My static checker complains that the ">" should be ">=" or else we go
beyond the end of the cb->irq_map[] array on the next line.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJason Cooper <jason@lakedaemon.net>

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: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-17-git-send-email-r.sricharan@ti.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

This is a basic check to ensure that crossbar register needs to be
written. This ensures that we have a common check which is used in
both map and unmap logic.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-15-git-send-email-r.sricharan@ti.comSigned-off-by: NJason 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: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-14-git-send-email-r.sricharan@ti.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Adding kerneldoc for unmap callback function.
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-13-git-send-email-r.sricharan@ti.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

If crossbar_of_init returns with a error, then set the cb pointer
to null.
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-12-git-send-email-r.sricharan@ti.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Using err1,2,3,4 etc makes it hard to ensure a new exit path in the
middle will not result in spurious changes, so rename the error paths
as per the function it does.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-11-git-send-email-r.sricharan@ti.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

crossbar_of_init always returns -ENOMEM in case of errors.
There can be other causes of failure like invalid data from
DT. So return a appropriate error value for that case.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-10-git-send-email-r.sricharan@ti.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Adding missing properties for kerneldoc (@write) and cleanup
of harmless warnings while we are here.

kerneldoc warnings:
Warning(drivers/irqchip/irq-crossbar.c:27): missing initial short description on line:
 * struct crossbar_device: crossbar device description
Info(drivers/irqchip/irq-crossbar.c:27): Scanning doc for struct
Warning(drivers/irqchip/irq-crossbar.c:39): No description found for parameter 'write'
2 warnings
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-9-git-send-email-r.sricharan@ti.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

There is absolutely no need for crossbar driver to expose functions and
variables into global namespace. So make them all static

Also fix a couple of checkpatch warnings.

Fixes sparse warnings:
drivers/irqchip/irq-crossbar.c:129:29: warning: symbol 'routable_irq_domain_ops' was not declared. Should it be static?
drivers/irqchip/irq-crossbar.c:261:12: warning: symbol 'irqcrossbar_init' was not declared. Should it be static?

Checkpatch warnings:
WARNING: Prefer kcalloc over kzalloc with multiply
+	cb->irq_map = kzalloc(max * sizeof(int), GFP_KERNEL);

WARNING: Prefer kcalloc over kzalloc with multiply
+	cb->register_offsets = kzalloc(max * sizeof(int), GFP_KERNEL);
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-8-git-send-email-r.sricharan@ti.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

IS_ERR_VALUE makes sense only *if* there could be valid values in
negative error range. But in the cases that we do use it, there is no
such case. Just remove the same.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-7-git-send-email-r.sricharan@ti.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Reverse the search algorithm to ensure that address mapping and IRQ
allocation logics are proper. This makes the below bugs visible sooner.

class 1. address space errors -> example:
reg = <a size_b>
ti,max-irqs =  is a wrong parameter

class 2: irq-reserved list - which decides which entries in the
address space is not actually wired in

class 3: wrong list of routable-irqs.

In general allocating from max to min tends to have benefits in
ensuring the different issues that may be present in dts is easily
caught at definition time, rather than at a later point in time.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-6-git-send-email-r.sricharan@ti.comSigned-off-by: NJason 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: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-5-git-send-email-r.sricharan@ti.comSigned-off-by: NJason 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: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-4-git-send-email-r.sricharan@ti.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

If irq_of_parse_and_map is executed twice, the same crossbar is mapped to two
different GIC interrupts. This is completely undesirable. Instead, check
if the requested crossbar event is pre-allocated and provide that GIC
mapping back to caller if already allocated.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-3-git-send-email-r.sricharan@ti.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Today '0' is actually reserved, but may not be the same in the future.

So, use a flag to mark the GIC interrupts that are reserved.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NSricharan R <r.sricharan@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-2-git-send-email-r.sricharan@ti.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

We are allocating the size of a pointer and not the size of the data.
This will lead to memory corruption.

There isn't actually a "cb_device" struct, btw.  The code is only able
to compile because GCC knows that all pointers are the same size.

Fixes: 96ca848e ('DRIVERS: IRQCHIP: CROSSBAR: Add support for Crossbar IP')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NSricharan R <r.sricharan@ti.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Link: http://lkml.kernel.org/r/20140403072134.GA14286@mwandaSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

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: NSricharan R <r.sricharan@ti.com>
Acked-by: Kumar Gala <galak@codeaurora.org> (for DT binding portion)
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>