unix: Add support for modbluetooth and BLE using btstack.

This commit adds full support to the unix port for Bluetooth using the
common extmod/modbluetooth Python bindings.  This uses the libusb HCI
transport, which supports many common USB BT adaptors.

docs/library/ubluetooth.rst

@@ -48,6 +48,8 @@ Configuration
     - ``'mac'``: Returns the device MAC address. If a device has a fixed address
       (e.g. PYBD) then it will be returned. Otherwise (e.g. ESP32) a random
       address will be generated when the BLE interface is made active.
+      Note: on some ports, accessing this value requires that the interface is
+      active (so that the MAC address can be queried from the controller).
 
     - ``'rxbuf'``: Get/set the size in bytes of the internal buffer used to store
       incoming events.  This buffer is global to the entire BLE driver and so

extmod/btstack/btstack.mk

@@ -2,6 +2,8 @@
 
 ifeq ($(MICROPY_BLUETOOTH_BTSTACK),1)
 
+MICROPY_BLUETOOTH_BTSTACK_USB ?= 0
+
 BTSTACK_EXTMOD_DIR = extmod/btstack
 
 EXTMOD_SRC_C += extmod/btstack/modbluetooth_btstack.c
@@ -24,9 +26,17 @@ INC += -I$(BTSTACK_DIR)/3rd-party/yxml
 SRC_BTSTACK = \
 	$(addprefix lib/btstack/src/, $(SRC_FILES)) \
 	$(addprefix lib/btstack/src/ble/, $(filter-out %_tlv.c, $(SRC_BLE_FILES))) \
-	lib/btstack/platform/embedded/btstack_run_loop_embedded.c \
+	lib/btstack/platform/embedded/btstack_run_loop_embedded.c
 
-ifeq ($MICROPY_BLUETOOTH_BTSTACK_ENABLE_CLASSIC,1)
+ifeq ($(MICROPY_BLUETOOTH_BTSTACK_USB),1)
+SRC_BTSTACK += \
+	lib/btstack/platform/libusb/hci_transport_h2_libusb.c
+
+CFLAGS  += $(shell pkg-config libusb-1.0 --cflags)
+LDFLAGS += $(shell pkg-config libusb-1.0 --libs)
+endif
+
+ifeq ($(MICROPY_BLUETOOTH_BTSTACK_ENABLE_CLASSIC),1)
 include $(BTSTACK_DIR)/src/classic/Makefile.inc
 SRC_BTSTACK += \
 	$(addprefix lib/btstack/src/classic/, $(SRC_CLASSIC_FILES))

extmod/btstack/btstack_config.h

@@ -41,4 +41,7 @@
 // BTstack HAL configuration
 #define HAVE_EMBEDDED_TIME_MS
 
+// Some USB dongles take longer to respond to HCI reset (e.g. BCM20702A).
+#define HCI_RESET_RESEND_TIMEOUT_MS 1000
+
 #endif // MICROPY_INCLUDED_EXTMOD_BTSTACK_BTSTACK_CONFIG_H

ports/unix/Makefile

@@ -132,6 +132,19 @@ CFLAGS_MOD += -DMICROPY_PY_THREAD=1 -DMICROPY_PY_THREAD_GIL=0
 LDFLAGS_MOD += $(LIBPTHREAD)
 endif
 
+ifeq ($(MICROPY_PY_BLUETOOTH),1)
+CFLAGS_MOD += -DMICROPY_PY_BLUETOOTH=1
+CFLAGS_MOD += -DMICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE=1
+CFLAGS_MOD += -DMICROPY_PY_BLUETOOTH_GATTS_ON_READ_CALLBACK=1
+
+MICROPY_BLUETOOTH_BTSTACK ?= 1
+MICROPY_BLUETOOTH_BTSTACK_USB ?= 1
+endif
+
+ifeq ($(MICROPY_BLUETOOTH_BTSTACK),1)
+include $(TOP)/extmod/btstack/btstack.mk
+endif
+
 ifeq ($(MICROPY_PY_FFI),1)
 
 ifeq ($(MICROPY_STANDALONE),1)
@@ -176,10 +189,11 @@ SRC_C = \
 	alloc.c \
 	coverage.c \
 	fatfs_port.c \
+	btstack_usb.c \
 	$(SRC_MOD) \
 	$(wildcard $(VARIANT_DIR)/*.c)
 
-LIB_SRC_C = $(addprefix lib/,\
+LIB_SRC_C += $(addprefix lib/,\
 	$(LIB_SRC_C_EXTRA) \
 	timeutils/timeutils.c \
 	)
@@ -187,9 +201,10 @@ LIB_SRC_C = $(addprefix lib/,\
 OBJ = $(PY_O)
 OBJ += $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(LIB_SRC_C:.c=.o))
+OBJ += $(addprefix $(BUILD)/, $(EXTMOD_SRC_C:.c=.o))
 
 # List of sources for qstr extraction
-SRC_QSTR += $(SRC_C) $(LIB_SRC_C)
+SRC_QSTR += $(SRC_C) $(LIB_SRC_C) $(EXTMOD_SRC_C)
 # Append any auto-generated sources that are needed by sources listed in
 # SRC_QSTR
 SRC_QSTR_AUTO_DEPS +=

ports/unix/btstack_usb.c

@@ -0,0 +1,170 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Jim Mussared
+ *
+ * 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.
+ */
+
+#include <pthread.h>
+#include <unistd.h>
+
+#include "py/runtime.h"
+#include "py/mperrno.h"
+#include "py/mphal.h"
+
+#if MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_BTSTACK
+
+#include "lib/btstack/src/btstack.h"
+#include "lib/btstack/platform/embedded/btstack_run_loop_embedded.h"
+
+#include "extmod/btstack/modbluetooth_btstack.h"
+
+#if !MICROPY_PY_THREAD
+#error Unix btstack requires MICROPY_PY_THREAD
+#endif
+
+STATIC const useconds_t USB_POLL_INTERVAL_US = 1000;
+
+STATIC const uint8_t read_static_address_command_complete_prefix[] = { 0x0e, 0x1b, 0x01, 0x09, 0xfc };
+
+STATIC uint8_t local_addr[6] = {0};
+STATIC uint8_t static_address[6] = {0};
+STATIC volatile bool have_addr = false;
+STATIC bool using_static_address = false;
+
+STATIC btstack_packet_callback_registration_t hci_event_callback_registration;
+
+STATIC void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
+    (void)channel;
+    (void)size;
+    if (packet_type != HCI_EVENT_PACKET) {
+        return;
+    }
+    switch (hci_event_packet_get_type(packet)) {
+        case BTSTACK_EVENT_STATE:
+            if (btstack_event_state_get_state(packet) != HCI_STATE_WORKING) {
+                return;
+            }
+            gap_local_bd_addr(local_addr);
+            if (using_static_address) {
+                memcpy(local_addr, static_address, sizeof(local_addr));
+            }
+            have_addr = true;
+            break;
+        case HCI_EVENT_COMMAND_COMPLETE:
+            if (memcmp(packet, read_static_address_command_complete_prefix, sizeof(read_static_address_command_complete_prefix)) == 0) {
+                reverse_48(&packet[7], static_address);
+                gap_random_address_set(static_address);
+                using_static_address = true;
+                have_addr = true;
+            }
+            break;
+        default:
+            break;
+    }
+}
+
+// The IRQ functionality in btstack_run_loop_embedded.c is not used, so the
+// following three functions are empty.
+
+void hal_cpu_disable_irqs(void) {
+}
+
+void hal_cpu_enable_irqs(void) {
+}
+
+void hal_cpu_enable_irqs_and_sleep(void) {
+}
+
+uint32_t hal_time_ms(void) {
+    return mp_hal_ticks_ms();
+}
+
+void mp_bluetooth_btstack_port_init(void) {
+    static bool run_loop_init = false;
+    if (!run_loop_init) {
+        run_loop_init = true;
+        btstack_run_loop_init(btstack_run_loop_embedded_get_instance());
+    } else {
+        btstack_run_loop_embedded_get_instance()->init();
+    }
+
+    // TODO: allow setting USB device path via cmdline/env var.
+
+    // hci_dump_open(NULL, HCI_DUMP_STDOUT);
+    hci_init(hci_transport_usb_instance(), NULL);
+
+    hci_event_callback_registration.callback = &packet_handler;
+    hci_add_event_handler(&hci_event_callback_registration);
+}
+
+STATIC pthread_t bstack_thread_id;
+
+void mp_bluetooth_btstack_port_deinit(void) {
+    hci_power_control(HCI_POWER_OFF);
+
+    // Wait for the poll loop to terminate when the state is set to OFF.
+    pthread_join(bstack_thread_id, NULL);
+    have_addr = false;
+}
+
+STATIC void *btstack_thread(void *arg) {
+    (void)arg;
+    hci_power_control(HCI_POWER_ON);
+
+    // modbluetooth_btstack.c will have set the state to STARTING before
+    // calling mp_bluetooth_btstack_port_start.
+    // This loop will terminate when the HCI_POWER_OFF above results
+    // in modbluetooth_btstack.c setting the state back to OFF.
+    // Or, if a timeout results in it being set to TIMEOUT.
+
+    while (mp_bluetooth_btstack_state == MP_BLUETOOTH_BTSTACK_STATE_STARTING || mp_bluetooth_btstack_state == MP_BLUETOOTH_BTSTACK_STATE_ACTIVE) {
+        btstack_run_loop_embedded_execute_once();
+
+        // The USB transport schedules events to the run loop at 1ms intervals,
+        // and the implementation currently polls rather than selects.
+        usleep(USB_POLL_INTERVAL_US);
+    }
+
+    hci_close();
+
+    return NULL;
+}
+
+void mp_bluetooth_btstack_port_start(void) {
+    // Create a thread to run the btstack loop.
+    pthread_attr_t attr;
+    pthread_attr_init(&attr);
+    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+    pthread_create(&bstack_thread_id, &attr, &btstack_thread, NULL);
+}
+
+void mp_hal_get_mac(int idx, uint8_t buf[6]) {
+    if (idx == MP_HAL_MAC_BDADDR) {
+        if (!have_addr) {
+            mp_raise_OSError(MP_ENODEV);
+        }
+        memcpy(buf, local_addr, sizeof(local_addr));
+    }
+}
+
+#endif // MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_BTSTACK

