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pigweed / third_party / github / zephyrproject-rtos / zephyr / 6d67a81e1971da9cfbf6bc55c5998e2f5e837d5c / . / subsys / bluetooth / controller / ll_sw / isoal.c
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/*
* Copyright (c) 2021 Demant
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <string.h>
#include <zephyr/types.h>
#include <sys/types.h>
#include <zephyr/toolchain.h>
#include <zephyr/sys/util.h>
#include <zephyr/kernel.h>
#include <zephyr/bluetooth/bluetooth.h>
#include "util/memq.h"
#include "pdu.h"
#include "ll.h"
#include "lll.h"
#include "lll_conn_iso.h"
#include "lll_iso_tx.h"
#include "isoal.h"
#include "ull_iso_types.h"
#define LOG_MODULE_NAME bt_ctlr_isoal
#include "common/log.h"
#include "hal/debug.h"
/** Allocation state */
typedef uint8_t isoal_alloc_state_t;
#define ISOAL_ALLOC_STATE_FREE ((isoal_alloc_state_t) 0x00)
#define ISOAL_ALLOC_STATE_TAKEN ((isoal_alloc_state_t) 0x01)
struct
{
#if defined(CONFIG_BT_CTLR_SYNC_ISO) || defined(CONFIG_BT_CTLR_CONN_ISO)
isoal_alloc_state_t sink_allocated[CONFIG_BT_CTLR_ISOAL_SINKS];
struct isoal_sink sink_state[CONFIG_BT_CTLR_ISOAL_SINKS];
#endif /* CONFIG_BT_CTLR_SYNC_ISO || CONFIG_BT_CTLR_CONN_ISO */
#if defined(CONFIG_BT_CTLR_ADV_ISO) || defined(CONFIG_BT_CTLR_CONN_ISO)
isoal_alloc_state_t source_allocated[CONFIG_BT_CTLR_ISOAL_SOURCES];
struct isoal_source source_state[CONFIG_BT_CTLR_ISOAL_SOURCES];
#endif /* CONFIG_BT_CTLR_ADV_ISO || CONFIG_BT_CTLR_CONN_ISO */
} isoal_global;
/**
* @brief Internal reset
* Zero-init entire ISO-AL state
*/
static isoal_status_t isoal_init_reset(void)
{
memset(&isoal_global, 0, sizeof(isoal_global));
return ISOAL_STATUS_OK;
}
/**
* @brief Initialize ISO-AL
*/
isoal_status_t isoal_init(void)
{
isoal_status_t err = ISOAL_STATUS_OK;
err = isoal_init_reset();
return err;
}
/** Clean up and reinitialize */
isoal_status_t isoal_reset(void)
{
isoal_status_t err = ISOAL_STATUS_OK;
err = isoal_init_reset();
return err;
}
#if defined(CONFIG_BT_CTLR_SYNC_ISO) || defined(CONFIG_BT_CTLR_CONN_ISO)
/**
* @brief Find free sink from statically-sized pool and allocate it
* @details Implemented as linear search since pool is very small
*
* @param hdl[out] Handle to sink
* @return ISOAL_STATUS_OK if we could allocate; otherwise ISOAL_STATUS_ERR_SINK_ALLOC
*/
static isoal_status_t isoal_sink_allocate(isoal_sink_handle_t *hdl)
{
isoal_sink_handle_t i;
/* Very small linear search to find first free */
for (i = 0; i < CONFIG_BT_CTLR_ISOAL_SINKS; i++) {
if (isoal_global.sink_allocated[i] == ISOAL_ALLOC_STATE_FREE) {
isoal_global.sink_allocated[i] = ISOAL_ALLOC_STATE_TAKEN;
*hdl = i;
return ISOAL_STATUS_OK;
}
}
return ISOAL_STATUS_ERR_SINK_ALLOC; /* All entries were taken */
}
/**
* @brief Mark a sink as being free to allocate again
* @param hdl[in] Handle to sink
*/
static void isoal_sink_deallocate(isoal_sink_handle_t hdl)
{
isoal_global.sink_allocated[hdl] = ISOAL_ALLOC_STATE_FREE;
}
/**
* @brief Create a new sink
*
* @param handle[in] Connection handle
* @param role[in] Peripheral, Central or Broadcast
* @param framed[in] Framed case
* @param burst_number[in] Burst Number
* @param flush_timeout[in] Flush timeout
* @param sdu_interval[in] SDU interval
* @param iso_interval[in] ISO interval
* @param stream_sync_delay[in] CIS sync delay
* @param group_sync_delay[in] CIG sync delay
* @param sdu_alloc[in] Callback of SDU allocator
* @param sdu_emit[in] Callback of SDU emitter
* @param sdu_write[in] Callback of SDU byte writer
* @param hdl[out] Handle to new sink
*
* @return ISOAL_STATUS_OK if we could create a new sink; otherwise ISOAL_STATUS_ERR_SINK_ALLOC
*/
isoal_status_t isoal_sink_create(
uint16_t handle,
uint8_t role,
uint8_t framed,
uint8_t burst_number,
uint8_t flush_timeout,
uint32_t sdu_interval,
uint16_t iso_interval,
uint32_t stream_sync_delay,
uint32_t group_sync_delay,
isoal_sink_sdu_alloc_cb sdu_alloc,
isoal_sink_sdu_emit_cb sdu_emit,
isoal_sink_sdu_write_cb sdu_write,
isoal_sink_handle_t *hdl)
{
uint32_t iso_interval_us;
isoal_status_t err;
/* ISO interval in units of time requires the integer (iso_interval)
* to be multiplied by 1250us.
*/
iso_interval_us = iso_interval * ISO_INT_UNIT_US;
/* Allocate a new sink */
err = isoal_sink_allocate(hdl);
if (err) {
return err;
}
struct isoal_sink_session *session = &isoal_global.sink_state[*hdl].session;
session->handle = handle;
session->framed = framed;
/* Todo: Next section computing various constants, should potentially be a
* function in itself as a number of the dependencies could be changed while
* a connection is active.
*/
session->pdus_per_sdu = (burst_number * sdu_interval) /
iso_interval_us;
/* Computation of transport latency (constant part)
*
* Unframed case:
*
* C->P: SDU_Synchronization_Reference =
* CIS reference anchor point + CIS_Sync_Delay + (FT_C_To_P - 1) * ISO_Interval
*
* P->C: SDU_Synchronization_Reference =
* CIS reference anchor point + CIS_Sync_Delay - CIG_Sync_Delay -
* ((ISO_Interval / SDU interval)-1) * SDU interval
*
* BIS: SDU_Synchronization_Reference =
* BIG reference anchor point + BIG_Sync_Delay
*
* Framed case:
*
* C->P: SDU_Synchronization_Reference =
* CIS Reference Anchor point +
* CIS_Sync_Delay + SDU_Interval_C_To_P + FT_C_To_P * ISO_Interval -
* Time_Offset
*
* P->C: synchronization reference SDU = CIS reference anchor point +
* CIS_Sync_Delay - CIG_Sync_Delay - Time_Offset
*
* BIS: SDU_Synchronization_Reference =
* BIG reference anchor point +
* BIG_Sync_Delay + SDU_interval + ISO_Interval - Time_Offset.
