[GitHub/mt8127/android_kernel_alcatel_ttab.git] / Documentation / hwmon / w83l785ts

Kernel driver w83l785ts
=======================

Supported chips:
  * Winbond W83L785TS-S
    Prefix: 'w83l785ts'
    Addresses scanned: I2C 0x2e
    Datasheet: Publicly available at the Winbond USA website
               http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L785TS-S.pdf

Authors:
        Jean Delvare <khali@linux-fr.org>

Description
-----------

The W83L785TS-S is a digital temperature sensor. It senses the
temperature of a single external diode. The high limit is
theoretically defined as 85 or 100 degrees C through a combination
of external resistors, so the user cannot change it. Values seen so
far suggest that the two possible limits are actually 95 and 110
degrees C. The datasheet is rather poor and obviously inaccurate
on several points including this one.

All temperature values are given in degrees Celsius. Resolution
is 1.0 degree. See the datasheet for details.

The w83l785ts driver will not update its values more frequently than
every other second; reading them more often will do no harm, but will
return 'old' values.

Known Issues
------------

On some systems (Asus), the BIOS is known to interfere with the driver
and cause read errors. Or maybe the W83L785TS-S chip is simply unreliable,
we don't really know. The driver will retry a given number of times
(5 by default) and then give up, returning the old value (or 0 if
there is no old value). It seems to work well enough so that you should
not notice anything. Thanks to James Bolt for helping test this feature.
Commit	Line	Data
7f15b664 RM	1	Kernel driver w83l785ts
	2	=======================
	3
	4	Supported chips:
	5	* Winbond W83L785TS-S
	6	Prefix: 'w83l785ts'
	7	Addresses scanned: I2C 0x2e
	8	Datasheet: Publicly available at the Winbond USA website
	9	http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L785TS-S.pdf
	10
	11	Authors:
	12	Jean Delvare <khali@linux-fr.org>
	13
	14	Description
	15	-----------
	16
	17	The W83L785TS-S is a digital temperature sensor. It senses the
	18	temperature of a single external diode. The high limit is
	19	theoretically defined as 85 or 100 degrees C through a combination
	20	of external resistors, so the user cannot change it. Values seen so
	21	far suggest that the two possible limits are actually 95 and 110
	22	degrees C. The datasheet is rather poor and obviously inaccurate
	23	on several points including this one.
	24
	25	All temperature values are given in degrees Celsius. Resolution
	26	is 1.0 degree. See the datasheet for details.
	27
	28	The w83l785ts driver will not update its values more frequently than
	29	every other second; reading them more often will do no harm, but will
	30	return 'old' values.
	31
	32	Known Issues
	33	------------
	34
	35	On some systems (Asus), the BIOS is known to interfere with the driver
4040c415 JD	36	and cause read errors. Or maybe the W83L785TS-S chip is simply unreliable,
4040c415 JD	37	we don't really know. The driver will retry a given number of times
7f15b664 RM	38	(5 by default) and then give up, returning the old value (or 0 if
	39	there is no old value). It seems to work well enough so that you should
	40	not notice anything. Thanks to James Bolt for helping test this feature.