xref: /linux/sound/drivers/portman2x4.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Driver for Midiman Portman2x4 parallel port midi interface
4  *
5  *   Copyright (c) by Levent Guendogdu <levon@feature-it.com>
6  *
7  * ChangeLog
8  * Jan 24 2007 Matthias Koenig <mkoenig@suse.de>
9  *      - cleanup and rewrite
10  * Sep 30 2004 Tobias Gehrig <tobias@gehrig.tk>
11  *      - source code cleanup
12  * Sep 03 2004 Tobias Gehrig <tobias@gehrig.tk>
13  *      - fixed compilation problem with alsa 1.0.6a (removed MODULE_CLASSES,
14  *        MODULE_PARM_SYNTAX and changed MODULE_DEVICES to
15  *        MODULE_SUPPORTED_DEVICE)
16  * Mar 24 2004 Tobias Gehrig <tobias@gehrig.tk>
17  *      - added 2.6 kernel support
18  * Mar 18 2004 Tobias Gehrig <tobias@gehrig.tk>
19  *      - added parport_unregister_driver to the startup routine if the driver fails to detect a portman
20  *      - added support for all 4 output ports in portman_putmidi
21  * Mar 17 2004 Tobias Gehrig <tobias@gehrig.tk>
22  *      - added checks for opened input device in interrupt handler
23  * Feb 20 2004 Tobias Gehrig <tobias@gehrig.tk>
24  *      - ported from alsa 0.5 to 1.0
25  */
26 
27 #include <linux/init.h>
28 #include <linux/platform_device.h>
29 #include <linux/parport.h>
30 #include <linux/spinlock.h>
31 #include <linux/delay.h>
32 #include <linux/slab.h>
33 #include <linux/module.h>
34 #include <sound/core.h>
35 #include <sound/initval.h>
36 #include <sound/rawmidi.h>
37 #include <sound/control.h>
38 
39 #define CARD_NAME "Portman 2x4"
40 #define DRIVER_NAME "portman"
41 #define PLATFORM_DRIVER "snd_portman2x4"
42 
43 static int index[SNDRV_CARDS]  = SNDRV_DEFAULT_IDX;
44 static char *id[SNDRV_CARDS]   = SNDRV_DEFAULT_STR;
45 static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;
46 
47 static struct platform_device *platform_devices[SNDRV_CARDS];
48 static int device_count;
49 
50 module_param_array(index, int, NULL, 0444);
51 MODULE_PARM_DESC(index, "Index value for " CARD_NAME " soundcard.");
52 module_param_array(id, charp, NULL, 0444);
53 MODULE_PARM_DESC(id, "ID string for " CARD_NAME " soundcard.");
54 module_param_array(enable, bool, NULL, 0444);
55 MODULE_PARM_DESC(enable, "Enable " CARD_NAME " soundcard.");
56 
57 MODULE_AUTHOR("Levent Guendogdu, Tobias Gehrig, Matthias Koenig");
58 MODULE_DESCRIPTION("Midiman Portman2x4");
59 MODULE_LICENSE("GPL");
60 
61 /*********************************************************************
62  * Chip specific
63  *********************************************************************/
64 #define PORTMAN_NUM_INPUT_PORTS 2
65 #define PORTMAN_NUM_OUTPUT_PORTS 4
66 
67 struct portman {
68 	spinlock_t reg_lock;
69 	struct snd_card *card;
70 	struct snd_rawmidi *rmidi;
71 	struct pardevice *pardev;
72 	int open_count;
73 	int mode[PORTMAN_NUM_INPUT_PORTS];
74 	struct snd_rawmidi_substream *midi_input[PORTMAN_NUM_INPUT_PORTS];
75 };
76 
77 static int portman_free(struct portman *pm)
78 {
79 	kfree(pm);
80 	return 0;
81 }
82 
83 static int portman_create(struct snd_card *card,
84 			  struct pardevice *pardev,
85 			  struct portman **rchip)
86 {
87 	struct portman *pm;
88 
89 	*rchip = NULL;
90 
91 	pm = kzalloc(sizeof(struct portman), GFP_KERNEL);
92 	if (pm == NULL)
93 		return -ENOMEM;
94 
95 	/* Init chip specific data */
96 	spin_lock_init(&pm->reg_lock);
97 	pm->card = card;
98 	pm->pardev = pardev;
99 
100 	*rchip = pm;
101 
102 	return 0;
103 }
104 
