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>
This adds support for using the "sda" and "scl" GPIOs in
device tree instead of anonymously using index 0 and 1 of
the "gpios" property.
We add a helper function to retrieve the GPIO descriptors
and some explicit error handling since the probe may have
to be deferred. At least this happened to me when moving
to using named "sda" and "scl" lines (all of a sudden this
started to probe before the GPIO driver) so we need to
gracefully defer probe when we ge -ENOENT in the error
pointer.
Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The current i2c-gpio DT bindings use a single unnamed "gpios" property
to refer to the SDA and SCL signal lines by index. This is error-prone
for the casual DT writer and reviewer, as one has to look up the order
in the DT bindings.
Fix this by amending the DT bindings to use two separate named gpios
properties, and deprecate the old unnamed variant.
Take this opportunity to clearly deprecate the "i2c-gpio,sda-open-drain"
and "i2c-gpio,scl-open-drain" flags as well. The commit describes
in detail what these flags actually mean, and why they should not be
used in new device trees.
Cc: devicetree@vger.kernel.org
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
[Augmented to what I and Rob would like]
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
By creating local variables for *dev and *np, the code become
much easier to read, in my opinion.
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
We now handle the open drain mode internally in the I2C GPIO
driver, but we will get warnings from the gpiolib that we
override the default mode of the line so it becomes open
drain.
We can fix all in-kernel users by simply passing the right
flag along in the descriptor table, and we already touched
all of these files in the series so let's just tidy it up.
Cc: Steven Miao <realmz6@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Wu, Aaron <Aaron.Wu@analog.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The I2C GPIO bitbang driver currently emulates open drain
behaviour by implementing what the gpiolib already does:
not actively driving the line high, instead setting it to
input.
This makes no sense. Use the new facility in gpiolib to
request the lines enforced into open drain mode, and let
the open drain emulation already present in the gpiolib
kick in and handle this.
As a bonus: if the GPIO driver in the back-end actually
supports open drain in hardware using the .set_config()
callback, it will be utilized. That's correct: we never
used that hardware feature before, instead relying on
emulating open drain even if the GPIO controller could
actually handle this for us.
Users will sometimes get messages like this:
gpio-485 (?): enforced open drain please flag it properly
in DT/ACPI DSDT/board file
gpio-486 (?): enforced open drain please flag it properly
in DT/ACPI DSDT/board file
i2c-gpio gpio-i2c: using lines 485 (SDA) and 486 (SCL)
Which is completely proper: since the line is used as
open drain, it should actually be flagged properly with
e.g.
gpios = <&gpio0 5 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>,
<&gpio0 6 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
Or similar facilities in board file descriptor tables
or ACPI DSDT.
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Some busses, like I2C, strictly need to have the line handled
as open drain, i.e. not actively driven high. For this reason
the i2c-gpio.c bit-banged I2C driver is reimplementing open
drain handling outside of gpiolib.
This is not very optimal. Instead make it possible for a
consumer to explcitly express that the line must be handled
as open drain instead of allowing local hacks papering over
this issue.
The descriptor tables, whether DT, ACPI or board files, should
of course have flagged these lines as open drain. E.g.:
enum gpio_lookup_flags GPIO_OPEN_DRAIN for a board file, or
gpios = <&foo 42 GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN>; in a
device tree using <dt-bindings/gpio/gpio.h>
But more often than not, these descriptors are wrong. So
we need to make it possible for consumers to enforce this
open drain behaviour.
We now have two new enumerated GPIO descriptor config flags:
GPIOD_OUT_LOW_OPEN_DRAIN and GPIOD_OUT_HIGH_OPEN_DRAIN
that will set up the lined enforced as open drain as output
low or high, using open drain (if the driver supports it)
or using open drain emulation (setting the line as input
to drive it high) from the gpiolib core.
Cc: linux-gpio@vger.kernel.org
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This converts the GPIO-based I2C-driver to using GPIO
descriptors instead of the old global numberspace-based
GPIO interface. We:
- Convert the driver to unconditionally grab two GPIOs
from the device by index 0 (SDA) and 1 (SCL) which
will work fine with device tree and descriptor tables.
The existing device trees will continue to work just
like before, but without any roundtrip through the
global numberspace.
- Brutally convert all boardfiles still passing global
GPIOs by registering descriptor tables associated with
the devices instead so this driver does not need to keep
supporting passing any GPIO numbers as platform data.
