cmd/zedmon/gpio.go

// Copyright 2018 The Fuchsia Authors. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//    * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//    * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//    * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

package main

import (
	"context"
	"flag"
	"log"
	"strconv"

	"fuchsia.googlesource.com/zedmon"
	"github.com/google/subcommands"
)

type gpioCmd struct{}

func (*gpioCmd) Name() string     { return "gpio" }
func (*gpioCmd) Synopsis() string { return "Control Zedmon gpio." }
func (*gpioCmd) Usage() string {
	return `gpio <index> 0|1
`
}

func (*gpioCmd) SetFlags(flags *flag.FlagSet) {
	setCommonFlags(flags)
}

func (*gpioCmd) Execute(_ context.Context, f *flag.FlagSet, _ ...interface{}) subcommands.ExitStatus {
	zedmon, err := zedmon.OpenZedmon(getConfig())
	if err != nil {
		log.Printf("Can't open zendmon: %v", err)
		return subcommands.ExitFailure
	}
	defer zedmon.Close()

	args := f.Args()
	if len(args) != 2 {
		log.Println("Wrong number of arguments.")
		return subcommands.ExitUsageError
	}

	index, err := strconv.Atoi(args[0])
	if err != nil {
		log.Printf("Can't parse index %s: %v", args[0], err)
		return subcommands.ExitUsageError
	}
	if !(0 <= index && index <= 254) {
		log.Printf("Index out of range: %v", index)
		return subcommands.ExitUsageError
	}

	var state bool
	switch args[1] {
	case "1":
		state = true
	case "0":
		state = false
	default:
		log.Printf("Unknown state %s", args[1])
		return subcommands.ExitUsageError
	}

	err = zedmon.SetOuput(uint8(index+1), state)
	if err != nil {
		log.Println(err.Error())
		return subcommands.ExitFailure
	}

	return subcommands.ExitSuccess
}