cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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msnd_midi.c (4282B)

      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
     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.c
     40 */
     41static int snd_msndmidi_input_open(struct snd_rawmidi_substream *substream)
     42{
     43	struct snd_msndmidi *mpu;
     44
     45	snd_printdd("snd_msndmidi_input_open()\n");
     46
     47	mpu = substream->rmidi->private_data;
     48
     49	mpu->substream_input = substream;
     50
     51	snd_msnd_enable_irq(mpu->dev);
     52
     53	snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_START);
     54	set_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
     55	return 0;
     56}
     57
     58static int snd_msndmidi_input_close(struct snd_rawmidi_substream *substream)
     59{
     60	struct snd_msndmidi *mpu;
     61
     62	mpu = substream->rmidi->private_data;
     63	snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_STOP);
     64	clear_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
     65	mpu->substream_input = NULL;
     66	snd_msnd_disable_irq(mpu->dev);
     67	return 0;
     68}
     69
     70static void snd_msndmidi_input_drop(struct snd_msndmidi *mpu)
     71{
     72	u16 tail;
     73
     74	tail = readw(mpu->dev->MIDQ + JQS_wTail);
     75	writew(tail, mpu->dev->MIDQ + JQS_wHead);
     76}
     77
     78/*
     79 * trigger input
     80 */
     81static void snd_msndmidi_input_trigger(struct snd_rawmidi_substream *substream,
     82					int up)
     83{
     84	unsigned long flags;
     85	struct snd_msndmidi *mpu;
     86
     87	snd_printdd("snd_msndmidi_input_trigger(, %i)\n", up);
     88
     89	mpu = substream->rmidi->private_data;
     90	spin_lock_irqsave(&mpu->input_lock, flags);
     91	if (up) {
     92		if (!test_and_set_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER,
     93				      &mpu->mode))
     94			snd_msndmidi_input_drop(mpu);
     95	} else {
     96		clear_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
     97	}
     98	spin_unlock_irqrestore(&mpu->input_lock, flags);
     99	if (up)
    100		snd_msndmidi_input_read(mpu);
    101}
    102
    103void snd_msndmidi_input_read(void *mpuv)
    104{
    105	unsigned long flags;
    106	struct snd_msndmidi *mpu = mpuv;
    107	void __iomem *pwMIDQData = mpu->dev->mappedbase + MIDQ_DATA_BUFF;
    108	u16 head, tail, size;
    109
    110	spin_lock_irqsave(&mpu->input_lock, flags);
    111	head = readw(mpu->dev->MIDQ + JQS_wHead);
    112	tail = readw(mpu->dev->MIDQ + JQS_wTail);
    113	size = readw(mpu->dev->MIDQ + JQS_wSize);
    114	if (head > size || tail > size)
    115		goto out;
    116	while (head != tail) {
    117		unsigned char val = readw(pwMIDQData + 2 * head);
    118
    119		if (test_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
    120			snd_rawmidi_receive(mpu->substream_input, &val, 1);
    121		if (++head > size)
    122			head = 0;
    123		writew(head, mpu->dev->MIDQ + JQS_wHead);
    124	}
    125 out:
    126	spin_unlock_irqrestore(&mpu->input_lock, flags);
    127}
    128EXPORT_SYMBOL(snd_msndmidi_input_read);
    129
    130static const struct snd_rawmidi_ops snd_msndmidi_input = {
    131	.open =		snd_msndmidi_input_open,
    132	.close =	snd_msndmidi_input_close,
    133	.trigger =	snd_msndmidi_input_trigger,
    134};
    135
    136static void snd_msndmidi_free(struct snd_rawmidi *rmidi)
    137{
    138	struct snd_msndmidi *mpu = rmidi->private_data;
    139	kfree(mpu);
    140}
    141
    142int snd_msndmidi_new(struct snd_card *card, int device)
    143{
    144	struct snd_msnd *chip = card->private_data;
    145	struct snd_msndmidi *mpu;
    146	struct snd_rawmidi *rmidi;
    147	int err;
    148
    149	err = snd_rawmidi_new(card, "MSND-MIDI", device, 1, 1, &rmidi);
    150	if (err < 0)
    151		return err;
    152	mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
    153	if (mpu == NULL) {
    154		snd_device_free(card, rmidi);
    155		return -ENOMEM;
    156	}
    157	mpu->dev = chip;
    158	chip->msndmidi_mpu = mpu;
    159	rmidi->private_data = mpu;
    160	rmidi->private_free = snd_msndmidi_free;
    161	spin_lock_init(&mpu->input_lock);
    162	strcpy(rmidi->name, "MSND MIDI");
    163	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
    164			    &snd_msndmidi_input);
    165	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
    166	return 0;
    167}