Commit graph

303 commits

Author SHA1 Message Date
Wolfram Sang
76cc9f0efd i2c: headers: reformat header comment and update copyright
Let's stick to coding style.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-06-14 23:24:33 +02:00
Wolfram Sang
2caea56f56 i2c: headers: update docs about I2C_CLIENT_*
Update kerneldoc for i2c client flags because they increased over time.
Also, move them to a position where they can be more easily found.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-06-14 23:24:33 +02:00
Wolfram Sang
d68222d4d6 i2c: headers: always have a named variable in arguments
Much better to read and understand. Naming for i2c_adapter is not
consistent (yet), so use the name which is also used in core code.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-06-14 23:24:33 +02:00
Wolfram Sang
e1714daad7 i2c: headers: don't use 'dev' as adapter variable
It is not a struct device, so 'dev' is confusing. Use 'adap', the most
common name.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-06-14 23:24:33 +02:00
Ruslan Babayev
5213d7efc8 i2c: acpi: export i2c_acpi_find_adapter_by_handle
This allows drivers to lookup i2c adapters on ACPI based systems similar to
of_get_i2c_adapter_by_node() with DT based systems.

Signed-off-by: Ruslan Babayev <ruslan@babayev.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-06-02 21:56:04 +02:00
Thomas Gleixner
1621633323 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 1
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  51 franklin street fifth floor boston ma 02110 1301 usa

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option [no]_[pad]_[ctrl] any later version this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to the free
  software foundation inc 51 franklin street fifth floor boston ma
  02110 1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 176 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190519154040.652910950@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 11:28:39 +02:00
Heiner Kallweit
b8f5fe3bc5 i2c: core: add device-managed version of i2c_new_dummy
i2c_new_dummy is typically called from the probe function of the
driver for the primary i2c client. It requires calls to
i2c_unregister_device in the error path of the probe function and
in the remove function.
This can be simplified by introducing a device-managed version.

Note the changed error case return value type: i2c_new_dummy returns
NULL whilst devm_i2c_new_dummy_device returns an ERR_PTR.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
[wsa: rename new functions and fix minor kdoc issues]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-05-17 19:29:40 +02:00
Wolfram Sang
4db61c2a16 i2c: core: ratelimit 'transfer when suspended' errors
There are two problems with WARN_ON() here. One: It is not ratelimited.
Two: We don't see which adapter was used when trying to transfer
something when already suspended. Implement a custom ratelimit once per
adapter and use dev_WARN there. This fixes both issues. Drawback is that
we don't see if multiple drivers are trying to transfer with the same
adapter while suspended. They need to be discovered one after the other
now. This is better than a high CPU load because a really broken driver
might try to resend endlessly.

Fixes: 9ac6cb5fbb ("i2c: add suspended flag and accessors for i2c adapters")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org # v5.1+
2019-05-03 15:25:00 +02:00
Wolfram Sang
63b96983a5 i2c: core: introduce callbacks for atomic transfers
We had the request to access devices very late when interrupts are not
available anymore multiple times now. Mostly to prepare shutdown or
reboot. Allow adapters to specify a specific callback for this case.
Note that we fall back to the generic {master|smbus}_xfer callback if
this new atomic one is not present. This is intentional to preserve the
previous behaviour and avoid regressions. Because there are drivers not
using interrupts or because it might have worked "accidently" before.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Stefan Lengfeld <contact@stefanchrist.eu>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-04-16 13:08:11 +02:00
Wolfram Sang
f6ac28d616 i2c: apply coding style for struct i2c_adapter
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-03-27 14:14:50 +01:00
Jim Broadus
93b6604c5a i2c: Allow recovery of the initial IRQ by an I2C client device.
A previous change allowed I2C client devices to discover new IRQs upon
reprobe by clearing the IRQ in i2c_device_remove. However, if an IRQ was
assigned in i2c_new_device, that information is lost.

For example, the touchscreen and trackpad devices on a Dell Inspiron laptop
are I2C devices whose IRQs are defined by ACPI extended IRQ types. The
client device structures are initialized during an ACPI walk. After
removing the i2c_hid device, modprobe fails.

This change caches the initial IRQ value in i2c_new_device and then resets
the client device IRQ to the initial value in i2c_device_remove.

Fixes: 6f108dd70d ("i2c: Clear client->irq in i2c_device_remove")
Signed-off-by: Jim Broadus <jbroadus@gmail.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
[wsa: this is an easy to backport fix for the regression. We will
refactor the code to handle irq assignments better in general.]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-02-24 14:43:22 +01:00
Andy Shevchenko
b33a02aadc i2c: acpi: Move I2C bits from acpi.h to i2c.h
As discussed previously the best location for certain bus related bits,
e.g. I2C, is its own realm of the headers.

In order to uncontaminate acpi.h move the I2C bits to i2c.h.

There is no functional change intended.

Link: https://lkml.org/lkml/2018/11/28/744
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-01-15 23:20:02 +01:00
Wolfram Sang
9ac6cb5fbb i2c: add suspended flag and accessors for i2c adapters
A few drivers open code the handling of suspended adapters. It could be
handled by the core, though, to ensure generic handling. This patch adds
the flag and accessor functions. The usage of these helpers is optional,
though. See the kerneldoc in this patch. Using the new flag, we now
reject further transfers if the adapter is already marked suspended.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-01-08 21:01:07 +01:00
Wolfram Sang
82fe39a6bc i2c: refactor function to release a DMA safe buffer
a) rename to 'put' instead of 'release' to match 'get' when obtaining
   the buffer
b) change the argument order to have the buffer as first argument
c) add a new argument telling the function if the message was
   transferred. This allows the function to be used also in cases
   where setting up DMA failed, so the buffer needs to be freed without
   syncing to the message buffer.

Also convert the only user.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-08-30 23:13:15 +02:00
Wolfram Sang
0c36dd37d5 i2c: remove deprecated attach_adapter callback
There aren't any users left. Remove this callback from the 2.4 times.
Phew, finally, that took years to reach...

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-08-24 14:42:45 +02:00
Andy Shevchenko
4717be73c2 i2c: core: Parse SDA hold time from firmware
There are two drivers already using the SDA hold time setting.
It might be more in the future, thus, make I2C core to parse the setting
for us if provided by firmware.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-08-08 22:28:52 +02:00
Wolfram Sang
d9cfe2ce24 i2c: quirks: add zero length checks
Some adapters do not support a message length of 0. Add this as a quirk
so drivers don't have to open code it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-08-04 23:24:03 +02:00
Wolfram Sang
7ca5f6be79 i2c: recovery: add get_bus_free callback
Some IP cores have an internal 'bus free' logic which may be more
advanced than just checking if SDA is high. Add a separate callback to
get this status. Filling it is optional.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-17 10:46:51 +02:00
Wolfram Sang
ffc59c496b i2c: recovery: require either get_sda or set_sda
For bus recovery, we either need to bail out early if we can read SDA or
we need to send STOP after every pulse. Otherwise recovery might be
misinterpreted as an unwanted write. So, require one of those SDA
handling functions to avoid this problem.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-17 10:41:55 +02:00
Wolfram Sang
fb2896a779 Merge branch 'i2c/precise-locking-names_immutable' into i2c/for-4.19 2018-07-13 00:12:53 +02:00
Peter Rosin
3f3a89e1d7 i2c: remove i2c_lock_adapter and use i2c_lock_bus directly
The i2c_lock_adapter name is ambiguous since it is unclear if it
refers to the root adapter or the adapter you name in the argument.
The natural interpretation is the adapter you name in the argument,
but there are historical reasons for that not being the case; it
in fact locks the root adapter. Just remove the function and force
users to spell out the I2C_LOCK_ROOT_ADAPTER name to indicate what
is really going on. Also remove i2c_unlock_adapter, of course.

This patch was generated with

git grep -l 'i2c_\(un\)\?lock_adapter' \
| xargs sed -i 's/i2c_\(un\)\?lock_adapter(\([^)]*\))/'\
'i2c_\1lock_bus(\2, I2C_LOCK_ROOT_ADAPTER)/g'

followed by white-space touch-up.

Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Tested-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-13 00:09:37 +02:00
Peter Rosin
63453b59e4 i2c: smbus: add unlocked __i2c_smbus_xfer variant
Removes all locking from i2c_smbus_xfer and renames it to __i2c_smbus_xfer,
then adds a new i2c_smbus_xfer function that simply grabs the lock while
calling the unlocked variant.

This is not perfectly equivalent, since i2c_smbus_xfer was callable from
atomic/irq context if you happened to end up emulating SMBus with an I2C
transfer, and that is no longer the case with this patch. It is unknown
(to me) if anything depends on that quirk, but it seems fragile enough to
simply break those cases and require them to call i2c_transfer directly
instead.

While at it, for consistency rename the 2nd to last argument (size) of
the i2c_smbus_xfer declaration to protocol and remove the surplus extern
marker.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-03 22:57:25 +02:00
Boris Brezillon
da0086d018 i2c: Export of_i2c_get_board_info()
I3C busses have to know about all I2C devices connected on the I3C bus
to properly initialize the I3C master, and I2C frames can't be sent on
the bus until this initialization is done.

We can't let the I2C core parse the DT and instantiate I2C devices as
part of its i2c_add_adapter() procedure because, when done this way,
I2C devices are directly registered to the device-model and might be
attached to drivers which could in turn start sending frames on the bus,
which won't work since, as said above, the bus is not yet initialized.

Export of_i2c_register_device() in order to let the I3C core parse the
I2C device nodes by itself and initialize the bus.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-22 13:42:16 +02:00
Boris Brezillon
4fad8868af i2c: Get rid of i2c_board_info->archdata
The only user of i2c_board_info->archdata is the OF parsing code and it
just pass a zero-initialized object which has the same effect as leaving
->archdata to NULL since the client object is allocated with kzalloc().

Get rid of this useless field.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-15 10:42:20 +02:00
Peter Rosin
dde67eb1be i2c: add i2c_get_device_id() to get the standard i2c device id
Can be used during probe to double check that the probed device is
what is expected.

Loosely based on code from Adrian Fiergolski <adrian.fiergolski@cern.ch>.

Tested-by: Adrian Fiergolski <adrian.fiergolski@cern.ch>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Peter Rosin <peda@axentia.se>
2018-03-06 10:57:59 +01:00
Wolfram Sang
8092178ffe i2c: add 'set_sda' to bus_recovery_info
This will be needed when we want to create STOP conditions, too, later.
Create the needed fields and populate them for the GPIO case if the GPIO
is set to output.

Tested-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-01-16 00:04:19 +01:00
Wolfram Sang
6c92204e44 i2c: add identifier in declarations for i2c_bus_recovery
No reason to have them undefined, so let's add them.

Tested-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-01-16 00:04:03 +01:00
Wolfram Sang
766a4f27f3 i2c: make kerneldoc about bus recovery more precise
"Used internally" is vague. What it actually means is that those fields
are populated by the core if valid GPIOs are provided. Change the
comments to reflect that.

Tested-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-01-16 00:04:02 +01:00
Wolfram Sang
ba98645c7d i2c: add i2c_master_{send|recv}_dmasafe
Use the new helper to create variants of i2c_master_{send|recv} which
mark their buffers as DMA safe.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-12-03 21:23:38 +01:00
Wolfram Sang
8a91732b3b i2c: refactor i2c_master_{send_recv}
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>
2017-12-03 21:22:29 +01:00
Wolfram Sang
e94bc5d18b i2c: add helpers to ease DMA handling
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>
2017-12-03 20:47:44 +01:00
Phil Reid
e1eb7d28c0 i2c: remove legacy integer scl/sda gpio for recovery
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>
2017-11-27 18:40:01 +01:00
Phil Reid
3991c5c80b i2c: Switch to using gpiod interface for gpio bus recovery
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>
2017-11-27 18:39:13 +01:00
Stefan Lengfeld
901a891fa6 i2c: use macro IS_ENABLED in header i2c.h
Using the macro IS_ENABLED to check the option CONFIG_I2C=(y|m) makes
the code nicer.  No functional change.

Signed-off-by: Stefan Lengfeld <contact@stefanchrist.eu>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-11-27 18:31:57 +01:00
Hans de Goede
728fe6cef2 i2c: Allow overriding dev_name through board_info
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>
2017-10-27 15:51:51 +02:00
Wolfram Sang
9c80034921 i2c: rephrase explanation of I2C_CLASS_DEPRECATED
Hopefully making clear that it is not needed for new drivers.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-07-31 17:33:53 +02:00
Andy Shevchenko
8f1a357d41 i2c: Provide a stub for i2c_detect_slave_mode()
Drivers would like to call i2c_detect_slave_mode() even if !I2C_SLAVE.
Give them what they want to,

Otherwise kernel will not compile:
drivers/i2c/busses/i2c-designware-platdrv.c: In function ‘dw_i2c_plat_probe’:
drivers/i2c/busses/i2c-designware-platdrv.c:331:6: error: implicit declaration of function ‘i2c_detect_slave_mode’ [-Werror=implicit-function-declaration]
  if (i2c_detect_slave_mode(&pdev->dev))
      ^~~~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors

Fixes: 6e38cf3b44 ("i2c: designware: Let slave adapter support be optional")
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-07-08 21:51:43 +02:00
Linus Torvalds
16a12fa9ae Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input subsystem updates from Dmitry Torokhov:

 - a big update from Mauro converting input documentation to ReST format

 - Synaptics PS/2 is now aware of SMBus companion devices, which means
   that we can now use native RMI4 protocol to handle touchpads, instead
   of relying on legacy PS/2 mode.

 - we removed support from BMA180 accelerometer from input devices as it
   is now handled properly by IIO

 - update to TSC2007 to corretcly report pressure

 - other miscellaneous driver fixes.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (152 commits)
  Input: ar1021_i2c - use BIT to check for a bit
  Input: twl4030-pwrbutton - use input_set_capability() helper
  Input: twl4030-pwrbutton - use correct device for irq request
  Input: ar1021_i2c - enable touch mode during open
  Input: add uinput documentation
  dt-bindings: input: add bindings document for ar1021_i2c driver
  dt-bindings: input: rotary-encoder: fix typo
  Input: xen-kbdfront - add module parameter for setting resolution
  ARM: pxa/raumfeld: fix compile error in rotary controller resources
  Input: xpad - do not suggest writing to Dominic
  Input: xpad - don't use literal blocks inside footnotes
  Input: xpad - note that usb/devices is now at /sys/kernel/debug/
  Input: docs - freshen up introduction
  Input: docs - split input docs into kernel- and user-facing
  Input: docs - note that MT-A protocol is obsolete
  Input: docs - update joystick documentation a bit
  Input: docs - remove disclaimer/GPL notice
  Input: fix "Game console" heading level in joystick documentation
  Input: rotary-encoder - remove references to platform data from docs
  Input: move documentation for Amiga CD32
  ...
2017-05-03 12:38:20 -07:00
Hans de Goede
d1d84bb953 i2c: core: Allow drivers to disable i2c-core irq mapping
By default the i2c-core will try to get an irq with index 0 on ACPI / of
instantiated devices. This is troublesome on some ACPI systems where the
irq info at index 0 in the CRS table may contain nonsense and/or point
to an irqchip for which there is no Linux driver.

If this happens then before this commit the driver's probe method would
never get called because i2c_device_probe will try to get an irq by
calling acpi_dev_gpio_irq_get which will always return -EPROBE in this
case, as it waits for a matching irqchip driver to load. Thus causing
the driver to not get a chance to bind.

This commit adds a new disable_i2c_core_irq_mapping flag to struct
i2c_driver which a driver can set to tell the core to skip irq mapping.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-04-16 22:02:25 +02:00
Hans de Goede
605f8fc224 i2c: core: Add new i2c_acpi_new_device helper function
By default the i2c subsys creates an i2c-client for the first I2cSerialBus
resource of an acpi_device, but some acpi_devices have multiple
I2cSerialBus resources and we may want to instantiate i2c-clients for
the others.

This commit adds a new i2c_acpi_new_device function which can be used to
create an i2c-client for any I2cSerialBus resource of an acpi_device.

Note that the other resources may even be on a different i2c bus, so just
retrieving the client address is not enough.

