From: Heiko Schocher <hs@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [MPC8379E-rdb] Question about master bus busy after enabling I2C.
Date: Mon, 05 Sep 2011 08:29:58 +0200 [thread overview]
Message-ID: <4E646C66.5080701@denx.de> (raw)
In-Reply-To: <SNT115-W52027BA6117FB3A1DDC9D1D2180@phx.gbl>
Hello shawn,
shawn Bai wrote:
> Hi, here is a question about I2C initialization.
>
> I2C driver of our own references i2c driver implemented in fsl_i2c.c
>
> The init flow is almost the same.
>
> After writing enable-bit MEN into i2c control register to enable I2C controler,
>
> sometimes, Bit 2 in i2c status, MBB bit, will be set, indicating i2c master bus busy.
>
> And this will cause wait4bus return with failing.
>
> Is there anyone around who used to face this question?
>
> Or is there any suggestion or advice anyway?
Try a look in u-boot/doc/I2C_Edge_Conditions. Maybe your I2C bus
is left in a blocked state, so try to deblock it. As for an example
look in
board/keymile/common/common.c
There is a deblock sequence also for MPC83xx, maybe this helps you.
bye,
Heiko
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
next prev parent reply other threads:[~2011-09-05 6:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-02 15:18 [U-Boot] [MPC8379E-rdb] Question about master bus busy after enabling I2C shawn Bai
2011-09-05 6:29 ` Heiko Schocher [this message]
2011-09-08 2:06 ` shawn Bai
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