1 Kernel driver pc87360 2 ===================== 3 4 Supported chips: 5 6 * National Semiconductor PC87360, PC87363, PC87364, PC87365 and PC87366 7 8 Prefixes: 'pc87360', 'pc87363', 'pc87364', 'pc87365', 'pc87366' 9 10 Addresses scanned: none, address read from Super I/O config space 11 12 Datasheets: No longer available 13 14 Authors: Jean Delvare <jdelvare@suse.de> 15 16 Thanks to Sandeep Mehta, Tonko de Rooy and Daniel Ceregatti for testing. 17 18 Thanks to Rudolf Marek for helping me investigate conversion issues. 19 20 21 Module Parameters 22 ----------------- 23 24 * init int 25 Chip initialization level: 26 27 - 0: None 28 - **1**: Forcibly enable internal voltage and temperature channels, 29 except in9 30 - 2: Forcibly enable all voltage and temperature channels, except in9 31 - 3: Forcibly enable all voltage and temperature channels, including in9 32 33 Note that this parameter has no effect for the PC87360, PC87363 and PC87364 34 chips. 35 36 Also note that for the PC87366, initialization levels 2 and 3 don't enable 37 all temperature channels, because some of them share pins with each other, 38 so they can't be used at the same time. 39 40 41 Description 42 ----------- 43 44 The National Semiconductor PC87360 Super I/O chip contains monitoring and 45 PWM control circuitry for two fans. The PC87363 chip is similar, and the 46 PC87364 chip has monitoring and PWM control for a third fan. 47 48 The National Semiconductor PC87365 and PC87366 Super I/O chips are complete 49 hardware monitoring chipsets, not only controlling and monitoring three fans, 50 but also monitoring eleven voltage inputs and two (PC87365) or up to four 51 (PC87366) temperatures. 52 53 =========== ======= ======= ======= ======= ===== 54 Chip #vin #fan #pwm #temp devid 55 =========== ======= ======= ======= ======= ===== 56 PC87360 - 2 2 - 0xE1 57 PC87363 - 2 2 - 0xE8 58 PC87364 - 3 3 - 0xE4 59 PC87365 11 3 3 2 0xE5 60 PC87366 11 3 3 3-4 0xE9 61 =========== ======= ======= ======= ======= ===== 62 63 The driver assumes that no more than one chip is present, and one of the 64 standard Super I/O addresses is used (0x2E/0x2F or 0x4E/0x4F) 65 66 Fan Monitoring 67 -------------- 68 69 Fan rotation speeds are reported in RPM (revolutions per minute). An alarm 70 is triggered if the rotation speed has dropped below a programmable limit. 71 A different alarm is triggered if the fan speed is too low to be measured. 72 73 Fan readings are affected by a programmable clock divider, giving the 74 readings more range or accuracy. Usually, users have to learn how it works, 75 but this driver implements dynamic clock divider selection, so you don't 76 have to care no more. 77 78 For reference, here are a few values about clock dividers: 79 80 =========== =============== =============== =========== 81 slowest accuracy highest 82 measurable around 3000 accurate 83 divider speed (RPM) RPM (RPM) speed (RPM) 84 =========== =============== =============== =========== 85 1 1882 18 6928 86 2 941 37 4898 87 4 470 74 3464 88 8 235 150 2449 89 =========== =============== =============== =========== 90 91 For the curious, here is how the values above were computed: 92 93 * slowest measurable speed: clock/(255*divider) 94 * accuracy around 3000 RPM: 3000^2/clock 95 * highest accurate speed: sqrt(clock*100) 96 97 The clock speed for the PC87360 family is 480 kHz. I arbitrarily chose 100 98 RPM as the lowest acceptable accuracy. 99 100 As mentioned above, you don't have to care about this no more. 101 102 Note that not all RPM values can be represented, even when the best clock 103 divider is selected. This is not only true for the measured speeds, but 104 also for the programmable low limits, so don't be surprised if you try to 105 set, say, fan1_min to 2900 and it finally reads 2909. 106 107 108 Fan Control 109 ----------- 110 111 PWM (pulse width modulation) values range from 0 to 255, with 0 meaning 112 that the fan is stopped, and 255 meaning that the fan goes at full speed. 113 114 Be extremely careful when changing PWM values. Low PWM values, even 115 non-zero, can stop the fan, which may cause irreversible damage to your 116 hardware if temperature increases too much. When changing PWM values, go 117 step by step and keep an eye on temperatures. 