Diff: microbit/microbit-dal/nRF51822/source/nRF5xGap.h

Revision:

0:b9164b348919

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/microbit/microbit-dal/nRF51822/source/nRF5xGap.h	Mon Oct 17 12:41:20 2016 +0000
@@ -0,0 +1,246 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __NRF5x_GAP_H__
+#define __NRF5x_GAP_H__
+
+#ifdef YOTTA_CFG_MBED_OS
+    #include "mbed-drivers/mbed.h"
+#else
+    #include "mbed.h"
+#endif
+#ifndef YOTTA_CFG_WHITELIST_MAX_SIZE
+    #define YOTTA_CFG_WHITELIST_MAX_SIZE BLE_GAP_WHITELIST_ADDR_MAX_COUNT
+#elif YOTTA_CFG_WHITELIST_MAX_SIZE > BLE_GAP_WHITELIST_ADDR_MAX_COUNT
+    #undef YOTTA_CFG_WHITELIST_MAX_SIZE
+    #define YOTTA_CFG_WHITELIST_MAX_SIZE BLE_GAP_WHITELIST_ADDR_MAX_COUNT
+#endif
+#ifndef YOTTA_CFG_IRK_TABLE_MAX_SIZE
+    #define YOTTA_CFG_IRK_TABLE_MAX_SIZE BLE_GAP_WHITELIST_IRK_MAX_COUNT
+#elif YOTTA_CFG_IRK_TABLE_MAX_SIZE > BLE_GAP_WHITELIST_IRK_MAX_COUNT
+    #undef YOTTA_CFG_IRK_TABLE_MAX_SIZE
+    #define YOTTA_CFG_IRK_TABLE_MAX_SIZE BLE_GAP_WHITELIST_IRK_MAX_COUNT
+#endif
+#include "ble/blecommon.h"
+#include "ble.h"
+#include "ble/GapAdvertisingParams.h"
+#include "ble/GapAdvertisingData.h"
+#include "ble/Gap.h"
+#include "ble/GapScanningParams.h"
+
+#include "nrf_soc.h"
+
+extern "C" {
+#include "ble_radio_notification.h"
+}
+
+#include "btle_security.h"
+
+void radioNotificationStaticCallback(bool param);
+
+/**************************************************************************/
+/*!
+    \brief
+
+*/
+/**************************************************************************/
+class nRF5xGap : public Gap
+{
+public:
+    /* Functions that must be implemented from Gap */
+    virtual ble_error_t setAddress(AddressType_t  type,  const Address_t address);
+    virtual ble_error_t getAddress(AddressType_t *typeP, Address_t address);
+    virtual ble_error_t setAdvertisingData(const GapAdvertisingData &, const GapAdvertisingData &);
+
+    virtual uint16_t    getMinAdvertisingInterval(void) const {return GapAdvertisingParams::ADVERTISEMENT_DURATION_UNITS_TO_MS(BLE_GAP_ADV_INTERVAL_MIN);}
+    virtual uint16_t    getMinNonConnectableAdvertisingInterval(void) const {return GapAdvertisingParams::ADVERTISEMENT_DURATION_UNITS_TO_MS(BLE_GAP_ADV_NONCON_INTERVAL_MIN);}
+    virtual uint16_t    getMaxAdvertisingInterval(void) const {return GapAdvertisingParams::ADVERTISEMENT_DURATION_UNITS_TO_MS(BLE_GAP_ADV_INTERVAL_MAX);}
+
+    virtual ble_error_t startAdvertising(const GapAdvertisingParams &);
+    virtual ble_error_t stopAdvertising(void);
+    virtual ble_error_t connect(const Address_t, BLEProtocol::AddressType_t peerAddrType, const ConnectionParams_t *connectionParams, const GapScanningParams *scanParams);
+    virtual ble_error_t disconnect(Handle_t connectionHandle, DisconnectionReason_t reason);
+    virtual ble_error_t disconnect(DisconnectionReason_t reason);
+
+    virtual ble_error_t setDeviceName(const uint8_t *deviceName);
+    virtual ble_error_t getDeviceName(uint8_t *deviceName, unsigned *lengthP);
+    virtual ble_error_t setAppearance(GapAdvertisingData::Appearance appearance);
+    virtual ble_error_t getAppearance(GapAdvertisingData::Appearance *appearanceP);
+
+    virtual ble_error_t setTxPower(int8_t txPower);
+    virtual void        getPermittedTxPowerValues(const int8_t **valueArrayPP, size_t *countP);
+
+    void     setConnectionHandle(uint16_t con_handle);
+    uint16_t getConnectionHandle(void);
+
+    virtual ble_error_t getPreferredConnectionParams(ConnectionParams_t *params);
+    virtual ble_error_t setPreferredConnectionParams(const ConnectionParams_t *params);
+    virtual ble_error_t updateConnectionParams(Handle_t handle, const ConnectionParams_t *params);
+
+    virtual ble_error_t reset(void);
+
+    /*
+     * The following functions are part of the whitelisting experimental API.
