1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Driver for Midiman Portman2x4 parallel port midi interface
5 * Copyright (c) by Levent Guendogdu <levon@feature-it.com>
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
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>
39 #define CARD_NAME "Portman 2x4"
40 #define DRIVER_NAME "portman"
41 #define PLATFORM_DRIVER "snd_portman2x4"
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;
47 static struct platform_device *platform_devices[SNDRV_CARDS];
48 static int device_count;
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.");
57 MODULE_AUTHOR("Levent Guendogdu, Tobias Gehrig, Matthias Koenig");
58 MODULE_DESCRIPTION("Midiman Portman2x4");
59 MODULE_LICENSE("GPL");
61 /*********************************************************************
63 *********************************************************************/
64 #define PORTMAN_NUM_INPUT_PORTS 2
65 #define PORTMAN_NUM_OUTPUT_PORTS 4
69 struct snd_card *card;
70 struct snd_rawmidi *rmidi;
71 struct pardevice *pardev;
73 int mode[PORTMAN_NUM_INPUT_PORTS];
74 struct snd_rawmidi_substream *midi_input[PORTMAN_NUM_INPUT_PORTS];
77 static int portman_free(struct portman *pm)
83 static int portman_create(struct snd_card *card,
84 struct pardevice *pardev,
85 struct portman **rchip)
91 pm = kzalloc(sizeof(struct portman), GFP_KERNEL);
95 /* Init chip specific data */
96 spin_lock_init(&pm->reg_lock);
105 /*********************************************************************
106 * HW related constants
107 *********************************************************************/
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. */
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. */
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. */
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.
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. */
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. */
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:
151 * SELECT LINE: A3 A2 A1
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 */
163 /* BUSY LINE: A3 A2 A1
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 */
175 #define PORTMAN2X4_MODE_INPUT_TRIGGERED 0x01
177 /*********************************************************************
178 * Hardware specific functions
179 *********************************************************************/
180 static inline void portman_write_command(struct portman *pm, u8 value)
182 parport_write_control(pm->pardev->port, value);
185 static inline u8 portman_read_command(struct portman *pm)
187 return parport_read_control(pm->pardev->port);
190 static inline u8 portman_read_status(struct portman *pm)
192 return parport_read_status(pm->pardev->port);
195 static inline u8 portman_read_data(struct portman *pm)
197 return parport_read_data(pm->pardev->port);
200 static inline void portman_write_data(struct portman *pm, u8 value)
202 parport_write_data(pm->pardev->port, value);
205 static void portman_write_midi(struct portman *pm,
206 int port, u8 mididata)
208 int command = ((port + 4) << 1);
210 /* Get entering data byte and port number in BL and BH respectively.
211 * Set up Tx Channel address field for use with PP Cmd Register.
212 * Store address field in BH register.
213 * Inputs: AH = Output port number (0..3).
215 * command = TXDATA0 | INT_EN;
216 * Align port num with address field (b1...b3),
217 * set address for TXDatax, Strobe=0
221 /* Disable interrupts so that the process is not interrupted, then
222 * write the address associated with the current Tx channel to the
223 * PP Command Reg. Do not set the Strobe signal yet.
227 portman_write_command(pm, command);
229 /* While the address lines settle, write parallel output data to
230 * PP Data Reg. This has no effect until Strobe signal is asserted.
233 portman_write_data(pm, mididata);
235 /* If PCP channel's TxEmpty is set (TxEmpty is read through the PP
236 * Status Register), then go write data. Else go back and wait.
238 } while ((portman_read_status(pm) & TXEMPTY) != TXEMPTY);
240 /* TxEmpty is set. Maintain PC/P destination address and assert
241 * Strobe through the PP Command Reg. This will Strobe data into
242 * the PC/P transmitter and set the PC/P BUSY signal.
245 portman_write_command(pm, command | STROBE);
247 /* Wait for strobe line to settle and echo back through hardware.
