1/*
2 *   serial.c
3 *   Copyright (c) by Jaroslav Kysela <perex@perex.cz>,
4 *                    Isaku Yamahata <yamahata@private.email.ne.jp>,
5 *		      George Hansper <ghansper@apana.org.au>,
6 *		      Hannu Savolainen
7 *
8 *   This code is based on the code from ALSA 0.5.9, but heavily rewritten.
9 *
10 *   This program is free software; you can redistribute it and/or modify
11 *   it under the terms of the GNU General Public License as published by
12 *   the Free Software Foundation; either version 2 of the License, or
13 *   (at your option) any later version.
14 *
15 *   This program is distributed in the hope that it will be useful,
16 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
17 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 *   GNU General Public License for more details.
19 *
20 *   You should have received a copy of the GNU General Public License
21 *   along with this program; if not, write to the Free Software
22 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
23 *
24 * Sat Mar 31 17:27:57 PST 2001 tim.mann@compaq.com
25 *      Added support for the Midiator MS-124T and for the MS-124W in
26 *      Single Addressed (S/A) or Multiple Burst (M/B) mode, with
27 *      power derived either parasitically from the serial port or
28 *      from a separate power supply.
29 *
30 *      More documentation can be found in serial-u16550.txt.
31 */
32
33#include <linux/init.h>
34#include <linux/interrupt.h>
35#include <linux/err.h>
36#include <linux/platform_device.h>
37#include <linux/slab.h>
38#include <linux/ioport.h>
39#include <linux/module.h>
40#include <linux/io.h>
41#include <sound/core.h>
42#include <sound/rawmidi.h>
43#include <sound/initval.h>
44
45#include <linux/serial_reg.h>
46#include <linux/jiffies.h>
47
48MODULE_DESCRIPTION("MIDI serial u16550");
49MODULE_LICENSE("GPL");
50MODULE_SUPPORTED_DEVICE("{{ALSA, MIDI serial u16550}}");
51
52#define SNDRV_SERIAL_SOUNDCANVAS 0 /* Roland Soundcanvas; F5 NN selects part */
53#define SNDRV_SERIAL_MS124T 1      /* Midiator MS-124T */
54#define SNDRV_SERIAL_MS124W_SA 2   /* Midiator MS-124W in S/A mode */
55#define SNDRV_SERIAL_MS124W_MB 3   /* Midiator MS-124W in M/B mode */
56#define SNDRV_SERIAL_GENERIC 4     /* Generic Interface */
57#define SNDRV_SERIAL_MAX_ADAPTOR SNDRV_SERIAL_GENERIC
58static char *adaptor_names[] = {
59	"Soundcanvas",
60        "MS-124T",
61	"MS-124W S/A",
62	"MS-124W M/B",
63	"Generic"
64};
65
66#define SNDRV_SERIAL_NORMALBUFF 0 /* Normal blocking buffer operation */
67#define SNDRV_SERIAL_DROPBUFF   1 /* Non-blocking discard operation */
68
69static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
70static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
71static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE; /* Enable this card */
72static long port[SNDRV_CARDS] = SNDRV_DEFAULT_PORT; /* 0x3f8,0x2f8,0x3e8,0x2e8 */
73static int irq[SNDRV_CARDS] = SNDRV_DEFAULT_IRQ; 	/* 3,4,5,7,9,10,11,14,15 */
74static int speed[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 38400}; /* 9600,19200,38400,57600,115200 */
75static int base[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 115200}; /* baud base */
76static int outs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};	 /* 1 to 16 */
77static int ins[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};	/* 1 to 16 */
78static int adaptor[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = SNDRV_SERIAL_SOUNDCANVAS};
79static bool droponfull[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS -1)] = SNDRV_SERIAL_NORMALBUFF };
80
81module_param_array(index, int, NULL, 0444);
82MODULE_PARM_DESC(index, "Index value for Serial MIDI.");
83module_param_array(id, charp, NULL, 0444);
84MODULE_PARM_DESC(id, "ID string for Serial MIDI.");
85module_param_array(enable, bool, NULL, 0444);
86MODULE_PARM_DESC(enable, "Enable UART16550A chip.");
87module_param_array(port, long, NULL, 0444);
88MODULE_PARM_DESC(port, "Port # for UART16550A chip.");
89module_param_array(irq, int, NULL, 0444);
90MODULE_PARM_DESC(irq, "IRQ # for UART16550A chip.");
91module_param_array(speed, int, NULL, 0444);
92MODULE_PARM_DESC(speed, "Speed in bauds.");
93module_param_array(base, int, NULL, 0444);
94MODULE_PARM_DESC(base, "Base for divisor in bauds.");
95module_param_array(outs, int, NULL, 0444);
96MODULE_PARM_DESC(outs, "Number of MIDI outputs.");
97module_param_array(ins, int, NULL, 0444);
98MODULE_PARM_DESC(ins, "Number of MIDI inputs.");
99module_param_array(droponfull, bool, NULL, 0444);
100MODULE_PARM_DESC(droponfull, "Flag to enable drop-on-full buffer mode");
101
102module_param_array(adaptor, int, NULL, 0444);
103MODULE_PARM_DESC(adaptor, "Type of adaptor.");
104
105/*#define SNDRV_SERIAL_MS124W_MB_NOCOMBO 1*/  /* Address outs as 0-3 instead of bitmap */
106
107#define SNDRV_SERIAL_MAX_OUTS	16		/* max 64, min 16 */
108#define SNDRV_SERIAL_MAX_INS	16		/* max 64, min 16 */
109
110#define TX_BUFF_SIZE		(1<<15)		/* Must be 2^n */
111#define TX_BUFF_MASK		(TX_BUFF_SIZE - 1)