+     * Therefore, this functionality can change in the near future.
+     */
+    virtual uint8_t getMaxWhitelistSize(void) const;
+    virtual ble_error_t getWhitelist(Gap::Whitelist_t &whitelistOut) const;
+    virtual ble_error_t setWhitelist(const Gap::Whitelist_t &whitelistIn);
+
+    virtual ble_error_t setAdvertisingPolicyMode(AdvertisingPolicyMode_t mode);
+    virtual ble_error_t setScanningPolicyMode(ScanningPolicyMode_t mode);
+    virtual ble_error_t setInitiatorPolicyMode(InitiatorPolicyMode_t mode);
+    virtual Gap::AdvertisingPolicyMode_t getAdvertisingPolicyMode(void) const;
+    virtual Gap::ScanningPolicyMode_t getScanningPolicyMode(void) const;
+    virtual Gap::InitiatorPolicyMode_t getInitiatorPolicyMode(void) const;
+
+    virtual ble_error_t initRadioNotification(void) {
+        if (ble_radio_notification_init(NRF_APP_PRIORITY_HIGH, NRF_RADIO_NOTIFICATION_DISTANCE_800US, radioNotificationStaticCallback) == NRF_SUCCESS) {
+            return BLE_ERROR_NONE;
+        }
+
+        return BLE_ERROR_UNSPECIFIED;
+    }
+
+/* Observer role is not supported by S110, return BLE_ERROR_NOT_IMPLEMENTED */
+#if !defined(TARGET_MCU_NRF51_16K_S110) && !defined(TARGET_MCU_NRF51_32K_S110)
+    virtual ble_error_t startRadioScan(const GapScanningParams &scanningParams);
+    virtual ble_error_t stopScan(void);
+#endif
+
+private:
+    /*
+     * Whitelisting API related structures and helper functions.
+     */
+
+    /* Policy modes set by the user. By default these are set to ignore the whitelist */
+    Gap::AdvertisingPolicyMode_t advertisingPolicyMode;
+    Gap::ScanningPolicyMode_t    scanningPolicyMode;
+
+    /* Internal representation of a whitelist */
+    uint8_t         whitelistAddressesSize;
+    ble_gap_addr_t  whitelistAddresses[YOTTA_CFG_WHITELIST_MAX_SIZE];
+
+    /*
+     * An internal function used to populate the ble_gap_whitelist_t that will be used by
+     * the SoftDevice for filtering requests. This function is needed because for the BLE
+     * API the whitelist is just a collection of keys, but for the stack it also includes
+     * the IRK table.
+     */
+    ble_error_t generateStackWhitelist(ble_gap_whitelist_t &whitelist);
+
+private:
+    bool    radioNotificationCallbackParam; /* parameter to be passed into the Timeout-generated radio notification callback. */
+    Timeout radioNotificationTimeout;
+
+    /*
+     * A helper function to post radio notification callbacks with low interrupt priority.
+     */
+    void postRadioNotificationCallback(void) {
+#ifdef YOTTA_CFG_MBED_OS
+        /*
+         * In mbed OS, all user-facing BLE events (interrupts) are posted to the
+         * MINAR scheduler to be executed as callbacks in thread mode. MINAR guards
+         * its critical sections from interrupts by acquiring CriticalSectionLock,
+         * which results in a call to sd_nvic_critical_region_enter(). Thus, it is
+         * safe to invoke MINAR APIs from interrupt context as long as those
+         * interrupts are blocked by sd_nvic_critical_region_enter().