248 * Once it has echoed back, assume that the address and data lines
252 while ((portman_read_status(pm) & ESTB) == 0)
255 /* Release strobe and immediately re-allow interrupts. */
256 portman_write_command(pm, command);
258 while ((portman_read_status(pm) & ESTB) == ESTB)
261 /* PC/P BUSY is now set. We must wait until BUSY resets itself.
262 * We'll reenable ints while we're waiting.
265 while ((portman_read_status(pm) & BUSY) == BUSY)
273 * Read MIDI byte from port
274 * Attempt to read input byte from specified hardware input port (0..).
275 * Return -1 if no data
277 static int portman_read_midi(struct portman *pm, int port)
279 unsigned char midi_data = 0;
280 unsigned char cmdout; /* Saved address+IE bit. */
282 /* Make sure clocking edge is down before starting... */
283 portman_write_data(pm, 0); /* Make sure edge is down. */
285 /* Set destination address to PCP. */
286 cmdout = (port << 1) | INT_EN; /* Address + IE + No Strobe. */
287 portman_write_command(pm, cmdout);
289 while ((portman_read_status(pm) & ESTB) == ESTB)
290 cpu_relax(); /* Wait for strobe echo. */
292 /* After the address lines settle, check multiplexed RxAvail signal.
293 * If data is available, read it.
295 if ((portman_read_status(pm) & RXAVAIL) == 0)
296 return -1; /* No data. */
298 /* Set the Strobe signal to enable the Rx clocking circuitry. */
299 portman_write_command(pm, cmdout | STROBE); /* Write address+IE+Strobe. */
301 while ((portman_read_status(pm) & ESTB) == 0)
302 cpu_relax(); /* Wait for strobe echo. */
304 /* The first data bit (msb) is already sitting on the input line. */
305 midi_data = (portman_read_status(pm) & 128);
306 portman_write_data(pm, 1); /* Cause rising edge, which shifts data. */
309 portman_write_data(pm, 0); /* Cause falling edge while data settles. */
310 midi_data |= (portman_read_status(pm) >> 1) & 64;
311 portman_write_data(pm, 1); /* Cause rising edge, which shifts data. */
314 portman_write_data(pm, 0); /* Cause falling edge while data settles. */
315 midi_data |= (portman_read_status(pm) >> 2) & 32;
316 portman_write_data(pm, 1); /* Cause rising edge, which shifts data. */
319 portman_write_data(pm, 0); /* Cause falling edge while data settles. */
320 midi_data |= (portman_read_status(pm) >> 3) & 16;
321 portman_write_data(pm, 1); /* Cause rising edge, which shifts data. */
324 portman_write_data(pm, 0); /* Cause falling edge while data settles. */
325 midi_data |= (portman_read_status(pm) >> 4) & 8;
326 portman_write_data(pm, 1); /* Cause rising edge, which shifts data. */
329 portman_write_data(pm, 0); /* Cause falling edge while data settles. */
330 midi_data |= (portman_read_status(pm) >> 5) & 4;
331 portman_write_data(pm, 1); /* Cause rising edge, which shifts data. */
334 portman_write_data(pm, 0); /* Cause falling edge while data settles. */
335 midi_data |= (portman_read_status(pm) >> 6) & 2;
336 portman_write_data(pm, 1); /* Cause rising edge, which shifts data. */
339 portman_write_data(pm, 0); /* Cause falling edge while data settles. */
