Re: [PATCH] OMAP: I2C driver for TI OMAP boards #3

[Jean Delvare <khali@linux-fr.org>]

Hi Tony, all,

On Thu, 10 Aug 2006 16:19:26 +0300, Tony Lindgren wrote:
> * Jean Delvare <khali@linux-fr.org> [060810 11:30]:
> > I've now taken Komal's patch (#4). Here is a proposed patch which brings
> > the prescaler computation formula in line with your comment and table
> > above. It could be applied on top of Komal's patch unless it causes a
> > problem on some of the OMAP systems. For XOR = 13 MHz, it changes the
> > prescaler from 0 to 1. For XOR = 19.2 MHz it changes the prescaler from
> > 2 to 1.
> 
> OK cool. As far as I'm concerned, I'm fine with it too:
> Signed-off-by: Tony Lindgren <tony@atomide.com>
>  
> > I don't have any hardware to test it, though. If it happens to be
> > better to be slightly over 12 MHz than slightly below 7 MHz, the
> > "> 12000000" condition below can be replaced with "> 14000000".
> 
> Thanks, we'll test it on various omaps and let you know if it works.

Any news on this? I still have this patch in my local tree. Should I
push it into Linux 2.6.20?

i2c: Fix OMAP clock prescaler to match the comment

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
---
 drivers/i2c/busses/i2c-omap.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- linux-2.6.18-rc4.orig/drivers/i2c/busses/i2c-omap.c	2006-08-10 09:56:54.000000000 +0200
+++ linux-2.6.18-rc4/drivers/i2c/busses/i2c-omap.c	2006-08-10 10:12:03.000000000 +0200
@@ -231,8 +231,8 @@
 		 * 13		2		1
 		 * 19.2		2		1
 		 */
-		if (fclk_rate > 16000000)
-			psc = (fclk_rate + 8000000) / 12000000;
+		if (fclk_rate > 12000000)
+			psc = fclk_rate / 12000000;
 	}
 
 	/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */


-- 
Jean Delvare