WSL2-Linux-Kernel/Documentation/ABI/testing/sysfs-driver-w1_therm

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What: /sys/bus/w1/devices/.../alarms
Date: May 2020
Contact: Akira Shimahara <akira215corp@gmail.com>
Description:
(RW) read or write TH and TL (Temperature High an Low) alarms.
Values shall be space separated and in the device range
(typical -55 degC to 125 degC), if not values will be trimmed
to device min/max capabilities. Values are integer as they are
stored in a 8bit register in the device. Lowest value is
automatically put to TL. Once set, alarms could be search at
master level, refer to Documentation/w1/w1-generic.rst for
detailed information
Users: any user space application which wants to communicate with
w1_term device
What: /sys/bus/w1/devices/.../eeprom_cmd
Date: May 2020
Contact: Akira Shimahara <akira215corp@gmail.com>
Description:
(WO) writing that file will either trigger a save of the
device data to its embedded EEPROM, either restore data
embedded in device EEPROM. Be aware that devices support
limited EEPROM writing cycles (typical 50k)
* 'save': save device RAM to EEPROM
* 'restore': restore EEPROM data in device RAM
Users: any user space application which wants to communicate with
w1_term device
What: /sys/bus/w1/devices/.../ext_power
Date: May 2020
Contact: Akira Shimahara <akira215corp@gmail.com>
Description:
(RO) return the power status by asking the device
* '0': device parasite powered
* '1': device externally powered
* '-xx': xx is kernel error when reading power status
Users: any user space application which wants to communicate with
w1_term device
w1_therm: adding resolution sysfs entry Adding resolution sysfs entry (RW) to get or set the device resolution Write values are managed as follow: * '9..12': resolution to set in bit * Anything else: do nothing Read values are : * '9..12': device resolution in bit * '-xx': xx is kernel error when reading the resolution Only supported devices will show the sysfs entry. A new family has been created for DS18S20 devices as they do not implement resolution feature. The resolution of each device is check when the device is discover by the bus master, in 'w1_therm_add_slave(struct w1_slave *)'. The status is stored in the device structure w1_therm_family_data so that the driver always knows the resolution of each device, which could be used later to determine the required conversion duration (resolution dependent). The resolution is re evaluate each time a user read or write the sysfs entry. To avoid looping through the w1_therm_families at run time, the pointer 'specific_functions' is set up to the correct 'w1_therm_family_converter' when the slave is added (which mean when it is discovered by the master). This initialization is done by a helper function 'device_family(struct w1_slave *sl)', and a dedicated macro 'SLAVE_SPECIFIC_FUNC(sl)' allow the access to the specific function of the slave device. 'read_scratchpad' and 'write_scratchpad' are the hardware functions to access the device RAM, as per protocol specification. It cancel the former 'precision' functions, which was only set and never read (so not stored in the device struct). Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203708.410649-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11 23:37:08 +03:00
What: /sys/bus/w1/devices/.../resolution
Date: May 2020
Contact: Akira Shimahara <akira215corp@gmail.com>
Description:
(RW) get or set the device resolution (on supported devices,
if not, this entry is not present). Note that the resolution
will be changed only in device RAM, so it will be cleared when
power is lost. Trigger a 'save' to EEPROM command to keep
values after power-on. Read or write are :
* '9..14': device resolution in bit
or resolution to set in bit
w1_therm: adding resolution sysfs entry Adding resolution sysfs entry (RW) to get or set the device resolution Write values are managed as follow: * '9..12': resolution to set in bit * Anything else: do nothing Read values are : * '9..12': device resolution in bit * '-xx': xx is kernel error when reading the resolution Only supported devices will show the sysfs entry. A new family has been created for DS18S20 devices as they do not implement resolution feature. The resolution of each device is check when the device is discover by the bus master, in 'w1_therm_add_slave(struct w1_slave *)'. The status is stored in the device structure w1_therm_family_data so that the driver always knows the resolution of each device, which could be used later to determine the required conversion duration (resolution dependent). The resolution is re evaluate each time a user read or write the sysfs entry. To avoid looping through the w1_therm_families at run time, the pointer 'specific_functions' is set up to the correct 'w1_therm_family_converter' when the slave is added (which mean when it is discovered by the master). This initialization is done by a helper function 'device_family(struct w1_slave *sl)', and a dedicated macro 'SLAVE_SPECIFIC_FUNC(sl)' allow the access to the specific function of the slave device. 