The pen down IRQ will toggle during each X,Y,Z measurement cycle.
Even though the IRQ is disabled it will be latched and delivered
when after enable_irq. Thus in the IRQ handler we must avoid
starting a new measurement cycle when such an "unwanted" IRQ happens.
Add a get_pendown_state platform function, which will probably
determine this by reading the current GPIO level of the pen IRQ pin.

Move the IRQ reenabling from the SPI RX function to the timer. After
the last power down message the pen IRQ pin is still active for a
while and get_pendown_state would report incorrectly a pen down state.

When suspending we should check the ts->pending flag instead of
ts->pendown, since the timer can be pending regardless of ts->pendown.
Also if ts->pending is set we can be sure that the timer is running,
so no need to rearm it. Similarly if ts->pending is not set we can
be sure that the IRQ is enabled (and the timer is not).
Signed-off-by: NImre Deak <imre.deak@nokia.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

- Add disable attribute to support device locking mode where
  unintentional touch event shouldn't wake up the system;
- Update comments;
- Add missing spin_lock_init;
- Do device resume with the lock held;
- Do cleanup calls / free memory in the reverse order of initialization.
Signed-off-by: NImre Deak <imre.deak@nokia.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

Sometimes a polling loop had a hard time changing state without
pre-emption enabled.  Use msleep instead, it's better anyway.
Signed-off-by: NJuha Yrjola <juha.yrjola@nokia.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

Some touchscreens seem to oscillate heavily for a while after touching
the screen.  Implement support for sampling the screen until we get two
consecutive values that are close enough.
Signed-off-by: NImre Deak <imre.deak@nokia.com>
Signed-off-by: NJuha Yrjola <juha.yrjola@nokia.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

Submit a seperate request for powering down the ADC in ads7846,
doing it after the last read request.  Otherwise some of the read
values are incorrect.
Signed-off-by: NImre Deak <imre.deak@nokia.com>
Signed-off-by: NJuha Yrjola <juha.yrjola@nokia.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

It's handy for userspace diagnostics to see the pen down status, to
see whether the touchscreen is "stuck" (shortcircuited).
Signed-off-by: NImre Deak <imre.deak@nokia.com>
Signed-off-by: NJuha Yrjola <juha.yrjola@nokia.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

drivers/input/touchscreen/ads7846.c: In function `ads7846_read12_ser':
drivers/input/touchscreen/ads7846.c:207: warning: implicit declaration of function `disable_irq'
drivers/input/touchscreen/ads7846.c:209: warning: implicit declaration of function `enable_irq'

Cc: Dmitry Torokhov <dtor_core@ameritech.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

sparc32:

drivers/input/touchscreen/ads7846.c: In function `ads7846_read12_ser':
drivers/input/touchscreen/ads7846.c:206: warning: implicit declaration of function `disable_irq'
drivers/input/touchscreen/ads7846.c:208: warning: implicit declaration of function `enable_irq'

Cc: Dmitry Torokhov <dtor_core@ameritech.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This updates the ads7846 touchscreen driver:
  - to allow faster clocking (this driver doesn't push sample rates);
  - bugfixes the conversion of spi_transfer to lists;
  - some dma-unsafe command buffers are fixed.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

There's no need to have request_irq followed by set_irq_type.
Just use request_irq with the appropriate SA_TRIGGER flags.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This makes the SPI core and its users access transfers in the SPI message
structure as linked list not as an array, as discussed on LKML.

From: David Brownell <dbrownell@users.sourceforge.net>

  Updates including doc, bugfixes to the list code, add
  spi_message_add_tail().  Plus, initialize things _before_ grabbing the
  locks in some cases (in case it grows more expensive).  This also merges
  some bitbang updates of mine that didn't yet make it into the mm tree.
Signed-off-by: NVitaly Wool <vwool@ru.mvista.com>
Signed-off-by: NDmitry Pervushin <dpervushin@gmail.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This updates the ads7864 driver to use the new "spi_driver" struct, and
includes some minor unrelated cleanup.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This is a driver for the ADS7846 touchscreen sensor, derived from
the corgi_ts and omap_ts drivers.  Key differences from those two:

  - Uses the new SPI framework (minimalist version)
  - <linux/spi/ads7846.h> abstracts board-specific touchscreen info
  - Sysfs attributes for the temperature and voltage sensors
  - Uses fewer ARM-specific IRQ primitives

The temperature and voltage sensors show up in sysfs like this:

  $ pwd
  /sys/devices/platform/omap-uwire/spi2.0
  $ ls
  bus@          input:event0@ power/        temp1         vbatt
  driver@       modalias      temp0         vaux
  $ cat modalias
  ads7846
  $ cat temp0
  991
  $ cat temp1
  1177
  $

So far only basic testing has been done.  There's a fair amount of hardware
that uses this sensor, and which also runs Linux, which should eventually
be able to use this driver.

One portability note may be of special interest.  It turns out that not all
SPI controllers are happy issuing requests that do things like "write 8 bit
command, read 12 bit response".  Most of them seem happy to handle various
word sizes, so the issue isn't "12 bit response" but rather "different rx
and tx write sizes", despite that being a common MicroWire convention.  So
this version of the driver no longer reads 12 bit native-endian words; it
reads 16-bit big-endian responses, then byteswaps them and shifts the
results to discard the noise.
Signed-off-by: NDavid Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>