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
119 unsigned int speed;
120 unsigned int speed_base;
121 unsigned char divisor;
122
123 unsigned char old_divisor_lsb;
124 unsigned char old_divisor_msb;
125 unsigned char old_line_ctrl_reg;
126
127 /* parameter for using of write loop */
128 short int fifo_limit; /* used in uart16550 */
129 short int fifo_count; /* used in uart16550 */
130
131 /* type of adaptor */
132 int adaptor;
133
134 /* inputs */
135 int prev_in;
136 unsigned char rstatus;
137
138 /* outputs */
139 int prev_out;
140 unsigned char prev_status[SNDRV_SERIAL_MAX_OUTS];
141
142 /* write buffer and its writing/reading position */
143 unsigned char tx_buff[TX_BUFF_SIZE];
144 int buff_in_count;
145 int buff_in;
146 int buff_out;
147 int drop_on_full;
148
149 /* wait timer */
150 unsigned int timer_running:1;
151 struct timer_list buffer_timer;
152
153 };
154
155 static struct platform_device *devices[SNDRV_CARDS];
156
snd_uart16550_add_timer(struct snd_uart16550 * uart)157 static inline void snd_uart16550_add_timer(struct snd_uart16550 *uart)
158 {
159 if (!uart->timer_running) {
160 /* timer 38600bps * 10bit * 16byte */
161 mod_timer(&uart->buffer_timer, jiffies + (HZ + 255) / 256);
162 uart->timer_running = 1;
163 }
164 }
165
snd_uart16550_del_timer(struct snd_uart16550 * uart)166 static inline void snd_uart16550_del_timer(struct snd_uart16550 *uart)
167 {
168 if (uart->timer_running) {
169 del_timer(&uart->buffer_timer);
170 uart->timer_running = 0;
171 }
172 }
173
174 /* This macro is only used in snd_uart16550_io_loop */
snd_uart16550_buffer_output(struct snd_uart16550 * uart)175 static inline void snd_uart16550_buffer_output(struct snd_uart16550 *uart)
176 {
177 unsigned short buff_out = uart->buff_out;
178 if (uart->buff_in_count > 0) {
179 outb(uart->tx_buff[buff_out], uart->base + UART_TX);
180 uart->fifo_count++;
181 buff_out++;
182 buff_out &= TX_BUFF_MASK;
183 uart->buff_out = buff_out;
184 uart->buff_in_count--;
185 }
186 }
187
188 /* This loop should be called with interrupts disabled
189 * We don't want to interrupt this,
190 * as we're already handling an interrupt
191 */
snd_uart16550_io_loop(struct snd_uart16550 * uart)192 static void snd_uart16550_io_loop(struct snd_uart16550 * uart)
193 {
194 unsigned char c, status;
195 int substream;
196
197 /* recall previous stream */
198 substream = uart->prev_in;
199
200 /* Read Loop */
201 while ((status = inb(uart->base + UART_LSR)) & UART_LSR_DR) {
202 /* while receive data ready */
203 c = inb(uart->base + UART_RX);
204
205 /* keep track of last status byte */
206 if (c & 0x80)
207 uart->rstatus = c;
208
209 /* handle stream switch */
210 if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
211 if (uart->rstatus == 0xf5) {
212 if (c <= SNDRV_SERIAL_MAX_INS && c > 0)
213 substream = c - 1;
214 if (c != 0xf5)
215 /* prevent future bytes from being
216 interpreted as streams */
217 uart->rstatus = 0;
218 } else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN)
219 && uart->midi_input[substream])
220 snd_rawmidi_receive(uart->midi_input[substream],
221 &c, 1);
222 } else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) &&
223 uart->midi_input[substream])
224 snd_rawmidi_receive(uart->midi_input[substream], &c, 1);
225
226 if (status & UART_LSR_OE)
227 dev_warn(uart->card->dev,
228 "%s: Overrun on device at 0x%lx\n",
229 uart->rmidi->name, uart->base);
230 }
231
232 /* remember the last stream */
233 uart->prev_in = substream;
234
235 /* no need of check SERIAL_MODE_OUTPUT_OPEN because if not,
236 buffer is never filled. */
237 /* Check write status */
238 if (status & UART_LSR_THRE)
239 uart->fifo_count = 0;
240 if (uart->adaptor == SNDRV_SERIAL_MS124W_SA
241 || uart->adaptor == SNDRV_SERIAL_GENERIC) {
242 /* Can't use FIFO, must send only when CTS is true */
243 status = inb(uart->base + UART_MSR);
244 while (uart->fifo_count == 0 && (status & UART_MSR_CTS) &&
245 uart->buff_in_count > 0) {
246 snd_uart16550_buffer_output(uart);
247 status = inb(uart->base + UART_MSR);
248 }
249 } else {
250 /* Write loop */
251 while (uart->fifo_count < uart->fifo_limit /* Can we write ? */
252 && uart->buff_in_count > 0) /* Do we want to? */
253 snd_uart16550_buffer_output(uart);
254 }
255 if (uart->irq < 0 && uart->buff_in_count > 0)
256 snd_uart16550_add_timer(uart);
257 }
258
259 /* NOTES ON SERVICING INTERUPTS
260 * ---------------------------
261 * After receiving a interrupt, it is important to indicate to the UART that
262 * this has been done.