112
113#define SERIAL_MODE_NOT_OPENED 		(0)
114#define SERIAL_MODE_INPUT_OPEN		(1 << 0)
115#define SERIAL_MODE_OUTPUT_OPEN		(1 << 1)
116#define SERIAL_MODE_INPUT_TRIGGERED	(1 << 2)
117#define SERIAL_MODE_OUTPUT_TRIGGERED	(1 << 3)
118
119struct snd_uart16550 {
120	struct snd_card *card;
121	struct snd_rawmidi *rmidi;
122	struct snd_rawmidi_substream *midi_output[SNDRV_SERIAL_MAX_OUTS];
123	struct snd_rawmidi_substream *midi_input[SNDRV_SERIAL_MAX_INS];
124
125	int filemode;		/* open status of file */
126
127	spinlock_t open_lock;
128
129	int irq;
130
131	unsigned long base;
132	struct resource *res_base;
133
134	unsigned int speed;
135	unsigned int speed_base;
136	unsigned char divisor;
137
138	unsigned char old_divisor_lsb;
139	unsigned char old_divisor_msb;
140	unsigned char old_line_ctrl_reg;
141
142	/* parameter for using of write loop */
143	short int fifo_limit;	/* used in uart16550 */
144        short int fifo_count;	/* used in uart16550 */
145
146	/* type of adaptor */
147	int adaptor;
148
149	/* inputs */
150	int prev_in;
151	unsigned char rstatus;
152
153	/* outputs */
154	int prev_out;
155	unsigned char prev_status[SNDRV_SERIAL_MAX_OUTS];
156
157	/* write buffer and its writing/reading position */
158	unsigned char tx_buff[TX_BUFF_SIZE];
159	int buff_in_count;
160        int buff_in;
161        int buff_out;
162        int drop_on_full;
163
164	/* wait timer */
165	unsigned int timer_running:1;
166	struct timer_list buffer_timer;
167
168};
169
170static struct platform_device *devices[SNDRV_CARDS];
171
172static inline void snd_uart16550_add_timer(struct snd_uart16550 *uart)
173{
174	if (!uart->timer_running) {
175		/* timer 38600bps * 10bit * 16byte */
176		mod_timer(&uart->buffer_timer, jiffies + (HZ + 255) / 256);
177		uart->timer_running = 1;
178	}
179}
180
181static inline void snd_uart16550_del_timer(struct snd_uart16550 *uart)
182{
183	if (uart->timer_running) {
184		del_timer(&uart->buffer_timer);
185		uart->timer_running = 0;
186	}
187}
188
189/* This macro is only used in snd_uart16550_io_loop */
190static inline void snd_uart16550_buffer_output(struct snd_uart16550 *uart)
191{
192	unsigned short buff_out = uart->buff_out;
193	if (uart->buff_in_count > 0) {
194		outb(uart->tx_buff[buff_out], uart->base + UART_TX);
195		uart->fifo_count++;
196		buff_out++;
197		buff_out &= TX_BUFF_MASK;
198		uart->buff_out = buff_out;
199		uart->buff_in_count--;
200	}
201}
202
203/* This loop should be called with interrupts disabled
204 * We don't want to interrupt this,
205 * as we're already handling an interrupt
206 */
207static void snd_uart16550_io_loop(struct snd_uart16550 * uart)
208{
209	unsigned char c, status;
210	int substream;
211
212	/* recall previous stream */
213	substream = uart->prev_in;
214
215	/* Read Loop */
216	while ((status = inb(uart->base + UART_LSR)) & UART_LSR_DR) {
217		/* while receive data ready */
218		c = inb(uart->base + UART_RX);
219
220		/* keep track of last status byte */
221		if (c & 0x80)
222			uart->rstatus = c;
223
224		/* handle stream switch */
225		if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
226			if (uart->rstatus == 0xf5) {
227				if (c <= SNDRV_SERIAL_MAX_INS && c > 0)
228					substream = c - 1;
229				if (c != 0xf5)
230					/* prevent future bytes from being
231					   interpreted as streams */
232					uart->rstatus = 0;
233			} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN)
234				   && uart->midi_input[substream])
235				snd_rawmidi_receive(uart->midi_input[substream],
236						    &c, 1);
237		} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) &&
238			   uart->midi_input[substream])
239			snd_rawmidi_receive(uart->midi_input[substream], &c, 1);
240
241		if (status & UART_LSR_OE)
242			snd_printk(KERN_WARNING
243				   "%s: Overrun on device at 0x%lx\n",
244			       uart->rmidi->name, uart->base);
245	}
246
247	/* remember the last stream */
248	uart->prev_in = substream;
249
250	/* no need of check SERIAL_MODE_OUTPUT_OPEN because if not,
251	   buffer is never filled. */
252	/* Check write status */
253	if (status & UART_LSR_THRE)
254		uart->fifo_count = 0;
255	if (uart->adaptor == SNDRV_SERIAL_MS124W_SA
256	   || uart->adaptor == SNDRV_SERIAL_GENERIC) {
257		/* Can't use FIFO, must send only when CTS is true */
258		status = inb(uart->base + UART_MSR);
259		while (uart->fifo_count == 0 && (status & UART_MSR_CTS) &&
260		       uart->buff_in_count > 0) {
261		       snd_uart16550_buffer_output(uart);
262		       status = inb(uart->base + UART_MSR);
263		}
264	} else {
265		/* Write loop */
266		while (uart->fifo_count < uart->fifo_limit /* Can we write ? */
267		       && uart->buff_in_count > 0)	/* Do we want to? */
268			snd_uart16550_buffer_output(uart);
269	}
270	if (uart->irq < 0 && uart->buff_in_count > 0)
271		snd_uart16550_add_timer(uart);
272}
273
274/* NOTES ON SERVICING INTERUPTS
275 * ---------------------------
276 * After receiving a interrupt, it is important to indicate to the UART that
277 * this has been done.