There is no stepwise approach as elegant as this, I
strongly prefer this big hammer over any antsteps for this
conversion. This way the old GPIO numbers go away and
NEVER COME BACK.
Special conversion for the different boards utilizing
I2C-GPIO:
- EP93xx (arch/arm/mach-ep93xx): pretty straight forward as
all boards were using the same two GPIO lines, just define
these two in a lookup table for "i2c-gpio" and register
these along with the device. None of them define any
other platform data so just pass NULL as platform data.
This platform selects GPIOLIB so all should be smooth.
The pins appear on a gpiochip for bank "G" as pins 1 (SDA)
and 0 (SCL).
- IXP4 (arch/arm/mach-ixp4): descriptor tables have to
be registered for each board separately. They all use
"IXP4XX_GPIO_CHIP" so it is pretty straight forward.
Most board define no other platform data than SCL/SDA
so they can drop the #include of <linux/i2c-gpio.h> and
assign NULL to platform data.
The "goramo_mlr" (Goramo Multilink Router) board is a bit
worrisome: it implements its own I2C bit-banging in the
board file, and optionally registers an I2C serial port,
but claims the same GPIO lines for itself in the board file.
This is not going to work: there will be competition for the
GPIO lines, so delete the optional extra I2C bus instead, no
I2C devices are registered on it anyway, there are just hints
that it may contain an EEPROM that may be accessed from
userspace. This needs to be fixed up properly by the serial
clock using I2C emulation so drop a note in the code.
- KS8695 board acs5k (arch/arm/mach-ks8695/board-acs5.c)
has some platform data in addition to the pins so it needs to
be kept around sans GPIO lines. Its GPIO chip is named
"KS8695" and the arch selects GPIOLIB.
- PXA boards (arch/arm/mach-pxa/*) use some of the platform
data so it needs to be preserved here. The viper board even
registers two GPIO I2Cs. The gpiochip is named "gpio-pxa" and
the arch selects GPIOLIB.
- SA1100 Simpad (arch/arm/mach-sa1100/simpad.c) defines a GPIO
I2C bus, and the arch selects GPIOLIB.
- Blackfin boards (arch/blackfin/bf533 etc) for these I assume
their I2C GPIOs refer to the local gpiochip defined in
arch/blackfin/kernel/bfin_gpio.c names "BFIN-GPIO".
The arch selects GPIOLIB. The boards get spiked with
IF_ENABLED(I2C_GPIO) but that is a side effect of it
being like that already (I would just have Kconfig select
I2C_GPIO and get rid of them all.) I also delete any
platform data set to 0 as it will get that value anyway
from static declartions of platform data.
- The MIPS selects GPIOLIB and the Alchemy machine is using
two local GPIO chips, one of them has a GPIO I2C. We need
to adjust the local offset from the global number space here.
The ATH79 has a proper GPIO driver in drivers/gpio/gpio-ath79.c
and AFAICT the chip is named "ath79-gpio" and the PB44
PCF857x expander spawns from this on GPIO 1 and 0. The latter
board only use the platform data to specify pins so it can be
cut altogether after this.
- The MFD Silicon Motion SM501 is a special case. It dynamically
spawns an I2C bus off the MFD using sm501_create_subdev().
We use an approach to dynamically create a machine descriptor
table and attach this to the "SM501-LOW" or "SM501-HIGH"
gpiochip. We use chip-local offsets to grab the right lines.
We can get rid of two local static inline helpers as part
of this refactoring.
Cc: Steven Miao <realmz6@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Ben Dooks <ben.dooks@codethink.co.uk>
Cc: Heiko Schocher <hs@denx.de>
Acked-by: Wu, Aaron <Aaron.Wu@analog.com>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Move the check for a stuck SCL before the check for a high SDA.
This prevent false positives in the specific case that SDA is fine
and SCL is stuck, which previously returned 0.
Also check SDA again after the loop, if we can.
Together, these changes should lead to a lot more failed
recoveries being caught and returning error codes.
Signed-off-by: Claudio Foellmi <claudio.foellmi@ergon.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The i2c-img-scb driver already dynamically enables / disables clocks to
save power, but doesn't use the runtime PM framework. Convert the
driver to use runtime PM, so that dynamic clock management will be
disabled when runtime PM is disabled, and so that autosuspend can be
used to avoid unnecessarily disabling and re-enabling clocks repeatedly
during a sequence of transactions.
Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use of_property_read_bool to check for the existence of a property.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Remove the restriction that the parent clock has to be a specific frequency
and also allow any speed to be supported.
