Ensure the bus is free when we register the adapter. Before the SCL/SDA
wires were in an unknown state. It used to work because sending a byte
has a retry mechanism which was triggered if the bus was initially in a
non-free state. But the graceful way to do it is to initialize
correctly.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Alter the DaVinci GPIO recovery fetch to use descriptors
all the way down into the board files.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Tested-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
It's possible that i2c_mux_reg_probe_dt() could return -EPROBE_DEFER.
In that case, driver will request a probe deferral and an error
suggesting device tree parsing problem will be reported. This is
a pretty confusing information. Let's change the error handling,
so driver will be able to request probe deferral without logging
not related errors.
Signed-off-by: Tomasz Bachorski <tomasz.bachorski@nokia.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
This patch extends the current i2c-mux-pca954x driver and adds support for
a newer PCA984x family of the I2C switches and multiplexers from NXP.
Signed-off-by: Adrian Fiergolski <adrian.fiergolski@cern.ch>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Peter Rosin <peda@axentia.se>
<linux/of_gpio.h> is not used in this file, by
<linux/gpio/consumer.h> is.
Someone is just lucky with their implicit includes.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The port number shift is still hard-coded to 1 while it now depends
on the hardware.
Thankfully 0 is always 0 no matter how you shift it, so this was a
bug without consequences.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 0fe16195f891 ("i2c: piix4: Fix SMBus port selection for AMD Family 17h chips")
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
When converting to GPIOD, the GPIO directions of SCL/SDA have been
swapped. Fix it!
Fixes: ad36a27959cabb ("i2c: imx: switch to using gpiod for bus recovery gpios")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
platform_device_id are not supposed to change at runtime. All functions
working with platform_device_id provided by <linux/platform_device.h>
work with const platform_device_id. So mark the non-const structs as
const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This HW is prone to races, so it needs to setup new messages in irq
context. That means we can't alloc bounce buffers if a message buffer is
not DMA safe. So, in that case, simply fall back to PIO.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This ensures that we fall back to PIO if the message length is too small
for DMA being useful. Otherwise, we use DMA. A bounce buffer might be
applied by the helper if the original message buffer is not DMA safe.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
For all block commands, try to allocate a DMA safe buffer and mark it
accordingly. Only use the stack, if the buffers cannot be allocated.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Those two functions are very similar, the only differences are that one
needs the I2C_M_RD flag for its message while the other one needs the
buffer casted to drop the const. Introduce a generic helper which allows
to specify the flags (also needed later for DMA safe variants of these
calls) and let the casting be done in the inlining functions which are
now calling the new helper function.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
One helper checks if DMA is suitable and optionally creates a bounce
buffer, if not. The other function returns the bounce buffer and makes
sure the data is properly copied back to the message.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add fault injection capabilities to the i2c-gpio driver. When connected
to another I2C bus, it can create unusual states which the other I2C bus
master driver needs to handle. Only for debugging!
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
include/linux/i2c is to be deprecated. Move this platform_data to the
proper platform_data dir.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
The designware core and platform are built as separate modules.
Export i2c_dw_prepare_clk() so it can be used by the platform
driver.
Fixes: a34a0b6da22540d19e57 ("i2c: designware: move i2c_dw_plat_prepare_clk to common")
Signed-off-by: Phil Reid <preid@electromag.com.au>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The correct header to include for the gpiod interface is
<linux/gpio/consumer.h>.
Fixes: 3991c5c80beaf7eb9 ("i2c: Switch to using gpiod interface for gpio bus recovery")
Signed-off-by: Phil Reid <preid@electromag.com.au>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Currently when an error occurs devinfo is still allocated but is
unused when the error exit paths break out of the for-loop. Fix
this by kfree'ing devinfo to avoid the leak.
