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>

diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index 371cf978fbed369b72a0018c5a034d67b23a88d2..65c5ed7488a36cf1ebf6f0a9a6ee01eb031da238 100644 (file)
--- 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]);

diff --git a/sound/firewire/amdtp-stream.h b/sound/firewire/amdtp-stream.h
index edf5646b37089c6e4cdff15b5321886e1e6f3a35..679053d9c28f673f4d58549418d7ed118313b578 100644 (file)
--- a/sound/firewire/amdtp-stream.h
+++ b/sound/firewire/amdtp-stream.h
@@ -106,6 +106,7 @@ struct amdtp_stream {
        unsigned int source_node_id_field;
        unsigned int data_block_quadlets;
        unsigned int data_block_counter;
+       unsigned int sph;
        unsigned int fmt;
        unsigned int fdf;
        /* quirk: fixed interval of dbc between previos/current packets. */