Don't use a property to set a value in the front end that can simply
be set directly in the softc instead.

As with ACPI, perform the fdtbus_register_i2c_controller() in a centralized
location.

Garbage-collect fdtbus_attach_i2cbus(); the regular iicbus_attach() is
sufficient now.

branches: 1.17.4; 1.17.14;
Rename of_match_compat_data() to of_compatible_match(). Similarly,
rename of_search_compatible() to of_compatible_lookup().

Standardize on of_compatible_match() for driver matching, and adapt
all call sites.

Use DEVICE_COMPAT_EOL.

Since we're using designated initialisers for compat data, we should
use a completely empty initializer for the sentinel.

Remove "struct of_compat_data" and replace its usage with
"struct device_compatible_entry"; they are ABI-compatible.

Fix several "loses const qualifier" bugs encountered during
this conversion.

use fdtbus_intr_establish_xname

Change fdtbus_register_i2c_controller() to directly register the i2c_tag_t,
rather than the device and a set of functions (the only of which was to
return the i2c_tag_t anyway). Previously, this assumed only a single
i2c controller node per device_t, which is not true with an i2c mux.

branches: 1.11.6;
Clean up gttwsi's register access stuff:
- Garbage-collect the obsolete GTTWSI_ALLWINNER option; it hasn't been
needed since FDT'ization of the Allwinner support code.
- Redefine thw "TWSI_*" register definitions to clearly call out:
-> The Marvell flavor of the offsets
-> The Allwinner flavor of the offsets
...and make the regular definitions indices into a register map.
- Pass the appropriate register map from the front-end to the core.
- Remove the customer register read/write callbacks -- they are no longer
needed now that each front-end passes an appropriate register map to
the core.

branches: 1.10.6;
Use fdtbus_attach_i2cbus

branches: 1.9.2;
If we don't get informed (via device properties) of child I2C devices,
don't assign an empty array to iba.iba_child_devices, as it will prevent
indirect configuration of the I2C bus from occurring.

Tested on Raspberry Pi (bcm2835), identical logical fix replicated
(and compile-tested) elsewhere.

PR port-arm/53171

branches: 1.8.2; 1.8.4;
Support nodes w/o a defined clock.

Set twi clock based on parent clock, and fix register remapping for writes.

sunxi_twi: provide custom read/write reg callbacks and remove the
GTTWSI_ALLWINNER option from the kernel config

Initialize TWI clock rate to 100kHz

Set iflg-rwc for sun6i-a31 compatible devices.

branches: 1.3.2;
Add initial support for Allwinner A13 and R8 SoCs.

branches: 1.2.4;
Fix dmesg

Add i2c glue.