Commit Graph

85 Commits

Author SHA1 Message Date
Gregory CLEMENT 31184d8c6e i2c: mv64xxx: Apply errata delay only in standard mode
The errata FE-8471889 description has been updated. There is still a
timing violation for repeated start. But the errata now states that it
was only the case for the Standard mode (100 kHz), in Fast mode (400 kHz)
there is no issue.

This patch limit the errata fix to the Standard mode.

It has been tesed successfully on the clearfog (Aramda 388 based board).

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-17 21:20:04 +01:00
Gregory CLEMENT 1534156e99 i2c: mv64xxx: Fix clock resource by adding an optional bus clock
On Armada 7K/8K we need to explicitly enable the bus clock. The bus clock
is optional because not all the SoCs need them but at least for Armada
7K/8K it is actually mandatory.

The binding documentation is updating accordingly.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-01-26 18:51:03 +01:00
Gregory CLEMENT a9e94bb80e i2c: mv64xxx: Remove useless test before clk_disable_unprepare
clk_disable_unprepare() already checks that the clock pointer is valid.
No need to test it before calling it.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-01-26 18:49:45 +01:00
Philipp Zabel 9024ca12ed i2c: mv64xxx: explicitly request exclusive reset control
Commit a53e35db70 ("reset: Ensure drivers are explicit when requesting
reset lines") started to transition the reset control request API calls
to explicitly state whether the driver needs exclusive or shared reset
control behavior. Convert all drivers requesting exclusive resets to the
explicit API call so the temporary transition helpers can be removed.

No functional changes.

Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-i2c@vger.kernel.org
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-08-14 21:40:07 +02:00
Masahiro Yamada 9242e72aae i2c: use dev_get_drvdata() to get private data in suspend/resume hooks
Several drivers call to_platform_device() to get platform_device
and pass it to platform_get_drvdata().  In platform_get_drvdata(),
the platform_device is converted back to struct device again.

Use dev_get_drvdata() to avoid platform_device/device dance.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> (for DesignWare only)
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-07-31 17:03:32 +02:00
Thomas Petazzoni 88ad60c23a i2c: mv64xxx: don't override deferred probing when getting irq
There is no reason to use platform_get_irq() for non-DT probing and
irq_of_parse_and_map() for DT probing. Indeed, platform_get_irq()
works fine for both.

In addition, using platform_get_irq() properly returns -EPROBE_DEFER
when the interrupt controller is not yet available, so instead of
inventing our own error code (-ENXIO), return the one provided by
platform_get_irq().

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-05-16 23:19:00 +02:00
Philipp Zabel 074363a5a0 i2c: mv64xxx: simplify optional reset handling
As of commit bb475230b8 ("reset: make optional functions really
optional"), the reset framework API calls use NULL pointers to describe
optional, non-present reset controls.

This allows to return errors from devm_reset_control_get_optional and to
call reset_control_(de)assert unconditionally.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-03-23 21:40:29 +01:00
Grzegorz Jaszczyk a4f64ae2b5 i2c: mv64xxx: add suspend/resume support
This commit implements suspend/resume support in the mv64xxx I2C
controller driver. There is no need to implement a ->suspend() hook, as
calling mv64xxx_i2c_hw_init() at ->resume() time is enough.

Signed-off-by: Grzegorz Jaszczyk <jaz@semihalf.com>
Reviewed-by: Nadav Haklai <nadavh@marvell.com>
Reviewed-by: Lior Amsalem <alior@marvell.com>
Tested-by: Lior Amsalem <alior@marvell.com>
[Thomas: switch to dev_pm_ops, fix build warning when !PM.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-01-25 22:17:23 +01:00
Thomas Petazzoni f3a36fbdd3 i2c: mv64xxx: remove CONFIG_HAVE_CLK conditionals
When clock support was added to the i2c-mv64xxx, not all clk functions
had stubs when for !CONFIG_HAVE_CLK configurations. However, nowadays,
both "struct clk" and all the clock framework functions have stubs
when CONFIG_HAVE_CLK is not enabled, so it no longer makes sense to
carry such compile-time conditionals in the driver.

