SMBus Host Notify allows a slave device to act as a master on a bus to
notify the host of an interrupt. On Intel chipsets, the functionality
is directly implemented in the firmware. We just need to export a
function to call .alert() on the proper device driver.
i2c_handle_smbus_host_notify() behaves like i2c_handle_smbus_alert().
When called, it schedules a task that will be able to sleep to go through
the list of devices attached to the adapter.
The current implementation allows one Host Notification to be scheduled
while an other is running.
Tested-by: Andrew Duggan <aduggan@synaptics.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The root i2c adapter lock is then no longer held by the i2c mux during
accesses behind the i2c gate, and such accesses need to take that lock
just like any other ordinary i2c accesses do.
So, declare the i2c gate mux-locked, and zap the regmap overrides
that makes the i2c accesses unlocked and use plain old regmap
accesses. This also removes the need for the regmap wrappers used by
rtl2832_sdr, so deconvolute the code further and provide the regmap
handle directly instead of the wrapper functions.
Tested-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The root i2c adapter lock is then no longer held by the i2c mux during
accesses behind the i2c gate, and such accesses need to take that lock
just like any other ordinary i2c accesses do.
So, declare the i2c gate mux-locked, and zap the code that makes the
i2c accesses unlocked. But add a mutex so that firmware commands are
still serialized.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The root i2c adapter lock is then no longer held by the i2c mux during
accesses behind the i2c gate, and such accesses need to take that lock
just like any other ordinary i2c accesses do.
So, declare the i2c gate mux-locked, and zap the code that makes the
unlocked i2c accesses and just use ordinary regmap_write accesses.
This also happens to fix the deadlock described in
http://patchwork.ozlabs.org/patch/584776/ authored by
Adriana Reus <adriana.reus@intel.com> and submitted by
Daniel Baluta <daniel.baluta@intel.com>
----------8<----------
iio: imu: inv_mpu6050: Fix deadlock between i2c adapter lock and mpu lock
This deadlock occurs if the accel/gyro and the sensor on the auxiliary
I2C (in my setup it's an ak8975) are working at the same time.
Scenario:
T1 T2
==== ====
inv_mpu6050_read_fifo aux sensor op (eg. ak8975_read_raw)
| |
mutex_lock(&indio_dev->mlock) i2c_transfer
| |
i2c transaction i2c adapter lock
| |
i2c adapter lock i2c_mux_master_xfer
|
inv_mpu6050_select_bypass
|
mutex_lock(&indio_dev->mlock)
When we operate on an mpu sensor the order of locking is mpu lock
followed by the i2c adapter lock. However, when we operate the auxiliary
sensor the order of locking is the other way around.
...
----------8<----------
The reason this patch fixes the deadlock is that T2 does not grab the
i2c adapter lock until the very end (and grabs the newfangled i2c mux
lock where it previously grabbed the i2c adapter lock).
Acked-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Daniel Baluta <daniel.baluta@intel.com>
Tested-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This path fix spelling typos found in Documentation/i2c.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
We now have seperate address spaces for 10 bit and we-are-slave clients.
Update the sysfs device instantiation method to support these types by
accepting the address offsets that are assigned to the extra address
spaces. Update the documentation, too.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c updates from Wolfram Sang:
"Highlights:
- new drivers for Mediatek I2C, APM X-Gene, Broadcom Settop
- major updates to at91, davinci
- bugfixes to the mux infrastructure when dealing with the new quirk
mechanism
- more users for the bus recovery feature
- further improvements to the slave framework
Plus the usual bunch of smaller driver and core improvements and
fixes.
There is one patch removing old code from an ARM platform. This has
been acked by the sh_mobile maintainer Simon Horman"
* 'i2c/for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (48 commits)
i2c: busses: i2c-bcm2835: limits cdiv to allowed values
i2c: sh_mobile: use proper type for timeout
i2c: sh_mobile: use adapter default for timeout
i2c: rcar: use proper type for timeout
i2c: rcar: use adapter default for timeout
i2c: designware: Make sure the device is suspended before disabling runtime PM
i2c: tegra: apply size limit quirk
i2c: tegra: don't advertise SMBUS_QUICK
i2c: octeon: remove unused signal handling
i2c: davinci: Optimize SCL generation
i2c: mux: pca954x: Use __i2c_transfer because of quirks
i2c: mux: Use __i2c_transfer() instead of calling parent's master_xfer()
i2c: use parent adapter quirks in mux
i2c: bcm2835: clear reserved bits in S-Register
ARM: shmobile: r8a7740: remove I2C errata handling
i2c: sh_mobile: add errata workaround
i2c: at91: fix code checker warnings
i2c: busses: xgene-slimpro: fix incorrect __init declation for probe
i2c: davinci: Avoid sending to own address
i2c: davinci: Refactor i2c_davinci_wait_bus_not_busy()
...
There was some confusion what was needed to utilize the slave support,
so let's be more precise about this. Add an introductory paragraph to
the development section while we are here.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Since commit 607ca46e97 ('UAPI: (Scripted) Disintegrate include/linux') the
list of functionality constants moved to include/uapi/linux/i2c.h. Update the
reference accordingly.
Fixes: 607ca46e97 ('UAPI: (Scripted) Disintegrate include/linux')
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
New drivers should use PM ops instead of the legacy suspend/resume
callbacks. Update the I2C device driver guides to reflect this.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch adds the I2C/SMBus Device IDs for the Intel Sunrise Point PCH.
Signed-off-by: James Ralston <james.d.ralston@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The example code provided with the i2c device interface documentation
won't compile since it uses the reserved word "register" to name a
variable.
The compiler fails with this error message:
error: expected identifier or '(' before '=' token
__u8 register = 0x20; /* Device register to access */
^
Rename the variable "register" to simply "reg" in the example code.
Another couple of typos has been fixed as well.
[Change "! =" to "!=".]
Signed-off-by: Jose Alarcon Roldan <jose.alarcon.roldan@gmail.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some chips implement banked register ranges. This allows implementing
more registers than the limited 8-bit address space originally allows.
In order to access a register on these chips, you must first select
the proper bank. Add support for this mechanism to the i2c-stub driver
so that such chips can be emulated. All the bank settings are passed
as module parameters.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
SMBus block commands are different to I2C block commands since
the returned data is not normally accessible with byte or word
commands on other command offsets. Add linked list of 'block'
commands to support those commands.
Access mechanism is quite simple: Block commands must be written
before they can be read. Subsequent writes can be partial. Block
read commands always return the number of bytes associated with
the longest previous write.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Sort the entries alphabetically. Make the introductory paragraph more
precise. Skip useless 'Flag' introduction from the entries. Remove
trailing white spaces from the file. Add missing I2C_M_STOP entry.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Wolfram Sang
Benjamin Tissoires
Peter Rosin
Antti Palosaari
Masanari Iida
Alexandra Yates
Jarkko Nikula
Wolfram Sang
Ondrej Zary
Linus Torvalds
Baruch Siach
Lars-Peter Clausen
Devin Ryles
james.d.ralston@intel.com
Jose Manuel Alarcon Roldan
Jean Delvare
Guenter Roeck