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source: GPL/trunk/alsa-kernel/drivers/serial-u16550.c@ 695

Last change on this file since 695 was 695, checked in by David Azarewicz, 4 years ago
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File size: 30.0 KB

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1	// SPDX-License-Identifier: GPL-2.0-or-later
2	/*
3	* serial.c
4	* Copyright (c) by Jaroslav Kysela <perex@perex.cz>,
5	* Isaku Yamahata <yamahata@private.email.ne.jp>,
6	* George Hansper <ghansper@apana.org.au>,
7	* Hannu Savolainen
8	*
9	* This code is based on the code from ALSA 0.5.9, but heavily rewritten.
10	*
11	* Sat Mar 31 17:27:57 PST 2001 tim.mann@compaq.com
12	* Added support for the Midiator MS-124T and for the MS-124W in
13	* Single Addressed (S/A) or Multiple Burst (M/B) mode, with
14	* power derived either parasitically from the serial port or
15	* from a separate power supply.
16	*
17	* More documentation can be found in serial-u16550.txt.
18	*/
19
20	#include <linux/init.h>
21	#include <linux/interrupt.h>
22	#include <linux/err.h>
23	#include <linux/platform_device.h>
24	#include <linux/slab.h>
25	#include <linux/ioport.h>
26	#include <linux/module.h>
27	#include <linux/io.h>
28	#include <sound/core.h>
29	#include <sound/rawmidi.h>
30	#include <sound/initval.h>
31
32	#include <linux/serial_reg.h>
33	#include <linux/jiffies.h>
34
35	MODULE_DESCRIPTION("MIDI serial u16550");
36	MODULE_LICENSE("GPL");
37
38	#define SNDRV_SERIAL_SOUNDCANVAS 0 /* Roland Soundcanvas; F5 NN selects part */
39	#define SNDRV_SERIAL_MS124T 1 /* Midiator MS-124T */
40	#define SNDRV_SERIAL_MS124W_SA 2 /* Midiator MS-124W in S/A mode */
41	#define SNDRV_SERIAL_MS124W_MB 3 /* Midiator MS-124W in M/B mode */
42	#define SNDRV_SERIAL_GENERIC 4 /* Generic Interface */
43	#define SNDRV_SERIAL_MAX_ADAPTOR SNDRV_SERIAL_GENERIC
44	static const char * const adaptor_names[] = {
45	"Soundcanvas",
46	"MS-124T",
47	"MS-124W S/A",
48	"MS-124W M/B",
49	"Generic"
50	};
51
52	#define SNDRV_SERIAL_NORMALBUFF 0 /* Normal blocking buffer operation */
53	#define SNDRV_SERIAL_DROPBUFF 1 /* Non-blocking discard operation */
54
55	static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
56	static char id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; / ID for this card */
57	static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE; /* Enable this card */
58	static long port[SNDRV_CARDS] = SNDRV_DEFAULT_PORT; /* 0x3f8,0x2f8,0x3e8,0x2e8 */
59	static int irq[SNDRV_CARDS] = SNDRV_DEFAULT_IRQ; /* 3,4,5,7,9,10,11,14,15 */
60	static int speed[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 38400}; /* 9600,19200,38400,57600,115200 */
61	static int base[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 115200}; /* baud base */
62	static int outs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1}; /* 1 to 16 */
63	static int ins[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1}; /* 1 to 16 */
64	static int adaptor[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = SNDRV_SERIAL_SOUNDCANVAS};
65	static bool droponfull[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS -1)] = SNDRV_SERIAL_NORMALBUFF };
66
67	module_param_array(index, int, NULL, 0444);
68	MODULE_PARM_DESC(index, "Index value for Serial MIDI.");
69	module_param_array(id, charp, NULL, 0444);
70	MODULE_PARM_DESC(id, "ID string for Serial MIDI.");
71	module_param_array(enable, bool, NULL, 0444);
72	MODULE_PARM_DESC(enable, "Enable UART16550A chip.");
73	module_param_hw_array(port, long, ioport, NULL, 0444);
74	MODULE_PARM_DESC(port, "Port # for UART16550A chip.");
75	module_param_hw_array(irq, int, irq, NULL, 0444);
76	MODULE_PARM_DESC(irq, "IRQ # for UART16550A chip.");
77	module_param_array(speed, int, NULL, 0444);
78	MODULE_PARM_DESC(speed, "Speed in bauds.");
79	module_param_array(base, int, NULL, 0444);
80	MODULE_PARM_DESC(base, "Base for divisor in bauds.");
81	module_param_array(outs, int, NULL, 0444);
82	MODULE_PARM_DESC(outs, "Number of MIDI outputs.");
83	module_param_array(ins, int, NULL, 0444);
84	MODULE_PARM_DESC(ins, "Number of MIDI inputs.");
85	module_param_array(droponfull, bool, NULL, 0444);
86	MODULE_PARM_DESC(droponfull, "Flag to enable drop-on-full buffer mode");
87
88	module_param_array(adaptor, int, NULL, 0444);
89	MODULE_PARM_DESC(adaptor, "Type of adaptor.");
90
91	/#define SNDRV_SERIAL_MS124W_MB_NOCOMBO 1/ /* Address outs as 0-3 instead of bitmap */
92
93	#define SNDRV_SERIAL_MAX_OUTS 16 /* max 64, min 16 */
94	#define SNDRV_SERIAL_MAX_INS 16 /* max 64, min 16 */
95
96	#define TX_BUFF_SIZE (1<<15) /* Must be 2^n */
97	#define TX_BUFF_MASK (TX_BUFF_SIZE - 1)
98
99	#define SERIAL_MODE_NOT_OPENED (0)
100	#define SERIAL_MODE_INPUT_OPEN (1 << 0)
