Specifying the i2c SoC data in an array provides very little benefit and
gets unwieldly / confusing as the array grows since the next bit of code
needs to refer to elements in the array by their raw integral index.
Let's just create a single 'static const' structure for each SoC so that
we can refer to these structures by ID.
Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Suggested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
rk3x_i2c_setup() gets called directly before rk3x_i2c_start(),
and the last thing in setup was to clean the IPD, so no reason
to do it at the beginning of start.
Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The "div_high" and "div_low" values are always used together.
Group them into a structure to make it easier to pass them
both around. This structure also provides a place for future
calculated timings.
Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add kernel-doc documentation for the elements of the previously
undocumented struct rk3x_i2c.
Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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>
.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>
osif_table is never modified, so declare it as const.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
David reported that the length for memset was incorrect (element sizes
were not taken into account). Then I saw that we are clearing kzalloced
memory, so we can simply drop this code.
Reported-by: David Binderman <dcb314@hotmail.com>
Reviewed-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The interrupt handling code makes it look like several status values
may be merged together before being processed, while this will never
happen. Change from bit-wise OR to simple assignment to make it more
obvious and avoid misunderstanding.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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>
of_match_table was not filled which prevents device to be
instantiated from device tree node.
Signed-off-by: Lukasz Gemborowski <lukasz.gemborowski@nokia.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Remove the warning about a too long SMBUS message because
the ipmi_ssif driver triggers this warning too frequently so it
spams the message log.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
During receive the controller requires the AAK flag for all
bytes but the final one. This was wrong in case of I2C_M_RECV_LEN,
where the decision if the final byte is to be transmitted
happened before adding the additional received length byte.
Set the AAK flag if additional bytes are to be received.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Many Intel systems the BIOS declares a SystemIO OpRegion below the SMBus
PCI device as can be seen in ACPI DSDT table from Lenovo Yoga 900:
Device (SBUS)
{
OperationRegion (SMBI, SystemIO, (SBAR << 0x05), 0x10)
Field (SMBI, ByteAcc, NoLock, Preserve)
{
HSTS, 8,
Offset (0x02),
HCON, 8,
HCOM, 8,
TXSA, 8,
DAT0, 8,
DAT1, 8,
HBDR, 8,
PECR, 8,
RXSA, 8,
SDAT, 16
}
There are also bunch of AML methods that that the BIOS can use to access
these fields. Most of the systems in question AML methods accessing the
SMBI OpRegion are never used.
Now, because of this SMBI OpRegion many systems fail to load the SMBus
driver with an error looking like one below:
ACPI Warning: SystemIO range 0x0000000000003040-0x000000000000305F
conflicts with OpRegion 0x0000000000003040-0x000000000000304F
(\_SB.PCI0.SBUS.SMBI) (20160108/utaddress-255)
ACPI: If an ACPI driver is available for this device, you should use
it instead of the native driver
The reason is that this SMBI OpRegion conflicts with the PCI BAR used by
the SMBus driver.
It turns out that we can install a custom SystemIO address space handler
for the SMBus device to intercept all accesses through that OpRegion. This
allows us to share the PCI BAR with the AML code if it for some reason is
using it. We do not expect that this OpRegion handler will ever be called
but if it is we print a warning and prevent all access from the SMBus
driver itself.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=110041
Reported-by: Andy Lutomirski <luto@kernel.org>
Reported-by: Pali Rohár <pali.rohar@gmail.com>
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Pali Rohár <pali.rohar@gmail.com>
Tested-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org
The call to put_i2c_dev() frees "i2c_dev" so there is a use after
free when we call cdev_del(&i2c_dev->cdev).
Fixes: d6760b14d4 ('i2c: dev: switch from register_chrdev to cdev API')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
I stumbled multiple times over 'return_i2c_dev', especially before the
actual 'return res'. It makes the code hard to read, so reanme the
function to 'put_i2c_dev' which also better matches 'get_free_i2c_dev'.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c-dev had never moved away from the older register_chrdev interface to
implement its char device registration. The register_chrdev API has the
limitation of enabling only up to 256 i2c-dev busses to exist.
Large platforms with lots of i2c devices (i.e. pluggable transceivers)
with dedicated busses may have to exceed that limit.
