'commit 2637e5fd ("i2c: octeon: Fix i2c fail problem when a process is
terminated by a signal")' removed the wait_event_interruptible_timeout to
prevent half/mixed i2c messages from being sent/recievd but forgot to
drop the signal handling case in the return handling. This just removes
this dead code. While at it the return variable is adjusted to the type
expected.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

There are several cases where current clock configuration algorithm produces
not optimal results:
- truncation in "clk" calculation leads to the fact that actual BUS frequency
  will be always higher than spec except two exact module frequences 8MHz and
  12MHz in the whole 7-12MHz range of permitted frequences
- driver configures SCL HIGH to LOW ratio always 1 to 1 and this doesn't work
  well in 400kHz case, namely minimum time of LOW state (according to I2C Spec
  2.1) 1.3us will not be fulfilled. HIGH to LOW ratio 1 to 2 would be more
  approriate here.
Signed-off-by: Michael Lawnick <michael.lawnick@nokia.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

pca9541 and pca954x are calling master_xfer() of the parent adapter directly
thus bypassing the quirks checks of the adapter. Use __i2c_transfer() instead.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: Łukasz Gemborowski <lukasz.gemborowski@nokia.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Fixes: b7f62584 ("i2c: add quirk checks to core")

Newly introduced quirks infrastructure doesn't work for the devices behind
MUXes because MUX's master_xfer() calls parent's master_xfer() directly
without checking the quirks. Instead of duplicating check code in MUX just
call __i2c_transfer() instead. This has a side effect on tracing (messages
will appear on both MUX bus and parent bus), but maybe that's not bad at
the end.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: Łukasz Gemborowski <lukasz.gemborowski@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Fixes: b7f62584 ("i2c: add quirk checks to core")

Inherit parent adapter quirks in MUX in case the devices on the multiplexed
buses are interested in the adapter limitations.
Signed-off-by: Łukasz Gemborowski <lukasz.gemborowski@nokia.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Fixes: b7f62584 ("i2c: add quirk checks to core")

The datasheet mentions on page 31 that the bits 10-31 must be read as
don't care and written as 0.
https://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf

We cannot guarantee that we read bits 10-31 as always 0 (because the
datasheet says read as don't care). We clear the bits with a bitmask to
prevent writing back unknown data at the reserved bits.
Signed-off-by: Silvan Wicki <linux_wi@tinag.ch>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This is now done in the I2C driver.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This used to be in platform init code. We want it to do in the driver
now. This is basically a code move and a new compatible added.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

buf_len is a size_t, so unsigned, but was tested with '<= 0'.
Reported-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Fix section mismatch error during kernel build for xgene_slimpro_i2c_probe
function. It was incorrectly defined with __init declaration.
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Sending a message to own address locks the controller up in very bizarre state,
it behaves as slave even if MDR register clearly states master. The controller
remains in this state until reset. To avoid unnecessary timeouts simply avoid
sending to own address. The controller cannot do this any way. Also, do not
enable AAS IRQ, as the slave mode is not supported by the driver and the only
possibility to trigger this IRQ is to send to own address.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

There are several problems in the function:
- "to_cnt" variable does nothing
- schedule_timeout() call without setting current state does nothing
- "allow_sleep" parameter is not really used

Refactor the function so that it really tries to wait. In case of timeout try
to recover the bus.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Adding support for i2c controller driver for Broadcom settop
SoCs.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
[wsa: removed superfluous owner in platform_driver]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

When FIFOs are available and enabled, the driver now configures the Atmel
eXtended DMA Controller to perform word accesses instead of byte accesses
when possible.
The actual access width depends on the size of the buffer to transmit.

To enable FIFO support the "atmel,fifo-size" property must be set properly
in the I2C controller node of the device tree.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The probe() function now prints the hardware version of the I2C
controller.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
[wsa: s/version/hw version/] for clarity]
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The alternative command mode was introduced to simplify the transmission
of STOP conditions and to solve timing and latency issues around them.

This mode relies on a new register, the Alternative Command Register,
which must be set at the same time as the Master Mode Register. This new
register was designed to allow simple setup of basic combined transactions
built from up to two unitary transactions.