101	#define SERIAL_MODE_OUTPUT_OPEN (1 << 1)
102	#define SERIAL_MODE_INPUT_TRIGGERED (1 << 2)
103	#define SERIAL_MODE_OUTPUT_TRIGGERED (1 << 3)
104
105	struct snd_uart16550 {
106	struct snd_card *card;
107	struct snd_rawmidi *rmidi;
108	struct snd_rawmidi_substream *midi_output[SNDRV_SERIAL_MAX_OUTS];
109	struct snd_rawmidi_substream *midi_input[SNDRV_SERIAL_MAX_INS];
110
111	int filemode; /* open status of file */
112
113	spinlock_t open_lock;
114
115	int irq;
116
117	unsigned long base;
118	struct resource *res_base;
119
120	unsigned int speed;
121	unsigned int speed_base;
122	unsigned char divisor;
123
124	unsigned char old_divisor_lsb;
125	unsigned char old_divisor_msb;
126	unsigned char old_line_ctrl_reg;
127
128	/* parameter for using of write loop */
129	short int fifo_limit; /* used in uart16550 */
130	short int fifo_count; /* used in uart16550 */
131
132	/* type of adaptor */
133	int adaptor;
134
135	/* inputs */
136	int prev_in;
137	unsigned char rstatus;
138
139	/* outputs */
140	int prev_out;
141	unsigned char prev_status[SNDRV_SERIAL_MAX_OUTS];
142
143	/* write buffer and its writing/reading position */
144	unsigned char tx_buff[TX_BUFF_SIZE];
145	int buff_in_count;
146	int buff_in;
147	int buff_out;
148	int drop_on_full;
149
150	/* wait timer */
151	unsigned int timer_running:1;
152	struct timer_list buffer_timer;
153
154	};
155
156	static struct platform_device *devices[SNDRV_CARDS];
157
158	static inline void snd_uart16550_add_timer(struct snd_uart16550 *uart)
159	{
160	if (!uart->timer_running) {
161	/* timer 38600bps * 10bit * 16byte */
162	mod_timer(&uart->buffer_timer, jiffies + (HZ + 255) / 256);
163	uart->timer_running = 1;
164	}
165	}
166
167	static inline void snd_uart16550_del_timer(struct snd_uart16550 *uart)
168	{
169	if (uart->timer_running) {
170	del_timer(&uart->buffer_timer);
171	uart->timer_running = 0;
172	}
173	}
174
175	/* This macro is only used in snd_uart16550_io_loop */
176	static inline void snd_uart16550_buffer_output(struct snd_uart16550 *uart)
177	{
178	unsigned short buff_out = uart->buff_out;
179	if (uart->buff_in_count > 0) {
180	outb(uart->tx_buff[buff_out], uart->base + UART_TX);
181	uart->fifo_count++;
182	buff_out++;
183	buff_out &= TX_BUFF_MASK;
184	uart->buff_out = buff_out;
185	uart->buff_in_count--;
186	}
187	}
188
189	/* This loop should be called with interrupts disabled
190	* We don't want to interrupt this,
191	* as we're already handling an interrupt
192	*/
193	static void snd_uart16550_io_loop(struct snd_uart16550 * uart)
194	{
195	unsigned char c, status;
196	int substream;
197
198	/* recall previous stream */
199	substream = uart->prev_in;
200
201	/* Read Loop */
202	while ((status = inb(uart->base + UART_LSR)) & UART_LSR_DR) {
203	/* while receive data ready */
204	c = inb(uart->base + UART_RX);
205
206	/* keep track of last status byte */
207	if (c & 0x80)
208	uart->rstatus = c;
209
210	/* handle stream switch */
211	if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
212	if (uart->rstatus == 0xf5) {
213	if (c <= SNDRV_SERIAL_MAX_INS && c > 0)
214	substream = c - 1;
215	if (c != 0xf5)
216	/* prevent future bytes from being
217	interpreted as streams */
218	uart->rstatus = 0;
219	} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN)
220	&& uart->midi_input[substream])
221	snd_rawmidi_receive(uart->midi_input[substream],
222	&c, 1);
223	} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) &&
224	uart->midi_input[substream])
225	snd_rawmidi_receive(uart->midi_input[substream], &c, 1);
226
227	if (status & UART_LSR_OE)
228	snd_printk(KERN_WARNING
229	"%s: Overrun on device at 0x%lx\n",
230	uart->rmidi->name, uart->base);
231	}
232
233	/* remember the last stream */
234	uart->prev_in = substream;
235
236	/* no need of check SERIAL_MODE_OUTPUT_OPEN because if not,
237	buffer is never filled. */
238	/* Check write status */
239	if (status & UART_LSR_THRE)
240	uart->fifo_count = 0;
241	if (uart->adaptor == SNDRV_SERIAL_MS124W_SA
242	\|\| uart->adaptor == SNDRV_SERIAL_GENERIC) {
243	/* Can't use FIFO, must send only when CTS is true */
244	status = inb(uart->base + UART_MSR);
245	while (uart->fifo_count == 0 && (status & UART_MSR_CTS) &&
246	uart->buff_in_count > 0) {
247	snd_uart16550_buffer_output(uart);
248	status = inb(uart->base + UART_MSR);
249	}
250	} else {
251	/* Write loop */
252	while (uart->fifo_count < uart->fifo_limit /* Can we write ? */
253	&& uart->buff_in_count > 0) /* Do we want to? */
254	snd_uart16550_buffer_output(uart);
255	}
256	if (uart->irq < 0 && uart->buff_in_count > 0)
257	snd_uart16550_add_timer(uart);
258	}
259
260	/* NOTES ON SERVICING INTERUPTS
261	* ---------------------------
262	* After receiving a interrupt, it is important to indicate to the UART that
263	* this has been done.