Here is an example DSDT excerpt from such a device:

Device (WIDR)
{
    Name (_HID, "INT33FE" /* XPOWER Battery Device */)
    Name (_CID, "INT33FE" /* XPOWER Battery Device */)
    Name (_DDN, "WC PMIC Battery Device")
<snip>
    Name (RBUF, ResourceTemplate ()
    {
        I2cSerialBusV2 (0x005E, ControllerInitiated, 0x000186A0,
            AddressingMode7Bit, "\\_SB.PCI0.I2C7",
            0x00, ResourceConsumer, , Exclusive,
            )
        I2cSerialBusV2 (0x0036, ControllerInitiated, 0x000186A0,
            AddressingMode7Bit, "\\_SB.PCI0.I2C1",
            0x00, ResourceConsumer, , Exclusive,
            )
        I2cSerialBusV2 (0x0022, ControllerInitiated, 0x00061A80,
            AddressingMode7Bit, "\\_SB.PCI0.I2C1",
            0x00, ResourceConsumer, , Exclusive,
            )
        I2cSerialBusV2 (0x0054, ControllerInitiated, 0x00061A80,
            AddressingMode7Bit, "\\_SB.PCI0.I2C1",
            0x00, ResourceConsumer, , Exclusive,
            )
        GpioInt (Level, ActiveLow, Exclusive, PullNone, 0x0000,
            "\\_SB.PCI0.I2C7.PMI5", 0x00, ResourceConsumer, ,
            )
            {   // Pin list
        0x0012
            }
        GpioInt (Edge, ActiveLow, ExclusiveAndWake, PullNone, 0x0000,
            "\\_SB.GPO1", 0x00, ResourceConsumer, ,
            )
            {   // Pin list
        0x0005
            }
        GpioInt (Level, ActiveLow, Exclusive, PullNone, 0x0000,
            "\\_SB.PCI0.I2C7.PMI5", 0x00, ResourceConsumer, ,
            )
            {   // Pin list
        0x0013
            }
    })
    Method (_CRS, 0, NotSerialized)  // _CRS: Current Resource Settings
    {
        Return (RBUF) /* \_SB_.PCI0.I2C7.WIDR.RBUF */
    }
<snip>
}

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-04-16 22:02:02 +02:00
Dmitry Torokhov
4124c4eba4 i2c: allow attaching IRQ resources to i2c_board_info
Simple integer for interrupt number is not expressive enough, as it does
not convey interrupt trigger type that should be used. Let's allow
attaching array of resources to the board info and have i2c core parse
first IRQ resource and set up interrupt trigger as needed.

Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2017-04-01 09:36:19 -07:00
Dmitry Torokhov
00a06c22e9 i2c: export i2c_client_type structure
i2c bus has 2 different types of device belonging to the same bus and
bus notifiers use device type to distinguish between adapters and clients.
Previously we only had i2c_adapter_type exported, which made code wanting
to work with i2c_client devices test for type not equal to adapter type.
This unfortunately is not safe if we ever add another type to the bus,
so let's export i2c_client_type as well.

Reviewed-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2017-04-01 09:35:08 -07:00
Ingo Molnar
037741a6d4 sched/headers: Prepare for the removal of <linux/rtmutex.h> from <linux/sched.h>
Fix up missing #includes in other places that rely on sched.h doing that for them.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:32 +01:00
Linus Torvalds
7067739df2 Merge branch 'i2c/for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 "I2C has for you two new drivers (Tegra BPMP and STM32F4), interrupt
  support for pca954x muxes, and a bunch of driver bugfixes and
  improvements. Nothing really special this cycle.

  A few commits have been added to my tree just recently. Those are the
  Tegra BPMP driver and a few straightforward bugfixes or cleanups which
  I prefer to have upstream rather soonish. The rest had proper
  linux-next exposure"

* 'i2c/for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (25 commits)
  i2c: thunderx: Replace pci_enable_msix()
  i2c: exynos5: fix arbitration lost handling
  i2c: exynos5: disable fifo-almost-empty irq signal when necessary
  i2c: at91: ensure state is restored after suspending
  i2c: bcm2835: Avoid possible NULL ptr dereference
  i2c: Add Tegra BPMP I2C proxy driver
  dt-bindings: Add Tegra186 BPMP I2C binding
  misc: eeprom: at24: use device_property_*() functions instead of of_get_property()
  i2c: mux: pca954x: Add interrupt controller support
  dt: bindings: i2c-mux-pca954x: Add documentation for interrupt controller
  i2c: mux: pca954x: Add missing pca9542 definition to chip_desc
  i2c: riic: correctly finish transfers
  i2c: i801: Add support for Intel Gemini Lake
  i2c: mux: pca9541: Export OF device ID table as module aliases
  i2c: mux: pca954x: Export OF device ID table as module aliases
  i2c: mux: mlxcpld: remove unused including <linux/version.h>
  i2c: busses: constify i2c_algorithm structures
  i2c: i2c-mux-gpio: rename i2c-gpio-mux to i2c-mux-gpio
  i2c: sh_mobile: document support for r8a7796 (R-Car M3-W)
  i2c: i2c-cros-ec-tunnel: Reduce logging noise
  ...
2017-02-25 14:21:18 -08:00
Dmitry Torokhov
d3e1b617ae i2c: allow specify device properties in i2c_board_info
With many drivers converting to using generic device properties, it is
useful to provide array of device properties when instantiating new i2c
client via i2c_board_info and have them automatically added to the device
in question.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-02-08 13:34:41 +01:00
Luis Oliveira
cefae80249 i2c: core: helper function to detect slave mode
This function has the purpose of mode detection by checking the
device nodes for a reg matching with the I2C_OWN_SLAVE_ADDREESS flag.
Currently only checks using OF functions (ACPI slave not supported yet).

Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-01-28 22:12:37 +01:00
Dmitry Torokhov
331c342552 i2c: do not enable fall back to Host Notify by default
Falling back unconditionally to HostNotify as primary client's interrupt
breaks some drivers which alter their functionality depending on whether
interrupt is present or not, so let's introduce a board flag telling I2C
core explicitly if we want wired interrupt or HostNotify-based one:
I2C_CLIENT_HOST_NOTIFY.

For DT-based systems we introduce "host-notify" property that we convert
to I2C_CLIENT_HOST_NOTIFY board flag.

Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-01-12 20:06:15 +01:00
Benjamin Tissoires
4d5538f588 i2c: use an IRQ to report Host Notify events, not alert
The current SMBus Host Notify implementation relies on .alert() to
relay its notifications. However, the use cases where SMBus Host
Notify is needed currently is to signal data ready on touchpads.

This is closer to an IRQ than a custom API through .alert().
Given that the 2 touchpad manufacturers (Synaptics and Elan) that
use SMBus Host Notify don't put any data in the SMBus payload, the
concept actually matches one to one.

Benefits are multiple:
- simpler code and API: the client will just have an IRQ, and
  nothing needs to be added in the adapter beside internally
  enabling it.
- no more specific workqueue, the threading is handled by IRQ core
  directly (when required)
- no more races when removing the device (the drivers are already
  required to disable irq on remove)
- simpler handling for drivers: use plain regular IRQs
- no more dependency on i2c-smbus for i2c-i801 (and any other adapter)
- the IRQ domain is created automatically when the adapter exports
  the Host Notify capability
- the IRQ are assign only if ACPI, OF and the caller did not assign
  one already
- the domain is automatically destroyed on remove
- fewer lines of code (minus 20, yeah!)

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-11-24 16:22:06 +01:00
Lee Jones
b8a1a4cd5a i2c: Provide a temporary .probe_new() call-back type
This will aid the seamless removal of the current probe()'s, more
commonly unused than used second parameter.  Most I2C drivers can
simply switch over to the new interface, others which have DT
support can use its own matching instead and others can call
i2c_match_id() themselves.  This brings I2C's device probe method
into line with other similar interfaces in the kernel and prevents
the requirement to pass an i2c_device_id table.

