sound/firewire/motu/motu-command-dsp-message-parser.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 //
   3 // motu-command-dsp-message-parser.c - a part of driver for MOTU FireWire series
   4 //
   5 // Copyright (c) 2021 Takashi Sakamoto <o-takashi@sakamocchi.jp>
   6
   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)
  12 //  * Traveler mk3
  13 //  * Track 16
  14 //
  15 // Isochronous packets from the above models includes messages to report state of hardware meter.
  16
  17 #include "motu.h"
  18
  19 enum msg_parser_state {
  20         INITIALIZED,
  21         FRAGMENT_DETECTED,
  22         AVAILABLE,
  23 };
  24
  25 struct msg_parser {
  26         spinlock_t lock;
  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;
  32         u64 value;
  33         struct snd_firewire_motu_command_dsp_meter meter;
  34 };
  35
  36 int snd_motu_command_dsp_message_parser_new(struct snd_motu *motu)
  37 {
  38         struct msg_parser *parser;
  39
  40         parser = devm_kzalloc(&motu->card->card_dev, sizeof(*parser), GFP_KERNEL);
  41         if (!parser)
  42                 return -ENOMEM;
  43         spin_lock_init(&parser->lock);
  44         motu->message_parser = parser;
  45
  46         return 0;
  47 }
  48
  49 int snd_motu_command_dsp_message_parser_init(struct snd_motu *motu, enum cip_sfc sfc)
  50 {
  51         struct msg_parser *parser = motu->message_parser;
  52
  53         parser->state = INITIALIZED;
  54
  55         // All of data blocks don't have messages with meaningful information.
  56         switch (sfc) {
  57         case CIP_SFC_176400:
  58         case CIP_SFC_192000:
  59                 parser->interval = 4;
  60                 break;
  61         case CIP_SFC_88200:
  62         case CIP_SFC_96000:
  63                 parser->interval = 2;
  64                 break;
  65         case CIP_SFC_32000:
  66         case CIP_SFC_44100:
  67         case CIP_SFC_48000:
  68         default:
  69                 parser->interval = 1;
  70                 break;
  71         }
  72
  73         return 0;
  74 }
  75
  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
  82
  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)
  85 {
  86         struct msg_parser *parser = motu->message_parser;
  87         unsigned int interval = parser->interval;
  88         unsigned long flags;
  89         int i;
  90
  91         spin_lock_irqsave(&parser->lock, flags);
  92
  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;
  97                 int j;
  98
  99                 for (j = 0; j < data_blocks; ++j) {
 100                         u8 *b = (u8 *)buffer;
 101                         buffer += data_block_quadlets;
 102
 103                         switch (parser->state) {
 104                         case INITIALIZED:
 105                         {
 106                                 u8 fragment = b[FRAGMENT_POS];
 107
 108                                 if (fragment > 0) {
 109                                         parser->value = fragment;
 110                                         parser->message_count = 1;
 111                                         parser->state = FRAGMENT_DETECTED;
 112                                 }
 113                                 break;
 114                         }
 115                         case FRAGMENT_DETECTED:
 116                         {
 117                                 if (parser->message_count % interval == 0) {
 118                                         u8 fragment = b[FRAGMENT_POS];
 119
 120                                         parser->value >>= 8;
 121                                         parser->value |= (u64)fragment << 56;
 122
 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;
 128                                         }
 129                                 }
 130                                 ++parser->message_count;
 131                                 break;
 132                         }
 133                         case AVAILABLE:
 134                         default:
 135                         {
 136                                 if (parser->message_count % interval == 0) {
 137                                         u8 fragment = b[FRAGMENT_POS];
 138
 139                                         parser->value >>= 8;
 140                                         parser->value |= (u64)fragment << 56;
 141                                         ++parser->fragment_pos;
 142
 143                                         if (parser->fragment_pos == 4) {
 144                                                 // Skip the last two quadlets since they could be
 145                                                 // invalid value (0xffffffff) as floating point
 146                                                 // number.
 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;
 151                                                 }
 152                                                 ++parser->value_index;
 153                                                 parser->fragment_pos = 0;
 154                                         }
 155
 156                                         if (parser->value == VALUES_AT_IMAGE_END) {
 157                                                 parser->value_index = 0;
 158                                                 parser->fragment_pos = 0;
 159                                                 parser->message_count = 0;
 160                                         }
 161                                 }
 162                                 ++parser->message_count;
 163                                 break;
 164                         }
 165                         }
 166                 }
 167         }
 168
 169         spin_unlock_irqrestore(&parser->lock, flags);
 170 }
 171
 172 void snd_motu_command_dsp_message_parser_copy_meter(struct snd_motu *motu,
 173                                         struct snd_firewire_motu_command_dsp_meter *meter)
 174 {
 175         struct msg_parser *parser = motu->message_parser;
 176         unsigned long flags;
 177
 178         spin_lock_irqsave(&parser->lock, flags);
 179         memcpy(meter, &parser->meter, sizeof(*meter));
 180         spin_unlock_irqrestore(&parser->lock, flags);
 181 }