Detected by CoverityScan, CID#1416590 ("Resource Leak")
Fixes: 4124c4eba402 ("i2c: allow attaching IRQ resources to i2c_board_info")
Fixes: 0daaf99d8424 ("i2c: copy device properties when using i2c_register_board_info()")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
On Apollo Lake devices the BIOS does not set up IRQ routing for the i801
SMBUS controller IRQ, so we end up with dev->irq set to IRQ_NOTCONNECTED.
Detect this and do not try to use the irq in this case silencing:
i801_smbus 0000:00:1f.1: Failed to allocate irq -2147483648: -107
Cc: stable@vger.kernel.org
BugLink: https://communities.intel.com/thread/114759
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The datasheet was a bit vague, but after consultation with HW designers,
we came to the conclusion that we should set the SCP bit always when
dealing only with the ICE bit. A set SCP bit is ignored, and thus fine,
a cleared one may trigger STOP on the bus.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We initiate STOP (or REP_START) on the second last WAIT interrupt
currently. This works fine but is not according to the datasheet which
says to do it on the last WAIT interrupt. This also simplifies the code
quite a lot, so let's do it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
There is no data when the first WAIT interrupt arrives. No need to read
something then.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
No need to do it manually.
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We can use the ternary operator for easier reading.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
ICE bit is for resetting the module. Other bits don't matter then, so we
don't need to use the iic_set_clr() function but can use iic_wr().
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Those two functions are very short and only called once. The code
becomes easier to understand if the code is directly put into the main
xfer function.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
No need to clear the interrupt registers because right after that we
disable the IP core which will reload registers with their initial
values anyhow.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Following the documentation, we initialize the HW before each START in
start_ch(). No need to do the same in activate_ch().
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Remove all reference to code related to using integer based ids for
scl/sda gpio for bus recovery. All in tree drivers are now using the
gpio descriptors to specific the required gpios.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Change the driver to use the gpio descriptors for the bus recovery
information instead of the deprecated integer interface.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Reviewed-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Change the driver to use the gpio descriptors for the bus recovery
information instead of the deprecated integer interface.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch contains much input from Phil Reid and has been tested
on Intel/Altera Cyclone V SOC Hardware with Altera GPIO's for the
SCL and SDA GPIO's.
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Tim Sander <tim@krieglstein.org>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
For consistency with the rest of the file rename function and parameter to
be consistent with the reset of the common file.
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Move the i2c_dw_plat_prepare_clk funciton to common file in preparation
for its use also by the master driver.
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Currently the i2c gpio recovery code uses gpio integer interface
instead of the gpiod. This change switch the core code to use
the gpiod while still retaining compatibility with the gpio integer
interface. This will allow individual driver to be updated and tested
individual to switch to using the gpiod interface.
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
According to data sheet SCL timing parameters and DW_IC_CON SPEED mode
bits are not used when operating in slave mode.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Luis Oliveira <lolivei@synopsys.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull compat and uaccess updates from Al Viro:
- {get,put}_compat_sigset() series
- assorted compat ioctl stuff
- more set_fs() elimination
- a few more timespec64 conversions
- several removals of pointless access_ok() in places where it was
followed only by non-__ variants of primitives
* 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (24 commits)
coredump: call do_unlinkat directly instead of sys_unlink
fs: expose do_unlinkat for built-in callers
ext4: take handling of EXT4_IOC_GROUP_ADD into a helper, get rid of set_fs()
ipmi: get rid of pointless access_ok()
pi433: sanitize ioctl
cxlflash: get rid of pointless access_ok()
mtdchar: get rid of pointless access_ok()
r128: switch compat ioctls to drm_ioctl_kernel()
selection: get rid of field-by-field copyin
VT_RESIZEX: get rid of field-by-field copyin
i2c compat ioctls: move to ->compat_ioctl()
sched_rr_get_interval(): move compat to native, get rid of set_fs()
mips: switch to {get,put}_compat_sigset()
sparc: switch to {get,put}_compat_sigset()
s390: switch to {get,put}_compat_sigset()
ppc: switch to {get,put}_compat_sigset()
parisc: switch to {get,put}_compat_sigset()
get_compat_sigset()
get rid of {get,put}_compat_itimerspec()
io_getevents: Use timespec64 to represent timeouts
...
