Move the last remaining driver from i2c/chips to misc. Good ridance!
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Acked-by: NJonathan Cameron <jic23@cam.ac.uk>

According to the TAOS Application Note 'Controlling a Backlight with
the TSL2550 Ambient Light Sensor' (page 14), the actual lux value in
extended mode should be obtained multiplying the calculated lux value
by 5.
Signed-off-by: NMichele Jr De Candia <michele.decandia@valueteam.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Make the I/O faster, mainly by using combined SMBus transactions when
possible. While the TSL2550 datasheet doesn't say the device supports
them, they seem to work just fine in practice, and a combined
transaction is faster than two simple transactions in many cases and
always more reliable.

A side effect is to suppress the delays between SMBus writes and
reads. The datasheet doesn't say they are needed and things work just
fine for me without them.

I also couldn't see any reason for the delay between reading the two
channels. Nor for the loop to get a reading in the first place. The
400 ms delay between samples only matters at chip power-up, after that
the chip always hold the previously sampled value so we never get to
wait.

All these changes make reading the lux value much faster and cheaper.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Tested-by: NMichele De Candia <michele.decandia@valueteam.com>
Cc: Rodolfo Giometti <giometti@linux.it>

I've tested TSL2550 driver and I've found a bug: when light is off, 
returned value from tsl2550_calculate_lux function is -1 when it should 
be 0 (sensor correctly read that light was off).

I think the bug is that a zero c0 value (approximated value of ch0) is 
misinterpreted as an error. 
Signed-off-by: NMichele Jr De Candia <michele.decandia@valueteam.com>
Acked-by: NRodolfo Giometti <giometti@linux.it>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Based on earlier work by Jon Smirl and Jochen Friedrich.

Update most new-style i2c drivers to use standard module aliasing
instead of the old driver_name/type driver matching scheme. I've
left the video drivers apart (except for SoC camera drivers) as
they're a bit more diffcult to deal with, they'll have their own
patch later.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Jon Smirl <jonsmirl@gmail.com>
Cc: Jochen Friedrich <jochen@scram.de>

Based on earlier work by Jon Smirl and Jochen Friedrich.

This patch allows new-style i2c chip drivers to have alias names using
the official kernel aliasing system and MODULE_DEVICE_TABLE(). At this
point, the old i2c driver binding scheme (driver_name/type) is still
supported.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Jochen Friedrich <jochen@scram.de>
Cc: Jon Smirl <jonsmirl@gmail.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>

Signed-off-by: NRodolfo Giometti <giometti@linux.it>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

There's some redundancy in the tsl2550 initialization sequence. It is
powering up the device twice, and setting the operating mode twice
too. Setting things just once saves SMBus transactions, which aren't
always cheap, speeding up the device initialization.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Rodolfo Giometti <giometti@linux.it>

Add support for Taos TSL2550 ambient light sensors.
(http://www.taosinc.com/product_detail.asp?cateid=4&proid=18).
Signed-off-by: NRodolfo Giometti <giometti@linux.it>
Signed-off-by: NJean Delvare <khali@linux-fr.org>