From 3b196c394dd9f8f34064f5814bb287757c80ee35 Mon Sep 17 00:00:00 2001 From: Takashi Sakamoto Date: Fri, 31 Mar 2017 22:06:07 +0900 Subject: [PATCH] ALSA: firewire-lib: add no-header packet processing As long as investigating Fireface 400, IEC 61883-1/6 is not applied to its packet streaming protocol. Remarks of the specific protocol are: * Each packet doesn't include CIP headers. * 64,0 and 128,0 kHz are supported. * The device doesn't necessarily transmit 8,000 packets per second. * 0, 1, 2, 3 are used as tag for rx isochronous packets, however 0 is used for tx isochronous packets. On the other hand, there's a common feature. The number of data blocks transferred in a second is the same as sampling transmission frequency. Current ALSA IEC 61883-1/6 engine already has a method to calculate it and this driver can utilize it for rx packets, as well as tx packets. This commit adds support for the transferring protocol. CIP_NO_HEADERS flag is newly added. When this flag is set: * Both of 0 (without CIP header) and 1 (with CIP header) are used as tag to handle incoming isochronous packet. * 0 (without CIP header) is used as tag to transfer outgoing isochronous packet. * Skip CIP header evaluation. * Use unique way to calculate the quadlets of isochronous packet payload. In ALSA PCM interface, 128.0 kHz is not supported, and the ALSA IEC 61883-1/6 engine doesn't support 64.0 kHz. These modes are dropped. The sequence of rx packet has a remarkable quirk about tag. This will be described in later commits. Signed-off-by: Takashi Sakamoto Signed-off-by: Takashi Iwai --- sound/firewire/amdtp-stream.c | 80 ++++++++++++++++++++++++++++++++--- sound/firewire/amdtp-stream.h | 6 +++ 2 files changed, 81 insertions(+), 5 deletions(-) diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c index 646e8e390773..a03b37bdc274 100644 --- a/sound/firewire/amdtp-stream.c +++ b/sound/firewire/amdtp-stream.c @@ -27,6 +27,7 @@ /* isochronous header parameters */ #define ISO_DATA_LENGTH_SHIFT 16 +#define TAG_NO_CIP_HEADER 0 #define TAG_CIP 1 /* common isochronous packet header parameters */ @@ -234,11 +235,15 @@ EXPORT_SYMBOL(amdtp_stream_set_parameters); unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s) { unsigned int multiplier = 1; + unsigned int header_size = 0; if (s->flags & CIP_JUMBO_PAYLOAD) multiplier = 5; + if (!(s->flags & CIP_NO_HEADER)) + header_size = 8; - return 8 + s->syt_interval * s->data_block_quadlets * 4 * multiplier; + return header_size + + s->syt_interval * s->data_block_quadlets * 4 * multiplier; } EXPORT_SYMBOL(amdtp_stream_get_max_payload); @@ -380,7 +385,7 @@ static int queue_packet(struct amdtp_stream *s, unsigned int header_length, goto end; p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL); - p.tag = TAG_CIP; + p.tag = s->tag; p.header_length = header_length; if (payload_length > 0) p.payload_length = payload_length; @@ -457,6 +462,34 @@ static int handle_out_packet(struct amdtp_stream *s, return 0; } +static int handle_out_packet_without_header(struct amdtp_stream *s, + unsigned int payload_length, unsigned int cycle, + unsigned int index) +{ + __be32 *buffer; + unsigned int syt; + unsigned int data_blocks; + unsigned int pcm_frames; + struct snd_pcm_substream *pcm; + + buffer = s->buffer.packets[s->packet_index].buffer; + syt = calculate_syt(s, cycle); + data_blocks = calculate_data_blocks(s, syt); + pcm_frames = s->process_data_blocks(s, buffer, data_blocks, &syt); + s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff; + + payload_length = data_blocks * 4 * s->data_block_quadlets; + if (queue_out_packet(s, payload_length) < 0) + return -EIO; + + pcm = ACCESS_ONCE(s->pcm); + if (pcm && pcm_frames > 0) + update_pcm_pointers(s, pcm, pcm_frames); + + /* No need to return the