'read_scratchpad' and 'write_scratchpad' are the hardware functions to access the device RAM, as per protocol specification. It cancel the former 'precision' functions, which was only set and never read (so not stored in the device struct). Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203708.410649-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11 23:37:08 +03:00
* '-xx': xx is kernel error when reading the resolution
* Anything else: do nothing
w1: w1_therm: Add sysfs entries to control conversion time and driver features The conversion time of common DS18B20 clones deviates from datasheet specs. Allow adjustment and automatic measure of the conversion time. Add 'conv_time' sysfs attribute: *read*: Current conversion time in milliseconds. *write*: '0': Set default conversion time. '1': Measure and set the conversion time. Make a single temperature conversion, poll and measure an actual value. Measured value is increased by 20% for temperature drift. A new conversion time is returned by reading the same attribute. other positive value: Set the conversion time in milliseconds. The setting is active until a resolution change. Then it is reset to default conversion time for a new resolution. Add 'features' sysfs attribute to control optional driver settings per device. Bit masks to read/write (logical OR): 1: Enable check for conversion success. If byte 6 of scratchpad memory is 0xC after conversion, and temperature reads 85.00 (powerup value) or 127.94 (insufficient power) - return a conversion error. 2: Enable poll for conversion completion. Generate read cycles after the conversion start and wait for 1's. In parasite power mode this feature is not available. There are some clones of DS18B20 with fixed 12 bit resolution. Make the driver verify the resolution by reading back the device after resolution change. Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Link: https://lore.kernel.org/r/20200904160004.87710-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-04 19:00:03 +03:00
Some DS18B20 clones are fixed in 12-bit resolution, so the
actual resolution is read back from the chip and verified. Error
is reported if the results differ.
w1_therm: adding resolution sysfs entry Adding resolution sysfs entry (RW) to get or set the device resolution Write values are managed as follow: * '9..12': resolution to set in bit * Anything else: do nothing Read values are : * '9..12': device resolution in bit * '-xx': xx is kernel error when reading the resolution Only supported devices will show the sysfs entry. A new family has been created for DS18S20 devices as they do not implement resolution feature. The resolution of each device is check when the device is discover by the bus master, in 'w1_therm_add_slave(struct w1_slave *)'. The status is stored in the device structure w1_therm_family_data so that the driver always knows the resolution of each device, which could be used later to determine the required conversion duration (resolution dependent). The resolution is re evaluate each time a user read or write the sysfs entry. To avoid looping through the w1_therm_families at run time, the pointer 'specific_functions' is set up to the correct 'w1_therm_family_converter' when the slave is added (which mean when it is discovered by the master). This initialization is done by a helper function 'device_family(struct w1_slave *sl)', and a dedicated macro 'SLAVE_SPECIFIC_FUNC(sl)' allow the access to the specific function of the slave device. 'read_scratchpad' and 'write_scratchpad' are the hardware functions to access the device RAM, as per protocol specification. It cancel the former 'precision' functions, which was only set and never read (so not stored in the device struct). Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203708.410649-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11 23:37:08 +03:00
Users: any user space application which wants to communicate with
w1_term device
What: /sys/bus/w1/devices/.../temperature
Date: May 2020
Contact: Akira Shimahara <akira215corp@gmail.com>
Description:
(RO) return the temperature in 1/1000 degC.