In particular, there are also platforms making use of the i2c bus
multiplexing API, which instantiates a virtual bus for each possible
multiplexed selection.
This patch removes the register_chrdev usage and replaces it with the
less old cdev API, which takes away the 256 i2c-dev bus limitation.
It should not have any other impact for i2c bus drivers or user space.
This patch has been tested on qemu x86 and qemu powerpc platforms with
the aid of a module which adds and removes 5000 virtual i2c busses, as
well as validated on an existing powerpc hardware platform which makes
use of the i2c bus multiplexing API.
i2c-dev busses with device minor numbers larger than 256 have also been
validated to work with the existing i2c-tools.
Signed-off-by: Erico Nunes <erico.nunes@datacom.ind.br>
[wsa: kept includes sorted]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The ARCH name was changed during the review process of the mach, and
this driver was forgotten to be converted. Fix it now.
http://article.gmane.org/gmane.linux.ports.arm.kernel/456331
Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
[wsa: updated commit message slightly]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
When the DMA configuration fails, there is a log reporting that we can't
use DMA and indicating the error number. When booting the kernel, it is
annoying to see this error number. Moreover, people can think something
is going wrong. It is not the case, it means that DMA can't be used but
it doesn't prevent to use i2c.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If NO_DMA=y:
drivers/built-in.o: In function `rcar_i2c_dma_unmap':
i2c-rcar.c:(.text+0x6f06c6): undefined reference to `bad_dma_ops'
drivers/built-in.o: In function `rcar_i2c_dma':
i2c-rcar.c:(.text+0x6f07e2): undefined reference to `bad_dma_ops'
i2c-rcar.c:(.text+0x6f0838): undefined reference to `bad_dma_ops'
Add a dependency on HAS_DMA to fix this.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
New drivers should not use dma_request_slave_channel_reason() but
dma_request_chan(). The former is a macro to the later so this change do
not effect the driver in any way.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c updates from Wolfram Sang:
- Peter Rosin did some major rework on the locking of i2c muxes by
seperating parent-locked muxes and mux-locked muxes.
This avoids deadlocks/workarounds when the mux itself needs i2c
commands for muxing. And as a side-effect, other workarounds in the
media layer could be eliminated. Also, Peter stepped up as the i2c
mux maintainer and will keep an eye on these changes.
- major updates to the octeon driver
- add a helper to the core to generate the address+rw_bit octal and
make drivers use it
- quite a bunch of driver updates
* 'i2c/for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (84 commits)
i2c: rcar: add DMA support
i2c: st: Implement bus clear
i2c: only check scl functions when using generic recovery
i2c: algo-bit: declare i2c_bit_quirk_no_clk_stretch as static
i2c: tegra: disable clock before returning error
[media] rtl2832: regmap is aware of lockdep, drop local locking hack
[media] rtl2832_sdr: get rid of empty regmap wrappers
[media] rtl2832: change the i2c gate to be mux-locked
[media] si2168: change the i2c gate to be mux-locked
iio: imu: inv_mpu6050: change the i2c gate to be mux-locked
i2c: mux: document i2c muxes and elaborate on parent-/mux-locked muxes
i2c: mux: relax locking of the top i2c adapter during mux-locked muxing
i2c: muxes always lock the parent adapter
i2c: allow adapter drivers to override the adapter locking
i2c: uniphier: add "\n" at the end of error log
i2c: mv64xxx: remove CONFIG_HAVE_CLK conditionals
i2c: mv64xxx: use clk_{prepare_enable,disable_unprepare}
i2c: mv64xxx: handle probe deferral for the clock
i2c: mv64xxx: enable the driver on ARCH_MVEBU
i2c: octeon: Add workaround for broken irqs on CN3860
...
Make it possible to transfer i2c message buffers via DMA.
Start/Stop/Sending_Slave_Address and some data is still handled using
the old state machine, it is sending the bulk of the data that is done
via DMA.
The first byte of a transmission and the last two bytes of reception are
sent/received using PIO. This is needed for the HW to have access to the
first byte before DMA transmit and to be able to set the STOP condition
for DMA reception.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: fixed a checkpatch warning]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
>From I2C specifications:
http://www.nxp.com/documents/user_manual/UM10204.pdf
Chapter 3.1.16, when the i2c device held the SDA line low, the master
should send 9 clocks pulses to try to recover.