264	* For a Rx interrupt, this is done by reading the received byte.
265	* For a Tx interrupt this is done by either:
266	* a) Writing a byte
267	* b) Reading the IIR
268	* It is particularly important to read the IIR if a Tx interrupt is received
269	* when there is no data in tx_buff[], as in this case there no other
270	* indication that the interrupt has been serviced, and it remains outstanding
271	* indefinitely. This has the curious side effect that and no further interrupts
272	* will be generated from this device AT ALL!!.
273	* It is also desirable to clear outstanding interrupts when the device is
274	* opened/closed.
275	*
276	*
277	* Note that some devices need OUT2 to be set before they will generate
278	* interrupts at all. (Possibly tied to an internal pull-up on CTS?)
279	*/
280	static irqreturn_t snd_uart16550_interrupt(int irq, void *dev_id)
281	{
282	struct snd_uart16550 *uart;
283
284	uart = dev_id;
285	spin_lock(&uart->open_lock);
286	if (uart->filemode == SERIAL_MODE_NOT_OPENED) {
287	spin_unlock(&uart->open_lock);
288	return IRQ_NONE;
289	}
290	/* indicate to the UART that the interrupt has been serviced */
291	inb(uart->base + UART_IIR);
292	snd_uart16550_io_loop(uart);
293	spin_unlock(&uart->open_lock);
294	return IRQ_HANDLED;
295	}
296
297	/* When the polling mode, this function calls snd_uart16550_io_loop. */
298	static void snd_uart16550_buffer_timer(struct timer_list *t)
299	{
300	unsigned long flags;
301	struct snd_uart16550 *uart;
302
303	uart = from_timer(uart, t, buffer_timer);
304	spin_lock_irqsave(&uart->open_lock, flags);
305	snd_uart16550_del_timer(uart);
306	snd_uart16550_io_loop(uart);
307	spin_unlock_irqrestore(&uart->open_lock, flags);
308	}
309
310	/*
311	* this method probes, if an uart sits on given port
312	* return 0 if found
313	* return negative error if not found
314	*/
315	static int snd_uart16550_detect(struct snd_uart16550 *uart)
316	{
317	unsigned long io_base = uart->base;
318	int ok;
319	unsigned char c;
320
321	/* Do some vague tests for the presence of the uart */
322	if (io_base == 0 \|\| io_base == SNDRV_AUTO_PORT) {
323	return -ENODEV; /* Not configured */
324	}
325
326	uart->res_base = request_region(io_base, 8, "Serial MIDI");
327	if (uart->res_base == NULL) {
328	snd_printk(KERN_ERR "u16550: can't grab port 0x%lx\n", io_base);
329	return -EBUSY;
330	}
331
332	/* uart detected unless one of the following tests should fail */
333	ok = 1;
334	/* 8 data-bits, 1 stop-bit, parity off, DLAB = 0 */
335	outb(UART_LCR_WLEN8, io_base + UART_LCR); /* Line Control Register */
336	c = inb(io_base + UART_IER);
337	/* The top four bits of the IER should always == 0 */
338	if ((c & 0xf0) != 0)
339	ok = 0; /* failed */
340
341	outb(0xaa, io_base + UART_SCR);
342	/* Write arbitrary data into the scratch reg */
343	c = inb(io_base + UART_SCR);
344	/* If it comes back, it's OK */
345	if (c != 0xaa)
346	ok = 0; /* failed */
347
348	outb(0x55, io_base + UART_SCR);
349	/* Write arbitrary data into the scratch reg */
350	c = inb(io_base + UART_SCR);
351	/* If it comes back, it's OK */
352	if (c != 0x55)
353	ok = 0; /* failed */
354
355	return ok;
356	}
357
358	static void snd_uart16550_do_open(struct snd_uart16550 * uart)
359	{
360	char byte;
361
362	/* Initialize basic variables */
363	uart->buff_in_count = 0;
364	uart->buff_in = 0;
365	uart->buff_out = 0;
366	uart->fifo_limit = 1;
367	uart->fifo_count = 0;
368	uart->timer_running = 0;
369
