Add BlueField I2C driver to offer master and slave support for
Mellanox BlueField SoCs. The driver implements an SMBus adapter
and interfaces to multiple busses that can be probed using both
ACPI and Device Tree infrastructures.

The driver supports several SMBus operations to transfer data
back and forth from/to various I2C devices. It is mainly intended
to be consumed by userspace tools and utilities, such as i2c-tools
and decode-dimms to collect memory module information.

On the other hand, the driver has a slave function to support,
among others, an IPMB interface that requires both master and
slave functions to handle transfers between the BlueField SoC
and a board management controllers (e.g., BMC).
Signed-off-by: Khalil Blaiech <kblaiech@mellanox.com>
Reviewed-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Add device tree bindings documentation for Mellanox BlueField
I2C SMBus controller.
Signed-off-by: Khalil Blaiech <kblaiech@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Merge tag 'at24-updates-for-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux into i2c/for-5.10

at24 updates for v5.10

- add support for masking sensitive data in VAIO EEPROMs
- set the nvmem TYPE to NVMEM_TYPE_EEPROM
- add support for the new 'label' property
- set the nvmem ID to NVMEM_DEVID_AUTO by default (for backward
  compatibility) or to NVMEM_DEVID_NONE if label is defined

By using the label property, a more descriptive name can be populated
for AT24 EEPROMs NVMEM device. Update the AT24 driver to check to see
if the label property is present and if so, use this as the name for
NVMEM device. Please note that when the 'label' property is present for
the AT24 EEPROM, we do not want the NVMEM driver to append the 'devid'
to the name and so the nvmem_config.id is initialised to
NVMEM_DEVID_NONE.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Add a label property for the AT24 EEPROM to allow a custom name to be
used for identifying the EEPROM on a board. This is useful when there
is more than one EEPROM present.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The AT24 EEPROM driver does not initialise the 'id' field of the
nvmem_config structure and because the entire structure is not
initialised, it ends up with a random value. This causes the NVMEM
driver to append the device 'devid' value to name of the NVMEM
device. Ideally for I2C devices such as the AT24 that already have a
unique name, we would not bother to append the 'devid'. However, given
that this has always been done for AT24 devices, we cannot remove the
'devid' as this will change the name of the userspace sysfs node for
the NVMEM device. Nonetheless we should ensure that the 'id' field of
the nvmem_config structure is initialised so that there is no chance of
a random value causes problems in the future. Therefore, set the NVMEM
config.id to NVMEM_DEVID_AUTO for AT24 EEPROMs so that the 'devid' is
always appended.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

This makes the driver code slightly easier to read.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ajay Gupta <ajayg@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Add PCI ID for the Intel Emmitsburg PCH iSMT SMBus controller.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Seth Heasley <seth.heasley@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Kernel doc validation script complains:

  CHECK   .../drivers/i2c/busses/i2c-ismt.c
.../i2c-ismt.c:182: warning: cannot understand function prototype: 'const struct pci_device_id ismt_ids[] = '
.../i2c-ismt.c:202: warning: Function parameter or member 'dev' not described in '__ismt_desc_dump'
.../i2c-ismt.c:202: warning: Function parameter or member 'desc' not described in '__ismt_desc_dump'
.../i2c-ismt.c:649: warning: cannot understand function prototype: 'const struct i2c_algorithm smbus_algorithm = '

Fix corresponding descriptions to make reader and kernel doc validator happy.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Seth Heasley <seth.heasley@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

CONFIG_OF is selected by CONFIG_MACH_INGENIC, therefore we don't need to
handle the case where Device Tree is not supported.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The I2C controller in the JZ4770 SoC seems to work the exact same as in
the JZ4780 SoC.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The I2C controller in the JZ4770 SoC seems to work the exact same as in
the JZ4780 SoC.

We could use "ingenic,jz4780-i2c" as a fallback string in the Device
Tree, but that would be awkward, since the JZ4780 is newer. Instead,
add a "ingenic,jz4770-i2c" string and use it as fallback for the
"ingenic,jz4780-i2c" string.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

clang static analyzer reports this problem

i2c-amd-mp2-plat.c:174:9: warning: Branch condition evaluates
  to a garbage value
        return err ? err : num;
               ^~~

err is not initialized, it depends on the being set in the
transfer loop which will not happen if num is 0.  Surveying
other master_xfer() implementations show all handle a 0 num.

