I got a build error today that made me realize that it is not
possible to build a kernel for a SiRF platform without enabling
CONFIG_PRIMA2, since a lot of common code depends on CONFIG_PRIMA2.

This fixes all occurences that appear like common SiRF code.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NMark Brown <broonie@linaro.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NBarry Song <Baohua.Song@csr.com>
Acked-by: NMike Turquette <mturquette@linaro.org>

devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NBarry Song <Baohua.Song@csr.com>

i2c: suppress lockdep warning on delete_device

Since commit 846f9974 the following lockdep
warning is thrown in case i2c device is removed (via delete_device sysfs
attribute) which contains subdevices (e.g. i2c multiplexer):

=============================================
[ INFO: possible recursive locking detected ]
3.8.7-0-sampleversion-fct #8 Tainted: G           O
---------------------------------------------
bash/3743 is trying to acquire lock:
  (s_active#110){++++.+}, at: [<ffffffff802b3048>] sysfs_hash_and_remove+0x58/0xc8

but task is already holding lock:
  (s_active#110){++++.+}, at: [<ffffffff802b3cb8>] sysfs_write_file+0xc8/0x208

other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(s_active#110);
   lock(s_active#110);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

4 locks held by bash/3743:
  #0:  (&buffer->mutex){+.+.+.}, at: [<ffffffff802b3c3c>] sysfs_write_file+0x4c/0x208
  #1:  (s_active#110){++++.+}, at: [<ffffffff802b3cb8>] sysfs_write_file+0xc8/0x208
  #2:  (&adap->userspace_clients_lock/1){+.+.+.}, at: [<ffffffff80454a18>] i2c_sysfs_delete_device+0x90/0x238
  #3:  (&__lockdep_no_validate__){......}, at: [<ffffffff803dcc24>] device_release_driver+0x24/0x48

stack backtrace:
Call Trace:
[<ffffffff80575cc8>] dump_stack+0x8/0x34
[<ffffffff801b50fc>] __lock_acquire+0x161c/0x2110
[<ffffffff801b5c3c>] lock_acquire+0x4c/0x70
[<ffffffff802b60cc>] sysfs_addrm_finish+0x19c/0x1e0
[<ffffffff802b3048>] sysfs_hash_and_remove+0x58/0xc8
[<ffffffff802b7d8c>] sysfs_remove_group+0x64/0x148
[<ffffffff803d990c>] device_remove_attrs+0x9c/0x1a8
[<ffffffff803d9b1c>] device_del+0x104/0x1d8
[<ffffffff803d9c18>] device_unregister+0x28/0x70
[<ffffffff8045505c>] i2c_del_adapter+0x1cc/0x328
[<ffffffff8045802c>] i2c_del_mux_adapter+0x14/0x38
[<ffffffffc025c108>] pca954x_remove+0x90/0xe0 [pca954x]
[<ffffffff804542f8>] i2c_device_remove+0x80/0xe8
[<ffffffff803dca9c>] __device_release_driver+0x74/0xf8
[<ffffffff803dcc2c>] device_release_driver+0x2c/0x48
[<ffffffff803dbc14>] bus_remove_device+0x13c/0x1d8
[<ffffffff803d9b24>] device_del+0x10c/0x1d8
[<ffffffff803d9c18>] device_unregister+0x28/0x70
[<ffffffff80454b08>] i2c_sysfs_delete_device+0x180/0x238
[<ffffffff802b3cd4>] sysfs_write_file+0xe4/0x208
[<ffffffff8023ddc4>] vfs_write+0xbc/0x160
[<ffffffff8023df6c>] SyS_write+0x54/0xd8
[<ffffffff8013d424>] handle_sys64+0x44/0x64

The problem is already known for USB and PCI subsystems. The reason is that
delete_device attribute is defined statically in i2c-core.c and used for all
devices in i2c subsystem.

Discussion of original USB problem:
http://lkml.indiana.edu/hypermail/linux/kernel/1204.3/01160.html

Commit 356c05d5 introduced new macro to suppress
lockdep warnings for this special case and included workaround for USB code.

LKML discussion of the workaround:
http://lkml.indiana.edu/hypermail/linux/kernel/1205.1/03634.html

As i2c case is in principle the same, the same workaround could be used here.
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nsn.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

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: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Duplicate the feature bits documentation in modinfo, as not every user
will read the driver's source code or documentation file.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This is the same controller as on Intel Lynxpoint but the ACPI ID is
different (8086F41). Add support for this.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

If the I2C bus is put to a low power state by an ACPI method it might pull
the SDA line low (as its power is removed). Once the bus is put to full
power state again, the SDA line is pulled back to high. This transition
looks like a STOP condition from the controller point-of-view which sets
STOP detected bit in its status register causing the driver to fail
subsequent transfers.