*/
if (role == BT_CONN_ROLE_PERIPHERAL) {
isoal_global.sink_state[*hdl].session.latency_unframed =
stream_sync_delay + ((flush_timeout - 1) * iso_interval_us);
isoal_global.sink_state[*hdl].session.latency_framed =
stream_sync_delay + sdu_interval + (flush_timeout * iso_interval_us);
} else if (role == BT_CONN_ROLE_CENTRAL) {
isoal_global.sink_state[*hdl].session.latency_unframed =
stream_sync_delay - group_sync_delay -
(((iso_interval_us / sdu_interval) - 1) * iso_interval_us);
isoal_global.sink_state[*hdl].session.latency_framed =
stream_sync_delay - group_sync_delay;
} else if (role == BT_ROLE_BROADCAST) {
isoal_global.sink_state[*hdl].session.latency_unframed =
group_sync_delay;
isoal_global.sink_state[*hdl].session.latency_framed =
group_sync_delay + sdu_interval + iso_interval_us;
} else {
LL_ASSERT(0);
}
/* Remember the platform-specific callbacks */
session->sdu_alloc = sdu_alloc;
session->sdu_emit = sdu_emit;
session->sdu_write = sdu_write;
/* Initialize running seq number to zero */
session->seqn = 0;
return err;
}
/**
* @brief Get reference to configuration struct
*
* @param hdl[in] Handle to new sink
* @return Reference to parameter struct, to be configured by caller
*/
struct isoal_sink_config *isoal_get_sink_param_ref(isoal_sink_handle_t hdl)
{
LL_ASSERT(isoal_global.sink_allocated[hdl] == ISOAL_ALLOC_STATE_TAKEN);
return &isoal_global.sink_state[hdl].session.param;
}
/**
* @brief Atomically enable latch-in of packets and SDU production
* @param hdl[in] Handle of existing instance
*/
void isoal_sink_enable(isoal_sink_handle_t hdl)
{
/* Reset bookkeeping state */
memset(&isoal_global.sink_state[hdl].sdu_production, 0,
sizeof(isoal_global.sink_state[hdl].sdu_production));
/* Atomically enable */
isoal_global.sink_state[hdl].sdu_production.mode = ISOAL_PRODUCTION_MODE_ENABLED;
}
/**
* @brief Atomically disable latch-in of packets and SDU production
* @param hdl[in] Handle of existing instance
*/
void isoal_sink_disable(isoal_sink_handle_t hdl)
{
/* Atomically disable */
isoal_global.sink_state[hdl].sdu_production.mode = ISOAL_PRODUCTION_MODE_DISABLED;
}
/**
* @brief Disable and deallocate existing sink
* @param hdl[in] Handle of existing instance
*/
void isoal_sink_destroy(isoal_sink_handle_t hdl)
{
/* Atomic disable */
isoal_sink_disable(hdl);
/* Permit allocation anew */
isoal_sink_deallocate(hdl);
}
/* Obtain destination SDU */
static isoal_status_t isoal_rx_allocate_sdu(struct isoal_sink *sink,
const struct isoal_pdu_rx *pdu_meta)
{
struct isoal_sink_session *session;
struct isoal_sdu_production *sp;
struct isoal_sdu_produced *sdu;
isoal_status_t err;
err = ISOAL_STATUS_OK;
session = &sink->session;
sp = &sink->sdu_production;
sdu = &sp->sdu;
/* Allocate a SDU if the previous was filled (thus sent) */
const bool sdu_complete = (sp->sdu_available == 0);
if (sdu_complete) {
/* Allocate new clean SDU buffer */
err = session->sdu_alloc(
sink,
pdu_meta, /* [in] PDU origin may determine buffer */
&sdu->contents /* [out] Updated with pointer and size */
);
if (err == ISOAL_STATUS_OK) {
sp->sdu_allocated = true;
}
/* Nothing has been written into buffer yet */
sp->sdu_written = 0;
sp->sdu_available = sdu->contents.size;
LL_ASSERT(sdu->contents.size > 0);
/* Get seq number from session counter */
sdu->seqn = session->seqn;
}
return err;
}
static isoal_status_t isoal_rx_try_emit_sdu(struct isoal_sink *sink, bool end_of_sdu)
{
struct isoal_sdu_production *sp;
struct isoal_sdu_produced *sdu;
isoal_status_t err;
err = ISOAL_STATUS_OK;
sp = &sink->sdu_production;
sdu = &sp->sdu;
/* Emit a SDU */
const bool sdu_complete = (sp->sdu_available == 0) || end_of_sdu;
if (end_of_sdu) {
sp->sdu_available = 0;
}
if (sdu_complete) {
uint8_t next_state = BT_ISO_START;
switch (sp->sdu_state) {
case BT_ISO_START:
if (end_of_sdu) {
sp->sdu_state = BT_ISO_SINGLE;
next_state = BT_ISO_START;
} else {
sp->sdu_state = BT_ISO_START;
next_state = BT_ISO_CONT;
}
break;
case BT_ISO_CONT:
if (end_of_sdu) {
sp->sdu_state = BT_ISO_END;
next_state = BT_ISO_START;
} else {
sp->sdu_state = BT_ISO_CONT;
next_state = BT_ISO_CONT;
}
break;
}
sdu->status = sp->sdu_status;
struct isoal_sink_session *session = &sink->session;
err = session->sdu_emit(sink, sdu);
sp->sdu_allocated = false;
/* update next state */
sink->sdu_production.sdu_state = next_state;
}
return err;
}
static isoal_status_t isoal_rx_append_to_sdu(struct isoal_sink *sink,
const struct isoal_pdu_rx *pdu_meta,
uint8_t offset,
uint8_t length,
bool is_end_fragment,
bool is_padding)
{
isoal_pdu_len_t packet_available;
const uint8_t *pdu_payload;
bool handle_error_case;
isoal_status_t err;
/* Might get an empty packed due to errors, we will need to terminate
* and send something up anyhow
*/
packet_available = length;
handle_error_case = (is_end_fragment && (packet_available == 0));
pdu_payload = pdu_meta->pdu->payload + offset;
LL_ASSERT(pdu_payload);
/* While there is something left of the packet to consume */
err = ISOAL_STATUS_OK;
while ((packet_available > 0) || handle_error_case) {
isoal_status_t err_alloc;
struct isoal_sdu_production *sp;
struct isoal_sdu_produced *sdu;
err_alloc = ISOAL_STATUS_OK;
if (!is_padding) {
/* A new SDU should only be allocated if the current is
* not padding. Covers a situation where the end
* fragment was not received.
*/
err_alloc = isoal_rx_allocate_sdu(sink, pdu_meta);
}
sp = &sink->sdu_production;
sdu = &sp->sdu;
err |= err_alloc;
/*
* For this SDU we can only consume of packet, bounded by:
* - What can fit in the destination SDU.
* - What remains of the packet.
