w1: w1_therm: Rename conflicting sysfs attribute 'eeprom' to 'eeprom_cmd'

Duplicate attribute 'eeprom' is defined in:
1) Documentation/ABI/testing/sysfs-driver-w1_therm
2) Documentation/ABI/stable/s

w1: w1_therm: Rename conflicting sysfs attribute 'eeprom' to 'eeprom_cmd'

Duplicate attribute 'eeprom' is defined in:
1) Documentation/ABI/testing/sysfs-driver-w1_therm
2) Documentation/ABI/stable/sysfs-driver-w1_ds28e04

Both drivers define an attribute: /sys/bus/w1/devices/.../eeprom
with conflicting behavior.

Fix by renaming the newer one in w1_therm.c to 'eeprom_cmd'.

Reported-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/lkml/20201029152845.6bbb39ce@coco.lan/
Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
Link: https://lore.kernel.org/r/20201112064931.8471-1-ivan.zaentsev@wirenboard.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

docs: ABI: fix syntax to be parsed using ReST notation

There are a number of new changes at the ABI files that cause
them to produce warnings when generating ABI output.

Fix them.

Acked-by: Jonath

docs: ABI: fix syntax to be parsed using ReST notation

There are a number of new changes at the ABI files that cause
them to produce warnings when generating ABI output.

Fix them.

Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/55a89f423cf122982c462d257722e44d6ece4b36.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

docs: w1: w1_therm: Fix broken xref, mistakes, clarify text

sysfs attribute names are mixed with the same normal text terms.
Use ReST to distinguish.

Fix typos and mistakes.

Reported-by: Mauro Car

docs: w1: w1_therm: Fix broken xref, mistakes, clarify text

sysfs attribute names are mixed with the same normal text terms.
Use ReST to distinguish.

Fix typos and mistakes.

Reported-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
Link: https://lore.kernel.org/r/20201008054259.5461-1-ivan.zaentsev@wirenboard.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

w1: w1_therm: Add support for GXCAS GX20MH01 device.

GX20MH01 device shares family number 0x28 with DS18B20. The device
is generally compatible with DS18B20. Added are the lowest 2^-5, 2^-6
temperat

w1: w1_therm: Add support for GXCAS GX20MH01 device.

GX20MH01 device shares family number 0x28 with DS18B20. The device
is generally compatible with DS18B20. Added are the lowest 2^-5, 2^-6
temperature bits in Config register; R2 bit in Config register
enabling 13 and 14 bit resolutions. It is powered up in 14 bit mode.

Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
Link: https://lore.kernel.org/r/20200904160004.87710-2-ivan.zaentsev@wirenboard.ru
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

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 t

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>

show more ...

docs: ABI: fix a typo when pointing to w1-generic.rst

There's a typo there:

w1_generic.rst -> w1-generic.rst

Causing the document reference to point to the wrong place.

Fixes: e2c94d6f5720 ("w1_

docs: ABI: fix a typo when pointing to w1-generic.rst

There's a typo there:

w1_generic.rst -> w1-generic.rst

Causing the document reference to point to the wrong place.

Fixes: e2c94d6f5720 ("w1_therm: adding alarm sysfs entry")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/66b47dd879e8ae38b6db6d2f38780e00a29fc086.1592895969.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

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 com

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>

show more ...

w1_therm: adding alarm sysfs entry

Adding device alarms settings by a dedicated sysfs entry alarms (RW):
read or write TH and TL in the device RAM. Checking devices in alarm
state could be performed

w1_therm: adding alarm sysfs entry

Adding device alarms settings by a dedicated sysfs entry alarms (RW):
read or write TH and TL in the device RAM. Checking devices in alarm
state could be performed using the master search command.

As alarms temperature level are store in a 8 bit register on the device
and are signed values, a safe cast shall be performed using the min and
max temperature that device are able to measure. This is done by
int_to_short inline function.

A 'write_data' field is added in the device structure, to bind the
correct writing function, as some devices may have 2 or 3 bytes RAM.

Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly.

Signed-off-by: Akira Shimahara <akira215corp@gmail.com>
Link: https://lore.kernel.org/r/20200511203801.411253-1-akira215corp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

w1_therm: optimizing temperature read timings

Optimizing temperature reading by reducing waiting conversion time
according to device resolution settings, as per device specification.
This is device

w1_therm: optimizing temperature read timings

Optimizing temperature reading by reducing waiting conversion time
according to device resolution settings, as per device specification.
This is device dependent as not all the devices supports resolution
setting, so it has been added in device family structures.

The process to read the temperature on the device has been adapted in a
new function 'convert_t()', which replace the former 'read_therm()', is
introduce to deal with this timing. Strong pull up is also applied during
the required time, according to device power status needs and
'strong_pullup' module parameter.

