For imx50-weim and imx6q-weim type of devices, there might a WEIM CS
space configuration register in General Purpose Register controller,
e.g. IOMUXC_GPR1 on i.MX6Q.

Depending on which configuration of the following 4 is chosen for given
system, IOMUXC_GPR1[11:0] should be set up as 05, 033, 0113 or 01111
correspondingly.

	CS0(128M) CS1(0M)  CS2(0M)  CS3(0M)
	CS0(64M)  CS1(64M) CS2(0M)  CS3(0M)
	CS0(64M)  CS1(32M) CS2(32M) CS3(0M)
	CS0(32M)  CS1(32M) CS2(32M) CS3(32M)

The patch creates a function for such type of devices, which scans
'ranges' property of WEIM node and build the GPR value incrementally.
Thus the WEIM CS GPR can be set up automatically at boot time.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Reviewed-by: NPhilippe De Muyter <phdm@macqel.be>
Tested-by: NPhilippe De Muyter <phdm@macqel.be>

This patch adds WEIM support for all i.MX CPUs supported by the kernel.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

The WEIM(Wireless External Interface Module) works like a bus.
You can attach many different devices on it, such as NOR, onenand.

In the case of i.MX6q-sabreauto, the NOR is connected to WEIM.

This patch also adds the devicetree binding document.
The driver only works when the devicetree is enabled.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Acked-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>