105 /*********************************************************************
106  * HW related constants
107  *********************************************************************/
108 
109 /* Standard PC parallel port status register equates. */
110 #define	PP_STAT_BSY   	0x80	/* Busy status.  Inverted. */
111 #define	PP_STAT_ACK   	0x40	/* Acknowledge.  Non-Inverted. */
112 #define	PP_STAT_POUT  	0x20	/* Paper Out.    Non-Inverted. */
113 #define	PP_STAT_SEL   	0x10	/* Select.       Non-Inverted. */
114 #define	PP_STAT_ERR   	0x08	/* Error.        Non-Inverted. */
115 
116 /* Standard PC parallel port command register equates. */
117 #define	PP_CMD_IEN  	0x10	/* IRQ Enable.   Non-Inverted. */
118 #define	PP_CMD_SELI 	0x08	/* Select Input. Inverted. */
119 #define	PP_CMD_INIT 	0x04	/* Init Printer. Non-Inverted. */
120 #define	PP_CMD_FEED 	0x02	/* Auto Feed.    Inverted. */
121 #define	PP_CMD_STB      0x01	/* Strobe.       Inverted. */
122 
123 /* Parallel Port Command Register as implemented by PCP2x4. */
124 #define	INT_EN	 	PP_CMD_IEN	/* Interrupt enable. */
125 #define	STROBE	        PP_CMD_STB	/* Command strobe. */
126 
127 /* The parallel port command register field (b1..b3) selects the
128  * various "registers" within the PC/P 2x4.  These are the internal
129  * address of these "registers" that must be written to the parallel
130  * port command register.
131  */
132 #define	RXDATA0		(0 << 1)	/* PCP RxData channel 0. */
133 #define	RXDATA1		(1 << 1)	/* PCP RxData channel 1. */
134 #define	GEN_CTL		(2 << 1)	/* PCP General Control Register. */
135 #define	SYNC_CTL 	(3 << 1)	/* PCP Sync Control Register. */
136 #define	TXDATA0		(4 << 1)	/* PCP TxData channel 0. */
137 #define	TXDATA1		(5 << 1)	/* PCP TxData channel 1. */
138 #define	TXDATA2		(6 << 1)	/* PCP TxData channel 2. */
139 #define	TXDATA3		(7 << 1)	/* PCP TxData channel 3. */
140 
141 /* Parallel Port Status Register as implemented by PCP2x4. */
142 #define	ESTB		PP_STAT_POUT	/* Echoed strobe. */
143 #define	INT_REQ         PP_STAT_ACK	/* Input data int request. */
144 #define	BUSY            PP_STAT_ERR	/* Interface Busy. */
145 
146 /* Parallel Port Status Register BUSY and SELECT lines are multiplexed
147  * between several functions.  Depending on which 2x4 "register" is
148  * currently selected (b1..b3), the BUSY and SELECT lines are
149  * assigned as follows:
150  *
151  *   SELECT LINE:                                                    A3 A2 A1
152  *                                                                   --------
153  */
154 #define	RXAVAIL		PP_STAT_SEL	/* Rx Available, channel 0.   0 0 0 */
155 //  RXAVAIL1    PP_STAT_SEL             /* Rx Available, channel 1.   0 0 1 */
156 #define	SYNC_STAT	PP_STAT_SEL	/* Reserved - Sync Status.    0 1 0 */
157 //                                      /* Reserved.                  0 1 1 */
158 #define	TXEMPTY		PP_STAT_SEL	/* Tx Empty, channel 0.       1 0 0 */
159 //      TXEMPTY1        PP_STAT_SEL     /* Tx Empty, channel 1.       1 0 1 */
160 //  TXEMPTY2    PP_STAT_SEL             /* Tx Empty, channel 2.       1 1 0 */
161 //  TXEMPTY3    PP_STAT_SEL             /* Tx Empty, channel 3.       1 1 1 */
162 
163 /*   BUSY LINE:                                                      A3 A2 A1
164  *                                                                   --------
165  */
166 #define	RXDATA		PP_STAT_BSY	/* Rx Input Data, channel 0.  0 0 0 */
167 //      RXDATA1         PP_STAT_BSY     /* Rx Input Data, channel 1.  0 0 1 */