Suggested-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
[Kieran: fix rebase conflicts and adapt for dev_pm_domain_{attach,detach}]
Tested-by: Kieran Bingham <kieran@bingham.xyz>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-11-17 16:10:23 +01:00
Lee Jones
5f441fcaa3 i2c: Export i2c_match_id() for direct use by device drivers
When there was no other way to match a I2C device to driver i2c_match_id()
was exclusively used.  However, now there are other types of tables which
are commonly supplied, matching on an i2c_device_id table is used less
frequently.  Instead of _always_ calling i2c_match_id() from within the
framework, we only need to do so from drivers which have no other way of
matching.  This patch makes i2c_match_id() available to the aforementioned
device drivers.

Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Tested-by: Kieran Bingham <kieran@bingham.xyz>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-11-17 16:10:22 +01:00
Lee Jones
298d4de1ed i2c: Match using traditional OF methods, then by vendor-less compatible strings
This function provides a single call for all I2C devices which need to
match firstly using traditional OF means i.e by of_node, then if that
fails we attempt to match using the supplied I2C client name with a
list of supplied compatible strings with the '<vendor>,' string
removed.  The latter is required due to the unruly naming conventions
used currently by I2C devices.

Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
[Kieran: Fix static inline usage on !CONFIG_OF]
Tested-by: Kieran Bingham <kieran@bingham.xyz>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-11-17 16:10:20 +01:00
Bartosz Golaszewski
8dd1fe1594 i2c: export i2c_adapter_depth()
For crazy setups in which an i2c gpio expander is behind an i2c gpio
multiplexer controlled by a gpio provided a second expander using the
same device driver we need to explicitly tell lockdep how to handle
nested locking.

Export i2c_adapter_depth() as public API to be reused outside of i2c
core code.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Peter Rosin <peda@axentia.se>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-09-24 10:48:18 +02:00
Peter Rosin
d1ed7985b9 i2c: move locking operations to their own struct
This makes it trivial to constify them, so do that.

Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-30 22:56:14 +02:00
Jarkko Nikula
5853b22d96 i2c: core: Add function for finding the bus speed from ACPI, take 2
ACPI 5 specification doesn't have property for the I2C bus speed but
I2cSerialBus resource descriptor which define each controller-slave
connection define the maximum speed supported by that connection.

Thus finding the maximum safe speed for the bus is to walk through all
I2cSerialBus resources that are associated to I2C controller and use the
speed of slowest connection.

Add function i2c_acpi_find_bus_speed() to the i2c-core that adapter
drivers can call prior registering itself to core.

This implies two-step walk through the I2cSerialBus resources: call to
i2c_acpi_find_bus_speed() does the first scan and finds the safe bus
speed that adapter drivers can set up. Adapter driver registration does
the second scan when i2c-core creates the I2C slaves by calling the
i2c_acpi_register_devices(). In that way the bus speed is set in case
slave device probe gets called during registration and does communication.

Previous version commit 55d38d060e ("i2c: core: Add function for finding
the bus speed from ACPI") got reverted due merge conflicts from
commit 525e6fabea ("i2c / ACPI: add support for ACPI reconfigure
notifications").

This version is a bit bigger than previous version but is still sharing
the lowest and complicated part of I2cSerialBus lookup routines with the
existing code.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-26 00:42:10 +02:00
Peter Rosin
fb79e09a74 i2c: add i2c_trylock_bus wrapper, use it
This unifies usage with i2c_lock_bus and i2c_unlock_bus, and paves the
way for the next patch which looks a bit saner with this preparatory
work taken care of beforehand.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-25 18:02:14 +02:00
Wolfram Sang
38d0fc4662 Revert "i2c: core: Add function for finding the bus speed from ACPI"
This reverts commit 55d38d060e. There were
too heavy merge conflicts and the driver code making use of this was not
ready yet anyhow. So, we wait one cycle.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-07-19 05:57:23 +02:00
Jarkko Nikula
55d38d060e i2c: core: Add function for finding the bus speed from ACPI
ACPI 5 specification doesn't have property for the I2C bus speed but
I2cSerialBus resource descriptors which define each controller-slave
connection define the maximum speed supported by that connection.

Thus finding the maximum safe speed for the bus is to walk all
I2cSerialBus resources that are associated to I2C controller and use
the speed of slowest connection.

Add function i2c_acpi_find_bus_speed() to the i2c-core that adapter
drivers can call prior registering itself to core.

This implies two-step walk through the I2cSerialBus resources: call to
i2c_acpi_find_bus_speed() does the first scan and finds the safe bus
speed that adapter drivers can set up. Adapter driver registration does
the second scan when i2c-core creates the I2C slaves by calling the
i2c_acpi_register_devices(). In that way the bus speed is set in case
slave device probe gets called during registration and does
communication.

Implement this by reusing the existing ACPI I2C walk routines in the
i2c-core. Extend them so that slowest connection speed is saved during
the walk and I2C slaves are registered only when calling through the
i2c_acpi_register_devices() with the i2c_adapter pointer.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-07-14 22:25:10 +09:00
Benjamin Tissoires
e456cd37bc i2c: smbus: add SMBus Host Notify support
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>
2016-06-17 13:24:05 +02:00
Benjamin Tissoires
b4f210541f i2c: add a protocol parameter to the alert callback
.alert() is meant to be generic, but there is currently no way
for the device driver to know which protocol generated the alert.
Add a parameter in .alert() to help the device driver to understand
what is given in data.

This patch is required to have the support of SMBus Host Notify protocol
through .alert().

Tested-by: Andrew Duggan <aduggan@synaptics.com>
For hwmon:
Acked-by: Guenter Roeck <linux@roeck-us.net>
For IPMI:
Acked-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-06-17 12:41:25 +02:00
Jean-Michel Hautbois
0f614d834b i2c: Add generic support passing secondary devices addresses
Some I2C devices have multiple addresses assigned, for example each address
corresponding to a different internal register map page of the device.
So far drivers which need support for this have handled this with a driver
specific and non-generic implementation, e.g. passing the additional address
via platform data.

This patch provides a new helper function called i2c_new_secondary_device()
which is intended to provide a generic way to get the secondary address
as well as instantiate a struct i2c_client for the secondary address.

The function expects a pointer to the primary i2c_client, a name
for the secondary address and an optional default address. The name is used
as a handle to specify which secondary address to get.

The default address is used as a fallback in case no secondary address
was explicitly specified. In case no secondary address and no default
address were specified the function returns NULL.

For now the function only supports look-up of the secondary address
from devicetree, but it can be extended in the future
to for example support board files and/or ACPI.

Signed-off-by: Jean-Michel Hautbois <jean-michel.hautbois@veo-labs.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-06-13 22:32:09 +02:00
Peter Rosin
6ef91fcca8 i2c: mux: relax locking of the top i2c adapter during mux-locked muxing
With a i2c topology like the following

                       GPIO ---|  ------ BAT1
                        |      v /
   I2C  -----+----------+---- MUX
             |                   \
           EEPROM                 ------ BAT2

there is a locking problem with the GPIO controller since it is a client
on the same i2c bus that it muxes. Transfers to the mux clients (e.g. BAT1)
will lock the whole i2c bus prior to attempting to switch the mux to the
correct i2c segment. In the above case, the GPIO device is an I/O expander
with an i2c interface, and since the GPIO subsystem knows nothing (and
rightfully so) about the lockless needs of the i2c mux code, this results
in a deadlock when the GPIO driver issues i2c transfers to modify the
mux.

So, observing that while it is needed to have the i2c bus locked during the
actual MUX update in order to avoid random garbage on the slave side, it
is not strictly a must to have it locked over the whole sequence of a full
select-transfer-deselect mux client operation. The mux itself needs to be
locked, so transfers to clients behind the mux are serialized, and the mux
needs to be stable during all i2c traffic (otherwise individual mux slave
segments might see garbage, or worse).

Introduce this new locking concept as "mux-locked" muxes, and call the
pre-existing mux locking scheme "parent-locked".

Modify the i2c mux locking so that muxes that are "mux-locked" locks only
the muxes on the parent adapter instead of the whole i2c bus when there is
a transfer to the slave side of the mux. This lock serializes transfers to
the slave side of the muxes on the parent adapter.

Add code to i2c-mux-gpio and i2c-mux-pinctrl that checks if all involved
gpio/pinctrl devices have a parent that is an i2c adapter in the same
adapter tree that is muxed, and request a "mux-locked mux" if that is the
case.

