Commit 1da1b3628d ("base: soc: Early register bus when needed")
added support for early registration of SoC devices from a
core_initcall(). However, some drivers need to check the SoC revision
from an early_initcall(), which is even earlier.
A specific example is the Renesas R-Car SYSC driver, which manages PM
Domains and thus needs to be initialized from an early_initcall.
Preproduction versions of the R-Car H3 SoC have an additional power
area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs
to check the exact SoC revision before instantiating a PM Domain for
that power area.
While registering the SoC bus and device, and using soc_device_match(),
from an early_initcall() do work, the "soc" directory and the "soc0"
file end up wrongly in the sysfs root, as the "bus" resp. "devices"
directories haven't been created yet.
To fix this, allow to register a single SoC device early on.
As long as the SoC bus isn't registered, soc_device_match() just
matches against this early device.
When the SoC bus is registered later, the early device is registered for
real.
Note that soc_device_register() returns NULL (no error, but also not a
valid pointer) when registering an early device. Hence platform devices
cannot be instantiated as children of the "soc0" node representing an
early SoC device. This should not be an issue, as that practice has
been deprecated for new platforms.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
If soc_device_match() is called before the SoC bus has been registered,
bus_for_each_dev() returns -EINVAL, which is considered a match, as it
is non-zero.
While calling soc_device_match() too early can be considered an
integration mistake, returning a match is counter-intuitive:
soc_device_match() is typically used to handle quirks, i.e. to deviate
from the default path. Hence add a check to abort checking and return
no match instead.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
If soc_device_match() is used to check the value of a specific
attribute that is not present for the current SoC, the kernel crashes
with a NULL pointer dereference.
Fix this by explicitly checking for the absence of a needed property,
and considering this a non-match.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We keep running into cases where device drivers want to know the exact
version of the a SoC they are currently running on. In the past, this has
usually been done through a vendor specific API that can be called by a
driver, or by directly accessing some kind of version register that is
not part of the device itself but that belongs to a global register area
of the chip.
Common reasons for doing this include:
- A machine is not using devicetree or similar for passing data about
on-chip devices, but just announces their presence using boot-time
platform devices, and the machine code itself does not care about the
revision.
- There is existing firmware or boot loaders with existing DT binaries
with generic compatible strings that do not identify the particular
revision of each device, but the driver knows which SoC revisions
include which part.
- A prerelease version of a chip has some quirks and we are using the same
version of the bootloader and the DT blob on both the prerelease and the
final version. An update of the DT binding seems inappropriate because
that would involve maintaining multiple copies of the dts and/or
bootloader.
This patch introduces the soc_device_match() interface that is meant to
work like of_match_node() but instead of identifying the version of a
device, it identifies the SoC itself using a vendor-agnostic interface.
Unlike of_match_node(), we do not do an exact string compare but instead
use glob_match() to allow wildcards in strings.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If soc_device_register() is called before soc_bus_register(), it crashes
with a NULL pointer dereference.
soc_bus_register() is already a core_initcall(), but drivers/base/ is
entered later than e.g. drivers/pinctrl/ and drivers/soc/. Hence there
are several subsystems that may need to know SoC revision information,
while it's not so easy to initialize the SoC bus even earlier using an
initcall.
To fix this, let soc_device_register() register the bus early if that
hasn't happened yet.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
The Kconfig currently controlling compilation of this code is:
drivers/base/Kconfig:config SOC_BUS
drivers/base/Kconfig: bool
...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.
Since module_init was not in use by this code, the init ordering
remains unchanged with this commit.
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Simplify ida index allocation and removal by
using the ida_simple_* helper functions
Signed-off-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel coding style require that tabs should be used instead of
spaces for code indentation.
Problem found using checkpatch.pl script.
Signed-off-by: Lavinia Tache <lavinia.tachee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This fixes:
note: expected ‘struct ida *’ but argument is of type ‘struct idr *’
warning: passing argument 1 of ‘ida_pre_get’ from incompatible pointer type
Reported-by: Arnd Bergman <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
soc_lock is already initialized by DEFINE_SPINLOCK.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Traditionally, any System-on-Chip based platform creates a flat list
of platform_devices directly under /sys/devices/platform.
In order to give these some better structure, this introduces a new
bus type for soc_devices that are registered with the new
soc_device_register() function. All devices that are on the same
chip should then be registered as child devices of the soc device.
The soc bus also exports a few standardised device attributes which
allow user space to query the specific type of soc.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
