When i2c client unregisters, synchronize irq before setting
iproc_i2c->slave to NULL.

(1) disable_irq()
(2) Mask event enable bits in control reg
(3) Erase slave address (avoid further writes to rx fifo)
(4) Flush tx and rx FIFOs
(5) Clear pending event (interrupt) bits in status reg
(6) enable_irq()
(7) Set client pointer to NULL

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000318

[  371.020421] pc : bcm_iproc_i2c_isr+0x530/0x11f0
[  371.025098] lr : __handle_irq_event_percpu+0x6c/0x170
[  371.030309] sp : ffff800010003e40
[  371.033727] x29: ffff800010003e40 x28: 0000000000000060
[  371.039206] x27: ffff800010ca9de0 x26: ffff800010f895df
[  371.044686] x25: ffff800010f18888 x24: ffff0008f7ff3600
[  371.050165] x23: 0000000000000003 x22: 0000000001600000
[  371.055645] x21: ffff800010f18888 x20: 0000000001600000
[  371.061124] x19: ffff0008f726f080 x18: 0000000000000000
[  371.066603] x17: 0000000000000000 x16: 0000000000000000
[  371.072082] x15: 0000000000000000 x14: 0000000000000000
[  371.077561] x13: 0000000000000000 x12: 0000000000000001
[  371.083040] x11: 0000000000000000 x10: 0000000000000040
[  371.088519] x9 : ffff800010f317c8 x8 : ffff800010f317c0
[  371.093999] x7 : ffff0008f805b3b0 x6 : 0000000000000000
[  371.099478] x5 : ffff0008f7ff36a4 x4 : ffff8008ee43d000
[  371.104957] x3 : 0000000000000000 x2 : ffff8000107d64c0
[  371.110436] x1 : 00000000c00000af x0 : 0000000000000000

[  371.115916] Call trace:
[  371.118439]  bcm_iproc_i2c_isr+0x530/0x11f0
[  371.122754]  __handle_irq_event_percpu+0x6c/0x170
[  371.127606]  handle_irq_event_percpu+0x34/0x88
[  371.132189]  handle_irq_event+0x40/0x120
[  371.136234]  handle_fasteoi_irq+0xcc/0x1a0
[  371.140459]  generic_handle_irq+0x24/0x38
[  371.144594]  __handle_domain_irq+0x60/0xb8
[  371.148820]  gic_handle_irq+0xc0/0x158
[  371.152687]  el1_irq+0xb8/0x140
[  371.155927]  arch_cpu_idle+0x10/0x18
[  371.159615]  do_idle+0x204/0x290
[  371.162943]  cpu_startup_entry+0x24/0x60
[  371.166990]  rest_init+0xb0/0xbc
[  371.170322]  arch_call_rest_init+0xc/0x14
[  371.174458]  start_kernel+0x404/0x430

Fixes: c245d94e ("i2c: iproc: Add multi byte read-write support for slave mode")
Signed-off-by: Dhananjay Phadke <dphadke@linux.microsoft.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Ray Jui <ray.jui@broadcom.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Drivers using legacy power management .suspen()/.resume() callbacks
have to manage PCI states and device's PM states themselves. They also
need to take care of standard configuration registers.

Switch to generic power management framework using a single
"struct dev_pm_ops" variable to take the unnecessary load from the driver.
This also avoids the need for the driver to directly call most of the PCI
helper functions and device power state control functions, as through
the generic framework PCI Core takes care of the necessary operations,
and drivers are required to do only device-specific jobs.
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The driver calls pci_enable_wake(...., false) in pch_i2c_suspend() as well
as pch_i2c_resume(). Either it should enable-wake the device in .suspend()
or should not invoke pci_enable_wake() at all.

