Add support for the PIO mode and mixed PIO/DMA mode support. The mixed
PIO/DMA is the default mode of operation. This shall leverage overhead
that the driver creates due to setting up DMA descriptors even for very
short transfers.

The current boundary between PIO/DMA 8 bytes, transfers shorter than 8
bytes are transfered by PIO, longer transfers use DMA. The performance
of write transfers remains unchanged, while there is a minor improvement
of read performance. Reading 16KB EEPROM with DMA-only operations gives
a read speed of 39.5KB/s, while with then new mixed-mode the speed is
blazing 40.6KB/s.
Signed-off-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

err_cpufreq label is now used only once. It can be removed and related
code can be moved to the caller location.
Signed-off-by: NTushar Behera <tushar.behera@linaro.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

In i2c-s3c2410 driver probe, only s3c24xx_i2c_init() needs the I2C clock
to be enabled. Moving clk_prepare_enable() and clk_disable_unprepare()
calls to around this function simplifies the return path of probe call.
Signed-off-by: NTushar Behera <tushar.behera@linaro.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

i2c-s3c2410 driver is modified to use devm_clk_get()
and devm_request_irq(). This also simplifies the
return path in driver's probe.
Signed-off-by: NTushar Behera <tushar.behera@linaro.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

err_noclk label redirects to a simple return statement. Move the
return statement to the caller location and remove the label.
Signed-off-by: NTushar Behera <tushar.behera@linaro.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

cppcheck rightfully reports those as "reassigned a value before the old
one has been used."
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Cc: Linus Walleij <linus.walleij@stericsson.com>

Amend the I2C nomadik pin controller to optionally take a pin control
handle and set the state of the pins to:

- "default" on boot, resume and before performing an i2c transfer
- "idle" after initial default, after resume default, and after each
   i2c xfer
- "sleep" on suspend()

This should make it possible to optimize energy usage for the pins
both for the suspend/resume cycle, and for runtime cases inbetween
I2C transfers.
Signed-off-by: NPatrice Chotard <patrice.chotard@stericsson.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
[wsa: fixed braces on one else-branch]
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Signed-off-by: NJoachim Eastwood <manabian@gmail.com>
Acked-by: NLudovic Ddesroches <ludovic.desroches@atmel.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

NVIDIA's Tegra114 has following enhanced feature in i2c controller:
- Enable/disable control for per packet transfer complete interrupt.
  Earlier SoCs could not disable this.
- Single clock source for standard/fast and HS mode clock speed.
  The clock divisor for fast/standard mode is added into the i2c
  controller to meet the HS and standard/fast mode of clock speed
  from single source.

Add support for the above feature to make it functional on T114 SOCs.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Intel Lynxpoint has two I2C controllers. These controllers are enumerated
from ACPI namespace with IDs INT33C2 and INT33C3. Add support for these to
the I2C DesignWare platform driver.

This is based on the work of Dirk Brandewie.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

In order to save power the device should be put to low power states
whenever it is not being used. We implement this by enabling minimal
runtime PM support.

There isn't much to do for the device itself as it is disabled once the
last transfer is completed but subsystem/domain runtime PM hooks can save
more power by power gating the device etc.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

If IC_EMPTYFIFO_HOLD_MASTER_EN is set to one, the DesignWare I2C controller
doesn't generate STOP on the bus when the FIFO is empty. This violates the
rules of Linux I2C stack as it requires that the STOP is issued once the
i2c_transfer() is finished.

However, there is no way to detect this from the hardware registers, so we
must make sure that the STOP bit is always set once the last byte of the
last message is transferred.

This patch is based on the work of Dirk Brandewie.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

avoid these checkpatch.pl issues :
- ERROR: "foo * bar" should be "foo *bar"
- ERROR: switch and case should be at the same indent
- ERROR: "(foo*)" should be "(foo *)"
- ERROR: do not use assignment in if condition
- ERROR: space required before the open parenthesis '('
- WARNING: suspect code indent for conditional statements
- WARNING: quoted string split across lines
- WARNING: space prohibited between function name and open parenthesis '('
- WARNING: line over 80 characters
also add spaces around some "+", "=", "*"
Signed-off-by: NLaurent Navet <laurent.navet@gmail.com>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The driver can also be built as a module so add MODULE_LICENSE for it. In
addition add MODULE_DESCRIPTION as well.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Commit 0bdfe0cb (i2c: omap: sanitize
exit path) changed the interrupt handler to exit early and complete
the transfer after the draining IRQ is handled. As a result, the ARDY
may not be cleared properly, and it may cause all future I2C transfers
to timeout with "timeout waiting for bus ready". This is reproducible
at least with N900 when twl4030_gpio makes a long write (> FIFO size)
during the probe (http://marc.info/?l=linux-omap&m=135818882610432&w=2).

The fix is to continue until we get ARDY interrupt that completes the
transfer. Tested with 3.8-rc4 + N900: 20 boots in a row without errors;
without the patch the problem triggers after few reboots.
Signed-off-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The errata handling function acks wrong interrupt in case of "Arbitration
lost". Fix it.

Discovered during code review, the real impact of the bug is unknown.
Signed-off-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

in probe() entry of i2c_driver, set the of node of adapter and
call of_i2c_register_devices to register all i2c_client from
dt child-nodes
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

cmd_err is used to handle error code, so it should not be unsigned.

This fixes the following warning when building with W=1 option:

drivers/i2c/busses/i2c-mxs.c: In function 'mxs_i2c_xfer_msg':
drivers/i2c/busses/i2c-mxs.c:331:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Acked-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Cc: stable@kernel.org

The init_completion() call does reinit not only the variable carrying
the flag that the completion finished, but also initialized the
waitqueue associated with the completion. On the contrary, the
INIT_COMPLETION() call only reinits the flag.

