1 Kernel driver lm93
2 ==================
3
4 Supported chips:
5
6 * National Semiconductor LM93
7
8 Prefix 'lm93'
9
10 Addresses scanned: I2C 0x2c-0x2e
11
12 Datasheet: http://www.national.com/ds.cgi/
13
14 * National Semiconductor LM94
15
16 Prefix 'lm94'
17
18 Addresses scanned: I2C 0x2c-0x2e
19
20 Datasheet: http://www.national.com/ds.cgi/
21
22
23 Authors:
24 - Mark M. Hoffman <mhoffman@lightlink.c
25 - Ported to 2.6 by Eric J. Bowersox <er
26 - Adapted to 2.6.20 by Carsten Emde <ce
27 - Modified for mainline integration by<
28
29 Module Parameters
30 -----------------
31
32 * init: integer
33 Set to non-zero to force some initialization
34 * disable_block: integer
35 A "0" allows SMBus block data transactions i
36 disables SMBus block data transactions. The
37 * vccp_limit_type: integer array (2)
38 Configures in7 and in8 limit type, where 0 m
39 means relative. "Relative" here refers to "
40 VID" from the datasheet. It greatly simplif
41 only one set of limits (absolute or relative
42 time (even though the hardware is capable of
43 not a compelling use case for enabling both
44 is "0,0".
45 * vid_agtl: integer
46 A "0" configures the VID pins for V(ih) = 2.
47 A "1" configures the VID pins for V(ih) = 0.
48 (The latter setting is referred to as AGTL+
49 I.e. this parameter controls the VID pin inp
50 inputs are not working, try changing this.
51
52
53 Hardware Description
54 --------------------
55
56 (from the datasheet)
57
58 The LM93 hardware monitor has a two wire digit
59 SMBus 2.0. Using an 8-bit ADC, the LM93 measur
60 diode connected transistors as well as its own
61 voltages. To set fan speed, the LM93 has two P
62 controlled by up to four temperature zones. Th
63 table based. The LM93 includes a digital filte
64 temperature readings for better control of fan
65 tachometer inputs to measure fan speed. Limit
66 measured values are included. The LM93 builds
67 previous motherboard management ASICs and uses
68 (i.e. smart tachometer mode). It also adds mea
69 for dynamic Vccp monitoring and PROCHOT. It is
70 processor Xeon class motherboard with a minimu
71
72 LM94 is also supported in LM93 compatible mode
73 LM94 are not supported.
74
75
76 User Interface
77 --------------
78
79 #PROCHOT
80 ^^^^^^^^
81
82 The LM93 can monitor two #PROCHOT signals. Th
83 sysfs files prochot1, prochot2, prochot1_avg,
84 and prochot2_max. prochot1_max and prochot2_m
85 for #PROCHOT1 and #PROCHOT2, respectively. pr
86 the current readings for the most recent compl
87 value of prochot1_avg and prochot2_avg is some
88 exponential moving average (but not quite - ch
89 that this third value is calculated by the chi
90 from 0-255 where 0 indicates no throttling, an
91
92 The monitoring intervals for the two #PROCHOT
93 These intervals can be found in the sysfs file
94 prochot2_interval. The values in these files
95 #P1_PROCHOT and #P2_PROCHOT, respectively. Se
96 list will cause the driver to use the next lar
97 intervals are (in seconds):
98
99 #PROCHOT intervals:
100 0.73, 1.46, 2.9, 5.8, 11.7, 23.3, 46.6
101
102 It is possible to configure the LM93 to logica
103 signals. I.e. when #P1_PROCHOT is asserted, t
104 assert #P2_PROCHOT, and vice-versa. This mode
105 non-zero integer to the sysfs file prochot_sho
106
107 The LM93 can also override the #PROCHOT pins b
108 one or both of them. When overridden, the sig
109 a minimum pulse width of 5 clocks (at 22.5kHz
110 a maximum pulse width of 80 clocks (at 22.5kHz
111
112 The sysfs files prochot1_override and prochot2
113 integers which enable or disable the override
114 #P2_PROCHOT, respectively. The sysfs file pro
115 contains a value controlling the duty cycle fo
116 the override function is enabled. This value
117 indicating minimum duty cycle and 15 indicatin
118
119 #VRD_HOT
120 ^^^^^^^^
121
122 The LM93 can monitor two #VRD_HOT signals. The
123 sysfs files vrdhot1 and vrdhot2. There is one
124 which 1 indicates #VRD_HOT is asserted and 0 i
125 files are read-only.
126
127 Smart Tach Mode (from the datasheet)::
128
129 If a fan is driven using a low-side dr
130 output of the fan is corrupted. The LM
131 circuitry that allows an accurate tach
132 achieved despite the signal corruption
133 four signals are measured within 4 sec
134
135 Smart tach mode is enabled by the driver by wr
136 fan tachometer with a pwm) to the sysfs file f
137 will disable the function for that fan. Note
138 enabled if the PWM output frequency is 22500 H
139
140 Manual PWM
141 ^^^^^^^^^^
142
143 The LM93 has a fixed or override mode for the
144 are still some conditions that will override e
145 15.10.6 of the datasheet for details.) The sy
146 and pwm2_override are used to enable this mode
147 where 0 disables and 1 enables the manual cont
148 and pwm2 are used to set the manual duty cycle
149 where 0 is 0% duty cycle, and 255 is 100%. No
150 are constrained by the hardware. Selecting a v
151 will cause the driver to use the next largest
152 PWM mode is disabled, the value of pwm1 and pw
153 cycle chosen by the h/w.