w1_therm: adding bulk read support to trigger multiple conversion on bus Adding bulk read support: Sending a 'trigger' command in the dedicated sysfs entry of bus master device send a conversion command for all the slaves on the bus. The sysfs entry is added as soon as at least one device supporting this feature is detected on the bus. The behavior of the sysfs reading temperature on the device is as follow: * If no bulk read pending, trigger a conversion on the device, wait for the conversion to be done, read the temperature in device RAM * If a bulk read has been trigger, access directly the device RAM This behavior is the same on the 2 sysfs entries ('temperature' and 'w1_slave'). Reading the therm_bulk_read sysfs give the status of bulk operations: * '-1': conversion in progress on at least 1 sensor * '1': conversion complete but at least one sensor has not been read yet * '0': no bulk operation. Reading temperature on ecah device will trigger a conversion As not all devices support bulk read feature, it has been added in device family structure. The attribute is set at master level as soon as a supporting device is discover. It is removed when the last supported device leave the bus. The count of supported device is kept with the static counter bulk_read_device_counter. A strong pull up is apply on the line if at least one device required it. The duration of the pull up is the max time required by a device on the line, which depends on the resolution settings of each device. The strong pull up could be adjust with the a module parameter. Updating documentation in Documentation/ABI/testing/sysfs-driver-w1_therm and Documentation/w1/slaves/w1_therm.rst accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203820.411483-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11 23:38:20 +03:00
* If a bulk read has been triggered, it will directly
return the temperature computed when the bulk read
occurred, if available. If not yet available, nothing
is returned (a debug kernel message is sent), you
should retry later on.
w1_therm: adding bulk read support to trigger multiple conversion on bus Adding bulk read support: Sending a 'trigger' command in the dedicated sysfs entry of bus master device send a conversion command for all the slaves on the bus. The sysfs entry is added as soon as at least one device supporting this feature is detected on the bus. The behavior of the sysfs reading temperature on the device is as follow: * If no bulk read pending, trigger a conversion on the device, wait for the conversion to be done, read the temperature in device RAM * If a bulk read has been trigger, access directly the device RAM This behavior is the same on the 2 sysfs entries ('temperature' and 'w1_slave'). Reading the therm_bulk_read sysfs give the status of bulk operations: * '-1': conversion in progress on at least 1 sensor * '1': conversion complete but at least one sensor has not been read yet * '0': no bulk operation. Reading temperature on ecah device will trigger a conversion As not all devices support bulk read feature, it has been added in device family structure. The attribute is set at master level as soon as a supporting device is discover. It is removed when the last supported device leave the bus. The count of supported device is kept with the static counter bulk_read_device_counter. A strong pull up is apply on the line if at least one device required it. The duration of the pull up is the max time required by a device on the line, which depends on the resolution settings of each device. The strong pull up could be adjust with the a module parameter. Updating documentation in Documentation/ABI/testing/sysfs-driver-w1_therm and Documentation/w1/slaves/w1_therm.rst accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203820.411483-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11 23:38:20 +03:00
* If no bulk read has been triggered, it will trigger
a conversion and send the result. Note that the
conversion duration depend on the resolution (if
device support this feature). It takes 94ms in 9bits
resolution, 750ms for 12bits.
Users: any user space application which wants to communicate with
w1_term device
What: /sys/bus/w1/devices/.../w1_slave
Date: May 2020
Contact: Akira Shimahara <akira215corp@gmail.com>
Description:
(RW) return the temperature in 1/1000 degC.
*read*: return 2 lines with the hexa output data sent on the
bus, return the CRC check and temperature in 1/1000 degC
*write*:
* '0' : save the 2 or 3 bytes to the device EEPROM
(i.e. TH, TL and config register)
* '9..14' : set the device resolution in RAM
(if supported)
* Anything else: do nothing
refer to Documentation/w1/slaves/w1_therm.rst for detailed
information.