*/
const size_t consume_len = MIN(
packet_available,
sp->sdu_available
);
if (consume_len > 0) {
const struct isoal_sink_session *session = &sink->session;
err |= session->sdu_write(sdu->contents.dbuf,
pdu_payload,
consume_len);
pdu_payload += consume_len;
sp->sdu_written += consume_len;
sp->sdu_available -= consume_len;
packet_available -= consume_len;
}
bool end_of_sdu = (packet_available == 0) && is_end_fragment;
isoal_status_t err_emit = ISOAL_STATUS_OK;
if (sp->sdu_allocated) {
/* SDU should be emitted only if it was allocated */
err_emit = isoal_rx_try_emit_sdu(sink, end_of_sdu);
}
handle_error_case = false;
err |= err_emit;
}
return err;
}
/**
* @brief Consume an unframed PDU: Copy contents into SDU(s) and emit to a sink
* @details Destination sink may have an already partially built SDU
*
* @param sink[in,out] Destination sink with bookkeeping state
* @param pdu_meta[out] PDU with meta information (origin, timing, status)
*
* @return Status
*/
static isoal_status_t isoal_rx_unframed_consume(struct isoal_sink *sink,
const struct isoal_pdu_rx *pdu_meta)
{
struct isoal_sink_session *session;
struct isoal_sdu_production *sp;
struct node_rx_iso_meta *meta;
struct pdu_iso *pdu;
bool end_of_packet;
uint8_t next_state;
isoal_status_t err;
bool pdu_padding;
uint8_t length;
bool last_pdu;
bool pdu_err;
bool seq_err;
uint8_t llid;
sp = &sink->sdu_production;
session = &sink->session;
meta = pdu_meta->meta;
pdu = pdu_meta->pdu;
err = ISOAL_STATUS_OK;
next_state = ISOAL_START;
/* If status is not ISOAL_PDU_STATUS_VALID, length and LLID cannot be trusted */
llid = pdu_meta->pdu->ll_id;
pdu_err = (pdu_meta->meta->status != ISOAL_PDU_STATUS_VALID);
length = pdu_meta->pdu->length;
/* A zero length PDU with LLID 0b01 (PDU_BIS_LLID_START_CONTINUE) would be a padding PDU.
* However if there are errors in the PDU, it could be an incorrectly receive non-padding
* PDU. Therefore only consider a PDU with errors as padding if received after the end
* fragment is seen when padding PDUs are expected.
*/
pdu_padding = (length == 0) && (llid == PDU_BIS_LLID_START_CONTINUE) &&
(!pdu_err || sp->fsm == ISOAL_ERR_SPOOL);
seq_err = (meta->payload_number != (sp->prev_pdu_id+1));
/* If there are no buffers available, the PDUs received by the ISO-AL
* may not be in sequence even though this is expected for unframed rx.
* It would be necessary to exit the ISOAL_ERR_SPOOL state as the PDU
* count and as a result the last_pdu detection is no longer reliable.
*/
if (sp->fsm == ISOAL_ERR_SPOOL) {
if ((!pdu_err && !seq_err &&
/* Previous sequence error should have move to the
* ISOAL_ERR_SPOOL state and emitted the SDU in production. No
* PDU error so LLID and length are reliable and no sequence
* error so this PDU is the next in order.
*/
((sp->prev_pdu_is_end || sp->prev_pdu_is_padding) &&
((llid == PDU_BIS_LLID_START_CONTINUE && length > 0) ||
(llid == PDU_BIS_LLID_COMPLETE_END && length == 0))))
/* Detected a start of a new SDU as the last PDU was an end
* fragment or padding and the current is the start of a new SDU
* (either filled or zero length). Move to ISOAL_START
* immediately.
*/
|| (meta->payload_number % session->pdus_per_sdu == 0)) {
/* Based on the payload number, this should be the start
* of a new SDU.
*/
sp->fsm = ISOAL_START;
}
}
if (sp->fsm == ISOAL_START) {
struct isoal_sdu_produced *sdu;
uint32_t anchorpoint;
uint32_t latency;
sp->sdu_status = ISOAL_SDU_STATUS_VALID;
sp->sdu_state = BT_ISO_START;
sp->pdu_cnt = 1;
session->seqn++;
seq_err = false;
/* Todo: anchorpoint must be reference anchor point, should be fixed in LL */
anchorpoint = meta->timestamp;
latency = session->latency_unframed;
sdu = &sp->sdu;
sdu->timestamp = anchorpoint + latency;
} else {
sp->pdu_cnt++;
}
last_pdu = (sp->pdu_cnt == session->pdus_per_sdu);
end_of_packet = (llid == PDU_BIS_LLID_COMPLETE_END) || last_pdu || pdu_err;
switch (sp->fsm) {
case ISOAL_START:
case ISOAL_CONTINUE:
if (pdu_err || seq_err) {
/* PDU contains errors */
if (last_pdu) {
/* Last PDU all done */
next_state = ISOAL_START;
} else {
next_state = ISOAL_ERR_SPOOL;
}
} else if (llid == PDU_BIS_LLID_START_CONTINUE) {
/* PDU contains a continuation (neither start of end) fragment of SDU */
if (last_pdu) {
/* last pdu in sdu, but end fragment not seen, emit with error */
next_state = ISOAL_START;
} else {
next_state = ISOAL_CONTINUE;
}
} else if (llid == PDU_BIS_LLID_COMPLETE_END) {
/* PDU contains end fragment of a fragmented SDU */
if (last_pdu) {
/* Last PDU all done */
next_state = ISOAL_START;
} else {
/* Padding after end fragment to follow */
next_state = ISOAL_ERR_SPOOL;
}
} else {
/* Unsupported case */
err = ISOAL_STATUS_ERR_UNSPECIFIED;
BT_ERR("Invalid unframed LLID (%d)", llid);
LL_ASSERT(0);
}
break;
case ISOAL_ERR_SPOOL:
/* State assumes that at end fragment or err has been seen,
* now just consume the rest
*/
if (last_pdu) {
/* Last padding seen, restart */
next_state = ISOAL_START;
} else {
next_state = ISOAL_ERR_SPOOL;
}
break;
}
/* Update error state */
/* Prioritisation:
* (1) Sequence Error should set the ISOAL_SDU_STATUS_LOST_DATA status
* as data is missing and this will trigger the HCI to discard any
* data received.
*
* BT Core V5.3 : Vol 4 HCI I/F : Part G HCI Func. Spec.:
* 5.4.5 HCI ISO Data packets
* If Packet_Status_Flag equals 0b10 then PB_Flag shall equal 0b10.
* When Packet_Status_Flag is set to 0b10 in packets from the Controller to the
* Host, there is no data and ISO_SDU_Length shall be set to zero.
*
* (2) Any error status received from the LL via the PDU status should
* set the relevant error conditions.
*
* (3) Missing end fragment handling.
