sound/isa/msnd/msnd_midi.c

   1 /*
   2  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   3  *  Copyright (c) 2009 by Krzysztof Helt
   4  *  Routines for control of MPU-401 in UART mode
   5  *
   6  *  MPU-401 supports UART mode which is not capable generate transmit
   7  *  interrupts thus output is done via polling. Also, if irq < 0, then
   8  *  input is done also via polling. Do not expect good performance.
   9  *
  10  *
  11  *   This program is free software; you can redistribute it and/or modify
  12  *   it under the terms of the GNU General Public License as published by
  13  *   the Free Software Foundation; either version 2 of the License, or
  14  *   (at your option) any later version.
  15  *
  16  *   This program is distributed in the hope that it will be useful,
  17  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *   GNU General Public License for more details.
  20  *
  21  *   You should have received a copy of the GNU General Public License
  22  *   along with this program; if not, write to the Free Software
  23  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  24  *
  25  */
  26
  27 #include <linux/io.h>
  28 #include <linux/slab.h>
  29 #include <linux/delay.h>
  30 #include <linux/ioport.h>
  31 #include <linux/errno.h>
  32 #include <linux/export.h>
  33 #include <sound/core.h>
  34 #include <sound/rawmidi.h>
  35
  36 #include "msnd.h"
  37
  38 #define MSNDMIDI_MODE_BIT_INPUT         0
  39 #define MSNDMIDI_MODE_BIT_OUTPUT                1
  40 #define MSNDMIDI_MODE_BIT_INPUT_TRIGGER 2
  41 #define MSNDMIDI_MODE_BIT_OUTPUT_TRIGGER        3
  42
  43 struct snd_msndmidi {
  44         struct snd_msnd *dev;
  45
  46         unsigned long mode;             /* MSNDMIDI_MODE_XXXX */
  47
  48         struct snd_rawmidi_substream *substream_input;
  49
  50         spinlock_t input_lock;
  51 };
  52
  53 /*
  54  * input/output open/close - protected by open_mutex in rawmidi.c
  55  */
  56 static int snd_msndmidi_input_open(struct snd_rawmidi_substream *substream)
  57 {
  58         struct snd_msndmidi *mpu;
  59
  60         snd_printdd("snd_msndmidi_input_open()\n");
  61
  62         mpu = substream->rmidi->private_data;
  63
  64         mpu->substream_input = substream;
  65
  66         snd_msnd_enable_irq(mpu->dev);
  67
  68         snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_START);
  69         set_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
  70         return 0;
  71 }
  72
  73 static int snd_msndmidi_input_close(struct snd_rawmidi_substream *substream)
  74 {
  75         struct snd_msndmidi *mpu;
  76
  77         mpu = substream->rmidi->private_data;
  78         snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_STOP);
  79         clear_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
  80         mpu->substream_input = NULL;
  81         snd_msnd_disable_irq(mpu->dev);
  82         return 0;
  83 }
  84
  85 static void snd_msndmidi_input_drop(struct snd_msndmidi *mpu)
  86 {
  87         u16 tail;
  88
  89         tail = readw(mpu->dev->MIDQ + JQS_wTail);
  90         writew(tail, mpu->dev->MIDQ + JQS_wHead);
  91 }
  92
  93 /*
  94  * trigger input
  95  */
  96 static void snd_msndmidi_input_trigger(struct snd_rawmidi_substream *substream,
  97                                         int up)
  98 {
  99         unsigned long flags;
 100         struct snd_msndmidi *mpu;
 101
 102         snd_printdd("snd_msndmidi_input_trigger(, %i)\n", up);
 103
 104         mpu = substream->rmidi->private_data;
 105         spin_lock_irqsave(&mpu->input_lock, flags);
 106         if (up) {
 107                 if (!test_and_set_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER,
 108                                       &mpu->mode))
 109                         snd_msndmidi_input_drop(mpu);
 110         } else {
 111                 clear_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
 112         }
 113         spin_unlock_irqrestore(&mpu->input_lock, flags);
 114         if (up)
 115                 snd_msndmidi_input_read(mpu);
 116 }
 117
 118 void snd_msndmidi_input_read(void *mpuv)
 119 {
 120         unsigned long flags;
 121         struct snd_msndmidi *mpu = mpuv;
 122         void *pwMIDQData = mpu->dev->mappedbase + MIDQ_DATA_BUFF;
 123         u16 head, tail, size;
 124
 125         spin_lock_irqsave(&mpu->input_lock, flags);
 126         head = readw(mpu->dev->MIDQ + JQS_wHead);
 127         tail = readw(mpu->dev->MIDQ + JQS_wTail);
 128         size = readw(mpu->dev->MIDQ + JQS_wSize);
 129         if (head > size || tail > size)
 130                 goto out;
 131         while (head != tail) {
 132                 unsigned char val = readw(pwMIDQData + 2 * head);
 133
 134                 if (test_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
 135                         snd_rawmidi_receive(mpu->substream_input, &val, 1);
 136                 if (++head > size)
 137                         head = 0;
 138                 writew(head, mpu->dev->MIDQ + JQS_wHead);
 139         }
 140  out:
 141         spin_unlock_irqrestore(&mpu->input_lock, flags);
 142 }
 143 EXPORT_SYMBOL(snd_msndmidi_input_read);
 144
 145 static const struct snd_rawmidi_ops snd_msndmidi_input = {
 146         .open =         snd_msndmidi_input_open,
 147         .close =        snd_msndmidi_input_close,
 148         .trigger =      snd_msndmidi_input_trigger,
 149 };
 150
 151 static void snd_msndmidi_free(struct snd_rawmidi *rmidi)
 152 {
 153         struct snd_msndmidi *mpu = rmidi->private_data;
 154         kfree(mpu);
 155 }
 156
 157 int snd_msndmidi_new(struct snd_card *card, int device)
 158 {
 159         struct snd_msnd *chip = card->private_data;
 160         struct snd_msndmidi *mpu;
 161         struct snd_rawmidi *rmidi;
 162         int err;
 163
 164         err = snd_rawmidi_new(card, "MSND-MIDI", device, 1, 1, &rmidi);
 165         if (err < 0)
 166                 return err;
 167         mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
 168         if (mpu == NULL) {
 169                 snd_device_free(card, rmidi);
 170                 return -ENOMEM;
 171         }
 172         mpu->dev = chip;
 173         chip->msndmidi_mpu = mpu;
 174         rmidi->private_data = mpu;
 175         rmidi->private_free = snd_msndmidi_free;
 176         spin_lock_init(&mpu->input_lock);
 177         strcpy(rmidi->name, "MSND MIDI");
 178         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 179                             &snd_msndmidi_input);
 180         rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
 181         return 0;
 182 }