pbio/drv/bluetooth: Implement inquiry scan.

This adds a handler for Bluetooth classic tasks to the Bluetooth driver.

Co-authored-by: James Aguilar <aguilar.james@gmail.com>

Author: laurensvalk

lib/pbio/drv/bluetooth/bluetooth.c

@@ -13,6 +13,7 @@
 
 #include <pbio/busy_count.h>
 #include <pbio/error.h>
+#include <pbio/int_math.h>
 #include <pbio/os.h>
 #include <pbio/protocol.h>
 
@@ -303,15 +304,6 @@ pbio_error_t pbdrv_bluetooth_await_peripheral_command(pbio_os_state_t *state, vo
     return peri->err;
 }
 
-void pbdrv_bluetooth_cancel_operation_request(void) {
-    // Only some peripheral actions support cancellation.
-    DEBUG_PRINT("Bluetooth operation cancel requested.\n");
-    for (uint8_t i = 0; i < PBDRV_CONFIG_BLUETOOTH_NUM_PERIPHERALS; i++) {
-        pbdrv_bluetooth_peripheral_t *peri = pbdrv_bluetooth_peripheral_get_by_index(i);
-        peri->cancel = true;
-    }
-}
-
 //
 // Functions related to advertising and scanning.
 //
@@ -505,6 +497,60 @@ static bool update_and_get_event_buffer(uint8_t **buf, uint32_t **len) {
     return false;
 }
 
+#if PBDRV_CONFIG_BLUETOOTH_NUM_CLASSIC_CONNECTIONS
+static pbdrv_bluetooth_classic_task_context_t pbdrv_bluetooth_classic_task_context;
+
+pbio_error_t pbdrv_bluetooth_start_inquiry_scan(pbdrv_bluetooth_inquiry_result_t *results, uint32_t *results_count, uint32_t *results_count_max, uint32_t duration_ms) {
+
+    if (!pbdrv_bluetooth_is_connected(PBDRV_BLUETOOTH_CONNECTION_HCI)) {
+        return PBIO_ERROR_INVALID_OP;
+    }
+
+    pbdrv_bluetooth_classic_task_context_t *task = &pbdrv_bluetooth_classic_task_context;
+
+    if (task->func) {
+        return PBIO_ERROR_BUSY;
+    }
+
+    // Initialize newly given task.
+    task->inq_results = results;
+    task->inq_count = results_count;
+    task->inq_count_max = results_count_max;
+    task->inq_duration = pbio_int_math_bind((duration_ms + 640) / 1280, 1, 255);
+
+    // Request handling on the main loop.
+    task->err = PBIO_ERROR_AGAIN;
+    task->func = pbdrv_bluetooth_inquiry_scan_func;
+    task->cancel = false;
+    pbio_os_request_poll();
+    return PBIO_SUCCESS;
+}
+
+pbio_error_t pbdrv_bluetooth_await_classic_task(pbio_os_state_t *state, void *context) {
+
+    pbdrv_bluetooth_classic_task_context_t *task = &pbdrv_bluetooth_classic_task_context;
+
+    // If the user is no longer calling this then the operation is no longer
+    // of interest and will be cancelled if the active function supports it.
+    pbio_os_timer_set(&task->watchdog, 10);
+
+    return task->err;
+}
+#endif // PBDRV_CONFIG_BLUETOOTH_NUM_CLASSIC_CONNECTIONS
+
+void pbdrv_bluetooth_cancel_operation_request(void) {
+    // Only some peripheral actions support cancellation.
+    DEBUG_PRINT("Bluetooth operation cancel requested.\n");
+    for (uint8_t i = 0; i < PBDRV_CONFIG_BLUETOOTH_NUM_PERIPHERALS; i++) {
+        pbdrv_bluetooth_peripheral_t *peri = pbdrv_bluetooth_peripheral_get_by_index(i);
+        peri->cancel = true;
+    }
+    #if PBDRV_CONFIG_BLUETOOTH_NUM_CLASSIC_CONNECTIONS
+    // Revisit: Cancel all.
+    pbdrv_bluetooth_classic_task_context.cancel = true;
+    #endif // PBDRV_CONFIG_BLUETOOTH_NUM_CLASSIC_CONNECTIONS
+}
+
 static bool shutting_down;
 
 /**
@@ -595,6 +641,17 @@ pbio_error_t pbdrv_bluetooth_process_thread(pbio_os_state_t *state, void *contex
             PBIO_OS_AWAIT(state, &sub, pbdrv_bluetooth_start_observing_func(&sub, NULL));
             observe_restart_requested = false;
         }
+
+        #if PBDRV_CONFIG_BLUETOOTH_NUM_CLASSIC_CONNECTIONS
+        // Handle pending Bluetooth classic task, if any.
+        static pbdrv_bluetooth_classic_task_context_t *task;
+        task = &pbdrv_bluetooth_classic_task_context;
+        if (task->func) {
+            PBIO_OS_AWAIT(state, &sub, task->err = task->func(&sub, task));
+            task->func = NULL;
+            task->cancel = false;
+        }
+        #endif // PBDRV_CONFIG_BLUETOOTH_NUM_CLASSIC_CONNECTIONS
     }
 
