This makes the topology clearer. For instance, by adding a pca9547
device with address 0x70 to bus i2c-0, you get:

/sys/class/i2c-dev/i2c-0/device/0-0070/channel-0 -> i2c-1
...
/sys/class/i2c-dev/i2c-0/device/0-0070/channel-7 -> i2c-8
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
[wsa: simplified sysfs-usage and fixed format string usage]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Martin Belanger <martin.belanger@cyaninc.com>
Acked-by: Danielle Costantino <danielle.costantino@gmail.com>

The current implementation creates muxed i2c-<n> busses as immediate
children of their i2c-<n> parent bus. In case of multiple muxes on one
bus, it is impossible to determine which muxed bus comes from which mux.

It could be argued that the parent device should be changed from the
parent adapter to the mux device. This has pros and cons. To improve the
topology, simply add a "mux_device" symlink pointing to the actual
muxing device, so we can distinguish muxed busses. Doing it this way, we
don't break the ABI.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>

No need to initialize 'ret' if it gets assigned directly after that.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Add dma support for i2c. This function depend on DMA driver.
You can turn on it by write both the dmas and dma-name properties in dts node.
DMA is optional, even DMA request unsuccessfully, i2c can also work well.
Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

If the inlcude headers aren't sorted alphabetically, then the
logical choice is to append new ones, however that creates a
lot of potential for conflicts or duplicates because every change
will then add new includes in the same location.
Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Since commit 2fd36c55 ("i2c: core: Map OF IRQ at probe time"),
i2c slaves without interrupts (e.g. da9210 and at24 on r8a7791/koelsch)
fail to probe:

    at24: probe of 2-0050 failed with error -22

    da9210: probe of 6-0068 failed with error -22

This happens because the call to of_irq_get() in i2c_device_probe()
returns -EINVAL.

If a device node does not have an "interrupts" property,
of_irq_parse_one() fails. Unlike irq_of_parse_and_map(), of_irq_get()
does not ignore errors from of_irq_parse_one(), but forwards them.

Make i2c_device_probe() ignore all errors but -EPROBE_DEFER to fix this,
just like platform_get_irq() and platform_get_irq_byname() already do.

Fixes: 2fd36c55 ("i2c: core: Map OF IRQ at probe time")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add support for the IMG I2C Serial Control Bus (SCB) found on the
Pistachio and TZ1090 SoCs.
Reviewed-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
[Ezequiel: code cleaning and rebasing]
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Introduce a devicetree binding for Imagination Technologies
I2C SCB controller.
Reviewed-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The driver tried to access device registers with the (little-endian)
iowrite/ioread functions. While this worked on little-endian machines
(e.g. Microblaze with AXI bus), it made the driver unusable on
big-endian machines (e.g. PPC405 with PLB).

During the probe function, the driver tried to write a 32-bit reset mask
into the reset register. This caused an error interrupt on big-endian
systems, because the device detected an invalid (byte-swapped) reset
mask. The result was an Oops.

The patch implements an endianness detection similar to the one used in
other Xilinx drivers like drivers/spi/spi-xilinx.c. It was tested on a
PPC405/PLB system.
Signed-off-by: Thomas Gessler <Thomas.Gessler@exp2.physik.uni-giessen.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

I have a at24 EEPROM connected via i2c bus provided by ISCH i2c
bus driver. This bus driver does not support
I2C_FUNC_SMBUS_WRITE_I2C_BLOCK and so I was looking for a way
to be able to write the eeprom. This patch adds support for
I2C_SMBUS_BYTE_DATA writing via i2c_smbus_write_byte_data.
It is quite slow, but it works.
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
[wsa: s/use_smbuse_write/use_smbus_write/]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Devin Ryles <devin.ryles@intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

No user needs magic hex values, makes this debug output. Add DMA info.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Make it possible to transfer i2c message buffers via DMA.
Start/Stop/Sending_Slave_Address is still handled using the old state
machine, it is sending the actual data that is done via DMA. This is
least intrusive and allows us to work with the message buffers directly
instead of preparing a custom buffer which involves copying the data
around.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: fixed an uninitialized var problem]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Improves readability and reduces chances of duplicates.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Amend the at91 i2c pin controller to set the state of the pins to:
- "default" on resume.
- "sleep" on suspend().