340 midi_data |= (portman_read_status(pm) >> 7) & 1;
341 portman_write_data(pm, 1); /* Cause rising edge, which shifts data. */
342 portman_write_data(pm, 0); /* Return data clock low. */
345 /* De-assert Strobe and return data. */
346 portman_write_command(pm, cmdout); /* Output saved address+IE. */
348 /* Wait for strobe echo. */
349 while ((portman_read_status(pm) & ESTB) == ESTB)
352 return (midi_data & 255); /* Shift back and return value. */
356 * Checks if any input data on the given channel is available
359 static int portman_data_avail(struct portman *pm, int channel)
361 int command = INT_EN;
370 /* Write hardware (assumme STROBE=0) */
371 portman_write_command(pm, command);
372 /* Check multiplexed RxAvail signal */
373 if ((portman_read_status(pm) & RXAVAIL) == RXAVAIL)
374 return 1; /* Data available */
376 /* No Data available */
384 static void portman_flush_input(struct portman *pm, unsigned char port)
386 /* Local variable for counting things */
388 unsigned char command = 0;
398 snd_printk(KERN_WARNING
399 "portman_flush_input() Won't flush port %i\n",
404 /* Set address for specified channel in port and allow to settle. */
405 portman_write_command(pm, command);
407 /* Assert the Strobe and wait for echo back. */
408 portman_write_command(pm, command | STROBE);
411 while ((portman_read_status(pm) & ESTB) == 0)
414 /* Output clock cycles to the Rx circuitry. */
415 portman_write_data(pm, 0);
417 /* Flush 250 bits... */
418 for (i = 0; i < 250; i++) {
419 portman_write_data(pm, 1);
420 portman_write_data(pm, 0);
423 /* Deassert the Strobe signal of the port and wait for it to settle. */
424 portman_write_command(pm, command | INT_EN);
426 /* Wait for settling */
427 while ((portman_read_status(pm) & ESTB) == ESTB)
431 static int portman_probe(struct parport *p)
433 /* Initialize the parallel port data register. Will set Rx clocks
434 * low in case we happen to be addressing the Rx ports at this time.
437 parport_write_data(p, 0);
439 /* Initialize the parallel port command register, thus initializing
440 * hardware handshake lines to midi box:
443 * Interrupt Enable = 0
446 parport_write_control(p, 0);
448 /* Check if Portman PC/P 2x4 is out there. */
450 parport_write_control(p, RXDATA0); /* Write Strobe=0 to command reg. */
452 /* Check for ESTB to be clear */
454 if ((parport_read_status(p) & ESTB) == ESTB)
455 return 1; /* CODE 1 - Strobe Failure. */
457 /* Set for RXDATA0 where no damage will be done. */
459 parport_write_control(p, RXDATA0 | STROBE); /* Write Strobe=1 to command reg. */
462 if ((parport_read_status(p) & ESTB) != ESTB)
463 return 1; /* CODE 1 - Strobe Failure. */
466 parport_write_control(p, 0); /* Reset Strobe=0. */
468 /* Check if Tx circuitry is functioning properly. If initialized
469 * unit TxEmpty is false, send out char and see if it goes true.
472 parport_write_control(p, TXDATA0); /* Tx channel 0, strobe off. */
474 /* If PCP channel's TxEmpty is set (TxEmpty is read through the PP
475 * Status Register), then go write data. Else go back and wait.