Modify the select-transfer-deselect code for "mux-locked" muxes so
that each of the select-transfer-deselect ops locks the mux parent
adapter individually.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-05-04 22:39:17 +02:00
Peter Rosin
8320f495cf i2c: allow adapter drivers to override the adapter locking
Add i2c_lock_bus() and i2c_unlock_bus(), which call the new lock_bus and
unlock_bus ops in the adapter. These funcs/ops take an additional flags
argument that indicates for what purpose the adapter is locked.

There are two flags, I2C_LOCK_ROOT_ADAPTER and I2C_LOCK_SEGMENT, but they
are both implemented the same. For now. Locking the root adapter means
that the whole bus is locked, locking the segment means that only the
current bus segment is locked (i.e. i2c traffic on the parent side of
a mux is still allowed even if the child side of the mux is locked).

Also support a trylock_bus op (but no function to call it, as it is not
expected to be needed outside of the i2c core).

Implement i2c_lock_adapter/i2c_unlock_adapter in terms of the new locking
scheme (i.e. lock with the I2C_LOCK_ROOT_ADAPTER flag).

Locking the root adapter and locking the segment is the same thing for
all root adapters (e.g. in the normal case of a simple topology with no
i2c muxes). The two locking variants are also the same for traditional
muxes (aka parent-locked muxes). These muxes traverse the tree, locking
each level as they go until they reach the root. This patch is preparatory
for a later patch in the series introducing mux-locked muxes, which behave
differently depending on the requested locking. Since all current users
are using i2c_lock_adapter, which is a wrapper for I2C_LOCK_ROOT_ADAPTER,
we only need to annotate the calls that will not need to lock the root
adapter for mux-locked muxes. I.e. the instances that needs to use
I2C_LOCK_SEGMENT instead of i2c_lock_adapter/I2C_LOCK_ROOT_ADAPTER. Those
instances are in the i2c_transfer and i2c_smbus_xfer functions, so that
mux-locked muxes can single out normal i2c accesses to its slave side
and adjust the locking for those accesses.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-05-04 22:28:31 +02:00
Wolfram Sang
a16d6ebca6 i2c: introduce helper function to get 8 bit address from a message
Drivers do this in various ways, let's use one standard way of doing it.
Note: I2C_M_RD is bit 0, so the code could be simplified. To be extremly
robust and to advertise good coding practices, I still use the ternary
operator and let the compilers do the optimizing job.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-11 18:54:59 +02:00
Paul Gortmaker
c698d639f7 i2c: create builtin_i2c_driver to avoid registration boilerplate
In commit f309d44431 ("platform_device:
better support builtin boilerplate avoidance") we introduced the
builtin_driver macro.

Here we use that support and extend it to I2C driver registration,
so where a driver is clearly non-modular and builtin-only, we can
register it in a similar fashion.  And existing code that is clearly
non-modular can be updated with the simple mapping of

     module_i2c_driver(...)  ---> builtin_i2c_driver(...)

We've essentially cloned the former to make the latter, and taken
out the remove/module_exit parts since those never get used in a
non-modular build of the code.

A similar thing was done in commit b4eb6cdbbd
("PCI: Add builtin_pci_driver() to avoid registration boilerplate").

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-01-13 11:06:03 +01:00
Wolfram Sang
e1dba01ca6 i2c: add generic routine to parse DT for timing information
Inspired from the i2c-rk3x driver (thanks guys!) but refactored and
extended. See built-in docs for further information.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-12-14 10:51:07 +01:00
Nicola Corna
cfa576db83 i2c: add i2c_check_quirks helper function
This patch adds a i2c_check_quirks helper function to check the quirk flags
of an i2c adapter, in a similar way to i2c_check_functionality.

Signed-off-by: Nicola Corna <nicola@corna.info>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-11-30 18:37:27 +01:00
Nicola Corna
749de3dac5 i2c: add i2c quirk flag for unsupported clock stretching
Add I2C_AQ_NO_CLK_STRETCH quirk flag, to be used when clock stretching is
not supported.

Signed-off-by: Nicola Corna <nicola@corna.info>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-11-30 18:37:24 +01:00
Irina Tirdea
01eef96e37 i2c: core: Add support for best effort block read emulation
There are devices that need to handle block transactions
regardless of the capabilities exported by the adapter.
For performance reasons, they need to use i2c read blocks
if available, otherwise emulate the block transaction with word
or byte transactions.

Add support for a helper function that would read a data block
using the best transfer available: I2C_FUNC_SMBUS_READ_I2C_BLOCK,
I2C_FUNC_SMBUS_READ_WORD_DATA or I2C_FUNC_SMBUS_READ_BYTE_DATA.

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-24 14:05:19 +02:00
Wolfram Sang
c5ebb387f4 i2c: add a flag to mark clients as slaves
And update indentation with one more tab, sigh...

Tested-by: Andrey Danin <danindrey@mail.ru>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-24 14:05:10 +02:00
Vladimir Zapolskiy
48e9743dd6 i2c: core: add and export of_get_i2c_adapter_by_node() interface
of_find_i2c_adapter_by_node() call requires quite often missing
put_device(), and i2c_put_adapter() releases a device locked by
i2c_get_adapter() only. In general module_put(adapter->owner) and
put_device(dev) are not interchangeable.

This is a common error reproduction scenario as a result of the
misusage described above (for clearness this is run on iMX6 platform
with HDMI and I2C bus drivers compiled as kernel modules):

    root@mx6q:~# lsmod | grep i2c
    i2c_imx                10213  0
    root@mx6q:~# lsmod | grep dw_hdmi_imx
    dw_hdmi_imx             3631  0
    dw_hdmi                11846  1 dw_hdmi_imx
    imxdrm                  8674  3 dw_hdmi_imx,imx_ipuv3_crtc,imx_ldb
    drm_kms_helper        113765  5 dw_hdmi,imxdrm,imx_ipuv3_crtc,imx_ldb
    root@mx6q:~# rmmod dw_hdmi_imx
    root@mx6q:~# lsmod | grep i2c
    i2c_imx                10213  -1

                                 ^^^^^

    root@mx6q:~# rmmod i2c_imx
    rmmod: ERROR: Module i2c_imx is in use

To fix existing users of these interfaces and to avoid any further
confusion and misusage in future, add one more interface
of_get_i2c_adapter_by_node(), it is similar to i2c_get_adapter() in
sense that an I2C bus device driver found and locked by user can be
correctly unlocked by i2c_put_adapter().

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-10 08:37:36 +02:00
Linus Torvalds
2481bc7528 Power management and ACPI updates for v4.1-rc1
- Generic PM domains support update including new PM domain
    callbacks to handle device initialization better (Russell King,
    Rafael J Wysocki, Kevin Hilman).
 
  - Unified device properties API update including a new mechanism
    for accessing data provided by platform initialization code
    (Rafael J Wysocki, Adrian Hunter).
 
  - ARM cpuidle update including ARM32/ARM64 handling consolidation
    (Daniel Lezcano).
 
  - intel_idle update including support for the Silvermont Core in
    the Baytrail SOC and for the Airmont Core in the Cherrytrail and
    Braswell SOCs (Len Brown, Mathias Krause).
 
  - New cpufreq driver for Hisilicon ACPU (Leo Yan).
 
  - intel_pstate update including support for the Knights Landing
    chip (Dasaratharaman Chandramouli, Kristen Carlson Accardi).
 
  - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann).
 
  - powernv cpufreq driver update (Shilpasri G Bhat).
 
  - devfreq update including Tegra support changes (Tomeu Vizoso,
    MyungJoo Ham, Chanwoo Choi).
 
  - powercap RAPL (Running-Average Power Limit) driver update
    including support for Intel Broadwell server chips (Jacob Pan,
    Mathias Krause).
 
  - ACPI device enumeration update related to the handling of the
    special PRP0001 device ID allowing DT-style 'compatible' property
    to be used for ACPI device identification (Rafael J Wysocki).
 
  - ACPI EC driver update including limited _DEP support (Lan Tianyu,
    Lv Zheng).
 
  - ACPI backlight driver update including a new mechanism to allow
    native backlight handling to be forced on non-Windows 8 systems
    and a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede).
 
  - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu).
 
  - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
    Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki).
 
  - Fixes related to suspend-to-idle for the iTCO watchdog driver and
    the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu).
 
  - PM tracing support for the suspend phase of system suspend/resume
    transitions (Zhonghui Fu).
 
  - Configurable delay for the system suspend/resume testing facility
    (Brian Norris).
 
  - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki).
 
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Merge tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "These are mostly fixes and cleanups all over, although there are a few
  items that sort of fall into the new feature category.

  First off, we have new callbacks for PM domains that should help us to
  handle some issues related to device initialization in a better way.

  There also is some consolidation in the unified device properties API
  area allowing us to use that inferface for accessing data coming from
  platform initialization code in addition to firmware-provided data.

  We have some new device/CPU IDs in a few drivers, support for new
  chips and a new cpufreq driver too.

  Specifics:

   - Generic PM domains support update including new PM domain callbacks
     to handle device initialization better (Russell King, Rafael J
     Wysocki, Kevin Hilman)

   - Unified device properties API update including a new mechanism for
     accessing data provided by platform initialization code (Rafael J
     Wysocki, Adrian Hunter)

   - ARM cpuidle update including ARM32/ARM64 handling consolidation
     (Daniel Lezcano)

   - intel_idle update including support for the Silvermont Core in the
     Baytrail SOC and for the Airmont Core in the Cherrytrail and
     Braswell SOCs (Len Brown, Mathias Krause)

   - New cpufreq driver for Hisilicon ACPU (Leo Yan)

   - intel_pstate update including support for the Knights Landing chip
     (Dasaratharaman Chandramouli, Kristen Carlson Accardi)

   - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann)

   - powernv cpufreq driver update (Shilpasri G Bhat)

   - devfreq update including Tegra support changes (Tomeu Vizoso,
     MyungJoo Ham, Chanwoo Choi)

   - powercap RAPL (Running-Average Power Limit) driver update including
     support for Intel Broadwell server chips (Jacob Pan, Mathias Krause)

   - ACPI device enumeration update related to the handling of the
     special PRP0001 device ID allowing DT-style 'compatible' property
     to be used for ACPI device identification (Rafael J Wysocki)

   - ACPI EC driver update including limited _DEP support (Lan Tianyu,
     Lv Zheng)

   - ACPI backlight driver update including a new mechanism to allow
     native backlight handling to be forced on non-Windows 8 systems and
     a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede)

   - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu)

   - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
     Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki)

   - Fixes related to suspend-to-idle for the iTCO watchdog driver and
     the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu)

   - PM tracing support for the suspend phase of system suspend/resume
     transitions (Zhonghui Fu)

   - Configurable delay for the system suspend/resume testing facility
     (Brian Norris)

   - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)"

* tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
  ACPI / scan: Fix NULL pointer dereference in acpi_companion_match()
  ACPI / scan: Rework modalias creation when "compatible" is present
  intel_idle: mark cpu id array as __initconst
  powercap / RAPL: mark rapl_ids array as __initconst
  powercap / RAPL: add ID for Broadwell server
  intel_pstate: Knights Landing support
  intel_pstate: remove MSR test
  cpufreq: fix qoriq uniprocessor build
  ACPI / scan: Take the PRP0001 position in the list of IDs into account
  ACPI / scan: Simplify acpi_match_device()
  ACPI / scan: Generalize of_compatible matching
  device property: Introduce firmware node type for platform data
  device property: Make it possible to use secondary firmware nodes
  PM / watchdog: iTCO: stop watchdog during system suspend
  cpufreq: hisilicon: add acpu driver
  ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler
  cpufreq: powernv: Report cpu frequency throttling
  intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs
  intel_idle: Update support for Silvermont Core in Baytrail SOC
  PM / devfreq: tegra: Register governor on module init
  ...
2015-04-14 20:21:54 -07:00
Grygorii Strashko
2b2190a375 i2c: change input parameter to i2c_adapter for prepare/unprepare_recovery
This patch changes type of input parameter for
prepare/unprepare_recovery() callbacks from struct i2c_bus_recovery_info
* to struct i2c_adapter *. This allows to simplify implementation of
these callbacks and avoid type conversations from i2c_bus_recovery_info
to i2c_adapter. The i2c_bus_recovery_info can be simply retrieved from
struct i2c_adapter which contains pointer on it. There are no users
currently, so this is safe to do.

Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-04-10 17:54:31 +02:00
Wolfram Sang
5b77d162a3 i2c: slave: rework the slave API
After more discussion, brave users, and additional datasheet evaluation,
some API updates for the new I2C slave framework became imminent. The
slave events now get some easier to understand naming. Also, the event
handling has been simplified to only need a single call to the slave
callback when an action by the backend is required.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-27 16:53:38 +01:00
Rafael J. Wysocki
ce793486e2 driver core / ACPI: Represent ACPI companions using fwnode_handle
Now that we have struct fwnode_handle, we can use that to point to
ACPI companions from struct device objects instead of pointing to
struct acpi_device directly.

There are two benefits from that.  First, the somewhat ugly and
hackish struct acpi_dev_node can be dropped and, second, the same
struct fwnode_handle pointer can be used in the future to point
to other (non-ACPI) firmware device node types.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
2015-03-16 23:49:03 +01:00
Wolfram Sang
2187f03a95 i2c: add quirk structure to describe adapter flaws
The number of I2C adapters which are not fully I2C compatible is rising,
sadly. Drivers usually do handle the flaws, still the user receives only
some errno for a transfer which normally can be expected to work. This
patch introduces a formal description of flaws. One advantage is that
the core can check before the actual transfer if the messages could be
transferred at all. This is done in the next patch. Another advantage is
that we can pass this information to the user so the restrictions are
exactly known and further actions can be based on that. This will be
done later after some stabilization period for this description.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Ray Jui <rjui@broadcom.com>
Tested-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Tested-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Tested-By: Ludovic Desroches <ludovic.desroches@atmel.com>
2015-03-13 15:09:41 +01:00
Linus Torvalds
295324556c Merge branch 'i2c/for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 "Summary:

   - legacy PM code removed from the core, there were no users anymore
     (thanks to Lars-Peter Clausen)

   - new driver for Broadcom iProc

   - bigger driver updates for designware, rk3x, cadence, ocores

   - a bunch of smaller updates and bugfixes"

* 'i2c/for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (31 commits)
  i2c: ocores: rework clk code to handle NULL cookie
  i2c: designware-baytrail: another fixup for proper Kconfig dependencies
  i2c: fix reference to functionality constants definition
  i2c: iproc: Add Broadcom iProc I2C Driver
  i2c: designware-pci: update Intel copyright line
  i2c: ocores: add common clock support
  i2c: hix5hd2: add COMPILE_TEST
  i2c: clarify comments about the dev_released completion
  i2c: ocores: fix clock-frequency binding usage
  i2c: tegra: Maintain CPU endianness
  i2c: designware-baytrail: use proper Kconfig dependencies
  i2c: designware: Do not calculate SCL timing parameters needlessly
  i2c: do not try to load modules for of-registered devices
  i2c: designware: Add Intel Baytrail PMIC I2C bus support
  i2c: designware: Add i2c bus locking support
  of: i2c: Add i2c-mux-idle-disconnect DT property to PCA954x mux driver
  i2c: designware: use {readl|writel}_relaxed instead of readl/writel
  i2c: designware-pci: no need to provide clk_khz
  i2c: designware-pci: remove Moorestown support
  i2c: imx: whitespace and checkpatch cleanup
  ...
2015-02-21 12:41:50 -08:00
Jean Delvare
d5fd120e78 i2c: Only include slave support if selected
Make the slave support depend on CONFIG_I2C_SLAVE. Otherwise it gets
included unconditionally, even when it is not needed.

I2C bus drivers which implement slave support must select
I2C_SLAVE.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-01-26 22:05:20 +01:00
Lars-Peter Clausen
523c5b8964 i2c: Remove support for legacy PM
There haven't been any I2C driver that use the legacy suspend/resume
callbacks for a while now and new drivers are supposed to use PM ops. So
remove support for legacy suspend/resume for I2C drivers.