370	outb(UART_FCR_ENABLE_FIFO /* Enable FIFO's (if available) */
371	\| UART_FCR_CLEAR_RCVR /* Clear receiver FIFO */
372	\| UART_FCR_CLEAR_XMIT /* Clear transmitter FIFO */
373	\| UART_FCR_TRIGGER_4 /* Set FIFO trigger at 4-bytes */
374	/* NOTE: interrupt generated after T=(time)4-bytes
375	* if less than UART_FCR_TRIGGER bytes received
376	*/
377	,uart->base + UART_FCR); /* FIFO Control Register */
378
379	if ((inb(uart->base + UART_IIR) & 0xf0) == 0xc0)
380	uart->fifo_limit = 16;
381	if (uart->divisor != 0) {
382	uart->old_line_ctrl_reg = inb(uart->base + UART_LCR);
383	outb(UART_LCR_DLAB /* Divisor latch access bit */
384	,uart->base + UART_LCR); /* Line Control Register */
385	uart->old_divisor_lsb = inb(uart->base + UART_DLL);
386	uart->old_divisor_msb = inb(uart->base + UART_DLM);
387
388	outb(uart->divisor
389	,uart->base + UART_DLL); /* Divisor Latch Low */
390	outb(0
391	,uart->base + UART_DLM); /* Divisor Latch High */
392	/* DLAB is reset to 0 in next outb() */
393	}
394	/* Set serial parameters (parity off, etc) */
395	outb(UART_LCR_WLEN8 /* 8 data-bits */
396	\| 0 /* 1 stop-bit */
397	\| 0 /* parity off */
398	\| 0 /* DLAB = 0 */
399	,uart->base + UART_LCR); /* Line Control Register */
400
401	switch (uart->adaptor) {
402	default:
403	outb(UART_MCR_RTS /* Set Request-To-Send line active */
404	\| UART_MCR_DTR /* Set Data-Terminal-Ready line active */
405	\| UART_MCR_OUT2 /* Set OUT2 - not always required, but when
406	* it is, it is ESSENTIAL for enabling interrupts
407	*/
408	,uart->base + UART_MCR); /* Modem Control Register */
409	break;
410	case SNDRV_SERIAL_MS124W_SA:
411	case SNDRV_SERIAL_MS124W_MB:
412	/* MS-124W can draw power from RTS and DTR if they
413	are in opposite states. */
414	outb(UART_MCR_RTS \| (0&UART_MCR_DTR) \| UART_MCR_OUT2,
415	uart->base + UART_MCR);
416	break;
417	case SNDRV_SERIAL_MS124T:
418	/* MS-124T can draw power from RTS and/or DTR (preferably
419	both) if they are both asserted. */
420	outb(UART_MCR_RTS \| UART_MCR_DTR \| UART_MCR_OUT2,
421	uart->base + UART_MCR);
422	break;
423	}
424
425	if (uart->irq < 0) {
426	byte = (0 & UART_IER_RDI) /* Disable Receiver data interrupt */
427	\|(0 & UART_IER_THRI) /* Disable Transmitter holding register empty interrupt */
428	;
429	} else if (uart->adaptor == SNDRV_SERIAL_MS124W_SA) {
430	byte = UART_IER_RDI /* Enable Receiver data interrupt */
431	\| UART_IER_MSI /* Enable Modem status interrupt */
432	;
433	} else if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
434	byte = UART_IER_RDI /* Enable Receiver data interrupt */
435	\| UART_IER_MSI /* Enable Modem status interrupt */
436	\| UART_IER_THRI /* Enable Transmitter holding register empty interrupt */
437	;
438	} else {
439	byte = UART_IER_RDI /* Enable Receiver data interrupt */
440	\| UART_IER_THRI /* Enable Transmitter holding register empty interrupt */
441	;
442	}
443	outb(byte, uart->base + UART_IER); /* Interrupt enable Register */
444
445	inb(uart->base + UART_LSR); /* Clear any pre-existing overrun indication */
446	inb(uart->base + UART_IIR); /* Clear any pre-existing transmit interrupt */
447	inb(uart->base + UART_RX); /* Clear any pre-existing receive interrupt */
448	}
449
450	static void snd_uart16550_do_close(struct snd_uart16550 * uart)
451	{
452	if (uart->irq < 0)
453	snd_uart16550_del_timer(uart);
454
455	/* NOTE: may need to disable interrupts before de-registering out handler.
456	* For now, the consequences are harmless.