This commit was compile tested on both ARM64 (which has both
CONFIG_OF=y and CONFIG_HAVE_CLK=y) and PowerPC c2k_defconfig (which
has CONFIG_OF=y, CONFIG_HAVE_CLK disabled, and the i2c-mv64xxx driver
enabled).

The only non-trivial change is in the mv64xxx_of_config() function,
which was returning -ENODEV unconditionally if CONFIG_HAVE_CLK was
disabled. Simply removing this condition works fine because the first
test done by the function is to verify if drv_data->clk points to a
valid clock, and if it doesn't, we return -ENODEV. When
CONFIG_HAVE_CLK is disabled, devm_clk_get() unconditionally returns
NULL, so mv64xxx_of_config() will return -ENODEV when no clock is
provided, which is the intended behavior.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-27 19:03:15 +02:00
Thomas Petazzoni 70719350ca i2c: mv64xxx: use clk_{prepare_enable,disable_unprepare}
Instead of separately calling clk_prepare()/clk_enable(), use
clk_prepare_enable(), and instead of calling
clk_disable()/clk_unprepare(), use clk_disable_unprepare(). Those
handy shortcuts have been introduced specifically to simplify the
numerous call sites were both functions were called in sequence.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-27 19:03:11 +02:00
Thomas Petazzoni 9f4d6f1642 i2c: mv64xxx: handle probe deferral for the clock
If a clock is registered by a platform driver and not by the
OF_CLK_DECLARE() mechanism, it might show up after the first attempt
to probe i2c-mv64xxx. In order to solve this, we need to handle
-EPROBE_PREFER as a special return value of devm_clk_get(), and return
the same error code from probe().

This gives us three situations:

 - There is no reference to a clock in the DT. In this case,
   devm_clk_get() returns an error that is not -EPROBE_DEFER
   (something like -ENODEV), and we continue the probing without
   enabling the clock.

 - There is a reference to the clock in the DT, and the clock is
   ready. devm_clk_get() returns a valid reference to the clock, and
   we prepare/enable it.

 - There is a reference to the clock in the DT, but the clock is not
   ready. devm_clk_get() returns -EPROBE_DEFER, and we exit from
   probe() with the same error code so that probe() is tried again
   later.

This is needed for Marvell Armada 7K/8K, where the clock driver is a
platform driver.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-27 19:03:02 +02:00
Hans de Goede bba61f50f7 i2c: mv64xxx: The n clockdiv factor is 0 based on sunxi SoCs
According to the datasheets the n factor for dividing the tclk is
2 to the power n on Allwinner SoCs, not 2 to the power n + 1 as it is
on other mv64xxx implementations.

I've contacted Allwinner about this and they have confirmed that the
datasheet is correct.

This commit fixes the clk-divider calculations for Allwinner SoCs
accordingly.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Olliver Schinagl <oliver@schinagl.nl>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2015-11-30 15:54:22 +01:00
Hezi Shahmoon 0729a04977 i2c: mv64xxx: really allow I2C offloading
Commit 00d8689b85 ("i2c: mv64xxx: rework offload support to fix
several problems") completely reworked the offload support, but left a
debugging-related "return false" at the beginning of the
mv64xxx_i2c_can_offload() function. This has the unfortunate consequence
that offloading is in fact never used, which wasn't really the
intention.

This commit fixes that problem by removing the bogus "return false".

Fixes: 00d8689b85 ("i2c: mv64xxx: rework offload support to fix several problems")
Signed-off-by: Hezi Shahmoon <hezi@marvell.com>
[Thomas: reworked commit log and title.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: <stable@vger.kernel.org>
2015-10-22 14:47:45 +02:00
Thomas Petazzoni 00d8689b85 i2c: mv64xxx: rework offload support to fix several problems
Originally, the I2C controller supported by the i2c-mv64xxx driver
requires a lot of software support: an interrupt is generated at each
step of an I2C transaction (after the start bit, after sending the
address, etc.) and the driver is in charge of re-programming the I2C
controller to do the next step of the I2C transaction. This explains
the fairly complex state machine that the driver has.

