This code is repeated in probe:
i2c_dev->adapter.algo = &tegra_i2c_algo;

Cc: Donglin Peng <pengdonglin137@163.com>
Signed-off-by: NBarry Song <21cnbao@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

According to "KeyStone Architecture Inter-IC Control Bus User Guide", fixed
additive part of frequency divisors (referred as "d" in the code and datasheet)
always equals to 6, independent of module clock prescaler.

                         module clock frequency
master clock frequency = ----------------------
                         (ICCL + 6) + (ICCH + 6)

It was not the case with original Davinci IP. Introduce new compatible property
"ti,keystone-i2c", which triggers special handling in the driver.

Without this change Keystone-based systems (having 204.8MHz input clock) choose
prescaler 29 (PSC=28). Using d=5 in this case leads to bus bitrate ~353kHz
instead of requested 400kHz. After correction, assuming d=6 bus rate is ~392kHz.
This gives ~11% transfer rate increase.
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Reviewed-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NHemanth Guruva Reddy <hemanth.guruva_reddy@nokia.com>
Tested-by: NLukasz Gemborowski <lukasz.gemborowski@nokia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Issue the warning in all error paths when unable to register MSI or its
handler.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Propagate actual return code when requesting interrupt fails.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

struct pci_dev already has a flag to track if MSI is enabled or not. Use it
directly.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There is no need to repeat the work that is already done in the PCI driver
core. Remove suspend and resume callbacks.

Note that there is no more calls performed to enable or disable a PCI
device during suspend-resume cycle. Nowadays they seems to be
superfluous. Someone can read more in [1].

[1] https://www.kernel.org/doc/ols/2009/ols2009-pages-319-330.pdfSigned-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

pcim_release() will release any requested region. There is no need to duplicate
this effort in the driver.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This fixes the code to suppress sparse warnings like:

drivers/i2c/busses/i2c-ismt.c:725:36: warning: incorrect type in argument 2 (different address spaces)
drivers/i2c/busses/i2c-ismt.c:725:36:    expected void volatile [noderef] <asn:2>*addr
drivers/i2c/busses/i2c-ismt.c:725:36:    got void *
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There is some code duplication in i2c-designware-platdrv and
i2c-designware-pcidrv probe functions. What is even worse that duplication
requires i2c_dw_xfer(), i2c_dw_func() and i2c_dw_isr() i2c-designware-core
functions to be exported.

Therefore move common code into new i2c_dw_probe() and make functions above
local to i2c-designware-core.

While merging the code patch does following functional changes:

- I2C Adapter name will be "Synopsys DesignWare I2C adapter". Previously it
  was used for platform and ACPI devices but PCI device used
  "i2c-designware-pci".
- Using device name for interrupt name. Previous it was platform device name,
  ACPI device name or "i2c-designware-pci".
- Error code from devm_request_irq() and i2c_add_numbered_adapter() will be
  printed in case of error.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Make it easier to distinguish between i2c-designware-platdrv and
i2c-designware-core functions and to be consistent with
i2c-designware-pcidrv.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

dw_readl() and dw_writel() are not used outside of i2c-designware-core and
they are not exported so make them static and remove their forward
declaration.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

i2c_dw_is_enabled() became unused by the commit be58eda7
("i2c: designware-pci: Cleanup driver power management") and
i2c_dw_enable() by the commit 3a48d1c0 ("i2c: prevent spurious
interrupt on Designware controllers").
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Device must not generate interrupts before registering the interrupt
handler so move i2c_dw_disable_int() before requesting it.

There are no known issues with this. The code has been here since commit
fe20ff5c ("i2c-designware: Add support for Designware core behind PCI
devices.").
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There is no need to clear interrupts in i2c_dw_pci_probe() since only place
where interrupts are unmasked is i2c_dw_xfer_init() and there interrupts
are always cleared after commit 2a2d95e9 ("i2c: designware: always
clear interrupts before enabling them").

This allows to cleanup the code and replace i2c_dw_clear_int() in
i2c_dw_xfer_init() by direct register read as there are no other callers.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The requested bit rate can be outside the range supported by the driver.
The maximum bit rate this driver supports at the moment is 400Khz.

If the requested bit rate is larger than the maximum supported by the
driver, set the bitrate to the maximum supported before bitrate_khz is
calculated.

Maximum speed supported by the driver can be increased to 1Mhz by
adding support for "fast plus mode" in the future.

Fixes: commit 27bce457 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver")
Signed-off-by: NSifan Naeem <sifan.naeem@imgtec.com>
Acked-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NJames Hartley <james.hartley@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Clear line status and all generated interrupts from the interrupt
status register before starting a transfer, as we may have
unserviced interrupts from previous transfers that might be
handled in the context of the new transfer.

Fixes: commit 27bce457 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver")
Signed-off-by: NSifan Naeem <sifan.naeem@imgtec.com>
Acked-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NJames Hartley <james.hartley@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

i2c->line_status accumulates the line status bits that have been seen
with each interrupt. As we're only interested in that bit from the
current interrupt, refer to line_status (the argument to img_i2c_auto)
instead of i2c->line_status.
Signed-off-by: NSifan Naeem <sifan.naeem@imgtec.com>
Reviewed-by: NJames Hartley <james.hartley@imgtec.com>
Acked-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Currently, after determining the minimum value for the High period
(TCKH) the remainder of the internal clock pulses is set as the Low
period (TCKL). This causes the i2c clock duty cycle to be much less
than 50%.

Modify the starting position to TCKH and TCKL at 50% of the internal
clock, and adjusts the TCKH and TCKL values from there should the
minimum value for TCKL not be met. This results in duty cycles closer
to 50%.