Indeed, the ACR is split into two areas, which describe one unitary
transaction each. Each area is filled with Data Length 8bit counter, a
Direction and a PEC Request bit. The PEC bit is only used in SMBus mode
and is not supported by this driver yet. Also when using alternative
command mode, the MREAD bit from the Master Mode Register is ignored.
Instead the Direction bits from ACR are used to setup the direction, read
or write, of each unitary transaction. Finally the 8bit counters must
filled with the data length of their respective transaction. Then if only
one transaction is to be used, the data length of the second one must be
set to zero. At the moment, this driver uses only the first transaction.

In addition to MMR and ACR, the Control Register also need to be written
to enable the alternative command mode. That's the purpose of its ACMEN
bit, which stands for Alternative Command Mode Enable.

Note that the alternative command mode is compatible with the use of the
Internal Address Register. So combined transactions for eeprom read are
actually implemented with the Internal Address Register. This register is
written with up to 3 bytes, which are the internal address sent to the
slave through the first write transaction. Then the first area of the ACR
describe the write transaction to follow, which carries the data to be
read from the eeprom. The second area of the ACR is not used so its Data
Length 8bit counter is cleared.

For each byte sent or received by the device, the Data Length 8bit counter
is decremented. When it reaches 0, a STOP condition is automatically sent.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

add a new value "atmel,sama5d2-i2c" for the "compatible" property.
add a new optional property "atmel,fifo-size" to enable FIFO support when
available.
add missing optional properties "dmas" and "dma-names".
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch just fixes typo before applying later patches which will use
register bits with index above 16.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

For TX transactions, the TXCOMP bit in the Status Register is cleared
when the first data is written into the Transmit Holding Register.

In the lines from at91_do_twi_transfer():
at91_twi_write_data_dma(dev);
at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_TXCOMP);

the TXCOMP interrupt may be enabled before the DMA controller has
actually started to write into the THR. In such a case, the TXCOMP bit
is still set into the Status Register so the interrupt is triggered
immediately. The driver understands that a transaction completion has
occurred but this transaction hasn't started yet. Hence the TXCOMP
interrupt is no longer enabled by at91_do_twi_transfer() but instead
by at91_twi_write_data_dma_callback().

Also, the TXCOMP bit in the Status Register in not a clear on read flag
but a snapshot of the transmission state at the time the Status
Register is read.
When a NACK error is dectected by the I2C controller, the TXCOMP, NACK
and TXRDY bits are set together to 1 in the SR. If enabled, the TXCOMP
interrupt is triggered at the same time. Also setting the TXRDY to 1
triggers the DMA controller to write the next data into the THR. Such
a write resets the TXCOMP bit to 0 in the SR. So depending on when the
interrupt handler reads the SR, it may fail to detect the NACK error
if it relies on the TXCOMP bit. The NACK bit and its interrupt should
be used instead.

For RX transactions, the TXCOMP bit in the Status Register is cleared
when the START bit is set into the Control Register. However to unify
the management of the TXCOMP bit when the DMA controller is used, the
TXCOMP interrupt is now enabled by the DMA callbacks for both TX and
RX transfers.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Cc: stable@vger.kernel.org #3.10 and later
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add suspend/resume support to the Broadcom iProc I2C driver
Signed-off-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Commit 1fc2fe20 ("i2c: designware: Add runtime PM hooks") adds
runtime pm support using the same ops for system pm and runtime pm.
When suspend to ram, the i2c host may have been runtime suspended, thus
i2c_dw_disable() hangs.

Previously, I fixed this issue by separating ops for system pm and
runtime pm, then in the system suspend/resume path, runtime pm apis are
used to ensure the device is at correct state.

