Bluetooth: controller: Move common LLL from vendor file

Split lll_prepare and lll_resume from Nordic LLL to common file for
reuse by all vendors. The split also supports new JIT Scheduling by
defining a common place to calculate event prepare priority.

The module may also house other common parts of the LLL currently
re-implemented identically by vendors.

Signed-off-by: Morten Priess <mtpr@oticon.com>

subsys/bluetooth/controller/CMakeLists.txt

@@ -21,6 +21,7 @@ zephyr_library_sources_ifdef(
 if(CONFIG_BT_LL_SW_SPLIT)
   zephyr_library_sources(
     ll_sw/ull.c
+    ll_sw/lll_common.c
     )
   if(CONFIG_BT_BROADCASTER)
     zephyr_library_sources(

subsys/bluetooth/controller/ll_sw/lll.h

@@ -419,3 +419,13 @@ void ull_rx_sched(void);
 void ull_rx_sched_done(void);
 void *ull_event_done_extra_get(void);
 void *ull_event_done(void *param);
+
+int lll_prepare(lll_is_abort_cb_t is_abort_cb,
+		lll_abort_cb_t abort_cb,
+		lll_prepare_cb_t prepare_cb, int8_t event_prio,
+		struct lll_prepare_param *prepare_param);
+int lll_resume_enqueue(lll_prepare_cb_t resume_cb, int resume_prio);
+int lll_prepare_resolve(lll_is_abort_cb_t is_abort_cb, lll_abort_cb_t abort_cb,
+			lll_prepare_cb_t prepare_cb,  int prio,
+			struct lll_prepare_param *prepare_param,
+			uint8_t is_resume, uint8_t is_dequeue);

subsys/bluetooth/controller/ll_sw/lll_common.c

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2021 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <errno.h>
+#include <zephyr/types.h>
+#include <device.h>
+
+#include "util/mem.h"
+#include "util/memq.h"
+
+#include "lll.h"
+
+#define BT_DBG_ENABLED IS_ENABLED(CONFIG_BT_DEBUG_HCI_DRIVER)
+#define LOG_MODULE_NAME bt_ctlr_lll_common
+#include "common/log.h"
+#include "hal/debug.h"
+
+/**
+ * @brief Common entry point for LLL event prepare invocations from ULL.
+ *
+ * This function will resolve the event priority and invoke the LLL
+ * lll_prepare_resolve, which decides if event should be programmed in
+ * the radio via the prepare callback function, or queued in the prepare
+ * pipeline.
+ *
+ * @param is_abort_cb   Callback for checking if event is aborted
+ * @param abort_cb      Callback for aborting event
+ * @param prepare_cb    Callback for event prepare
+ * @param event_prio    Priority of event [-128..127]
+ * @param prepare_param Prepare data
+ *
+ * @return 0: Prepare was successfully completed
+ *	   1: TICKER_STATUS_FAILURE: Preemption ticker stop error
+ *	   2: TICKER_STATUS_BUSY: Preemption ticker stop error
+ *	   -EINPROGRESS: Event already in progress and prepare was queued
+ */
+int lll_prepare(lll_is_abort_cb_t is_abort_cb, lll_abort_cb_t abort_cb,
+		lll_prepare_cb_t prepare_cb, int8_t event_prio,
+		struct lll_prepare_param *prepare_param)
+{
+	/* TODO: Calculate priority */
+
+	return lll_prepare_resolve(is_abort_cb, abort_cb, prepare_cb,
+				   prepare_param, 0, 0);
+}
+
+void lll_resume(void *param)
+{
+	struct lll_event *next;
+	int ret;
+
+	next = param;
+	ret = lll_prepare_resolve(next->is_abort_cb, next->abort_cb,
+				  next->prepare_cb, &next->prepare_param,
+				  next->is_resume, 1);
+	LL_ASSERT(!ret || ret == -EINPROGRESS);
+}

subsys/bluetooth/controller/ll_sw/nordic/lll/lll.c

@@ -65,10 +65,6 @@ static int init_reset(void);
 #if defined(CONFIG_BT_CTLR_LOW_LAT_ULL_DONE)
 static inline void done_inc(void);
 #endif /* CONFIG_BT_CTLR_LOW_LAT_ULL_DONE */
-static int prepare(lll_is_abort_cb_t is_abort_cb, lll_abort_cb_t abort_cb,
-		   lll_prepare_cb_t prepare_cb, int prio,
-		   struct lll_prepare_param *prepare_param,
-		   uint8_t is_resume, uint8_t is_dequeue);
 static int resume_enqueue(lll_prepare_cb_t resume_cb, int resume_prio);
 static void isr_race(void *param);
 
@@ -246,25 +242,6 @@ int lll_reset(void)
 	return 0;
 }
 
-int lll_prepare(lll_is_abort_cb_t is_abort_cb, lll_abort_cb_t abort_cb,
-		lll_prepare_cb_t prepare_cb, int prio,
-		struct lll_prepare_param *prepare_param)
-{
-	return prepare(is_abort_cb, abort_cb, prepare_cb, prio, prepare_param,
-		       0, 0);
-}
-
-void lll_resume(void *param)
-{
-	struct lll_event *next;
-	int ret;
-
-	next = param;
-	ret = prepare(next->is_abort_cb, next->abort_cb, next->prepare_cb,
-		      next->prio, &next->prepare_param, next->is_resume, 1);
-	LL_ASSERT(!ret || ret == -EINPROGRESS);
-}
-
 void lll_disable(void *param)
 {
 	/* LLL disable of current event, done is generated */
@@ -618,7 +595,7 @@ static inline bool is_done_sync(void)
 #endif /* !CONFIG_BT_CTLR_LOW_LAT_ULL_DONE */
 }
 
-static int prepare(lll_is_abort_cb_t is_abort_cb, lll_abort_cb_t abort_cb,
+int lll_prepare_resolve(lll_is_abort_cb_t is_abort_cb, lll_abort_cb_t abort_cb,
 			lll_prepare_cb_t prepare_cb, int prio,
 			struct lll_prepare_param *prepare_param,
 			uint8_t is_resume, uint8_t is_dequeue)

subsys/bluetooth/controller/ll_sw/nordic/lll/lll_internal.h

@@ -4,9 +4,6 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-int lll_prepare(lll_is_abort_cb_t is_abort_cb, lll_abort_cb_t abort_cb,
-		lll_prepare_cb_t prepare_cb, int prio,
-		struct lll_prepare_param *prepare_param);
 int lll_prepare_done(void *param);
 int lll_done(void *param);
 bool lll_is_done(void *param);