ltc2978 5.3 KB
Newer Older
1 2 3 4
Kernel driver ltc2978
=====================

Supported chips:
5 6 7 8
  * Linear Technology LTC2974
    Prefix: 'ltc2974'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc2974
9 10 11 12
  * Linear Technology LTC2977
    Prefix: 'ltc2977'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc2977
13
  * Linear Technology LTC2978, LTC2978A
14 15
    Prefix: 'ltc2978'
    Addresses scanned: -
16
    Datasheet: http://www.linear.com/product/ltc2978
17
    	       http://www.linear.com/product/ltc2978a
18 19 20
  * Linear Technology LTC3880
    Prefix: 'ltc3880'
    Addresses scanned: -
21
    Datasheet: http://www.linear.com/product/ltc3880
22 23 24 25
  * Linear Technology LTC3883
    Prefix: 'ltc3883'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc3883
26 27 28 29
  * Linear Technology LTM4676
    Prefix: 'ltm4676'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltm4676
30

31
Author: Guenter Roeck <linux@roeck-us.net>
32 33 34 35 36


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

37
LTC2974 is a quad digital power supply manager. LTC2978 is an octal power supply
38 39
monitor. LTC2977 is a pin compatible replacement for LTC2978. LTC3880 is a dual
output poly-phase step-down DC/DC controller. LTC3883 is a single phase
40 41
step-down DC/DC controller. LTM4676 is a dual 13A or single 26A uModule
regulator.
42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62


Usage Notes
-----------

This driver does not probe for PMBus devices. You will have to instantiate
devices explicitly.

Example: the following commands will load the driver for an LTC2978 at address
0x60 on I2C bus #1:

# modprobe ltc2978
# echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device


Sysfs attributes
----------------

in1_label		"vin"
in1_input		Measured input voltage.
in1_min			Minimum input voltage.
63 64 65 66
in1_max			Maximum input voltage.
			LTC2974, LTC2977, and LTC2978 only.
in1_lcrit		Critical minimum input voltage.
			LTC2974, LTC2977, and LTC2978 only.
67 68
in1_crit		Critical maximum input voltage.
in1_min_alarm		Input voltage low alarm.
69 70 71 72
in1_max_alarm		Input voltage high alarm.
			LTC2974, LTC2977, and LTC2978 only.
in1_lcrit_alarm		Input voltage critical low alarm.
			LTC2974, LTC2977, and LTC2978 only.
73
in1_crit_alarm		Input voltage critical high alarm.
74 75
in1_lowest		Lowest input voltage.
			LTC2974, LTC2977, and LTC2978 only.
76
in1_highest		Highest input voltage.
77
in1_reset_history	Reset input voltage history.
78

79 80
in[N]_label		"vout[1-8]".
			LTC2974: N=2-5
81
			LTC2977: N=2-9
82
			LTC2978: N=2-9
83
			LTC3880, LTM4676: N=2-3
84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
			LTC3883: N=2
in[N]_input		Measured output voltage.
in[N]_min		Minimum output voltage.
in[N]_max		Maximum output voltage.
in[N]_lcrit		Critical minimum output voltage.
in[N]_crit		Critical maximum output voltage.
in[N]_min_alarm		Output voltage low alarm.
in[N]_max_alarm		Output voltage high alarm.
in[N]_lcrit_alarm	Output voltage critical low alarm.
in[N]_crit_alarm	Output voltage critical high alarm.
in[N]_lowest		Lowest output voltage. LTC2974 and LTC2978 only.
in[N]_highest		Highest output voltage.
in[N]_reset_history	Reset output voltage history.

temp[N]_input		Measured temperature.
			On LTC2974, temp[1-4] report external temperatures,
			and temp5 reports the chip temperature.
101 102
			On LTC2977 and LTC2978, only one temperature measurement
			is supported and reports the chip temperature.
103
			On LTC3880 and LTM4676, temp1 and temp2 report external
104 105 106
			temperatures, and temp3 reports the chip temperature.
			On LTC3883, temp1 reports an external temperature,
			and temp2 reports the chip temperature.
107
temp[N]_min		Mimimum temperature. LTC2974, LCT2977, and LTC2978 only.
108 109 110
temp[N]_max		Maximum temperature.
temp[N]_lcrit		Critical low temperature.
temp[N]_crit		Critical high temperature.
111 112
temp[N]_min_alarm	Temperature low alarm.
			LTC2974, LTC2977, and LTC2978 only.
113 114 115
temp[N]_max_alarm	Temperature high alarm.
temp[N]_lcrit_alarm	Temperature critical low alarm.
temp[N]_crit_alarm	Temperature critical high alarm.
116 117
temp[N]_lowest		Lowest measured temperature.
			LTC2974, LTC2977, and LTC2978 only.
118 119 120 121 122 123 124 125 126 127 128
			Not supported for chip temperature sensor on LTC2974.
temp[N]_highest		Highest measured temperature. Not supported for chip
			temperature sensor on LTC2974.
temp[N]_reset_history	Reset temperature history. Not supported for chip
			temperature sensor on LTC2974.

power1_label		"pin". LTC3883 only.
power1_input		Measured input power.

power[N]_label		"pout[1-4]".
			LTC2974: N=1-4
129
			LTC2977: Not supported
130
			LTC2978: Not supported
131
			LTC3880, LTM4676: N=1-2
132 133 134
			LTC3883: N=2
power[N]_input		Measured output power.

135
curr1_label		"iin". LTC3880, LTC3883, and LTM4676 only.
136 137 138
curr1_input		Measured input current.
curr1_max		Maximum input current.
curr1_max_alarm		Input current high alarm.
139 140 141 142 143
curr1_highest		Highest input current. LTC3883 only.
curr1_reset_history	Reset input current history. LTC3883 only.

curr[N]_label		"iout[1-4]".
			LTC2974: N=1-4
144
			LTC2977: not supported
145
			LTC2978: not supported
146
			LTC3880, LTM4676: N=2-3
147 148 149 150 151 152 153 154 155 156 157
			LTC3883: N=2
curr[N]_input		Measured output current.
curr[N]_max		Maximum output current.
curr[N]_crit		Critical high output current.
curr[N]_lcrit		Critical low output current. LTC2974 only.
curr[N]_max_alarm	Output current high alarm.
curr[N]_crit_alarm	Output current critical high alarm.
curr[N]_lcrit_alarm	Output current critical low alarm. LTC2974 only.
curr[N]_lowest		Lowest output current. LTC2974 only.
curr[N]_highest		Highest output current.
curr[N]_reset_history	Reset output current history.