168 #define	SYNC_DATA       PP_STAT_BSY	/* Reserved - Sync Data.      0 1 0 */
169 					/* Reserved.                  0 1 1 */
170 #define	DATA_ECHO       PP_STAT_BSY	/* Parallel Port Data Echo.   1 0 0 */
171 #define	A0_ECHO         PP_STAT_BSY	/* Address 0 Echo.            1 0 1 */
172 #define	A1_ECHO         PP_STAT_BSY	/* Address 1 Echo.            1 1 0 */
173 #define	A2_ECHO         PP_STAT_BSY	/* Address 2 Echo.            1 1 1 */
174 
175 #define PORTMAN2X4_MODE_INPUT_TRIGGERED	 0x01
176 
177 /*********************************************************************
178  * Hardware specific functions
179  *********************************************************************/
180 static inline void portman_write_command(struct portman *pm, u8 value)
181 {
182 	parport_write_control(pm->pardev->port, value);
183 }
184 
185 static inline u8 portman_read_status(struct portman *pm)
186 {
187 	return parport_read_status(pm->pardev->port);
188 }
189 
190 static inline void portman_write_data(struct portman *pm, u8 value)
191 {
192 	parport_write_data(pm->pardev->port, value);
193 }
194 
195 static void portman_write_midi(struct portman *pm,
196 			       int port, u8 mididata)
197 {
198 	int command = ((port + 4) << 1);
199 
200 	/* Get entering data byte and port number in BL and BH respectively.
201 	 * Set up Tx Channel address field for use with PP Cmd Register.
202 	 * Store address field in BH register.
203 	 * Inputs:      AH = Output port number (0..3).
204 	 *              AL = Data byte.
205 	 *    command = TXDATA0 | INT_EN;
206 	 * Align port num with address field (b1...b3),
207 	 * set address for TXDatax, Strobe=0
208 	 */
209 	command |= INT_EN;
210 
211 	/* Disable interrupts so that the process is not interrupted, then
212 	 * write the address associated with the current Tx channel to the
213 	 * PP Command Reg.  Do not set the Strobe signal yet.
214 	 */
215 
216 	do {
217 		portman_write_command(pm, command);
218 
219 		/* While the address lines settle, write parallel output data to
220 		 * PP Data Reg.  This has no effect until Strobe signal is asserted.
221 		 */
222 
223 		portman_write_data(pm, mididata);
224 
225 		/* If PCP channel's TxEmpty is set (TxEmpty is read through the PP
226 		 * Status Register), then go write data.  Else go back and wait.
227 		 */
228 	} while ((portman_read_status(pm) & TXEMPTY) != TXEMPTY);
229 
230 	/* TxEmpty is set.  Maintain PC/P destination address and assert
231 	 * Strobe through the PP Command Reg.  This will Strobe data into
232 	 * the PC/P transmitter and set the PC/P BUSY signal.
233 	 */
234 
235 	portman_write_command(pm, command | STROBE);
236 
237 	/* Wait for strobe line to settle and echo back through hardware.
238 	 * Once it has echoed back, assume that the address and data lines
239 	 * have settled!
240 	 */
241 
242 	while ((portman_read_status(pm) & ESTB) == 0)
243 		cpu_relax();
244 
245 	/* Release strobe and immediately re-allow interrupts. */
246 	portman_write_command(pm, command);
247 
248 	while ((portman_read_status(pm) & ESTB) == ESTB)
249 		cpu_relax();
250 
251 	/* PC/P BUSY is now set.  We must wait until BUSY resets itself.
252 	 * We'll reenable ints while we're waiting.
253 	 */
254 
255 	while ((portman_read_status(pm) & BUSY) == BUSY)
256 		cpu_relax();
257 
258 	/* Data sent. */
259 }
260 
261 
262 /*
263  *  Read MIDI byte from port
264  *  Attempt to read input byte from specified hardware input port (0..).
