they shouldn't be implemented as
part of an SoC I2C driver anyway, so the driver shouldn't know about bus
muxes before or after this patch - the I2C core should manage that.

Exactly! And that do the new i2c framework in i2c_core.c!

bye,
Heiko
--
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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