Commit Graph

31 Commits

Author SHA1 Message Date
Ard Biesheuvel 1eace8344c i2c: add param sanity check to i2c_transfer()
The API docs describe i2c_transfer() as taking a pointer to an array
of i2c_msg containing at least 1 entry, but leaves it to the individual
drivers to sanity check the msgs and num parameters. Let's do this in
core code instead.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[wsa: changed '<= 0' to '< 1']
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-11 23:33:46 +02:00
Davidlohr Bueso 50888b015d i2c: Update i2c_trace_msg static key to modern api
No changes in refcount semantics -- key init is false; replace

static_key_slow_inc|dec   with   static_branch_inc|dec
static_key_false          with   static_branch_unlikely

Added a '_key' suffix to i2c_trace_msg, for better self
documentation.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-03 19:20:26 +02:00
Ahbong Chang 4a3f7691e2 i2c: fix parameter of trace_i2c_result
According to the event i2c_result defined in include/trace/events/i2c.h,
the second parameter should be the number of messages instead of the
ended loop index. The value of ended loop index is the same as ret.

Signed-off-by: Ahbong Chang <cwahbong@google.com>
Reviewed-by: Todd Poynor <toddpoynor@google.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-03 16:37:45 +02:00
Wolfram Sang 398432edde i2c: make i2c_check_addr_validity() static
After previous refactoring, there is only one user in the same file
left. Make the function static now.

[wsa: added 'int' to bare 'unsigned']
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 14:07:23 +01:00
Wolfram Sang 8efb11adee Merge branch 'i2c-mux/for-next' of https://github.com/peda-r/i2c-mux into i2c/for-4.17
"These patches verify the device id of the PCA984x mux chips using
standardized (but rarely implemented) i2c device identification."
2018-03-17 21:11:23 +01:00
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
Javier Martinez Canillas af503716ac i2c: core: report OF style module alias for devices registered via OF
The buses should honor the firmware interface used to register the device,
but the I2C core reports a MODALIAS of the form i2c:<device> even for I2C
devices registered via OF.

This means that user-space will never get an OF stype uevent MODALIAS even
when the drivers modules contain aliases exported from both the I2C and OF
device ID tables. For example, an Atmel maXTouch Touchscreen registered by
a DT node with compatible "atmel,maxtouch" has the following module alias:

$ cat /sys/class/i2c-adapter/i2c-8/8-004b/modalias
i2c:maxtouch

So udev won't be able to auto-load a module for an OF-only device driver.
Many OF-only drivers duplicate the OF device ID table entries in an I2C ID
table only has a workaround for how the I2C core reports the module alias.

This patch changes the I2C core to report an OF related MODALIAS uevent if
the device was registered via OF. So for the previous example, after this
patch, the reported MODALIAS for the Atmel maXTouch will be the following:

$ cat /sys/class/i2c-adapter/i2c-8/8-004b/modalias
of:NtrackpadT<NULL>Catmel,maxtouch

NOTE: This patch may break out-of-tree drivers that were relying on this
      behavior, and only had an I2C device ID table even when the device
      was registered via OF. There are no remaining drivers in mainline
      that do this, but out-of-tree drivers have to be fixed and define
      a proper OF device ID table to have module auto-loading working.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Dmitry Mastykin <mastichi@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-05 16:25:32 +01:00
Linus Torvalds 4141cf676b Merge branch 'i2c/for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 "I2C has the following changes for you:

   - new flag to mark DMA safe buffers in i2c_msg. Also, some
     infrastructure around it. And docs.

   - huge refactoring of the at24 driver led by the new maintainer
     Bartosz

   - update I2C bus recovery to send STOP after recovery

   - conversion from gpio to gpiod for I2C bus recovery

   - adding a fault-injector to the i2c-gpio driver

   - lots of small driver improvements, and bigger ones to
     i2c-sh_mobile"

* 'i2c/for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (99 commits)
  i2c: mv64xxx: Add myself as maintainer for this driver
  i2c: mv64xxx: Fix clock resource by adding an optional bus clock
  i2c: mv64xxx: Remove useless test before clk_disable_unprepare
  i2c: mxs: use true and false for boolean values
  i2c: meson: update doc description to fix build warnings
  i2c: meson: add configurable divider factors
  dt-bindings: i2c: update documentation for the Meson-AXG
  i2c: imx-lpi2c: add runtime pm support
  i2c: rcar: fix some trivial typos in comments
  i2c: davinci: fix the cpufreq transition
  i2c: rk3x: add proper kerneldoc header
  i2c: rk3x: account for const type of of_device_id.data
  i2c: acorn: remove outdated path from file header
  i2c: acorn: add MODULE_LICENSE tag
  i2c: rcar: implement bus recovery
  i2c: send STOP after successful bus recovery
  i2c: ensure SDA is released in recovery if SDA is controllable
  i2c: add 'set_sda' to bus_recovery_info
  i2c: add identifier in declarations for i2c_bus_recovery
  i2c: make kerneldoc about bus recovery more precise
  ...
2018-02-04 10:57:43 -08:00
Lixin Wang e0638fa400 i2c: core: decrease reference count of device node in i2c_unregister_device
Reference count of device node was increased in of_i2c_register_device,
but without decreasing it in i2c_unregister_device. Then the added
device node will never be released. Fix this by adding the of_node_put.

