kernel/linux.git/drivers/base/soc.c, branch v4.14.78

base: soc: Allow early registration of a single SoC device

2017-03-29T19:43:26+00:00

Commit 1da1b3628df34a2a ("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 Acked-by: Arnd Bergmann

base: soc: Let soc_device_match() return no match when called too early

2017-03-29T19:43:22+00:00

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 Acked-by: Arnd Bergmann

base: soc: Check for NULL SoC device attributes

2016-11-10T09:10:33+00:00

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 Acked-by: Arnd Bergmann Acked-by: Greg Kroah-Hartman

base: soc: Introduce soc_device_match() interface

2016-11-10T09:10:29+00:00

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 Signed-off-by: Yangbo Lu Signed-off-by: Geert Uytterhoeven Acked-by: Greg Kroah-Hartman

base: soc: Early register bus when needed

2016-11-10T09:10:25+00:00

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 Acked-by: Arnd Bergmann

base: soc: make it explicitly non-modular

2016-08-31T13:13:56+00:00

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 Cc: Greg Kroah-Hartman Signed-off-by: Paul Gortmaker Signed-off-by: Greg Kroah-Hartman

base: soc: siplify ida usage

2015-10-04T18:42:22+00:00

Simplify ida index allocation and removal by using the ida_simple_* helper functions Signed-off-by: Lee Duncan Reviewed-by: Johannes Thumshirn Signed-off-by: Greg Kroah-Hartman

drivers/base: use tabs where possible in code indentation

2015-03-25T13:37:35+00:00

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 Signed-off-by: Greg Kroah-Hartman

mode_t whack-a-mole: ->is_visible() returns umode_t...

2012-05-30T03:28:42+00:00

Signed-off-by: Al Viro

drivers/base: fix compiler warning in SoC export driver - idr should be ida

2012-04-09T21:54:22+00:00

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 Cc: Greg Kroah-Hartman Signed-off-by: Lee Jones Signed-off-by: Axel Lin Acked-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman