Add support for HID Keyboard LEDs

tinygo-org · Aug 5, 2023 · 60d5fe1 · 60d5fe1
1 parent 67ec722
commit 60d5fe1
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Showing 4 changed files with 40 additions and 2 deletions.
diff --git a/src/machine/usb/descriptor/hid.go b/src/machine/usb/descriptor/hid.go
@@ -26,7 +26,7 @@ var interfaceHID = [interfaceTypeLen]byte{
 	TypeInterface,
 	0x02, // InterfaceNumber
 	0x00, // AlternateSetting
-	0x01, // NumEndpoints
+	0x02, // NumEndpoints
 	0x03, // InterfaceClass
 	0x00, // InterfaceSubClass
 	0x00, // InterfaceProtocol
@@ -103,7 +103,7 @@ var classHID = [ClassHIDTypeLen]byte{
 	0x00, // CountryCode
 	0x01, // NumDescriptors
 	0x22, // ClassType
-	0x7E, // ClassLength L
+	0x90, // ClassLength L
 	0x00, // ClassLength H
 }
 
@@ -128,6 +128,7 @@ var CDCHID = Descriptor{
 		InterfaceHID.Bytes(),
 		ClassHID.Bytes(),
 		EndpointEP4IN.Bytes(),
+		EndpointEP5OUT.Bytes(),
 	}),
 	HID: map[uint16][]byte{
 		2: Append([][]byte{
@@ -147,6 +148,15 @@ var CDCHID = Descriptor{
 			HIDReportCount(1),
 			HIDReportSize(8),
 			HIDInputConstVarAbs,
+			HIDReportCount(3),
+			HIDReportSize(1),
+			HIDUsagePageLED,
+			HIDUsageMinimum(1),
+			HIDUsageMaximum(3),
+			HIDOutputDataVarAbs,
+			HIDReportCount(5),
+			HIDReportSize(1),
+			HIDOutputConstVarAbs,
 			HIDReportCount(6),
 			HIDReportSize(8),
 			HIDLogicalMinimum(0),

diff --git a/src/machine/usb/descriptor/hidreport.go b/src/machine/usb/descriptor/hidreport.go
@@ -13,6 +13,7 @@ const (
 	hidUnit            = 0x65
 	hidCollection      = 0xa1
 	hidInput           = 0x81
+	hidOutput          = 0x91
 	hidReportSize      = 0x75
 	hidReportCount     = 0x95
 	hidReportID        = 0x85
@@ -121,6 +122,12 @@ var (
 
 	// Input (Data, Variable, Relative), 2 position bytes (X & Y)
 	HIDInputDataVarRel = []byte{hidInput, 0x06}
+
+	// Output (Data, Variable, Absolute), Modifier byte
+	HIDOutputDataVarAbs = []byte{hidOutput, 0x02}
+
+	// Output (Const, Variable, Absolute), Modifier byte
+	HIDOutputConstVarAbs = []byte{hidOutput, 0x03}
 )
 
 func HIDReportSize(size int) []byte {

diff --git a/src/machine/usb/hid/hid.go b/src/machine/usb/hid/hid.go
@@ -36,6 +36,12 @@ func SetHandler(d hidDevicer) {
 	if size == 0 {
 		machine.ConfigureUSBEndpoint(descriptor.CDCHID,
 			[]usb.EndpointConfig{
+				{
+					Index:     usb.HID_ENDPOINT_OUT,
+					IsIn:      false,
+					Type:      usb.ENDPOINT_TYPE_INTERRUPT,
+					RxHandler: rxHandler,
+				},
 				{
 					Index:     usb.HID_ENDPOINT_IN,
 					IsIn:      true,

diff --git a/src/machine/usb/hid/keyboard/keyboard.go b/src/machine/usb/hid/keyboard/keyboard.go
@@ -92,6 +92,9 @@ func (kb *keyboard) TxHandler() bool {
 }
 
 func (kb *keyboard) RxHandler(b []byte) bool {
+	if len(b) >= 2 && b[0] == 2 /* ReportID */ {
+		kb.led = b[1]
+	}
 	return false
 }
 
@@ -106,6 +109,18 @@ func (kb *keyboard) tx(b []byte) {
 	}
 }
 
+func (kb *keyboard) NumLockLed() bool {
+	return kb.led&1 != 0
+}
+
+func (kb *keyboard) CapsLockLed() bool {
+	return kb.led&2 != 0
+}
+
+func (kb *keyboard) ScrollLockLed() bool {
+	return kb.led&4 != 0
+}
+
 func (kb *keyboard) ready() bool {
 	return true
 }