From: Andre Schwarz <andre.schwarz@matrix-vision.de>
To: Timur Tabi <timur@freescale.com>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: i2c-mpc clocking scheme
Date: Thu, 27 Nov 2008 16:43:45 +0100 [thread overview]
Message-ID: <492EC031.9000802@matrix-vision.de> (raw)
In-Reply-To: <ed82fe3e0811270724t26d2a8e2v233143722eb8587f@mail.gmail.com>
Timur Tabi schrieb:
> On Thu, Nov 27, 2008 at 9:00 AM, Andre Schwarz
> <andre.schwarz@matrix-vision.de> wrote:
>
>> All,
>>
>> is anybody working on some improvements regarding configurable I2C
>> frequency inside the i2c-mpc driver ?
>>
>> If not - would anybody be intersted in getting this done, i.e.
>> configurable via device tree ?
>>
>
> Maybe I'm missing something, but U-Boot configures the I2C bus speed.
> It does this because the algorithm is specific to the SOC itself. For
> example, the 8544 is different from the 8548. It would be a mess to
> duplicate this code in the kernel.
>
>
You're right regarding U-Boot, but the i2c-mpc driver overwrites the
"frequency divider register" on all chips.
I'm not happy with a fixed 0x3f @ MPC5200 which results in 65kHz ... :-(
Have a look at line 163 in drivers/i2c/busses/i2c-mpc.c
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next prev parent reply other threads:[~2008-11-27 15:43 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-27 15:00 i2c-mpc clocking scheme Andre Schwarz
2008-11-27 15:24 ` Timur Tabi
2008-11-27 15:43 ` Andre Schwarz [this message]
2008-11-28 20:59 ` Trent Piepho
2008-12-01 14:59 ` Timur Tabi
2008-12-01 19:40 ` André Schwarz
2008-12-01 19:48 ` Timur Tabi
2008-12-01 22:07 ` Trent Piepho
2008-12-01 22:26 ` Scott Wood
2008-12-01 22:57 ` Trent Piepho
2008-12-01 23:00 ` Timur Tabi
2008-12-01 23:07 ` Scott Wood
2008-11-27 15:49 ` Luotao Fu
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