263 * For a Rx interrupt, this is done by reading the received byte.
264 * For a Tx interrupt this is done by either:
265 * a) Writing a byte
266 * b) Reading the IIR
267 * It is particularly important to read the IIR if a Tx interrupt is received
268 * when there is no data in tx_buff[], as in this case there no other
269 * indication that the interrupt has been serviced, and it remains outstanding
270 * indefinitely. This has the curious side effect that and no further interrupts
271 * will be generated from this device AT ALL!!.
272 * It is also desirable to clear outstanding interrupts when the device is
273 * opened/closed.
274 *
275 *
276 * Note that some devices need OUT2 to be set before they will generate
277 * interrupts at all. (Possibly tied to an internal pull-up on CTS?)
278 */
snd_uart16550_interrupt(int irq,void * dev_id)279 static irqreturn_t snd_uart16550_interrupt(int irq, void *dev_id)
280 {
281 struct snd_uart16550 *uart;
282
283 uart = dev_id;
284 spin_lock(&uart->open_lock);
285 if (uart->filemode == SERIAL_MODE_NOT_OPENED) {
286 spin_unlock(&uart->open_lock);
287 return IRQ_NONE;
288 }
289 /* indicate to the UART that the interrupt has been serviced */
290 inb(uart->base + UART_IIR);
291 snd_uart16550_io_loop(uart);
292 spin_unlock(&uart->open_lock);
293 return IRQ_HANDLED;
294 }
295
296 /* When the polling mode, this function calls snd_uart16550_io_loop. */
snd_uart16550_buffer_timer(struct timer_list * t)297 static void snd_uart16550_buffer_timer(struct timer_list *t)
298 {
299 unsigned long flags;
300 struct snd_uart16550 *uart;
301
302 uart = from_timer(uart, t, buffer_timer);
303 spin_lock_irqsave(&uart->open_lock, flags);
304 snd_uart16550_del_timer(uart);
305 snd_uart16550_io_loop(uart);
306 spin_unlock_irqrestore(&uart->open_lock, flags);
307 }
308
309 /*
310 * this method probes, if an uart sits on given port
311 * return 0 if found
312 * return negative error if not found
313 */
snd_uart16550_detect(struct snd_uart16550 * uart)314 static int snd_uart16550_detect(struct snd_uart16550 *uart)
315 {
316 unsigned long io_base = uart->base;
317 int ok;
318 unsigned char c;
319
320 /* Do some vague tests for the presence of the uart */
321 if (io_base == 0 || io_base == SNDRV_AUTO_PORT) {
322 return -ENODEV; /* Not configured */
323 }
324
325 if (!devm_request_region(uart->card->dev, io_base, 8, "Serial MIDI")) {
326 dev_err(uart->card->dev,
327 "u16550: can't grab port 0x%lx\n", io_base);
328 return -EBUSY;
329 }
330
331 /* uart detected unless one of the following tests should fail */
332 ok = 1;
333 /* 8 data-bits, 1 stop-bit, parity off, DLAB = 0 */
334 outb(UART_LCR_WLEN8, io_base + UART_LCR); /* Line Control Register */
335 c = inb(io_base + UART_IER);
336 /* The top four bits of the IER should always == 0 */
337 if ((c & 0xf0) != 0)
338 ok = 0; /* failed */
339
340 outb(0xaa, io_base + UART_SCR);
341 /* Write arbitrary data into the scratch reg */
342 c = inb(io_base + UART_SCR);
343 /* If it comes back, it's OK */
344 if (c != 0xaa)
345 ok = 0; /* failed */
346
347 outb(0x55, io_base + UART_SCR);
348 /* Write arbitrary data into the scratch reg */
349 c = inb(io_base + UART_SCR);
350 /* If it comes back, it's OK */
351 if (c != 0x55)
352 ok = 0; /* failed */
353
354 return ok;
355 }
356
snd_uart16550_do_open(struct snd_uart16550 * uart)357 static void snd_uart16550_do_open(struct snd_uart16550 * uart)
358 {
359 char byte;
360
361 /* Initialize basic variables */
362 uart->buff_in_count = 0;
363 uart->buff_in = 0;
364 uart->buff_out = 0;
