embd/leddriver.go

99 lines
2.4 KiB
Go

/*
* Copyright (c) Karan Misra 2014
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
* associated documentation files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
// Generic LED driver.
package embd
import (
"errors"
"fmt"
"strconv"
)
// LEDMap type represents a LED mapping for a host.
type LEDMap map[string][]string
type ledFactory func(string) LED
type ledDriver struct {
ledMap LEDMap
lf ledFactory
initializedLEDs map[string]LED
}
// NewLEDDriver returns a LEDDriver interface which allows control
// over the LED subsystem.
func NewLEDDriver(ledMap LEDMap, lf ledFactory) LEDDriver {
return &ledDriver{
ledMap: ledMap,
lf: lf,
initializedLEDs: map[string]LED{},
}
}
func (d *ledDriver) lookup(k interface{}) (string, error) {
var ks string
switch key := k.(type) {
case int:
ks = strconv.Itoa(key)
case string:
ks = key
case fmt.Stringer:
ks = key.String()
default:
return "", errors.New("led: invalid key type")
}
for id := range d.ledMap {
for _, alias := range d.ledMap[id] {
if alias == ks {
return id, nil
}
}
}
return "", fmt.Errorf("led: no match found for %q", k)
}
func (d *ledDriver) LED(k interface{}) (LED, error) {
id, err := d.lookup(k)
if err != nil {
return nil, err
}
led := d.lf(id)
d.initializedLEDs[id] = led
return led, nil
}
func (d *ledDriver) Close() error {
for _, led := range d.initializedLEDs {
if err := led.Close(); err != nil {
return err
}
}
return nil
}