1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ff-transaction.c - a part of driver for RME Fireface series 4 * 5 * Copyright (c) 2015-2017 Takashi Sakamoto 6 */ 7 8 #include "ff.h" 9 10 static void finish_transmit_midi_msg(struct snd_ff *ff, unsigned int port, 11 int rcode) 12 { 13 struct snd_rawmidi_substream *substream = 14 READ_ONCE(ff->rx_midi_substreams[port]); 15 16 if (rcode_is_permanent_error(rcode)) { 17 ff->rx_midi_error[port] = true; 18 return; 19 } 20 21 if (rcode != RCODE_COMPLETE) { 22 /* Transfer the message again, immediately. */ 23 ff->next_ktime[port] = 0; 24 schedule_work(&ff->rx_midi_work[port]); 25 return; 26 } 27 28 snd_rawmidi_transmit_ack(substream, ff->rx_bytes[port]); 29 ff->rx_bytes[port] = 0; 30 31 if (!snd_rawmidi_transmit_empty(substream)) 32 schedule_work(&ff->rx_midi_work[port]); 33 } 34 35 static void finish_transmit_midi0_msg(struct fw_card *card, int rcode, 36 void *data, size_t length, 37 void *callback_data) 38 { 39 struct snd_ff *ff = 40 container_of(callback_data, struct snd_ff, transactions[0]); 41 finish_transmit_midi_msg(ff, 0, rcode); 42 } 43 44 static void finish_transmit_midi1_msg(struct fw_card *card, int rcode, 45 void *data, size_t length, 46 void *callback_data) 47 { 48 struct snd_ff *ff = 49 container_of(callback_data, struct snd_ff, transactions[1]); 50 finish_transmit_midi_msg(ff, 1, rcode); 51 } 52 53 static void transmit_midi_msg(struct snd_ff *ff, unsigned int port) 54 { 55 struct snd_rawmidi_substream *substream = 56 READ_ONCE(ff->rx_midi_substreams[port]); 57 int quad_count; 58 59 struct fw_device *fw_dev = fw_parent_device(ff->unit); 60 unsigned long long addr; 61 int generation; 62 fw_transaction_callback_t callback; 63 int tcode; 64 65 if (substream == NULL || snd_rawmidi_transmit_empty(substream)) 66 return; 67 68 if (ff->rx_bytes[port] > 0 || ff->rx_midi_error[port]) 69 return; 70 71 /* Do it in next chance. */ 72 if (ktime_after(ff->next_ktime[port], ktime_get())) { 73 schedule_work(&ff->rx_midi_work[port]); 74 return; 75 } 76 77 quad_count = ff->spec->protocol->fill_midi_msg(ff, substream, port); 78 if (quad_count <= 0) 79 return; 80 81 if (port == 0) { 82 addr = ff->spec->midi_rx_addrs[0]; 83 callback = finish_transmit_midi0_msg; 84 } else { 85 addr = ff->spec->midi_rx_addrs[1]; 86 callback = finish_transmit_midi1_msg; 87 } 88 89 /* Set interval to next transaction. */ 90 ff->next_ktime[port] = ktime_add_ns(ktime_get(), 91 ff->rx_bytes[port] * 8 * (NSEC_PER_SEC / 31250)); 92 93 if (quad_count == 1) 94 tcode = TCODE_WRITE_QUADLET_REQUEST; 95 else 96 tcode = TCODE_WRITE_BLOCK_REQUEST; 97 98 /* 99 * In Linux FireWire core, when generation is updated with memory 100 * barrier, node id has already been updated. In this module, After 101 * this smp_rmb(), load/store instructions to memory are completed. 102 * Thus, both of generation and node id are available with recent 103 * values. This is a light-serialization solution to handle bus reset 104 * events on IEEE 1394 bus. 105 */ 106 generation = fw_dev->generation; 107 smp_rmb(); 108 fw_send_request(fw_dev->card, &ff->transactions[port], tcode, 109 fw_dev->node_id, generation, fw_dev->max_speed, 110 addr, &ff->msg_buf[port], quad_count * 4, 111 callback, &ff->transactions[port]); 112 } 113 114 static void transmit_midi0_msg(struct work_struct *work) 115 { 116 struct snd_ff *ff = container_of(work, struct snd_ff, rx_midi_work[0]); 117 118 transmit_midi_msg(ff, 0); 119 } 120 121 static void transmit_midi1_msg(struct