ports/unix/main.c

@@ -683,6 +683,11 @@ MP_NOINLINE int main_(int argc, char **argv) {
     }
     #endif
 
+    #if MICROPY_PY_BLUETOOTH
+    void mp_bluetooth_deinit(void);
+    mp_bluetooth_deinit();
+    #endif
+
     #if MICROPY_PY_THREAD
     mp_thread_deinit();
     #endif

ports/unix/mpconfigport.h

@@ -311,9 +311,17 @@ void mp_unix_mark_exec(void);
 
 #define MP_STATE_PORT MP_STATE_VM
 
+#if MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_BTSTACK
+struct _mp_bluetooth_btstack_root_pointers_t;
+#define MICROPY_BLUETOOTH_ROOT_POINTERS struct _mp_bluetooth_btstack_root_pointers_t *bluetooth_btstack_root_pointers;
+#else
+#define MICROPY_BLUETOOTH_ROOT_POINTERS
+#endif
+
 #define MICROPY_PORT_ROOT_POINTERS \
     const char *readline_hist[50]; \
     void *mmap_region_head; \
+    MICROPY_BLUETOOTH_ROOT_POINTERS \
 
 // We need to provide a declaration/definition of alloca()
 // unless support for it is disabled.

ports/unix/mphalport.h

@@ -95,3 +95,11 @@ static inline void mp_hal_delay_us(mp_uint_t us) {
 #define RAISE_ERRNO(err_flag, error_val) \
     { if (err_flag == -1) \
       { mp_raise_OSError(error_val); } }
+
+#if MICROPY_PY_BLUETOOTH
+enum {
+    MP_HAL_MAC_BDADDR,
+};
+
+void mp_hal_get_mac(int idx, uint8_t buf[6]);
+#endif