278 * For a Rx interrupt, this is done by reading the received byte.
279 * For a Tx interrupt this is done by either:
280 * a) Writing a byte
281 * b) Reading the IIR
282 * It is particularly important to read the IIR if a Tx interrupt is received
283 * when there is no data in tx_buff[], as in this case there no other
284 * indication that the interrupt has been serviced, and it remains outstanding
285 * indefinitely. This has the curious side effect that and no further interrupts
286 * will be generated from this device AT ALL!!.
287 * It is also desirable to clear outstanding interrupts when the device is
288 * opened/closed.
289 *
290 *
291 * Note that some devices need OUT2 to be set before they will generate
292 * interrupts at all. (Possibly tied to an internal pull-up on CTS?)
293 */
294static irqreturn_t snd_uart16550_interrupt(int irq, void *dev_id)
295{
296	struct snd_uart16550 *uart;
297
298	uart = dev_id;
299	spin_lock(&uart->open_lock);
300	if (uart->filemode == SERIAL_MODE_NOT_OPENED) {
301		spin_unlock(&uart->open_lock);
302		return IRQ_NONE;
303	}
304	/* indicate to the UART that the interrupt has been serviced */
305	inb(uart->base + UART_IIR);
306	snd_uart16550_io_loop(uart);
307	spin_unlock(&uart->open_lock);
308	return IRQ_HANDLED;
309}
310
311/* When the polling mode, this function calls snd_uart16550_io_loop. */
312static void snd_uart16550_buffer_timer(unsigned long data)
313{
314	unsigned long flags;
315	struct snd_uart16550 *uart;
316
317	uart = (struct snd_uart16550 *)data;
318	spin_lock_irqsave(&uart->open_lock, flags);
319	snd_uart16550_del_timer(uart);
320	snd_uart16550_io_loop(uart);
321	spin_unlock_irqrestore(&uart->open_lock, flags);
322}
323
324/*
325 *  this method probes, if an uart sits on given port
326 *  return 0 if found
327 *  return negative error if not found
328 */
329static int snd_uart16550_detect(struct snd_uart16550 *uart)
330{
331	unsigned long io_base = uart->base;
332	int ok;
333	unsigned char c;
334
335	/* Do some vague tests for the presence of the uart */
336	if (io_base == 0 || io_base == SNDRV_AUTO_PORT) {
337		return -ENODEV;	/* Not configured */
338	}
339
340	uart->res_base = request_region(io_base, 8, "Serial MIDI");
341	if (uart->res_base == NULL) {
342		snd_printk(KERN_ERR "u16550: can't grab port 0x%lx\n", io_base);
343		return -EBUSY;
344	}
345
346	/* uart detected unless one of the following tests should fail */
347	ok = 1;
348	/* 8 data-bits, 1 stop-bit, parity off, DLAB = 0 */
349	outb(UART_LCR_WLEN8, io_base + UART_LCR); /* Line Control Register */
350	c = inb(io_base + UART_IER);
351	/* The top four bits of the IER should always == 0 */
352	if ((c & 0xf0) != 0)
353		ok = 0;		/* failed */
354
355	outb(0xaa, io_base + UART_SCR);
356	/* Write arbitrary data into the scratch reg */
357	c = inb(io_base + UART_SCR);
358	/* If it comes back, it's OK */
359	if (c != 0xaa)
360		ok = 0;		/* failed */
361
362	outb(0x55, io_base + UART_SCR);
363	/* Write arbitrary data into the scratch reg */
364	c = inb(io_base + UART_SCR);
365	/* If it comes back, it's OK */
366	if (c != 0x55)
367		ok = 0;		/* failed */
368
369	return ok;
370}
371
372static void snd_uart16550_do_open(struct snd_uart16550 * uart)
373{
374	char byte;
375
376	/* Initialize basic variables */
377	uart->buff_in_count = 0;
378	uart->buff_in = 0;
379	uart->buff_out = 0;
380	uart->fifo_limit = 1;
381	uart->fifo_count = 0;
382	uart->timer_running = 0;
383
384	outb(UART_FCR_ENABLE_FIFO	/* Enable FIFO's (if available) */