Signed-off-by: Lixin Wang <alan.1.wang@nokia-sbell.com>
Tested-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2018-01-17 15:23:31 +01:00
Wolfram Sang 2806e6ad77 i2c: send STOP after successful bus recovery
If we managed to get a client release SDA again, send a STOP afterwards
to make sure we have a consistent state on the bus again.

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 00:04:42 +01:00
Wolfram Sang 72b08fcc15 i2c: ensure SDA is released in recovery if SDA is controllable
If we have a function to control SDA, we should ensure that SDA is not
held down by us. So, release the GPIO in this case.

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 00:04:30 +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 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 10c9ef045a i2c: core: fix compile issue related to incorrect gpio header
The correct header to include for the gpiod interface is
<linux/gpio/consumer.h>.

Fixes: 3991c5c80b ("i2c: Switch to using gpiod interface for gpio bus recovery")
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>
2017-11-28 10:44:00 +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
Andy Shevchenko 7b43dd19c9 i2c: Make i2c_unregister_device() NULL-aware
It's a common pattern to be NULL-aware when freeing resources.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-11-02 00:00:28 +01:00
Wolfram Sang f6d2953643 Merge branch 'i2c/sbs-manager' into i2c/for-4.15 2017-11-01 23:49:36 +01:00
Phil Reid f8756c67b3 i2c: core: call of_i2c_setup_smbus_alert in i2c_register_adapter
Add a call to of_i2c_setup_smbus_alert when a i2c adapter is registered
so the the smbalert driver can be registered.

Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-10-28 23:42:58 +02:00
Claudio Foellmi 1f35b86536 i2c: generic recovery: check SCL before SDA
Move the check for a stuck SCL before the check for a high SDA.
This prevent false positives in the specific case that SDA is fine
and SCL is stuck, which previously returned 0.

Also check SDA again after the loop, if we can.
Together, these changes should lead to a lot more failed
recoveries being caught and returning error codes.

Signed-off-by: Claudio Foellmi <claudio.foellmi@ergon.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-10-28 22:56:50 +02:00
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
Javier Martinez Canillas f4b17a14fa i2c: core: Make comment about I2C table requirement to reflect the code
I2C drivers were required to have an I2C device ID table even if were for
devices that would only be registered using a specific firmware interface
(e.g: OF or ACPI).

But commit da10c06a04 ("i2c: Make I2C ID tables non-mandatory for DT'ed
devices") changed the I2C core to relax the requirement and allow drivers
to avoid defining this table.

Unfortunately it only took into account drivers for OF-only devices and
forgot about ACPI-only ones, and this was fixed by commit c64ffff7a9
("i2c: core: Allow empty id_table in ACPI case as well").

But the latter didn't update the original comment, so it doesn't reflect
what the code does now.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-08-14 21:33:46 +02:00
Andy Shevchenko c64ffff7a9 i2c: core: Allow empty id_table in ACPI case as well
For now empty ID table is not allowed with ACPI and prevents driver to
be probed.

Add a check to allow empty ID table.

This introduces a helper i2c_acpi_match_device().

Note, we rename some static function in i2c-core-acpi.c to distinguish
with public API.

Fixes: da10c06a04 ("i2c: Make I2C ID tables non-mandatory for DT'ed devices")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Rajmohan Mani <rajmohan.mani@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[wsa: needed to get some drivers probed again]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-07-31 15:50:33 +02:00
Wolfram Sang 61e3d0f79d i2c: reformat core-base file header
Finally, apply modern comment rules to the file header. The old style
looked very non-Linuxish and challenged my eyes for some time now. I
also added my own copyright for the period of me being the maintainer.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-05-31 21:01:06 +02:00
Wolfram Sang 16210d0692 i2c: remove unneeded includes from core
They seem like cruft to me. I couldn't find any evidence that something
included from there is actually used.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-05-31 21:01:05 +02:00
Wolfram Sang 53f8f7c5cf i2c: break out ACPI support into separate file
Removes some ifdeffery. Also add the new file to the relevant
MAINTAINERS section.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-05-31 21:01:04 +02:00
Wolfram Sang 5bf4fa7dae i2c: break out OF support into separate file
Also removes some ifdeffery.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-05-31 21:01:04 +02:00
Wolfram Sang 22c78d1cce i2c: break out smbus support into separate file
Break out the exported SMBus functions and the emulation layer into a
separate file. This also involved splitting up the tracing header into
an I2C and an SMBus part.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-05-31 21:01:03 +02:00
Wolfram Sang e4991ecdc6 i2c: break out slave support into separate file
Also removes some ifdeffery.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-05-31 21:01:03 +02:00
Wolfram Sang 91ed53491f i2c: rename core source file to allow refactorization
The I2C core became quite huge and its monolithic structure makes
maintenance hard. So, prepare to break out some functionality into
separate files by renaming the source file. Note that we keep the
resulting object name constant to avoid regressions.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-05-31 21:01:03 +02:00