| Age | Commit message (Collapse) | Author | Files | Lines |
|---|
|
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>
|
|
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>
|
|
Use 'unsigned int' and curly braces for 'else'.
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
Since the return value is not checked anyhow, we don't need to store it.
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
Those variables are immediately assigned a value afterwards.
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
Currently when a gpio is defined for battery presence it is only used in
the sbs_get_battery_presence_and_health function for 2 properties.
All other properties currently try to read data form the battery before
returning an error if not present. We should know in advance that no
data is going to returned.
As the driver tries multiple times to access a property, this prevents
a lot of smbus accesses, which had a significant effect on device boot-up.
As when the device is registered lots of property accesses are attempted
during boot.
If no gpio is used for presence detection no change in behaviour should
occur.
Signed-off-by: Phil Reid <preid@electromag.com.au>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
This adds smb alert support via the smbus_alert driver to generate
power_supply_changed notifications when either external power is
removed / applied or a battery inserted / removed.
Use the i2c alert callback to notify the attached battery driver that a
change has occurred.
Signed-off-by: Phil Reid <preid@electromag.com.au>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
This patch adds support for Smart Battery System Manager.
A SBSM is a device listening at I2C/SMBus address 0x0a and is capable of
communicating up to four I2C smart battery devices. All smart battery
devices are listening at address 0x0b, so the SBSM muliplexes between
them. The driver makes use of the I2C-Mux framework to allow smart
batteries to be bound via device tree, i.e. the sbs-battery driver.
Via sysfs interface the online state and charge type are presented. If
the driver is bound as ltc1760 (an implementation of a Dual Smart Battery
System Manager) the charge type can also be changed from trickle to fast.
Signed-off-by: Karl-Heinz Schneider <karl-heinz@schneider-inet.de>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
Andy Shevchenko
Hoan Tran
Wolfram Sang
Claudio Foellmi
Linus Walleij
Geert Uytterhoeven
Phil Reid
Karl-Heinz Schneider