457	*/
458
459	outb((0 & UART_IER_RDI) /* Disable Receiver data interrupt */
460	\|(0 & UART_IER_THRI) /* Disable Transmitter holding register empty interrupt */
461	,uart->base + UART_IER); /* Interrupt enable Register */
462
463	switch (uart->adaptor) {
464	default:
465	outb((0 & UART_MCR_RTS) /* Deactivate Request-To-Send line */
466	\|(0 & UART_MCR_DTR) /* Deactivate Data-Terminal-Ready line */
467	\|(0 & UART_MCR_OUT2) /* Deactivate OUT2 */
468	,uart->base + UART_MCR); /* Modem Control Register */
469	break;
470	case SNDRV_SERIAL_MS124W_SA:
471	case SNDRV_SERIAL_MS124W_MB:
472	/* MS-124W can draw power from RTS and DTR if they
473	are in opposite states; leave it powered. */
474	outb(UART_MCR_RTS \| (0&UART_MCR_DTR) \| (0&UART_MCR_OUT2),
475	uart->base + UART_MCR);
476	break;
477	case SNDRV_SERIAL_MS124T:
478	/* MS-124T can draw power from RTS and/or DTR (preferably
479	both) if they are both asserted; leave it powered. */
480	outb(UART_MCR_RTS \| UART_MCR_DTR \| (0&UART_MCR_OUT2),
481	uart->base + UART_MCR);
482	break;
483	}
484
485	inb(uart->base + UART_IIR); /* Clear any outstanding interrupts */
486
487	/* Restore old divisor */
488	if (uart->divisor != 0) {
489	outb(UART_LCR_DLAB /* Divisor latch access bit */
490	,uart->base + UART_LCR); /* Line Control Register */
491	outb(uart->old_divisor_lsb
492	,uart->base + UART_DLL); /* Divisor Latch Low */
493	outb(uart->old_divisor_msb
494	,uart->base + UART_DLM); /* Divisor Latch High */
495	/* Restore old LCR (data bits, stop bits, parity, DLAB) */
496	outb(uart->old_line_ctrl_reg
497	,uart->base + UART_LCR); /* Line Control Register */
498	}
499	}
500
501	static int snd_uart16550_input_open(struct snd_rawmidi_substream *substream)
502	{
503	unsigned long flags;
504	struct snd_uart16550 *uart = substream->rmidi->private_data;
505
506	spin_lock_irqsave(&uart->open_lock, flags);
507	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
508	snd_uart16550_do_open(uart);
509	uart->filemode \|= SERIAL_MODE_INPUT_OPEN;
510	uart->midi_input[substream->number] = substream;
511	spin_unlock_irqrestore(&uart->open_lock, flags);
512	return 0;
513	}
514
515	static int snd_uart16550_input_close(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	uart->filemode &= ~SERIAL_MODE_INPUT_OPEN;
522	uart->midi_input[substream->number] = NULL;
523	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
524	snd_uart16550_do_close(uart);
525	spin_unlock_irqrestore(&uart->open_lock, flags);
526	return 0;
527	}
528
529	static void snd_uart16550_input_trigger(struct snd_rawmidi_substream *substream,
530	int up)
531	{
532	unsigned long flags;
533	struct snd_uart16550 *uart = substream->rmidi->private_data;
534
535	spin_lock_irqsave(&uart->open_lock, flags);
536	if (up)
537	uart->filemode \|= SERIAL_MODE_INPUT_TRIGGERED;
538	else
539	uart->filemode &= ~SERIAL_MODE_INPUT_TRIGGERED;
540	spin_unlock_irqrestore(&uart->open_lock, flags);
541	}
542
543	static int snd_uart16550_output_open(struct snd_rawmidi_substream *substream)
544	{
545	unsigned long flags;
546	struct snd_uart16550 *uart = substream->rmidi->private_data;
547
548	spin_lock_irqsave(&uart->open_lock, flags);
549	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
550	snd_uart16550_do_open(uart);
551	uart->filemode \|= SERIAL_MODE_OUTPUT_OPEN;
552	uart->midi_output[substream->number] = substream;
553	spin_unlock_irqrestore(&uart->open_lock, flags);
554	return 0;
555	};
556
557	static int snd_uart16550_output_close(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	uart->filemode &= ~SERIAL_MODE_OUTPUT_OPEN;
564	uart->midi_output[substream->number] = NULL;
565	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
566	snd_uart16550_do_close(uart);
567	spin_unlock_irqrestore(&uart->open_lock, flags);
568	return 0;
569	};
570
571	static inline int snd_uart16550_buffer_can_write(struct snd_uart16550 *uart,
572	int Num)
573	{
574	if (uart->buff_in_count + Num < TX_BUFF_SIZE)
575	return 1;
576	else
577	return 0;
578	}
579
580	static inline int snd_uart16550_write_buffer(struct snd_uart16550 *uart,
581	unsigned char byte)
582	{
583	unsigned short buff_in = uart->buff_in;