Fix this by always clearing all interrupts before we start a transfer.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

i2c_dw_xfer_msg() pushes a number of bytes to transmit/receive
to/from the bus into the TX FIFO.
For master-rx transactions, the maximum amount of data that can be
received is calculated depending solely on TX and RX FIFO load.

This is racy - TX FIFO may contain master-rx data yet to be
processed, which will eventually land into the RX FIFO. This
data is not taken into account and the function may request more
data than the controller is actually capable of storing.

This patch ensures the driver takes into account the outstanding
master-rx data in TX FIFO to prevent RX FIFO overrun.
Signed-off-by: NJosef Ahmad <josef.ahmad@linux.intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

The TX_FIFO register is 10 bits wide.  The lower 8 bits are the data to be
written, while the upper two bits are flags to indicate stop/start.

The driver apparently attempted to optimize write access, by only writing a
byte in those cases where the stop/start bits are zero.  However, we have
seen cases where the lower byte is duplicated onto the upper byte by the
hardware, which causes inadvertent stop/starts.

This patch changes the write access to the transmit FIFO to always be 16 bits
wide.

Signed off by: Steven A. Falco <sfalco@harris.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

HZ based value is better than a magic number.
Signed-off-by: NEunbong Song <eunb.song@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

I've been debugging the abnormal operation of i2c on octeon. If a process is
terminated by signal in the middle of i2c operation, next i2c read operation
which is done by another process was failed. So i changed to ignore signal in
the middle of i2c operation. After that the problem was not reproduced.
Signed-off-by: NEunbong Song <eunb.song@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Driver core already takes care of refcounting, no need to do this on
driver level again.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>

Driver core already takes care of refcounting, no need to do this on
driver level again.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>

Driver core already takes care of refcounting, no need to do this on
driver level again.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NSekhar Nori <nsekhar@ti.com>

The i2c-arb-gpio-challenge driver implements an I2C arbitration scheme
where masters need to claim the bus with a GPIO before they can start
a transaction.  This should generally only be used when standard I2C
multimaster isn't appropriate for some reason (errata/bugs).

This driver is based on code that Simon Glass added to the i2c-s3c2410
driver in the Chrome OS kernel 3.4 tree.  The current incarnation as a
mux driver is as suggested by Grant Likely.  See
<https://patchwork.kernel.org/patch/1877311/> for some history.
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NNaveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

GENERIC_GPIO is now equivalent to GPIOLIB and features that depended on
GENERIC_GPIO can now depend on GPIOLIB to allow removal of this option.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>

Use generic DMA DT helper. Platforms booting with or without DT populated are
both supported.
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Acked-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

In PIO mode we can end up with the same errors as in DMA mode, but as IRQs
are disabled there we have to check for them manually after each command.

Also don't use the big controller reset hammer when receiving a NAK from a
slave. It's sufficient to tell the controller to continue at a clean state.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Tested-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This commit fixes the three following races in PIO code:

- The CTRL0 register is racy in itself, when programming transfer state and
  run bit in the same cycle the hardware sometimes ends up using the state
  from the last transfer. Fix this by programming state in one cycle, make
  sure the write is flushed down APBX bus by reading back the reg and only
  then trigger the run bit.

- Only clear the DMAREQ bit in DEBUG0 after the read/write to the data reg
  happened. Otherwise we are racing with the hardware about who touches
  the data reg first.

- When checking for completion of a transfer it's not sufficient to check
  if the data engine finished, but also a check for i2c bus idle is needed.
  In PIO mode we are really fast to program the next transfer after a finished
  one, so the controller possibly tries to start a new transfer while the
  clkgen engine is still busy writing the NAK/STOP from the last transfer to
  the bus.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Using autosuspend helps to reduce the resume latency in situations where
another I2C message is going to be started soon. For example with HID over
I2C touch panels we get several messages in a short period of time while
the touch panel is in use.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This is not an atomic context so there is no need to use mdelay() but
instead use usleep_range().
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The correct way to disable or enable the controller is to wait until the
DW_IC_ENABLE_STATUS register bit matches the bit we program into DW_IC_ENABLE
register. This procedure is described in the DesignWare I2C databook.

By doing this we can be sure that the controller is in correct state once
the function returns.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

It is not good idea to mix static and dynamic I2C adapter numbering. In
this particular case on Lynxpoint we had graphics I2C adapter which took
the first numbers preventing the designware I2C driver from using the
adapter numbers it preferred.

