Commit Graph

16 Commits

Author SHA1 Message Date
Andy Shevchenko 15c566fcff i2c: designware: Add SPDX license tag
Replace short statement in comment with proper SPDX license tag.

Note, for i2c-desingware-slave.c the identifier is chosen
in accordance with MODULE_LICENSE() macro since it is visible to user.
Another point to this choice is that the header seems to be copy'n'paste
from the other file of this very driver.

Acked-by: Luis Oliveira <Luis.Oliveira@synopsys.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-08-20 10:45:45 +02:00
Andy Shevchenko e3ea52b578 i2c: designware: Convert to use struct i2c_timings
Instead of using custom variables and parser, convert the driver to use
the ones provided by I2C core.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-08-08 22:28:52 +02:00
Wolfram Sang 40fce52170 i2c: designware-master: use core to detect 'no zero length' quirk
And don't reimplement in the driver.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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 23:24:50 +02:00
Jarkko Nikula d07bdbc02c i2c: designware: Add debug print for bus speed
Trivial added debug print for dev->clk_freq doesn't necessarily tell the
actual bus speed or mode the controller is operating. For instance it
may indicate 1 MHz Fast Mode Plus or 3.4 MHz High Speed but driver ends up
using 400 kHz Fast Mode due missing timing parameters or missing support
from HW.

Add a debug print that prints the bus speed based on the validated speed
that gets programmed into a HW.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-03 23:06:19 +02:00
Jarkko Nikula 56b637b5b2 i2c: designware: Separate timing parameter setting from HW initalization
Mixed timing parameter validation, calculation and their debug prints
with HW initialization in i2c_dw_init_master() and i2c_dw_init_slave()
as been bothering me some time.

It makes function a little bit unclear to follow, doesn't show what steps
are needed to do only once during probe and what are needed whenever HW
needs to be reinitialized. Also those debug prints show information that
doesn't change runtime and thus are also needlessly printed multiple times
whenever HW is reinitialized.

Thus let the i2c_dw_init_master() and i2c_dw_init_slave() to do only HW
initialization and move out one time parameter setting and debug prints
to separate functions which are called only during probe.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-03 23:06:04 +02:00
Jarkko Nikula 1080ee7e28 i2c: designware: Move SDA hold time configuration to common code
SDA hold time configuration is common to both master and slave code. It
is also something that can be done once during probe and do only
register write when HW needs to be reinitialized.

Remove duplication and move SDA hold time configuration to common code.
It will be called from slave probe and for master code from a new
i2c_dw_set_timings_master() to where we will populate more probe time
timing parameter setting.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-03 23:05:55 +02:00
Jarkko Nikula 3bd4f27727 i2c: designware: Call i2c_dw_clk_rate() only once in i2c_dw_init_master()
This is rather readability update than micro-optimization, or if not
optimization at all. We take the input clock rate to a variable and pass
that to SCL timing parameter calculation functions.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-03 23:05:35 +02:00
Jarkko Nikula 3aca0bd6f4 i2c: designware: Move register access detection to common code
Move register access detection out from master and slave HW
initialization code to common code. Motivation for this is to have
register access configured before HW initialization and remove
duplicated code.

This allows to do further separation between probe time initialization
and runtime reinitialization code.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-03 23:05:20 +02:00
Alexander Monakov 9f4659ba38 i2c: designware: refactor low-level enable/disable
Low-level controller enable function __i2c_dw_enable is overloaded to
also handle disabling. What's worse, even though the documentation
requires polling the IC_ENABLE_STATUS register when disabling, this
is not done: polling needs to be requested specifically by calling
__i2c_dw_enable_and_wait, which can also poll on enabling, but that
doesn't work if the IC_ENABLE_STATUS register is not implemented.
This is quite confusing if not in fact backwards.

Especially since the documentation says that disabling should be
followed by polling, the driver should be using a separate function
where it does one-shot disables to make the optimization stand out.

