diff options
| author | Takashi Sakamoto <o-takashi@sakamocchi.jp> | 2017-03-22 15:30:16 +0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2017-03-28 13:33:26 +0300 |
| commit | 9863874f02e1cca65bdb112336250890b2ded64a (patch) | |
| tree | d14a93124402ac63f01a8926a3623bb801a6348f /sound/firewire/amdtp-stream.c | |
| parent | a04513f8b1980e7ddd9082461aceaf8b3e8f4981 (diff) | |
| download | linux-9863874f02e1cca65bdb112336250890b2ded64a.tar.xz | |
ALSA: firewire-lib: add support for source packet header field in CIP header
In IEC 61883-1, CIP headers can have a SPH field. When a packet has 1 in
SPH field of its CIP header, the packet has a source packet headers. A
source packet header consists of 32 bit field (= 1 quadlet) and it
transfers time stamp, which is the same value as the lower 25 bits of the
IEEE 1394 CYCLE_TIMER register and the rest is zero.
This commit just supports source packet header field because IEC 61883-1
includes ambiguity the position of this header and its count. Each
protocol layer is allowed to have actual implementation according its
requirements.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/firewire/amdtp-stream.c')
| -rw-r--r-- | sound/firewire/amdtp-stream.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c index 371cf978fbed..65c5ed7488a3 100644 --- a/sound/firewire/amdtp-stream.c +++ b/sound/firewire/amdtp-stream.c @@ -37,6 +37,8 @@ #define CIP_SID_MASK 0x3f000000 #define CIP_DBS_MASK 0x00ff0000 #define CIP_DBS_SHIFT 16 +#define CIP_SPH_MASK 0x00000400 +#define CIP_SPH_SHIFT 10 #define CIP_DBC_MASK 0x000000ff #define CIP_FMT_SHIFT 24 #define CIP_FMT_MASK 0x3f000000 @@ -426,6 +428,7 @@ static int handle_out_packet(struct amdtp_stream *s, unsigned int cycle, buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) | (s->data_block_quadlets << CIP_DBS_SHIFT) | + ((s->sph << CIP_SPH_SHIFT) & CIP_SPH_MASK) | s->data_block_counter); buffer[1] = cpu_to_be32(CIP_EOH | ((s->fmt << CIP_FMT_SHIFT) & CIP_FMT_MASK) | @@ -454,7 +457,7 @@ static int handle_in_packet(struct amdtp_stream *s, { __be32 *buffer; u32 cip_header[2]; - unsigned int fmt, fdf, syt; + unsigned int sph, fmt, fdf, syt; unsigned int data_block_quadlets, data_block_counter, dbc_interval; unsigned int data_blocks; struct snd_pcm_substream *pcm; @@ -482,8 +485,9 @@ static int handle_in_packet(struct amdtp_stream *s, } /* Check valid protocol or not. */ + sph = (cip_header[0] & CIP_SPH_MASK) >> CIP_SPH_SHIFT; fmt = (cip_header[1] & CIP_FMT_MASK) >> CIP_FMT_SHIFT; - if (fmt != s->fmt) { + if (sph != s->sph || fmt != s->fmt) { dev_info_ratelimited(&s->unit->device, "Detect unexpected protocol: %08x %08x\n", cip_header[0], cip_header[1]); |