Because returning 0 is expected, initialize err to 0.
Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Elie Morisse <syniurge@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and the error value gets printed.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

DMA usage is optional for the I2C driver. check for the -ENODEV
error in order to avoid displaying an error when no DMA
has been requested.
Cleaning up the error messages during probe, remove the additional
-EPROBE_DEFER within probe function since additional error message
doesn't give much more information than what is already reported
within the stm32_i2c_dma_request function.
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Slightly easier to read.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Switch to using the new API kobj_to_dev().
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The I2C core can now utilize a slave interface to handle SMBus
HostNotify events. Enable it in this driver.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Here is an I2C slave backend driver which allows to test some uncommon
functionalities of the I2C and SMBus world. Usually, you need specific
devices to test e.g. SMBus Host Notify and such. With this driver you
just need the slave interface of another I2C controller.

This initial version has testcases for multi-master and SMBus Host
Notify. Already planned but not yet implemented are SMBus Alert and
messages with I2C_M_RECV_LEN.

Please read the documentation for further details.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Name slave slots in order to ease code maintenance.
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and the error value gets printed.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and the error value gets printed.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and the error value gets printed.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

LOOP_TIMEOUT was only used back then because we didn't want to introduce
another constant. The timeout value can easily be a magnitude shorter
because the typical range is 3us - 8us. Refactor the code to use the
poll_timeout helper, use a specific timeout value and get rid of the
ugly LOOP_TIMEOUT constant.
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>

I2C doesn't define a timeout for bus busy, so an arbitrary value like
LOOP_TIMEOUT is not a good idea. Let's use the timeout value in struct
adapter which is meant for such cases and is user-configurable (via
IOCTL). To reduce the load, wait 10us instead of 1us which is good
enough for the slow frequencies used by I2C. Finally, use the
poll_timeout helper instead of open coding it.
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>

Rely on the core functions to implement the host-notify
protocol via the a I2C slave device.
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Set type as NVMEM_TYPE_EEPROM to expose this info via
sysfs:

$ cat /sys/bus/nvmem/devices/{DEVICE}/type
EEPROM
Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

SMBus Host-Notify protocol, from the adapter point of view
consist of receiving a message from a client, including the
client address and some other data.

It can be simply handled by creating a new slave device
and registering a callback performing the parsing of the
message received from the client.

This commit introduces two new core functions
  * i2c_new_slave_host_notify_device
  * i2c_free_slave_host_notify_device
that take care of registration of the new slave device and
callback and will call i2c_handle_smbus_host_notify once a
Host-Notify event is received.
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

SMBus is largely compatible with I2C but there are some specifics. In
case we need them on a bus, we can now use this new binding.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

dev_err_probe() can reduce code size, uniform error handling and record the
defer probe reason etc., use it to simplify the code.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Value of /sys/devices/platform/lis3lv02d/position when
    Horizontal:     (36,-108,-1152)
    Left elevated:  (-432,-126,-1062)
    Front elevated: (36,594,-936)
    Upside down:    (-126,-252,1098)
Signed-off-by: Jeffrey Lin <jeffrey@icurse.nl>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The i2c-rcar driver utilizes the Generic Reset Controller kernel
feature, so select the RESET_CONTROLLER option when the I2C_RCAR
option is selected with a Gen3 SoC.

Fixes: 2b16fd63 ("i2c: rcar: handle RXDMA HW behaviour on Gen3")
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Andy Lowe <andy_lowe@mentor.com>
[erosca: Add "if ARCH_RCAR_GEN3" per Wolfram's request]
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

I2C master operating in multimaster mode can get stuck
indefinitely if I2C start is detected on bus, but no master
has a transaction going.

This is a weakness in I2C standard, which defines no way
to recover, since all masters are indefinitely disallowed
from interrupting the currently operating master. A start
condition can be created for example by an electromagnetic
discharge applied near physical I2C lines. Or a already
operating master could get reset immediately after sending
a start.

If it is known during device tree creation that only a single
I2C master will be present on the bus, this deadlock of the
I2C bus could be avoided in the driver by ignoring the
bus_is_busy register of the xiic, since bus can never be
reserved by any other master.

This patch adds this support for detecting single-master flag
in device tree and when provided, improves I2C reliability by
ignoring the therefore unnecessary xiic bus_is_busy register.