Users: any user space application which wants to communicate with
w1_therm: adding bulk read support to trigger multiple conversion on bus Adding bulk read support: Sending a 'trigger' command in the dedicated sysfs entry of bus master device send a conversion command for all the slaves on the bus. The sysfs entry is added as soon as at least one device supporting this feature is detected on the bus. The behavior of the sysfs reading temperature on the device is as follow: * If no bulk read pending, trigger a conversion on the device, wait for the conversion to be done, read the temperature in device RAM * If a bulk read has been trigger, access directly the device RAM This behavior is the same on the 2 sysfs entries ('temperature' and 'w1_slave'). Reading the therm_bulk_read sysfs give the status of bulk operations: * '-1': conversion in progress on at least 1 sensor * '1': conversion complete but at least one sensor has not been read yet * '0': no bulk operation. Reading temperature on ecah device will trigger a conversion As not all devices support bulk read feature, it has been added in device family structure. The attribute is set at master level as soon as a supporting device is discover. It is removed when the last supported device leave the bus. The count of supported device is kept with the static counter bulk_read_device_counter. A strong pull up is apply on the line if at least one device required it. The duration of the pull up is the max time required by a device on the line, which depends on the resolution settings of each device. The strong pull up could be adjust with the a module parameter. Updating documentation in Documentation/ABI/testing/sysfs-driver-w1_therm and Documentation/w1/slaves/w1_therm.rst accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203820.411483-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11 23:38:20 +03:00
w1_term device
What: /sys/bus/w1/devices/w1_bus_masterXX/therm_bulk_read
Date: May 2020
Contact: Akira Shimahara <akira215corp@gmail.com>
Description:
(RW) trigger a bulk read conversion. read the status
w1_therm: adding bulk read support to trigger multiple conversion on bus Adding bulk read support: Sending a 'trigger' command in the dedicated sysfs entry of bus master device send a conversion command for all the slaves on the bus. The sysfs entry is added as soon as at least one device supporting this feature is detected on the bus. The behavior of the sysfs reading temperature on the device is as follow: * If no bulk read pending, trigger a conversion on the device, wait for the conversion to be done, read the temperature in device RAM * If a bulk read has been trigger, access directly the device RAM This behavior is the same on the 2 sysfs entries ('temperature' and 'w1_slave'). Reading the therm_bulk_read sysfs give the status of bulk operations: * '-1': conversion in progress on at least 1 sensor * '1': conversion complete but at least one sensor has not been read yet * '0': no bulk operation. Reading temperature on ecah device will trigger a conversion As not all devices support bulk read feature, it has been added in device family structure. The attribute is set at master level as soon as a supporting device is discover. It is removed when the last supported device leave the bus. The count of supported device is kept with the static counter bulk_read_device_counter. A strong pull up is apply on the line if at least one device required it. The duration of the pull up is the max time required by a device on the line, which depends on the resolution settings of each device. The strong pull up could be adjust with the a module parameter. Updating documentation in Documentation/ABI/testing/sysfs-driver-w1_therm and Documentation/w1/slaves/w1_therm.rst accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203820.411483-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11 23:38:20 +03:00
*read*:
* '-1':
conversion in progress on at least 1 sensor
* '1' :
conversion complete but at least one sensor
w1_therm: adding bulk read support to trigger multiple conversion on bus Adding bulk read support: Sending a 'trigger' command in the dedicated sysfs entry of bus master device send a conversion command for all the slaves on the bus. The sysfs entry is added as soon as at least one device supporting this feature is detected on the bus. The behavior of the sysfs reading temperature on the device is as follow: * If no bulk read pending, trigger a conversion on the device, wait for the conversion to be done, read the temperature in device RAM * If a bulk read has been trigger, access directly the device RAM This behavior is the same on the 2 sysfs entries ('temperature' and 'w1_slave'). Reading the therm_bulk_read sysfs give the status of bulk operations: * '-1': conversion in progress on at least 1 sensor * '1': conversion complete but at least one sensor has not been read yet * '0': no bulk operation. Reading temperature on ecah device will trigger a conversion As not all devices support bulk read feature, it has been added in device family structure. The attribute is set at master level as soon as a supporting device is discover. It is removed when the last supported device leave the bus. The count of supported device is kept with the static counter bulk_read_device_counter. A strong pull up is apply on the line if at least one device required it. The duration of the pull up is the max time required by a device on the line, which depends on the resolution settings of each device. The strong pull up could be adjust with the a module parameter. Updating documentation in Documentation/ABI/testing/sysfs-driver-w1_therm and Documentation/w1/slaves/w1_therm.rst accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203820.411483-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11 23:38:20 +03:00
value has not been read yet