This should make it possible to optimize energy usage for the pins
both for the suspend/resume cycle
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch enforces correct I2C error returned codes from Freescale's
MPC i2c bus driver, allowing for proper user-space/kernel error
handling.
Signed-off-by: Danielle Costantino <danielle.costantino@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Don't log the host status register value in i801_isr(), it has very
little value and fills up the log when debugging is enabled.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

There is a control bit in the PCI configuration space which disables
interrupts. If this bit is set, the driver should not try to make use
of interrupts, it won't receive any.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The i2c-i801 driver can work without interrupts, so there is no reason
to make a request_irq failure fatal. Instead we can simply fallback
to polling.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Some systems have been reported to have trouble with interrupts. Use
wait_event_timeout() instead of wait_event() so we don't get stuck in
that case, and log the problem.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

As show in I2C specification:
- Standard-mode: the minimum HIGH period of the scl clock is 4.0us
                 the minimum LOW period of the scl clock is 4.7us
- Fast-mode: the minimum HIGH period of the scl clock is 0.6us
             the minimum LOW period of the scl clock is 1.3us

I have measured i2c SCL waveforms in fast-mode by oscilloscope
on rk3288-pinky board. the LOW period of the scl clock is 1.3us.
It is so critical that we must adjust LOW division to increase
the LOW period of the scl clock.

Thanks Doug for the suggestion about division formulas.
Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Max Schwarz <max.schwarz@online.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

When a signal is caught while the i2c-davinci bus driver is
transferring, the driver just "abandons" the transfer and leaves the
controller to fend for itself. The next I2C transaction will find the
controller in an undefined state and often results in a stream of
"initiating i2c bus recovery" messages until the controller arrives in a
defined state. This behaviour also sends out "half" or possibly even
mixed messages to I2C client devices which may put them in an undesired
state as well. So, let's get simply uninterruptible.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Drivers should put the device into low power states proactively whenever the
device is not in use. Thus implement support for runtime PM and use the
autosuspend feature to make sure that we can still perform well in case we see
lots of i2c traffic within short period of time.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

I2C clients instantiated from OF get their IRQ mapped at device
registration time. This leads to the IRQ being silently ignored if the
related irqchip hasn't been proved yet.

Fix this by moving IRQ mapping at probe time using of_get_irq(). The
function operates as irq_of_parse_and_map() but additionally returns
-EPROBE_DEFER if the irqchip isn't available, allowing us to defer I2C
client probing.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The function will be used by the I2C core which can be compiled as a
module.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add support for r8a73a4 (R-Mobile APE6) and sh73a0 (SH-Mobile AG5).
On these SoCs, the operating clock runs faster that on previous SoCs,
and the internal SCL clock counter gets incremented every 2 clocks of
the operating clock, just like on R-Car Gen2.

Cfr. the "/2" in the calculation of ICCL/ICCH in section "I2C Bus
Interface (IIC)", subsection "Transfer Rate" of the datasheets.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Explicitly list the various SoC-specific compatible properties.
This allows checkpatch to validate DTSes.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

According to Documentation/CodingStyle - Chapter 14:

"The preferred form for passing a size of a struct is the following:

	p = kmalloc(sizeof(*p), ...);

The alternative form where struct name is spelled out hurts readability and
introduces an opportunity for a bug when the pointer variable type is changed
but the corresponding sizeof that is passed to a memory allocator is not."

So do it as recommeded.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Pull arm64 fixes from Catalin Marinas:
 - enable bpf syscall for compat
 - cpu_suspend fix when checking the idle state type
 - defconfig update

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: defconfig: update defconfig for 3.18
  arm64: compat: Enable bpf syscall
  arm64: psci: fix cpu_suspend to check idle state type for index

Pull ARM SoC fixes from Olof Johansson:
 "Another quiet week:

   - a fix to silence edma probe error on non-supported platforms from
     Arnd
   - a fix to enable the PL clock for Parallella, to make mainline
     usable with the SDK.
   - a somewhat verbose fix for the PLL clock tree on VF610
   - enabling of SD/MMC on one of the VF610-based boards (for testing)
   - a fix for i.MX where CONFIG_SPI used to be implicitly enabled and
     now needs to be added to the defconfig instead
   - another maintainer added for bcm2835: Lee Jones"

* tag 'armsoc-for-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: dts: zynq: Enable PL clocks for Parallella
  dma: edma: move device registration to platform code
  ARM: dts: vf610: add SD node to cosmic dts
  MAINTAINERS: update bcm2835 entry
  ARM: imx: Fix the removal of CONFIG_SPI option
  ARM: imx: clk-vf610: define PLL's clock tree

Pull devicetree bugfix from Grant Likely:
 "One buffer overflow bug that shouldn't be left around"

* 'devicetree/merge' of git://git.kernel.org/pub/scm/linux/kernel/git/glikely/linux:
  of: Fix overflow bug in string property parsing functions

Pull btrfs fix from Chris Mason:
 "It's a one liner for an error cleanup path that leads to crashes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix kfree on list_head in btrfs_lookup_csums_range error cleanup

Merge tag 'driver-core-3.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are 3 tiny fixes for 3.18-rc4.

