20 строки
1.0 KiB
Plaintext
20 строки
1.0 KiB
Plaintext
Any w1 device must be connected to w1 bus master device - for example
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ds9490 usb device or w1-over-GPIO or RS232 converter.
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Driver for w1 bus master must provide several functions(you can find
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them in struct w1_bus_master definition in w1.h) which then will be
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called by w1 core to send various commands over w1 bus(by default it is
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reset and search commands). When some device is found on the bus, w1 core
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checks if driver for it's family is loaded.
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If driver is loaded w1 core creates new w1_slave object and registers it
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in the system(creates some generic sysfs files(struct w1_family_ops in
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w1_family.h), notifies any registered listener and so on...).
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It is device driver's business to provide any communication method
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upstream.
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For example w1_therm driver(ds18?20 thermal sensor family driver)
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provides temperature reading function which is bound to ->rbin() method
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of the above w1_family_ops structure.
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w1_smem - driver for simple 64bit memory cell provides ID reading
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method.
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You can call above methods by reading appropriate sysfs files.
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