385	     | UART_FCR_CLEAR_RCVR	/* Clear receiver FIFO */
386	     | UART_FCR_CLEAR_XMIT	/* Clear transmitter FIFO */
387	     | UART_FCR_TRIGGER_4	/* Set FIFO trigger at 4-bytes */
388	/* NOTE: interrupt generated after T=(time)4-bytes
389	 * if less than UART_FCR_TRIGGER bytes received
390	 */
391	     ,uart->base + UART_FCR);	/* FIFO Control Register */
392
393	if ((inb(uart->base + UART_IIR) & 0xf0) == 0xc0)
394		uart->fifo_limit = 16;
395	if (uart->divisor != 0) {
396		uart->old_line_ctrl_reg = inb(uart->base + UART_LCR);
397		outb(UART_LCR_DLAB	/* Divisor latch access bit */
398		     ,uart->base + UART_LCR);	/* Line Control Register */
399		uart->old_divisor_lsb = inb(uart->base + UART_DLL);
400		uart->old_divisor_msb = inb(uart->base + UART_DLM);
401
402		outb(uart->divisor
403		     ,uart->base + UART_DLL);	/* Divisor Latch Low */
404		outb(0
405		     ,uart->base + UART_DLM);	/* Divisor Latch High */
406		/* DLAB is reset to 0 in next outb() */
407	}
408	/* Set serial parameters (parity off, etc) */
409	outb(UART_LCR_WLEN8	/* 8 data-bits */
410	     | 0		/* 1 stop-bit */
411	     | 0		/* parity off */
412	     | 0		/* DLAB = 0 */
413	     ,uart->base + UART_LCR);	/* Line Control Register */
414
415	switch (uart->adaptor) {
416	default:
417		outb(UART_MCR_RTS	/* Set Request-To-Send line active */
418		     | UART_MCR_DTR	/* Set Data-Terminal-Ready line active */
419		     | UART_MCR_OUT2	/* Set OUT2 - not always required, but when
420					 * it is, it is ESSENTIAL for enabling interrupts
421				 */
422		     ,uart->base + UART_MCR);	/* Modem Control Register */
423		break;
424	case SNDRV_SERIAL_MS124W_SA:
425	case SNDRV_SERIAL_MS124W_MB:
426		/* MS-124W can draw power from RTS and DTR if they
427		   are in opposite states. */
428		outb(UART_MCR_RTS | (0&UART_MCR_DTR) | UART_MCR_OUT2,
429		     uart->base + UART_MCR);
430		break;
431	case SNDRV_SERIAL_MS124T:
432		/* MS-124T can draw power from RTS and/or DTR (preferably
433		   both) if they are both asserted. */
434		outb(UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2,
435		     uart->base + UART_MCR);
436		break;
437	}
438
439	if (uart->irq < 0) {
440		byte = (0 & UART_IER_RDI)	/* Disable Receiver data interrupt */
441		    |(0 & UART_IER_THRI)	/* Disable Transmitter holding register empty interrupt */
442		    ;
443	} else if (uart->adaptor == SNDRV_SERIAL_MS124W_SA) {
444		byte = UART_IER_RDI	/* Enable Receiver data interrupt */
445		    | UART_IER_MSI	/* Enable Modem status interrupt */
446		    ;
447	} else if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
448		byte = UART_IER_RDI	/* Enable Receiver data interrupt */
449		    | UART_IER_MSI	/* Enable Modem status interrupt */
450		    | UART_IER_THRI	/* Enable Transmitter holding register empty interrupt */
451		    ;
452	} else {
453		byte = UART_IER_RDI	/* Enable Receiver data interrupt */
454		    | UART_IER_THRI	/* Enable Transmitter holding register empty interrupt */
455		    ;
456	}
457	outb(byte, uart->base + UART_IER);	/* Interrupt enable Register */
458
459	inb(uart->base + UART_LSR);	/* Clear any pre-existing overrun indication */
460	inb(uart->base + UART_IIR);	/* Clear any pre-existing transmit interrupt */
461	inb(uart->base + UART_RX);	/* Clear any pre-existing receive interrupt */
462}
463
464static void snd_uart16550_do_close(struct snd_uart16550 * uart)
465{
466	if (uart->irq < 0)
467		snd_uart16550_del_timer(uart);
468
469	/* NOTE: may need to disable interrupts before de-registering out handler.
470	 * For now, the consequences are harmless.