'temperature_from_RAM()' function is introduced to get the correct
temperature computation (device dependent) from device RAM data.

An new sysfs entry has been added to ouptut only temperature. The old
entry w1_slave has been kept for compatibility, without changing its
output format.

Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly.

Signed-off-by: Akira Shimahara <akira215corp@gmail.com>
Link: https://lore.kernel.org/r/20200511203742.411039-1-akira215corp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

w1_therm: adding eeprom sysfs entry

The driver implement 2 hardware functions to access device RAM:
* copy_scratchpad
* recall_scratchpad
They act according to device specifications.

As EEPROM op

w1_therm: adding eeprom sysfs entry

The driver implement 2 hardware functions to access device RAM:
* copy_scratchpad
* recall_scratchpad
They act according to device specifications.

As EEPROM operations are not device dependent (all w1_therm can perform
EEPROM read/write operation following the same protocol), it is removed
from device families structures.

Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly.

Signed-off-by: Akira Shimahara <akira215corp@gmail.com>
Link: https://lore.kernel.org/r/20200511203725.410844-1-akira215corp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

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 el

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>

show more ...

w1_therm: adding ext_power sysfs entry

Adding ext_power sysfs entry (RO). Return the power status of the device:
- 0: device parasite powered
- 1: device externally powered
- xx: xx is kernel err

w1_therm: adding ext_power sysfs entry

Adding ext_power sysfs entry (RO). Return the power status of the device:
- 0: device parasite powered
- 1: device externally powered
- xx: xx is kernel error

The power status 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 power state of each device, which could
be used later to determine the required strong pull up to apply on the
line.

The power status is re evaluate each time the sysfs ext_power read by
a user.

The hardware function 'read_powermode(struct w1_slave *sl)' act just as
per device specifications, sending W1_READ_PSUPPLY command on the bus,
and issue a read time slot, reading only one bit.

A helper function 'bool bus_mutex_lock(struct mutex *lock)' is introduced.
It try to aquire the bus mutex several times (W1_THERM_MAX_TRY), waiting
W1_THERM_RETRY_DELAY between two attempt.

Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly.

Signed-off-by: Akira Shimahara <akira215corp@gmail.com>
Link: https://lore.kernel.org/r/20200511203650.410439-1-akira215corp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

w1_therm: adding sysfs-driver-w1_therm doc

Adding a sysfs-driver-w1_therm documentation file in
Documentation/ABI/testing. It describe the onlys sysfs entry of w1_therm
module, based on Documentatio

w1_therm: adding sysfs-driver-w1_therm doc

Adding a sysfs-driver-w1_therm documentation file in
Documentation/ABI/testing. It describe the onlys sysfs entry of w1_therm
module, based on Documentation/w1/slaves/w1_therm.rst

Signed-off-by: Akira Shimahara <akira215corp@gmail.com>
Link: https://lore.kernel.org/r/20200511203631.410227-1-akira215corp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

docs: ABI: fix syntax to be parsed using ReST notation

There are a number of new changes at the ABI files that cause
them to produce warnings when generating ABI output.

Fix the

docs: ABI: fix syntax to be parsed using ReST notation

There are a number of new changes at the ABI files that cause
them to produce warnings when generating ABI output.

Fix them.

Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/55a89f423cf122982c462d257722e44d6ece4b36.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

docs: w1: w1_therm: Fix broken xref, mistakes, clarify text

sysfs attribute names are mixed with the same normal text terms.
Use ReST to distinguish.

Fix typos and mistakes.

docs: w1: w1_therm: Fix broken xref, mistakes, clarify text

sysfs attribute names are mixed with the same normal text terms.
Use ReST to distinguish.

Fix typos and mistakes.

Reported-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
Link: https://lore.kernel.org/r/20201008054259.5461-1-ivan.zaentsev@wirenboard.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

w1: w1_therm: Add support for GXCAS GX20MH01 device.

GX20MH01 device shares family number 0x28 with DS18B20. The device
is generally compatible with DS18B20. Added are the lowest 2^-5, 2

w1: w1_therm: Add support for GXCAS GX20MH01 device.

GX20MH01 device shares family number 0x28 with DS18B20. The device
is generally compatible with DS18B20. Added are the lowest 2^-5, 2^-6
temperature bits in Config register; R2 bit in Config register
enabling 13 and 14 bit resolutions. It is powered up in 14 bit mode.

Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
Link: https://lore.kernel.org/r/20200904160004.87710-2-ivan.zaentsev@wirenboard.ru
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

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

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>

show more ...

docs: ABI: fix a typo when pointing to w1-generic.rst

There's a typo there:

w1_generic.rst -> w1-generic.rst

Causing the document reference to point to the wrong pl

docs: ABI: fix a typo when pointing to w1-generic.rst

There's a typo there:

w1_generic.rst -> w1-generic.rst

Causing the document reference to point to the wrong place.

