Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | |
| 2 | Serial UART 16450/16550 MIDI driver |
| 3 | =================================== |
| 4 | |
| 5 | The adaptor module parameter allows you to select either: |
| 6 | |
| 7 | 0 - Roland Soundcanvas support (default) |
| 8 | 1 - Midiator MS-124T support (1) |
| 9 | 2 - Midiator MS-124W S/A mode (2) |
| 10 | 3 - MS-124W M/B mode support (3) |
| 11 | 4 - Generic device with multiple input support (4) |
| 12 | |
| 13 | For the Midiator MS-124W, you must set the physical M-S and A-B |
| 14 | switches on the Midiator to match the driver mode you select. |
| 15 | |
| 16 | In Roland Soundcanvas mode, multiple ALSA raw MIDI substreams are supported |
| 17 | (midiCnD0-midiCnD15). Whenever you write to a different substream, the driver |
| 18 | sends the nonstandard MIDI command sequence F5 NN, where NN is the substream |
| 19 | number plus 1. Roland modules use this command to switch between different |
| 20 | "parts", so this feature lets you treat each part as a distinct raw MIDI |
| 21 | substream. The driver provides no way to send F5 00 (no selection) or to not |
| 22 | send the F5 NN command sequence at all; perhaps it ought to. |
| 23 | |
| 24 | Usage example for simple serial converter: |
| 25 | |
| 26 | /sbin/setserial /dev/ttyS0 uart none |
| 27 | /sbin/modprobe snd-serial-u16550 port=0x3f8 irq=4 speed=115200 |
| 28 | |
| 29 | Usage example for Roland SoundCanvas with 4 MIDI ports: |
| 30 | |
| 31 | /sbin/setserial /dev/ttyS0 uart none |
| 32 | /sbin/modprobe snd-serial-u16550 port=0x3f8 irq=4 outs=4 |
| 33 | |
| 34 | In MS-124T mode, one raw MIDI substream is supported (midiCnD0); the outs |
| 35 | module parameter is automatically set to 1. The driver sends the same data to |
| 36 | all four MIDI Out connectors. Set the A-B switch and the speed module |
| 37 | parameter to match (A=19200, B=9600). |
| 38 | |
| 39 | Usage example for MS-124T, with A-B switch in A position: |
| 40 | |
| 41 | /sbin/setserial /dev/ttyS0 uart none |
| 42 | /sbin/modprobe snd-serial-u16550 port=0x3f8 irq=4 adaptor=1 \ |
| 43 | speed=19200 |
| 44 | |
| 45 | In MS-124W S/A mode, one raw MIDI substream is supported (midiCnD0); |
| 46 | the outs module parameter is automatically set to 1. The driver sends |
| 47 | the same data to all four MIDI Out connectors at full MIDI speed. |
| 48 | |
| 49 | Usage example for S/A mode: |
| 50 | |
| 51 | /sbin/setserial /dev/ttyS0 uart none |
| 52 | /sbin/modprobe snd-serial-u16550 port=0x3f8 irq=4 adaptor=2 |
| 53 | |
| 54 | In MS-124W M/B mode, the driver supports 16 ALSA raw MIDI substreams; |
| 55 | the outs module parameter is automatically set to 16. The substream |
| 56 | number gives a bitmask of which MIDI Out connectors the data should be |
| 57 | sent to, with midiCnD1 sending to Out 1, midiCnD2 to Out 2, midiCnD4 to |
| 58 | Out 3, and midiCnD8 to Out 4. Thus midiCnD15 sends the data to all 4 ports. |
| 59 | As a special case, midiCnD0 also sends to all ports, since it is not useful |
| 60 | to send the data to no ports. M/B mode has extra overhead to select the MIDI |
| 61 | Out for each byte, so the aggregate data rate across all four MIDI Outs is |
| 62 | at most one byte every 520 us, as compared with the full MIDI data rate of |
| 63 | one byte every 320 us per port. |
| 64 | |
| 65 | Usage example for M/B mode: |
| 66 | |
| 67 | /sbin/setserial /dev/ttyS0 uart none |
| 68 | /sbin/modprobe snd-serial-u16550 port=0x3f8 irq=4 adaptor=3 |
| 69 | |
| 70 | The MS-124W hardware's M/A mode is currently not supported. This mode allows |
| 71 | the MIDI Outs to act independently at double the aggregate throughput of M/B, |
| 72 | but does not allow sending the same byte simultaneously to multiple MIDI Outs. |
| 73 | The M/A protocol requires the driver to twiddle the modem control lines under |
| 74 | timing constraints, so it would be a bit more complicated to implement than |
| 75 | the other modes. |
| 76 | |
| 77 | Midiator models other than MS-124W and MS-124T are currently not supported. |
| 78 | Note that the suffix letter is significant; the MS-124 and MS-124B are not |
| 79 | compatible, nor are the other known models MS-101, MS-101B, MS-103, and MS-114. |
| 80 | I do have documentation (tim.mann@compaq.com) that partially covers these models, |
| 81 | but no units to experiment with. The MS-124W support is tested with a real unit. |
| 82 | The MS-124T support is untested, but should work. |
| 83 | |
| 84 | The Generic driver supports multiple input and output substreams over a single |
| 85 | serial port. Similar to Roland Soundcanvas mode, F5 NN is used to select the |
| 86 | appropriate input or output stream (depending on the data direction). |
| 87 | Additionally, the CTS signal is used to regulate the data flow. The number of |
| 88 | inputs is specified by the ins parameter. |