Since there aren't any special bus specific things to do during
suspend/resume and since the PM core will automatically fallback directly to
using the device's PM ops if no bus PM ops are specified there is no need to
have any I2C bus PM ops.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-22 20:09:08 +01:00
Linus Torvalds
96895199c8 Merge branch 'i2c/for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 "For 3.19, the I2C subsystem has to offer special candy this time.
  Right in time for Christmas :)

   - I2C slave framework: finally, a generic mechanism for Linux being
     an I2C slave (if the bus driver supports that).  Docs are still
     missing but will come later this cycle, the code is good enough to
     go.
   - I2C muxes represent their topology in sysfs much more detailed.
     This will help users to navigate around much easier.
   - irq population of i2c clients is now done at probe time, not device
     creation time, to have better support for deferred probing.
   - new drivers for Imagination SCB, Amlogic Meson
   - DMA support added for Freescale IMX, Renesas SHMobile
   - slightly bigger driver updates to OMAP, i801, AT91, and rk3x
     (mostly quirk handling, timing updates, and using better kernel
     interfaces)
   - eeprom driver can now write with byte-access (very slow, but OK to
     have)
   - and the bunch of smaller fixes, cleanups, ID updates..."

* 'i2c/for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (56 commits)
  i2c: sh_mobile: remove unneeded DMA mask
  i2c: rcar: add slave support
  i2c: slave-eeprom: add eeprom simulator driver
  i2c: core changes for slave support
  MAINTAINERS: add I2C dt bindings also to I2C realm
  i2c: designware: Fix falling time bindings doc
  i2c: davinci: switch to use platform_get_irq
  Documentation: i2c: Use PM ops instead of legacy suspend/resume
  i2c: sh_mobile: optimize irq entry
  i2c: pxa: add support for SCCB devices
  omap: i2c: don't check bus state IP rev3.3 and earlier
  i2c: s3c2410: Handle i2c sys_cfg register in i2c driver
  i2c: rk3x: add Kconfig dependency on COMMON_CLK
  i2c: omap: add notes related to i2c multimaster mode
  i2c: omap: don't reset controller if Arbitration Lost detected
  i2c: omap: implement workaround for handling invalid BB-bit values
  i2c: omap: cleanup register definitions
  i2c: rk3x: handle dynamic clock rate changes correctly
  i2c: at91: enable probe deferring on dma channel request
  i2c: at91: remove legacy DMA support
  ...
2014-12-14 12:54:40 -08:00
Wolfram Sang
4b1acc4333 i2c: core changes for slave support
Finally(!), make Linux support being an I2C slave. Most of the existing
infrastructure is reused. We mainly add i2c_slave_register/unregister()
calls which tells i2c bus drivers to activate the slave mode. Then, they
also get a callback to report slave events to.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-11 22:25:53 +01:00
Masanari Iida
f353d71f75 treewide: Fix typo in Documentation/DocBook/device-drivers
This patch fix speeling typo found in html files within
Documentation/DocBook/device-drivers.
It is because html files are generated from comments in source,
so I have to fix comments in the source.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2014-11-03 11:53:34 -05:00
Wolfram Sang
17f4a5c47f i2c: move acpi code back into the core
Commit 5d98e61d33 ("I2C/ACPI: Add i2c ACPI operation region support")
renamed the i2c-core module. This may cause regressions for
distributions, so put the ACPI code back into the core.

Reported-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Lan Tianyu <tianyu.lan@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2014-09-25 16:07:15 +02:00
Lan Tianyu
366047515c i2c: rework kernel config I2C_ACPI
Commit da3c6647(I2C/ACPI: Clean up I2C ACPI code and Add CONFIG_I2C_ACPI
config) adds a new kernel config I2C_ACPI and make I2C core built in
when the config is selected. This is wrong because distributions
etc generally compile I2C as a module and the commit broken that.
This patch is to rename I2C_ACPI to ACPI_I2C_OPREGION. New config
only controls ACPI I2C operation region code and depends on I2C=y.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[wsa: removed unrelated change for Kconfig]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-08-19 10:19:39 -05:00
Lan Tianyu
da3c6647ee I2C/ACPI: Clean up I2C ACPI code and Add CONFIG_I2C_ACPI config
Clean up ACPI related code in the i2c core and add CONFIG_I2C_ACPI
to enable I2C ACPI code.

Current there is a race between removing I2C ACPI operation region
and ACPI AML code accessing. So make i2c core built-in if CONFIG_I2C_ACPI
is set.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-06-27 14:50:41 +02:00
Lan Tianyu
5d98e61d33 I2C/ACPI: Add i2c ACPI operation region support
ACPI 5.0 spec(5.5.2.4.5) defines GenericSerialBus(i2c, spi, uart) operation region.
It allows ACPI aml code able to access such kind of devices to implement
some ACPI standard method.

ACPI Spec defines some access attribute to associate with i2c protocol.
AttribQuick 	       	       		Read/Write Quick Protocol
AttribSendReceive			Send/Receive Byte Protocol
AttribByte 			 	Read/Write Byte Protocol
AttribWord				Read/Write Word Protocol
AttribBlock				Read/Write Block Protocol
AttribBytes				Read/Write N-Bytes Protocol
AttribProcessCall			Process Call Protocol
AttribBlockProcessCall			Write Block-Read Block Process Call Protocol
AttribRawBytes 				Raw Read/Write N-BytesProtocol
AttribRawProcessBytes			Raw Process Call Protocol

On the Asus T100TA, Bios use GenericSerialBus operation region to access
i2c device to get battery info.

Sample code From Asus T100TA

    Scope (_SB.I2C1)
    {
        Name (UMPC, ResourceTemplate ()
        {
            I2cSerialBus (0x0066, ControllerInitiated, 0x00061A80,
                AddressingMode7Bit, "\\_SB.I2C1",
                0x00, ResourceConsumer, ,
                )
        })

	...

        OperationRegion (DVUM, GenericSerialBus, Zero, 0x0100)
        Field (DVUM, BufferAcc, NoLock, Preserve)
        {
            Connection (UMPC),
            Offset (0x81),
            AccessAs (BufferAcc, AttribBytes (0x3E)),
            FGC0,   8
        }
	...
     }

     Device (BATC)
     {
         Name (_HID, EisaId ("PNP0C0A"))  // _HID: Hardware ID
         Name (_UID, One)  // _UID: Unique ID
	 ...

            Method (_BST, 0, NotSerialized)  // _BST: Battery Status
            {
                If (LEqual (AVBL, One))
                {
                    Store (FGC0, BFFG)
                    If (LNotEqual (STAT, One))
                    {
                        ShiftRight (CHST, 0x04, Local0)
                        And (Local0, 0x03, Local0)
                        If (LOr (LEqual (Local0, One), LEqual (Local0, 0x02)))
                        {
                            Store (0x02, Local1)
                        }
	...

    }

The i2c operation region is defined under I2C1 scope. _BST method under
battery device BATC read battery status from the field "FCG0". The request
would be sent to i2c operation region handler.

This patch is to add i2c ACPI operation region support. Due to there are
only "Byte" and "Bytes" protocol access on the Asus T100TA, other protocols
have not been tested.

About RawBytes and RawProcessBytes protocol, they needs specific drivers to interpret
reference data from AML code according ACPI 5.0 SPEC(5.5.2.4.5.3.9 and 5.5.2.4.5.3.10).
So far, not found such case and will add when find real case.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-06-27 14:50:40 +02:00
Wolfram Sang
0c17617008 i2c: add deprecation warning for class based instantiation
Class based instantiation can cause noticeable delays when booting. This
mechanism is used when it is not possible to describe slaves on I2C
busses. As we do have other mechanisms, most embedded I2C will not need
classes and for embedded it is explicitly not recommended to use them. Add
a deprecation warning for drivers which want to disable class based
instantiation in the near future to gain boot-up time, so users relying
on this technique can switch to something better. They really should.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-05 17:16:45 +01:00
Ben Dooks
25ee33fb82 i2c: update i2c_algorithm documentation
Add some kerneldoc style documentaton to the i2c_algorithm
structure, and point the master_xfer return codes at the
right place in Documentation/i2c/fault_codes

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-26 22:48:35 +01:00
Stephen Warren
2fac2b891f i2c: Re-instate body of i2c_parent_is_i2c_adapter()
The body of i2c_parent_is_i2c_adapter() is currently guarded by
I2C_MUX. It should be CONFIG_I2C_MUX instead.