*/
if (seq_err) {
sp->sdu_status |= ISOAL_SDU_STATUS_LOST_DATA;
} else if (pdu_err && !pdu_padding) {
sp->sdu_status |= meta->status;
} else if (last_pdu && (llid != PDU_BIS_LLID_COMPLETE_END) &&
(sp->fsm != ISOAL_ERR_SPOOL)) {
/* END fragment never seen */
sp->sdu_status |= ISOAL_SDU_STATUS_ERRORS;
}
/* Append valid PDU to SDU */
if (sp->fsm != ISOAL_ERR_SPOOL && (!pdu_padding || end_of_packet)) {
err |= isoal_rx_append_to_sdu(sink, pdu_meta, 0,
length, end_of_packet,
pdu_padding);
}
/* Update next state */
sp->fsm = next_state;
sp->prev_pdu_id = meta->payload_number;
sp->prev_pdu_is_end = !pdu_err && llid == PDU_BIS_LLID_COMPLETE_END;
sp->prev_pdu_is_padding = !pdu_err && pdu_padding;
return err;
}
/**
* @brief Consume a framed PDU: Copy contents into SDU(s) and emit to a sink
* @details Destination sink may have an already partially built SDU
*
* @param sink[in,out] Destination sink with bookkeeping state
* @param pdu_meta[out] PDU with meta information (origin, timing, status)
*
* @return Status
*/
static isoal_status_t isoal_rx_framed_consume(struct isoal_sink *sink,
const struct isoal_pdu_rx *pdu_meta)
{
struct isoal_sink_session *session;
struct isoal_sdu_production *sp;
struct isoal_sdu_produced *sdu;
struct pdu_iso_sdu_sh *seg_hdr;
struct node_rx_iso_meta *meta;
uint32_t anchorpoint;
uint8_t *end_of_pdu;
uint32_t timeoffset;
isoal_status_t err;
uint8_t next_state;
uint32_t timestamp;
uint32_t latency;
bool pdu_padding;
bool pdu_err;
bool seq_err;
sp = &sink->sdu_production;
session = &sink->session;
meta = pdu_meta->meta;
sdu = &sp->sdu;
err = ISOAL_STATUS_OK;
next_state = ISOAL_START;
pdu_err = (pdu_meta->meta->status != ISOAL_PDU_STATUS_VALID);
pdu_padding = (pdu_meta->pdu->length == 0);
if (sp->fsm == ISOAL_START) {
seq_err = false;
} else {
seq_err = (meta->payload_number != (sp->prev_pdu_id + 1));
}
end_of_pdu = ((uint8_t *) pdu_meta->pdu->payload) + pdu_meta->pdu->length - 1;
seg_hdr = (struct pdu_iso_sdu_sh *) pdu_meta->pdu->payload;
if (pdu_err || seq_err) {
/* When one or more ISO Data PDUs are not received, the receiving device may
* discard all SDUs affected by the missing PDUs. Any partially received SDU
* may also be discarded.
*/
next_state = ISOAL_ERR_SPOOL;
/* This maps directly to the HCI ISO Data packet Packet_Status_Flag by way of the
* sdu_status in the SDU emitted.
* BT Core V5.3 : Vol 4 HCI I/F : Part G HCI Func. Spec.:
* 5.4.5 HCI ISO Data packets : Table 5.2 :
* Packet_Status_Flag (in packets sent by the Controller)
* 0b00 Valid data. The complete SDU was received correctly.
* 0b01 Possibly invalid data. The contents of the ISO_SDU_Fragment may contain
* errors or part of the SDU may be missing. This is reported as "data with
* possible errors".
* 0b10 Part(s) of the SDU were not received correctly. This is reported as
* "lost data".
*/
if (seq_err) {
sp->sdu_status |= ISOAL_SDU_STATUS_LOST_DATA;
} else if (pdu_err) {
sp->sdu_status |= meta->status;
}
if (sp->fsm == ISOAL_START) {
/* Sequence number shall be incremented even if an error
* occurs at the beginning.
*/
session->seqn++;
}
/* Flush current SDU with error if any */
err |= isoal_rx_append_to_sdu(sink, pdu_meta, 0, 0, true, false);
/* Skip searching this PDU */
seg_hdr = NULL;
/* Update next state */
sink->sdu_production.fsm = next_state;
}
if (pdu_padding) {
/* Skip searching this PDU */
seg_hdr = NULL;
}
while (seg_hdr) {
bool append = true;
const uint8_t sc = seg_hdr->sc;
const uint8_t cmplt = seg_hdr->cmplt;
if (sp->fsm == ISOAL_START) {
sp->sdu_status = ISOAL_SDU_STATUS_VALID;
sp->sdu_state = BT_ISO_START;
session->seqn++;
}
switch (sp->fsm) {
case ISOAL_START:
timeoffset = seg_hdr->timeoffset;
anchorpoint = meta->timestamp;
latency = session->latency_framed;
timestamp = anchorpoint + latency - timeoffset;
if (!sc && !cmplt) {
/* The start of a new SDU, where not all SDU data is included in
* the current PDU, and additional PDUs are required to complete
* the SDU.
*/
sdu->timestamp = timestamp;
next_state = ISOAL_CONTINUE;
} else if (!sc && cmplt) {
/* The start of a new SDU that contains the full SDU data in the
* current PDU.
*/
sdu->timestamp = timestamp;
next_state = ISOAL_START;
} else {
/* Unsupported case */
err = ISOAL_STATUS_ERR_UNSPECIFIED;
}
break;
case ISOAL_CONTINUE:
if (sc && !cmplt) {
/* The continuation of a previous SDU. The SDU payload is appended
* to the previous data and additional PDUs are required to
* complete the SDU.
*/
next_state = ISOAL_CONTINUE;
} else if (sc && cmplt) {
/* The continuation of a previous SDU.
* Frame data is appended to previously received SDU data and
* completes in the current PDU.
*/
next_state = ISOAL_START;
} else {
/* Unsupported case */
err = ISOAL_STATUS_ERR_UNSPECIFIED;
}
break;
case ISOAL_ERR_SPOOL:
/* In error state, search for valid next start of SDU */
timeoffset = seg_hdr->timeoffset;
anchorpoint = meta->timestamp;
latency = session->latency_framed;
timestamp = anchorpoint + latency - timeoffset;
if (!sc && !cmplt) {
/* The start of a new SDU, where not all SDU data is included in
* the current PDU, and additional PDUs are required to complete
* the SDU.
*/
sdu->timestamp = timestamp;
next_state = ISOAL_CONTINUE;
} else if (!sc && cmplt) {
/* The start of a new SDU that contains the full SDU data in the
* current PDU.
*/
sdu->timestamp = timestamp;
next_state = ISOAL_START;
} else {
/* Start not found yet, stay in Error state */
append = false;
next_state = ISOAL_ERR_SPOOL;
}
/* TODO: Confirm if the sequence number must be updated even for an SDU
* with errors.
* BT Core V5.3 : Vol 6 Low Energy Controller : Part G IS0-AL:
* 2 ISOAL Features :
* The sequence number shall be incremented for each SDU_Interval,
* whether or not an SDU was received from or sent to the upper layer.
*/
if (next_state != ISOAL_ERR_SPOOL) {
/* While in the Error state, received a valid start of the next SDU,
* so SDU status and sequence number should be updated.
*/
sp->sdu_status = ISOAL_SDU_STATUS_VALID;
/* sp->sdu_state will be set by next_state decided above */
session->seqn++;
}
break;
}
if (append) {
/* Calculate offset of first payload byte from SDU based on assumption
* of No time_offset in header
*/
uint8_t offset = ((uint8_t *) seg_hdr) + PDU_ISO_SEG_HDR_SIZE -
pdu_meta->pdu->payload;
uint8_t length = seg_hdr->length;
if (!sc) {
/* time_offset included in header, don't copy offset field to SDU */
offset = offset + PDU_ISO_SEG_TIMEOFFSET_SIZE;
length = length - PDU_ISO_SEG_TIMEOFFSET_SIZE;
}
/* Todo: check if effective len=0 what happens then?
* We should possibly be able to send empty packets with only time stamp
*/
err |= isoal_rx_append_to_sdu(sink, pdu_meta, offset, length, cmplt, false);
}
/* Update next state */
sp->fsm = next_state;
/* Find next segment header, set to null if past end of PDU */
seg_hdr = (struct pdu_iso_sdu_sh *) (((uint8_t *) seg_hdr) +
seg_hdr->length + PDU_ISO_SEG_HDR_SIZE);
if (((uint8_t *) seg_hdr) > end_of_pdu) {
seg_hdr = NULL;
}
}
sp->prev_pdu_id = meta->payload_number;
return err;
}
/**
* @brief Deep copy a PDU, recombine into SDU(s)
* @details Recombination will occur individually for every enabled sink
*
* @param sink_hdl[in] Handle of destination sink
* @param pdu_meta[in] PDU along with meta information (origin, timing, status)
* @return Status
*/
isoal_status_t isoal_rx_pdu_recombine(isoal_sink_handle_t sink_hdl,
const struct isoal_pdu_rx *pdu_meta)
{
struct isoal_sink *sink = &isoal_global.sink_state[sink_hdl];
isoal_status_t err = ISOAL_STATUS_OK;
if (sink && sink->sdu_production.mode != ISOAL_PRODUCTION_MODE_DISABLED) {
if (sink->session.framed) {
err = isoal_rx_framed_consume(sink, pdu_meta);
} else {
err = isoal_rx_unframed_consume(sink, pdu_meta);
}
}
return err;
}
#endif /* CONFIG_BT_CTLR_SYNC_ISO || CONFIG_BT_CTLR_CONN_ISO */
#if defined(CONFIG_BT_CTLR_ADV_ISO) || defined(CONFIG_BT_CTLR_CONN_ISO)
/**
* @brief Find free source from statically-sized pool and allocate it
* @details Implemented as linear search since pool is very small
*
* @param hdl[out] Handle to source
* @return ISOAL_STATUS_OK if we could allocate; otherwise ISOAL_STATUS_ERR_SOURCE_ALLOC
*/
static isoal_status_t isoal_source_allocate(isoal_source_handle_t *hdl)
{
isoal_source_handle_t i;
/* Very small linear search to find first free */
for (i = 0; i < CONFIG_BT_CTLR_ISOAL_SOURCES; i++) {
if (isoal_global.source_allocated[i] == ISOAL_ALLOC_STATE_FREE) {
isoal_global.source_allocated[i] = ISOAL_ALLOC_STATE_TAKEN;
*hdl = i;
return ISOAL_STATUS_OK;
}
}
return ISOAL_STATUS_ERR_SOURCE_ALLOC; /* All entries were taken */
}
/**
* @brief Mark a source as being free to allocate again
* @param hdl[in] Handle to source
*/
static void isoal_source_deallocate(isoal_source_handle_t hdl)
{
isoal_global.source_allocated[hdl] = ISOAL_ALLOC_STATE_FREE;
}
/**
* @brief Create a new source
*
* @param handle[in] Connection handle
* @param role[in] Peripheral, Central or Broadcast
* @param framed[in] Framed case
* @param burst_number[in] Burst Number
* @param flush_timeout[in] Flush timeout
* @param max_octets[in] Maximum PDU size (Max_PDU_C_To_P / Max_PDU_P_To_C)
* @param sdu_interval[in] SDU interval
* @param iso_interval[in] ISO interval
* @param stream_sync_delay[in] CIS sync delay
* @param group_sync_delay[in] CIG sync delay
* @param pdu_alloc[in] Callback of PDU allocator
* @param pdu_write[in] Callback of PDU byte writer
* @param pdu_emit[in] Callback of PDU emitter
* @param pdu_release[in] Callback of PDU deallocator
* @param hdl[out] Handle to new source
*
* @return ISOAL_STATUS_OK if we could create a new sink; otherwise ISOAL_STATUS_ERR_SOURCE_ALLOC
*/
isoal_status_t isoal_source_create(
uint16_t handle,
uint8_t role,
uint8_t framed,
uint8_t burst_number,
uint8_t flush_timeout,
uint8_t max_octets,
uint32_t sdu_interval,
uint16_t iso_interval,
uint32_t stream_sync_delay,
uint32_t group_sync_delay,
isoal_source_pdu_alloc_cb pdu_alloc,
isoal_source_pdu_write_cb pdu_write,
isoal_source_pdu_emit_cb pdu_emit,
isoal_source_pdu_release_cb pdu_release,
isoal_source_handle_t *hdl)
{
isoal_status_t err;
/* Allocate a new source */
err = isoal_source_allocate(hdl);
if (err) {
return err;
}
struct isoal_source_session *session = &isoal_global.source_state[*hdl].session;
session->handle = handle;
session->framed = framed;
session->burst_number = burst_number;
session->iso_interval = iso_interval;
/* Todo: Next section computing various constants, should potentially be a
* function in itself as a number of the dependencies could be changed while
* a connection is active.
*/
/* Note: sdu_interval unit is uS, iso_interval is a multiple of 1.25mS */
session->pdus_per_sdu = (burst_number * sdu_interval) /
((uint32_t)iso_interval * ISO_INT_UNIT_US);
/* Set maximum PDU size */
session->max_pdu_size = max_octets;
/* Remember the platform-specific callbacks */
session->pdu_alloc = pdu_alloc;
session->pdu_write = pdu_write;
session->pdu_emit = pdu_emit;
session->pdu_release = pdu_release;
/* TODO: Constant need to be updated */
/* Initialize running seq number to zero */
session->seqn = 0;
return err;
}
/**
* @brief Get reference to configuration struct
*
* @param hdl[in] Handle to new source
* @return Reference to parameter struct, to be configured by caller
*/
struct isoal_source_config *isoal_get_source_param_ref(isoal_source_handle_t hdl)
{
LL_ASSERT(isoal_global.source_allocated[hdl] == ISOAL_ALLOC_STATE_TAKEN);
return &isoal_global.source_state[hdl].session.param;
}
/**
* @brief Atomically enable latch-in of packets and PDU production
* @param hdl[in] Handle of existing instance
*/
void isoal_source_enable(isoal_source_handle_t hdl)
{
/* Reset bookkeeping state */
memset(&isoal_global.source_state[hdl].pdu_production, 0,
sizeof(isoal_global.source_state[hdl].pdu_production));
/* Atomically enable */
isoal_global.source_state[hdl].pdu_production.mode = ISOAL_PRODUCTION_MODE_ENABLED;
}
/**
* @brief Atomically disable latch-in of packets and PDU production
* @param hdl[in] Handle of existing instance
*/
void isoal_source_disable(isoal_source_handle_t hdl)
{
/* Atomically disable */
isoal_global.source_state[hdl].pdu_production.mode = ISOAL_PRODUCTION_MODE_DISABLED;
}
struct isoal_source *isoal_source_get(isoal_source_handle_t hdl)
{
return &isoal_global.source_state[hdl];
}
/**
* @brief Disable and deallocate existing source
* @param hdl[in] Handle of existing instance
*/
void isoal_source_destroy(isoal_source_handle_t hdl)
{
/* Atomic disable */
isoal_source_disable(hdl);
/* Permit allocation anew */
isoal_source_deallocate(hdl);
}
/**
* Queue the PDU in production in the relevant LL transmit queue. If the
* attmept to release the PDU fails, the buffer linked to the PDU will be released
* and it will not be possible to retry the emit operation on the same PDU.
