From: Domen Puncer <domen.puncer@telargo•com>
To: linuxppc-embedded@ozlabs•org
Subject: Re: Howto read I2C on MPC5200 Lite
Date: Thu, 15 Mar 2007 10:57:58 +0100 [thread overview]
Message-ID: <20070315095758.GE14658@moe.telargo.com> (raw)
In-Reply-To: <20070311005535.GA39488@server.idefix.lan>
On 11/03/07 01:55 +0100, Matthias Fechner wrote:
> Hi,
>
> * Matthias Fechner <idefix@fechner•net> [10-03-07 00:42]:
> > It seems now that everything works fine. I will check it for the next
> > days. And will give some feedback.
>
> ok, I checked now the driver some time at it failed. So it seems that
> that the patch had not solved the problem.
>
> I have attached the programm to check it.
But not for built-in eeprom :-P
Anyway, I managed to reproduce some problems, and hopefully "fix" them.
One problem seems to be fixed by disabling i2c on stop,
another looks like it's:
http://ozlabs.org/pipermail/linuxppc-embedded/2005-July/019038.html
Can you please try following patch.
Domen
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index ee65aa1..522f485 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -75,6 +75,20 @@ static irqreturn_t mpc_i2c_isr(int irq,
return IRQ_HANDLED;
}
+static void mpc_i2c_fixup(struct mpc_i2c *i2c)
+{
+ writeccr(i2c, 0);
+ udelay(30);
+ writeccr(i2c, CCR_MEN);
+ udelay(30);
+ writeccr(i2c, CCR_MSTA | CCR_MTX);
+ udelay(30);
+ writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN);
+ udelay(30);
+ writeccr(i2c, CCR_MEN);
+ udelay(30);
+}
+
static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
{
unsigned long orig_jiffies = jiffies;
@@ -154,6 +168,9 @@ static void mpc_i2c_start(struct mpc_i2c
static void mpc_i2c_stop(struct mpc_i2c *i2c)
{
writeccr(i2c, CCR_MEN);
+ mb();
+ writeccr(i2c, 0);
+ mb();
}
static int mpc_write(struct mpc_i2c *i2c, int target,
@@ -246,6 +263,8 @@ static int mpc_xfer(struct i2c_adapter *
}
if (time_after(jiffies, orig_jiffies + HZ)) {
pr_debug("I2C: timeout\n");
+ if (readb(i2c->base + MPC_I2C_SR) == (CSR_MCF | CSR_MBB | CSR_RXAK))
+ mpc_i2c_fixup(i2c);
return -EIO;
}
schedule();
next prev parent reply other threads:[~2007-03-15 9:58 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-07 12:24 Howto read I2C on MPC5200 Lite Matthias Fechner
2007-03-07 21:17 ` John Rigby
2007-03-09 11:35 ` Matthias Fechner
2007-03-09 17:11 ` John Rigby
2007-03-09 23:42 ` Matthias Fechner
2007-03-10 2:18 ` where and how to get the latest 2.6 kernel Nick Droogh
2007-03-11 1:01 ` Matthias Fechner
2007-03-11 0:55 ` Howto read I2C on MPC5200 Lite Matthias Fechner
2007-03-15 9:57 ` Domen Puncer [this message]
2007-03-16 4:33 ` Matthias Fechner
2007-03-17 8:57 ` Matthias Fechner
2007-03-18 19:06 ` Charles Krinke
2007-03-18 19:11 ` gdb question regarding step vs breakpoint Charles Krinke
2007-03-18 23:28 ` Matthias Fechner
2007-03-19 0:14 ` Howto read I2C on MPC5200 Lite Wolfgang Denk
2007-03-19 1:11 ` A question regarding step and breakpoints Charles Krinke
2007-03-21 8:34 ` Howto read I2C on MPC5200 Lite Matthias Fechner
2007-04-04 8:49 ` Domen Puncer
2007-04-25 18:48 ` Matthias Fechner
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