Akira Shimahara 57c76221d5 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>		2020-05-15 16:29:00 +02:00
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index.rst	docs: w1: convert to ReST and add to the kAPI group of docs	2019-07-31 14:16:17 -06:00
w1_ds28e04.rst	docs: w1: convert to ReST and add to the kAPI group of docs	2019-07-31 14:16:17 -06:00
w1_ds28e17.rst	docs: w1: convert to ReST and add to the kAPI group of docs	2019-07-31 14:16:17 -06:00
w1_ds2406.rst	docs: w1: convert to ReST and add to the kAPI group of docs	2019-07-31 14:16:17 -06:00
w1_ds2413.rst	docs: w1: convert to ReST and add to the kAPI group of docs	2019-07-31 14:16:17 -06:00
w1_ds2423.rst	docs: w1: convert to ReST and add to the kAPI group of docs	2019-07-31 14:16:17 -06:00
w1_ds2438.rst	docs: w1: convert to ReST and add to the kAPI group of docs	2019-07-31 14:16:17 -06:00
w1_therm.rst	w1_therm: adding bulk read support to trigger multiple conversion on bus	2020-05-15 16:29:00 +02:00