Concluding that this driver doesn't support enable-wake and PCI core calls
pci_enable_wake(pci_dev, PCI_D0, false) during resume, drop it from
.suspend() and .resume().
Reported-by: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The struct i2c_spec_values have it's members documented but is
missing the starting '@', which leads to warings like:

drivers/i2c/busses/i2c-mt65xx.c:267: warning: Function parameter or member 'min_low_ns' not described in 'i2c_spec_values'

We also delete min_high_ns member as it is not used in the code.
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Reviewed-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Add i2c compatible for MT8192. Compare to MT8183 i2c controller,
MT8192 support more then 8GB DMA mode.
Signed-off-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Add a DT binding documentation for the MT8192 soc.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Newer MTK chip support more than 8GB of dram. Replace support_33bits
with more general dma_max_support and remove mtk_i2c_set_4g_mode.
Reviewed-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
Signed-off-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

With the apdma remove hand-shake signal, it need to keep i2c and
apdma in sync manually.
Reviewed-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Add SMBus PCI ID on Intel Tiger Lake PCH-H.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Add support for SMBus controller on Intel Emmitsburg PCH. This is the
same IP as used in Cannon Lake and derivatives.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
[wsa: shortened commit message]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

And it has been for a while (since 2012 at least), only it was not
documented. Add it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Make the Microchip at91 driver the first to use the generic GPIO bus
recovery support from the I2C core and discard the driver implementation.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Even if I2C bus GPIO recovery is optional, devm_gpiod_get() can return
-EPROBE_DEFER, so we should at least treat that. This ends up with
i2c_register_adapter() to be able to return -EPROBE_DEFER.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Multiple I2C bus drivers use similar bindings to obtain information needed
for I2C recovery. For example, for platforms using device-tree, the
properties look something like this:

&i2c {
	...
	pinctrl-names = "default", "gpio";
	pinctrl-0 = <&pinctrl_i2c_default>;
	pinctrl-1 = <&pinctrl_i2c_gpio>;
	sda-gpios = <&pio 0 GPIO_ACTIVE_HIGH>;
	scl-gpios = <&pio 1 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
	...
}

For this reason, we can add this common initialization in the core. This
way, other I2C bus drivers will be able to support GPIO recovery just by
providing a pointer to platform's pinctrl and calling i2c_recover_bus()
when SDA is stuck low.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
[wsa: inverted one logic for better readability, minor update to kdoc]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The I2C GPIO bus recovery properties consist of two GPIOS and one extra
pinctrl state ("gpio" or "recovery"). "recovery" pinctrl state is
considered deprecated and "gpio" should be used instead.
Not all are mandatory for recovery.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Reviewed-by: Rob Herring <robh@kernel.org>
[wsa: kept sorting, minor whitespace change]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Due to the lockless design of the driver, it is theoretically possible
to access a NULL pointer, if a slave interrupt was running while we were
unregistering the slave. To make this rock solid, disable the interrupt
for a short time while we are clearing the interrupt_enable register.
This patch is purely based on code inspection. The OOPS is super-hard to
trigger because clearing SAR (the address) makes interrupts even more
unlikely to happen as well. While here, reinit SCR to SDBS because this
bit should always be set according to documentation. There is no effect,
though, because the interface is disabled.

Fixes: 7b814d85 ("i2c: rcar: avoid race when unregistering slave client")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

VI I2C is on host1x bus so APB DMA can't be used for Tegra210 VI
I2C and there are no tx and rx dma channels for VI I2C.

So, avoid attempt of requesting DMA channels.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

VI I2C is on host1x bus and is part of VE power domain.

During suspend/resume VE power domain goes through power off/on.

So, controller reset followed by i2c re-initialization is required
after the domain power up.

This patch fixes it.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

tegra_i2c_runtime_resume does not disable prior enabled clocks
properly.

This patch fixes it.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

clk_enable, clk_disable, clk_prepare, and clk_unprepare APIs have
implementation for checking clk pointer not NULL and clock consumers
can safely call these APIs without NULL pointer check.

So, this patch cleans up Tegra i2c driver to remove explicit checks
before these APIs.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Tegra VI I2C is part of VE power domain and typically used for
camera usecases.

