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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ca_midi.c (7971B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/* 
      3 *  Copyright 10/16/2005 Tilman Kranz <tilde@tk-sls.de>
      4 *  Creative Audio MIDI, for the CA0106 Driver
      5 *  Version: 0.0.1
      6 *
      7 *  Changelog:
      8 *    Implementation is based on mpu401 and emu10k1x and
      9 *    tested with ca0106.
     10 *    mpu401: Copyright (c) by Jaroslav Kysela <perex@perex.cz>
     11 *    emu10k1x: Copyright (c) by Francisco Moraes <fmoraes@nc.rr.com>
     12 */
     13
     14#include <linux/spinlock.h>
     15#include <sound/core.h>
     16#include <sound/rawmidi.h>
     17
     18#include "ca_midi.h"
     19
     20#define ca_midi_write_data(midi, data)	midi->write(midi, data, 0)
     21#define ca_midi_write_cmd(midi, data)	midi->write(midi, data, 1)
     22#define ca_midi_read_data(midi)		midi->read(midi, 0)
     23#define ca_midi_read_stat(midi)		midi->read(midi, 1)
     24#define ca_midi_input_avail(midi)	(!(ca_midi_read_stat(midi) & midi->input_avail))
     25#define ca_midi_output_ready(midi)	(!(ca_midi_read_stat(midi) & midi->output_ready))
     26
     27static void ca_midi_clear_rx(struct snd_ca_midi *midi)
     28{
     29	int timeout = 100000;
     30	for (; timeout > 0 && ca_midi_input_avail(midi); timeout--)
     31		ca_midi_read_data(midi);
     32#ifdef CONFIG_SND_DEBUG
     33	if (timeout <= 0)
     34		pr_err("ca_midi_clear_rx: timeout (status = 0x%x)\n",
     35			   ca_midi_read_stat(midi));
     36#endif
     37}
     38
     39static void ca_midi_interrupt(struct snd_ca_midi *midi, unsigned int status)
     40{
     41	unsigned char byte;
     42
     43	if (midi->rmidi == NULL) {
     44		midi->interrupt_disable(midi,midi->tx_enable | midi->rx_enable);
     45		return;
     46	}
     47
     48	spin_lock(&midi->input_lock);
     49	if ((status & midi->ipr_rx) && ca_midi_input_avail(midi)) {
     50		if (!(midi->midi_mode & CA_MIDI_MODE_INPUT)) {
     51			ca_midi_clear_rx(midi);
     52		} else {
     53			byte = ca_midi_read_data(midi);
     54			if(midi->substream_input)
     55				snd_rawmidi_receive(midi->substream_input, &byte, 1);
     56
     57
     58		}
     59	}
     60	spin_unlock(&midi->input_lock);
     61
     62	spin_lock(&midi->output_lock);
     63	if ((status & midi->ipr_tx) && ca_midi_output_ready(midi)) {
     64		if (midi->substream_output &&
     65		    snd_rawmidi_transmit(midi->substream_output, &byte, 1) == 1) {
     66			ca_midi_write_data(midi, byte);
     67		} else {
     68			midi->interrupt_disable(midi,midi->tx_enable);
     69		}
     70	}
     71	spin_unlock(&midi->output_lock);
     72
     73}
     74
     75static void ca_midi_cmd(struct snd_ca_midi *midi, unsigned char cmd, int ack)
     76{
     77	unsigned long flags;
     78	int timeout, ok;
     79
     80	spin_lock_irqsave(&midi->input_lock, flags);
     81	ca_midi_write_data(midi, 0x00);
     82	/* ca_midi_clear_rx(midi); */
     83
     84	ca_midi_write_cmd(midi, cmd);
     85	if (ack) {
     86		ok = 0;
     87		timeout = 10000;
     88		while (!ok && timeout-- > 0) {
     89			if (ca_midi_input_avail(midi)) {
     90				if (ca_midi_read_data(midi) == midi->ack)
     91					ok = 1;
     92			}
     93		}
     94		if (!ok && ca_midi_read_data(midi) == midi->ack)
     95			ok = 1;