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add device-properties to make the bq24292i charger connected to
the bus get its input-current-limit from the fusb302 Type-C port
controller which is used on boards with the cht-wc PMIC,
as well as regulator_init_data for the 5V boost converter on
the bq24292i.
Since this means we now hook-up the bq24292i to the fusb302 Type-C port
controller add a check for the ACPI device which instantiates the fusb302.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
For devices not instantiated through ACPI the i2c-client's device-name
gets set to <busnr>-<addr> by default, e.g. "0-0022" this means that
the device-name is dependent on the order in which the i2c-busses are
enumerated.
In some cases having a predictable constant device-name is desirable,
for example on non device-tree platforms the link between a regulator
and its consumers is specified by the platform code by setting
regulator_init_data.consumers. This array identifies the regulator's
consumers by dev_name and supply(-name). Which requires a constant
dev_name.
This commit adds a dev_name field to i2c_board_info allowing
platform code to set a contstant dev_name so that the device can
be identified by its dev_name in other platform code.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mark Brown <broonie@kernel.org> (live at ELCE17)
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> (live at ELCE17)
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes this warning (found by build testing with 64bit):
format ‘%i’ expects argument of type ‘int’, but argument 3 has type
‘size_t {aka long unsigned int}’ [-Wformat=]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Pull staging and IIO fixes from Greg KH:
"Here are a small number of patches to resolve some reported IIO and a
staging driver problem. Nothing major here, full details are in the
shortlog below.
All have been in linux-next with no reported issues"
* tag 'staging-4.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: bcm2835-audio: Fix memory corruption
iio: adc: at91-sama5d2_adc: fix probe error on missing trigger property
iio: adc: dln2-adc: fix build error
iio: dummy: events: Add missing break
staging: iio: ade7759: fix signed extension bug on shift of a u8
iio: pressure: zpa2326: Remove always-true check which confuses gcc
iio: proximity: as3935: noise detection + threshold changes
Pull char/misc driver fixes from Greg KH:
"Here are four small fixes for 4.14-rc6.
Three of them are binder driver fixes for reported issues, and the
last one is a hyperv driver bugfix. Nothing major, but good fixes to
get into 4.14-final.
All of these have been in linux-next with no reported issues"
* tag 'char-misc-4.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
android: binder: Fix null ptr dereference in debug msg
android: binder: Don't get mm from task
vmbus: hvsock: add proper sync for vmbus_hvsock_device_unregister()
binder: call poll_wait() unconditionally.
Pull USB/PHY fixes from Greg KH:
"Here are a small number of USB and PHY driver fixes for 4.14-rc6
There is the usual musb and xhci fixes in here, as well as some needed
phy patches. Also is a nasty regression fix for usbfs that has started
to hit a lot of people using virtual machines.
All of these have been in linux-next with no reported problems"
* tag 'usb-4.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (26 commits)
usb: hub: Allow reset retry for USB2 devices on connect bounce
USB: core: fix out-of-bounds access bug in usb_get_bos_descriptor()
MAINTAINERS: fix git tree url for musb module
usb: quirks: add quirk for WORLDE MINI MIDI keyboard
usb: musb: sunxi: Explicitly release USB PHY on exit
usb: musb: Check for host-mode using is_host_active() on reset interrupt
usb: musb: musb_cppi41: Configure the number of channels for DA8xx
usb: musb: musb_cppi41: Fix cppi41_set_dma_mode() for DA8xx
usb: musb: musb_cppi41: Fix the address of teardown and autoreq registers
USB: musb: fix late external abort on suspend
USB: musb: fix session-bit runtime-PM quirk
usb: cdc_acm: Add quirk for Elatec TWN3
USB: devio: Revert "USB: devio: Don't corrupt user memory"
usb: xhci: Handle error condition in xhci_stop_device()
usb: xhci: Reset halted endpoint if trb is noop
xhci: Cleanup current_cmd in xhci_cleanup_command_queue()
xhci: Identify USB 3.1 capable hosts by their port protocol capability
USB: serial: metro-usb: add MS7820 device id
phy: rockchip-typec: Check for errors from tcphy_phy_init()
phy: rockchip-typec: Don't set the aux voltage swing to 400 mV
...
Wolfram Sang
Claudio Foellmi
Linus Walleij
Geert Uytterhoeven
Ed Blake
Julia Lawall
Chris Brandt
Kees Cook
Hans de Goede
Linus Torvalds