Add include guard to include/linux/platform_data/sht15.h to prevent
multiple inclusion.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

This patch moves the sht15.h header from include/linux to
include/linux/platform_data, and update existing support (stargate2
platform) accordingly.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

The sht15 sensor allows validating exchanges to and from the device
using a crc8 function. An utility function to reverse a byte has also
been added.
Signed-off-by: NJerome Oufella <jerome.oufella@savoirfairelinux.com>
Acked-by: NJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>

* Add support for:
  - Heater.
  - End of battery notice.
  - Ability not to reload from OTP.
  - Low resolution (12bit temp, 8bit humidity).
* Add an utility function to read individual bytes from the device.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: NJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>

* Add a documentation file for the device.
* Respect a bit more the kernel-doc syntax.
* Rename some variables for clarity.
* Use bool type for flags.
* Use an enum for states (actions being done).
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: NJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>

Data sheet at:
http://www.sensirion.ch/en/pdf/product_information/Datasheet-humidity-sensor-SHT1x.pdf

These sensors communicate over a 2 wire bus running a device specific
protocol.  The complexity of the driver is mainly due to handling the
substantial delays between requesting a reading and the device pulling the
data line low to indicate that the data is available.  This is handled by
an interrupt that is disabled under all other conditions.

I wasn't terribly clear on the best way to handle this, so comments on
that aspect would be particularly welcome!

Interpretation of the temperature depends on knowing the supply voltage.
If configured in a board config as a regulator consumer this is obtained
from the regulator subsystem.  If not it should be provided in the
platform data.

I've placed this driver in the hwmon subsystem as it is definitely a
device that may be used for hardware monitoring and with it's relatively
slow response times (up to 120 millisecs to get a reading) a caching
strategy certainly seems to make sense!
Signed-off-by: NJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>