265  *  Return -1 if no data
266  */
267 static int portman_read_midi(struct portman *pm, int port)
268 {
269 	unsigned char midi_data = 0;
270 	unsigned char cmdout;	/* Saved address+IE bit. */
271 
272 	/* Make sure clocking edge is down before starting... */
273 	portman_write_data(pm, 0);	/* Make sure edge is down. */
274 
275 	/* Set destination address to PCP. */
276 	cmdout = (port << 1) | INT_EN;	/* Address + IE + No Strobe. */
277 	portman_write_command(pm, cmdout);
278 
279 	while ((portman_read_status(pm) & ESTB) == ESTB)
280 		cpu_relax();	/* Wait for strobe echo. */
281 
282 	/* After the address lines settle, check multiplexed RxAvail signal.
283 	 * If data is available, read it.
284 	 */
285 	if ((portman_read_status(pm) & RXAVAIL) == 0)
286 		return -1;	/* No data. */
287 
288 	/* Set the Strobe signal to enable the Rx clocking circuitry. */
289 	portman_write_command(pm, cmdout | STROBE);	/* Write address+IE+Strobe. */
290 
291 	while ((portman_read_status(pm) & ESTB) == 0)
292 		cpu_relax(); /* Wait for strobe echo. */
293 
294 	/* The first data bit (msb) is already sitting on the input line. */
295 	midi_data = (portman_read_status(pm) & 128);
296 	portman_write_data(pm, 1);	/* Cause rising edge, which shifts data. */
297 
298 	/* Data bit 6. */
299 	portman_write_data(pm, 0);	/* Cause falling edge while data settles. */
300 	midi_data |= (portman_read_status(pm) >> 1) & 64;
301 	portman_write_data(pm, 1);	/* Cause rising edge, which shifts data. */
302 
303 	/* Data bit 5. */
304 	portman_write_data(pm, 0);	/* Cause falling edge while data settles. */
305 	midi_data |= (portman_read_status(pm) >> 2) & 32;
306 	portman_write_data(pm, 1);	/* Cause rising edge, which shifts data. */
307 
308 	/* Data bit 4. */
309 	portman_write_data(pm, 0);	/* Cause falling edge while data settles. */
310 	midi_data |= (portman_read_status(pm) >> 3) & 16;
311 	portman_write_data(pm, 1);	/* Cause rising edge, which shifts data. */
312 
313 	/* Data bit 3. */
314 	portman_write_data(pm, 0);	/* Cause falling edge while data settles. */
315 	midi_data |= (portman_read_status(pm) >> 4) & 8;
316 	portman_write_data(pm, 1);	/* Cause rising edge, which shifts data. */
317 
318 	/* Data bit 2. */
319 	portman_write_data(pm, 0);	/* Cause falling edge while data settles. */
320 	midi_data |= (portman_read_status(pm) >> 5) & 4;
321 	portman_write_data(pm, 1);	/* Cause rising edge, which shifts data. */
322 
323 	/* Data bit 1. */
324 	portman_write_data(pm, 0);	/* Cause falling edge while data settles. */
325 	midi_data |= (portman_read_status(pm) >> 6) & 2;
326 	portman_write_data(pm, 1);	/* Cause rising edge, which shifts data. */
327 
328 	/* Data bit 0. */
329 	portman_write_data(pm, 0);	/* Cause falling edge while data settles. */
330 	midi_data |= (portman_read_status(pm) >> 7) & 1;
331 	portman_write_data(pm, 1);	/* Cause rising edge, which shifts data. */
332 	portman_write_data(pm, 0);	/* Return data clock low. */
333 
334 
335 	/* De-assert Strobe and return data. */
336 	portman_write_command(pm, cmdout);	/* Output saved address+IE. */
337 
338 	/* Wait for strobe echo. */
339 	while ((portman_read_status(pm) & ESTB) == ESTB)
340 		cpu_relax();
341 
342 	return (midi_data & 255);	/* Shift back and return value. */
343 }
344 
345 /*
346  *  Checks if any input data on the given channel is available
347  *  Checks RxAvail
348  */
