Re: [PATCH v5 2/2] i2c: sunxi: add P2WI (Push/Pull 2 Wire Interface) controller support

On Tuesday 10 June 2014 15:47:16 Boris BREZILLON wrote:

+config I2C_SUN6I_P2WI
+       tristate "Allwinner sun6i internal P2WI controller"
+       depends on ARCH_SUNXI
+       help
+         If you say yes to this option, support will be included for the
+         P2WI (Push/Pull 2 Wire Interface) controller embedded in some sunxi
+         SOCs.
+         The P2WI looks like an SMBus controller (which supports only byte
+         accesses), except that it only supports one slave device.
+         This interface is used to connect to specific PMIC devices (like the
+         AXP221).
+

Sorry for the stupid question, but why is this an i2c driver if the
hardware protocol is completely different?

I understand that a lot of devices can be driven using either spi or
i2c, and we have two sets of {directories,maintainers,bus_types,...}
for them. Your description sounds like this is a separate option
that isn't any closer to i2c than it is to spi.

Would it perhaps be better to expose it only as a regmap rather than
an i2c host?

	Arnd