584	if (uart->buff_in_count < TX_BUFF_SIZE) {
585	uart->tx_buff[buff_in] = byte;
586	buff_in++;
587	buff_in &= TX_BUFF_MASK;
588	uart->buff_in = buff_in;
589	uart->buff_in_count++;
590	if (uart->irq < 0) /* polling mode */
591	snd_uart16550_add_timer(uart);
592	return 1;
593	} else
594	return 0;
595	}
596
597	static int snd_uart16550_output_byte(struct snd_uart16550 *uart,
598	struct snd_rawmidi_substream *substream,
599	unsigned char midi_byte)
600	{
601	if (uart->buff_in_count == 0 /* Buffer empty? */
602	&& ((uart->adaptor != SNDRV_SERIAL_MS124W_SA &&
603	uart->adaptor != SNDRV_SERIAL_GENERIC) \|\|
604	(uart->fifo_count == 0 /* FIFO empty? */
605	&& (inb(uart->base + UART_MSR) & UART_MSR_CTS)))) { /* CTS? */
606
607	/* Tx Buffer Empty - try to write immediately */
608	if ((inb(uart->base + UART_LSR) & UART_LSR_THRE) != 0) {
609	/* Transmitter holding register (and Tx FIFO) empty */
610	uart->fifo_count = 1;
611	outb(midi_byte, uart->base + UART_TX);
612	} else {
613	if (uart->fifo_count < uart->fifo_limit) {
614	uart->fifo_count++;
615	outb(midi_byte, uart->base + UART_TX);
616	} else {
617	/* Cannot write (buffer empty) -
618	* put char in buffer */
619	snd_uart16550_write_buffer(uart, midi_byte);
620	}
621	}
622	} else {
623	if (!snd_uart16550_write_buffer(uart, midi_byte)) {
624	snd_printk(KERN_WARNING
625	"%s: Buffer overrun on device at 0x%lx\n",
626	uart->rmidi->name, uart->base);
627	return 0;
628	}
629	}
630
631	return 1;
632	}
633
634	static void snd_uart16550_output_write(struct snd_rawmidi_substream *substream)
635	{
636	unsigned long flags;
637	unsigned char midi_byte, addr_byte;
638	struct snd_uart16550 *uart = substream->rmidi->private_data;
639	char first;
640	static unsigned long lasttime = 0;
641
642	/* Interrupts are disabled during the updating of the tx_buff,
643	* since it is 'bad' to have two processes updating the same
644	* variables (ie buff_in & buff_out)
645	*/
646
647	spin_lock_irqsave(&uart->open_lock, flags);
648
649	if (uart->irq < 0) /* polling */
650	snd_uart16550_io_loop(uart);
651
652	if (uart->adaptor == SNDRV_SERIAL_MS124W_MB) {
653	while (1) {
654	/* buffer full? */
655	/* in this mode we need two bytes of space */
656	if (uart->buff_in_count > TX_BUFF_SIZE - 2)
657	break;
658	if (snd_rawmidi_transmit(substream, &midi_byte, 1) != 1)
659	break;
660	#ifdef SNDRV_SERIAL_MS124W_MB_NOCOMBO
661	/* select exactly one of the four ports */
662	addr_byte = (1 << (substream->number + 4)) \| 0x08;
663	#else
664	/* select any combination of the four ports */
665	addr_byte = (substream->number << 4) \| 0x08;
666	/* ...except none */
667	if (addr_byte == 0x08)
668	addr_byte = 0xf8;
669	#endif
670	snd_uart16550_output_byte(uart, substream, addr_byte);
671	/* send midi byte */
672	snd_uart16550_output_byte(uart, substream, midi_byte);
673	}
674	} else {
675	first = 0;
676	while (snd_rawmidi_transmit_peek(substream, &midi_byte, 1) == 1) {
677	/* Also send F5 after 3 seconds with no data
678	* to handle device disconnect */
679	if (first == 0 &&
680	(uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS \|\|
681	uart->adaptor == SNDRV_SERIAL_GENERIC) &&
682	(uart->prev_out != substream->number \|\|
683	time_after(jiffies, lasttime + 3*HZ))) {
684
685	if (snd_uart16550_buffer_can_write(uart, 3)) {
686	/* Roland Soundcanvas part selection */
687	/* If this substream of the data is
688	* different previous substream
689	* in this uart, send the change part
690	* event
691	*/
692	uart->prev_out = substream->number;
693	/* change part */
694	snd_uart16550_output_byte(uart, substream,
695	0xf5);
696	/* data */
697	snd_uart16550_output_byte(uart, substream,
698	uart->prev_out + 1);
699	/* If midi_byte is a data byte,
700	* send the previous status byte */
701	if (midi_byte < 0x80 &&
702	uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS)
703	snd_uart16550_output_byte(uart, substream, uart->prev_status[uart->prev_out]);
704	} else if (!uart->drop_on_full)
705	break;
706
707	}
708
709	/* send midi byte */
710	if (!snd_uart16550_output_byte(uart, substream, midi_byte) &&
711	!uart->drop_on_full )
712	break;
713
714	if (midi_byte >= 0x80 && midi_byte < 0xf0)