* '0' :
no bulk operation. Reading temperature will
w1_therm: adding bulk read support to trigger multiple conversion on bus Adding bulk read support: Sending a 'trigger' command in the dedicated sysfs entry of bus master device send a conversion command for all the slaves on the bus. The sysfs entry is added as soon as at least one device supporting this feature is detected on the bus. The behavior of the sysfs reading temperature on the device is as follow: * If no bulk read pending, trigger a conversion on the device, wait for the conversion to be done, read the temperature in device RAM * If a bulk read has been trigger, access directly the device RAM This behavior is the same on the 2 sysfs entries ('temperature' and 'w1_slave'). Reading the therm_bulk_read sysfs give the status of bulk operations: * '-1': conversion in progress on at least 1 sensor * '1': conversion complete but at least one sensor has not been read yet * '0': no bulk operation. Reading temperature on ecah device will trigger a conversion As not all devices support bulk read feature, it has been added in device family structure. The attribute is set at master level as soon as a supporting device is discover. It is removed when the last supported device leave the bus. The count of supported device is kept with the static counter bulk_read_device_counter. A strong pull up is apply on the line if at least one device required it. The duration of the pull up is the max time required by a device on the line, which depends on the resolution settings of each device. The strong pull up could be adjust with the a module parameter. Updating documentation in Documentation/ABI/testing/sysfs-driver-w1_therm and Documentation/w1/slaves/w1_therm.rst accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203820.411483-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11 23:38:20 +03:00
trigger a conversion on each device
*write*:
'trigger': trigger a bulk read on all supporting
w1_therm: adding bulk read support to trigger multiple conversion on bus Adding bulk read support: Sending a 'trigger' command in the dedicated sysfs entry of bus master device send a conversion command for all the slaves on the bus. The sysfs entry is added as soon as at least one device supporting this feature is detected on the bus. The behavior of the sysfs reading temperature on the device is as follow: * If no bulk read pending, trigger a conversion on the device, wait for the conversion to be done, read the temperature in device RAM * If a bulk read has been trigger, access directly the device RAM This behavior is the same on the 2 sysfs entries ('temperature' and 'w1_slave'). Reading the therm_bulk_read sysfs give the status of bulk operations: * '-1': conversion in progress on at least 1 sensor * '1': conversion complete but at least one sensor has not been read yet * '0': no bulk operation. Reading temperature on ecah device will trigger a conversion As not all devices support bulk read feature, it has been added in device family structure. The attribute is set at master level as soon as a supporting device is discover. It is removed when the last supported device leave the bus. The count of supported device is kept with the static counter bulk_read_device_counter. A strong pull up is apply on the line if at least one device required it. The duration of the pull up is the max time required by a device on the line, which depends on the resolution settings of each device. The strong pull up could be adjust with the a module parameter. Updating documentation in Documentation/ABI/testing/sysfs-driver-w1_therm and Documentation/w1/slaves/w1_therm.rst accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203820.411483-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11 23:38:20 +03:00
devices on the bus
w1_therm: adding bulk read support to trigger multiple conversion on bus Adding bulk read support: Sending a 'trigger' command in the dedicated sysfs entry of bus master device send a conversion command for all the slaves on the bus. The sysfs entry is added as soon as at least one device supporting this feature is detected on the bus. The behavior of the sysfs reading temperature on the device is as follow: * If no bulk read pending, trigger a conversion on the device, wait for the conversion to be done, read the temperature in device RAM * If a bulk read has been trigger, access directly the device RAM This behavior is the same on the 2 sysfs entries ('temperature' and 'w1_slave'). Reading the therm_bulk_read sysfs give the status of bulk operations: * '-1': conversion in progress on at least 1 sensor * '1': conversion complete but at least one sensor has not been read yet * '0': no bulk operation. Reading temperature on ecah device will trigger a conversion As not all devices support bulk read feature, it has been added in device family structure. The attribute is set at master level as soon as a supporting device is discover. It is removed when the last supported device leave the bus. The count of supported device is kept with the static counter bulk_read_device_counter. A strong pull up is apply on the line if at least one device required it. The duration of the pull up is the max time required by a device on the line, which depends on the resolution settings of each device. The strong pull up could be adjust with the a module parameter. Updating documentation in Documentation/ABI/testing/sysfs-driver-w1_therm and Documentation/w1/slaves/w1_therm.rst accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203820.411483-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11 23:38:20 +03:00
Note that if a bulk read is sent but one sensor is not read
immediately, the next access to temperature on this device
will return the temperature measured at the time of issue
of the bulk read command (not the current temperature).
