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10 commits

Author SHA1 Message Date
Rob Herring
e9803aac50 mailbox: Explicitly include correct DT includes
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2023-09-05 10:10:58 -05:00
Conor Dooley
37e3430176 mailbox: mpfs: check the service status in .tx_done()
Services are supposed to generate an interrupt once completed, whether
or not they have do so successfully. What appears to be a bug in the
system controller means that interrupts are only generated for
*successful* services.

Currently, the status of a service is only checked in the
mpfs_mbox_rx_data() once an interrupt is received. As it turns out, this
is not really helpful where the potentially buggy behaviour is present,
as we'll only see the status for successes where it is moot anyway.

Jassi suggested moving the check to the .tx_done() callback instead.
This makes sense, as the busy bit that tx_done() is polling will be
lowered on completion, regardless of whether the service passed or
failed.
That allows us to check the status bits for all services, whether they
generate an interrupt or not & pass something more informative than
-EBADMSG back to the drivers implementing individual services.

Suggested-by: Jassi Brar <jassisinghbrar@gmail.com>
Acked-by: Jassi Brar <jaswinder.singh@linaro.org>
Tested-by: Valentina Fernandez <valentina.fernandezalanis@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2023-04-03 19:26:04 +01:00
Conor Dooley
da82f95f7c mailbox: mpfs: ditch a useless busy check
mpfs_mbox_rx_data() already checks if the system controller is busy
before attempting to do anything, so drop the second check before
reading any data.

No functional change intended.

Acked-by: Jassi Brar <jaswinder.singh@linaro.org>
Tested-by: Valentina Fernandez <valentina.fernandezalanis@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2023-04-03 19:25:52 +01:00
Conor Dooley
b5984a9844 mailbox: mpfs: switch to txdone_poll
The system controller on PolarFire SoC has no interrupt to signify that
the TX has been completed. The interrupt instead signals that a service
requested by the mailbox client has succeeded. If a service fails, there
will be no interrupt delivered.

Switch to polling the busy register to determine whether transmission
has completed.

Fixes: 83d7b15608 ("mbox: add polarfire soc system controller mailbox")
Acked-by: Jassi Brar <jaswinder.singh@linaro.org>
Tested-by: Valentina Fernandez <valentina.fernandezalanis@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2023-04-03 19:25:46 +01:00
Conor Dooley
75dfbcbfd7 mailbox: mpfs: fix an incorrect mask width
The system controller registers on PolarFire SoC are 32 bits wide, so
16 + 16 as the first input to GENMASK_ULL() gives a 33 bit wide mask.
It probably should have been immediately obvious when it was pointed
out during review that the width required using GENMASK_ULL() - but I
scarcely knew what I was doing at the time and missed it.
The mistake ends up being moot as it is a mask after all, but it is
incorrect and should be fixed.

No functional change intended.

Acked-by: Jassi Brar <jaswinder.singh@linaro.org>
Tested-by: Valentina Fernandez <valentina.fernandezalanis@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2023-04-03 19:25:31 +01:00
Conor Dooley
ab47d0bfdf mailbox: mpfs: read the system controller's status
Some services explicitly return an error code in their response, but
others rely on the system controller to set a status in its status
register. The meaning of the bits varies based on what service is
requested, so pass it back up to the driver that requested the service
in the first place. The field in the message struct already existed, but
was unused until now.

If the system controller is busy, in which case we should never actually
be in the interrupt handler, or if the service fails the mailbox itself
should not be read. Callers should check the status before operating on
the response.

There's an existing, but unused, #define for the mailbox mask - but it
was incorrect. It was doing a GENMASK_ULL(32, 16) which should've just
been a GENMASK(31, 16), so fix that up and start using it.

Fixes: 83d7b15608 ("mbox: add polarfire soc system controller mailbox")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2022-12-18 20:40:30 -06:00
Conor Dooley
0d1aadfe10 mailbox: mpfs: account for mbox offsets while sending
The mailbox offset is not only used for receiving messages, but it is
also used by messages sent to the system controller by Linux that have a
payload, such as the "digital signature service". It is also overloaded
by certain other services (reprogramming of the FPGA fabric, see Link:)
to have a meaning other than the offset the system controller should
read from.
When the driver was written, no such services of the latter type were
in use & those of the former used an offset of zero so this has gone
un-noticed.

Link: https://www.microsemi.com/document-portal/doc_download/1245815-polarfire-fpga-and-polarfire-soc-fpga-system-services-user-guide # Section 5.2
Fixes: 83d7b15608 ("mbox: add polarfire soc system controller mailbox")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2022-10-05 21:48:38 -05:00
Conor Dooley
2e10289d1f mailbox: mpfs: fix handling of the reg property
The "data" region of the PolarFire SoC's system controller mailbox is
not one continuous register space - the system controller's QSPI sits
between the control and data registers. Split the "data" reg into two
parts: "data" & "control". Optionally get the "data" register address
from the 3rd reg property in the devicetree & fall back to using the
old base + MAILBOX_REG_OFFSET that the current code uses.

Fixes: 83d7b15608 ("mbox: add polarfire soc system controller mailbox")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2022-10-05 21:48:31 -05:00
Conor Dooley
f10b1fc016 mailbox: change mailbox-mpfs compatible string
The Polarfire SoC is currently using two different compatible string
prefixes. Fix this by changing "polarfire-soc-*" strings to "mpfs-*" in
its system controller in order to match the compatible string used in
the soc binding and device tree.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2022-01-11 23:47:33 -06:00
Conor Dooley
83d7b15608 mbox: add polarfire soc system controller mailbox
This driver adds support for the single mailbox channel of the MSS
system controller on the Microchip PolarFire SoC.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2021-06-26 12:06:48 -05:00