VE power domain is not always on and is non-IRQ safe. So, IRQ safe
device cannot be attached to a non-IRQ safe domain as it prevents
powering off the PM domain and generic power domain driver will warn.

Current driver marks all I2C devices as IRQ safe and VI I2C device
does not require IRQ safe as it will not be used for atomic transfers.

This patch has fix to make VI I2C as non-IRQ safe.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Let's rather use its physical parent device to give proper namings and
connections in debugfs.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Merge tag 'kbuild-fixes-v5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild into master

Pull Kbuild fixes from Masahiro Yamada:

 - do not use non-portable strsep() in a host program

 - fix single target builds for external modules

 - change Clang's --prefix option to make it work for the latest Clang

* tag 'kbuild-fixes-v5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  Makefile: Fix GCC_TOOLCHAIN_DIR prefix for Clang cross compilation
  kbuild: fix single target builds for external modules
  modpost: remove use of non-standard strsep() in HOSTCC code

Merge branch 'parisc-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux into master

Pull parisc fixes from Helge Deller:
 "Two fixes:

   - Add the cmpxchg() function for pointers to u8 values. This fixes a
     kernel linking error when building the tusb1210 driver (from Liam
     Beguin).

   - Add a define for atomic64_set_release() to fix CPU soft lockups
     which happen because of missing unlocks while processing bit
     operations (from John David Anglin)"

* 'parisc-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Add atomic64_set_release() define to avoid CPU soft lockups
  parisc: add support for cmpxchg on u8 pointers

Merge tag 'char-misc-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc into master

Pull char/misc driver fixes from Greg KH:
 "Here are a few small driver fixes for 5.8-rc7

  They include:

   - habanalabs fixes

   - tiny fpga driver fixes

   - /dev/mem fixup from previous changes

   - interconnect driver fixes

   - binder fix

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  interconnect: msm8916: Fix buswidth of pcnoc_s nodes
  interconnect: Do not skip aggregation for disabled paths
  /dev/mem: Add missing memory barriers for devmem_inode
  binder: Don't use mmput() from shrinker function.
  habanalabs: prevent possible out-of-bounds array access
  fpga: dfl: fix bug in port reset handshake
  fpga: dfl: pci: reduce the scope of variable 'ret'
  habanalabs: set 4s timeout for message to device CPU
  habanalabs: set clock gating per engine
  habanalabs: block WREG_BULK packet on PDMA

Merge tag 'driver-core-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core into master

Pull driver core fix from Greg KH:
 "A single driver core fix for 5.8-rc7. It resolves a problem found in
  the previous fix for this code made in 5.8-rc6. Hopefully this is all
  now cleared up, as this seems to be the last of the reported issues in
  this area, and was tested on the problem hardware.

  This patch has been in linux-next with no reported problems"

* tag 'driver-core-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  device property: Avoid NULL pointer dereference in device_get_next_child_node()

Merge tag 'staging-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging into master

Pull staging driver fixes from Greg KH:
 "Five small staging driver fixes for 5.8-rc7 to resolve some reported
  problems:

   - four comedi driver fixes for problems found with them

   - a syzbot-found fix for the wlang-ng driver that resolves a much
     reported problem.

  All of these have been in linux-next with no reported issues"

* tag 'staging-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: wlan-ng: properly check endpoint types
  staging: comedi: addi_apci_1564: check INSN_CONFIG_DIGITAL_TRIG shift
  staging: comedi: addi_apci_1500: check INSN_CONFIG_DIGITAL_TRIG shift
  staging: comedi: addi_apci_1032: check INSN_CONFIG_DIGITAL_TRIG shift
  staging: comedi: ni_6527: fix INSN_CONFIG_DIGITAL_TRIG support

Pull tty/serial/fbcon fixes from Greg KH:
 "Here are some small tty and serial and fbcon fixes for 5.8-rc7 to
  resolve some reported issues.

