Hello Naveen,

Am 01.10.2013 08:19, schrieb Naveen Krishna Ch:
Hello Heiko,

On 1 October 2013 11:35, Heiko Schocher<h...@denx.de>  wrote:
Hello Naveen,

Am 30.09.2013 12:03, schrieb Naveen Krishna Ch:

Helo Heiko,

Thanks for timely reply.

On 30 September 2013 13:35, Heiko Schocher<h...@denx.de>   wrote:

Hello Naveen,

Am 30.09.2013 08:58, schrieb Naveen Krishna Chatradhi:

This patchset fixes few bugs in the existing s3c24x0.c code (standard
i2c)
and add support for High-speed i2c bus controller available on Exynos5
SoCs
from Samsung.

Exynos5250 channels [0 ~ 3] can configured for I2C contoller or
              new HSI2C controller
              channels [3 ~ 7] are standard I2C controller channels
Exynos5420 channels [0 ~ 3] are standard I2C controller channels and
              channels [4 ~ 10] are High-speed controller channels

Patchset:
1.  exynos: i2c: Fix i2c driver to handle NACKs properly
       Improvements and fixes from Vadim Bendebury for standard i2c calls

2.  exynos: i2c: Change FDT bus setup code to enumerate ports correctly
       FDT bus setup code from Simon Glass

3.  PATCH v5: i2c: s3c24xx: add hsi2c controller support
       High-speed controller register description and defines new i2c
read/write,
       probe and set_bus calls.

       This is been reviewed earlier at
       http://lists.denx.de/pipermail/u-boot/2013-May/153245.html
       Thanks for review and improvements from Vadim Bendebury.

Question:
4. RFC: samsung: i2c: Enable new CONFIG_SYS_I2C framework
I've tried to implement the new I2C multi bus framework in u-boot tree,
taking tegra-i2c.c as reference.
[...]
channel:
--0----1----2----3------4--------5---------6-------7--------8-------9-------10
controller: i2c, i2c, i2c, i2c, hsi2c, hsi2c, hsi2c, hsi2c, hsi2c, hsi2c,
hsi2c.
But the "i2c bus" command is showing the bus number according to the
"name"
string comparison.  Which seems wrong. Isn't it ??


Hmm.. you are right, seems that the compiler sorts them alphabetical ...
So, two ways:
- use another name, saying first a two digit for the channel ?
- or, use CONFIG_SYS_NUM_I2C_BUSES, CONFIG_SYS_I2C_DIRECT_BUS
   and CONFIG_SYS_I2C_BUSES as described in the README (grep
   for CONFIG_SYS_I2C_BUSES in include/configs and you will find
   some examples ...) and you can define, which adapter is on which
   i2c_bus number ...
Will try and implement it this way.

Ok.

c). What's the alternative for the
      board_i2c_init(), i2c_get_bus_num_fdt(), i2c_reset_port_fdt().
     "Functions to get the I2C bus number and reset I2C bus using FDT
node"

      I think, these functions are still needed.



Hmm.. that needs a general discussion, how to use fdt and i2c I think.

I would prefer a way (not really nowing, if it is possible for all
configurations) where, if using fdt, the DT gets parsed and the
availiable i2c buses gets created ... After that, "normal" i2c access
with i2c_set_bus_num(), i2c_read/write should be possible ... this is
currently not possible with the i2c framework, but should not be so hard
to do. Except the restriction, that it would not work in SPL case, or
before relocation for i2c buses announced through dt

once i2c_init_board() is done board_i2c_init() is not quite needed
using i2c_init_board we can avoid the relocation problem aswell.

by the definition of i2c_get_bus_num() in drivers/i2c/i2c_core.c

unsigned int i2c_get_bus_num(void)
{
          return gd->cur_i2c_bus;
}

we don't need a special function i2c_get_bus_num_fdt()


Ah, ok!


IMHO, i2c_reset_port_fdt() is the only function to be discussed


And why is i2c_init() not good? Why must we have here a new function?
That's right, even if there is a need for  i2c_reset_port_fdt().
it must be a i2c-core function instead of being in a driver.


Define CONFIG_SYS_I2C_MAX_HOPS ->   CONFIG_SYS_I2C_DIRECT_BUS is not
defined
so i2c_bus[] is used in drivers/i2c/i2c_core.c. Define the fix i2c buses
in
the board config file with CONFIG_SYS_I2C_BUSES (if you have no fix
buses,
let this empty) and add a function in drivers/i2c/i2c_core.c, which adds
new i2c buses to i2c_bus[] after the fix buses and call this new
function,
from where you interpret the fdt ...

I din't quite understood this.
Can you point me to some readme or Doc or discussion Please.


just the U-Boot README ... The above was just a fast idea, how it
is possible to add i2c buses from the info in the fdt ...

Here some theoretical code, how it could look like:
[...]
Thanks for this explanation.

! It is just theoretical ... you must try it ;-)

And maybe here and there some adaptions for getting this running...
Thinking of i2c_set_bus_num(), there must be now a check for
i2c_fix_bus I think ...

Adapt the README ...

And then, from the place where you interpret the fdt, call if
you have the information for one i2c bus, i2c_add_one_bus() ...

Not sure, if I overlooked here something ...

Will try and do this.
Mean while can we get the other 3 patches reviewed.
Patch 1: http://patchwork.ozlabs.org/patch/278933/

This patch seems good to me, added to u-boot-i2c.git
as it seems it is a bugfix.

Patch 2: http://patchwork.ozlabs.org/patch/278931/
Patch 3: http://patchwork.ozlabs.org/patch/278930/

Think, they are OK, but they go after the next release to mainline,
as we are close to the next release ...

They were tested without the change to the new i2c framework.

Thanks for your work!

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