soc: imx: Remove Layerscape check

Since commit 4ebd29f91629 ("soc: imx: Register SoC device only on i.MX
boards") the soc-imx driver is only registered on i.MX platforms as
intended.

This means that we no longer need to do a specific check for
Layerscape.

Remove the now unneeded "fsl,ls1021a" check.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

soc: imx: Register SoC device only on i.MX boards

At the moment, using the ARM32 multi_v7_defconfig always results in two
SoCs being exposed in sysfs. This is wrong, as far as I'm aware the
Qualcomm DragonBoard 410c does not actually make use of a i.MX SoC. :)

qcom-db410c:/sys/devices/soc0$ grep . *
family:Freescale i.MX
machine:Qualcomm Technologies, Inc. APQ 8016 SBC
revision:0.0
serial_number:0000000000000000
soc_id:Unknown

qcom-db410c:/sys/devices/soc1$ grep . *
family:Snapdragon
machine:APQ8016
...

This happens because imx_soc_device_init() registers the soc device
unconditionally, even when running on devices that do not make use of i.MX.
Arnd already reported this more than a year ago and even suggested a fix
similar to this commit, but for some reason it was never submitted.

Fix it by checking if the "__mxc_cpu_type" variable was actually
initialized by earlier platform code. On devices without i.MX it will
simply stay 0.

Cc: Peng Fan <peng.fan@nxp.com>
Fixes: d2199b34871b ("ARM: imx: use device_initcall for imx_soc_device_init")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/CAK8P3a0hxO1TmK6oOMQ70AHSWJnP_CAq57YMOutrxkSYNjFeuw@mail.gmail.com/
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

ARM: imx: Initialize SoC ID on i.MX50

As on i.MX51 and i.MX53, initialize the SoC ID based on the SoC
compatible string of the board.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

soc: imx: add i.MX51/i.MX53 unique id support

i.MX51 and i.MX53 SoCs have a 64-bit SoC unique ID stored in IIM,
which can be used as SoC serial number. The same feature is already
implemented for i.MX6/i.MX7, so this complements support to earlier
SoCs.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

soc: imx: check ls1021a

fsl,ls1021a is a mach under arch/arm/mach-imx/, however it could
not use the soc driver which will break caam on ls1021a platform.

So directly return if it is compatible with fsl,ls1021a.

Fixes: 52102a3ba6a61 ("soc: imx: move cpu code to drivers/soc/imx")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Tested-by: Horia Geantă <horia.geanta@nxp.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

soc: imx: move cpu code to drivers/soc/imx

Move the soc device register code to drivers/soc/imx to align with
i.MX8.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>