365 uart->fifo_limit = 1;
366 uart->fifo_count = 0;
367 uart->timer_running = 0;
368
369 outb(UART_FCR_ENABLE_FIFO /* Enable FIFO's (if available) */
370 | UART_FCR_CLEAR_RCVR /* Clear receiver FIFO */
371 | UART_FCR_CLEAR_XMIT /* Clear transmitter FIFO */
372 | UART_FCR_TRIGGER_4 /* Set FIFO trigger at 4-bytes */
373 /* NOTE: interrupt generated after T=(time)4-bytes
374 * if less than UART_FCR_TRIGGER bytes received
375 */
376 ,uart->base + UART_FCR); /* FIFO Control Register */
377
378 if ((inb(uart->base + UART_IIR) & 0xf0) == 0xc0)
379 uart->fifo_limit = 16;
380 if (uart->divisor != 0) {
381 uart->old_line_ctrl_reg = inb(uart->base + UART_LCR);
382 outb(UART_LCR_DLAB /* Divisor latch access bit */
383 ,uart->base + UART_LCR); /* Line Control Register */
384 uart->old_divisor_lsb = inb(uart->base + UART_DLL);
385 uart->old_divisor_msb = inb(uart->base + UART_DLM);
386
387 outb(uart->divisor
388 ,uart->base + UART_DLL); /* Divisor Latch Low */
389 outb(0
390 ,uart->base + UART_DLM); /* Divisor Latch High */
391 /* DLAB is reset to 0 in next outb() */
392 }
393 /* Set serial parameters (parity off, etc) */
394 outb(UART_LCR_WLEN8 /* 8 data-bits */
395 | 0 /* 1 stop-bit */
396 | 0 /* parity off */
397 | 0 /* DLAB = 0 */
398 ,uart->base + UART_LCR); /* Line Control Register */
399
400 switch (uart->adaptor) {
401 default:
402 outb(UART_MCR_RTS /* Set Request-To-Send line active */
403 | UART_MCR_DTR /* Set Data-Terminal-Ready line active */
404 | UART_MCR_OUT2 /* Set OUT2 - not always required, but when
405 * it is, it is ESSENTIAL for enabling interrupts
406 */
407 ,uart->base + UART_MCR); /* Modem Control Register */
408 break;
409 case SNDRV_SERIAL_MS124W_SA:
410 case SNDRV_SERIAL_MS124W_MB:
411 /* MS-124W can draw power from RTS and DTR if they
412 are in opposite states. */
413 outb(UART_MCR_RTS | (0&UART_MCR_DTR) | UART_MCR_OUT2,
414 uart->base + UART_MCR);
415 break;
416 case SNDRV_SERIAL_MS124T:
417 /* MS-124T can draw power from RTS and/or DTR (preferably
418 both) if they are both asserted. */
419 outb(UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2,
420 uart->base + UART_MCR);
421 break;
422 }
423
424 if (uart->irq < 0) {
425 byte = (0 & UART_IER_RDI) /* Disable Receiver data interrupt */
426 |(0 & UART_IER_THRI) /* Disable Transmitter holding register empty interrupt */
427 ;
428 } else if (uart->adaptor == SNDRV_SERIAL_MS124W_SA) {
429 byte = UART_IER_RDI /* Enable Receiver data interrupt */
430 | UART_IER_MSI /* Enable Modem status interrupt */
431 ;
432 } else if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
433 byte = UART_IER_RDI /* Enable Receiver data interrupt */
434 | UART_IER_MSI /* Enable Modem status interrupt */
435 | UART_IER_THRI /* Enable Transmitter holding register empty interrupt */
436 ;
437 } else {
438 byte = UART_IER_RDI /* Enable Receiver data interrupt */
439 | UART_IER_THRI /* Enable Transmitter holding register empty interrupt */
440 ;
441 }
442 outb(byte, uart->base + UART_IER); /* Interrupt enable Register */
443
444 inb(uart->base + UART_LSR); /* Clear any pre-existing overrun indication */
445 inb(uart->base + UART_IIR); /* Clear any pre-existing transmit interrupt */
446 inb(uart->base + UART_RX); /* Clear any pre-existing receive interrupt */
447 }
448
snd_uart16550_do_close(struct snd_uart16550 * uart)449 static void snd_uart16550_do_close(struct snd_uart16550 * uart)
450 {
451 if (uart->irq < 0)
452 snd_uart16550_del_timer(uart);
453
454 /* NOTE: may need to disable interrupts before de-registering out handler.
