1 // SPDX-License-Identifier: GPL-2.0-only
3 // motu-command-dsp-message-parser.c - a part of driver for MOTU FireWire series
5 // Copyright (c) 2021 Takashi Sakamoto <o-takashi@sakamocchi.jp>
7 // Below models allow software to configure their DSP function by command transferred in
8 // asynchronous transaction:
9 // * 828 mk3 (FireWire only and Hybrid)
10 // * 896 mk3 (FireWire only and Hybrid)
11 // * Ultralite mk3 (FireWire only and Hybrid)
15 // Isochronous packets from the above models includes messages to report state of hardware meter.
19 enum msg_parser_state {
27 enum msg_parser_state state;
28 unsigned int interval;
29 unsigned int message_count;
30 unsigned int fragment_pos;
31 unsigned int value_index;
33 struct snd_firewire_motu_command_dsp_meter meter;
36 int snd_motu_command_dsp_message_parser_new(struct snd_motu *motu)
38 struct msg_parser *parser;
40 parser = devm_kzalloc(&motu->card->card_dev, sizeof(*parser), GFP_KERNEL);
43 spin_lock_init(&parser->lock);
44 motu->message_parser = parser;
49 int snd_motu_command_dsp_message_parser_init(struct snd_motu *motu, enum cip_sfc sfc)
51 struct msg_parser *parser = motu->message_parser;
53 parser->state = INITIALIZED;
55 // All of data blocks don't have messages with meaningful information.
76 #define FRAGMENT_POS 6
77 #define MIDI_BYTE_POS 7
78 #define MIDI_FLAG_POS 8
79 // One value of hardware meter consists of 4 messages.
80 #define FRAGMENTS_PER_VALUE 4
81 #define VALUES_AT_IMAGE_END 0xffffffffffffffff
83 void snd_motu_command_dsp_message_parser_parse(struct snd_motu *motu, const struct pkt_desc *descs,
84 unsigned int desc_count, unsigned int data_block_quadlets)
86 struct msg_parser *parser = motu->message_parser;
87 unsigned int interval = parser->interval;
91 spin_lock_irqsave(&parser->lock, flags);
93 for (i = 0; i < desc_count; ++i) {
94 const struct pkt_desc *desc = descs + i;
95 __be32 *buffer = desc->ctx_payload;
96 unsigned int data_blocks = desc->data_blocks;
99 for (j = 0; j < data_blocks; ++j) {
100 u8 *b = (u8 *)buffer;
101 buffer += data_block_quadlets;
103 switch (parser->state) {
106 u8 fragment = b[FRAGMENT_POS];
109 parser->value = fragment;
110 parser->message_count = 1;
111 parser->state = FRAGMENT_DETECTED;
115 case FRAGMENT_DETECTED:
117 if (parser->message_count % interval == 0) {
118 u8 fragment = b[FRAGMENT_POS];
121 parser->value |= (u64)fragment << 56;
123 if (parser->value == VALUES_AT_IMAGE_END) {
124 parser->state = AVAILABLE;
125 parser->fragment_pos = 0;
126 parser->value_index = 0;
127 parser->message_count = 0;
130 ++parser->message_count;
136 if (parser->message_count % interval == 0) {
137 u8 fragment = b[FRAGMENT_POS];
140 parser->value |= (u64)fragment << 56;
141 ++parser->fragment_pos;
143 if (parser->fragment_pos == 4) {
144 // Skip the last two quadlets since they could be
145 // invalid value (0xffffffff) as floating point
147 if (parser->value_index <
148 SNDRV_FIREWIRE_MOTU_COMMAND_DSP_METER_COUNT - 2) {
149 u32 val = (u32)(parser->value >> 32);
150 parser->meter.data[parser->value_index] = val;
152 ++parser->value_index;
153 parser->fragment_pos = 0;
156 if (parser->value == VALUES_AT_IMAGE_END) {
157 parser->value_index = 0;
158 parser->fragment_pos = 0;
159 parser->message_count = 0;
162 ++parser->message_count;
169 spin_unlock_irqrestore(&parser->lock, flags);
172 void snd_motu_command_dsp_message_parser_copy_meter(struct snd_motu *motu,
173 struct snd_firewire_motu_command_dsp_meter *meter)
175 struct msg_parser *parser = motu->message_parser;
178 spin_lock_irqsave(&parser->lock, flags);
179 memcpy(meter, &parser->meter, sizeof(*meter));
180 spin_unlock_irqrestore(&parser->lock, flags);