* @param[in] source_ctx ISO-AL source reference for this CIS / BIS
* @param[in] produced_pdu PDU in production
* @param[in] pdu_ll_id LLID to be set indicating the type of fragment
* @param[in] sdu_fragments Nummber of SDU HCI fragments consumed
* @param[in] payload_number CIS / BIS payload number
* @param[in] payload_size Length of the data written to the PDU
* @return Error status of the operation
*/
static isoal_status_t isoal_tx_pdu_emit(const struct isoal_source *source_ctx,
const struct isoal_pdu_produced *produced_pdu,
const uint8_t pdu_ll_id,
const uint8_t sdu_fragments,
const uint64_t payload_number,
const isoal_pdu_len_t payload_size)
{
struct node_tx_iso *node_tx;
isoal_status_t status;
uint16_t handle;
/* Retrieve CIS / BIS handle */
handle = bt_iso_handle(source_ctx->session.handle);
/* Retrieve Node handle */
node_tx = produced_pdu->contents.handle;
/* Set payload number */
node_tx->payload_count = payload_number & 0x7fffffffff;
node_tx->sdu_fragments = sdu_fragments;
/* Set PDU LLID */
produced_pdu->contents.pdu->ll_id = pdu_ll_id;
/* Set PDU length */
produced_pdu->contents.pdu->length = (uint8_t)payload_size;
/* Attempt to enqueue the node towards the LL */
status = source_ctx->session.pdu_emit(node_tx, handle);
if (status != ISOAL_STATUS_OK) {
/* If it fails, the node will be released and no further attempt
* will be possible
*/
BT_ERR("Failed to enqueue node (%p)", node_tx);
source_ctx->session.pdu_release(node_tx, handle, status);
}
return status;
}
/* Allocates a new PDU only if the previous PDU was emitted */
static isoal_status_t isoal_tx_allocate_pdu(struct isoal_source *source,
const struct isoal_sdu_tx *tx_sdu)
{
struct isoal_source_session *session;
struct isoal_pdu_production *pp;
struct isoal_pdu_produced *pdu;
isoal_status_t err;
err = ISOAL_STATUS_OK;
session = &source->session;
pp = &source->pdu_production;
pdu = &pp->pdu;
/* Allocate a PDU if the previous was filled (thus sent) */
const bool pdu_complete = (pp->pdu_available == 0);
if (pdu_complete) {
/* Allocate new PDU buffer */
err = session->pdu_alloc(
&pdu->contents /* [out] Updated with pointer and size */
);
if (err) {
pdu->contents.handle = NULL;
pdu->contents.pdu = NULL;
pdu->contents.size = 0;
}
/* Get maximum buffer available */
const size_t available_len = MIN(
session->max_pdu_size,
pdu->contents.size
);
/* Nothing has been written into buffer yet */
pp->pdu_written = 0;
pp->pdu_available = available_len;
LL_ASSERT(available_len > 0);
pp->pdu_cnt++;
}
return err;
}
/**
* Attempt to emit the PDU in production if it is complete.
* @param[in] source ISO-AL source reference
* @param[in] force_emit Request PDU emit
* @param[in] pdu_ll_id LLID / PDU fragment type as Start, Cont, End, Single (Unframed) or Framed
* @return Error status of operation
*/
static isoal_status_t isoal_tx_try_emit_pdu(struct isoal_source *source,
bool force_emit,
uint8_t pdu_ll_id)
{
struct isoal_pdu_production *pp;
struct isoal_pdu_produced *pdu;
isoal_status_t err;
err = ISOAL_STATUS_OK;
pp = &source->pdu_production;
pdu = &pp->pdu;
/* Emit a PDU */
const bool pdu_complete = (pp->pdu_available == 0) || force_emit;
if (force_emit) {
pp->pdu_available = 0;
}
if (pdu_complete) {
/* Emit PDU and increment the payload number */
err = isoal_tx_pdu_emit(source, pdu, pdu_ll_id,
pp->sdu_fragments,
pp->payload_number,
pp->pdu_written);
pp->payload_number++;
pp->sdu_fragments = 0;
}
return err;
}
/**
* @brief Fragment received SDU and produce unframed PDUs
* @details Destination source may have an already partially built PDU
*
* @param source[in,out] Destination source with bookkeeping state
* @param tx_sdu[in] SDU with packet boundary information
*
* @return Status
*/
static isoal_status_t isoal_tx_unframed_produce(struct isoal_source *source,
const struct isoal_sdu_tx *tx_sdu)
{
struct isoal_source_session *session;
isoal_sdu_len_t packet_available;
struct isoal_pdu_production *pp;
const uint8_t *sdu_payload;
bool zero_length_sdu;
isoal_status_t err;
bool padding_pdu;
uint8_t ll_id;
session = &source->session;
pp = &source->pdu_production;
padding_pdu = false;
err = ISOAL_STATUS_OK;
packet_available = tx_sdu->size;
sdu_payload = tx_sdu->dbuf;
LL_ASSERT(sdu_payload);
zero_length_sdu = (packet_available == 0 &&
tx_sdu->sdu_state == BT_ISO_SINGLE);
if (tx_sdu->sdu_state == BT_ISO_START ||
tx_sdu->sdu_state == BT_ISO_SINGLE) {
/* Start of a new SDU */
/* Update sequence number for received SDU
*
* BT Core V5.3 : Vol 6 Low Energy Controller : Part G IS0-AL:
* 2 ISOAL Features :
* SDUs received by the ISOAL from the upper layer shall be
* given a sequence number which is initialized to 0 when the
* CIS or BIS is created.
*
* NOTE: The upper layer may synchronize its sequence number
* with the sequence number in the ISOAL once the Datapath is
* configured and the link is established.
*/
session->seqn++;
/* Update payload counter in case time has passed since last
* SDU. This should mean that event count * burst number should
* be greater than the current payload number. In the event of
* an SDU interval smaller than the ISO interval, multiple SDUs
* will be sent in the same event. As such the current payload
* number should be retained. Payload numbers are indexed at 0
* and valid until the PDU is emitted.
*/
pp->payload_number = MAX(pp->payload_number,
(tx_sdu->target_event * session->burst_number));
/* Reset PDU fragmentation count for this SDU */
pp->pdu_cnt = 0;
/* The start of an unframed SDU will always be in a new PDU.
* There cannot be any other fragments packed.
*/
pp->sdu_fragments = 0;
}
/* PDUs should be created until the SDU fragment has been fragmented or
* if this is the last fragment of the SDU, until the required padding
* PDU(s) are sent.
*/
while ((err == ISOAL_STATUS_OK) &&
((packet_available > 0) || padding_pdu || zero_length_sdu)) {
const isoal_status_t err_alloc = isoal_tx_allocate_pdu(source, tx_sdu);
struct isoal_pdu_produced *pdu = &pp->pdu;
err |= err_alloc;
/*
* For this PDU we can only consume of packet, bounded by:
* - What can fit in the destination PDU.
* - What remains of the packet.
*/
const size_t consume_len = MIN(
packet_available,
pp->pdu_available
);
/* End of the SDU fragment has been reached when the last of the
* SDU is packed into a PDU.
