>>>>> "Andreas" == Andreas Larsson <andreas@xxxxxxxxxxx> writes: Hi, Andreas> The registers in the GRLIB port of the controller are 32-bit Andreas> and in big endian byte order. The PRELOW and PREHIGH registers Andreas> are merged into one register. The subsequent registers have Andreas> their offset decreased accordingly. Hence the register access Andreas> needs to be handled in a non-standard manner using custom Andreas> getreg and setreg functions. Andreas> @@ -257,6 +300,14 @@ static int ocores_i2c_of_probe(struct platform_device *pdev, Andreas> of_property_read_u32(pdev->dev.of_node, "reg-io-width", Andreas> &i2c->reg_io_width); Andreas> + Andreas> + if (of_device_is_compatible(pdev->dev.of_node, Andreas> + "aeroflexgaisler,i2cmst")) { Andreas> + dev_dbg(&pdev->dev, "GRLIB variant of i2c-ocores\n"); Andreas> + i2c->setreg = oc_setreg_grlib; Andreas> + i2c->getreg = oc_getreg_grlib; Andreas> + } Andreas> + Please also update the bindings documentation under Documentation/devicetree/bindings/i2c. With this core you need to add both aeroflexgaisler,i2cmst and opencores,i2c-ocores to the compatible property, but the grlib variant is NOT compatible with i2c-ocores, so that's not really nice. Adding a type define (TYPE_OCORES / TYPE_GRLIB) and a 2nd of_device_id entry with .data = TYPE_GRLIB, and then using that in the probe routine would be nicer. Have a look at i2c-at91.c for an example of a driver doing something like that. -- Bye, Peter Korsgaard -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html