Add S110 version 8.0.0 SoftDevice for nrf51822

The nrf51822 chip is still widely available, for example in the BBC
micro:bit. Therefore it's a good idea to support it too.

Unfortunately, Nordic decided to change the API in some significant ways
so many parts are not compatible between S110 for nrf51 and the other
nrf52* SoftDevices.

Makefile

@@ -14,6 +14,8 @@ smoketest-tinygo:
 	# Test some more boards that are not tested above.
 	$(TINYGO) build -o test.hex -size=short -target=pca10056-s140v7       ./examples/advertisement
 	@md5sum test.hex
+	$(TINYGO) build -o test.hex -size=short -target=microbit-s110v8       ./examples/advertisement
+	@md5sum test.hex
 
 smoketest-linux:
 	# Test on Linux.

README.md

@@ -18,6 +18,7 @@ As you can see above, there is support for some chips from Nordic Semiconductors
 
   * The [nRF52832](https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF52832) with the [S132](https://www.nordicsemi.com/Software-and-Tools/Software/S132) SoftDevice (version 6).
   * The [nRF52840](https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF52840) with the [S140](https://www.nordicsemi.com/Software-and-Tools/Software/S140) SoftDevice (version 7).
+  * The [nRF51822](https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF51822) with the [S110](https://www.nordicsemi.com/Software-and-Tools/Software/S110) SoftDevice (version 8). This SoftDevice does not support all features (e.g. scanning).
 
 These chips are supported through [TinyGo](https://tinygo.org/).
 
@@ -36,6 +37,14 @@ After that, don't reset the board but instead flash a new program to it. For exa
 
 Flashing will normally reset the board.
 
+For boards that use the CMSIS-DAP interface (such as the [BBC micro:bit](https://microbit.org/)), this works a bit different. Flashing the SoftDevice is done by simply copying the .hex file to the device, for example (on Linux):
+
+    cp path/to/softdevice.hex /media/yourusername/MICROBIT/
+
+Flashing will then need to be done a bit differently, using the CMSIS-DAP interface instead of the mass-storage interface normally used by TinyGo:
+
+    tinygo flash -target=microbit-s110v8 -programmer=cmsis-dap ./examples/heartrate
+
 ## License
 
 This project is licensed under the BSD 3-clause license, see the LICENSE file for details.

adapter_nrf51.go

@@ -0,0 +1,103 @@
+// +build softdevice,s110v8
+
+package bluetooth
+
+/*
+// Define SoftDevice functions as regular function declarations (not inline
+// static functions).
+#define SVCALL_AS_NORMAL_FUNCTION
+
+#include "nrf_sdm.h"
+#include "ble.h"
+#include "ble_gap.h"
+
+void assertHandler(void);
+*/
+import "C"
+
+import "unsafe"
+
+//export assertHandler
+func assertHandler(pc uint32, line_number uint16, p_file_name *byte) {
+	println("SoftDevice assert")
+}
+
+func (a *Adapter) enable() error {
+	// Enable the SoftDevice.
+	errCode := C.sd_softdevice_enable(C.NRF_CLOCK_LFCLKSRC_RC_250_PPM_250MS_CALIBRATION, C.softdevice_assertion_handler_t(C.assertHandler))
+	if errCode != 0 {
+		return Error(errCode)
+	}
+
+	// Enable the BLE stack.
+	enableParams := C.ble_enable_params_t{
+		gatts_enable_params: C.ble_gatts_enable_params_t{
+			attr_tab_size: C.BLE_GATTS_ATTR_TAB_SIZE_DEFAULT,
+		},
+	}
+	errCode = C.sd_ble_enable(&enableParams)
+	return makeError(errCode)
+}
+
+func handleEvent() {
+	id := eventBuf.header.evt_id
+	switch {
+	case id >= C.BLE_GAP_EVT_BASE && id <= C.BLE_GAP_EVT_LAST:
+		gapEvent := eventBuf.evt.unionfield_gap_evt()
+		switch id {
+		case C.BLE_GAP_EVT_CONNECTED:
+			handler := defaultAdapter.handler
+			if handler != nil {
+				handler(&ConnectEvent{GAPEvent: GAPEvent{Connection(gapEvent.conn_handle)}})
+			}
+		case C.BLE_GAP_EVT_DISCONNECTED:
+			handler := defaultAdapter.handler
+			if handler != nil {
+				handler(&DisconnectEvent{GAPEvent: GAPEvent{Connection(gapEvent.conn_handle)}})
+			}
+		case C.BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST:
+			// Respond with the default PPCP connection parameters by passing
+			// nil:
+			// > If NULL is provided on a peripheral role, the parameters in the
+			// > PPCP characteristic of the GAP service will be used instead. If
+			// > NULL is provided on a central role and in response to a
+			// > BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST, the peripheral request
+			// > will be rejected
+			C.sd_ble_gap_conn_param_update(gapEvent.conn_handle, nil)
+		default:
+			if debug {
+				println("unknown GAP event:", id)
+			}
+		}
+	case id >= C.BLE_GATTS_EVT_BASE && id <= C.BLE_GATTS_EVT_LAST:
+		gattsEvent := eventBuf.evt.unionfield_gatts_evt()
+		switch id {
+		case C.BLE_GATTS_EVT_WRITE:
+			writeEvent := gattsEvent.params.unionfield_write()
+			len := writeEvent.len - writeEvent.offset
+			data := (*[255]byte)(unsafe.Pointer(&writeEvent.data[0]))[:len:len]
+			handler := defaultAdapter.getCharWriteHandler(writeEvent.handle)
+			if handler != nil {
+				handler.callback(Connection(gattsEvent.conn_handle), int(writeEvent.offset), data)
+			}
+		case C.BLE_GATTS_EVT_SYS_ATTR_MISSING:
+			// This event is generated when reading the Generic Attribute
+			// service. It appears to be necessary for bonded devices.
+			// From the docs:
+			// > If the pointer is NULL, the system attribute info is
+			// > initialized, assuming that the application does not have any
+			// > previously saved system attribute data for this device.
+			// Maybe we should look at the error, but as there's not really a
+			// way to handle it, ignore it.
+			C.sd_ble_gatts_sys_attr_set(gattsEvent.conn_handle, nil, 0, 0)
+		default:
+			if debug {
+				println("unknown GATTS event:", id, id-C.BLE_GATTS_EVT_BASE)
+			}
+		}
+	default:
+		if debug {
+			println("unknown event:", id)
+		}
+	}
+}

