[PATCH] HWMON: w83791d: New hardware monitoring driver for the Winbond W83791D

Add support for the w83791d sensor chip. The w83791d hardware is
somewhere between the w83781d and the w83792d and this driver code
is derived from the code that supports those chips.

Signed-off-by: Charles Spirakis <bezaur@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 113 insertions, 0 deletions

diff --git a/Documentation/hwmon/w83791d b/Documentation/hwmon/w83791d
new file mode 100644
index 000000000000..83a3836289c2
--- /dev/null
+++ b/Documentation/hwmon/w83791d
@@ -0,0 +1,113 @@
+Kernel driver w83791d
+=====================
+
+Supported chips:
+  * Winbond W83791D
+    Prefix: 'w83791d'
+    Addresses scanned: I2C 0x2c - 0x2f
+    Datasheet: http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83791Da.pdf
+
+Author: Charles Spirakis <bezaur@gmail.com>
+
+This driver was derived from the w83781d.c and w83792d.c source files.
+
+Credits:
+  w83781d.c:
+    Frodo Looijaard <frodol@dds.nl>,
+    Philip Edelbrock <phil@netroedge.com>,
+    and Mark Studebaker <mdsxyz123@yahoo.com>
+  w83792d.c:
+    Chunhao Huang <DZShen@Winbond.com.tw>,
+    Rudolf Marek <r.marek@sh.cvut.cz>
+
+Module Parameters
+-----------------
+
+* init boolean
+  (default 0)
+  Use 'init=1' to have the driver do extra software initializations.
+  The default behavior is to do the minimum initialization possible
+  and depend on the BIOS to properly setup the chip. If you know you
+  have a w83791d and you're having problems, try init=1 before trying
+  reset=1.
+
+* reset boolean
+  (default 0)
+  Use 'reset=1' to reset the chip (via index 0x40, bit 7). The default
+  behavior is no chip reset to preserve BIOS settings.
+
+* force_subclients=bus,caddr,saddr,saddr
+  This is used to force the i2c addresses for subclients of
+  a certain chip. Example usage is `force_subclients=0,0x2f,0x4a,0x4b'
+  to force the subclients of chip 0x2f on bus 0 to i2c addresses
+  0x4a and 0x4b.
+
+
+Description
+-----------
+
+This driver implements support for the Winbond W83791D chip.
+
+Detection of the chip can sometimes be foiled because it can be in an
+internal state that allows no clean access (Bank with ID register is not
+currently selected). If you know the address of the chip, use a 'force'
+parameter; this will put it into a more well-behaved state first.
+
+The driver implements three temperature sensors, five fan rotation speed
+sensors, and ten voltage sensors.
+
+Temperatures are measured in degrees Celsius and measurement resolution is 1
+degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when
+the temperature gets higher than the Overtemperature Shutdown value; it stays
+on until the temperature falls below the Hysteresis value.
+
+Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
+triggered if the rotation speed has dropped below a programmable limit. Fan
+readings can be divided by a programmable divider (1, 2, 4, 8 for fan 1/2/3
+and 1, 2, 4, 8, 16, 32, 64 or 128 for fan 4/5) to give the readings more
+range or accuracy.
+
+Voltage sensors (also known as IN sensors) report their values in millivolts.
+An alarm is triggered if the voltage has crossed a programmable minimum
+or maximum limit.
+
+Alarms are provided as output from a "realtime status register". The
+following bits are defined:
+
+bit - alarm on:
+0  - Vcore
+1  - VINR0
+2  - +3.3VIN
+3  - 5VDD
+4  - temp1
+5  - temp2
+6  - fan1
+7  - fan2
+8  - +12VIN
+9  - -12VIN
+10 - -5VIN
+11 - fan3
+12 - chassis
+13 - temp3
+14 - VINR1
+15 - reserved
+16 - tart1
+17 - tart2
+18 - tart3
+19 - VSB
+20 - VBAT
+21 - fan4
+22 - fan5
+23 - reserved
+
+When an alarm goes off, you can be warned by a beeping signal through your
+computer speaker. It is possible to enable all beeping globally, or only
+the beeping for some alarms.
+
+The driver only reads the chip values each 3 seconds; reading them more
+often will do no harm, but will return 'old' values.
+
+W83791D TODO:
+---------------
+Provide a patch for per-file alarms as discussed on the mailing list
+Provide a patch for smart-fan control (still need appropriate motherboard/fans)