*/
bool end_of_sdu_frag = !padding_pdu &&
((consume_len > 0 && consume_len == packet_available) ||
zero_length_sdu);
if (consume_len > 0) {
err |= session->pdu_write(&pdu->contents,
pp->pdu_written,
sdu_payload,
consume_len);
sdu_payload += consume_len;
pp->pdu_written += consume_len;
pp->pdu_available -= consume_len;
packet_available -= consume_len;
}
if (end_of_sdu_frag) {
/* Each PDU will carry the number of completed SDU
* fragments contained in that PDU.
*/
pp->sdu_fragments++;
}
/* End of the SDU is reached at the end of the last SDU fragment
* or if this is a single fragment SDU
*/
bool end_of_sdu = (packet_available == 0) &&
((tx_sdu->sdu_state == BT_ISO_SINGLE) ||
(tx_sdu->sdu_state == BT_ISO_END));
/* Decide PDU type
*
* BT Core V5.3 : Vol 6 Low Energy Controller : Part G IS0-AL:
* 2.1 Unframed PDU :
* LLID 0b00 PDU_BIS_LLID_COMPLETE_END:
* (1) When the payload of the ISO Data PDU contains the end
* fragment of an SDU.
* (2) When the payload of the ISO Data PDU contains a complete
* SDU.
* (3) When an SDU contains zero length data, the corresponding
* PDU shall be of zero length and the LLID field shall be
* set to 0b00.
*
* LLID 0b01 PDU_BIS_LLID_COMPLETE_END:
* (1) When the payload of the ISO Data PDU contains a start or
* a continuation fragment of an SDU.
* (2) When the ISO Data PDU is used as padding.
*/
ll_id = PDU_BIS_LLID_COMPLETE_END;
if (!end_of_sdu || padding_pdu) {
ll_id = PDU_BIS_LLID_START_CONTINUE;
}
const isoal_status_t err_emit = isoal_tx_try_emit_pdu(source, end_of_sdu, ll_id);
err |= err_emit;
/* Send padding PDU(s) if required
*
* BT Core V5.3 : Vol 6 Low Energy Controller : Part G IS0-AL:
* 2.1 Unframed PDU :
* Each SDU shall generate BN ÷ (ISO_Interval ÷ SDU_Interval)
* fragments. If an SDU generates less than this number of
* fragments, empty payloads shall be used to make up the
* number.
*/
padding_pdu = (end_of_sdu && (pp->pdu_cnt < session->pdus_per_sdu));
zero_length_sdu = false;
}
return err;
}
/**
* @brief Inserts a segmentation header at the current write point in the PDU
* under production.
* @param source source handle
* @param sc start / continuation bit value to be written
* @param cmplt complete bit value to be written
* @param time_offset value of time offset to be written
* @return status
*/
static isoal_status_t isoal_insert_seg_header_timeoffset(struct isoal_source *source,
const bool sc,
const bool cmplt,
const uint32_t time_offset)
{
struct isoal_source_session *session;
struct isoal_pdu_production *pp;
struct isoal_pdu_produced *pdu;
struct pdu_iso_sdu_sh seg_hdr;
isoal_status_t err;
uint8_t write_size;
session = &source->session;
pp = &source->pdu_production;
pdu = &pp->pdu;
write_size = PDU_ISO_SEG_HDR_SIZE + (sc ? 0 : PDU_ISO_SEG_TIMEOFFSET_SIZE);
memset(&seg_hdr, 0, sizeof(seg_hdr));
/* Check if there is enough space left in the PDU. This should not fail
* as the calling should also check before requesting insertion of a
* new header.
*/
if (pp->pdu_available < write_size) {
return ISOAL_STATUS_ERR_UNSPECIFIED;
}
seg_hdr.sc = sc;
seg_hdr.cmplt = cmplt;
seg_hdr.length = sc ? 0 : PDU_ISO_SEG_TIMEOFFSET_SIZE;
if (!sc) {
seg_hdr.timeoffset = time_offset;
}
/* Store header */
pp->seg_hdr_sc = seg_hdr.sc;
pp->seg_hdr_length = seg_hdr.length;
/* Save location of last segmentation header so that it can be updated
* as data is written.
*/
pp->last_seg_hdr_loc = pp->pdu_written;
/* Write to PDU */
err = session->pdu_write(&pdu->contents,
pp->pdu_written,
(uint8_t *) &seg_hdr,
write_size);
pp->pdu_written += write_size;
pp->pdu_available -= write_size;
return err;
}
/**
* @breif Updates the cmplt flag and length in the last segmentation header written
* @param source source handle
* @param cmplt ew value for complete flag
* param add_length length to add
* @return status
*/
static isoal_status_t isoal_update_seg_header_cmplt_length(struct isoal_source *source,
const bool cmplt,
const uint8_t add_length)
{
struct isoal_source_session *session;
struct isoal_pdu_production *pp;
struct isoal_pdu_produced *pdu;
struct pdu_iso_sdu_sh seg_hdr;
session = &source->session;
pp = &source->pdu_production;
pdu = &pp->pdu;
memset(&seg_hdr, 0, sizeof(seg_hdr));
seg_hdr.sc = pp->seg_hdr_sc;
/* Update the complete flag and length */
seg_hdr.cmplt = cmplt;
pp->seg_hdr_length += add_length;
seg_hdr.length = pp->seg_hdr_length;
/* Re-write the segmentation header at the same location */
return session->pdu_write(&pdu->contents,
pp->last_seg_hdr_loc,
(uint8_t *) &seg_hdr,
PDU_ISO_SEG_HDR_SIZE);
}
/**
* @brief Fragment received SDU and produce framed PDUs
* @details Destination source may have an already partially built PDU
*
* @param source[in,out] Destination source with bookkeeping state
* @param tx_sdu[in] SDU with packet boundary information
*
* @return Status
*/
static isoal_status_t isoal_tx_framed_produce(struct isoal_source *source,
const struct isoal_sdu_tx *tx_sdu)
{
struct isoal_source_session *session;
struct isoal_pdu_production *pp;
isoal_sdu_len_t packet_available;
const uint8_t *sdu_payload;
uint32_t time_offset;
bool zero_length_sdu;
isoal_status_t err;
bool padding_pdu;
uint8_t ll_id;
session = &source->session;
pp = &source->pdu_production;
padding_pdu = false;
err = ISOAL_STATUS_OK;
time_offset = 0;
packet_available = tx_sdu->size;
sdu_payload = tx_sdu->dbuf;
LL_ASSERT(sdu_payload);
zero_length_sdu = (packet_available == 0 &&
tx_sdu->sdu_state == BT_ISO_SINGLE);
if (tx_sdu->sdu_state == BT_ISO_START ||
tx_sdu->sdu_state == BT_ISO_SINGLE) {
/* Start of a new SDU */
/* Initialize to info provided in SDU */
uint32_t actual_cig_ref_point = tx_sdu->cig_ref_point;
uint64_t actual_event = tx_sdu->target_event;
/* Update sequence number for received SDU
*
* BT Core V5.3 : Vol 6 Low Energy Controller : Part G IS0-AL:
* 2 ISOAL Features :
* SDUs received by the ISOAL from the upper layer shall be
* given a sequence number which is initialized to 0 when the
* CIS or BIS is created.
*
* NOTE: The upper layer may synchronize its sequence number
* with the sequence number in the ISOAL once the Datapath is
* configured and the link is established.