On Marvell Armada XP and later processors (Armada 375, 38x, etc.), the
I2C controller was extended with a part called the "I2C Bridge", which
allows to offload the I2C transaction completely to the
hardware. Initial support for this mechanism was added in commit
930ab3d403 ("i2c: mv64xxx: Add I2C Transaction Generator support").

However, the implementation done in this commit has two related
issues, which this commit fixes by completely changing how the offload
implementation is done:

 * SMBus read transfers, where there is one write to select the
   register immediately followed in the same transaction by one read,
   were making the processor hang. This was easier visible on the
   Marvell Armada XP WRT1900AC platform using a driver for an I2C LED
   controller, or on other Armada XP platforms by using a simple
   'i2cget' command to read an I2C EEPROM.

 * The implementation was based on the fact that the offload engine
   was re-programmed to transfer each message of an I2C xfer: this
   meant that each message sent with the offload engine was starting
   with a normal I2C start sequence. However, the I2C subsystem
   assumes that all messages belonging to the same xfer will use the
   so-called "repeated start" so that the entire I2C xfer is seen as
   one transfer by the I2C devices and cannot be interrupt by other
   I2C masters on the same bus.

In fact, the "I2C Bridge" allows to offload three types of xfer:

 - xfer of one write message
 - xfer of one read message
 - xfer of one write message followed by one read message

For all other situations, we have to fallback to not using the "I2C
Bridge" in order to get proper I2C semantics.

Therefore, this commit reworks the offload implementation to put it
not at the message level, but at the xfer level: in the
mv64xxx_i2c_xfer() function, we decide if the transaction can be
offloaded (in which case it is handled by the
mv64xxx_i2c_offload_xfer() function), or otherwise it is handled by
the slow path (implemented in the existing mv64xxx_i2c_execute_msg()).

This allows to simplify the state machine, which no longer needs to
have any state related to the offload implementation: the offload
implementation is now completely separated from the slow path (with
the exception of the interrupt handler, of course).

In summary:

 - mv64xxx_i2c_can_offload() will analyze an I2C xfer and decided of
   the "I2C Bridge" can be used to offload it or not.

 - mv64xxx_i2c_offload_xfer() will actually program the "I2C Bridge"
   to offload one xfer (of either one or two messages), and block
   using mv64xxx_i2c_wait_for_completion() until the xfer completes.

 - The interrupt handler mv64xxx_i2c_intr() is modified to push the
   offload related code to a separate function,
   mv64xxx_i2c_intr_offload(). It will take care of reading the
   received data if needed.

This commit was tested on:

 - Armada XP OpenBlocks AX3-4 (EEPROM on I2C and RTC on I2C)
 - Armada XP WRT1900AC (LED controller on I2C)
 - Armada XP GP (EEPROM on I2C)

Fixes: 930ab3d403 ("i2c: mv64xxx: Add I2C Transaction Generator support")
Cc: <stable@vger.kernel.org> # v3.12+
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
[wsa: fixed checkpatch warnings]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-17 19:26:03 +01:00
Thomas Petazzoni 12598695c2 i2c: mv64xxx: use BIT() macro for register value definitions
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-17 19:25:55 +01:00
Wolfram Sang 1ecc4335eb i2c: busses: drop owner assignment from platform_drivers
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-20 16:20:37 +02:00
Chen-Yu Tsai 0ce4bc1dbd i2c: mv64xxx: continue probe when clock-frequency is missing
The "clock-frequency" DT property is listed as optional, However,
the current code stores the return value of of_property_read_u32 in
the return code of mv64xxx_of_config, but then forgets to clear it
after setting the default value of "clock-frequency". It is then
passed out to the main probe function, resulting in a probe failure
when "clock-frequency" is missing.

This patch checks and then throws away the return value of
of_property_read_u32, instead of storing it and having to clear it
afterwards.

This issue was discovered after the property was removed from all
sunxi DTs.

