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

[Igor Grinberg]

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

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.