349 static int portman_data_avail(struct portman *pm, int channel)
350 {
351 	int command = INT_EN;
352 	switch (channel) {
353 	case 0:
354 		command |= RXDATA0;
355 		break;
356 	case 1:
357 		command |= RXDATA1;
358 		break;
359 	}
360 	/* Write hardware (assumme STROBE=0) */
361 	portman_write_command(pm, command);
362 	/* Check multiplexed RxAvail signal */
363 	if ((portman_read_status(pm) & RXAVAIL) == RXAVAIL)
364 		return 1;	/* Data available */
365 
366 	/* No Data available */
367 	return 0;
368 }
369 
370 
371 /*
372  *  Flushes any input
373  */
374 static void portman_flush_input(struct portman *pm, unsigned char port)
375 {
376 	/* Local variable for counting things */
377 	unsigned int i = 0;
378 	unsigned char command = 0;
379 
380 	switch (port) {
381 	case 0:
382 		command = RXDATA0;
383 		break;
384 	case 1:
385 		command = RXDATA1;
386 		break;
387 	default:
388 		dev_warn(pm->card->dev, "%s Won't flush port %i\n",
389 			 __func__, port);
390 		return;
391 	}
392 
393 	/* Set address for specified channel in port and allow to settle. */
394 	portman_write_command(pm, command);
395 
396 	/* Assert the Strobe and wait for echo back. */
397 	portman_write_command(pm, command | STROBE);
398 
399 	/* Wait for ESTB */
400 	while ((portman_read_status(pm) & ESTB) == 0)
401 		cpu_relax();
402 
403 	/* Output clock cycles to the Rx circuitry. */
404 	portman_write_data(pm, 0);
405 
406 	/* Flush 250 bits... */
407 	for (i = 0; i < 250; i++) {
408 		portman_write_data(pm, 1);
409 		portman_write_data(pm, 0);
410 	}
411 
412 	/* Deassert the Strobe signal of the port and wait for it to settle. */
413 	portman_write_command(pm, command | INT_EN);
414 
415 	/* Wait for settling */
416 	while ((portman_read_status(pm) & ESTB) == ESTB)
417 		cpu_relax();
418 }
419 
420 static int portman_probe(struct parport *p)
421 {
422 	/* Initialize the parallel port data register.  Will set Rx clocks
423 	 * low in case we happen to be addressing the Rx ports at this time.
424 	 */
425 	/* 1 */
426 	parport_write_data(p, 0);
427 
428 	/* Initialize the parallel port command register, thus initializing
429 	 * hardware handshake lines to midi box:
430 	 *
431 	 *                                  Strobe = 0
432 	 *                                  Interrupt Enable = 0
433 	 */
434 	/* 2 */
435 	parport_write_control(p, 0);
436 
437 	/* Check if Portman PC/P 2x4 is out there. */
438 	/* 3 */
439 	parport_write_control(p, RXDATA0);	/* Write Strobe=0 to command reg. */
440 
441 	/* Check for ESTB to be clear */
442 	/* 4 */
443 	if ((parport_read_status(p) & ESTB) == ESTB)
444 		return 1;	/* CODE 1 - Strobe Failure. */
445 
446 	/* Set for RXDATA0 where no damage will be done. */
447 	/* 5 */
448 	parport_write_control(p, RXDATA0 | STROBE);	/* Write Strobe=1 to command reg. */
449 
450 	/* 6 */
451 	if ((parport_read_status(p) & ESTB) != ESTB)
452 		return 1;	/* CODE 1 - Strobe Failure. */
453 
454 	/* 7 */
455 	parport_write_control(p, 0);	/* Reset Strobe=0. */
456 
457 	/* Check if Tx circuitry is functioning properly.  If initialized
458 	 * unit TxEmpty is false, send out char and see if it goes true.
459 	 */
460 	/* 8 */
461 	parport_write_control(p, TXDATA0);	/* Tx channel 0, strobe off. */
462 
463 	/* If PCP channel's TxEmpty is set (TxEmpty is read through the PP
464 	 * Status Register), then go write data.  Else go back and wait.
