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2024-07-11i2c: pasemi: reword according to newest specificationWolfram Sang
Change the wording of this driver wrt. the newest I2C v7 and SMBus 3.2 specifications and replace "master/slave" with more appropriate terms. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Acked-by: Sven Peter <sven@svenpeter.dev> Reviewed-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
2024-02-14i2c: pasemi: split driver into two separate modulesArnd Bergmann
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: 9bc5f4f660ff ("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>
2022-11-12i2c: /pasemi: PASemi I2C controller IRQ enablementArminder Singh
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>
2022-04-15i2c: pasemi: Wait for write xfers to finishMartin Povišer
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: beb58aa39e6e ("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>
2022-02-15i2c: pasemi: Drop I2C classes from platform driver variantMartin Povišer
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: d88ae2932df0 ("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>
2021-10-11i2c: pasemi: Set enable bit for Apple variantSven Peter
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>
2021-10-11i2c: pasemi: Refactor _probe to use devm_*Sven Peter
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>
2021-10-11i2c: pasemi: Allow to configure bus frequencySven Peter
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>
2021-10-11i2c: pasemi: Move common reset code to own functionSven Peter
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>
2021-10-11i2c: pasemi: Split pci driver to its own fileSven Peter
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>