154
155 PWM Output Frequency
156 ^^^^^^^^^^^^^^^^^^^^
157
158 The LM93 supports several different frequencie
159 The sysfs files pwm1_freq and pwm2_freq are us
160 frequency values are constrained by the hardwa
161 not available will cause the driver to use the
162 that this parameter has implications for the S
163
164 PWM Output Frequencies (in Hz):
165 12, 36, 48, 60, 72, 84, 96, 22500 (def
166
167 Automatic PWM
168 ^^^^^^^^^^^^^
169
170 The LM93 is capable of complex automatic fan c
171 points of configuration. To start, each PWM o
172 combination of eight control sources. The fin
173 individual control sources to which the PWM ou
174
175 The eight control sources are: temp1-temp4 (ak
176 #PROCHOT 1 & 2, and #VRDHOT 1 & 2. The bindin
177 in the sysfs files pwm<n>_auto_channels, where
178 a "0" disables it. The h/w default is 0x0f (al
179
180 ====== ===========
181 0x01 Temp 1
182 0x02 Temp 2
183 0x04 Temp 3
184 0x08 Temp 4
185 0x10 #PROCHOT 1
186 0x20 #PROCHOT 2
187 0x40 #VRDHOT 1
188 0x80 #VRDHOT 2
189 ====== ===========
190
191 The function y = f(x) takes a source temperatu
192 function of the LM93 is derived from a base te
193 temperature offsets. The base temperature is
194 sysfs files temp<n>_auto_base. The offsets ar
195 degrees C, with the value of offset <i> for te
196 contained in the file temp<n>_auto_offset<i>.
197 is 40C:
198
199 ========== ======================= ======
200 offset # temp<n>_auto_offset<i> range
201 ========== ======================= ======
202 1 0 -
203 2 0 -
204 3 1 40C -
205 4 1 41C -
206 5 2 42C -
207 6 2 44C -
208 7 2 48C -
209 8 2 50C -
210 9 2 52C -
211 10 2 54C -
212 11 2 56C -
213 12 2 58C -
214 - - > 60C
215 ========== ======================= ======
216
217 Valid offsets are in the range 0C <= x <= 7.5C
218
219 There is an independent base temperature for e
220 however, there are only two tables of offsets:
221 temp[34]. Therefore, any change to e.g. temp1
222 affect temp2_auto_offset<i>.
223
224 The LM93 can also apply hysteresis to the offs
225 oscillation between two steps in the offsets t
226 the sysfs files temp<n>_auto_offset_hyst. The
227 same representation as in temp<n>_auto_offset<
228
229 If a temperature reading falls below the base
230 will use the minimum PWM value. These values
231 temp<n>_auto_pwm_min. Note, there are only tw
232 and temp[34]. Therefore, any change to e.g. t
233 affect temp2_auto_pwm_min.
234
235 PWM Spin-Up Cycle
236 ^^^^^^^^^^^^^^^^^
237
238 A spin-up cycle occurs when a PWM output is co
239 some value > 0%. The LM93 supports a minimum
240 values are found in the sysfs files pwm<n>_aut
241 file has the same representation as other PWM
242 duration of the spin-up cycle is also configur
243 the sysfs files pwm<n>_auto_spinup_time. The v
244 the spin-up time in seconds. The available sp
245 the hardware. Selecting a value which is not
246 to use the next largest value.
247
248 Spin-up Durations:
249 0 (disabled, h/w default), 0.1, 0.25,
250
251 #PROCHOT and #VRDHOT PWM Ramping
252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
253
254 If the #PROCHOT or #VRDHOT signals are asserte
255 channel, the LM93 will ramp the PWM output up
256 steps. The duration of each step is configurab
257 one value each in seconds: pwm_auto_prochot_ra
258 The available ramp times are constrained by th
259 which is not available will cause the driver t
260
261 Ramp Times:
262 0 (disabled, h/w default) to 0.75 in 0
263
264 Fan Boost
265 ^^^^^^^^^
266
267 For each temperature channel, there is a boost
268 exceeds this limit, the LM93 will immediately
269 This limit is expressed in degrees C in the sy
270 There is also a hysteresis temperature for thi
271 limit is reached, the temperature channel must
272 the boost function is disabled. This temperat
273 C in the sysfs files temp<n>_auto_boost_hyst.
274
275 GPIO Pins
276 ^^^^^^^^^
277
278 The LM93 can monitor the logic level of four d
279 four tach input pins. GPIO0-GPIO3 correspond
280 All eight GPIOs are read by reading the bitmas
281 LSB is GPIO0, and the MSB is GPIO7.
282
283
284 LM93 Unique sysfs Files
285 -----------------------
286
287 =========================== ==================
288 file description
289 =========================== ==================
290 prochot<n> current #PROCHOT %
291 prochot<n>_avg moving average #PR
292 prochot<n>_max limit #PROCHOT %
293 prochot_short enable or disable
294 prochot<n>_override force #PROCHOT ass
295 prochot_override_duty_cycle duty cycle for the
296 #PROCHOT is overri
297 prochot<n>_interval #PROCHOT PWM sampl
298 vrdhot<n> 0 means negated, 1
299 fan<n>_smart_tach enable or disable
300 pwm<n>_auto_channels select control sou
301 pwm<n>_auto_spinup_min minimum duty cycle
302 pwm<n>_auto_spinup_time duration of spin-u
303 pwm_auto_prochot_ramp ramp time per step
304 pwm_auto_vrdhot_ramp ramp time per step
305 temp<n>_auto_base temperature channe
306 temp<n>_auto_offset[1-12] temperature channe
307 temp<n>_auto_offset_hyst temperature channe
308 temp<n>_auto_boost temperature channe
309 limit
310 temp<n>_auto_boost_hyst temperature channe
311 gpio input state of 8 G
312 =========================== ==================
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