471	 */
472
473	outb((0 & UART_IER_RDI)		/* Disable Receiver data interrupt */
474	     |(0 & UART_IER_THRI)	/* Disable Transmitter holding register empty interrupt */
475	     ,uart->base + UART_IER);	/* Interrupt enable Register */
476
477	switch (uart->adaptor) {
478	default:
479		outb((0 & UART_MCR_RTS)		/* Deactivate Request-To-Send line  */
480		     |(0 & UART_MCR_DTR)	/* Deactivate Data-Terminal-Ready line */
481		     |(0 & UART_MCR_OUT2)	/* Deactivate OUT2 */
482		     ,uart->base + UART_MCR);	/* Modem Control Register */
483	  break;
484	case SNDRV_SERIAL_MS124W_SA:
485	case SNDRV_SERIAL_MS124W_MB:
486		/* MS-124W can draw power from RTS and DTR if they
487		   are in opposite states; leave it powered. */
488		outb(UART_MCR_RTS | (0&UART_MCR_DTR) | (0&UART_MCR_OUT2),
489		     uart->base + UART_MCR);
490		break;
491	case SNDRV_SERIAL_MS124T:
492		/* MS-124T can draw power from RTS and/or DTR (preferably
493		   both) if they are both asserted; leave it powered. */
494		outb(UART_MCR_RTS | UART_MCR_DTR | (0&UART_MCR_OUT2),
495		     uart->base + UART_MCR);
496		break;
497	}
498
499	inb(uart->base + UART_IIR);	/* Clear any outstanding interrupts */
500
501	/* Restore old divisor */
502	if (uart->divisor != 0) {
503		outb(UART_LCR_DLAB		/* Divisor latch access bit */
504		     ,uart->base + UART_LCR);	/* Line Control Register */
505		outb(uart->old_divisor_lsb
506		     ,uart->base + UART_DLL);	/* Divisor Latch Low */
507		outb(uart->old_divisor_msb
508		     ,uart->base + UART_DLM);	/* Divisor Latch High */
509		/* Restore old LCR (data bits, stop bits, parity, DLAB) */
510		outb(uart->old_line_ctrl_reg
511		     ,uart->base + UART_LCR);	/* Line Control Register */
512	}
513}
514
515static int snd_uart16550_input_open(struct snd_rawmidi_substream *substream)
516{
517	unsigned long flags;
518	struct snd_uart16550 *uart = substream->rmidi->private_data;
519
520	spin_lock_irqsave(&uart->open_lock, flags);
521	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
522		snd_uart16550_do_open(uart);
523	uart->filemode |= SERIAL_MODE_INPUT_OPEN;
524	uart->midi_input[substream->number] = substream;
525	spin_unlock_irqrestore(&uart->open_lock, flags);
526	return 0;
527}
528
529static int snd_uart16550_input_close(struct snd_rawmidi_substream *substream)
530{
531	unsigned long flags;
532	struct snd_uart16550 *uart = substream->rmidi->private_data;
533
534	spin_lock_irqsave(&uart->open_lock, flags);
535	uart->filemode &= ~SERIAL_MODE_INPUT_OPEN;
536	uart->midi_input[substream->number] = NULL;
537	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
538		snd_uart16550_do_close(uart);
539	spin_unlock_irqrestore(&uart->open_lock, flags);
540	return 0;
541}
542
543static void snd_uart16550_input_trigger(struct snd_rawmidi_substream *substream,
544					int up)
545{
546	unsigned long flags;
547	struct snd_uart16550 *uart = substream->rmidi->private_data;
548
549	spin_lock_irqsave(&uart->open_lock, flags);
550	if (up)
551		uart->filemode |= SERIAL_MODE_INPUT_TRIGGERED;
552	else
553		uart->filemode &= ~SERIAL_MODE_INPUT_TRIGGERED;
554	spin_unlock_irqrestore(&uart->open_lock, flags);
555}
556
557static int snd_uart16550_output_open(struct snd_rawmidi_substream *substream)
558{
559	unsigned long flags;
560	struct snd_uart16550 *uart = substream->rmidi->private_data;
561
562	spin_lock_irqsave(&uart->open_lock, flags);
563	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
564		snd_uart16550_do_open(uart);
565	uart->filemode |= SERIAL_MODE_OUTPUT_OPEN;
566	uart->midi_output[substream->number] = substream;
567	spin_unlock_irqrestore(&uart->open_lock, flags);
568	return 0;
569};
570
571static int snd_uart16550_output_close(struct snd_rawmidi_substream *substream)
572{
573	unsigned long flags;
574	struct snd_uart16550 *uart = substream->rmidi->private_data;
575
576	spin_lock_irqsave(&uart->open_lock, flags);
577	uart->filemode &= ~SERIAL_MODE_OUTPUT_OPEN;
578	uart->midi_output[substream->number] = NULL;
579	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
580		snd_uart16550_do_close(uart);
581	spin_unlock_irqrestore(&uart->open_lock, flags);
582	return 0;
583};
584
585static inline int snd_uart16550_buffer_can_write(struct snd_uart16550 *uart,
586						 int Num)
587{
588	if (uart->buff_in_count + Num < TX_BUFF_SIZE)
589		return 1;
590	else
591		return 0;
592}
593