118 119 One user reported problems with PWM. Changing PWM values would break fan 120 speed readings. No explanation nor fix could be found. 121 122 123 Temperature Monitoring 124 ---------------------- 125 126 Temperatures are reported in degrees Celsius. Each temperature measured has 127 associated low, high and overtemperature limits, each of which triggers an 128 alarm when crossed. 129 130 The first two temperature channels are external. The third one (PC87366 131 only) is internal. 132 133 The PC87366 has three additional temperature channels, based on 134 thermistors (as opposed to thermal diodes for the first three temperature 135 channels). For technical reasons, these channels are held by the VLM 136 (voltage level monitor) logical device, not the TMS (temperature 137 measurement) one. As a consequence, these temperatures are exported as 138 voltages, and converted into temperatures in user-space. 139 140 Note that these three additional channels share their pins with the 141 external thermal diode channels, so you (physically) can't use them all at 142 the same time. Although it should be possible to mix the two sensor types, 143 the documents from National Semiconductor suggest that motherboard 144 manufacturers should choose one type and stick to it. So you will more 145 likely have either channels 1 to 3 (thermal diodes) or 3 to 6 (internal 146 thermal diode, and thermistors). 147 148 149 Voltage Monitoring 150 ------------------ 151 152 Voltages are reported relatively to a reference voltage, either internal or 153 external. Some of them (in7:Vsb, in8:Vdd and in10:AVdd) are divided by two 154 internally, you will have to compensate in sensors.conf. Others (in0 to in6) 155 are likely to be divided externally. The meaning of each of these inputs as 156 well as the values of the resistors used for division is left to the 157 motherboard manufacturers, so you will have to document yourself and edit 158 sensors.conf accordingly. National Semiconductor has a document with 159 recommended resistor values for some voltages, but this still leaves much 160 room for per motherboard specificities, unfortunately. Even worse, 161 motherboard manufacturers don't seem to care about National Semiconductor's 162 recommendations. 163 164 Each voltage measured has associated low and high limits, each of which 165 triggers an alarm when crossed. 166 167 When available, VID inputs are used to provide the nominal CPU Core voltage. 168 The driver will default to VRM 9.0, but this can be changed from user-space. 169 The chipsets can handle two sets of VID inputs (on dual-CPU systems), but 170 the driver will only export one for now. This may change later if there is 171 a need. 172 173 174 General Remarks 175 --------------- 176 177 If an alarm triggers, it will remain triggered until the hardware register 178 is read at least once. This means that the cause for the alarm may already 179 have disappeared! Note that all hardware registers are read whenever any 180 data is read (unless it is less than 2 seconds since the last update, in 181 which case cached values are returned instead). As a consequence, when 182 a once-only alarm triggers, it may take 2 seconds for it to show, and 2 183 more seconds for it to disappear. 184 185 Monitoring of in9 isn't enabled at lower init levels (<3) because that 186 channel measures the battery voltage (Vbat). It is a known fact that 187 repeatedly sampling the battery voltage reduces its lifetime. National 188 Semiconductor smartly designed their chipset so that in9 is sampled only 189 once every 1024 sampling cycles (that is every 34 minutes at the default 190 sampling rate), so the effect is attenuated, but still present. 191 192 193 Limitations 194 ----------- 195 196 The datasheets suggests that some values (fan mins, fan dividers) 197 shouldn't be changed once the monitoring has started, but we ignore that 198 recommendation. We'll reconsider if it actually causes trouble.
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.