mirror of https://github.com/kidoman/embd
87 lines
1.7 KiB
Go
87 lines
1.7 KiB
Go
// Pin mapping support.
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package embd
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import (
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"fmt"
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"strconv"
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)
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const (
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// CapDigital represents the digital IO capability.
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CapDigital int = 1 << iota
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// CapI2C represents pins with the I2C capability.
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CapI2C
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// CapUART represents pins with the UART capability.
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CapUART
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// CapSPI represents pins with the SPI capability.
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CapSPI
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// CapGPMS represents pins with the GPMC capability.
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CapGPMC
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// CapLCD represents pins used to carry LCD data.
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CapLCD
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// CapPWM represents pins with PWM capability.
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CapPWM
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// CapAnalog represents pins with analog IO capability.
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CapAnalog
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)
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// PinDesc represents a pin descriptor.
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type PinDesc struct {
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ID string
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Aliases []string
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Caps int
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DigitalLogical int
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AnalogLogical int
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}
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// PinMap type represents a collection of pin descriptors.
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type PinMap []*PinDesc
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// Lookup returns a pin descriptor matching the provided key and capability
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// combination. This allows the same keys to be used across pins with differing
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// capabilities. For example, it is perfectly fine to have:
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//
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// pin1: {Aliases: [10, GPIO10], Cap: CapDigital}
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// pin2: {Aliases: [10, AIN0], Cap: CapAnalog}
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//
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// Searching for 10 with CapDigital will return pin1 and searching for
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// 10 with CapAnalog will return pin2. This makes for a very pleasant to use API.
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func (m PinMap) Lookup(k interface{}, cap int) (*PinDesc, bool) {
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var ks string
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switch key := k.(type) {
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case int:
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ks = strconv.Itoa(key)
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case string:
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ks = key
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case fmt.Stringer:
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ks = key.String()
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default:
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return nil, false
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}
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for i := range m {
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pd := m[i]
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if pd.ID == ks {
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return pd, true
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}
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for j := range pd.Aliases {
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if pd.Aliases[j] == ks && pd.Caps&cap != 0 {
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return pd, true
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}
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}
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}
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return nil, false
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}
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