Fixes: e2c94d6f5720 ("w1_therm: adding alarm sysfs entry")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/66b47dd879e8ae38b6db6d2f38780e00a29fc086.1592895969.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

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

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>

show more ...

w1_therm: adding alarm sysfs entry

Adding device alarms settings by a dedicated sysfs entry alarms (RW):
read or write TH and TL in the device RAM. Checking devices in alarm
state co

w1_therm: adding alarm sysfs entry

Adding device alarms settings by a dedicated sysfs entry alarms (RW):
read or write TH and TL in the device RAM. Checking devices in alarm
state could be performed using the master search command.

As alarms temperature level are store in a 8 bit register on the device
and are signed values, a safe cast shall be performed using the min and
max temperature that device are able to measure. This is done by
int_to_short inline function.

A 'write_data' field is added in the device structure, to bind the
correct writing function, as some devices may have 2 or 3 bytes RAM.

Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly.

Signed-off-by: Akira Shimahara <akira215corp@gmail.com>
Link: https://lore.kernel.org/r/20200511203801.411253-1-akira215corp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

w1_therm: optimizing temperature read timings

Optimizing temperature reading by reducing waiting conversion time
according to device resolution settings, as per device specification.

w1_therm: optimizing temperature read timings

Optimizing temperature reading by reducing waiting conversion time
according to device resolution settings, as per device specification.
This is device dependent as not all the devices supports resolution
setting, so it has been added in device family structures.

The process to read the temperature on the device has been adapted in a
new function 'convert_t()', which replace the former 'read_therm()', is
introduce to deal with this timing. Strong pull up is also applied during
the required time, according to device power status needs and
'strong_pullup' module parameter.

'temperature_from_RAM()' function is introduced to get the correct
temperature computation (device dependent) from device RAM data.

An new sysfs entry has been added to ouptut only temperature. The old
entry w1_slave has been kept for compatibility, without changing its
output format.

Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly.

Signed-off-by: Akira Shimahara <akira215corp@gmail.com>
Link: https://lore.kernel.org/r/20200511203742.411039-1-akira215corp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

w1_therm: adding eeprom sysfs entry

The driver implement 2 hardware functions to access device RAM:
* copy_scratchpad
* recall_scratchpad
They act according to device specifica

w1_therm: adding eeprom sysfs entry

The driver implement 2 hardware functions to access device RAM:
* copy_scratchpad
* recall_scratchpad
They act according to device specifications.

As EEPROM operations are not device dependent (all w1_therm can perform
EEPROM read/write operation following the same protocol), it is removed
from device families structures.

Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly.

Signed-off-by: Akira Shimahara <akira215corp@gmail.com>
Link: https://lore.kernel.org/r/20200511203725.410844-1-akira215corp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

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 se

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>

show more ...

w1_therm: adding ext_power sysfs entry

Adding ext_power sysfs entry (RO). Return the power status of the device:
- 0: device parasite powered
- 1: device externally powered
-

w1_therm: adding ext_power sysfs entry

Adding ext_power sysfs entry (RO). Return the power status of the device:
- 0: device parasite powered
- 1: device externally powered
- xx: xx is kernel error

The power status 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 power state of each device, which could
be used later to determine the required strong pull up to apply on the
line.

The power status is re evaluate each time the sysfs ext_power read by
a user.

The hardware function 'read_powermode(struct w1_slave *sl)' act just as
per device specifications, sending W1_READ_PSUPPLY command on the bus,
and issue a read time slot, reading only one bit.

A helper function 'bool bus_mutex_lock(struct mutex *lock)' is introduced.
It try to aquire the bus mutex several times (W1_THERM_MAX_TRY), waiting
W1_THERM_RETRY_DELAY between two attempt.

Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly.

Signed-off-by: Akira Shimahara <akira215corp@gmail.com>
Link: https://lore.kernel.org/r/20200511203650.410439-1-akira215corp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

w1_therm: adding sysfs-driver-w1_therm doc

Adding a sysfs-driver-w1_therm documentation file in
Documentation/ABI/testing. It describe the onlys sysfs entry of w1_therm
module, based

w1_therm: adding sysfs-driver-w1_therm doc

Adding a sysfs-driver-w1_therm documentation file in
Documentation/ABI/testing. It describe the onlys sysfs entry of w1_therm
module, based on Documentation/w1/slaves/w1_therm.rst

Signed-off-by: Akira Shimahara <akira215corp@gmail.com>
Link: https://lore.kernel.org/r/20200511203631.410227-1-akira215corp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...