On certain platforms such as DRA7, SPIs 0, 1, 2, 3, 5, 6, 10, 131,
132, 133 are direct wired to hardware blocks bypassing crossbar.
This quirky implementation is *NOT* supposed to be the expectation
of crossbar hardware usage. However, these are already marked in our
description of the hardware with SKIP and RESERVED where appropriate.
Unfortunately, we need to be able to refer to these hardwired IRQs.
So, to request these, crossbar driver can use the existing information
from it's table that these SKIP/RESERVED maps are direct wired sources
and generic allocation/programming of crossbar should be avoided.
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-17-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
The current crossbar description does not include the description
required for the consumer of the crossbar, a.k.a devices whoes events
pass through the crossbar into the GIC interrupt controller.
So, provide documentation for the same.
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-16-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Currently we attempt to map any crossbar value to an IRQ, however,
this is not correct from hardware perspective. There is a max crossbar
event number upto which hardware supports. So describe the same in
device tree using 'ti,max-crossbar-sources' property and use it to
validate requests.
[ jac - remove MAX_SOURCES from binding doc, use integer because we
shouldn't put implementation details in the binding docs ]
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-14-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Since crossbar is s/w configurable, the initial settings of the
crossbar cannot be assumed to be sane. This implies that:
a) On initialization all un-reserved crossbars must be initialized to
a known 'safe' value.
b) When unmapping the interrupt, the safe value must be written to
ensure that the crossbar mapping matches with interrupt controller
usage.
So provide a safe value in the dt data to map if
'0' is not safe for the platform and use it during init and unmap
While at this, fix the below checkpatch warning.
Fixes checkpatch warning:
WARNING: Unnecessary space before function pointer arguments
#37: FILE: drivers/irqchip/irq-crossbar.c:37:
+ void (*write) (int, int);
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-5-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
When, in the system due to varied reasons, interrupts might be unusable
due to hardware behavior, but register maps do exist, then those interrupts
should be skipped while mapping irq to crossbars.
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-4-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Some socs have a large number of interrupts requests to service
the needs of its many peripherals and subsystems. All of the
interrupt lines from the subsystems are not needed at the same
time, so they have to be muxed to the irq-controller appropriately.
In such places a interrupt controllers are preceded by an CROSSBAR
that provides flexibility in muxing the device requests to the controller
inputs.
This driver takes care a allocating a free irq and then configuring the
crossbar IP as a part of the mpu's irqchip callbacks. crossbar_init should
be called right before the irqchip_init, so that it is setup to handle the
irqchip callbacks.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Kumar Gala <galak@codeaurora.org> (for DT binding portion)
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
