[PATCHv2 2/3] ARM: mxs: cfa10049: Switch bus i2c1 to bitbanging

[Christoph G. Baumann]

Hello Alexandre,

> The ADCs connected to this bus have been experiencing some timeout
> issues when using the iMX28 i2c controller. Switching back to bitbanging
> solves this.

the chip errata for i.MX23(!) contains an issue (no 2727) with the I2C
controller that is also applicable for the i.MX28:

"
2727 I2C 9th Clock Pulse (ACK) not generated when RETAIN_CLOCK set.

Description:
When RETAIN_CLOCK is set, the ninth clock pulse (ACK) is not generated. However,
the SDA
line is read at the proper timing interval. If RETAIN_CLOCK is cleared, the
ninth clock pulse is
generated.
Also, the HW_I2C_VERSION register incorrectly states the version is 1.2. It
should be 1.3.

Workaround:
HW_I2C_CTRL1[ACK_MODE] has default value of 0. It should be set to 1 to enable
the fix for
this issue.
"
 


Regards
Christoph Baumann