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2020-10-08docs: w1: w1_therm: Fix broken xref, mistakes, clarify textIvan Zaentsev1-3/+3
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>
2020-10-02w1: w1_therm: Add support for GXCAS GX20MH01 device.Ivan Zaentsev1-2/+2
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>
2020-10-02w1: w1_therm: Add sysfs entries to control conversion time and driver featuresIvan Zaentsev1-0/+47
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>
2020-06-26docs: ABI: fix a typo when pointing to w1-generic.rstMauro Carvalho Chehab1-1/+1
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>
2020-05-15w1_therm: adding bulk read support to trigger multiple conversion on busAkira Shimahara1-4/+32
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>
2020-05-15w1_therm: adding alarm sysfs entryAkira Shimahara1-0/+16
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>
2020-05-15w1_therm: optimizing temperature read timingsAkira Shimahara1-0/+12
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>
2020-05-15w1_therm: adding eeprom sysfs entryAkira Shimahara1-0/+14
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>
2020-05-15w1_therm: adding resolution sysfs entryAkira Shimahara1-0/+17
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>
2020-05-15w1_therm: adding ext_power sysfs entryAkira Shimahara1-0/+12
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>
2020-05-15w1_therm: adding sysfs-driver-w1_therm docAkira Shimahara1-0/+17
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>