Error can be reproduced by pulling I2C SDA -line temporarily low
by shorting it to ground, while linux I2C master is operating on
it using the xiic driver. The application using the bus will
start receiving linux error code 16: "Device or resource busy"
indefinitely:

kernel: pca953x 0-0020: failed writing register
app: Error writing file, error: 16

With multi-master disabled device will instead receive error
code 5: "I/O error" while SDA is grounded, but recover normal
operation once short is removed.

kernel: pca953x 0-0020: failed reading register
app: Error reading file, error: 5
Signed-off-by: Jaakko Laine <ext-jaakko.laine@vaisala.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

xiic_i2c struct alignment causes the struct to
take more space in memory than strictly required.
Move state -member to end of struct to get less
padding.
Signed-off-by: Jaakko Laine <ext-jaakko.laine@vaisala.com>
Suggested-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Alignment removed and replaced with 1 space only to
reduce need for future alignment changes affecting multiple
lines, when new variables are added.
Signed-off-by: Jaakko Laine <ext-jaakko.laine@vaisala.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The elegant code in at24_read() has the drawback that we now need
to make a copy of all parameters to pass them to the post-processing
callback function if there is one. Rewrite the loop in such a way that
the parameters are not modified, so saving them is no longer needed.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The default value for a config option defaults to 'n' so it doesn't need
to be set here.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
[jdelvare: found another one]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Pull powerpc fixes from Michael Ellerman:

 - Add perf support for emitting extended registers for power10.

 - A fix for CPU hotplug on pseries, where on large/loaded systems we
   may not wait long enough for the CPU to be offlined, leading to
   crashes.

 - Addition of a raw cputable entry for Power10, which is not required
   to boot, but is required to make our PMU setup work correctly in
   guests.

 - Three fixes for the recent changes on 32-bit Book3S to move modules
   into their own segment for strict RWX.

 - A fix for a recent change in our powernv PCI code that could lead to
   crashes.

 - A change to our perf interrupt accounting to avoid soft lockups when
   using some events, found by syzkaller.

 - A change in the way we handle power loss events from the hypervisor
   on pseries. We no longer immediately shut down if we're told we're
   running on a UPS.

 - A few other minor fixes.

Thanks to Alexey Kardashevskiy, Andreas Schwab, Aneesh Kumar K.V, Anju T
Sudhakar, Athira Rajeev, Christophe Leroy, Frederic Barrat, Greg Kurz,
Kajol Jain, Madhavan Srinivasan, Michael Neuling, Michael Roth,
Nageswara R Sastry, Oliver O'Halloran, Thiago Jung Bauermann,
Vaidyanathan Srinivasan, Vasant Hegde.

* tag 'powerpc-5.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/perf/hv-24x7: Move cpumask file to top folder of hv-24x7 driver
  powerpc/32s: Fix module loading failure when VMALLOC_END is over 0xf0000000
  powerpc/pseries: Do not initiate shutdown when system is running on UPS
  powerpc/perf: Fix soft lockups due to missed interrupt accounting
  powerpc/powernv/pci: Fix possible crash when releasing DMA resources
  powerpc/pseries/hotplug-cpu: wait indefinitely for vCPU death
  powerpc/32s: Fix is_module_segment() when MODULES_VADDR is defined
  powerpc/kasan: Fix KASAN_SHADOW_START on BOOK3S_32
  powerpc/fixmap: Fix the size of the early debug area
  powerpc/pkeys: Fix build error with PPC_MEM_KEYS disabled
  powerpc/kernel: Cleanup machine check function declarations
  powerpc: Add POWER10 raw mode cputable entry
  powerpc/perf: Add extended regs support for power10 platform
  powerpc/perf: Add support for outputting extended regs in perf intr_regs
  powerpc: Fix P10 PVR revision in /proc/cpuinfo for SMT4 cores

Pull x86 fix from Thomas Gleixner:
 "A single fix for x86 which removes the RDPID usage from the paranoid
  entry path and unconditionally uses LSL to retrieve the CPU number.

  RDPID depends on MSR_TSX_AUX. KVM has an optmization to avoid
  expensive MRS read/writes on VMENTER/EXIT. It caches the MSR values
  and restores them either when leaving the run loop, on preemption or
  when going out to user space. MSR_TSX_AUX is part of that lazy MSR
  set, so after writing the guest value and before the lazy restore any
  exception using the paranoid entry will read the guest value and use
  it as CPU number to retrieve the GSBASE value for the current CPU when
  FSGSBASE is enabled. As RDPID is only used in that particular entry
  path, there is no reason to burden VMENTER/EXIT with two extra MSR
  writes. Remove the RDPID optimization, which is not even backed by
  numbers from the paranoid entry path instead"

* tag 'x86-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry/64: Do not use RDPID in paranoid entry to accomodate KVM