465 	 */
466 	/* 9 */
467 	if ((parport_read_status(p) & TXEMPTY) == 0)
468 		return 2;
469 
470 	/* Return OK status. */
471 	return 0;
472 }
473 
474 static int portman_device_init(struct portman *pm)
475 {
476 	portman_flush_input(pm, 0);
477 	portman_flush_input(pm, 1);
478 
479 	return 0;
480 }
481 
482 /*********************************************************************
483  * Rawmidi
484  *********************************************************************/
485 static int snd_portman_midi_open(struct snd_rawmidi_substream *substream)
486 {
487 	return 0;
488 }
489 
490 static int snd_portman_midi_close(struct snd_rawmidi_substream *substream)
491 {
492 	return 0;
493 }
494 
495 static void snd_portman_midi_input_trigger(struct snd_rawmidi_substream *substream,
496 					   int up)
497 {
498 	struct portman *pm = substream->rmidi->private_data;
499 	unsigned long flags;
500 
501 	spin_lock_irqsave(&pm->reg_lock, flags);
502 	if (up)
503 		pm->mode[substream->number] |= PORTMAN2X4_MODE_INPUT_TRIGGERED;
504 	else
505 		pm->mode[substream->number] &= ~PORTMAN2X4_MODE_INPUT_TRIGGERED;
506 	spin_unlock_irqrestore(&pm->reg_lock, flags);
507 }
508 
509 static void snd_portman_midi_output_trigger(struct snd_rawmidi_substream *substream,
510 					    int up)
511 {
512 	struct portman *pm = substream->rmidi->private_data;
513 	unsigned long flags;
514 	unsigned char byte;
515 
516 	spin_lock_irqsave(&pm->reg_lock, flags);
517 	if (up) {
518 		while ((snd_rawmidi_transmit(substream, &byte, 1) == 1))
519 			portman_write_midi(pm, substream->number, byte);
520 	}
521 	spin_unlock_irqrestore(&pm->reg_lock, flags);
522 }
523 
524 static const struct snd_rawmidi_ops snd_portman_midi_output = {
525 	.open =		snd_portman_midi_open,
526 	.close =	snd_portman_midi_close,
527 	.trigger =	snd_portman_midi_output_trigger,
528 };
529 
530 static const struct snd_rawmidi_ops snd_portman_midi_input = {
531 	.open =		snd_portman_midi_open,
532 	.close =	snd_portman_midi_close,
533 	.trigger =	snd_portman_midi_input_trigger,
534 };
535 
536 /* Create and initialize the rawmidi component */
537 static int snd_portman_rawmidi_create(struct snd_card *card)
538 {
539 	struct portman *pm = card->private_data;
540 	struct snd_rawmidi *rmidi;
541 	struct snd_rawmidi_substream *substream;
542 	int err;
543 
544 	err = snd_rawmidi_new(card, CARD_NAME, 0,
545 			      PORTMAN_NUM_OUTPUT_PORTS,
546 			      PORTMAN_NUM_INPUT_PORTS,
547 			      &rmidi);
548 	if (err < 0)
549 		return err;
550 
551 	rmidi->private_data = pm;
552 	strcpy(rmidi->name, CARD_NAME);
553 	rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
554 		            SNDRV_RAWMIDI_INFO_INPUT |
555                             SNDRV_RAWMIDI_INFO_DUPLEX;
556 
557 	pm->rmidi = rmidi;
558 
559 	/* register rawmidi ops */
560 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
561 			    &snd_portman_midi_output);
562 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
563 			    &snd_portman_midi_input);
564 
565 	/* name substreams */
566 	/* output */
567 	list_for_each_entry(substream,
568 			    &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams,
569 			    list) {
570 		sprintf(substream->name,
571 			"Portman2x4 %d", substream->number+1);
572 	}
573 	/* input */
574 	list_for_each_entry(substream,
575 			    &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams,
576 			    list) {
577 		pm->midi_input[substream->number] = substream;
578 		sprintf(substream->name,
579 			"Portman2x4 %d", substream->number+1);
580 	}
581 
582 	return err;
583 }
584 