594static inline int snd_uart16550_write_buffer(struct snd_uart16550 *uart,
595					     unsigned char byte)
596{
597	unsigned short buff_in = uart->buff_in;
598	if (uart->buff_in_count < TX_BUFF_SIZE) {
599		uart->tx_buff[buff_in] = byte;
600		buff_in++;
601		buff_in &= TX_BUFF_MASK;
602		uart->buff_in = buff_in;
603		uart->buff_in_count++;
604		if (uart->irq < 0) /* polling mode */
605			snd_uart16550_add_timer(uart);
606		return 1;
607	} else
608		return 0;
609}
610
611static int snd_uart16550_output_byte(struct snd_uart16550 *uart,
612				     struct snd_rawmidi_substream *substream,
613				     unsigned char midi_byte)
614{
615	if (uart->buff_in_count == 0                    /* Buffer empty? */
616	    && ((uart->adaptor != SNDRV_SERIAL_MS124W_SA &&
617	    uart->adaptor != SNDRV_SERIAL_GENERIC) ||
618		(uart->fifo_count == 0                  /* FIFO empty? */
619		 && (inb(uart->base + UART_MSR) & UART_MSR_CTS)))) { /* CTS? */
620
621	        /* Tx Buffer Empty - try to write immediately */
622		if ((inb(uart->base + UART_LSR) & UART_LSR_THRE) != 0) {
623		        /* Transmitter holding register (and Tx FIFO) empty */
624		        uart->fifo_count = 1;
625			outb(midi_byte, uart->base + UART_TX);
626		} else {
627		        if (uart->fifo_count < uart->fifo_limit) {
628			        uart->fifo_count++;
629				outb(midi_byte, uart->base + UART_TX);
630			} else {
631			        /* Cannot write (buffer empty) -
632				 * put char in buffer */
633				snd_uart16550_write_buffer(uart, midi_byte);
634			}
635		}
636	} else {
637		if (!snd_uart16550_write_buffer(uart, midi_byte)) {
638			snd_printk(KERN_WARNING
639				   "%s: Buffer overrun on device at 0x%lx\n",
640				   uart->rmidi->name, uart->base);
641			return 0;
642		}
643	}
644
645	return 1;
646}
647
648static void snd_uart16550_output_write(struct snd_rawmidi_substream *substream)
649{
650	unsigned long flags;
651	unsigned char midi_byte, addr_byte;
652	struct snd_uart16550 *uart = substream->rmidi->private_data;
653	char first;
654	static unsigned long lasttime = 0;
655
656	/* Interrupts are disabled during the updating of the tx_buff,
657	 * since it is 'bad' to have two processes updating the same
658	 * variables (ie buff_in & buff_out)
659	 */
660
661	spin_lock_irqsave(&uart->open_lock, flags);
662
663	if (uart->irq < 0)	/* polling */
664		snd_uart16550_io_loop(uart);
665
666	if (uart->adaptor == SNDRV_SERIAL_MS124W_MB) {
667		while (1) {
668			/* buffer full? */
669			/* in this mode we need two bytes of space */
670			if (uart->buff_in_count > TX_BUFF_SIZE - 2)
671				break;
672			if (snd_rawmidi_transmit(substream, &midi_byte, 1) != 1)
673				break;
674#ifdef SNDRV_SERIAL_MS124W_MB_NOCOMBO
675			/* select exactly one of the four ports */
676			addr_byte = (1 << (substream->number + 4)) | 0x08;
677#else
678			/* select any combination of the four ports */
679			addr_byte = (substream->number << 4) | 0x08;
680			/* ...except none */
681			if (addr_byte == 0x08)
682				addr_byte = 0xf8;
683#endif
684			snd_uart16550_output_byte(uart, substream, addr_byte);
685			/* send midi byte */
686			snd_uart16550_output_byte(uart, substream, midi_byte);
687		}
688	} else {
689		first = 0;
690		while (snd_rawmidi_transmit_peek(substream, &midi_byte, 1) == 1) {
691			/* Also send F5 after 3 seconds with no data
692			 * to handle device disconnect */
693			if (first == 0 &&
694			    (uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS ||
695			     uart->adaptor == SNDRV_SERIAL_GENERIC) &&
696			    (uart->prev_out != substream->number ||
697			     time_after(jiffies, lasttime + 3*HZ))) {
698
699				if (snd_uart16550_buffer_can_write(uart, 3)) {
700					/* Roland Soundcanvas part selection */
701					/* If this substream of the data is
702					 * different previous substream
703					 * in this uart, send the change part
704					 * event
705					 */
706					uart->prev_out = substream->number;
707					/* change part */
708					snd_uart16550_output_byte(uart, substream,
709								  0xf5);
710					/* data */
711					snd_uart16550_output_byte(uart, substream,
712								  uart->prev_out + 1);
713					/* If midi_byte is a data byte,
714					 * send the previous status byte */
715					if (midi_byte < 0x80 &&
716					    uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS)
717						snd_uart16550_output_byte(uart, substream, uart->prev_status[uart->prev_out]);