+         *
+         * Radio notifications are a special case for the above. The Radio
+         * Notification IRQ is handled at a very high priority--higher than the
+         * level blocked by sd_nvic_critical_region_enter(). Thus Radio Notification
+         * events can preempt MINAR's critical sections. Using MINAR APIs (such as
+         * posting an event) directly in processRadioNotification() may result in a
+         * race condition ending in a hard-fault.
+         *
+         * The solution is to *not* call MINAR APIs directly from the Radio
+         * Notification handling; i.e. to do the bulk of RadioNotification
+         * processing at a reduced priority which respects MINAR's critical
+         * sections. Unfortunately, on a cortex-M0, there is no clean way to demote
+         * priority for the currently executing interrupt--we wouldn't want to
+         * demote the radio notification handling anyway because it is sensitive to
+         * timing, and the system expects to finish this handling very quickly. The
+         * workaround is to employ a Timeout to trigger
+         * postRadioNotificationCallback() after a very short delay (~0 us) and post
+         * the MINAR callback that context.
+         *
+         * !!!WARNING!!! Radio notifications are very time critical events. The
+         * current solution is expected to work under the assumption that
+         * postRadioNotificationCalback() will be executed BEFORE the next radio
+         * notification event is generated.
+         */
+        minar::Scheduler::postCallback(
+            mbed::util::FunctionPointer1<void, bool>(&radioNotificationCallback, &FunctionPointerWithContext<bool>::call).bind(radioNotificationCallbackParam)
+        );
+#else
+        /*
+         * In mbed classic, all user-facing BLE events execute callbacks in interrupt
+         * mode. Radio Notifications are a special case because its IRQ is handled at
+         * a very high priority. Thus Radio Notification events can preempt other
+         * operations that require interaction with the SoftDevice such as advertising
+         * payload updates and changing the Gap state. Therefore, executing a Radio
+         * Notification callback directly from processRadioNotification() may result
+         * in a race condition ending in a hard-fault.
+         *
+         * The solution is to *not* execute the Radio Notification callback directly
+         * from the Radio Notification handling; i.e. to do the bulk of the
+         * Radio Notification processing at a reduced priority. Unfortunately, on a
+         * cortex-M0, there is no clean way to demote priority for the currently
+         * executing interrupt--we wouldn't want to demote the radio notification
+         * handling anyway because it is sensitive to timing, and the system expects
+         * to finish this handling very quickly. The workaround is to employ a Timeout
+         * to trigger postRadioNotificationCallback() after a very short delay (~0 us)
+         * and execute the callback in that context.
+         *
+         * !!!WARNING!!! Radio notifications are very time critical events. The
+         * current solution is expected to work under the assumption that
+         * postRadioNotificationCalback() will be executed BEFORE the next radio
+         * notification event is generated.
+         */
+        radioNotificationCallback.call(radioNotificationCallbackParam);
+#endif /* #ifdef YOTTA_CFG_MBED_OS */
+    }
+
+    /**
+     * A helper function to process radio-notification events; to be called internally.
+     * @param param [description]
+     */
+    void processRadioNotificationEvent(bool param) {
+        radioNotificationCallbackParam = param;
+        radioNotificationTimeout.attach_us(this, &nRF5xGap::postRadioNotificationCallback, 0);
+    }
+    friend void radioNotificationStaticCallback(bool param); /* allow invocations of processRadioNotificationEvent() */
+
+private:
+    uint16_t m_connectionHandle;
+
+    /*
+     * Allow instantiation from nRF5xn when required.
+     */
+    friend class nRF5xn;
+
+    nRF5xGap() :
+        advertisingPolicyMode(Gap::ADV_POLICY_IGNORE_WHITELIST),
+        scanningPolicyMode(Gap::SCAN_POLICY_IGNORE_WHITELIST),
+        whitelistAddressesSize(0) {
+        m_connectionHandle = BLE_CONN_HANDLE_INVALID;
+    }
+
+    nRF5xGap(nRF5xGap const &);
+    void operator=(nRF5xGap const &);
+};
+
+#endif // ifndef __NRF5x_GAP_H__
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