number of handled data blocks. */ + return 0; +} + static int handle_in_packet(struct amdtp_stream *s, unsigned int payload_length, unsigned int cycle, unsigned int index) @@ -573,6 +606,30 @@ end: return 0; } +static int handle_in_packet_without_header(struct amdtp_stream *s, + unsigned int payload_quadlets, unsigned int cycle, + unsigned int index) +{ + __be32 *buffer; + unsigned int data_blocks; + struct snd_pcm_substream *pcm; + unsigned int pcm_frames; + + buffer = s->buffer.packets[s->packet_index].buffer; + data_blocks = payload_quadlets / s->data_block_quadlets; + pcm_frames = s->process_data_blocks(s, buffer, data_blocks, NULL); + s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff; + + if (queue_in_packet(s) < 0) + return -EIO; + + pcm = ACCESS_ONCE(s->pcm); + if (pcm && pcm_frames > 0) + update_pcm_pointers(s, pcm, pcm_frames); + + return 0; +} + /* * In CYCLE_TIMER register of IEEE 1394, 7 bits are used to represent second. On * the other hand, in DMA descriptors of 1394 OHCI, 3 bits are used to represent @@ -616,7 +673,7 @@ static void out_stream_callback(struct fw_iso_context *context, u32 tstamp, for (i = 0; i < packets; ++i) { cycle = increment_cycle_count(cycle, 1); - if (handle_out_packet(s, 0, cycle, i) < 0) { + if (s->handle_packet(s, 0, cycle, i) < 0) { s->packet_index = -1; amdtp_stream_pcm_abort(s); return; @@ -663,7 +720,7 @@ static void in_stream_callback(struct fw_iso_context *context, u32 tstamp, break; } - if (handle_in_packet(s, payload_length, cycle, i) < 0) + if (s->handle_packet(s, payload_length, cycle, i) < 0) break; } @@ -699,10 +756,18 @@ static void amdtp_stream_first_callback(struct fw_iso_context *context, packets = header_length / IN_PACKET_HEADER_SIZE; cycle = decrement_cycle_count(cycle, packets); context->callback.sc = in_stream_callback; + if (s->flags & CIP_NO_HEADER) + s->handle_packet = handle_in_packet_without_header; + else + s->handle_packet = handle_in_packet; } else { packets = header_length / 4; cycle = increment_cycle_count(cycle, QUEUE_LENGTH - packets); context->callback.sc = out_stream_callback; + if (s->flags & CIP_NO_HEADER) + s->handle_packet = handle_out_packet_without_header; + else + s->handle_packet = handle_out_packet; } s->start_cycle = cycle; @@ -782,6 +847,11 @@ int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed) amdtp_stream_update(s); + if (s->flags & CIP_NO_HEADER) + s->tag = TAG_NO_CIP_HEADER; + else + s->tag = TAG_CIP; + s->packet_index = 0; do { if (s->direction == AMDTP_IN_STREAM) @@ -794,7 +864,7 @@ int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed) /* NOTE: TAG1 matches CIP. This just affects in stream. */ tag = FW_ISO_CONTEXT_MATCH_TAG1; - if (s->flags & CIP_EMPTY_WITH_TAG0) + if ((s->flags & CIP_EMPTY_WITH_TAG0) || (s->flags & CIP_NO_HEADER)) tag |= FW_ISO_CONTEXT_MATCH_TAG0; s->callbacked = false; diff --git a/sound/firewire/amdtp-stream.h b/sound/firewire/amdtp-stream.h index a31dfd849821..2bd4de4c7bb7 100644 --- a/sound/firewire/amdtp-stream.h +++ b/sound/firewire/amdtp-stream.h @@ -31,6 +31,7 @@ * allows 5 times as large as IEC 61883-6 defines. * @CIP_HEADER_WITHOUT_EOH: Only for in-stream. CIP Header doesn't include * valid EOH. + * @CIP_NO_HEADERS: a lack of headers in packets */ enum cip_flags { CIP_NONBLOCKING = 0x00, @@ -42,6 +43,7 @@ enum cip_flags { CIP_EMPTY_HAS_WRONG_DBC = 0x20, CIP_JUMBO_PAYLOAD = 0x40, CIP_HEADER_WITHOUT_EOH = 0x80, + CIP_NO_HEADER = 0x100, }; /** @@ -104,6 +106,10 @@ struct amdtp_stream { struct fw_iso_context *context; struct iso_packets_buffer buffer; int packet_index; + int tag; + int (*handle_packet)(struct amdtp_stream *s, + unsigned int payload_quadlets, unsigned int cycle, + unsigned int index); /* For CIP headers. */ unsigned int source_node_id_field; -- 2.20.1