  One fixes up a long-stading race condition in the driver core for
  removing directories in /sys/devices/virtual/ and the other 2 fix up
  the wording of a new Kconfig option that was added in 3.18-rc1"

* tag 'driver-core-3.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  tiny: rename ENABLE_DEV_COREDUMP to ALLOW_DEV_COREDUMP
  tiny: reverse logic for DISABLE_DEV_COREDUMP
  sysfs: driver core: Fix glue dir race condition by gdp_mutex

Pull staging driver fixes from Greg KH:
 "Here are some staging/iio fixes for 3.18-rc4.

  Nothing major, just a few bugfixes of things that have been reported"

* tag 'staging-3.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging:iio:ade7758: Remove "raw" from channel name
  staging:iio:ade7758: Fix check if channels are enabled in prenable
  staging:iio:ade7758: Fix NULL pointer deref when enabling buffer
  iio: as3935: allocate correct iio_device size
  io: accel: kxcjk-1013: Fix iio_event_spec direction
  iio: tsl4531: Fix compiler error when CONFIG_PM_OPS is not defined
  iio: adc: mxs-lradc: Disable the clock on probe failure
  iio: st_sensors: Fix buffer copy
  staging:iio:ad5933: Drop "raw" from channel names
  staging:iio:ad5933: Fix NULL pointer deref when enabling buffer

Pull tty/serial fixes from Greg KH:
 "Here are some tiny serial/tty fixes for 3.18-rc4 that resolve some
  reported issues"

* tag 'tty-3.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: Fix pty master poll() after slave closes v2
  serial: of-serial: fix uninitialized kmalloc variable
  tty/vt: don't set font mappings on vc not supporting this
  tty: serial: 8250_mtk: Fix quot calculation
  tty: Prevent "read/write wait queue active!" log flooding
  tty: Fix high cpu load if tty is unreleaseable
  serial: Fix divide-by-zero fault in uart_get_divisor()

Pull USB fixes from Greg KH:
 "Here are some USB fixes for 3.18-rc4.

  Just a bunch of little fixes resolving reported issues and new device
  ids for existing drivers.  Full details are in the shortlog"

* tag 'usb-3.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (26 commits)
  USB: Update default usb-storage delay_use value in kernel-parameters.txt
  USB: cdc-acm: add quirk for control-line state requests
  phy: omap-usb2: Enable runtime PM of omap-usb2 phy properly
  USB: storage: Fix timeout in usb_stor_euscsi_init() and usb_stor_huawei_e220_init()
  USB: cdc-acm: only raise DTR on transitions from B0
  Revert "storage: Replace magic number with define in usb_stor_euscsi_init()"
  usb: core: notify disconnection when core detects disconnect
  usb: core: need to call usb_phy_notify_connect after device setup
  uas: Add US_FL_NO_ATA_1X quirk for 2 more Seagate models
  xhci: no switching back on non-ULT Haswell
  USB: quirks: enable device-qualifier quirk for yet another Elan touchscreen
  USB: quirks: enable device-qualifier quirk for another Elan touchscreen
  MAINTAINERS: Remove duplicate entry for usbip driver
  usb: storage: fix build warnings !CONFIG_PM
  usb: Remove references to non-existent PLAT_S5P symbol
  uas: Add NO_ATA_1X for VIA VL711 devices
  xhci: Disable streams on Asmedia 1042 xhci controllers
  USB: HWA: fix a warning message
  uas: Add US_FL_NO_ATA_1X quirk for 1 more Seagate model
  usb-storage: handle a skipped data phase
  ...

The Parallella board comes with a U-Boot bootloader that loads one of
two predefined FPGA bitstreams before booting the kernel. Both define an
AXI interface to the on-board Epiphany processor.

Enable clocks FCLK0..FCLK3 for the Programmable Logic by default.

Otherwise accessing, e.g., the ESYSRESET register freezes the board,
as seen with the Epiphany SDK tools e-reset and e-hw-rev, using /dev/mem.

Cc: <stable@vger.kernel.org> # 3.17.x
Signed-off-by: Andreas Färber <afaerber@suse.de>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Olof Johansson <olof@lixom.net>