455 * For now, the consequences are harmless.
456 */
457
458 outb((0 & UART_IER_RDI) /* Disable Receiver data interrupt */
459 |(0 & UART_IER_THRI) /* Disable Transmitter holding register empty interrupt */
460 ,uart->base + UART_IER); /* Interrupt enable Register */
461
462 switch (uart->adaptor) {
463 default:
464 outb((0 & UART_MCR_RTS) /* Deactivate Request-To-Send line */
465 |(0 & UART_MCR_DTR) /* Deactivate Data-Terminal-Ready line */
466 |(0 & UART_MCR_OUT2) /* Deactivate OUT2 */
467 ,uart->base + UART_MCR); /* Modem Control Register */
468 break;
469 case SNDRV_SERIAL_MS124W_SA:
470 case SNDRV_SERIAL_MS124W_MB:
471 /* MS-124W can draw power from RTS and DTR if they
472 are in opposite states; leave it powered. */
473 outb(UART_MCR_RTS | (0&UART_MCR_DTR) | (0&UART_MCR_OUT2),
474 uart->base + UART_MCR);
475 break;
476 case SNDRV_SERIAL_MS124T:
477 /* MS-124T can draw power from RTS and/or DTR (preferably
478 both) if they are both asserted; leave it powered. */
479 outb(UART_MCR_RTS | UART_MCR_DTR | (0&UART_MCR_OUT2),
480 uart->base + UART_MCR);
481 break;
482 }
483
484 inb(uart->base + UART_IIR); /* Clear any outstanding interrupts */
485
486 /* Restore old divisor */
487 if (uart->divisor != 0) {
488 outb(UART_LCR_DLAB /* Divisor latch access bit */
489 ,uart->base + UART_LCR); /* Line Control Register */
490 outb(uart->old_divisor_lsb
491 ,uart->base + UART_DLL); /* Divisor Latch Low */
492 outb(uart->old_divisor_msb
493 ,uart->base + UART_DLM); /* Divisor Latch High */
494 /* Restore old LCR (data bits, stop bits, parity, DLAB) */
495 outb(uart->old_line_ctrl_reg
496 ,uart->base + UART_LCR); /* Line Control Register */
497 }
498 }
499
snd_uart16550_input_open(struct snd_rawmidi_substream * substream)500 static int snd_uart16550_input_open(struct snd_rawmidi_substream *substream)
501 {
502 unsigned long flags;
503 struct snd_uart16550 *uart = substream->rmidi->private_data;
504
505 spin_lock_irqsave(&uart->open_lock, flags);
506 if (uart->filemode == SERIAL_MODE_NOT_OPENED)
507 snd_uart16550_do_open(uart);
508 uart->filemode |= SERIAL_MODE_INPUT_OPEN;
509 uart->midi_input[substream->number] = substream;
510 spin_unlock_irqrestore(&uart->open_lock, flags);
511 return 0;
512 }
513
snd_uart16550_input_close(struct snd_rawmidi_substream * substream)514 static int snd_uart16550_input_close(struct snd_rawmidi_substream *substream)
515 {
516 unsigned long flags;
517 struct snd_uart16550 *uart = substream->rmidi->private_data;
518
519 spin_lock_irqsave(&uart->open_lock, flags);
520 uart->filemode &= ~SERIAL_MODE_INPUT_OPEN;
521 uart->midi_input[substream->number] = NULL;
522 if (uart->filemode == SERIAL_MODE_NOT_OPENED)
523 snd_uart16550_do_close(uart);
524 spin_unlock_irqrestore(&uart->open_lock, flags);
525 return 0;
526 }
527
snd_uart16550_input_trigger(struct snd_rawmidi_substream * substream,int up)528 static void snd_uart16550_input_trigger(struct snd_rawmidi_substream *substream,
529 int up)
530 {
531 unsigned long flags;
532 struct snd_uart16550 *uart = substream->rmidi->private_data;
533
534 spin_lock_irqsave(&uart->open_lock, flags);
535 if (up)
536 uart->filemode |= SERIAL_MODE_INPUT_TRIGGERED;
537 else
538 uart->filemode &= ~SERIAL_MODE_INPUT_TRIGGERED;
539 spin_unlock_irqrestore(&uart->open_lock, flags);
540 }
541