This refactors the two functions so that requested status is given
in the name rather than in a boolean argument. Specifically:

 - __i2c_dw_enable: enable without polling (in accordance with docs)
 - __i2c_dw_disable: disable and do poll (also as suggested by docs)
 - __i2c_dw_disable_nowait: disable without polling (Linux-specific)

No functional change.

Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
[wsa: fixed blank lines in header file]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-15 10:42:19 +02:00
Alexander Monakov 06cb616b1b i2c: designware: fix poll-after-enable regression
Not all revisions of DW I2C controller implement the enable status register.
On platforms where that's the case (e.g. BG2CD and SPEAr ARM SoCs), waiting
for enable will time out as reading the unimplemented register yields zero.

It was observed that reading the IC_ENABLE_STATUS register once suffices to
avoid getting it stuck on Bay Trail hardware, so replace polling with one
dummy read of the register.

Fixes: fba4adbbf6 ("i2c: designware: must wait for enable")
Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Tested-by: Ben Gardner <gardner.ben@gmail.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2018-05-10 12:30:20 +02:00
Alexander Monakov 7a20e707aa i2c: designware: suppress unneeded SDA hold time warnings
The hardware may not support SDA hold time configuration, but if it is
not set in the Device Tree either, there is no need to print a warning.

Reported-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-17 21:53:01 +01:00
Andy Shevchenko d1fa74520d i2c: designware: Consider SCL GPIO optional
GPIO library can return -ENOSYS for the failed request.
Instead of failing ->probe() in this case override error code to 0.

Fixes: ca382f5b38 ("i2c: designware: add i2c gpio recovery option")
Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-02-22 12:15:35 +01:00
Ben Gardner fba4adbbf6 i2c: designware: must wait for enable
One I2C bus on my Atom E3845 board has been broken since 4.9.
It has two devices, both declared by ACPI and with built-in drivers.

There are two back-to-back transactions originating from the kernel, one
targeting each device. The first transaction works, the second one locks
up the I2C controller. The controller never recovers.

These kernel logs show up whenever an I2C transaction is attempted after
this failure.
i2c-designware-pci 0000:00:18.3: timeout in disabling adapter
i2c-designware-pci 0000:00:18.3: timeout waiting for bus ready

Waiting for the I2C controller status to indicate that it is enabled
before programming it fixes the issue.

I have tested this patch on 4.14 and 4.15.

Fixes: commit 2702ea7dbe ("i2c: designware: wait for disable/enable only if necessary")
Cc: linux-stable <stable@vger.kernel.org> #4.13+
Signed-off-by: Ben Gardner <gardner.ben@gmail.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-02-21 09:15:47 +01:00
Tim Sander ca382f5b38 i2c: designware: add i2c gpio recovery option
This patch contains much input from Phil Reid and has been tested
on Intel/Altera Cyclone V SOC Hardware with Altera GPIO's for the
SCL and SDA GPIO's.

Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Tim Sander <tim@krieglstein.org>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-11-27 18:39:38 +01:00
Jarkko Nikula 21bf440ce1 i2c: designware: Make HW init functions static
Recent i2c-designware slave support patches use master or slave HW init
functions through the function pointer so we can declare them static.

While at it, rename i2c_dw_init() as i2c_dw_init_master().

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Luis Oliveira <lolivei@synopsys.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-07-04 16:11:02 +02:00
Luis Oliveira 90312351fd i2c: designware: MASTER mode as separated driver
- The functions related to I2C master mode of operation were transformed
  in a single driver.
- Common definitions were moved to i2c-designware-core.h
- The i2c-designware-core is now only a library file, the functions
  associated are in a source file called i2c-designware-common and
  are used by both i2c-designware-master and i2c-designware-slave.
- To decrease noise in namespace common i2c_dw_*() functions are
  now using ops to keep them private.
- Designware PCI driver had to be changed to match the previous ops
  functions implementation.

Almost all of the "core" source is now part of the "master" source. The
difference is the functions used by both modes and they are in the
"common" source file.

Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-06-19 18:24:59 +02:00