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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>4 * Copyright (c) 2009 by Krzysztof Helt5 * Routines for control of MPU-401 in UART mode6 *7 * MPU-401 supports UART mode which is not capable generate transmit8 * interrupts thus output is done via polling. Also, if irq < 0, then9 * 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 024#define MSNDMIDI_MODE_BIT_OUTPUT 125#define MSNDMIDI_MODE_BIT_INPUT_TRIGGER 226#define MSNDMIDI_MODE_BIT_OUTPUT_TRIGGER 327 28struct 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.c40 */41static 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 56static 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 68static 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 input78 */79static 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 99void 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}124EXPORT_SYMBOL(snd_msndmidi_input_read);125 126static 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 132static void snd_msndmidi_free(struct snd_rawmidi *rmidi)133{134 struct snd_msndmidi *mpu = rmidi->private_data;135 kfree(mpu);136}137 138int 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