[U-Boot] MPC8572E I2C bus speed after emulator reset

[Timur Tabi]

Scott Coulter wrote:
> Hi Timur,
> 
>> What is the value of CONFIG_SYS_I2C_SPEED in your board header file?
>  
> #define CONFIG_SYS_I2C_SPEED		400000

So far, so good.

>> What values does function set_i2c_bus_speed() in fsl_i2c.c program
>> into the FDR and DFSR registers?
> 
> According to my printfs and the emulator readback of the values, the
> code is putting a 0x6 into the FDR and a 0x1 into the DFSR.  These
> values appear to be identical with either a hard reset or an emulator
> reset.

According to the 8572E RM, the default values for DFSR and FDR are 0x10
and 0x00.  The values above represent, according to the table, a divider
of 768.  The RM also says that I2C clock is 1/2 CCB, so that means that
your CCB should be 400,000 * 768 * 2 = 614MHz.  Is that right?

-- 
Timur Tabi
Linux kernel developer at Freescale