585 /*********************************************************************
586  * parport stuff
587  *********************************************************************/
588 static void snd_portman_interrupt(void *userdata)
589 {
590 	unsigned char midivalue = 0;
591 	struct portman *pm = ((struct snd_card*)userdata)->private_data;
592 
593 	spin_lock(&pm->reg_lock);
594 
595 	/* While any input data is waiting */
596 	while ((portman_read_status(pm) & INT_REQ) == INT_REQ) {
597 		/* If data available on channel 0,
598 		   read it and stuff it into the queue. */
599 		if (portman_data_avail(pm, 0)) {
600 			/* Read Midi */
601 			midivalue = portman_read_midi(pm, 0);
602 			/* put midi into queue... */
603 			if (pm->mode[0] & PORTMAN2X4_MODE_INPUT_TRIGGERED)
604 				snd_rawmidi_receive(pm->midi_input[0],
605 						    &midivalue, 1);
606 
607 		}
608 		/* If data available on channel 1,
609 		   read it and stuff it into the queue. */
610 		if (portman_data_avail(pm, 1)) {
611 			/* Read Midi */
612 			midivalue = portman_read_midi(pm, 1);
613 			/* put midi into queue... */
614 			if (pm->mode[1] & PORTMAN2X4_MODE_INPUT_TRIGGERED)
615 				snd_rawmidi_receive(pm->midi_input[1],
616 						    &midivalue, 1);
617 		}
618 
619 	}
620 
621 	spin_unlock(&pm->reg_lock);
622 }
623 
624 static void snd_portman_attach(struct parport *p)
625 {
626 	struct platform_device *device;
627 
628 	device = platform_device_alloc(PLATFORM_DRIVER, device_count);
629 	if (!device)
630 		return;
631 
632 	/* Temporary assignment to forward the parport */
633 	platform_set_drvdata(device, p);
634 
635 	if (platform_device_add(device) < 0) {
636 		platform_device_put(device);
637 		return;
638 	}
639 
640 	/* Since we dont get the return value of probe
641 	 * We need to check if device probing succeeded or not */
642 	if (!platform_get_drvdata(device)) {
643 		platform_device_unregister(device);
644 		return;
645 	}
646 
647 	/* register device in global table */
648 	platform_devices[device_count] = device;
649 	device_count++;
650 }
651 
652 static void snd_portman_detach(struct parport *p)
653 {
654 	/* nothing to do here */
655 }
656 
657 static int snd_portman_dev_probe(struct pardevice *pardev)
658 {
659 	if (strcmp(pardev->name, DRIVER_NAME))
660 		return -ENODEV;
661 
662 	return 0;
663 }
664 
665 static struct parport_driver portman_parport_driver = {
666 	.name		= "portman2x4",
667 	.probe		= snd_portman_dev_probe,
668 	.match_port	= snd_portman_attach,
669 	.detach		= snd_portman_detach,
670 };
671 
672 /*********************************************************************
673  * platform stuff
674  *********************************************************************/
675 static void snd_portman_card_private_free(struct snd_card *card)
676 {
677 	struct portman *pm = card->private_data;
678 	struct pardevice *pardev = pm->pardev;
679 
680 	if (pardev) {
681 		parport_release(pardev);
682 		parport_unregister_device(pardev);
683 	}
684 
685 	portman_free(pm);
686 }
687 
688 static int snd_portman_probe(struct platform_device *pdev)
689 {
690 	struct pardevice *pardev;
691 	struct parport *p;
692 	int dev = pdev->id;
693 	struct snd_card *card = NULL;
694 	struct portman *pm = NULL;
695 	int err;
696 	struct pardev_cb portman_cb = {
697 		.preempt = NULL,
698 		.wakeup = NULL,
699 		.irq_func = snd_portman_interrupt,	/* ISR */
700 		.flags = PARPORT_DEV_EXCL,		/* flags */
701 	};
702 
703 	p = platform_get_drvdata(pdev);
704 	platform_set_drvdata(pdev, NULL);
705 
706 	if (dev >= SNDRV_CARDS)
707 		return -ENODEV;
708 	if (!enable[dev])
709 		return -ENOENT;
710 