Pull i2c updates from Wolfram Sang:
"This contains two bigger than usual tree-wide changes this time. They
all have proper acks, caused no merge conflicts in linux-next where
they have been for a while. They are namely:
- to-gpiod conversion of the i2c-gpio driver and its users (touching
arch/* and drivers/mfd/*)
- adding a sbs-manager based on I2C core updates to SMBus alerts
(touching drivers/power/*)
Other notable changes:
- i2c_boardinfo can now carry a dev_name to be used when the device
is created. This is because some devices in ACPI world need fixed
names to find the regulators.
- the designware driver got a long discussed overhaul of its PM
handling. img-scb and davinci got PM support, too.
- at24 driver has way better OF support. And it has a new maintainer.
Thanks Bartosz for stepping up!
The rest is regular driver updates and fixes"
* 'i2c/for-4.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (55 commits)
ARM: sa1100: simpad: Correct I2C GPIO offsets
i2c: aspeed: Deassert reset in probe
eeprom: at24: Add OF device ID table
MAINTAINERS: new maintainer for AT24 driver
i2c: nuc900: remove platform_data, too
i2c: thunderx: Remove duplicate NULL check
i2c: taos-evm: Remove duplicate NULL check
i2c: Make i2c_unregister_device() NULL-aware
i2c: xgene-slimpro: Support v2
i2c: mpc: remove useless variable initialization
i2c: omap: Trigger bus recovery in lockup case
i2c: gpio: Add support for named gpios in DT
dt-bindings: i2c: i2c-gpio: Add support for named gpios
i2c: gpio: Local vars in probe
i2c: gpio: Augment all boardfiles to use open drain
i2c: gpio: Enforce open drain through gpiolib
gpio: Make it possible for consumers to enforce open drain
i2c: gpio: Convert to use descriptors
power: supply: sbs-message: fix some code style issues
power: supply: sbs-battery: remove unchecked return var
...
In order to use i2c from a cold boot, the i2c peripheral must be taken
out of reset. We request a shared reset controller each time a bus
driver is loaded, as the reset is shared between the 14 i2c buses.
On remove the reset is asserted, which only touches the hardware once
the last i2c bus is removed.
The reset is required as the I2C buses will not work without releasing
the reset. Previously the driver only worked with out of tree hacks
that released this reset before the driver was loaded. Update the
device tree bindings to reflect this.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since i2c_unregister_device() became NULL-aware we may remove duplicate
NULL check.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Since i2c_unregister_device() became NULL-aware we may remove duplicate
NULL check.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
It's a common pattern to be NULL-aware when freeing resources.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch supports xgene-slimpro-i2c v2 which uses the non-cachable memory
as the PCC shared memory.
Signed-off-by: Hoan Tran <hotran@apm.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
cppcheck rightfully says:
drivers/i2c/busses/i2c-mpc.c:329: style: Variable 'node' is reassigned a value before the old one has been used.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
A very conservative check for bus activity (to prevent interference
in multimaster setups) prevented the bus recovery methods from being
triggered in the case that SDA or SCL was stuck low.
This defeats the purpose of the recovery mechanism, which was introduced
for exactly this situation (a slave device keeping SDA pulled down).
Also added a check to make sure SDA is low before attempting recovery.
If SDA is not stuck low, recovery will not help, so we can skip it.
Note that bus lockups can persist across reboots. The only other options
are to reset or power cycle the offending slave device, and many i2c
slaves do not even have a reset pin.
If we see that one of the lines is low for the entire timeout duration,
we can actually be sure that there is no other master driving the bus.
It is therefore save for us to attempt a bus recovery.
Signed-off-by: Claudio Foellmi <claudio.foellmi@ergon.ch>
Tested-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
[wsa: fixed one return code to -EBUSY]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