718				} else if (!uart->drop_on_full)
719					break;
720
721			}
722
723			/* send midi byte */
724			if (!snd_uart16550_output_byte(uart, substream, midi_byte) &&
725			    !uart->drop_on_full )
726				break;
727
728			if (midi_byte >= 0x80 && midi_byte < 0xf0)
729				uart->prev_status[uart->prev_out] = midi_byte;
730			first = 1;
731
732			snd_rawmidi_transmit_ack( substream, 1 );
733		}
734		lasttime = jiffies;
735	}
736	spin_unlock_irqrestore(&uart->open_lock, flags);
737}
738
739static void snd_uart16550_output_trigger(struct snd_rawmidi_substream *substream,
740					 int up)
741{
742	unsigned long flags;
743	struct snd_uart16550 *uart = substream->rmidi->private_data;
744
745	spin_lock_irqsave(&uart->open_lock, flags);
746	if (up)
747		uart->filemode |= SERIAL_MODE_OUTPUT_TRIGGERED;
748	else
749		uart->filemode &= ~SERIAL_MODE_OUTPUT_TRIGGERED;
750	spin_unlock_irqrestore(&uart->open_lock, flags);
751	if (up)
752		snd_uart16550_output_write(substream);
753}
754
755static struct snd_rawmidi_ops snd_uart16550_output =
756{
757	.open =		snd_uart16550_output_open,
758	.close =	snd_uart16550_output_close,
759	.trigger =	snd_uart16550_output_trigger,
760};
761
762static struct snd_rawmidi_ops snd_uart16550_input =
763{
764	.open =		snd_uart16550_input_open,
765	.close =	snd_uart16550_input_close,
766	.trigger =	snd_uart16550_input_trigger,
767};
768
769static int snd_uart16550_free(struct snd_uart16550 *uart)
770{
771	if (uart->irq >= 0)
772		free_irq(uart->irq, uart);
773	release_and_free_resource(uart->res_base);
774	kfree(uart);
775	return 0;
776};
777
778static int snd_uart16550_dev_free(struct snd_device *device)
779{
780	struct snd_uart16550 *uart = device->device_data;
781	return snd_uart16550_free(uart);
782}
783
784static int snd_uart16550_create(struct snd_card *card,
785				unsigned long iobase,
786				int irq,
787				unsigned int speed,
788				unsigned int base,
789				int adaptor,
790				int droponfull,
791				struct snd_uart16550 **ruart)
792{
793	static struct snd_device_ops ops = {
794		.dev_free =	snd_uart16550_dev_free,
795	};
796	struct snd_uart16550 *uart;
797	int err;
798
799
800	if ((uart = kzalloc(sizeof(*uart), GFP_KERNEL)) == NULL)
801		return -ENOMEM;
802	uart->adaptor = adaptor;
803	uart->card = card;
804	spin_lock_init(&uart->open_lock);
805	uart->irq = -1;
806	uart->base = iobase;
807	uart->drop_on_full = droponfull;
808
809	if ((err = snd_uart16550_detect(uart)) <= 0) {
810		printk(KERN_ERR "no UART detected at 0x%lx\n", iobase);
811		snd_uart16550_free(uart);
812		return -ENODEV;
813	}
814
815	if (irq >= 0 && irq != SNDRV_AUTO_IRQ) {
816		if (request_irq(irq, snd_uart16550_interrupt,
817				0, "Serial MIDI", uart)) {
818			snd_printk(KERN_WARNING
819				   "irq %d busy. Using Polling.\n", irq);
820		} else {
821			uart->irq = irq;
822		}
823	}
824	uart->divisor = base / speed;
825	uart->speed = base / (unsigned int)uart->divisor;
826	uart->speed_base = base;
827	uart->prev_out = -1;
828	uart->prev_in = 0;
829	uart->rstatus = 0;
830	memset(uart->prev_status, 0x80, sizeof(unsigned char) * SNDRV_SERIAL_MAX_OUTS);
831	setup_timer(&uart->buffer_timer, snd_uart16550_buffer_timer,
832		    (unsigned long)uart);
833	uart->timer_running = 0;
834
835	/* Register device */
836	if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, uart, &ops)) < 0) {
837		snd_uart16550_free(uart);
838		return err;
839	}
840
841	switch (uart->adaptor) {
842	case SNDRV_SERIAL_MS124W_SA:
843	case SNDRV_SERIAL_MS124W_MB:
844		/* MS-124W can draw power from RTS and DTR if they
845		   are in opposite states. */
846		outb(UART_MCR_RTS | (0&UART_MCR_DTR), uart->base + UART_MCR);
847		break;
848	case SNDRV_SERIAL_MS124T:
849		/* MS-124T can draw power from RTS and/or DTR (preferably
850		   both) if they are asserted. */
851		outb(UART_MCR_RTS | UART_MCR_DTR, uart->base + UART_MCR);
852		break;
853	default:
854		break;
855	}
856
857	if (ruart)
858		*ruart = uart;
859
860	return 0;
861}
862
863static void snd_uart16550_substreams(struct snd_rawmidi_str *stream)
864{
865	struct snd_rawmidi_substream *substream;
866
867	list_for_each_entry(substream, &stream->substreams, list) {
868		sprintf(substream->name, "Serial MIDI %d", substream->number + 1);
869	}
870}
871
872static int snd_uart16550_rmidi(struct snd_uart16550 *uart, int device,
873			       int outs, int ins,
874			       struct snd_rawmidi **rmidi)
875{