In case there was anything still stuck in the waitqueue, subsequent call
to init_completion() would be able to create possible race condition. This
patch uses the proper function and moves init_completion() into .probe() call
of the driver, to be issued only once.

Note that such scenario is impossible, since two threads can never enter the
mxs_i2c_xfer_msg(), since whole this section is protected by mutex in I2C core.
This by no means allows this issue to exit though.
Signed-off-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

CONFIG_HOTPLUG is going away as an option.  As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> (for ocores and mux-gpio)
Acked-by: Havard Skinnemoen <hskinnemoen@gmail.com> (for i2c-gpio)
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> (for puf3)
Acked-by: Barry Song <baohua.song@csr.com> (for sirf)
Reviewed-by: NJean Delvare <khali@linux-fr.org>
[wsa: Fixed "foo* bar" flaws while we are here]
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

dev_<level> calls take less code than dev_printk(KERN_<LEVEL>
and reducing object size is good.
Coalesce formats for easier grep.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

I did not receive a single bug report after interrupt support was
added for a limited number of chips. So I'd say the code is good and
should be enabled for all supported chips, that is: ICH5 and later.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Reviewed-by: NDaniel Kurtz <djkurtz@chromium.org>

Add support for probing slave devices parsed from the device tree.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The OMAP_I2C_FLAG_RESET_REGS_POSTIDLE is not used anymore
in the i2c driver. Remove the flag.
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Add dma support for Atmel TWI which is available on sam9x5 and later.

When using dma for reception, you have to read only n-2 bytes. The last
two bytes are read manually. Don't doing this should cause to send the
STOP command too late and then to get extra data in the receive
register.
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Replace tabs for struct members indentation by space to minimise line changes
when adding new members which would require extra tabs to keep alignment.
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

This patch fixes the following warning:
drivers/i2c/busses/i2c-at91.c: In function ‘at91_twi_get_driver_data’:
drivers/i2c/busses/i2c-at91.c:411:3: warning: return discards ‘const’ qualifier from pointer target type [enabled by default]
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Properly terminate the DMA transfer in case the DMA PIO transfer
or setup fails for any reason.
Signed-off-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

There is no reason to disable the I2C SMBus quick mode on this
IP block. Enable it. This essentially fixes the problem with the
"i2c-detect" command for probing the bus.
Signed-off-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Properly terminate the DMA transfer in case the DMA PIO transfer
or setup fails for any reason.
Signed-off-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The changes in "i2c-s3c2410: use exponential back off while polling for
bus idle" remove the initial busy wait for I2C transfers to complete and
replace it with usleep_range() calls which will schedule.

Since for older SoCs I2C transfers would usually complete within an
extremely small number of CPU cycles there is a win from not having to
schedule.  This happens because on the older SoCs the cores run at a
smaller multiple of the speeds that the I2C bus is operating at; on more
modern SoCs the busy wait is less likely to be effective.

Fix the issue by restoring the busy wait, reducing the number of spins
from 20 to 3 which covers the overwhelming majority of I2C transfers on
the SoCs where the busy wait is effective.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NOlof Johansson <olof@lixom.net>
Reviewed-by: NDaniel Kurtz <djkurtz@chromium.org>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

This moves the grlib set and get functions into the #ifdef CONFIG_OF block to
avoid warnings of unimplemented functions when compiling with -Wunused-function
when CONFIG_OF is not defined.
Signed-off-by: NAndreas Larsson <andreas@gaisler.com>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

This adds the mfd cell to use the i2c part of the Nano River Technologies
viperboard as i2c master.
Signed-off-by: NLars Poeschel <poeschel@lemonage.de>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

"Whether" is misspelled in various comments across the tree; this
fixes them. No code changes.
Signed-off-by: NAdam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Store the requested gpios so that they can be freed on error/removal.
Signed-off-by: NAbhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The I2C driver makes a gpio_request during initialization. This request
happens again on resume and fails due to the earlier successful request.
Re-factor the code to only initialize the gpios during probe.

Errors on resume without this:
[   16.020000] s3c-i2c s3c2440-i2c.0: gpio [42] request failed
[   16.020000] s3c-i2c s3c2440-i2c.1: gpio [44] request failed
[   16.020000] s3c-i2c s3c2440-i2c.2: gpio [6] request failed
Signed-off-by: NAbhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Store the requested gpios so that they can be freed on error/removal.
Signed-off-by: NAbhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Add i2c driver to enable access to devices behind CBUS on Nokia Internet
Tablets.

The patch also adds CBUS I2C configuration for N8x0 which is one of the
users of this driver.
Acked-by: NFelipe Balbi <balbi@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

i2c: ocores: Add support for the GRLIB port of the controller and use function pointers for getreg and setreg functions

The registers in the GRLIB port of the controller are 32-bit and in big endian
byte order. The PRELOW and PREHIGH registers are merged into one register. The
subsequent registers have their offset decreased accordingly. Hence the register
access needs to be handled in a non-standard manner using custom getreg and
setreg functions.

Add setreg and getreg functions for different register widths and let oc_setreg
and oc_getreg use function pointers to call the appropriate functions.

A type is added as the data of the of match table entries. A new entry with a
different compatible string is added to the table. The type of that entry
triggers usage of the custom grlib functions by setting the setreg and getreg
function pointers.
Signed-off-by: NAndreas Larsson <andreas@gaisler.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Add sparc support by using platform_get_irq instead of platform_get_resource.
There are no platform resources of type IORESOURCE_IRQ for sparc, but
platform_get_irq works for sparc. In the non-sparc case platform_get_irq
internally uses platform_get_resource.
Signed-off-by: NAndreas Larsson <andreas@gaisler.com>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>