Dear Shawn Guo,

On Sun, Jun 10, 2012 at 01:53:05PM +0200, Marek Vasut wrote:

quoted

quoted

+struct mxs_i2c_speed_config {
+	uint32_t	timing0;
+	uint32_t	timing1;
+	uint32_t	timing2;
+};
+
+/* Timing values for the default 24MHz clock supplied into the i2c
block.

Thinking about these further -- does anyone have any idea how these
numbers were derived? And possibly even formula for that?

And maybe we should somehow make sure the source runs on 24MHz (how?).

There is nothing about I2C clock mentioned in CLKCTRL chapter.  I just
contacted design team and was told that I2C clock sources from APBX
(xbus) clock and always runs at the same frequency there.

Ok, then can you please try asking them how to exactly compute the values in 
timing0-timing2 registers? So we don't have to hardcode them like it's done now?

Best regards,
Marek Vasut