Fixes: 4c730a06c1 ("i2c: mv64xxx: Set bus frequency to 100kHz if clock-frequency is not provided")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Cc: stable@vger.kernel.org
Acked-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-09-02 12:34:08 +02:00
Wolfram Sang 8c49086cc5 i2c: i2c-mv64xxx: Drop class based scanning to improve bootup time
This driver has been flagged to drop class based instantiation. The removal
improves boot-up time and is unneeded for embedded controllers. Users have been
warned to switch for some time now, so we can actually do the removal. Keep the
DEPRECATED flag, so the core can inform users that the behaviour finally
changed now. After another transition period, this flag can go, too.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-07-16 23:00:01 +02:00
Maxime Ripard 5ed9d92f1b i2c: mv64xxx: Change i2c compatibles for sunxi
The Allwinner A10 compatibles were following a slightly different compatible
patterns than the rest of the SoCs for historical reasons. Move to the other
pattern for consistency across all Allwinner Socs.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
[wsa: dropped binding OK as per
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-February/229438.html]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-05-22 10:09:21 +02:00
Wolfram Sang 5fe29d493f i2c: i2c-mv64xxx: deprecate class based instantiation
Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-28 08:54:26 +01:00
Maxime Ripard f2a67d0c27 i2c: mv64xxx: Fix reset controller handling
The reset framework recently gained optional stubs when CONFIG_RESET_CONTROLLER
is not selected. It also introduced a function reset_get_optional, that is also
dummy-defined whenever the framework isn't enabled, for drivers that needs an
optional reset controller.

Switch to this function, since the mv64xxx driver is in this case. This also
fixes a compilation breakage whenever the reset framework wasn't selected:

drivers/i2c/busses/i2c-mv64xxx.c:771:2: error: implicit declaration of function 'devm_reset_control_get'

While we're at it, remove the redundant test on dev.of_node surrounding the
calls to reset framework functions, since it will either be a valid pointer, an
error pointer in the case where we called reset_get_optional without an of_node
pointer or if it failed, or NULL if we're not loaded through DT.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-28 08:47:32 +01:00
Wolfram Sang 485ecdf1f4 i2c: mv64xxx: refactor initialization for new msgs
We now have a central place to put this code to.

Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-10 17:23:23 +01:00
Wolfram Sang b0200abeba i2c: mv64xxx: directly call send_start when initializing transfer
Calling the state machine with a definite state which is only used in
this context is superfluous. Do it directly.

Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-10 17:23:20 +01:00
Wolfram Sang 4c5b38e881 i2c: mv64xxx: refactor send_start
For start and restart, we are doing the same thing. Let's consolidate
that.

Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-10 17:19:48 +01:00
Maxime Ripard c7dcb1fec0 i2c: mv64xxx: Add support for the Allwinner A31 I2C driver
The Allwinner A31 I2C controller is almost identical to the one used in the
other Allwinner SoCs, except for the fact that it needs to clear the interrupt
by setting the INT_FLAGS bit in the control register, instead of clearing it.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-05 17:30:11 +01:00
Maxime Ripard 370136bc67 i2c: mv64xxx: Add reset deassert call
The Allwinner A31 SoC using that IP has a reset controller maintaining
it reset unless told otherwise.

Add some optional reset support to the driver.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-05 17:29:19 +01:00
Wolfram Sang 79970db213 i2c: mv64xxx: refactor message start to ensure proper initialization
Because the offload mechanism can fall back to a standard transfer,
having two seperate initialization states is unfortunate. Let's just
have one state which does things consistently. This fixes a bug where
some preparation was missing when the fallback happened. And it makes
the code much easier to follow. To implement this, we put the check
if offload is possible at the top of the offload setup function.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Cc: stable@vger.kernel.org # v3.12+
Fixes: 930ab3d403 (i2c: mv64xxx: Add I2C Transaction Generator support)
2014-02-15 15:42:31 +01:00
Gregory CLEMENT 6cf70ae928 i2c: mv64xxx: Fix bus hang on A0 version of the Armada XP SoCs
The first variants of Armada XP SoCs (A0 stepping) have issues related
to the i2c controller which prevent to use the offload mechanism and
lead to a kernel hang during boot.

