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Date: Fri, 28 May 2010 10:31:41 +0530
Message-ID: <AANLkTilv0sLE_ZO6B_BZiD34kAexkSi_ngawBoIje8jQ@mail.gmail.com>
Subject: Re: mylinux.list@gmail.com
From: Jack <mylinux.list@gmail.com>
To: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: linux-kernel@vger.kernel.org
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Hi,
Thanks,

First solution needs additional GPIO pins, I have used all the pins.
I'm going with the other solution, writing slave driver on the MIPS side.
The MIPS provides an interrupt vector for the I2C bus.

Regards,
Jack
.


On Thu, May 27, 2010 at 11:25 AM, Haojian Zhuang
<haojian.zhuang@gmail.com> wrote:
> On Thu, May 27, 2010 at 1:05 PM, linux_newbie good
> <mylinux.list@gmail.com> wrote:
>> Hi,
>>
>> My board has a MIPS based Processor and a micro-controller.  The
>> communication between these two interfaces is through an I2C bus. The
>> Linux driver for my I2C controller (i mean the one in MIPS processor)
>> has support for master transmitter and master receiver whereas I could
>> not find support for slave TX and slave RX modes. Do I need to write
>> my own functions for slave support? If so, what kind of changes need
>> to be done, for slave mode support? Is there any other sample driver
>> which can help ?
>>
>>
>
> Maybe you needn't write a slave I2C driver on MIPS side. It should
> based on your system requirement.
>
> I suggest the solution in below may be easier.
>
> ++++++++++++++                             ++++++++++++
> + MIPS (Master)  + -----> I2C -----------> + MCU (Slave)  +
> +                        +<----GPIO INT <----- +                     +
> ++++++++++++++                             ++++++++++++
>
> Since MIPS is master, it can read/write data from slave directly.
> While MCU want to contact with MIPS, it can trigger INT first. Then
> MIPS can query MCU and feed its required.
>
> Perhaps you may not choice this solution. You have to write slave
> driver on MIPS side and both master/slave driver on MCU side. You can
> refer to $LINUX/drivers/i2c/busses/i2c-pxa.c for reference. i2c-pxa
> driver supports both master and slave mode.
>
> Thanks
> Haojian
>