     96	} else {
     97		ok = 1;
     98	}
     99	spin_unlock_irqrestore(&midi->input_lock, flags);
    100	if (!ok)
    101		pr_err("ca_midi_cmd: 0x%x failed at 0x%x (status = 0x%x, data = 0x%x)!!!\n",
    102			   cmd,
    103			   midi->get_dev_id_port(midi->dev_id),
    104			   ca_midi_read_stat(midi),
    105			   ca_midi_read_data(midi));
    106}
    107
    108static int ca_midi_input_open(struct snd_rawmidi_substream *substream)
    109{
    110	struct snd_ca_midi *midi = substream->rmidi->private_data;
    111	unsigned long flags;
    112	
    113	if (snd_BUG_ON(!midi->dev_id))
    114		return -ENXIO;
    115	spin_lock_irqsave(&midi->open_lock, flags);
    116	midi->midi_mode |= CA_MIDI_MODE_INPUT;
    117	midi->substream_input = substream;
    118	if (!(midi->midi_mode & CA_MIDI_MODE_OUTPUT)) {
    119		spin_unlock_irqrestore(&midi->open_lock, flags);
    120		ca_midi_cmd(midi, midi->reset, 1);
    121		ca_midi_cmd(midi, midi->enter_uart, 1);
    122	} else {
    123		spin_unlock_irqrestore(&midi->open_lock, flags);
    124	}
    125	return 0;
    126}
    127
    128static int ca_midi_output_open(struct snd_rawmidi_substream *substream)
    129{
    130	struct snd_ca_midi *midi = substream->rmidi->private_data;
    131	unsigned long flags;
    132
    133	if (snd_BUG_ON(!midi->dev_id))
    134		return -ENXIO;
    135	spin_lock_irqsave(&midi->open_lock, flags);
    136	midi->midi_mode |= CA_MIDI_MODE_OUTPUT;
    137	midi->substream_output = substream;
    138	if (!(midi->midi_mode & CA_MIDI_MODE_INPUT)) {
    139		spin_unlock_irqrestore(&midi->open_lock, flags);
    140		ca_midi_cmd(midi, midi->reset, 1);
    141		ca_midi_cmd(midi, midi->enter_uart, 1);
    142	} else {
    143		spin_unlock_irqrestore(&midi->open_lock, flags);
    144	}
    145	return 0;
    146}
    147
    148static int ca_midi_input_close(struct snd_rawmidi_substream *substream)
    149{
    150	struct snd_ca_midi *midi = substream->rmidi->private_data;
    151	unsigned long flags;
    152
    153	if (snd_BUG_ON(!midi->dev_id))
    154		return -ENXIO;
    155	spin_lock_irqsave(&midi->open_lock, flags);
    156	midi->interrupt_disable(midi,midi->rx_enable);
    157	midi->midi_mode &= ~CA_MIDI_MODE_INPUT;
    158	midi->substream_input = NULL;
    159	if (!(midi->midi_mode & CA_MIDI_MODE_OUTPUT)) {
    160		spin_unlock_irqrestore(&midi->open_lock, flags);
    161		ca_midi_cmd(midi, midi->reset, 0);
    162	} else {
    163		spin_unlock_irqrestore(&midi->open_lock, flags);
    164	}
    165	return 0;
    166}
    167
    168static int ca_midi_output_close(struct snd_rawmidi_substream *substream)
    169{
    170	struct snd_ca_midi *midi = substream->rmidi->private_data;
    171	unsigned long flags;
    172
    173	if (snd_BUG_ON(!midi->dev_id))
    174		return -ENXIO;
    175	
    176	spin_lock_irqsave(&midi->open_lock, flags);
    177
    178	midi->interrupt_disable(midi,midi->tx_enable);
    179	midi->midi_mode &= ~CA_MIDI_MODE_OUTPUT;
    180	midi->substream_output = NULL;
    181	
    182	if (!(midi->midi_mode & CA_MIDI_MODE_INPUT)) {
    183		spin_unlock_irqrestore(&midi->open_lock, flags);
    184		ca_midi_cmd(midi, midi->reset, 0);
    185	} else {
    186		spin_unlock_irqrestore(&midi->open_lock, flags);
    187	}
    188	return 0;
    189}
    190
    191static void ca_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)
    192{
