From 13b8b78c7fd65abf8b100cc05166cca1d10a1e80 Mon Sep 17 00:00:00 2001 From: Takashi Sakamoto Date: Tue, 22 Dec 2015 09:15:41 +0900 Subject: [PATCH] ALSA: oxfw: copy handlers of asynchronous transaction for MIDI capture This commit copies some functions of asynchronous transactions for MIDI capture, to merge scs1x module. The features of payload in asynchronous transaction are: * System exclusive messages for SCS.1 are encoded without ID data. In this encoding scheme, 4 bits in LSB are available. The bits are squashed in payload byte. Thus, one payload byte transfers two MIDI messages. * The first byte of payload byte means: * 0x00: depending on second payload byte * 0xf9: including escaped system exclusive messages for SCS.1, up to 3 byte (= 6 MIDI messages) * the others: including MIDI 1.0 messages * the others: including escaped system exclusive messages for SCS.1, up to 64 bytes Signed-off-by: Takashi Sakamoto Signed-off-by: Takashi Iwai --- sound/firewire/oxfw/oxfw-scs1x.c | 83 +++++++++++++++++++++++++++++++- 1 file changed, 82 insertions(+), 1 deletion(-) diff --git a/sound/firewire/oxfw/oxfw-scs1x.c b/sound/firewire/oxfw/oxfw-scs1x.c index 32a7b673cbc8..3e0349bced96 100644 --- a/sound/firewire/oxfw/oxfw-scs1x.c +++ b/sound/firewire/oxfw/oxfw-scs1x.c @@ -11,18 +11,99 @@ #define HSS1394_ADDRESS 0xc007dedadadaULL #define HSS1394_MAX_PACKET_SIZE 64 +#define HSS1394_TAG_USER_DATA 0x00 #define HSS1394_TAG_CHANGE_ADDRESS 0xf1 struct fw_scs1x { struct fw_address_handler hss_handler; + u8 input_escape_count; + struct snd_rawmidi_substream *input; }; +static const u8 sysex_escape_prefix[] = { + 0xf0, /* SysEx begin */ + 0x00, 0x01, 0x60, /* Stanton DJ */ + 0x48, 0x53, 0x53, /* "HSS" */ +}; + +static void midi_input_escaped_byte(struct snd_rawmidi_substream *stream, + u8 byte) +{ + u8 nibbles[2]; + + nibbles[0] = byte >> 4; + nibbles[1] = byte & 0x0f; + snd_rawmidi_receive(stream, nibbles, 2); +} + +static void midi_input_byte(struct fw_scs1x *scs, + struct snd_rawmidi_substream *stream, u8 byte) +{ + const u8 eox = 0xf7; + + if (scs->input_escape_count > 0) { + midi_input_escaped_byte(stream, byte); + scs->input_escape_count--; + if (scs->input_escape_count == 0) + snd_rawmidi_receive(stream, &eox, sizeof(eox)); + } else if (byte == 0xf9) { + snd_rawmidi_receive(stream, sysex_escape_prefix, + ARRAY_SIZE(sysex_escape_prefix)); + midi_input_escaped_byte(stream, 0x00); + midi_input_escaped_byte(stream, 0xf9); + scs->input_escape_count = 3; + } else { + snd_rawmidi_receive(stream, &byte, 1); + } +} + +static void midi_input_packet(struct fw_scs1x *scs, + struct snd_rawmidi_substream *stream, + const u8 *data, unsigned int bytes) +{ + unsigned int i; + const u8 eox = 0xf7; + + if (data[0] == HSS1394_TAG_USER_DATA) { + for (i = 1; i < bytes; ++i) + midi_input_byte(scs, stream, data[i]); + } else { + snd_rawmidi_receive(stream, sysex_escape_prefix, + ARRAY_SIZE(sysex_escape_prefix)); + for (i = 0; i < bytes; ++i) + midi_input_escaped_byte(stream, data[i]); + snd_rawmidi_receive(stream, &eox, sizeof(eox)); + } +} + static void handle_hss(struct fw_card *card, struct fw_request *request, int tcode, int destination, int source, int generation, unsigned long long offset, void *data, size_t length, void *callback_data) { - fw_send_response(card, request, RCODE_COMPLETE); + struct fw_scs1x *scs = callback_data; + struct snd_rawmidi_substream *stream; + int rcode; + + if (offset != scs->hss_handler.offset) { + rcode = RCODE_ADDRESS_ERROR; + goto end; + } + if (tcode != TCODE_WRITE_QUADLET_REQUEST && + tcode != TCODE_WRITE_BLOCK_REQUEST) { + rcode = RCODE_TYPE_ERROR; + goto end; + } + + if (length >= 1) { + stream = ACCESS_ONCE(scs->input); + if (stream) + midi_input_packet(scs, stream, data, length); + } + + rcode = RCODE_COMPLETE; +end: + fw_send_response(card, request, rcode); } static int register_address(struct snd_oxfw *oxfw) -- 2.20.1