Jochen Friedrich wrote:
Hi Wolfgang,
The I2C driver for the MPC currently uses a fixed speed hard-coded into
the driver. This patch adds the FDT properties "fdr" and "dfsrr" for the
corresponding I2C registers to make the speed configurable via FDT,
e.g.:
[EMAIL PROTECTED] {
compatible = "fsl-i2c";
reg = <0x3100 0x100>;
interrupts = <43 2>;
interrupt-parent = <&mpic>;
dfsrr = <0x20>;
fdr = <0x03>;
};
Would it be possible to use the standard property "clock-frequency" for this
and calculate the register settings in the driver?
Almost everything is possible in software, just for what price ;-).
U-Boot has some code in drivers/i2c/fsl_i2c.c to determine reasonable
fdr and dfsrr values for the MPC83/5/6xx boards. For the MPC82xx and
MPC85xx it's even more sophisticated.
I was also thinking to just overtake the U-Boot settings if fdt and
dfsrr is not defined for the I2C node (instead of the debatable default
values).
Wolfgang.
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