Since Lynxpoint support was just introduced and there is no hardware available
outside Intel we can fix this by switching to use dynamic adapter numbering
instead of static.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This makes the error handling much more simpler than open-coding everything
and in addition makes the probe function smaller an tidier.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

With dev_err() we can get the device instance printed as well and is pretty
much standard to use dev_* macros in the drivers anyway. In addition
correct the indentation of probe() arguments.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This makes the error handling much more simpler than open-coding everything
and in addition makes the probe function smaller and tidier.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

CONFIG_HOTPLUG is going away as an option, cleanup CONFIG_HOTPLUG
ifdefs in i2c files.
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

SMBus read and write are supported by the emulation layer of i2c
framework if the controller doesn't have SMBus features.

I2C_M_RECV_LEN flag is used to let i2c drivers know rx length is not
yet determined but will be read to the first byte in rx buffer.

s3c2410 doesn't handle this flag. So only one byte is read from slave.
There fore following two features are added to the driver code.

1. skip rx length check if I2C_M_RECV_LEN is set and the length is 1.
2. add actual bytes to the rx length after reading first bytes if
   I2C_M_RECV_LEN.

I2C_M_RECV_LEN is only set for SMBus command. So this code does not
affect legacy codes which only use i2c command for s3c2410.
Signed-off-by: NJaemin Yoo <jmin.yoo@samsung.com>
Tested-by: NPrasanna Kumar <prasanna.ps@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

With the generic DMA device tree helper supported by mxs-dma driver,
client devices only need to call dma_request_slave_channel() for
requesting a DMA channel from dmaengine.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NWolfram Sang <wsa@the-dreams.de>

The ACPI handle of struct i2c_adapter's dev member should not be
set, because this causes that struct i2c_adapter to be associated
with the ACPI device node corresponding to its parent as the
second "physical_device", which is incorrect (this happens during
the registration of struct i2c_adapter).  Consequently,
acpi_i2c_register_devices() should use the ACPI handle of the
parent of the struct i2c_adapter it is called for rather than the
struct i2c_adapter's ACPI handle (which should be NULL).

Make that happen and modify the i2c-designware-platdrv driver,
which currently is the only driver for ACPI-enumerated I2C
controller chips, not to set the ACPI handle for the
struct i2c_adapter it creates.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NAaron Lu <aaron.lu@intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NWolfram Sang <wsa@the-dreams.de>

i2c_del_mux_adapter always returns 0 and none of it current users check its
return value anyway. It is also an essential requirement of the Linux device
driver model, that functions which may be called from a device's remove callback
to free resources provided by the device, are not allowed to fail. This is the
case for i2c_del_mux_adapter(), so make its return type void to make the
fact that it won't fail explicit.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

i2c_del_mux_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 its return
value and assume that it will always succeed (which it will). A subsequent
patch will make the return type of i2c_del_mux_adapter() void.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

i2c_del_adapter() is usually called from a drivers remove callback. The Linux
device driver model does not allow the remove callback to fail and all resources
allocated in the probe callback need to be freed, as well as all resources which
have been provided to the rest of the kernel(for example a I2C adapter) need to
be revoked. So any function revoking such resources isn't allowed to fail
either. i2c_del_adapter() adheres to this requirement and will never fail. But
i2c_del_adapter()'s return type is int, which may cause driver authors to think
that it can fail. This led to code constructs like:

	ret = i2c_del_adapter(...);
	BUG_ON(ret);

Since i2c_del_adapter() always returns 0 the BUG_ON is never hit and essentially
becomes dead code, which means it can be removed. Making the return type of
i2c_del_adapter() void makes it explicit that the function will never fail and
should prevent constructs like the above from re-appearing in the kernel code.

All callers of i2c_del_adapter() have already been updated in a previous patch
to ignore the return value, so the conversion of the return type from int to
void can be done without causing any build failures.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

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: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: NBen Hutchings <bhutchings@solarflare.com>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Currently i2c_del_adapter() returns -EINVAL when it gets an adapter which is not
registered. But none of the users of i2c_del_adapter() depend on this behavior,
so for the sake of being able to sanitize the return type of i2c_del_adapter
argue, that the purpose of i2c_del_adapter() is to remove an I2C adapter from
the system. If the adapter is not registered in the first place this becomes a
no-op. So we can return success without having to do anything.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The detach_adapter callback has been deprecated for quite some time and has no
user left. Keeping it alive blocks other cleanups, so remove it.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This eliminates having an #ifdef returning NULL for the case
when OF is disabled.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Acked-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Update the code to use devm_* API so that driver core will manage
resources.
Signed-off-by: NVishwanathrao Badarkhe, Manish <manishv.b@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Since we have generic i2c bus recover routines now, these custom ones
need to be renamed to fix the namespace clash. Proper conversion needs
to be done by someone who has access to the hardware.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

gpio_direction_output() may fail, check for that and deal with it
appropriately. Also log an error message if gpio_request() fails.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NPeter Korsgaard <peter.korsgaard@barco.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>