Users: any user space application which wants to communicate with
w1_term device
w1: w1_therm: Add sysfs entries to control conversion time and driver features The conversion time of common DS18B20 clones deviates from datasheet specs. Allow adjustment and automatic measure of the conversion time. Add 'conv_time' sysfs attribute: *read*: Current conversion time in milliseconds. *write*: '0': Set default conversion time. '1': Measure and set the conversion time. Make a single temperature conversion, poll and measure an actual value. Measured value is increased by 20% for temperature drift. A new conversion time is returned by reading the same attribute. other positive value: Set the conversion time in milliseconds. The setting is active until a resolution change. Then it is reset to default conversion time for a new resolution. Add 'features' sysfs attribute to control optional driver settings per device. Bit masks to read/write (logical OR): 1: Enable check for conversion success. If byte 6 of scratchpad memory is 0xC after conversion, and temperature reads 85.00 (powerup value) or 127.94 (insufficient power) - return a conversion error. 2: Enable poll for conversion completion. Generate read cycles after the conversion start and wait for 1's. In parasite power mode this feature is not available. There are some clones of DS18B20 with fixed 12 bit resolution. Make the driver verify the resolution by reading back the device after resolution change. Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Link: https://lore.kernel.org/r/20200904160004.87710-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-04 19:00:03 +03:00
What: /sys/bus/w1/devices/.../conv_time
Date: July 2020
Contact: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
Description:
(RW) Get, set, or measure a temperature conversion time. The
setting remains active until a resolution change. Then it is
reset to default (datasheet) conversion time for a new
resolution.
*read*:
Actual conversion time in milliseconds.
*write*:
* '0':
Set the default conversion time from the datasheet.
* '1':
Measure and set the conversion time. Make a single
w1: w1_therm: Add sysfs entries to control conversion time and driver features The conversion time of common DS18B20 clones deviates from datasheet specs. Allow adjustment and automatic measure of the conversion time. Add 'conv_time' sysfs attribute: *read*: Current conversion time in milliseconds. *write*: '0': Set default conversion time. '1': Measure and set the conversion time. Make a single temperature conversion, poll and measure an actual value. Measured value is increased by 20% for temperature drift. A new conversion time is returned by reading the same attribute. other positive value: Set the conversion time in milliseconds. The setting is active until a resolution change. Then it is reset to default conversion time for a new resolution. Add 'features' sysfs attribute to control optional driver settings per device. Bit masks to read/write (logical OR): 1: Enable check for conversion success. If byte 6 of scratchpad memory is 0xC after conversion, and temperature reads 85.00 (powerup value) or 127.94 (insufficient power) - return a conversion error. 2: Enable poll for conversion completion. Generate read cycles after the conversion start and wait for 1's. In parasite power mode this feature is not available. There are some clones of DS18B20 with fixed 12 bit resolution. Make the driver verify the resolution by reading back the device after resolution change. Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Link: https://lore.kernel.org/r/20200904160004.87710-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-04 19:00:03 +03:00
temperature conversion, measure an actual value.
Increase it by 20% for temperature range. A new
conversion time can be obtained by reading this
same attribute.