Among potentially other problems, this resulted in i2c_lock_adapter()
only locking I2C mux child adapters, and not the parent adapter. In
turn, this could allow inter-mingling of mux child selection and I2C
transactions, which could result in I2C transactions being directed to
the wrong I2C bus, and possibly even switching between busses in the
middle of a transaction.

One concrete issue caused by this bug was corrupted HDMI EDID reads
during boot on the NVIDIA Tegra Seaboard system, although this only
became apparent in recent linux-next, when the boot timing was changed
just enough to trigger the race condition.

Fixes: 3923172b3d ("i2c: reduce parent checking to a NOOP in non-I2C_MUX case")
Cc: Phil Carmody <phil.carmody@partner.samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-14 17:11:13 +01:00
Lars-Peter Clausen
0acc2b3213 i2c: Remove redundant 'driver' field from the i2c_client struct
The 'driver' field of the i2c_client struct is redundant. The same data can be
accessed through to_i2c_driver(client->dev.driver). The generated code for both
approaches in more or less the same.

E.g. on ARM the expression client->driver->command(...) generates

		...
		ldr     r3, [r0, #28]
		ldr     r3, [r3, #32]
		blx     r3
		...

and the expression to_i2c_driver(client->dev.driver)->command(...) generates

		...
		ldr     r3, [r0, #160]
    	ldr     r3, [r3, #-4]
    	blx     r3
		...

Other architectures will generate similar code.

All users of the 'driver' field outside of the I2C core have already been
converted. So this only leaves the core itself. This patch converts the
remaining few users in the I2C core and then removes the 'driver' field from the
i2c_client struct.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-10-03 22:28:31 +02:00
Mika Westerberg
55e71edb81 i2c: move ACPI helpers into the core
This follows what has already been done for the DeviceTree helpers. Move
the ACPI helpers from drivers/acpi/acpi_i2c.c to the I2C core and update
documentation accordingly.

This also solves a problem reported by Jerry Snitselaar that we can't build
the ACPI I2C helpers as a module.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-23 10:22:29 +02:00
Wolfram Sang
687b81d083 i2c: move OF helpers into the core
I2C of helpers used to live in of_i2c.c but experience (from SPI) shows
that it is much cleaner to have this in the core. This also removes a
circular dependency between the helpers and the core, and so we can
finally register child nodes in the core instead of doing this manually
in each driver. So, fix the drivers and documentation, too.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-23 10:22:20 +02:00
Phil Carmody
3923172b3d i2c: reduce parent checking to a NOOP in non-I2C_MUX case
In 0826374 - i2c: Multiplexed I2C bus core support
core i2c code increased in size and complexity even when I2C_MUX
wasn't selected.

Turning this check into a constant NULL in the n case lets the
client functions in be simplified too, not needing to include
never-called calls to the mux-specific helpers.

Signed-off-by: Phil Carmody <phil.carmody@partner.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-07 16:58:08 +02:00
Lars-Peter Clausen
71546300c8 i2c: Make return type of i2c_del_adapter() void
i2c_del_adapter() is usually called from a drivers remove callback. The Linux
device driver model does not allow the remove callback to fail and all resources
allocated in the probe callback need to be freed, as well as all resources which
have been provided to the rest of the kernel(for example a I2C adapter) need to
be revoked. So any function revoking such resources isn't allowed to fail
either. i2c_del_adapter() adheres to this requirement and will never fail. But
i2c_del_adapter()'s return type is int, which may cause driver authors to think
that it can fail. This led to code constructs like:

	ret = i2c_del_adapter(...);
	BUG_ON(ret);

Since i2c_del_adapter() always returns 0 the BUG_ON is never hit and essentially
becomes dead code, which means it can be removed. Making the return type of
i2c_del_adapter() void makes it explicit that the function will never fail and
should prevent constructs like the above from re-appearing in the kernel code.

All callers of i2c_del_adapter() have already been updated in a previous patch
to ignore the return value, so the conversion of the return type from int to
void can be done without causing any build failures.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-02 07:06:17 +02:00
Lars-Peter Clausen
19baba4cb6 i2c: Remove detach_adapter
The detach_adapter callback has been deprecated for quite some time and has no
user left. Keeping it alive blocks other cleanups, so remove it.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-02 07:03:28 +02:00
Viresh Kumar
5f9296ba21 i2c: Add bus recovery infrastructure
Add i2c bus recovery infrastructure to i2c adapters as specified in the i2c
protocol Rev. 03 section 3.1.16 titled "Bus clear".

http://www.nxp.com/documents/user_manual/UM10204.pdf

Sometimes during operation i2c bus hangs and we need to give dummy clocks to
slave device to start the transfer again. Now we may have capability in the bus
controller to generate these clocks or platform may have gpio pins which can be
toggled to generate dummy clocks. This patch supports both.

This patch also adds in generic bus recovery routines gpio or scl line based
which can be used by bus controller. In addition controller driver may provide
its own version of the bus recovery routine.

This doesn't support multi-master recovery for now.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[wsa: changed gpio type to int and minor reformatting]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-03-24 10:30:54 +01:00
Mika Westerberg
907ddf89d0 i2c / ACPI: add ACPI enumeration support
ACPI 5 introduced I2cSerialBus resource that makes it possible to enumerate
and configure the I2C slave devices behind the I2C controller. This patch
adds helper functions to support I2C slave enumeration.

An ACPI enabled I2C controller driver only needs to call acpi_i2c_register_devices()
in order to get its slave devices enumerated, created and bound to the
corresponding ACPI handle.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-11-23 12:23:40 +01:00
David Howells
607ca46e97 UAPI: (Scripted) Disintegrate include/linux
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
2012-10-13 10:46:48 +01:00
Vivien Didelot
0ec13867ef i2c: Correct struct i2c_driver doc about detection
s/address_data/address_list/ in addition to c3813d6.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-10-05 22:23:54 +02:00
Linus Torvalds
6df419e45d Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab:
 "This is the first part of the media patches for v3.6.

  This patch series contain:
   - new DVB frontend: rtl2832
   - new video drivers: adv7393
   - some unused files got removed
   - a selection API cleanup between V4L2 and V4L2 subdev API's
   - a major redesign at v4l-ioctl2, in order to clean it up
   - several driver fixes and improvements."

* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (174 commits)
  v4l: Export v4l2-common.h in include/linux/Kbuild
  media: Revert "[media] Terratec Cinergy S2 USB HD Rev.2"
  [media] media: Use pr_info not homegrown pr_reg macro
  [media] Terratec Cinergy S2 USB HD Rev.2
  [media] v4l: Correct conflicting V4L2 subdev selection API documentation
  [media] Feature removal: V4L2 selections API target and flag definitions
  [media] v4l: Unify selection flags documentation
  [media] v4l: Unify selection flags
  [media] v4l: Common documentation for selection targets
  [media] v4l: Unify selection targets across V4L2 and V4L2 subdev interfaces
  [media] v4l: Remove "_ACTUAL" from subdev selection API target definition names
  [media] V4L: Remove "_ACTIVE" from the selection target name definitions
  [media] media: dvb-usb: print mac address via native %pM
  [media] s5p-tv: Use module_i2c_driver in sii9234_drv.c file
  [media] media: gpio-ir-recv: add allowed_protos for platform data
  [media] s5p-jpeg: Use module_platform_driver in jpeg-core.c file
  [media] saa7134: fix spelling of detach in label
  [media] cx88-blackbird: replace ioctl by unlocked_ioctl
  [media] cx88: don't use current_norm
  [media] cx88: fix a number of v4l2-compliance violations
  ...
2012-07-30 19:03:41 -07:00
Laurent Pinchart
d47726c521 i2c: Add SCCB support
SCCB is a serial communication bus developed by Omnivision. Its 2-wire
mode is very similar to SMBus byte data transactions, but requires the
controller to ignore the ACK bit and to insert a stop condition after
each message.

Add a device SCCB flag and a message stop flag to be passed to
controller drivers.

[JD: Kill rogue definition in go7007 driver.]

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24 14:13:59 +02:00