work_struct *work) 122 { 123 struct snd_ff *ff = container_of(work, struct snd_ff, rx_midi_work[1]); 124 125 transmit_midi_msg(ff, 1); 126 } 127 128 static void handle_midi_msg(struct fw_card *card, struct fw_request *request, 129 int tcode, int destination, int source, 130 int generation, unsigned long long offset, 131 void *data, size_t length, void *callback_data) 132 { 133 struct snd_ff *ff = callback_data; 134 __le32 *buf = data; 135 136 fw_send_response(card, request, RCODE_COMPLETE); 137 138 offset -= ff->async_handler.offset; 139 ff->spec->protocol->handle_midi_msg(ff, (unsigned int)offset, buf, 140 length); 141 } 142 143 static int allocate_own_address(struct snd_ff *ff, int i) 144 { 145 struct fw_address_region midi_msg_region; 146 int err; 147 148 ff->async_handler.length = ff->spec->midi_addr_range; 149 ff->async_handler.address_callback = handle_midi_msg; 150 ff->async_handler.callback_data = ff; 151 152 midi_msg_region.start = 0x000100000000ull * i; 153 midi_msg_region.end = midi_msg_region.start + ff->async_handler.length; 154 155 err = fw_core_add_address_handler(&ff->async_handler, &midi_msg_region); 156 if (err >= 0) { 157 /* Controllers are allowed to register this region. */ 158 if (ff->async_handler.offset & 0x0000ffffffff) { 159 fw_core_remove_address_handler(&ff->async_handler); 160 err = -EAGAIN; 161 } 162 } 163 164 return err; 165 } 166 167 // Controllers are allowed to register higher 4 bytes of destination address to 168 // receive asynchronous transactions for MIDI messages, while the way to 169 // register lower 4 bytes of address is different depending on protocols. For 170 // details, please refer to comments in protocol implementations. 171 // 172 // This driver expects userspace applications to configure registers for the 173 // lower address because in most cases such registers has the other settings. 174 int snd_ff_transaction_reregister(struct snd_ff *ff) 175 { 176 struct fw_card *fw_card = fw_parent_device(ff->unit)->card; 177 u32 addr; 178 __le32 reg; 179 180 /* 181 * Controllers are allowed to register its node ID and upper 2 byte of 182 * local address to listen asynchronous transactions. 183 */ 184 addr = (fw_card->node_id << 16) | (ff->async_handler.offset >> 32); 185 reg = cpu_to_le32(addr); 186 return snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST, 187 ff->spec->midi_high_addr, 188 ®, sizeof(reg), 0); 189 } 190 191 int snd_ff_transaction_register(struct snd_ff *ff) 192 { 193 int i, err; 194 195 /* 196 * Allocate in Memory Space of IEC 13213, but lower 4 byte in LSB should 197 * be zero due to device specification. 198 */ 199 for (i = 0; i < 0xffff; i++) { 200 err = allocate_own_address(ff, i); 201 if (err != -EBUSY && err != -EAGAIN) 202 break; 203 } 204 if (err < 0) 205 return err; 206 207 err = snd_ff_transaction_reregister(ff); 208 if (err < 0) 209 return err; 210 211 INIT_WORK(&ff->rx_midi_work[0], transmit_midi0_msg); 212 INIT_WORK(&ff->rx_midi_work[1], transmit_midi1_msg); 213 214 return 0; 215 } 216 217 void snd_ff_transaction_unregister(struct snd_ff *ff) 218 { 219 __le32 reg; 220 221 if (ff->async_handler.callback_data == NULL) 222 return; 223 ff->async_handler.callback_data = NULL; 224 225 /* Release higher 4 bytes of address. */ 226 reg = cpu_to_le32(0x00000000); 227 snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST, 228 ff->spec->midi_high_addr, 229 ®, sizeof(reg), 0); 230 231 fw_core_remove_address_handler(&ff->async_handler); 232 } 233