1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz> 4 * Copyright (c) 2009 by Krzysztof Helt 5 * Routines for control of MPU-401 in UART mode 6 * 7 * MPU-401 supports UART mode which is not capable generate transmit 8 * interrupts thus output is done via polling. Also, if irq < 0, then 9 * input is done also via polling. Do not expect good performance. 10 */ 11 12 #include <linux/io.h> 13 #include <linux/slab.h> 14 #include <linux/delay.h> 15 #include <linux/ioport.h> 16 #include <linux/errno.h> 17 #include <linux/export.h> 18 #include <sound/core.h> 19 #include <sound/rawmidi.h> 20 21 #include "msnd.h" 22 23 #define MSNDMIDI_MODE_BIT_INPUT 0 24 #define MSNDMIDI_MODE_BIT_OUTPUT 1 25 #define MSNDMIDI_MODE_BIT_INPUT_TRIGGER 2 26 #define MSNDMIDI_MODE_BIT_OUTPUT_TRIGGER 3 27 28 struct snd_msndmidi { 29 struct snd_msnd *dev; 30 31 unsigned long mode; /* MSNDMIDI_MODE_XXXX */ 32 33 struct snd_rawmidi_substream *substream_input; 34 35 spinlock_t input_lock; 36 }; 37 38 /* 39 * input/output open/close - protected by open_mutex in rawmidi.c 40 */ 41 static int snd_msndmidi_input_open(struct snd_rawmidi_substream *substream) 42 { 43 struct snd_msndmidi *mpu; 44 45 mpu = substream->rmidi->private_data; 46 47 mpu->substream_input = substream; 48 49 snd_msnd_enable_irq(mpu->dev); 50 51 snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_START); 52 set_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode); 53 return 0; 54 } 55 56 static int snd_msndmidi_input_close(struct snd_rawmidi_substream *substream) 57 { 58 struct snd_msndmidi *mpu; 59 60 mpu = substream->rmidi->private_data; 61 snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_STOP); 62 clear_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode); 63 mpu->substream_input = NULL; 64 snd_msnd_disable_irq(mpu->dev); 65 return 0; 66 } 67 68 static void snd_msndmidi_input_drop(struct snd_msndmidi *mpu) 69 { 70 u16 tail; 71 72 tail = readw(mpu->dev->MIDQ + JQS_wTail); 73 writew(tail, mpu->dev->MIDQ + JQS_wHead); 74 } 75 76 /* 77 * trigger input 78 */ 79 static void snd_msndmidi_input_trigger(struct snd_rawmidi_substream *substream, 80 int up) 81 { 82 unsigned long flags; 83 struct snd_msndmidi *mpu; 84 85 mpu = substream->rmidi->private_data; 86 spin_lock_irqsave(&mpu->input_lock, flags); 87 if (up) { 88 if (!test_and_set_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, 89 &mpu->mode)) 90 snd_msndmidi_input_drop(mpu); 91 } else { 92 clear_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode); 93 } 94 spin_unlock_irqrestore(&mpu->input_lock, flags); 95 if (up) 96 snd_msndmidi_input_read(mpu); 97 } 98 99 void snd_msndmidi_input_read(void *mpuv) 100 { 101 unsigned long flags; 102 struct snd_msndmidi *mpu = mpuv; 103 void __iomem *pwMIDQData = mpu->dev->mappedbase + MIDQ_DATA_BUFF; 104 u16 head, tail, size; 105 106 spin_lock_irqsave(&mpu->input_lock, flags); 107 head = readw(mpu->dev->MIDQ + JQS_wHead); 108 tail = readw(mpu->dev->MIDQ + JQS_wTail); 109 size = readw(mpu->dev->MIDQ + JQS_wSize); 110 if (head > size || tail > size) 111 goto out; 112 while (head != tail) { 113 unsigned char val = readw(pwMIDQData + 2 * head); 114 115 if (test_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode)) 116 snd_rawmidi_receive(mpu->substream_input, &val, 1); 117 if (++head > size) 118 head = 0; 119 writew(head, mpu->dev->MIDQ + JQS_wHead); 120 } 121 out: 122 spin_unlock_irqrestore(&mpu->input_lock, flags); 123 } 124 EXPORT_SYMBOL(snd_msndmidi_input_read); 125 126 static const struct snd_rawmidi_ops snd_msndmidi_input = { 127 .open = snd_msndmidi_input_open, 128 .close = snd_msndmidi_input_close, 129 .trigger = snd_msndmidi_input_trigger, 130 }; 131 132 static void snd_msndmidi_free(struct snd_rawmidi *rmidi) 133 { 134 struct snd_msndmidi *mpu = rmidi->private_data; 135 kfree(mpu); 136 } 137 138 int snd_msndmidi_new(struct snd_card *card, int device) 139 { 140 struct snd_msnd *chip = card->private_data; 141 struct snd_msndmidi *mpu; 142 struct snd_rawmidi *rmidi; 143 int err; 144 145 err = snd_rawmidi_new(card, "MSND-MIDI", device, 1, 1, &rmidi); 146 if (err < 0) 147 return err; 148 mpu = kzalloc(sizeof(*mpu), GFP_KERNEL); 149 if (mpu == NULL) { 150 snd_device_free(card, rmidi); 151 return -ENOMEM; 152 } 153 mpu->dev = chip; 154 chip->msndmidi_mpu = mpu; 155 rmidi->private_data = mpu; 156 rmidi->private_free = snd_msndmidi_free; 157 spin_lock_init(&mpu->input_lock); 158 strcpy(rmidi->name, "MSND MIDI"); 159 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, 160 &snd_msndmidi_input); 161 rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT; 162 return 0; 163 } 164