715	uart->prev_status[uart->prev_out] = midi_byte;
716	first = 1;
717
718	snd_rawmidi_transmit_ack( substream, 1 );
719	}
720	lasttime = jiffies;
721	}
722	spin_unlock_irqrestore(&uart->open_lock, flags);
723	}
724
725	static void snd_uart16550_output_trigger(struct snd_rawmidi_substream *substream,
726	int up)
727	{
728	unsigned long flags;
729	struct snd_uart16550 *uart = substream->rmidi->private_data;
730
731	spin_lock_irqsave(&uart->open_lock, flags);
732	if (up)
733	uart->filemode \|= SERIAL_MODE_OUTPUT_TRIGGERED;
734	else
735	uart->filemode &= ~SERIAL_MODE_OUTPUT_TRIGGERED;
736	spin_unlock_irqrestore(&uart->open_lock, flags);
737	if (up)
738	snd_uart16550_output_write(substream);
739	}
740
741	static const struct snd_rawmidi_ops snd_uart16550_output =
742	{
743	.open = snd_uart16550_output_open,
744	.close = snd_uart16550_output_close,
745	.trigger = snd_uart16550_output_trigger,
746	};
747
748	static const struct snd_rawmidi_ops snd_uart16550_input =
749	{
750	.open = snd_uart16550_input_open,
751	.close = snd_uart16550_input_close,
752	.trigger = snd_uart16550_input_trigger,
753	};
754
755	static int snd_uart16550_free(struct snd_uart16550 *uart)
756	{
757	if (uart->irq >= 0)
758	free_irq(uart->irq, uart);
759	release_and_free_resource(uart->res_base);
760	kfree(uart);
761	return 0;
762	};
763
764	static int snd_uart16550_dev_free(struct snd_device *device)
765	{
766	struct snd_uart16550 *uart = device->device_data;
767	return snd_uart16550_free(uart);
768	}
769
770	static int snd_uart16550_create(struct snd_card *card,
771	unsigned long iobase,
772	int irq,
773	unsigned int speed,
774	unsigned int base,
775	int adaptor,
776	int droponfull,
777	struct snd_uart16550 **ruart)
778	{
779	static const struct snd_device_ops ops = {
780	.dev_free = snd_uart16550_dev_free,
781	};
782	struct snd_uart16550 *uart;
783	int err;
784
785
786	if ((uart = kzalloc(sizeof(*uart), GFP_KERNEL)) == NULL)
787	return -ENOMEM;
788	uart->adaptor = adaptor;
789	uart->card = card;
790	spin_lock_init(&uart->open_lock);
791	uart->irq = -1;
792	uart->base = iobase;
793	uart->drop_on_full = droponfull;
794
795	if ((err = snd_uart16550_detect(uart)) <= 0) {
796	printk(KERN_ERR "no UART detected at 0x%lx\n", iobase);
797	snd_uart16550_free(uart);
798	return -ENODEV;
799	}
800
801	if (irq >= 0 && irq != SNDRV_AUTO_IRQ) {
802	if (request_irq(irq, snd_uart16550_interrupt,
803	0, "Serial MIDI", uart)) {
804	snd_printk(KERN_WARNING
805	"irq %d busy. Using Polling.\n", irq);
806	} else {
807	uart->irq = irq;
808	}
809	}
810	uart->divisor = base / speed;
811	uart->speed = base / (unsigned int)uart->divisor;
812	uart->speed_base = base;
813	uart->prev_out = -1;
814	uart->prev_in = 0;
815	uart->rstatus = 0;
816	memset(uart->prev_status, 0x80, sizeof(unsigned char) * SNDRV_SERIAL_MAX_OUTS);
817	timer_setup(&uart->buffer_timer, snd_uart16550_buffer_timer, 0);
818	uart->timer_running = 0;
819
820	/* Register device */
821	if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, uart, &ops)) < 0) {
822	snd_uart16550_free(uart);
823	return err;
824	}
825
826	switch (uart->adaptor) {
827	case SNDRV_SERIAL_MS124W_SA:
828	case SNDRV_SERIAL_MS124W_MB:
829	/* MS-124W can draw power from RTS and DTR if they
830	are in opposite states. */
831	outb(UART_MCR_RTS \| (0&UART_MCR_DTR), uart->base + UART_MCR);
832	break;
833	case SNDRV_SERIAL_MS124T:
834	/* MS-124T can draw power from RTS and/or DTR (preferably
835	both) if they are asserted. */
836	outb(UART_MCR_RTS \| UART_MCR_DTR, uart->base + UART_MCR);
837	break;
838	default:
839	break;
840	}
841
842	if (ruart)
843	*ruart = uart;
844
845	return 0;
846	}
847
848	static void snd_uart16550_substreams(struct snd_rawmidi_str *stream)
849	{
850	struct snd_rawmidi_substream *substream;
851
852	list_for_each_entry(substream, &stream->substreams, list) {
853	sprintf(substream->name, "Serial MIDI %d", substream->number + 1);
854	}
855	}
856
857	static int snd_uart16550_rmidi(struct snd_uart16550 *uart, int device,
858	int outs, int ins,
859	struct snd_rawmidi **rmidi)
860	{
861	struct snd_rawmidi *rrawmidi;
862	int err;
863
864	err = snd_rawmidi_new(uart->card, "UART Serial MIDI", device,