The commit introduces a new the compatible string
marvell,mv78230-a0-i2c for the i2c controller. When this compatible
string is used the driver disables the offload mechanism and the
kernel no more hangs on these SoCs.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reported-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: stable@vger.kernel.org # v3.12+: af8d1c63afcb: ARM: mvebu: Add support to get the ID and the revision of a SoC
Cc: stable@vger.kernel.org # v3.12+: 85e618a1be2b: ARM: mvebu: Add quirk for i2c for the OpenBlocks AX3-4 board
Cc: stable@vger.kernel.org # v3.12+
Fixes: 930ab3d403 (i2c: mv64xxx: Add I2C Transaction Generator support)
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-01-14 02:01:09 +00:00
Sachin Kamat 4e9053231a i2c: remove redundant of_match_ptr
The data structure of_match_ptr() protects is always compiled in.
Hence of_match_ptr() is not needed.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-10-03 22:00:41 +02:00
Thierry Reding 85b3a9356e i2c: mv64xxx: Do not use writel_relaxed()
The driver is used on PowerPC which don't provide writel_relaxed(). This
breaks the c2k and prpmc2800 default configurations. To fix the build,
turn the calls to writel_relaxed() into writel(). The impacts for ARM
should be minimal.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-09-27 18:12:30 +02:00
Thierry Reding c1a9946780 i2c: mv64xxx: Fix some build warnings
Some functions and variables are only used if the configuration selects
HAVE_CLK. Protect them with a corresponding #ifdef CONFIG_HAVE_CLK block
to avoid compiler warnings.

Signed-off-by: Thierry Reding <treding@nvidia.com>
[wsa: added marker to #endif]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-09-27 18:12:30 +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
Gregory CLEMENT c1d15b68aa i2c: mv64xxx: Fix timing issue on Armada XP (errata FE-8471889)
All the Armada XP (mv78230, mv78260 and mv78460) have a silicon issue
in the I2C controller which violate the i2c repeated start
timing. The I2C standard requires a minimum of 4.7us for the repeated
start condition whereas the I2C controller of the Armada XP this time
is 2.9us.

So this patch adds a 5us delay for the start case only if the
the compatible i2c-mv78230 is set.

Based on the initals patches from Zbigniew Bodek

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Zbigniew Bodek <zbb@semihalf.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-23 10:15:51 +02:00
Gregory CLEMENT 930ab3d403 i2c: mv64xxx: Add I2C Transaction Generator support
The I2C Transaction Generator offloads CPU from managing I2C
transfer step by step.

This feature is currently only available on Armada XP, so usage of
this mechanism is activated through device tree.

Based on the work of Piotr Ziecik and rewrote to use the new way of
handling multiples i2c messages.

Signed-off-by: Piotr Ziecik <kosmo@semihalf.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-23 10:15:50 +02:00
Jingoo Han 6d4028c644 i2c: use dev_get_platdata()
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-19 19:46:30 +02:00
Gregory CLEMENT 4c730a06c1 i2c: mv64xxx: Set bus frequency to 100kHz if clock-frequency is not provided
This commit adds checking whether clock-frequency property acquisition
has succeeded. If not, the frequency is set to 100kHz by default.

The Device Tree binding documentation is updated accordingly.

Based on the intials patches from Zbigniew Bodek

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Zbigniew Bodek <zbb@semihalf.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-25 23:43:37 +02:00
Guenter Roeck 6faa353559 i2c: mv64xxx: Fix transfer error code
The driver returns -ENODEV as error code if it did not get an ACK
from the device. Per Documentation/i2c/fault-codes, it should
return -ENXIO.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-25 18:42:19 +02:00
Maxime Ripard 3d66ac7d81 i2c: mv64xxx: Add Allwinner sun4i compatible
Add the compatible string for the Allwinner A10 i2c controller and the
associated register layout.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-15 13:37:48 +02:00
Maxime Ripard 004e8ed7cc i2c: mv64xxx: make the registers offset configurable
The Allwinner i2c controller uses the same logic as the Marvell one, but
with slightly different register offsets.

