On powerpc, it is possible to compile test both the new apple (arm) and
old pasemi (powerpc) drivers for the i2c hardware at the same time,
which leads to a warning about linking the same object file twice:
scripts/Makefile.build:244: drivers/i2c/busses/Makefile: i2c-pasemi-core.o is added to multiple modules: i2c-apple i2c-pasemi
Rework the driver to have an explicit helper module, letting Kbuild
take care of whether this should be built-in or a loadable driver.
Fixes: 9bc5f4f660 ("i2c: pasemi: Split pci driver to its own file")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
This patch adds IRQ support to the PASemi I2C controller driver to
increase the performace of I2C transactions on platforms with PASemi I2C
controllers. While primarily intended for Apple silicon platforms, this
patch should also help in enabling IRQ support for older PASemi hardware
as well should the need arise.
This version of the patch has been tested on an M1 Ultra Mac Studio,
as well as an M1 MacBook Pro, and userspace launches successfully
while using the IRQ path for I2C transactions.
Signed-off-by: Arminder Singh <arminders208@outlook.com>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Reviewed-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Wait for completion of write transfers before returning from the driver.
At first sight it may seem advantageous to leave write transfers queued
for the controller to carry out on its own time, but there's a couple of
issues with it:
* Driver doesn't check for FIFO space.
* The queued writes can complete while the driver is in its I2C read
transfer path which means it will get confused by the raising of
XEN (the 'transaction ended' signal). This can cause a spurious
ENODATA error due to premature reading of the MRXFIFO register.
Adding the wait fixes some unreliability issues with the driver. There's
some efficiency cost to it (especially with pasemi_smb_waitready doing
its polling), but that will be alleviated once the driver receives
interrupt support.
Fixes: beb58aa39e ("i2c: PA Semi SMBus driver")
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Drop I2C device-probing classes from platform variant of the PASemi
controller as it is only used on platforms where I2C devices should
be instantiated in devicetree. (The I2C_CLASS_DEPRECATED flag is not
raised as up to this point no devices relied on the old behavior.)
Fixes: d88ae2932d ("i2c: pasemi: Add Apple platform driver")
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Acked-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Some later revisions after the original PASemi I2C controller introduce
what likely is an enable bit to the CTL register. Without setting it the
actual i2c transmission is never started.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Acked-by: Olof Johansson <olof@lixom.net>
Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Using managed device resources means there's nothing left to be done in
pasemi_smb_pci_remove and also allows to remove base and size from
struct pasemi_smbus.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Acked-by: Olof Johansson <olof@lixom.net>
Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Right now the bus frequency has always been hardcoded as
100 KHz with the specific reference clock used in the PASemi
PCI controllers. Make this configurable to prepare for the
platform driver.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Acked-by: Olof Johansson <olof@lixom.net>
Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Split out common reset call to its own function so that we
can later add support for selecting the clock frequency
and an additional enable bit found in newer revisions.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Acked-by: Olof Johansson <olof@lixom.net>
Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Split off the PCI driver so that we can reuse common code for the
platform driver.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Acked-by: Olof Johansson <olof@lixom.net>
Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2021-10-11 11:45:16 +02:00
Renamed from drivers/i2c/busses/i2c-pasemi.c (Browse further)