478 if ((parport_read_status(p) & TXEMPTY) == 0)
481 /* Return OK status. */
485 static int portman_device_init(struct portman *pm)
487 portman_flush_input(pm, 0);
488 portman_flush_input(pm, 1);
493 /*********************************************************************
495 *********************************************************************/
496 static int snd_portman_midi_open(struct snd_rawmidi_substream *substream)
501 static int snd_portman_midi_close(struct snd_rawmidi_substream *substream)
506 static void snd_portman_midi_input_trigger(struct snd_rawmidi_substream *substream,
509 struct portman *pm = substream->rmidi->private_data;
512 spin_lock_irqsave(&pm->reg_lock, flags);
514 pm->mode[substream->number] |= PORTMAN2X4_MODE_INPUT_TRIGGERED;
516 pm->mode[substream->number] &= ~PORTMAN2X4_MODE_INPUT_TRIGGERED;
517 spin_unlock_irqrestore(&pm->reg_lock, flags);
520 static void snd_portman_midi_output_trigger(struct snd_rawmidi_substream *substream,
523 struct portman *pm = substream->rmidi->private_data;
527 spin_lock_irqsave(&pm->reg_lock, flags);
529 while ((snd_rawmidi_transmit(substream, &byte, 1) == 1))
530 portman_write_midi(pm, substream->number, byte);
532 spin_unlock_irqrestore(&pm->reg_lock, flags);
535 static const struct snd_rawmidi_ops snd_portman_midi_output = {
536 .open = snd_portman_midi_open,
537 .close = snd_portman_midi_close,
538 .trigger = snd_portman_midi_output_trigger,
541 static const struct snd_rawmidi_ops snd_portman_midi_input = {
542 .open = snd_portman_midi_open,
543 .close = snd_portman_midi_close,
544 .trigger = snd_portman_midi_input_trigger,
547 /* Create and initialize the rawmidi component */
548 static int snd_portman_rawmidi_create(struct snd_card *card)
550 struct portman *pm = card->private_data;
551 struct snd_rawmidi *rmidi;
552 struct snd_rawmidi_substream *substream;
555 err = snd_rawmidi_new(card, CARD_NAME, 0,
556 PORTMAN_NUM_OUTPUT_PORTS,
557 PORTMAN_NUM_INPUT_PORTS,
562 rmidi->private_data = pm;
563 strcpy(rmidi->name, CARD_NAME);
564 rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
565 SNDRV_RAWMIDI_INFO_INPUT |
566 SNDRV_RAWMIDI_INFO_DUPLEX;
570 /* register rawmidi ops */
571 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
572 &snd_portman_midi_output);
573 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
574 &snd_portman_midi_input);
576 /* name substreams */
578 list_for_each_entry(substream,
579 &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams,
581 sprintf(substream->name,
582 "Portman2x4 %d", substream->number+1);
585 list_for_each_entry(substream,
586 &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams,
588 pm->midi_input[substream->number] = substream;
589 sprintf(substream->name,
590 "Portman2x4 %d", substream->number+1);
596 /*********************************************************************
598 *********************************************************************/
599 static void snd_portman_interrupt(void *userdata)
601 unsigned char midivalue = 0;
602 struct portman *pm = ((struct snd_card*)userdata)->private_data;
604 spin_lock(&pm->reg_lock);
606 /* While any input data is waiting */
607 while ((portman_read_status(pm) & INT_REQ) == INT_REQ) {
608 /* If data available on channel 0,
609 read it and stuff it into the queue. */
610 if (portman_data_avail(pm, 0)) {
612 midivalue = portman_read_midi(pm, 0);
613 /* put midi into queue... */
614 if (pm->mode[0] & PORTMAN2X4_MODE_INPUT_TRIGGERED)
615 snd_rawmidi_receive(pm->midi_input[0],
619 /* If data available on channel 1,
620 read it and stuff it into the queue. */
621 if (portman_data_avail(pm, 1)) {
623 midivalue = portman_read_midi(pm, 1);
624 /* put midi into queue... */
625 if (pm->mode[1] & PORTMAN2X4_MODE_INPUT_TRIGGERED)
626 snd_rawmidi_receive(pm->midi_input[1],
632 spin_unlock(&pm->reg_lock);
635 static void snd_portman_attach(struct parport *p)
637 struct platform_device *device;
639 device = platform_device_alloc(PLATFORM_DRIVER, device_count);
643 /* Temporary assignment to forward the parport */