Introduce a structure that will be passed by either the pdata or
associated to the compatible strings, and that holds the various
registers that might be needed.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-15 13:37:40 +02:00
Maxime Ripard 683e69b8bb i2c: mv64xxx: Add macros to access parts of registers
These macros make it more comprehensive to access to useful masked and
shifted area of the various registers used.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-15 13:37:39 +02:00
Russell King 4243fa0bad I2C: mv64xxx: fix race between FSM/interrupt and process context
Asking for a multi-part message to be handled by this driver is racy; it
has been observed that the following sequence is possible with this
driver:

	- send start
	- send address + write
	- send data
	- send (repeated) start
	- send address + write
	- send (repeated) start
	- send address + read
	- unrecoverable bus hang (except by system reset)

The problem is that the interrupt handling sees the next event after the
first repeated start is sent - the IFLG bit is set in the register even
though INTEN is disabled.

Let's fix this by moving all of the message processing into interrupt
context, rather than having it partly in IRQ and partly in process
context.  This allows us to move immediately to the next message in the
interrupt handler and get on with the transfer, rather than incuring a
couple of scheduling switches to get the next message.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-05 23:06:48 +02:00
Russell King 3420afbc06 I2C: mv64xxx: move mv64xxx_i2c_prepare_for_io()
Move mv64xxx_i2c_prepare_for_io() higher up in the driver to avoid a
future forward declaration for this function.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-05 23:06:47 +02:00
Russell King aa6bce5319 I2C: mv64xxx: remove I2C_M_NOSTART code
As this driver does not advertise protocol mangling support
(I2C_FUNC_PROTOCOL_MANGLING is not set), having code to act on
I2C_M_NOSTART is illogical, and in any case isn't supportable on
anything but the first message - which makes no sense.  Remove
the I2C_M_NOSTART code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-05 23:06:47 +02:00
Russell King 0c195afb87 I2C: mv64xxx: fix error handling for request_irq()
Propagate the error code from request_irq() rather than ignoring it
entirely.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-05 23:06:46 +02:00
Russell King 2c91110304 I2C: mv64xxx: use devm_kzalloc()
As we're changing to using devm_* APIs to fix various problems
in this driver, lets also do devm_kzalloc() while we're here too.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-05 23:06:45 +02:00
Russell King 4c5c95f53b I2C: mv64xxx: use devm_clk_get() to avoid missing clk_put()
This driver forgets to use clk_put().  Rather than adding clk_put(),
lets instead use devm_clk_get() to obtain this clock so that it's
automatically handled on cleanup.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-05 23:06:44 +02:00
Russell King 16874b0709 I2C: mv64xxx: use devm_ioremap_resource()
Eliminate reg_base_p and reg_size, mv64xxx_i2c_unmap_regs() and an
unchecked ioremap() return from this driver by using the devm_*
API for requesting and ioremapping resources.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-05 23:06:43 +02:00
Russell King d5ac456144 I2C: mv64xxx: use return value from mv64xxx_i2c_map_regs()
mv64xxx_i2c_map_regs() already returns an error code, so lets
propagate that to mv64xxx_i2c_probe()'s caller.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-05 23:06:29 +02:00
Russell King d295a86eab i2c: mv64xxx: work around signals causing I2C transactions to be aborted
Do not use interruptible waits in an I2C driver; if a process uses
signals (eg, Xorg uses SIGALRM and SIGPIPE) then these signals can
cause the I2C driver to abort a transaction in progress by another
driver, which can cause that driver to fail.  I2C drivers are not
expected to abort transactions on signals.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-05-17 22:49:37 +02:00
Lars-Peter Clausen bf51a8c5e0 i2c: Ignore return value of i2c_del_adapter()
i2c_del_adapter() always returns 0. So all checks testing whether it will be
non zero will always evaluate to false and the conditional code is dead code.
This patch updates all callers of i2c_del_mux_adapter() to ignore the return
value and assume that it will always succeed (which it will). In a subsequent
patch the return type of i2c_del_adapter() will be made void.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-02 07:06:03 +02:00