Fixes: commit 27bce457 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver")
Signed-off-by: NSifan Naeem <sifan.naeem@imgtec.com>
Acked-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NJames Hartley <james.hartley@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Using % can be slow depending on the architecture.

Using DIV_ROUND_UP is nicer and more efficient way to do it.

Fixes: commit 27bce457 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver")
Signed-off-by: NSifan Naeem <sifan.naeem@imgtec.com>
Acked-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NJames Hartley <james.hartley@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Move scb_wr_rd_fence to before reading from fifo and writing to
fifo to make sure the the first read/write is done after the required
number of cycles.

Fixes: commit 27bce457 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver")
Signed-off-by: NSifan Naeem <sifan.naeem@imgtec.com>
Acked-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NJames Hartley <james.hartley@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The code to read from the master read fifo, and write to the master
write fifo, checks a bit in an SCB register before every byte to
ensure that the fifo is not full (write fifo) or empty (read fifo).
Due to clock domain crossing inside the SCB block the updated value
of this bit is only visible after 2 cycles.

The scb_wr_rd_fence() function does 2 dummy writes (to the read-only
revision register), and it's called before reading from or writing to the
fifos to ensure that subsequent reads of the fifo status bits do not read
stale values.

As the 2 dummy writes are required in all versions of the ip, the version
check is dropped.

Fixes: commit 27bce457 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver")
Signed-off-by: NSifan Naeem <sifan.naeem@imgtec.com>
Acked-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NJames Hartley <james.hartley@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Update the comments to match current behaviour. Shorten some comments.
Update copyrights.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

If we don't clear START generation as soon as possible, it may cause
another message to be generated. To keep the race window as small as
possible, we clear it right at the beginning of the interrupt. We don't
need checking since we always want to stop START and STOP generation on
the next occasion after we started it.

This patch improves the situation but sadly does not completely fix it.
It is still to be researched if we can do better given this HW design.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Due to broken HW design, master IRQs are more timing critical, so give
them precedence over slave IRQ.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The manual says (55.4.8.6) that HW does automatically send STOP after
NACK was received. My measuerments confirm that.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Setting up new messages was done in process context while handling a
message was in interrupt context. Because of the HW design, this IP core
is sensitive to timing, so the context switches were too expensive. Move
this setup to interrupt context as well.

In my test setup, this fixed the occasional 'data byte sent twice' issue
which a number of people have seen. It also fixes to send REP_START
after a read message which was wrongly send as a STOP + START sequence
before.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

We want to reuse this function later.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

We make sure to reinit the HW in the timeout case; then we know that
interrupts are always disabled in the sections protected by the
spinlock. Thus, we can simply remove it which is a preparation for
further refactoring. While here, rename the timeout variable to
time_left which is way more readable.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

We don't need to init HW before every transfer since we know the HW
state then. HW init at probe time is enough. While here, add setting the
clock register which belongs to init HW. Also, set MDBS bit since not
setting it is prohibited according to the manual.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The dma_mapping_error() function returns true if there is an error, it
doesn't return an error code.  We should return -ENOMEM.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

The ChromeOS EC tunnel I2C bus driver depend on CROS_EC_PROTO but
MFD_CROS_EC select CROS_EC_PROTO instead. Mixing select and depends
on is bad practice as it may lead to circular Kconfig dependencies.

Since the platform device that is matched with the I2C bus driver
is registered by the ChromeOS EC mfd driver, I2C_CROS_EC_TUNNEL
really depends on MFD_CROS_EC. And because this config option
selects CROS_EC_PROTO, that dependency is met as well. So make the
driver to depend on MFD_CROS_EC instead of CROS_EC_PROTO.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Add support for the I2C controller found on several NXP devices
including LPC2xxx, LPC178x/7x and LPC18xx/43xx. The controller
is implemented as a state machine and the driver act upon the
state changes when the bus is accessed.

The I2C controller supports master/slave operation, bus
arbitration, programmable clock rate, and speeds up to 1 Mbit/s.
Signed-off-by: NJoachim Eastwood <manabian@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

When occur i2c ack error, i2c controller generate two interrupts,
first is the ack error interrupt, then the complete interrupt.
i2c interrupt handler should keep the two interrupt value, and only
call complete() for the complete interrupt.
Signed-off-by: NLiguo Zhang <liguo.zhang@mediatek.com>
Signed-off-by: NEddie Huang <eddie.huang@mediatek.com>
Reviewed-by: NDaniel Kurtz <djkurtz@chromium.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Reset DMA in hardware init function to avoid unknown hardware state
before do any I2C operation.
Signed-off-by: NLiguo Zhang <liguo.zhang@mediatek.com>
Signed-off-by: NEddie Huang <eddie.huang@mediatek.com>
Reviewed-by: NDaniel Kurtz <djkurtz@chromium.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Starting from Intel Sunrisepoint (Skylake PCH) the iTCO watchdog resources
have been moved to reside under the i801 SMBus host controller whereas
previously they were under the LPC device.

In order to support the iTCO watchdog on newer PCHs we need to create the
platform device here in the SMBus driver and pass all known resources using
platform data.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Minor clean up of indenting, no functional change
Signed-off-by: NColin Ian King <colin.king@canonical.com>
[wsa: squashed two lines into one]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The owner of the adapter is missing, while this driver is tristate.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Printing adapter name is irrelevant from this debug print and makes output
needlessly long. Having already device and functions names printed here is
enough for debugging.

While at it remove extra space from "enabled= 0x" and use "%#x" for
printing "0x" prefixed hexadecimal values.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
[wsa: made it a oneliner]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The mentioned flag fixes a warning on Intel Edison board since one of the I2C
controller shares IRQ line with watchdog timer.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>