Commit Graph

22 Commits

Author SHA1 Message Date
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