644 platform_set_drvdata(device, p);
646 if (platform_device_add(device) < 0) {
647 platform_device_put(device);
651 /* Since we dont get the return value of probe
652 * We need to check if device probing succeeded or not */
653 if (!platform_get_drvdata(device)) {
654 platform_device_unregister(device);
658 /* register device in global table */
659 platform_devices[device_count] = device;
663 static void snd_portman_detach(struct parport *p)
665 /* nothing to do here */
668 static int snd_portman_dev_probe(struct pardevice *pardev)
670 if (strcmp(pardev->name, DRIVER_NAME))
676 static struct parport_driver portman_parport_driver = {
677 .name = "portman2x4",
678 .probe = snd_portman_dev_probe,
679 .match_port = snd_portman_attach,
680 .detach = snd_portman_detach,
684 /*********************************************************************
686 *********************************************************************/
687 static void snd_portman_card_private_free(struct snd_card *card)
689 struct portman *pm = card->private_data;
690 struct pardevice *pardev = pm->pardev;
693 parport_release(pardev);
694 parport_unregister_device(pardev);
700 static int snd_portman_probe(struct platform_device *pdev)
702 struct pardevice *pardev;
705 struct snd_card *card = NULL;
706 struct portman *pm = NULL;
708 struct pardev_cb portman_cb = {
711 .irq_func = snd_portman_interrupt, /* ISR */
712 .flags = PARPORT_DEV_EXCL, /* flags */
715 p = platform_get_drvdata(pdev);
716 platform_set_drvdata(pdev, NULL);
718 if (dev >= SNDRV_CARDS)
723 err = snd_card_new(&pdev->dev, index[dev], id[dev], THIS_MODULE,
726 snd_printd("Cannot create card\n");
729 strcpy(card->driver, DRIVER_NAME);
730 strcpy(card->shortname, CARD_NAME);
731 sprintf(card->longname, "%s at 0x%lx, irq %i",
732 card->shortname, p->base, p->irq);
734 portman_cb.private = card; /* private */
735 pardev = parport_register_dev_model(p, /* port */
736 DRIVER_NAME, /* name */
737 &portman_cb, /* callbacks */
738 pdev->id); /* device number */
739 if (pardev == NULL) {
740 snd_printd("Cannot register pardevice\n");
746 if (parport_claim(pardev)) {
747 snd_printd("Cannot claim parport 0x%lx\n", pardev->port->base);
752 err = portman_create(card, pardev, &pm);
754 snd_printd("Cannot create main component\n");
757 card->private_data = pm;
758 card->private_free = snd_portman_card_private_free;
760 err = portman_probe(p);
766 err = snd_portman_rawmidi_create(card);
768 snd_printd("Creating Rawmidi component failed\n");
773 err = portman_device_init(pm);
777 platform_set_drvdata(pdev, card);
779 /* At this point card will be usable */
780 err = snd_card_register(card);
782 snd_printd("Cannot register card\n");
786 snd_printk(KERN_INFO "Portman 2x4 on 0x%lx\n", p->base);
790 parport_release(pardev);
792 parport_unregister_device(pardev);
798 static int snd_portman_remove(struct platform_device *pdev)
800 struct snd_card *card = platform_get_drvdata(pdev);
809 static struct platform_driver snd_portman_driver = {
810 .probe = snd_portman_probe,
811 .remove = snd_portman_remove,
813 .name = PLATFORM_DRIVER,
817 /*********************************************************************
819 *********************************************************************/
820 static void snd_portman_unregister_all(void)
824 for (i = 0; i < SNDRV_CARDS; ++i) {
825 if (platform_devices[i]) {
826 platform_device_unregister(platform_devices[i]);
827 platform_devices[i] = NULL;
830 platform_driver_unregister(&snd_portman_driver);
831 parport_unregister_driver(&portman_parport_driver);
834 static int __init snd_portman_module_init(void)
838 err = platform_driver_register(&snd_portman_driver);
842 if (parport_register_driver(&portman_parport_driver) != 0) {
843 platform_driver_unregister(&snd_portman_driver);
847 if (device_count == 0) {
848 snd_portman_unregister_all();
855 static void __exit snd_portman_module_exit(void)
857 snd_portman_unregister_all();
860 module_init(snd_portman_module_init);
861 module_exit(snd_portman_module_exit);