* other positive value:
w1: w1_therm: Add sysfs entries to control conversion time and driver features The conversion time of common DS18B20 clones deviates from datasheet specs. Allow adjustment and automatic measure of the conversion time. Add 'conv_time' sysfs attribute: *read*: Current conversion time in milliseconds. *write*: '0': Set default conversion time. '1': Measure and set the conversion time. Make a single temperature conversion, poll and measure an actual value. Measured value is increased by 20% for temperature drift. A new conversion time is returned by reading the same attribute. other positive value: Set the conversion time in milliseconds. The setting is active until a resolution change. Then it is reset to default conversion time for a new resolution. Add 'features' sysfs attribute to control optional driver settings per device. Bit masks to read/write (logical OR): 1: Enable check for conversion success. If byte 6 of scratchpad memory is 0xC after conversion, and temperature reads 85.00 (powerup value) or 127.94 (insufficient power) - return a conversion error. 2: Enable poll for conversion completion. Generate read cycles after the conversion start and wait for 1's. In parasite power mode this feature is not available. There are some clones of DS18B20 with fixed 12 bit resolution. Make the driver verify the resolution by reading back the device after resolution change. Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Link: https://lore.kernel.org/r/20200904160004.87710-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-04 19:00:03 +03:00
Set the conversion time in milliseconds.
Users: An application using the w1_term device
What: /sys/bus/w1/devices/.../features
Date: July 2020
Contact: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
Description:
(RW) Control optional driver settings.
Bit masks to read/write (bitwise OR):
w1: w1_therm: Add sysfs entries to control conversion time and driver features The conversion time of common DS18B20 clones deviates from datasheet specs. Allow adjustment and automatic measure of the conversion time. Add 'conv_time' sysfs attribute: *read*: Current conversion time in milliseconds. *write*: '0': Set default conversion time. '1': Measure and set the conversion time. Make a single temperature conversion, poll and measure an actual value. Measured value is increased by 20% for temperature drift. A new conversion time is returned by reading the same attribute. other positive value: Set the conversion time in milliseconds. The setting is active until a resolution change. Then it is reset to default conversion time for a new resolution. Add 'features' sysfs attribute to control optional driver settings per device. Bit masks to read/write (logical OR): 1: Enable check for conversion success. If byte 6 of scratchpad memory is 0xC after conversion, and temperature reads 85.00 (powerup value) or 127.94 (insufficient power) - return a conversion error. 2: Enable poll for conversion completion. Generate read cycles after the conversion start and wait for 1's. In parasite power mode this feature is not available. There are some clones of DS18B20 with fixed 12 bit resolution. Make the driver verify the resolution by reading back the device after resolution change. Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Link: https://lore.kernel.org/r/20200904160004.87710-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-04 19:00:03 +03:00
== ============================================================
1 Enable check for conversion success. If byte 6 of
w1: w1_therm: Add sysfs entries to control conversion time and driver features The conversion time of common DS18B20 clones deviates from datasheet specs. Allow adjustment and automatic measure of the conversion time. Add 'conv_time' sysfs attribute: *read*: Current conversion time in milliseconds. *write*: '0': Set default conversion time. '1': Measure and set the conversion time. Make a single temperature conversion, poll and measure an actual value. Measured value is increased by 20% for temperature drift. A new conversion time is returned by reading the same attribute. other positive value: Set the conversion time in milliseconds. The setting is active until a resolution change. Then it is reset to default conversion time for a new resolution. Add 'features' sysfs attribute to control optional driver settings per device. Bit masks to read/write (logical OR): 1: Enable check for conversion success. If byte 6 of scratchpad memory is 0xC after conversion, and temperature reads 85.00 (powerup value) or 127.94 (insufficient power) - return a conversion error. 2: Enable poll for conversion completion. Generate read cycles after the conversion start and wait for 1's. In parasite power mode this feature is not available. There are some clones of DS18B20 with fixed 12 bit resolution. Make the driver verify the resolution by reading back the device after resolution change. Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Link: https://lore.kernel.org/r/20200904160004.87710-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-04 19:00:03 +03:00
scratchpad memory is 0xC after conversion, and
temperature reads 85.00 (powerup value) or 127.94
(insufficient power) - return a conversion error.