snd_uart16550_output_open(struct snd_rawmidi_substream * substream)542 static int snd_uart16550_output_open(struct snd_rawmidi_substream *substream)
543 {
544 unsigned long flags;
545 struct snd_uart16550 *uart = substream->rmidi->private_data;
546
547 spin_lock_irqsave(&uart->open_lock, flags);
548 if (uart->filemode == SERIAL_MODE_NOT_OPENED)
549 snd_uart16550_do_open(uart);
550 uart->filemode |= SERIAL_MODE_OUTPUT_OPEN;
551 uart->midi_output[substream->number] = substream;
552 spin_unlock_irqrestore(&uart->open_lock, flags);
553 return 0;
554 };
555
snd_uart16550_output_close(struct snd_rawmidi_substream * substream)556 static int snd_uart16550_output_close(struct snd_rawmidi_substream *substream)
557 {
558 unsigned long flags;
559 struct snd_uart16550 *uart = substream->rmidi->private_data;
560
561 spin_lock_irqsave(&uart->open_lock, flags);
562 uart->filemode &= ~SERIAL_MODE_OUTPUT_OPEN;
563 uart->midi_output[substream->number] = NULL;
564 if (uart->filemode == SERIAL_MODE_NOT_OPENED)
565 snd_uart16550_do_close(uart);
566 spin_unlock_irqrestore(&uart->open_lock, flags);
567 return 0;
568 };
569
snd_uart16550_buffer_can_write(struct snd_uart16550 * uart,int Num)570 static inline int snd_uart16550_buffer_can_write(struct snd_uart16550 *uart,
571 int Num)
572 {
573 if (uart->buff_in_count + Num < TX_BUFF_SIZE)
574 return 1;
575 else
576 return 0;
577 }
578
snd_uart16550_write_buffer(struct snd_uart16550 * uart,unsigned char byte)579 static inline int snd_uart16550_write_buffer(struct snd_uart16550 *uart,
580 unsigned char byte)
581 {
582 unsigned short buff_in = uart->buff_in;
583 if (uart->buff_in_count < TX_BUFF_SIZE) {
584 uart->tx_buff[buff_in] = byte;
585 buff_in++;
586 buff_in &= TX_BUFF_MASK;
587 uart->buff_in = buff_in;
588 uart->buff_in_count++;
589 if (uart->irq < 0) /* polling mode */
590 snd_uart16550_add_timer(uart);
591 return 1;
592 } else
593 return 0;
594 }
595
snd_uart16550_output_byte(struct snd_uart16550 * uart,struct snd_rawmidi_substream * substream,unsigned char midi_byte)596 static int snd_uart16550_output_byte(struct snd_uart16550 *uart,
597 struct snd_rawmidi_substream *substream,
598 unsigned char midi_byte)
599 {
600 if (uart->buff_in_count == 0 /* Buffer empty? */
601 && ((uart->adaptor != SNDRV_SERIAL_MS124W_SA &&
602 uart->adaptor != SNDRV_SERIAL_GENERIC) ||
603 (uart->fifo_count == 0 /* FIFO empty? */
604 && (inb(uart->base + UART_MSR) & UART_MSR_CTS)))) { /* CTS? */
605
606 /* Tx Buffer Empty - try to write immediately */
607 if ((inb(uart->base + UART_LSR) & UART_LSR_THRE) != 0) {
608 /* Transmitter holding register (and Tx FIFO) empty */
609 uart->fifo_count = 1;
610 outb(midi_byte, uart->base + UART_TX);
611 } else {
612 if (uart->fifo_count < uart->fifo_limit) {
613 uart->fifo_count++;
614 outb(midi_byte, uart->base + UART_TX);
615 } else {
616 /* Cannot write (buffer empty) -
617 * put char in buffer */
618 snd_uart16550_write_buffer(uart, midi_byte);
619 }
620 }
621 } else {
622 if (!snd_uart16550_write_buffer(uart, midi_byte)) {
623 dev_warn(uart->card->dev,
624 "%s: Buffer overrun on device at 0x%lx\n",
625 uart->rmidi->name, uart->base);
626 return 0;
627 }
628 }
629
630 return 1;
631 }
632
snd_uart16550_output_write(struct snd_rawmidi_substream * substream)633 static void snd_uart16550_output_write(struct snd_rawmidi_substream *substream)
634 {
635 unsigned long flags;