  The fbcon fix is in here as it was simpler to take it this way (and it
  was acked by the maintainer) as it was related to the vt console fix
  as well, both of which resolve syzbot-found issues in the console
  handling code.

  The other serial driver fixes are for small issues reported in the -rc
  releases.

  All of these have been in linux-next with no reported issues"

* tag 'tty-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: exar: Fix GPIO configuration for Sealevel cards based on XR17V35X
  fbdev: Detect integer underflow at "struct fbcon_ops"->clear_margins.
  serial: 8250_mtk: Fix high-speed baud rates clamping
  serial: 8250: fix null-ptr-deref in serial8250_start_tx()
  serial: tegra: drop bogus NULL tty-port checks
  serial: tegra: fix CREAD handling for PIO
  tty: xilinx_uartps: Really fix id assignment
  vt: Reject zero-sized screen buffer size.

Pull USB fixes from Greg KH:
 "Three small USB XHCI driver fixes for 5.8-rc7.

  They all resolve some minor issues that have been reported on some
  different platforms.

  All of these have been in linux-next with no reported issues"

* tag 'usb-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: tegra: Fix allocation for the FPCI context
  usb: xhci: Fix ASM2142/ASM3142 DMA addressing
  usb: xhci-mtk: fix the failure of bandwidth allocation

Pull SCSI fix from James Bottomley:
 "Small core patch to fix a corner case bug: we forgot to run the queues
  to handle starvation in the error exit from the scsi_queue_rq routine,
  which can lead to hangs on error conditions"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: core: Run queue in case of I/O resource contention failure

Document IIC controller for RZ/G2H (R8A774E1) SoC, which is compatible
with R-Car Gen3 SoC family.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Document i2c controller for RZ/G2H (R8A774E1) SoC, which is compatible
with R-Car Gen3 SoC family.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

When the SSR interrupt is activated, it will detect every STOP condition
on the bus, not only the ones after we have been addressed. So, enable
this interrupt only after we have been addressed, and disable it
otherwise.

Fixes: de20d185 ("i2c: rcar: add slave support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Merge tag 'riscv-for-linus-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux into master

Pull RISC-V fixes from Palmer Dabbelt:
 "A few more fixes this week:

   - A fix to avoid using SBI calls during kasan initialization, as the
     SBI calls themselves have not been probed yet.

   - Three fixes related to systems with multiple memory regions"

* tag 'riscv-for-linus-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Parse all memory blocks to remove unusable memory
  RISC-V: Do not rely on initrd_start/end computed during early dt parsing
  RISC-V: Set maximum number of mapped pages correctly
  riscv: kasan: use local_tlb_flush_all() to avoid uninitialized __sbi_rfence

Merge tag 'x86-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull x86 fixes from Ingo Molnar:
 "Misc fixes:

   - Fix a section end page alignment assumption that was causing
     crashes

   - Fix ORC unwinding on freshly forked tasks which haven't executed
     yet and which have empty user task stacks

   - Fix the debug.exception-trace=1 sysctl dumping of user stacks,
     which was broken by recent maccess changes"

* tag 'x86-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/dumpstack: Dump user space code correctly again
  x86/stacktrace: Fix reliable check for empty user task stacks
  x86/unwind/orc: Fix ORC for newly forked tasks
  x86, vmlinux.lds: Page-align end of ..page_aligned sections

Merge tag 'perf-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull uprobe fix from Ingo Molnar:
 "Fix an interaction/regression between uprobes based shared library
  tracing & GDB"

* tag 'perf-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  uprobes: Change handle_swbp() to send SIGTRAP with si_code=SI_KERNEL, to fix GDB regression

Merge tag 'timers-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull timer fix from Ingo Molnar:
 "Fix a suspend/resume regression (crash) on TI AM3/AM4 SoC's"

* tag 'timers-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/timer-ti-dm: Fix suspend and resume for am3 and am4