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authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-03 22:56:35 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-03 22:56:35 -0400
commitddcf6600b133697adbafd96e080818bdc0dfd028 (patch)
treef382f8eaca3cc2d298542ae9599ce49884127d0e /Documentation/hwmon
parentc16bfeb264decb964742067f02fdd51494e25e64 (diff)
parenta50d9a4d9ad3c71341788099d733e4151b8a511b (diff)
Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon updates from Guenter Roeck: - new driver to support GMT G762/G763 pwm fan controllers - add support for DS1631, DS1721, and DS1731 to ds1621 driver - remove detect function from ds1621 driver as unreliable - bug fixes in nct6775, iio_hwmon, and adm1021 drivers - remove redundant platform_set_drvdata in various drivers - add device tree support to ina2xx driver * tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: hwmon: (ds1621) Fix temperature rounding operations hwmon: (nct6775) Drop unsupported fan alarm attributes for NCT6775 hwmon: (nct6775) Fix temperature alarm attributes Add support for GMT G762/G763 PWM fan controllers hwmon: (ina2xx) Add device tree support to pass the shunt resistor hwmon: (ds1621) Update documentation hwmon: (ds1621) Add DS1731 chip support to ds1621 driver hwmon: (iio_hwmon) add alias table hwmon: (adm1021) Do not create min sysfs attributes for LM84 hwmon: (ds1621) Remove detect function hwmon: (ds1621) Add ds1631 chip support to ds1621 driver and documentation hwmon: (ds1621) Add ds1721 update interval sysfs attribute hwmon: (ds1621) Add ds1721 chip support hwmon: (w83627ehf) Remove redundant platform_set_drvdata() hwmon: (ntc_thermistor) Remove redundant platform_set_drvdata() hwmon: (i5k_amb) Remove redundant platform_set_drvdata() hwmon: (coretemp) Remove redundant platform_set_drvdata() hwmon: (abituguru3) Remove redundant platform_set_drvdata()
Diffstat (limited to 'Documentation/hwmon')
-rw-r--r--Documentation/hwmon/ds1621144
-rw-r--r--Documentation/hwmon/g76265
-rw-r--r--Documentation/hwmon/ina2xx4
3 files changed, 202 insertions, 11 deletions
diff --git a/Documentation/hwmon/ds1621 b/Documentation/hwmon/ds1621
index 5e97f333c4df..896cdc972ca8 100644
--- a/Documentation/hwmon/ds1621
+++ b/Documentation/hwmon/ds1621
@@ -2,16 +2,30 @@ Kernel driver ds1621
2==================== 2====================
3 3
4Supported chips: 4Supported chips:
5 * Dallas Semiconductor DS1621 5 * Dallas Semiconductor / Maxim Integrated DS1621
6 Prefix: 'ds1621' 6 Prefix: 'ds1621'
7 Addresses scanned: I2C 0x48 - 0x4f 7 Addresses scanned: none
8 Datasheet: Publicly available at the Dallas Semiconductor website 8 Datasheet: Publicly available from www.maximintegrated.com
9 http://www.dalsemi.com/ 9
10 * Dallas Semiconductor DS1625 10 * Dallas Semiconductor DS1625
11 Prefix: 'ds1621' 11 Prefix: 'ds1625'
12 Addresses scanned: I2C 0x48 - 0x4f 12 Addresses scanned: none
13 Datasheet: Publicly available at the Dallas Semiconductor website 13 Datasheet: Publicly available from www.datasheetarchive.com
14 http://www.dalsemi.com/ 14
15 * Maxim Integrated DS1631
16 Prefix: 'ds1631'
17 Addresses scanned: none
18 Datasheet: Publicly available from www.maximintegrated.com
19
20 * Maxim Integrated DS1721
21 Prefix: 'ds1721'
22 Addresses scanned: none
23 Datasheet: Publicly available from www.maximintegrated.com
24
25 * Maxim Integrated DS1731
26 Prefix: 'ds1731'
27 Addresses scanned: none
28 Datasheet: Publicly available from www.maximintegrated.com
15 29
16Authors: 30Authors:
17 Christian W. Zuckschwerdt <zany@triq.net> 31 Christian W. Zuckschwerdt <zany@triq.net>
@@ -59,5 +73,115 @@ any of the limits have ever been met or exceeded since last power-up or
59reset. Be aware: When testing, it showed that the status of Tout can change 73reset. Be aware: When testing, it showed that the status of Tout can change
60with neither of the alarms set. 74with neither of the alarms set.
