Initial support for more current Raspberry Pi models (i.e. 5) (#65)

* start work, based on https://github.com/AndrewFromMelbourne/raspberry_pi_revision/blob/master/raspberry_pi_revision.c

* this isn't right yet, need to find datasheets, and this switch needs a lot more cases

* docmument research

---------

Co-authored-by: Bluefooted Boobie <scot@birdhouse>

bcm283x/gpio.go

@@ -1338,21 +1338,24 @@ func (d *driverGPIO) Init() (bool, error) {
 	// Let's play safe here.
 	dTCompatible := strings.Join(distro.DTCompatible(), " ")
 	// Reference: https://www.raspberrypi.org/documentation/hardware/raspberrypi/peripheral_addresses.md
-	if strings.Contains(dTCompatible, "bcm2708") ||
-		strings.Contains(dTCompatible, "bcm2835") {
+	switch {
+	case strings.Contains(dTCompatible, "bcm2708"), strings.Contains(dTCompatible, "bcm2835"):
 		// RPi0/1.
 		d.baseAddr = 0x20000000
 		d.dramBus = 0x40000000
 		d.useLegacyPull = true
-	} else if strings.Contains(dTCompatible, "bcm2709") ||
-		strings.Contains(dTCompatible, "bcm2836") ||
-		strings.Contains(dTCompatible, "bcm2710") ||
-		strings.Contains(dTCompatible, "bcm2837") {
+	case strings.Contains(dTCompatible, "bcm2709"), strings.Contains(dTCompatible, "bcm2836"), strings.Contains(dTCompatible, "bcm2710"), strings.Contains(dTCompatible, "bcm2837"):
 		// RPi2+
 		d.baseAddr = 0x3F000000
 		d.dramBus = 0xC0000000
 		d.useLegacyPull = true
-	} else {
+	case strings.Contains(dTCompatible, "bcm2712"):
+		// RPi5 -- https://github.com/WiringPi/WiringPi/blob/master/wiringPi/wiringPi.c doesn't look optimistic
+		d.baseAddr = 0xFE000000
+		d.dramBus = 0xC0000000
+		d.useLegacyPull = false
+		mapping = mapping2711
+	default:
 		// RPi4B+
 		d.baseAddr = 0xFE000000
 		d.dramBus = 0xC0000000
@@ -1370,6 +1373,7 @@ func (d *driverGPIO) Init() (bool, error) {
 	// virtual address space starting at address 0xF2000000. Thus a peripheral
 	// advertised here at bus address 0x7Ennnnnn is available in the ARM kenel at
 	// virtual address 0xF2nnnnnn.
+
 	d.gpioBaseAddr = d.baseAddr + 0x200000
 
 	// Mark the right pins as available even if the memory map fails so they can

rpi/rpi.go

@@ -385,6 +385,7 @@ const (
 	memory2GB   revisionCode = 3 << memoryShift
 	memory4GB   revisionCode = 4 << memoryShift
 	memory8GB   revisionCode = 5 << memoryShift
+	memory16GB  revisionCode = 6 << memoryShift
 
 	sonyUK    revisionCode = 0 << manufacturerShift
 	egoman    revisionCode = 1 << manufacturerShift
@@ -397,6 +398,7 @@ const (
 	bcm2836 revisionCode = 1 << processorShift
 	bcm2837 revisionCode = 2 << processorShift
 	bcm2711 revisionCode = 3 << processorShift
+	bcm2712 revisionCode = 4 << processorShift
 
 	board1A       revisionCode = 0x0 << boardShift
 	board1B       revisionCode = 0x1 << boardShift
@@ -417,6 +419,11 @@ const (
 	boardZero2W   revisionCode = 0x12 << boardShift
 	board400      revisionCode = 0x13 << boardShift
 	boardCM4      revisionCode = 0x14 << boardShift
+	boardCM4S     revisionCode = 0x15 << boardShift
+	board5        revisionCode = 0x17 << boardShift
+	boardCM5      revisionCode = 0x18 << boardShift
+	board500      revisionCode = 0x19 << boardShift
+	boardCM5Lite  revisionCode = 0x20 << boardShift
 )
 
 // features represents the different features on various Raspberry Pi boards.
@@ -514,6 +521,11 @@ func (f *features) init(v uint32) error {
 		f.hdrHDMI = true
 	case boardCM4:
 		// Compute Module does not have a SODIMM header.
+	case board5:
+		f.hdrP1P40 = true
+		f.hdrAudio = true
+		f.audioLeft41 = true
+		f.hdrHDMI = true
 	default:
 		return fmt.Errorf("rpi: unknown hardware version: 0x%x", r)
 	}