^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) .. SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) Kernel driver bt1-pvt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) =====================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) Supported chips:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Baikal-T1 PVT sensor (in SoC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) Prefix: 'bt1-pvt'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) Addresses scanned: -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) Datasheet: Provided by BAIKAL ELECTRONICS upon request and under NDA
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) Authors:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) Maxim Kaurkin <maxim.kaurkin@baikalelectronics.ru>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) Serge Semin <Sergey.Semin@baikalelectronics.ru>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) Description
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) -----------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) This driver implements support for the hardware monitoring capabilities of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) embedded into Baikal-T1 process, voltage and temperature sensors. PVT IP-core
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) consists of one temperature and four voltage sensors, which can be used to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) monitor the chip internal environment like heating, supply voltage and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) transistors performance. The driver can optionally provide the hwmon alarms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) for each sensor the PVT controller supports. The alarms functionality is made
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) compile-time configurable due to the hardware interface implementation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) peculiarity, which is connected with an ability to convert data from only one
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) sensor at a time. Additional limitation is that the controller performs the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) thresholds checking synchronously with the data conversion procedure. Due to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) these in order to have the hwmon alarms automatically detected the driver code
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) must switch from one sensor to another, read converted data and manually check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) the threshold status bits. Depending on the measurements timeout settings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) (update_interval sysfs node value) this design may cause additional burden on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) the system performance. So in case if alarms are unnecessary in your system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) design it's recommended to have them disabled to prevent the PVT IRQs being
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) periodically raised to get the data cache/alarms status up to date. By default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) in alarm-less configuration the data conversion is performed by the driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) on demand when read operation is requested via corresponding _input-file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) Temperature Monitoring
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) ----------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) Temperature is measured with 10-bit resolution and reported in millidegree
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) Celsius. The driver performs all the scaling by itself therefore reports true
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) temperatures that don't need any user-space adjustments. While the data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) translation formulae isn't linear, which gives us non-linear discreteness,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) it's close to one, but giving a bit better accuracy for higher temperatures.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) The temperature input is mapped as follows (the last column indicates the input
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) ranges)::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) temp1: CPU embedded diode -48.38C - +147.438C
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) In case if the alarms kernel config is enabled in the driver the temperature input
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) has associated min and max limits which trigger an alarm when crossed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) Voltage Monitoring
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) ------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) The voltage inputs are also sampled with 10-bit resolution and reported in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) millivolts. But in this case the data translation formulae is linear, which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) provides a constant measurements discreteness. The data scaling is also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) performed by the driver, so returning true millivolts. The voltage inputs are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) mapped as follows (the last column indicates the input ranges)::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) in0: VDD (processor core) 0.62V - 1.168V
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) in1: Low-Vt (low voltage threshold) 0.62V - 1.168V
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) in2: High-Vt (high voltage threshold) 0.62V - 1.168V
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) in3: Standard-Vt (standard voltage threshold) 0.62V - 1.168V
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) In case if the alarms config is enabled in the driver the voltage inputs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) have associated min and max limits which trigger an alarm when crossed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) Sysfs Attributes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) ----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) Following is a list of all sysfs attributes that the driver provides, their
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) permissions and a short description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) =============================== ======= =======================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) Name Perm Description
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) =============================== ======= =======================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) update_interval RW Measurements update interval per
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) sensor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) temp1_type RO Sensor type (always 1 as CPU embedded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) diode).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) temp1_label RO CPU Core Temperature sensor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) temp1_input RO Measured temperature in millidegree
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) Celsius.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) temp1_min RW Low limit for temp input.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) temp1_max RW High limit for temp input.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) temp1_min_alarm RO Temperature input alarm. Returns 1 if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) temperature input went below min limit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) 0 otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) temp1_max_alarm RO Temperature input alarm. Returns 1 if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) temperature input went above max limit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) 0 otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) temp1_offset RW Temperature offset in millidegree
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) Celsius which is added to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) temperature reading by the chip. It can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) be used to manually adjust the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) temperature measurements within 7.130
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) degrees Celsius.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) in[0-3]_label RO CPU Voltage sensor (either core or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) low/high/standard thresholds).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) in[0-3]_input RO Measured voltage in millivolts.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) in[0-3]_min RW Low limit for voltage input.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) in[0-3]_max RW High limit for voltage input.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) in[0-3]_min_alarm RO Voltage input alarm. Returns 1 if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) voltage input went below min limit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 0 otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) in[0-3]_max_alarm RO Voltage input alarm. Returns 1 if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) voltage input went above max limit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 0 otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) =============================== ======= =======================================
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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