adapter_nrf528xx.go

@@ -0,0 +1,130 @@
+// +build softdevice,!s110v8
+
+package bluetooth
+
+/*
+// Define SoftDevice functions as regular function declarations (not inline
+// static functions).
+#define SVCALL_AS_NORMAL_FUNCTION
+
+#include "nrf_sdm.h"
+#include "ble.h"
+#include "ble_gap.h"
+
+void assertHandler(void);
+*/
+import "C"
+
+import "unsafe"
+
+//export assertHandler
+func assertHandler() {
+	println("SoftDevice assert")
+}
+
+var clockConfig C.nrf_clock_lf_cfg_t = C.nrf_clock_lf_cfg_t{
+	source:       C.NRF_CLOCK_LF_SRC_SYNTH,
+	rc_ctiv:      0,
+	rc_temp_ctiv: 0,
+	accuracy:     0,
+}
+
+func (a *Adapter) enable() error {
+	// Enable the SoftDevice.
+	errCode := C.sd_softdevice_enable(&clockConfig, C.nrf_fault_handler_t(C.assertHandler))
+	if errCode != 0 {
+		return Error(errCode)
+	}
+
+	// Enable the BLE stack.
+	appRAMBase := uint32(0x200039c0)
+	errCode = C.sd_ble_enable(&appRAMBase)
+	return makeError(errCode)
+}
+
+func handleEvent() {
+	id := eventBuf.header.evt_id
+	switch {
+	case id >= C.BLE_GAP_EVT_BASE && id <= C.BLE_GAP_EVT_LAST:
+		gapEvent := eventBuf.evt.unionfield_gap_evt()
+		switch id {
+		case C.BLE_GAP_EVT_CONNECTED:
+			handler := defaultAdapter.handler
+			if handler != nil {
+				handler(&ConnectEvent{GAPEvent: GAPEvent{Connection(gapEvent.conn_handle)}})
+			}
+		case C.BLE_GAP_EVT_DISCONNECTED:
+			handler := defaultAdapter.handler
+			if handler != nil {
+				handler(&DisconnectEvent{GAPEvent: GAPEvent{Connection(gapEvent.conn_handle)}})
+			}
+		case C.BLE_GAP_EVT_ADV_REPORT:
+			advReport := gapEvent.params.unionfield_adv_report()
+			if debug && &scanReportBuffer.data[0] != advReport.data.p_data {
+				// Sanity check.
+				panic("scanReportBuffer != advReport.p_data")
+			}
+			// Prepare the globalScanResult, which will be passed to the
+			// callback.
+			scanReportBuffer.len = byte(advReport.data.len)
+			globalScanResult.RSSI = int16(advReport.rssi)
+			globalScanResult.Address = advReport.peer_addr.addr
+			globalScanResult.AdvertisementPayload = &scanReportBuffer
+			// Signal to the main thread that there was a scan report.
+			// Scanning will be resumed (from the main thread) once the scan
+			// report has been processed.
+			gotScanReport.Set(1)
+		case C.BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST:
+			// Respond with the default PPCP connection parameters by passing
+			// nil:
+			// > If NULL is provided on a peripheral role, the parameters in the
+			// > PPCP characteristic of the GAP service will be used instead. If
+			// > NULL is provided on a central role and in response to a
+			// > BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST, the peripheral request
+			// > will be rejected
+			C.sd_ble_gap_conn_param_update(gapEvent.conn_handle, nil)
+		case C.BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST:
+			// We need to respond with sd_ble_gap_data_length_update. Setting
+			// both parameters to nil will make sure we send the default values.
+			C.sd_ble_gap_data_length_update(gapEvent.conn_handle, nil, nil)
+		default:
+			if debug {
+				println("unknown GAP event:", id)
+			}
+		}
+	case id >= C.BLE_GATTS_EVT_BASE && id <= C.BLE_GATTS_EVT_LAST:
+		gattsEvent := eventBuf.evt.unionfield_gatts_evt()
+		switch id {
+		case C.BLE_GATTS_EVT_WRITE:
+			writeEvent := gattsEvent.params.unionfield_write()
+			len := writeEvent.len - writeEvent.offset
+			data := (*[255]byte)(unsafe.Pointer(&writeEvent.data[0]))[:len:len]
+			handler := defaultAdapter.getCharWriteHandler(writeEvent.handle)
+			if handler != nil {
+				handler.callback(Connection(gattsEvent.conn_handle), int(writeEvent.offset), data)
+			}
+		case C.BLE_GATTS_EVT_SYS_ATTR_MISSING:
+			// This event is generated when reading the Generic Attribute
+			// service. It appears to be necessary for bonded devices.
+			// From the docs:
+			// > If the pointer is NULL, the system attribute info is
+			// > initialized, assuming that the application does not have any
+			// > previously saved system attribute data for this device.
+			// Maybe we should look at the error, but as there's not really a
+			// way to handle it, ignore it.
+			C.sd_ble_gatts_sys_attr_set(gattsEvent.conn_handle, nil, 0, 0)
+		case C.BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST:
+			// This event is generated by some devices. While we could support
+			// larger MTUs, this default MTU is supported everywhere.
+			C.sd_ble_gatts_exchange_mtu_reply(gattsEvent.conn_handle, C.BLE_GATT_ATT_MTU_DEFAULT)
+		default:
+			if debug {
+				println("unknown GATTS event:", id, id-C.BLE_GATTS_EVT_BASE)
+			}
+		}
+	default:
+		if debug {
+			println("unknown event:", id)
+		}
+	}
+}

adapter_s110.c

@@ -0,0 +1,10 @@
+// +build softdevice,s110v8
+
+// This file is necessary to define SVCall wrappers, because TinyGo does not yet
+// support static functions in the preamble.
+
+// Discard all 'static' attributes to define functions normally.
+#define static
+
+#include "s110_nrf51_8.0.0/s110_nrf51_8.0.0_API/include/nrf_sdm.h"
+#include "s110_nrf51_8.0.0/s110_nrf51_8.0.0_API/include/ble.h"

adapter_s110.go

@@ -0,0 +1,10 @@
+// +build softdevice,s110v8
+
+package bluetooth
+
+/*
+// Add the correct SoftDevice include path to CFLAGS, so #include will work as
+// expected.
+#cgo CFLAGS: -Is110_nrf51_8.0.0/s110_nrf51_8.0.0_API/include
+*/
+import "C"