*/
session->seqn++;
/* Reset PDU production state */
pp->pdu_state = BT_ISO_START;
/* Update payload counter in case time has passed since the last
* SDU. This should mean that event count * burst number should
* be greater than the current payload number. In the event of
* an SDU interval smaller than the ISO interval, multiple SDUs
* will be sent in the same event. As such the current payload
* number should be retained. Payload numbers are indexed at 0
* and valid until the PDU is emitted.
*/
pp->payload_number = MAX(pp->payload_number,
(tx_sdu->target_event * session->burst_number));
/* Get actual event for this payload number */
actual_event = pp->payload_number / session->burst_number;
/* Get cig reference point for this PDU based on the actual
* event being set. This might introduce some errors as the cig
* refernce point for future events could drift. However as the
* time offset calculation requires an absolute value, this
* seems to be the best candidate.
*/
if (actual_event > tx_sdu->target_event) {
actual_cig_ref_point = tx_sdu->cig_ref_point +
((actual_event - tx_sdu->target_event) * session->iso_interval *
ISO_INT_UNIT_US);
}
/* Check if time stamp on packet is later than the CIG reference
* point and adjust targets. This could happen if the SDU has
* been time-stampped at the controller when received via HCI.
*
* BT Core V5.3 : Vol 6 Low Energy Controller : Part G IS0-AL:
* 3.1 Time_Offset in framed PDUs :
* The Time_Offset shall be a positive value.
*/
if (actual_cig_ref_point <= tx_sdu->time_stamp) {
/* Advance target to next event */
actual_event++;
actual_cig_ref_point += session->iso_interval * ISO_INT_UNIT_US;
/* Set payload number */
pp->payload_number = actual_event * session->burst_number;
}
/* Calculate the time offset */
LL_ASSERT(actual_cig_ref_point > tx_sdu->time_stamp);
time_offset = actual_cig_ref_point - tx_sdu->time_stamp;
/* Reset PDU fragmentation count for this SDU */
pp->pdu_cnt = 0;
}
/* PDUs should be created until the SDU fragment has been fragmented or if
* this is the last fragment of the SDU, until the required padding PDU(s)
* are sent.
*/
while ((err == ISOAL_STATUS_OK) &&
((packet_available > 0) || padding_pdu || zero_length_sdu)) {
const isoal_status_t err_alloc = isoal_tx_allocate_pdu(source, tx_sdu);
struct isoal_pdu_produced *pdu = &pp->pdu;
err |= err_alloc;
if (pp->pdu_state == BT_ISO_START) {
/* Start of a new SDU. Segmentation header and time-offset
* should be inserted.
*/
err |= isoal_insert_seg_header_timeoffset(source,
false, false,
time_offset);
pp->pdu_state = BT_ISO_CONT;
} else if (!padding_pdu && pp->pdu_state == BT_ISO_CONT && pp->pdu_written == 0) {
/* Continuing an SDU in a new PDU. Segmentation header
* alone should be inserted.
*/
err |= isoal_insert_seg_header_timeoffset(source,
true, false,
0);
}
/*
* For this PDU we can only consume of packet, bounded by:
* - What can fit in the destination PDU.
* - What remains of the packet.
*/
const size_t consume_len = MIN(
packet_available,
pp->pdu_available
);
/* End of the SDU fragment has been reached when the last of the
* SDU is packed into a PDU.
*/
bool end_of_sdu_frag = !padding_pdu &&
((consume_len > 0 && consume_len == packet_available) ||
zero_length_sdu);
if (consume_len > 0) {
err |= session->pdu_write(&pdu->contents,
pp->pdu_written,
sdu_payload,
consume_len);
sdu_payload += consume_len;
pp->pdu_written += consume_len;
pp->pdu_available -= consume_len;
packet_available -= consume_len;
}
if (end_of_sdu_frag) {
/* Each PDU will carry the number of completed SDU
* fragments contained in that PDU.
*/
pp->sdu_fragments++;
}
/* End of the SDU is reached at the end of the last SDU fragment
* or if this is a single fragment SDU
*/
bool end_of_sdu = (packet_available == 0) &&
((tx_sdu->sdu_state == BT_ISO_SINGLE) ||
(tx_sdu->sdu_state == BT_ISO_END));
/* Update complete flag in last segmentation header */
err |= isoal_update_seg_header_cmplt_length(source, end_of_sdu, consume_len);
/* LLID is fixed for framed PDUs */
ll_id = PDU_BIS_LLID_FRAMED;
/* NOTE: Ideally even if the end of the SDU is reached, the PDU
* should not be emitted as long as there is space left. If the
* PDU is not released, it might require a flush timeout to
* trigger the release as receiving an SDU per SDU interval is
* not guaranteed. As there is no trigger for this in the
* ISO-AL, the PDU is released. This does mean that the
* bandwidth of this implementation will be less that the ideal
* supported by framed PDUs. Ideally ISOAL_SEGMENT_MIN_SIZE
* should be used to assess if there is sufficient usable space
* left in the PDU.
*/
bool release_pdu = end_of_sdu;
const isoal_status_t err_emit = isoal_tx_try_emit_pdu(source, release_pdu, ll_id);
err |= err_emit;
/* TODO: Send padding PDU(s) if required
*
* BT Core V5.3 : Vol 6 Low Energy Controller : Part G IS0-AL:
* 2 ISOAL Features :
* Padding is required when the data does not add up to the
* configured number of PDUs that are specified in the BN
* parameter per CIS or BIS event.
*
* When padding PDUs as opposed to null PDUs are required for
* framed production is not clear.
*/
padding_pdu = false;
zero_length_sdu = false;
}
return err;
}
/**
* @brief Deep copy a SDU, fragment into PDU(s)
* @details Fragmentation will occur individually for every enabled source
*
* @param source_hdl[in] Handle of destination source
* @param tx_sdu[in] SDU along with packet boudary state
* @return Status
*/
isoal_status_t isoal_tx_sdu_fragment(isoal_source_handle_t source_hdl,
struct isoal_sdu_tx *tx_sdu)
{
struct isoal_source *source;
isoal_status_t err;
source = &isoal_global.source_state[source_hdl];
err = ISOAL_STATUS_ERR_PDU_ALLOC;
if (source->pdu_production.mode != ISOAL_PRODUCTION_MODE_DISABLED) {
/* BT Core V5.3 : Vol 6 Low Energy Controller : Part G IS0-AL:
* 2 ISOAL Features :
* (1) Unframed PDUs shall only be used when the ISO_Interval
* is equal to or an integer multiple of the SDU_Interval
* and a constant time offset alignment is maintained
* between the SDU generation and the timing in the
* isochronous transport.
* (2) When the Host requests the use of framed PDUs, the
* Controller shall use framed PDUs.
*/
if (source->session.framed) {
err = isoal_tx_framed_produce(source, tx_sdu);
} else {
err = isoal_tx_unframed_produce(source, tx_sdu);
}
}
return err;
}
void isoal_tx_pdu_release(isoal_source_handle_t source_hdl,
struct node_tx_iso *node_tx)
{
struct isoal_source *source = &isoal_global.source_state[source_hdl];
if (source && source->session.pdu_release) {
source->session.pdu_release(node_tx, source->session.handle,
ISOAL_STATUS_OK);
}
}
#endif /* CONFIG_BT_CTLR_ADV_ISO || CONFIG_BT_CTLR_CONN_ISO */