[U-Boot] [PATCH v2 2/3] Reset interrupted i2c slaves (galaxy5200)

[Eric Millbrandt]

Hi Heiko,

On Wed, 26 Aug 2009 08:57:46 +0200, Heiko Schocher wrote
> Hello Eric,
> 
> Eric Millbrandt wrote:
> > Reset any i2c devices that may have been interrupted by a system reset.
> > Normally this would be accomplished by clocking the line until SCL and SDA
> > are released and then sending a start condtiion (From an Atmel datasheet).
> > But since there is only write access to these lines on the MPC5200 we can
> > only attempt to reset any slave devices by sending more start commands than
> > bits the slave is attempting to transmit.
> > 
> > Signed-off-by: Eric Millbrandt <emillbrandt at dekaresearch.com>
> > ---
> > 
> > Changes since v1:
> > - Remove non-related modifications to a different patch per Peter's suggestion
> 
> one common comment:
> 
> Can you please use in_*/out_* accessors for accessing mpc52xx registers.

Ok.  I will do that.
> > 
> >  board/galaxy5200/galaxy5200.c |   41
+++++++++++++++++++++++++++++++++++++++++
> >  include/configs/galaxy5200.h  |    1 +
> >  2 files changed, 42 insertions(+), 0 deletions(-)
> > 
> > diff --git a/board/galaxy5200/galaxy5200.c b/board/galaxy5200/galaxy5200.c
> > index 5aa9d3a..c38e7de 100644
> > --- a/board/galaxy5200/galaxy5200.c
> > +++ b/board/galaxy5200/galaxy5200.c
> > @@ -155,6 +155,47 @@ phys_size_t initdram(int board_type)
> >  	return dramsize + dramsize2;
> >  }
> >  
> > +/*
> > + * Reset any i2c devices that may have been interrupted by a system reset.
> > + * Normally this would be accomplished by clocking the line until SCL and SDA
> > + * are released and then sending a start condtiion (From an Atmel datasheet).
> > + * But since there is only write access to these lines on the MPC5200 we can
> > + * only attempt to reset any slave devices by sending more start commands
than
> > + * bits the slave is attempting to transmit.
> > + */
> > +int misc_init_f(void)
> 
> Hmm.. why in misc_init_f? Can you move this function to the mpc52xx i2c
> driver, and add this in a manner like the send_reset() function
> in drivers/i2c/soft_i2c.c? And call this send_reset() in the
> i2c_init() from the mpc52xx i2c driver. As I don;t know, if this
> is valid for all mpc52xx boards, it should be then also per
> CONFIG_SYS_* define selectable.

The i2c registers that I used are only on the MPC5200B, not the MPC5200.  I
put the reset function under misc_init_f for that reason.  Is adding a single
cpu dependent function appropriate for the entire cpu/5xxx family branch?  If
it is then I will move the reset function to the mpc5xxx i2c driver.

Thanks

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