61 75
62Temperature conversion of the DS1621 takes up to 1000ms; internal access to 76Since there is no version or vendor identification register, there is
63non-volatile registers may last for 10ms or below. 77no unique identification for these devices. Therefore, explicit device
78instantiation is required for correct device identification and functionality
79(one device per address in this address range: 0x48..0x4f).
80
81The DS1625 is pin compatible and functionally equivalent with the DS1621,
82but the DS1621 is meant to replace it. The DS1631, DS1721, and DS1731 are
83also pin compatible with the DS1621 and provide multi-resolution support.
84
85Additionally, the DS1721 data sheet says the temperature flags (THF and TLF)
86are used internally, however, these flags do get set and cleared as the actual
87temperature crosses the min or max settings (which by default are set to 75
88and 80 degrees respectively).
89
90Temperature Conversion:
91-----------------------
92DS1621 - 750ms (older devices may take up to 1000ms)
93DS1625 - 500ms
94DS1631 - 93ms..750ms for 9..12 bits resolution, respectively.
95DS1721 - 93ms..750ms for 9..12 bits resolution, respectively.
96DS1731 - 93ms..750ms for 9..12 bits resolution, respectively.
97
98Note:
99On the DS1621, internal access to non-volatile registers may last for 10ms
100or less (unverified on the other devices).
101
102Temperature Accuracy:
103---------------------
104DS1621: +/- 0.5 degree Celsius (from 0 to +70 degrees)
105DS1625: +/- 0.5 degree Celsius (from 0 to +70 degrees)
106DS1631: +/- 0.5 degree Celsius (from 0 to +70 degrees)
107DS1721: +/- 1.0 degree Celsius (from -10 to +85 degrees)
108DS1731: +/- 1.0 degree Celsius (from -10 to +85 degrees)
109
110Note:
111Please refer to the device datasheets for accuracy at other temperatures.
112
113Temperature Resolution:
114-----------------------
115As mentioned above, the DS1631, DS1721, and DS1731 provide multi-resolution
116support, which is achieved via the R0 and R1 config register bits, where:
117
118R0..R1
119------
120 0 0 => 9 bits, 0.5 degrees Celcius
121 1 0 => 10 bits, 0.25 degrees Celcius
122 0 1 => 11 bits, 0.125 degrees Celcius
123 1 1 => 12 bits, 0.0625 degrees Celcius
124
125Note:
126At initial device power-on, the default resolution is set to 12-bits.
127
128The resolution mode for the DS1631, DS1721, or DS1731 can be changed from
129userspace, via the device 'update_interval' sysfs attribute. This attribute
130will normalize the range of input values to the device maximum resolution
131values defined in the datasheet as follows:
132
133Resolution Conversion Time Input Range
134 (C/LSB) (msec) (msec)
135------------------------------------------------
1360.5 93.75 0....94
1370.25 187.5 95...187
1380.125 375 188..375
1390.0625 750 376..infinity
140------------------------------------------------
141
142The following examples show how the 'update_interval' attribute can be
143used to change the conversion time:
144
145$ cat update_interval
146750
147$ cat temp1_input
14822062
149$
150$ echo 300 > update_interval
151$ cat update_interval
152375
153$ cat temp1_input
15422125
155$
156$ echo 150 > update_interval
157$ cat update_interval
158188
159$ cat temp1_input
16022250
161$
162$ echo 1 > update_interval
163$ cat update_interval
16494
165$ cat temp1_input
16622000
167$
168$ echo 1000 > update_interval
169$ cat update_interval
170750
171$ cat temp1_input
17222062
173$
174
175As shown, the ds1621 driver automatically adjusts the 'update_interval'
176user input, via a step function. Reading back the 'update_interval' value
177after a write operation provides the conversion time used by the device.
178
179Mathematically, the resolution can be derived from the conversion time
180via the following function:
181
182 g(x) = 0.5 * [minimum_conversion_time/x]
183
184where:
185 -> 'x' = the output from 'update_interval'
186 -> 'g(x)' = the resolution in degrees C per LSB.
