Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.
1 Kernel driver pc87360 2 ===================== 3 4 Supported chips: 5 * National Semiconductor PC87360, PC87363, PC87364, PC87365 and PC87366 6 Prefixes: 'pc87360', 'pc87363', 'pc87364', 'pc87365', 'pc87366' 7 Addresses scanned: none, address read from Super I/O config space 8 Datasheets: No longer available 9 10 Authors: Jean Delvare <jdelvare@suse.de> 11 12 Thanks to Sandeep Mehta, Tonko de Rooy and Daniel Ceregatti for testing. 13 Thanks to Rudolf Marek for helping me investigate conversion issues. 14 15 16 Module Parameters 17 ----------------- 18 19 * init int 20 Chip initialization level: 21 0: None 22 *1: Forcibly enable internal voltage and temperature channels, except in9 23 2: Forcibly enable all voltage and temperature channels, except in9 24 3: Forcibly enable all voltage and temperature channels, including in9 25 26 Note that this parameter has no effect for the PC87360, PC87363 and PC87364 27 chips. 28 29 Also note that for the PC87366, initialization levels 2 and 3 don't enable 30 all temperature channels, because some of them share pins with each other, 31 so they can't be used at the same time. 32 33 34 Description 35 ----------- 36 37 The National Semiconductor PC87360 Super I/O chip contains monitoring and 38 PWM control circuitry for two fans. The PC87363 chip is similar, and the 39 PC87364 chip has monitoring and PWM control for a third fan. 40 41 The National Semiconductor PC87365 and PC87366 Super I/O chips are complete 42 hardware monitoring chipsets, not only controlling and monitoring three fans, 43 but also monitoring eleven voltage inputs and two (PC87365) or up to four 44 (PC87366) temperatures. 45 46 Chip #vin #fan #pwm #temp devid 47 48 PC87360 - 2 2 - 0xE1 49 PC87363 - 2 2 - 0xE8 50 PC87364 - 3 3 - 0xE4 51 PC87365 11 3 3 2 0xE5 52 PC87366 11 3 3 3-4 0xE9 53 54 The driver assumes that no more than one chip is present, and one of the 55 standard Super I/O addresses is used (0x2E/0x2F or 0x4E/0x4F) 56 57 Fan Monitoring 58 -------------- 59 60 Fan rotation speeds are reported in RPM (revolutions per minute). An alarm 61 is triggered if the rotation speed has dropped below a programmable limit. 62 A different alarm is triggered if the fan speed is too low to be measured. 63 64 Fan readings are affected by a programmable clock divider, giving the 65 readings more range or accuracy. Usually, users have to learn how it works, 66 but this driver implements dynamic clock divider selection, so you don't 67 have to care no more. 68 69 For reference, here are a few values about clock dividers: 70 71 slowest accuracy highest 72 measurable around 3000 accurate 73 divider speed (RPM) RPM (RPM) speed (RPM) 74 1 1882 18 6928 75 2 941 37 4898 76 4 470 74 3464 77 8 235 150 2449 78 79 For the curious, here is how the values above were computed: 80 * slowest measurable speed: clock/(255*divider) 81 * accuracy around 3000 RPM: 3000^2/clock 82 * highest accurate speed: sqrt(clock*100) 83 The clock speed for the PC87360 family is 480 kHz. I arbitrarily chose 100 84 RPM as the lowest acceptable accuracy. 85 86 As mentioned above, you don't have to care about this no more. 87 88 Note that not all RPM values can be represented, even when the best clock 89 divider is selected. This is not only true for the measured speeds, but 90 also for the programmable low limits, so don't be surprised if you try to 91 set, say, fan1_min to 2900 and it finally reads 2909. 92 93 94 Fan Control 95 ----------- 96 97 PWM (pulse width modulation) values range from 0 to 255, with 0 meaning 98 that the fan is stopped, and 255 meaning that the fan goes at full speed. 99 100 Be extremely careful when changing PWM values. Low PWM values, even 101 non-zero, can stop the fan, which may cause irreversible damage to your 102 hardware if temperature increases too much. When changing PWM values, go 103 step by step and keep an eye on temperatures. 104 105 One user reported problems with PWM. Changing PWM values would break fan 106 speed readings. No explanation nor fix could be found. 107 108 109 Temperature Monitoring 110 ---------------------- 111 112 Temperatures are reported in degrees Celsius. Each temperature measured has 113 associated low, high and overtemperature limits, each of which triggers an 114 alarm when crossed. 115 116 The first two temperature channels are external. The third one (PC87366 117 only) is internal. 118 119 The PC87366 has three additional temperature channels, based on 120 thermistors (as opposed to thermal diodes for the first three temperature 121 channels). For technical reasons, these channels are held by the VLM 122 (voltage level monitor) logical device, not the TMS (temperature 123 measurement) one. As a consequence, these temperatures are exported as 124 voltages, and converted into temperatures in user-space. 125 126 Note that these three additional channels share their pins with the 127 external thermal diode channels, so you (physically) can't use them all at 128 the same time. Although it should be possible to mix the two sensor types, 129 the documents from National Semiconductor suggest that motherboard 130 manufacturers should choose one type and stick to it. So you will more 131 likely have either channels 1 to 3 (thermal diodes) or 3 to 6 (internal 132 thermal diode, and thermistors). 133 134 135 Voltage Monitoring 136 ------------------ 137 138 Voltages are reported relatively to a reference voltage, either internal or 139 external. Some of them (in7:Vsb, in8:Vdd and in10:AVdd) are divided by two 140 internally, you will have to compensate in sensors.conf. Others (in0 to in6) 141 are likely to be divided externally. The meaning of each of these inputs as 142 well as the values of the resistors used for division is left to the 143 motherboard manufacturers, so you will have to document yourself and edit 144 sensors.conf accordingly. National Semiconductor has a document with 145 recommended resistor values for some voltages, but this still leaves much 146 room for per motherboard specificities, unfortunately. Even worse, 147 motherboard manufacturers don't seem to care about National Semiconductor's 148 recommendations. 149 150 Each voltage measured has associated low and high limits, each of which 151 triggers an alarm when crossed. 152 153 When available, VID inputs are used to provide the nominal CPU Core voltage. 154 The driver will default to VRM 9.0, but this can be changed from user-space. 155 The chipsets can handle two sets of VID inputs (on dual-CPU systems), but 156 the driver will only export one for now. This may change later if there is 157 a need. 158 159 160 General Remarks 161 --------------- 162 163 If an alarm triggers, it will remain triggered until the hardware register 164 is read at least once. This means that the cause for the alarm may already 165 have disappeared! Note that all hardware registers are read whenever any 166 data is read (unless it is less than 2 seconds since the last update, in 167 which case cached values are returned instead). As a consequence, when 168 a once-only alarm triggers, it may take 2 seconds for it to show, and 2 169 more seconds for it to disappear. 170 171 Monitoring of in9 isn't enabled at lower init levels (<3) because that 172 channel measures the battery voltage (Vbat). It is a known fact that 173 repeatedly sampling the battery voltage reduces its lifetime. National 174 Semiconductor smartly designed their chipset so that in9 is sampled only 175 once every 1024 sampling cycles (that is every 34 minutes at the default 176 sampling rate), so the effect is attenuated, but still present. 177 178 179 Limitations 180 ----------- 181 182 The datasheets suggests that some values (fan mins, fan dividers) 183 shouldn't be changed once the monitoring has started, but we ignore that 184 recommendation. We'll reconsider if it actually causes trouble.