2 Enable poll for conversion completion. Generate read cycles
w1: w1_therm: Add sysfs entries to control conversion time and driver features The conversion time of common DS18B20 clones deviates from datasheet specs. Allow adjustment and automatic measure of the conversion time. Add 'conv_time' sysfs attribute: *read*: Current conversion time in milliseconds. *write*: '0': Set default conversion time. '1': Measure and set the conversion time. Make a single temperature conversion, poll and measure an actual value. Measured value is increased by 20% for temperature drift. A new conversion time is returned by reading the same attribute. other positive value: Set the conversion time in milliseconds. The setting is active until a resolution change. Then it is reset to default conversion time for a new resolution. Add 'features' sysfs attribute to control optional driver settings per device. Bit masks to read/write (logical OR): 1: Enable check for conversion success. If byte 6 of scratchpad memory is 0xC after conversion, and temperature reads 85.00 (powerup value) or 127.94 (insufficient power) - return a conversion error. 2: Enable poll for conversion completion. Generate read cycles after the conversion start and wait for 1's. In parasite power mode this feature is not available. There are some clones of DS18B20 with fixed 12 bit resolution. Make the driver verify the resolution by reading back the device after resolution change. Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Link: https://lore.kernel.org/r/20200904160004.87710-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-04 19:00:03 +03:00
after the conversion start and wait for 1's. In parasite
power mode this feature is not available.
== ============================================================
*read*:
Currently selected features.
w1: w1_therm: Add sysfs entries to control conversion time and driver features The conversion time of common DS18B20 clones deviates from datasheet specs. Allow adjustment and automatic measure of the conversion time. Add 'conv_time' sysfs attribute: *read*: Current conversion time in milliseconds. *write*: '0': Set default conversion time. '1': Measure and set the conversion time. Make a single temperature conversion, poll and measure an actual value. Measured value is increased by 20% for temperature drift. A new conversion time is returned by reading the same attribute. other positive value: Set the conversion time in milliseconds. The setting is active until a resolution change. Then it is reset to default conversion time for a new resolution. Add 'features' sysfs attribute to control optional driver settings per device. Bit masks to read/write (logical OR): 1: Enable check for conversion success. If byte 6 of scratchpad memory is 0xC after conversion, and temperature reads 85.00 (powerup value) or 127.94 (insufficient power) - return a conversion error. 2: Enable poll for conversion completion. Generate read cycles after the conversion start and wait for 1's. In parasite power mode this feature is not available. There are some clones of DS18B20 with fixed 12 bit resolution. Make the driver verify the resolution by reading back the device after resolution change. Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Link: https://lore.kernel.org/r/20200904160004.87710-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-04 19:00:03 +03:00
*write*:
Select features.
w1: w1_therm: Add sysfs entries to control conversion time and driver features The conversion time of common DS18B20 clones deviates from datasheet specs. Allow adjustment and automatic measure of the conversion time. Add 'conv_time' sysfs attribute: *read*: Current conversion time in milliseconds. *write*: '0': Set default conversion time. '1': Measure and set the conversion time. Make a single temperature conversion, poll and measure an actual value. Measured value is increased by 20% for temperature drift. A new conversion time is returned by reading the same attribute. other positive value: Set the conversion time in milliseconds. The setting is active until a resolution change. Then it is reset to default conversion time for a new resolution. Add 'features' sysfs attribute to control optional driver settings per device. Bit masks to read/write (logical OR): 1: Enable check for conversion success. If byte 6 of scratchpad memory is 0xC after conversion, and temperature reads 85.00 (powerup value) or 127.94 (insufficient power) - return a conversion error. 2: Enable poll for conversion completion. Generate read cycles after the conversion start and wait for 1's. In parasite power mode this feature is not available. There are some clones of DS18B20 with fixed 12 bit resolution. Make the driver verify the resolution by reading back the device after resolution change. Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Link: https://lore.kernel.org/r/20200904160004.87710-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-04 19:00:03 +03:00
Users: An application using the w1_term device