     DEBUG_PRINT("Shutdown requested.\n");

lib/pbio/drv/bluetooth/bluetooth.h

@@ -55,6 +55,48 @@ extern pbdrv_bluetooth_start_observing_callback_t pbdrv_bluetooth_observe_callba
 
 pbio_error_t pbdrv_bluetooth_process_thread(pbio_os_state_t *state, void *context);
 
+/**
+ * Context for an ongoing classic Bluetooth task.
+ *
+ * Not all fields are used by all functions. Only one function runs at a time.
+ */
+typedef struct {
+    /**
+     * The currently active function.
+     */
+    pbio_os_process_func_t func;
+    /**
+     * The most recent result of calling above function from main process.
+     */
+    pbio_error_t err;
+    /**
+     * Cancellation requested.
+     */
+    bool cancel;
+    /**
+     *  Watchdog for above operation so it can be cancelled on inactivity.
+     */
+    pbio_os_timer_t watchdog;
+    /**
+     * Inquiry scan results.
+     */
+    pbdrv_bluetooth_inquiry_result_t *inq_results;
+    /**
+     * Number of scan results found so far.
+     */
+    uint32_t *inq_count;
+    /**
+     * Maximum number of scan results to find.
+     */
+    uint32_t *inq_count_max;
+    /**
+     * Inquiry duration in units of 1.28 seconds.
+     */
+    uint8_t inq_duration;
+} pbdrv_bluetooth_classic_task_context_t;
+
+pbio_error_t pbdrv_bluetooth_inquiry_scan_func(pbio_os_state_t *state, void *context);
+
 #endif // PBDRV_CONFIG_BLUETOOTH
 
 #endif // _INTERNAL_PBDRV_BLUETOOTH_H_

lib/pbio/drv/bluetooth/bluetooth_btstack.c

@@ -9,6 +9,7 @@
 
 #include <assert.h>
 #include <inttypes.h>
+#include <stdio.h>
 
 #include <ble/gatt-service/device_information_service_server.h>
 #include <ble/gatt-service/nordic_spp_service_server.h>
@@ -1094,6 +1095,64 @@ pbio_error_t pbdrv_bluetooth_stop_observing_func(pbio_os_state_t *state, void *c
     PBIO_OS_ASYNC_END(PBIO_SUCCESS);
 }
 
+static void pbdrv_bluetooth_inquiry_unpack_scan_event(uint8_t *event_packet, pbdrv_bluetooth_inquiry_result_t *result) {
+
+    gap_event_inquiry_result_get_bd_addr(event_packet, result->bdaddr);
+    if (gap_event_inquiry_result_get_rssi_available(event_packet)) {
+        result->rssi = gap_event_inquiry_result_get_rssi(event_packet);
+    }
+
+    if (gap_event_inquiry_result_get_name_available(event_packet)) {
+        const uint8_t *name = gap_event_inquiry_result_get_name(event_packet);
+        const size_t name_len = gap_event_inquiry_result_get_name_len(event_packet);
+        snprintf(result->name, sizeof(result->name), "%.*s", (int)name_len, name);
+    }
+
+    result->class_of_device = gap_event_inquiry_result_get_class_of_device(event_packet);
+}
+
+pbio_error_t pbdrv_bluetooth_inquiry_scan_func(pbio_os_state_t *state, void *context) {
+
+    pbdrv_bluetooth_classic_task_context_t *task = context;
+
+    if (!task->cancel) {
+        task->cancel = pbio_os_timer_is_expired(&task->watchdog);
+    }
+
+    PBIO_OS_ASYNC_BEGIN(state);
+
+    DEBUG_PRINT("Start inquiry scan.\n");
+
+    gap_inquiry_start(task->inq_duration);
+
+    // Wait until scan timeout or the number of devices are found.
+    PBIO_OS_AWAIT_UNTIL(state, (*task->inq_count == *task->inq_count_max) || ({
+
+        if (task->cancel || *task->inq_count_max == 0) {
+            // Cancelled or the external data no longer available. Stop
+            // scanning and don't write any more data.
+            DEBUG_PRINT("Inquiry scan canceled.\n");
+            gap_inquiry_stop();
+            return PBIO_ERROR_CANCELED;
+        }
+
+        // Process a scan result.
+        if (hci_event_is_type(event_packet, GAP_EVENT_INQUIRY_RESULT)) {
+            DEBUG_PRINT("Received scan result.\n");
+            pbdrv_bluetooth_inquiry_result_t *result = &task->inq_results[(*task->inq_count)++];
+            pbdrv_bluetooth_inquiry_unpack_scan_event(event_packet, result);
+
+        }
+
+        // The wait until condition: inquiry complete.
+        hci_event_is_type(event_packet, GAP_EVENT_INQUIRY_COMPLETE);
+    }));
+
+    DEBUG_PRINT("Inquiry scan ended with %d results.\n", *task->inq_count);
+
+    PBIO_OS_ASYNC_END(PBIO_SUCCESS);
+}
+
 const char *pbdrv_bluetooth_get_hub_name(void) {
     return pbdrv_bluetooth_hub_name;
 }

lib/pbio/include/pbdrv/bluetooth.h

@@ -585,6 +585,30 @@ typedef struct {
     uint32_t class_of_device;
 } pbdrv_bluetooth_inquiry_result_t;
 
