[U-Boot] [PATCH 2/3] omap3evm: Update ethernet reset sequence for Rev.G board

[Premi, Sanjeev]

> -----Original Message-----
> From: Igor Grinberg [mailto:grinberg at compulab.co.il] 
> Sent: Monday, June 27, 2011 12:17 PM
> To: Premi, Sanjeev
> Cc: Govindarajan, Sriramakrishnan; u-boot at lists.denx.de
> Subject: Re: [U-Boot] [PATCH 2/3] omap3evm: Update ethernet 
> reset sequence for Rev.G board
> 
> On 06/27/11 08:06, Premi, Sanjeev wrote:
> 
> >> -----Original Message-----
> >> From: Premi, Sanjeev 
> >> Sent: Thursday, June 23, 2011 4:48 PM
> >> To: Premi, Sanjeev; Igor Grinberg
> >> Cc: Govindarajan, Sriramakrishnan; u-boot at lists.denx.de
> >> Subject: RE: [U-Boot] [PATCH 2/3] omap3evm: Update ethernet 
> >> reset sequence for Rev.G board
> >>
> >>> -----Original Message-----
> >>> From: u-boot-bounces at lists.denx.de 
> >>> [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Premi, Sanjeev
> >>> Sent: Thursday, June 23, 2011 4:43 PM
> >>> To: Igor Grinberg
> >>> Cc: Govindarajan, Sriramakrishnan; u-boot at lists.denx.de
> >>> Subject: Re: [U-Boot] [PATCH 2/3] omap3evm: Update ethernet 
> >>> reset sequence for Rev.G board
> >>>
> >>>> -----Original Message-----
> >>>> From: Igor Grinberg [mailto:grinberg at compulab.co.il] 
> >>>> Sent: Thursday, June 23, 2011 2:38 PM
> >>>> To: Premi, Sanjeev
> >>>> Cc: u-boot at lists.denx.de; Govindarajan, Sriramakrishnan
> >>>> Subject: Re: [U-Boot] [PATCH 2/3] omap3evm: Update ethernet 
> >>>> reset sequence for Rev.G board
> >>>>
> >>>> Hi Sanjeev,
> >>>>
> >>>> On 06/22/11 22:24, Sanjeev Premi wrote:
> >>>>> From: Sriramakrishnan <srk at ti.com>
> >>>>>
> >>>>> The GPIO pin used for resetting the external LAN chip has
> >>>>> changed for Rev.G board.
> >>>>>
> >>>>> Signed-off-by: Sriramakrishnan <srk at ti.com>
> >>>>> Signed-off-by: Sanjeev Premi <premi at ti.com>
> >>>>> ---
> >>>>>  board/ti/evm/evm.c |   27 ++++++++++++++++++---------
> >>>>>  1 files changed, 18 insertions(+), 9 deletions(-)
> >>>>>
> > [snip]...[snip]
> >
> >>>>> +	/* Send a pulse on the GPIO pin */
> >>>>> +	writel(pin, &gpio_base->setdataout);
> >>>>>  	udelay(1);
> >>>>> -	writel(GPIO0, &gpio3_base->cleardataout);
> >>>>> +	writel(pin, &gpio_base->cleardataout);
> >>>>>  	udelay(1);
> >>>>> -	writel(GPIO0, &gpio3_base->setdataout);
> >>>>> +	writel(pin, &gpio_base->setdataout);
> >>>> Why keep messing with the gpio registers?
> >>>> Why not use gpio framework?
> >>>> Though it is omap specific, but it will be much cleaner then 
> >>>> the above.
> >>> [sp] I guess the intent was to keep code similar. But yes,
> >>>      gpio framework can be used.
> >>>
> >> [sp] Sorry, mail went earlier than I wanted :(
> >>
> >>      The only issue is that I couln't see gpio framework for omap.
> >>      Let me dig further...
> >>
> > [sp] Implementing GPIO for OMAP would be a long task. It should be
> >      done for long term; but is it necessary pre-condition for the
> >      patch?
> 
> There is no need to implement GPIO for OMAP. It is already there,
> you just need to use it instead of writing directly to the 
> GPIO registers.
> You can find all the implementation in: 
> arch/arm/cpu/armv7/omap3/gpio.c
> and the header is: arch/arm/include/asm/arch-omap3/gpio.h

[sp] No wonder, I couldn't find it in drivers/gpio.
     (Didn't occur that it could be in ARCH specific dir)

     Will rebase and send an updated patch soon.

~sanjeev

> 
> All you need is to include the header, request the appropriate gpio,
> send the pulse and maybe (if you don't need it anymore) free 
> that gpio.
> This is not hard or long at all.
> 
> 
> 
> -- 
> Regards,
> Igor.
> 
>