Signed-off-by: Frederic Pillon <frederic.pillon@st.com>
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
A custom recovery function doesn't need these pointers to be populated
because it may work differently internally.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Peter Griffin <peter.griffin@linaro.org>
i2c_bit_quirk_no_clk_stretch is used in i2c-algo-bit.c only, so
declare it as static.
Signed-off-by: Michele Curti <michele.curti@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Disable clock before returning error in tegra_i2c_init() as its leaves
i2c clock ON in case of error and never turns off again as it will have
unbalanced clock enable/disable
Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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>
Instead of checking for i2c parent adapters for every lock/unlock, simply
override the locking for muxes to always lock/unlock the parent adapter
directly.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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>
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>
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>
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>
The new ARM64 Marvell Armada 7K/8K SoC family is using the same I2C
controller as the 32-bits Marvell EBU SoCs, so this commit allows
mv64xxx to be enabled when ARCH_MVEBU=y.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
CN3860 does not interrupt the CPU when the i2c status changes. If
we get a timeout, and see the status has in fact changed, we know we
have this problem, and drop back to polling.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The IS_ENABLED() macro checks if a Kconfig symbol has been enabled either
built-in or as a module, use that macro instead of open coding the same.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
There is a race between the TWSI interrupt and the condition
that is required before proceeding:
Low-level: interrupt flag bit must be set
High-level controller: valid bit must be clear
If the interrupt comes too early and the condition is not met
the wait will time out, and the transfer is aborted leading
to very poor performance.
To avoid this race retry for the condition ~80 µs later.
The retry is avoided on the very first invocation of
wait_event_timeout() (which tests the condition before entering
the wait and is therefore always wrong in this case).
EEPROM reads on 100kHz i2c now measure ~5.2kB/s, about 1/2 what's
achievable, and much better than the worst-case 100 bytes/sec before.
While at it remove the debug print from the low-level wait function.
Signed-off-by: Peter Swain <pswain@cavium.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Zero-length message support (SMBUS QUICK or i2c) never worked with
the Octeon hardware. Disable SMBUS QUICK support and bail out in
case of a zero-length i2c request.
After this change 'i2c-detect -q' will return an error on Octeon but
the previously reported results were wrong anyway.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The clk_prepare_enable() function can fail so check the return
value and propagate the error in case of a failure.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The driver not always prints the error code in case of a failure but this
information can be very useful for debugging. So let's print if available.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Improve the readability by:
- fixing indentation,
- switching to proper block comments,
- removing spurious blank lines,
- checkpatch: void function return statements are not generally useful,
- checkpatch: braces {} are not necessary for any arm of this
statement,
- checkpatch: missing a blank line after declarations.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cleanup the weird function-level comments and remove obvious
documentation for probe/remove.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If during probe() the s3c24xx_i2c_init() failed, the clock was left in
disabled but prepared state.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
cn78xx has a different interrupt architecture, so we have to manage
the interrupts differently.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use High-Level Controller (HLC) when possible. The HLC can read/write
up to 8 bytes and is completely optional. The most important difference
of the HLC is that it only requires one interrupt for a transfer
(up to 8 bytes) where the low-level read/write requires 2 interrupts
plus one interrupt per transferred byte. Since the interrupts are costly
using the HLC improves the performance. Also, the HLC provides improved
error handling.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
[wsa: fixed trivial checkpatch warnings]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add helper function that reads back a value after writing to
make sure the write is finished and use it in octeon_i2c_write_int().
Signed-off-by: Peter Swain <pswain@cavium.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Switch to the i2c bus recovery framework using generic SCL recovery.
If this fails try to reset the hardware. The recovery is triggered
during START on timeout of the interrupt or failure to reach
the START / repeated-START condition.
The START function is moved to xfer and while at it remove the
xfer debug message (i2c core already provides a debug message
for this).
Signed-off-by: Jan Glauber <jglauber@cavium.com>
[wsa: removed one empty line]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Introduce a function that checks for valid status codes depending
on the phase of a transmit or receive. Also add all existing status
codes and improve error handling for various states.
The Octeon TWSI has an "assert acknowledge" bit (TWSI_CTL_AAK) that
is required to be set in master receive mode until the last byte is
requested. The state check needs to consider if this bit was set.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
