This errata occurs when the ARDY interrupt generation is enabled.
At the begining of every new transaction the ARDY interrupt is cleared.
On continuous i2c transactions where after clearing the ARDY bit from
I2C_STAT register (clearing the interrupt), the IRQ line is reasserted and the
I2C_STAT[ARDY] bit set again on 1. In fact, the ARDY status bit is not cleared
at the write access to I2C_STAT[ARDY] and only the IRQ line is deasserted and
then reasserted. This is not captured in the usual errata documents.
The workaround is to have a double clear of ARDY status in irq handler.
Signed-off-by: Richard woodruff <r-woodruff2@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
When runtime PM is enabled, each OMAP i2c device is suspended after
each i2c xfer. However, there are two cases when the static suspend
methods must be used to ensure the devices are suspended:
1) runtime PM is disabled, either at compile time or dynamically
via /sys/devices/.../power/control.
2) an i2c client driver uses i2c during it's suspend callback, thus
leaving the i2c driver active (NOTE: runtime suspend transitions are
disabled during system suspend, so i2c activity during system
suspend will runtime resume the device, but not runtime (re)suspend it.)
Since the actual work to suspend the device is handled by the
subsytem, call the bus methods to take care of it.
NOTE: This takes care of a known suspend problem on OMAP3 where the
TWL RTC driver does i2c xfers during its suspend path leaving the i2c
driver in an active state (since runtime suspend transistions are
disabled.)
Signed-off-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Since the PM core wishes to transition away from the legacy suspend
and resume methods and since removing them makes using PM core features
like runtime PM much easier start warning when a driver is registered
using the legacy methods.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
When devices use dev_pm_ops the I2C API is implementing standard functionality
for integration with runtime PM and for checking for the presence of a per
device op. The PM core provides pm_generic_ functions implementing this
behaviour - use them to reduce coupling with future PM updates.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Remove real devices first and dummy devices last. This gives device
driver which instantiated dummy devices themselves a chance to clean
them up before we do.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Hans Verkuil <hverkuil@xs4all.nl>
Cc: stable@kernel.org
The SCx200 ACB driver supports ISA hardware as well as PCI. The PCI
hardware is CS5535/CS5536 based, and the device that it grabs is handled by
the cs5535-mfd driver. This converts the SCx200 driver to use a
platform_driver rather than the previous PCI hackery.
The driver used to manually track the iface list (via linked list); now it
only does this for ISA devices. PCI ifaces are handled through standard
driver model lists.
It's unclear what happens in case of errors in the old ISA code; rather than
pretending the code actually cares, I've dropped the (implicit) ignorance
of return values and marked it with a comment.
Signed-off-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* 'for-linus/i2c-2638' of git://git.fluff.org/bjdooks/linux:
i2c-bfin-twi: move setup to the earlier subsys initcall
i2c-bfin-twi: handle faulty slave devices better
i2c-mv64xxx: send repeated START between messages in xfer
i2c-nomadik: fix regression on adapter name
i2c-omap: Set latency requirements only once for several messages
i2c-eg20t: add driver for Intel EG20T
i2c-ocores: add some device tree documentation
i2c-ocores: Use devres for resource allocation
i2c-ocores: Adapt for device tree
i2c-iop3xx: add iomem annotation
Some systems using this bus sometimes have very basic devices such as
regulators on the bus, so the I2C bus master needs to be loaded early.
This also matches the behavior of many other I2C bus master drivers.
Therefore initialize via subsys_initcall().
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Faulty slave devices might drive SDA low after a transfer finishes. So,
when this scenario is detected, have the master generate up to 9 extra
clocks until the SDA is properly released.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Helper functions for I2C and SMBus transactions don't modify the
i2c_client that is passed to them, so it can be marked const.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The I2C specification explicitly describes both SDA and SCL as
bidirectional lines. An I2C master with a read-only SCL is thus not
compliant. If a slow slave stretches the clock, errors will happen,
so the bus can't be considered as reliable.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Use a function pointer to decide whether to call i2c_add_adapter or
i2c_add_numbered_adapter. This makes the code more compact than the
current strategy of having the common code in a separate function.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Add an i2c mux driver providing access to i2c bus segments using a
hardware MUX sitting on a master bus and controlled through gpio pins.
E.G. something like:
---------- ---------- Bus segment 1 - - - - -
| | SCL/SDA | |-------------- | |
| |------------| |
| | | | Bus segment 2 | |
| Linux | GPIO 1..N | MUX |--------------- Devices
| |------------| | | |
| | | | Bus segment M
| | | |---------------| |
---------- ---------- - - - - -
SCL/SDA of the master I2C bus is multiplexed to bus segment 1..M
according to the settings of the GPIO pins 1..N.
Signed-off-by: Peter Korsgaard <peter.korsgaard@barco.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Ben Dooks
Richard woodruff
Balaji T K
Kevin Hilman
Wolfram Sang
Mark Brown
Jean Delvare
Andres Salomon
Linus Torvalds
Michael Hennerich
Peter Korsgaard
Joe Perches