711 	err = snd_card_new(&pdev->dev, index[dev], id[dev], THIS_MODULE,
712 			   0, &card);
713 	if (err < 0) {
714 		dev_dbg(&pdev->dev, "Cannot create card\n");
715 		return err;
716 	}
717 	strcpy(card->driver, DRIVER_NAME);
718 	strcpy(card->shortname, CARD_NAME);
719 	sprintf(card->longname,  "%s at 0x%lx, irq %i",
720 		card->shortname, p->base, p->irq);
721 
722 	portman_cb.private = card;			   /* private */
723 	pardev = parport_register_dev_model(p,		   /* port */
724 					    DRIVER_NAME,   /* name */
725 					    &portman_cb,   /* callbacks */
726 					    pdev->id);	   /* device number */
727 	if (pardev == NULL) {
728 		dev_dbg(card->dev, "Cannot register pardevice\n");
729 		err = -EIO;
730 		goto __err;
731 	}
732 
733 	/* claim parport */
734 	if (parport_claim(pardev)) {
735 		dev_dbg(card->dev, "Cannot claim parport 0x%lx\n", pardev->port->base);
736 		err = -EIO;
737 		goto free_pardev;
738 	}
739 
740 	err = portman_create(card, pardev, &pm);
741 	if (err < 0) {
742 		dev_dbg(card->dev, "Cannot create main component\n");
743 		goto release_pardev;
744 	}
745 	card->private_data = pm;
746 	card->private_free = snd_portman_card_private_free;
747 
748 	err = portman_probe(p);
749 	if (err) {
750 		err = -EIO;
751 		goto __err;
752 	}
753 
754 	err = snd_portman_rawmidi_create(card);
755 	if (err < 0) {
756 		dev_dbg(card->dev, "Creating Rawmidi component failed\n");
757 		goto __err;
758 	}
759 
760 	/* init device */
761 	err = portman_device_init(pm);
762 	if (err < 0)
763 		goto __err;
764 
765 	platform_set_drvdata(pdev, card);
766 
767 	/* At this point card will be usable */
768 	err = snd_card_register(card);
769 	if (err < 0) {
770 		dev_dbg(card->dev, "Cannot register card\n");
771 		goto __err;
772 	}
773 
774 	dev_info(card->dev, "Portman 2x4 on 0x%lx\n", p->base);
775 	return 0;
776 
777 release_pardev:
778 	parport_release(pardev);
779 free_pardev:
780 	parport_unregister_device(pardev);
781 __err:
782 	snd_card_free(card);
783 	return err;
784 }
785 
786 static void snd_portman_remove(struct platform_device *pdev)
787 {
788 	struct snd_card *card = platform_get_drvdata(pdev);
789 
790 	if (card)
791 		snd_card_free(card);
792 }
793 
794 
795 static struct platform_driver snd_portman_driver = {
796 	.probe  = snd_portman_probe,
797 	.remove_new = snd_portman_remove,
798 	.driver = {
799 		.name = PLATFORM_DRIVER,
800 	}
801 };
802 
803 /*********************************************************************
804  * module init stuff
805  *********************************************************************/
806 static void snd_portman_unregister_all(void)
807 {
808 	int i;
809 
810 	for (i = 0; i < SNDRV_CARDS; ++i) {
811 		if (platform_devices[i]) {
812 			platform_device_unregister(platform_devices[i]);
813 			platform_devices[i] = NULL;
814 		}
815 	}
816 	platform_driver_unregister(&snd_portman_driver);
817 	parport_unregister_driver(&portman_parport_driver);
818 }
819 
820 static int __init snd_portman_module_init(void)
821 {
822 	int err;
823 
824 	err = platform_driver_register(&snd_portman_driver);
825 	if (err < 0)
826 		return err;
827 
828 	if (parport_register_driver(&portman_parport_driver) != 0) {
829 		platform_driver_unregister(&snd_portman_driver);
830 		return -EIO;
831 	}
832 
833 	if (device_count == 0) {
834 		snd_portman_unregister_all();
835 		return -ENODEV;
836 	}
837 
838 	return 0;
839 }
840 
841 static void __exit snd_portman_module_exit(void)
842 {
843 	snd_portman_unregister_all();
844 }
845 
846 module_init(snd_portman_module_init);
847 module_exit(snd_portman_module_exit);
848