46 lines
1.7 KiB
Go
46 lines
1.7 KiB
Go
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// Copyright 2016 The Periph Authors. All rights reserved.
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// Use of this source code is governed under the Apache License, Version 2.0
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// that can be found in the LICENSE file.
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// Package driver devices a host peripheral driver to register when
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// initializing.
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//
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// Drivers that can be automatically discovered should be registered in
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// driverreg so discovery is done automatically.
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package driver
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// Impl is a host peripheral driver implementation.
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type Impl interface {
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// String returns the name of the driver, as to be presented to the user.
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//
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// It must be unique in the list of registered drivers.
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String() string
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// Prerequisites returns a list of drivers that must be successfully loaded
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// first before attempting to load this driver.
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//
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// A driver listing a prerequisite not registered is a fatal failure at
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// initialization time.
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Prerequisites() []string
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// After returns a list of drivers that must be loaded first before
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// attempting to load this driver.
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//
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// Unlike Prerequisites(), this driver will still be attempted even if the
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// listed driver is missing or failed to load.
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//
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// This permits serialization without hard requirement.
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After() []string
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// Init initializes the driver.
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//
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// A driver may enter one of the three following state: loaded successfully,
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// was skipped as irrelevant on this host, failed to load.
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//
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// On success, it must return true, nil.
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//
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// When irrelevant (skipped), it must return false, errors.New(<reason>).
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//
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// On failure, it must return true, errors.New(<reason>). The failure must
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// state why it failed, for example an expected OS provided driver couldn't
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// be opened, e.g. /dev/gpiomem on Raspbian.
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Init() (bool, error)
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}
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