+/**
+ * Starts a classic Bluetooth inquiry scan.
+ *
+ * @param [in] results                Array to store results.
+ * @param [in] results_count          Number of results found.
+ * @param [in] results_count_max      Maximum number of results to find. Will
+ *                                    stop if externally reset to 0.
+ * @param [in] duration_ms            Duration of the inquiry scan in milliseconds.
+ *                                    It will be internally rounded to the nearest
+ *                                    supported nonzero value.
+ */
+pbio_error_t pbdrv_bluetooth_start_inquiry_scan(pbdrv_bluetooth_inquiry_result_t *results, uint32_t *results_count, uint32_t *results_count_max, uint32_t duration_ms);
+
+/**
+ * Awaits for the classic Bluetooth inquiry scan to complete.
+ *
+ * @param [in]  state          Protothread state.
+ * @param [in]  context        Not used.
+ * @return                     ::PBIO_SUCCESS on completion.
+ *                             ::PBIO_ERROR_AGAIN while awaiting.
+ *                             or an thread specific error code if the operation failed.
+ */
+pbio_error_t pbdrv_bluetooth_await_classic_task(pbio_os_state_t *state, void *context);
+
 #else // PBDRV_CONFIG_BLUETOOTH
 
 static inline void pbdrv_bluetooth_init(void) {

lib/pbio/platform/essential_hub/btstack_config.h

@@ -8,6 +8,7 @@
 
 // BTstack features that can be enabled
 #define ENABLE_BLE
+#define ENABLE_CLASSIC
 // #define ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
 #define ENABLE_LE_CENTRAL
 #define ENABLE_LE_PERIPHERAL

lib/pbio/platform/essential_hub/pbdrvconfig.h

@@ -26,6 +26,7 @@
 #define PBDRV_CONFIG_BATTERY_ADC_TEMPERATURE_CH     2
 
 #define PBDRV_CONFIG_BLUETOOTH                      (1)
+#define PBDRV_CONFIG_BLUETOOTH_NUM_CLASSIC_CONNECTIONS (2)
 #define PBDRV_CONFIG_BLUETOOTH_NUM_PERIPHERALS      (2)
 #define PBDRV_CONFIG_BLUETOOTH_MAX_MTU_SIZE         515
 #define PBDRV_CONFIG_BLUETOOTH_BTSTACK              (1)

lib/pbio/platform/ev3/pbdrvconfig.h

@@ -46,6 +46,7 @@
 #define PBDRV_CONFIG_I2C_EV3                        (1)
 
 #define PBDRV_CONFIG_BLUETOOTH                      (1)
+#define PBDRV_CONFIG_BLUETOOTH_NUM_CLASSIC_CONNECTIONS (2)
 #define PBDRV_CONFIG_BLUETOOTH_NUM_PERIPHERALS      (2)
 #define PBDRV_CONFIG_BLUETOOTH_MAX_MTU_SIZE         515
 #define PBDRV_CONFIG_BLUETOOTH_BTSTACK              (1)

lib/pbio/platform/prime_hub/btstack_config.h

@@ -8,6 +8,7 @@
 
 // BTstack features that can be enabled
 #define ENABLE_BLE
+#define ENABLE_CLASSIC
 // #define ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
 #define ENABLE_LE_CENTRAL
 #define ENABLE_LE_PERIPHERAL

lib/pbio/platform/prime_hub/pbdrvconfig.h

@@ -26,6 +26,7 @@
 #define PBDRV_CONFIG_BATTERY_ADC_TEMPERATURE_CH     2
 
 #define PBDRV_CONFIG_BLUETOOTH                      (1)
+#define PBDRV_CONFIG_BLUETOOTH_NUM_CLASSIC_CONNECTIONS (2)
 #define PBDRV_CONFIG_BLUETOOTH_NUM_PERIPHERALS      (2)
 #define PBDRV_CONFIG_BLUETOOTH_MAX_MTU_SIZE         515
 #define PBDRV_CONFIG_BLUETOOTH_BTSTACK              (1)

lib/pbio/platform/virtual_hub/pbdrvconfig.h

@@ -11,6 +11,7 @@
 // Use Bluetooth simulation locally.
 #ifndef PBDRV_CONFIG_RUN_ON_CI
 #define PBDRV_CONFIG_BLUETOOTH                              (1)
+#define PBDRV_CONFIG_BLUETOOTH_NUM_CLASSIC_CONNECTIONS      (2)
 #define PBDRV_CONFIG_BLUETOOTH_NUM_PERIPHERALS              (2)
 #define PBDRV_CONFIG_BLUETOOTH_BTSTACK                      (1)
 #define PBDRV_CONFIG_BLUETOOTH_BTSTACK_LE_SERVER            (1)