    193	struct snd_ca_midi *midi = substream->rmidi->private_data;
    194
    195	if (snd_BUG_ON(!midi->dev_id))
    196		return;
    197
    198	if (up) {
    199		midi->interrupt_enable(midi,midi->rx_enable);
    200	} else {
    201		midi->interrupt_disable(midi, midi->rx_enable);
    202	}
    203}
    204
    205static void ca_midi_output_trigger(struct snd_rawmidi_substream *substream, int up)
    206{
    207	struct snd_ca_midi *midi = substream->rmidi->private_data;
    208	unsigned long flags;
    209
    210	if (snd_BUG_ON(!midi->dev_id))
    211		return;
    212
    213	if (up) {
    214		int max = 4;
    215		unsigned char byte;
    216
    217		spin_lock_irqsave(&midi->output_lock, flags);
    218	
    219		/* try to send some amount of bytes here before interrupts */
    220		while (max > 0) {
    221			if (ca_midi_output_ready(midi)) {
    222				if (!(midi->midi_mode & CA_MIDI_MODE_OUTPUT) ||
    223				    snd_rawmidi_transmit(substream, &byte, 1) != 1) {
    224					/* no more data */
    225					spin_unlock_irqrestore(&midi->output_lock, flags);
    226					return;
    227				}
    228				ca_midi_write_data(midi, byte);
    229				max--;
    230			} else {
    231				break;
    232			}
    233		}
    234
    235		spin_unlock_irqrestore(&midi->output_lock, flags);
    236		midi->interrupt_enable(midi,midi->tx_enable);
    237
    238	} else {
    239		midi->interrupt_disable(midi,midi->tx_enable);
    240	}
    241}
    242
    243static const struct snd_rawmidi_ops ca_midi_output =
    244{
    245	.open =		ca_midi_output_open,
    246	.close =	ca_midi_output_close,
    247	.trigger =	ca_midi_output_trigger,
    248};
    249
    250static const struct snd_rawmidi_ops ca_midi_input =
    251{
    252	.open =		ca_midi_input_open,
    253	.close =	ca_midi_input_close,
    254	.trigger =	ca_midi_input_trigger,
    255};
    256
    257static void ca_midi_free(struct snd_ca_midi *midi)
    258{
    259	midi->interrupt = NULL;
    260	midi->interrupt_enable = NULL;
    261	midi->interrupt_disable = NULL;
    262	midi->read = NULL;
    263	midi->write = NULL;
    264	midi->get_dev_id_card = NULL;
    265	midi->get_dev_id_port = NULL;
    266	midi->rmidi = NULL;
    267}
    268
    269static void ca_rmidi_free(struct snd_rawmidi *rmidi)
    270{
    271	ca_midi_free(rmidi->private_data);
    272}
    273
    274int ca_midi_init(void *dev_id, struct snd_ca_midi *midi, int device, char *name)
    275{
    276	struct snd_rawmidi *rmidi;
    277	int err;
    278
    279	err = snd_rawmidi_new(midi->get_dev_id_card(midi->dev_id), name, device, 1, 1, &rmidi);
    280	if (err < 0)
    281		return err;
    282
    283	midi->dev_id = dev_id;
    284	midi->interrupt = ca_midi_interrupt;
    285
    286	spin_lock_init(&midi->open_lock);
    287	spin_lock_init(&midi->input_lock);
    288	spin_lock_init(&midi->output_lock);
    289
    290	strcpy(rmidi->name, name);
    291	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &ca_midi_output);
    292	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &ca_midi_input);
    293	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT |
    294	                     SNDRV_RAWMIDI_INFO_INPUT |
    295	                     SNDRV_RAWMIDI_INFO_DUPLEX;
    296	rmidi->private_data = midi;
    297	rmidi->private_free = ca_rmidi_free;
    298	
    299	midi->rmidi = rmidi;
    300	return 0;
    301}
    302