865	outs, ins, &rrawmidi);
866	if (err < 0)
867	return err;
868	snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_INPUT,
869	&snd_uart16550_input);
870	snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
871	&snd_uart16550_output);
872	strcpy(rrawmidi->name, "Serial MIDI");
873	snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
874	snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
875	rrawmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT \|
876	SNDRV_RAWMIDI_INFO_INPUT \|
877	SNDRV_RAWMIDI_INFO_DUPLEX;
878	rrawmidi->private_data = uart;
879	if (rmidi)
880	*rmidi = rrawmidi;
881	return 0;
882	}
883
884	static int snd_serial_probe(struct platform_device *devptr)
885	{
886	struct snd_card *card;
887	struct snd_uart16550 *uart;
888	int err;
889	int dev = devptr->id;
890
891	switch (adaptor[dev]) {
892	case SNDRV_SERIAL_SOUNDCANVAS:
893	ins[dev] = 1;
894	break;
895	case SNDRV_SERIAL_MS124T:
896	case SNDRV_SERIAL_MS124W_SA:
897	outs[dev] = 1;
898	ins[dev] = 1;
899	break;
900	case SNDRV_SERIAL_MS124W_MB:
901	outs[dev] = 16;
902	ins[dev] = 1;
903	break;
904	case SNDRV_SERIAL_GENERIC:
905	break;
906	default:
907	snd_printk(KERN_ERR
908	"Adaptor type is out of range 0-%d (%d)\n",
909	SNDRV_SERIAL_MAX_ADAPTOR, adaptor[dev]);
910	return -ENODEV;
911	}
912
913	if (outs[dev] < 1 \|\| outs[dev] > SNDRV_SERIAL_MAX_OUTS) {
914	snd_printk(KERN_ERR
915	"Count of outputs is out of range 1-%d (%d)\n",
916	SNDRV_SERIAL_MAX_OUTS, outs[dev]);
917	return -ENODEV;
918	}
919
920	if (ins[dev] < 1 \|\| ins[dev] > SNDRV_SERIAL_MAX_INS) {
921	snd_printk(KERN_ERR
922	"Count of inputs is out of range 1-%d (%d)\n",
923	SNDRV_SERIAL_MAX_INS, ins[dev]);
924	return -ENODEV;
925	}
926
927	err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
928	0, &card);
929	if (err < 0)
930	return err;
931
932	strcpy(card->driver, "Serial");
933	strcpy(card->shortname, "Serial MIDI (UART16550A)");
934
935	if ((err = snd_uart16550_create(card,
936	port[dev],
937	irq[dev],
938	speed[dev],
939	base[dev],
940	adaptor[dev],
941	droponfull[dev],
942	&uart)) < 0)
943	goto _err;
944
945	err = snd_uart16550_rmidi(uart, 0, outs[dev], ins[dev], &uart->rmidi);
946	if (err < 0)
947	goto _err;
948
949	sprintf(card->longname, "%s [%s] at %#lx, irq %d",
950	card->shortname,
951	adaptor_names[uart->adaptor],
952	uart->base,
953	uart->irq);
954
955	if ((err = snd_card_register(card)) < 0)
956	goto _err;
957
958	platform_set_drvdata(devptr, card);
959	return 0;
960
961	_err:
962	snd_card_free(card);
963	return err;
964	}
965
966	static int snd_serial_remove(struct platform_device *devptr)
967	{
968	snd_card_free(platform_get_drvdata(devptr));
969	return 0;
970	}
971
972	#define SND_SERIAL_DRIVER "snd_serial_u16550"
973
974	static struct platform_driver snd_serial_driver = {
975	.probe = snd_serial_probe,
976	.remove = snd_serial_remove,
977	.driver = {
978	.name = SND_SERIAL_DRIVER,
979	},
980	};
981
982	static void snd_serial_unregister_all(void)
983	{
984	int i;
985
986	for (i = 0; i < ARRAY_SIZE(devices); ++i)
987	platform_device_unregister(devices[i]);
988	platform_driver_unregister(&snd_serial_driver);
989	}
990
991	static int __init alsa_card_serial_init(void)
992	{
993	int i, cards, err;
994
995	if ((err = platform_driver_register(&snd_serial_driver)) < 0)
996	return err;
997
998	cards = 0;
999	for (i = 0; i < SNDRV_CARDS; i++) {
1000	struct platform_device *device;
1001	if (! enable[i])
1002	continue;
1003	device = platform_device_register_simple(SND_SERIAL_DRIVER,
1004	i, NULL, 0);
1005	if (IS_ERR(device))
1006	continue;
1007	if (!platform_get_drvdata(device)) {
1008	platform_device_unregister(device);
1009	continue;
1010	}
1011	devices[i] = device;
1012	cards++;
1013	}
1014	if (! cards) {
1015	#ifdef MODULE
1016	printk(KERN_ERR "serial midi soundcard not found or device busy\n");
1017	#endif
1018	snd_serial_unregister_all();
1019	return -ENODEV;
1020	}
1021	return 0;
1022	}
1023
1024	static void __exit alsa_card_serial_exit(void)
1025	{
1026	snd_serial_unregister_all();
1027	}
1028
1029	module_init(alsa_card_serial_init)
1030	module_exit(alsa_card_serial_exit)

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