187 -> 93.75ms = minimum conversion time
diff --git a/Documentation/hwmon/g762 b/Documentation/hwmon/g762
new file mode 100644
index 000000000000..923db9c5b5bc
--- /dev/null
+++ b/Documentation/hwmon/g762
@@ -0,0 +1,65 @@
1Kernel driver g762
2==================
3
4The GMT G762 Fan Speed PWM Controller is connected directly to a fan
5and performs closed-loop or open-loop control of the fan speed. Two
6modes - PWM or DC - are supported by the device.
7
8For additional information, a detailed datasheet is available at
9http://natisbad.org/NAS/ref/GMT_EDS-762_763-080710-0.2.pdf. sysfs
10bindings are described in Documentation/hwmon/sysfs-interface.
11
12The following entries are available to the user in a subdirectory of
13/sys/bus/i2c/drivers/g762/ to control the operation of the device.
14This can be done manually using the following entries but is usually
15done via a userland daemon like fancontrol.
16
17Note that those entries do not provide ways to setup the specific
18hardware characteristics of the system (reference clock, pulses per
19fan revolution, ...); Those can be modified via devicetree bindings
20documented in Documentation/devicetree/bindings/hwmon/g762.txt or
21using a specific platform_data structure in board initialization
22file (see include/linux/platform_data/g762.h).
23
24 fan1_target: set desired fan speed. This only makes sense in closed-loop
25 fan speed control (i.e. when pwm1_enable is set to 2).
26
27 fan1_input: provide current fan rotation value in RPM as reported by
28 the fan to the device.
29
30 fan1_div: fan clock divisor. Supported value are 1, 2, 4 and 8.
31
32 fan1_pulses: number of pulses per fan revolution. Supported values
33 are 2 and 4.
34
35 fan1_fault: reports fan failure, i.e. no transition on fan gear pin for
36 about 0.7s (if the fan is not voluntarily set off).
37
38 fan1_alarm: in closed-loop control mode, if fan RPM value is 25% out
39 of the programmed value for over 6 seconds 'fan1_alarm' is
40 set to 1.
41
42 pwm1_enable: set current fan speed control mode i.e. 1 for manual fan
43 speed control (open-loop) via pwm1 described below, 2 for
44 automatic fan speed control (closed-loop) via fan1_target
45 above.
46
47 pwm1_mode: set or get fan driving mode: 1 for PWM mode, 0 for DC mode.
48
49 pwm1: get or set PWM fan control value in open-loop mode. This is an
50 integer value between 0 and 255. 0 stops the fan, 255 makes
51 it run at full speed.
52
53Both in PWM mode ('pwm1_mode' set to 1) and DC mode ('pwm1_mode' set to 0),
54when current fan speed control mode is open-loop ('pwm1_enable' set to 1),
55the fan speed is programmed by setting a value between 0 and 255 via 'pwm1'
56entry (0 stops the fan, 255 makes it run at full speed). In closed-loop mode
57('pwm1_enable' set to 2), the expected rotation speed in RPM can be passed to
58the chip via 'fan1_target'. In closed-loop mode, the target speed is compared
59with current speed (available via 'fan1_input') by the device and a feedback
60is performed to match that target value. The fan speed value is computed
61based on the parameters associated with the physical characteristics of the
62system: a reference clock source frequency, a number of pulses per fan
63revolution, etc.
64
65Note that the driver will update its values at most once per second.
diff --git a/Documentation/hwmon/ina2xx b/Documentation/hwmon/ina2xx
index 03444f9d833f..4223c2d3b508 100644
--- a/Documentation/hwmon/ina2xx
+++ b/Documentation/hwmon/ina2xx
@@ -44,4 +44,6 @@ The INA226 monitors both a shunt voltage drop and bus supply voltage.
44The INA230 is a high or low side current shunt and power monitor with an I2C 44The INA230 is a high or low side current shunt and power monitor with an I2C
45interface. The INA230 monitors both a shunt voltage drop and bus supply voltage. 45interface. The INA230 monitors both a shunt voltage drop and bus supply voltage.
46 46
47The shunt value in micro-ohms can be set via platform data. 47The shunt value in micro-ohms can be set via platform data or device tree.
48Please refer to the Documentation/devicetree/bindings/i2c/ina2xx.txt for bindings
49if the device tree is used.