Messages in this thread | | | Date | Wed, 17 Oct 2007 14:35:16 -0500 | From | Scott Wood <> | Subject | Re: [PATCH take2] [POWERPC] i2c: adds support for i2c bus on 8xx |
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Jochen Friedrich wrote: >>> diff --git a/arch/powerpc/boot/dts/mpc885ads.dts >>> b/arch/powerpc/boot/dts/mpc885ads.dts >>> index 8848e63..a526c02 100644 >>> --- a/arch/powerpc/boot/dts/mpc885ads.dts >>> +++ b/arch/powerpc/boot/dts/mpc885ads.dts >>> @@ -213,6 +213,15 @@ >>> fsl,cpm-command = <0080>; >>> linux,network-index = <2>; >>> }; >>> + >>> + i2c@860 { >>> + device_type = "i2c"; >>> >> >> No device_type. >> > > Why? Documentation/powerpc/booting-without-of.txt says for I2C interfaces > device_type is required and should be "i2c". Is this no longer true?
booting-without-of.txt should be changed.
>> Should be fsl,cpm-i2c. Is cpm2 i2c the same? If not, it should be >> fsl,cpm1-i2c. It's probably best to specify it anyway, along with >> fsl,mpc885-i2c. > > CPM2 i2c seems to be the same. However, i have no way to test this.
OK, let's make the compatible "fsl,mpc885-i2c", "fsl,cpm1-i2c", "fsl,cpm-i2c".
For now, match on the last one, but if any differences pop up, we have the more specific ones.
> I noticed cpm1_set_pin32, but this function don't seem to set the > odr register. Will this be added? Then it would be: > > {CPM_PORTB, 26, CPM_PIN_OUTPUT | CPM_PIN_OPENDRAIN}, > {CPM_PORTB, 27, CPM_PIN_OUTPUT | CPM_PIN_OPENDRAIN}, >
Ah, missed that -- there's opendrain support for port E, but I missed that port B had it as well. Feel free to add it.
>> It's a 7-bit address... and are you sure that 0x7e is unique? Does this >> driver even support slave operation? > > It's in fact 0x7F << 1.
Gah, I hate powerpc bit numbering, especially without the numbered-as-if-64-bit hack. I specifically looked at the manual before to see if it was shifted, saw "0-6", and concluded it wasn't. :-P
> The same value is used in the 2.4 driver and > in u-boot, as well.
That doesn't mean that this isn't a good time to review what the code is doing. :-)
> Slave operation is not supported.
If slave operation isn't supported, how is this value used?
>> Why is an 8xx driver matching all i2c cpm (i.e. what about cpm2)? > > With the suggested change to use fsl,cpm-command, the driver should > be able to use both cpm1 and cpm2. The operation and structs for i2c > are identical. The only difference might be the hack^wsupport for > relocation.
OK. Would that allow it to become one driver, rather than a wrapper and an algorithm?
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