876	struct snd_rawmidi *rrawmidi;
877	int err;
878
879	err = snd_rawmidi_new(uart->card, "UART Serial MIDI", device,
880			      outs, ins, &rrawmidi);
881	if (err < 0)
882		return err;
883	snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_INPUT,
884			    &snd_uart16550_input);
885	snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
886			    &snd_uart16550_output);
887	strcpy(rrawmidi->name, "Serial MIDI");
888	snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
889	snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
890	rrawmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
891			       SNDRV_RAWMIDI_INFO_INPUT |
892			       SNDRV_RAWMIDI_INFO_DUPLEX;
893	rrawmidi->private_data = uart;
894	if (rmidi)
895		*rmidi = rrawmidi;
896	return 0;
897}
898
899static int snd_serial_probe(struct platform_device *devptr)
900{
901	struct snd_card *card;
902	struct snd_uart16550 *uart;
903	int err;
904	int dev = devptr->id;
905
906	switch (adaptor[dev]) {
907	case SNDRV_SERIAL_SOUNDCANVAS:
908		ins[dev] = 1;
909		break;
910	case SNDRV_SERIAL_MS124T:
911	case SNDRV_SERIAL_MS124W_SA:
912		outs[dev] = 1;
913		ins[dev] = 1;
914		break;
915	case SNDRV_SERIAL_MS124W_MB:
916		outs[dev] = 16;
917		ins[dev] = 1;
918		break;
919	case SNDRV_SERIAL_GENERIC:
920		break;
921	default:
922		snd_printk(KERN_ERR
923			   "Adaptor type is out of range 0-%d (%d)\n",
924			   SNDRV_SERIAL_MAX_ADAPTOR, adaptor[dev]);
925		return -ENODEV;
926	}
927
928	if (outs[dev] < 1 || outs[dev] > SNDRV_SERIAL_MAX_OUTS) {
929		snd_printk(KERN_ERR
930			   "Count of outputs is out of range 1-%d (%d)\n",
931			   SNDRV_SERIAL_MAX_OUTS, outs[dev]);
932		return -ENODEV;
933	}
934
935	if (ins[dev] < 1 || ins[dev] > SNDRV_SERIAL_MAX_INS) {
936		snd_printk(KERN_ERR
937			   "Count of inputs is out of range 1-%d (%d)\n",
938			   SNDRV_SERIAL_MAX_INS, ins[dev]);
939		return -ENODEV;
940	}
941
942	err  = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
943			    0, &card);
944	if (err < 0)
945		return err;
946
947	strcpy(card->driver, "Serial");
948	strcpy(card->shortname, "Serial MIDI (UART16550A)");
949
950	if ((err = snd_uart16550_create(card,
951					port[dev],
952					irq[dev],
953					speed[dev],
954					base[dev],
955					adaptor[dev],
956					droponfull[dev],
957					&uart)) < 0)
958		goto _err;
959
960	err = snd_uart16550_rmidi(uart, 0, outs[dev], ins[dev], &uart->rmidi);
961	if (err < 0)
962		goto _err;
963
964	sprintf(card->longname, "%s [%s] at %#lx, irq %d",
965		card->shortname,
966		adaptor_names[uart->adaptor],
967		uart->base,
968		uart->irq);
969
970	if ((err = snd_card_register(card)) < 0)
971		goto _err;
972
973	platform_set_drvdata(devptr, card);
974	return 0;
975
976 _err:
977	snd_card_free(card);
978	return err;
979}
980
981static int snd_serial_remove(struct platform_device *devptr)
982{
983	snd_card_free(platform_get_drvdata(devptr));
984	return 0;
985}
986
987#define SND_SERIAL_DRIVER	"snd_serial_u16550"
988
989static struct platform_driver snd_serial_driver = {
990	.probe		= snd_serial_probe,
991	.remove		=  snd_serial_remove,
992	.driver		= {
993		.name	= SND_SERIAL_DRIVER,
994	},
995};
996
997static void snd_serial_unregister_all(void)
998{
999	int i;
1000
1001	for (i = 0; i < ARRAY_SIZE(devices); ++i)
1002		platform_device_unregister(devices[i]);
1003	platform_driver_unregister(&snd_serial_driver);
1004}
1005
1006static int __init alsa_card_serial_init(void)
1007{
1008	int i, cards, err;
1009
1010	if ((err = platform_driver_register(&snd_serial_driver)) < 0)
1011		return err;
1012
1013	cards = 0;
1014	for (i = 0; i < SNDRV_CARDS; i++) {
1015		struct platform_device *device;
1016		if (! enable[i])
1017			continue;
1018		device = platform_device_register_simple(SND_SERIAL_DRIVER,
1019							 i, NULL, 0);
1020		if (IS_ERR(device))
1021			continue;
1022		if (!platform_get_drvdata(device)) {
1023			platform_device_unregister(device);
1024			continue;
1025		}
1026		devices[i] = device;
1027		cards++;
1028	}
1029	if (! cards) {
1030#ifdef MODULE
1031		printk(KERN_ERR "serial midi soundcard not found or device busy\n");
1032#endif
1033		snd_serial_unregister_all();
1034		return -ENODEV;
1035	}
1036	return 0;
1037}
1038
1039static void __exit alsa_card_serial_exit(void)
1040{
1041	snd_serial_unregister_all();
1042}
1043
1044module_init(alsa_card_serial_init)
1045module_exit(alsa_card_serial_exit)
1046