In a multimaster environment, after IP software reset, BB-bit value doesn't
correspond to the current bus state. It may happen what BB-bit will be 0,
while the bus is busy due to another I2C master activity.

Any transfer started when BB=0 and bus is busy wouldn't be completed by IP
and results in controller timeout. More over, in some cases IP could
interrupt another master's transfer and corrupt data on wire.

The commit implement method allowing to prevent IP from entering into
"controller timeout" state and from "data corruption" state.

The one drawback is the need to wait for 10ms before the first transfer.

Tested on Beagleboard XM C.
Tested on BBB and AM437x Starter Kit by Felipe Balbi.
Signed-off-by: NAlexander Kochetkov <al.kochet@gmail.com>
Tested-by: NFelipe Balbi <balbi@ti.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Delete STAT_AD0 mask as unrelated to current IP (omap1?).
Delete DEBUG conditional around SYSTEST masks group.
Add SYSTEST functional mode masks for SCL and SDA.
Add STAT_BF mask.
Signed-off-by: NAlexander Kochetkov <al.kochet@gmail.com>
Tested-by: NFelipe Balbi <balbi@ti.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The i2c input clock can change dynamically, e.g. on the RK3066 where
pclk_i2c0 and pclk_i2c1 are connected to the armclk, which changes
rate on cpu frequency scaling.

Until now, we incorrectly called clk_get_rate() while holding the
i2c->lock in rk3x_i2c_xfer() to adapt to clock rate changes.
Thanks to Huang Tao for reporting this issue.

Do it properly now using the clk notifier framework. The callback
logic was taken from i2c-cadence.c.

Also rename all misleading "i2c_rate" variables to "clk_rate", as they
describe the *input* clk rate.
Signed-off-by: NMax Schwarz <max.schwarz@online.de>
Tested-by: Doug Anderson <dianders@chromium.org> on RK3288
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

If dma controller is not probed, defer i2c probe.
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Since at91sam9g45 is now DT-only, all DMA capable users of this driver
are using the DT case, and the legacy support can be removed.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This allows checkpatch to validate more DTSes.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This allows checkpatch to validate more DTSes.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

It should be the DMA device, not the platform device.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NYao Yuan <yao.yuan@freescale.com>

The SCB is present on IMG SoCs other than the META-based TZ1090,
such as the MIPS-based Pistachio SoC.  Relax the Kconfig dependency
so that it can be built on any MIPS or META machine.
Signed-off-by: NAndrew Bresticker <abrestic@chromium.org>
Acked-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This is a driver for the I2C controller found in Amlogic Meson SoCs.
Signed-off-by: NBeniamino Galvani <b.galvani@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

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: NGerlando Falauto <gerlando.falauto@keymile.com>
[wsa: simplified sysfs-usage and fixed format string usage]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NMartin Belanger <martin.belanger@cyaninc.com>
Acked-by: NDanielle 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: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NGuenter Roeck <linux@roeck-us.net>

No need to initialize 'ret' if it gets assigned directly after that.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NMika 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: NYuan Yao <yao.yuan@freescale.com>
Signed-off-by: NWolfram 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: NYuan Yao <yao.yuan@freescale.com>
Signed-off-by: NWolfram 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: NGeert Uytterhoeven <geert+renesas@glider.be>
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

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

Introduce a devicetree binding for Imagination Technologies
I2C SCB controller.
Reviewed-by: NAndrew Bresticker <abrestic@chromium.org>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@imgtec.com>
Signed-off-by: NWolfram 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: NThomas Gessler <Thomas.Gessler@exp2.physik.uni-giessen.de>
Signed-off-by: NWolfram 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: NChristian Gmeiner <christian.gmeiner@gmail.com>
[wsa: s/use_smbuse_write/use_smbus_write/]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Signed-off-by: NDevin Ryles <devin.ryles@intel.com>
Reviewed-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

No user needs magic hex values, makes this debug output. Add DMA info.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram 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: NWolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: fixed an uninitialized var problem]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Improves readability and reduces chances of duplicates.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram 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: NWenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: NWolfram 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: NDanielle Costantino <danielle.costantino@gmail.com>
Signed-off-by: NWolfram 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: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NWolfram 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: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NWolfram 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: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NWolfram 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: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NWolfram 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: NAddy Ke <addy.ke@rock-chips.com>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NMax Schwarz <max.schwarz@online.de>
Signed-off-by: NWolfram 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: NMike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Signed-off-by: NWenyou Yang <wenyou.yang@atmel.com>
Acked-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NWolfram 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: NWenyou Yang <wenyou.yang@atmel.com>
Acked-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Signed-off-by: NWolfram 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: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The function will be used by the I2C core which can be compiled as a
module.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: NRob Herring <robh@kernel.org>
Acked-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NWolfram 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: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

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