But as Mika Westerberg pointed out: it sounds a bit silly to resume the
device just because you want to call i2c_dw_disable() for it before
suspending again. He then suggested an elegant solution which keeps the
device runtime suspended during system suspend with the help of
'dev->power.direct_complete'. This patch adopted this solution, and in
fact Mika provided the main code.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Use recovery framework and implement bus recovery using "Bus Monitor" register.
Tests show that shortening SDA to GND results in "completion" timeout with
"BUSY" bit still set, so initiate recovery in this case.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

sizeof(struct i2c_client) is 1088 bytes on a CONFIG_X86_64=y build and
produces following warning when CONFIG_FRAME_WARN is set to 1024:

drivers/i2c/i2c-core.c: In function ‘acpi_i2c_space_handler’:
drivers/i2c/i2c-core.c:367:1: warning: the frame size of 1152 bytes is
larger than 1024 bytes [-Wframe-larger-than=]

This is not critical given that kernel stack is 16 kB on x86_64 but lets
reduce the stack usage by allocating the struct i2c_client from the heap.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add mediatek MT8173 I2C controller driver. Compare to I2C controller
of earlier mediatek SoC, MT8173 fix write-then-read limitation, and
also increase message size to 64kb.
Signed-off-by: Xudong Chen <xudong.chen@mediatek.com>
Signed-off-by: Liguo Zhang <liguo.zhang@mediatek.com>
Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The mediatek SoCs have I2C controller that handle I2C transfer.
This patch include common I2C bus driver.
This driver is compatible with I2C controller on mt65xx/mt81xx.
Signed-off-by: Xudong Chen <xudong.chen@mediatek.com>
Signed-off-by: Liguo Zhang <liguo.zhang@mediatek.com>
Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

int is vague, let's simply use the type of the variable in question.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Inform users what went wrong from the core, so drivers don't have to do
it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

There was some confusion what was needed to utilize the slave support,
so let's be more precise about this. Add an introductory paragraph to
the development section while we are here.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

So users can check in advance if there is slave support.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add SLIMpro I2C device driver on APM X-Gene platform. This I2C
device driver use the SLIMpro Mailbox driver to tunnel message to
the SLIMpro coprocessor to do the work of accessing I2C components.
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Hieu Le <hnle@apm.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

implement bus recovery methods for i2c-omap
so we can recover from situations where SCL/SDA
are stuck low.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The platform_device_id is not modified by these drivers and core uses it
as const.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This adds calls to pinctrl subsystem in order to switch pin states
on suspend/resume if you provide a "sleep" state in DT.

If no "sleep" state is provided in the DT, these calls turn
to NOPs, so we don't need error checking here.
Signed-off-by: Pascal Huerst <pascal.huerst@gmail.com>
Reviewed-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The GPIO subsystem provides dummy GPIO consumer functions if GPIOLIB is
not enabled. Hence drivers that depend on GPIOLIB, but use GPIO consumer
functionality only, can still be compiled if GPIOLIB is not enabled.

Relax the dependency on GPIOLIB if COMPILE_TEST is enabled, where
appropriate.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

info(drivers/i2c/busses/i2c-xiic.c:55): Scanning doc for struct xiic_i2c
Warning(drivers/i2c/busses/i2c-xiic.c:79): No description found for parameter 'endianness'
Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Although unlikely, it is remotely possible for an i2c command to need
more than 200ms complete. Unlike smbus, i2c devices can clock stretch
for an unspecified amount of time. The longest time I've seen
specified for a device is 144ms (bq27541 battery gas), but one could
imagine a device taking a bit slower. 1 second "ought to be enough for
anyone."

The above is not the only justifcation for going above 200ms for a
timeout, though.  It turns out that if you've got a large number of
printks going out to a serial console, interrupts on a CPU can be
disabled for hundreds of milliseconds. That's not a great situation to
be in to start with (maybe we should put a cap in vprintk_emit()) but
it's pretty annoying to start seeing unexplained i2c timeouts.

Note that to understand why we can timeout when printk has interrupts
disabled, you need to understand that on current Linux ARM kernels
interrupts are routed to a single CPU in a multicore system. Thus,
you can get:

1. CPU1 is running rk3x_i2c_xfer()
2. CPU0 calls vprintk_emit(), which disables all IRQs on CPU0.
3. I2C interrupt is ready but is set to only run on CPU0, where IRQs
   are disabled.
4. CPU1 timeout expires. I2C interrupt is still ready, but CPU0 is
   still sitting in the same vprintk_emit()
5. CPU1 sees that no interrupt happened in 200ms, so timeout.

A normal system shouldn't see i2c timeouts anyway, so increasing the
timeout should help people debugging without hurting other people
excessively.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Tested-by: Caesar Wang <wxt@rock-chips.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>