This patch - finally, after over 6 months! :-( - addresses
Samuel's request to split the vexpress-sysreg driver into
smaller portions and define the device in a form of MFD
cells:
* LEDs code has been completely removed and replaced with
"gpio-leds" nodes in the tree (referencing dedicated
GPIO subnodes in sysreg - bindings documentation updated);
this also better fits the reality as some variants of the
motherboard don't have all the LEDs populated
* syscfg bridge code has been extracted into a separate
driver (placed in drivers/misc for no better place)
* all the ID & MISC registers are defined as sysconf
making them available for other drivers should they need
to use them (and also to the user via /sys/kernel/debug/regmap
which can be helpful in platform debugging)
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Components of the Versatile Express platform (configuration
microcontrollers on motherboard and daughterboards in particular)
talk to each other over a custom configuration bus. They
provide miscellaneous functions (from clock generator control
to energy sensors) which are represented as platform devices
(and Device Tree nodes). The transactions on the bus can
be generated by different "bridges" in the system, some
of which are universal for the whole platform (for the price
of high transfer latencies), others restricted to a subsystem
(but much faster).
Until now drivers for such functions were using custom "func"
API, which is being replaced in this patch by regmap calls.
This required:
* a rework (and move to drivers/bus directory, as suggested
by Samuel and Arnd) of the config bus core, which is much
simpler now and uses device model infrastructure (class)
to keep track of the bridges; non-DT case (soon to be
retired anyway) is simply covered by a special device
registration function
* the new config-bus driver also takes over device population,
so there is no need for special matching table for
of_platform_populate nor "simple-bus" hack in the arm64
model dtsi file (relevant bindings documentation has
been updated); this allows all the vexpress devices
fit into normal device model, making it possible
to remove plenty of early inits and other hacks in
the near future
* adaptation of the syscfg bridge implementation in the
sysreg driver, again making it much simpler; there is
a special case of the "energy" function spanning two
registers, where they should be both defined in the tree
now, but backward compatibility is maintained in the code
* modification of the relevant drivers:
* hwmon - just a straight-forward API change
* power/reset driver - API change
* regulator - API change plus error handling
simplification
* osc clock driver - this one required larger rework
in order to turn in into a standard platform driver
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Mark Brown <broonie@linaro.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Mike Turquette <mturquette@linaro.org>
This is a platform driver for Versatile Express' "system
register" block. It's a random collection of registers providing
the following functionality:
- low level platform functions like board ID access; in order to
use those, the driver must be initialized early, either statically
or based on the DT
- config bus bridge via "system control" interface; as the response
from the controller does not generate interrupt (yet), the status
register is periodically polled using a timer
- pseudo GPIO lines providing MMC card status and Flash WP#
signal control
- LED interface for a set of 8 LEDs on the motherboard, with
"heartbeat", "mmc0" and "cpu0" to "cpu5" as default triggers
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