636 unsigned char midi_byte, addr_byte;
637 struct snd_uart16550 *uart = substream->rmidi->private_data;
638 char first;
639 static unsigned long lasttime = 0;
640
641 /* Interrupts are disabled during the updating of the tx_buff,
642 * since it is 'bad' to have two processes updating the same
643 * variables (ie buff_in & buff_out)
644 */
645
646 spin_lock_irqsave(&uart->open_lock, flags);
647
648 if (uart->irq < 0) /* polling */
649 snd_uart16550_io_loop(uart);
650
651 if (uart->adaptor == SNDRV_SERIAL_MS124W_MB) {
652 while (1) {
653 /* buffer full? */
654 /* in this mode we need two bytes of space */
655 if (uart->buff_in_count > TX_BUFF_SIZE - 2)
656 break;
657 if (snd_rawmidi_transmit(substream, &midi_byte, 1) != 1)
658 break;
659 #ifdef SNDRV_SERIAL_MS124W_MB_NOCOMBO
660 /* select exactly one of the four ports */
661 addr_byte = (1 << (substream->number + 4)) | 0x08;
662 #else
663 /* select any combination of the four ports */
664 addr_byte = (substream->number << 4) | 0x08;
665 /* ...except none */
666 if (addr_byte == 0x08)
667 addr_byte = 0xf8;
668 #endif
669 snd_uart16550_output_byte(uart, substream, addr_byte);
670 /* send midi byte */
671 snd_uart16550_output_byte(uart, substream, midi_byte);
672 }
673 } else {
674 first = 0;
675 while (snd_rawmidi_transmit_peek(substream, &midi_byte, 1) == 1) {
676 /* Also send F5 after 3 seconds with no data
677 * to handle device disconnect */
678 if (first == 0 &&
679 (uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS ||
680 uart->adaptor == SNDRV_SERIAL_GENERIC) &&
681 (uart->prev_out != substream->number ||
682 time_after(jiffies, lasttime + 3*HZ))) {
683
684 if (snd_uart16550_buffer_can_write(uart, 3)) {
685 /* Roland Soundcanvas part selection */
686 /* If this substream of the data is
687 * different previous substream
688 * in this uart, send the change part
689 * event
690 */
691 uart->prev_out = substream->number;
692 /* change part */
693 snd_uart16550_output_byte(uart, substream,
694 0xf5);
695 /* data */
696 snd_uart16550_output_byte(uart, substream,
697 uart->prev_out + 1);
698 /* If midi_byte is a data byte,
699 * send the previous status byte */
700 if (midi_byte < 0x80 &&
701 uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS)
702 snd_uart16550_output_byte(uart, substream, uart->prev_status[uart->prev_out]);
703 } else if (!uart->drop_on_full)
704 break;
705
706 }
707
708 /* send midi byte */
709 if (!snd_uart16550_output_byte(uart, substream, midi_byte) &&
710 !uart->drop_on_full )
711 break;
712
713 if (midi_byte >= 0x80 && midi_byte < 0xf0)
714 uart->prev_status[uart->prev_out] = midi_byte;
715 first = 1;
716
717 snd_rawmidi_transmit_ack( substream, 1 );
718 }
719 lasttime = jiffies;
720 }
721 spin_unlock_irqrestore(&uart->open_lock, flags);
722 }
723
snd_uart16550_output_trigger(struct snd_rawmidi_substream * substream,int up)724 static void snd_uart16550_output_trigger(struct snd_rawmidi_substream *substream,
725 int up)
726 {
727 unsigned long flags;
728 struct snd_uart16550 *uart = substream->rmidi->private_data;
729
730 spin_lock_irqsave(&uart->open_lock, flags);
731 if (up)
732 uart->filemode |= SERIAL_MODE_OUTPUT_TRIGGERED;
733 else
734 uart->filemode &= ~SERIAL_MODE_OUTPUT_TRIGGERED;
735 spin_unlock_irqrestore(&uart->open_lock, flags);
736 if (up)
737 snd_uart16550_output_write(substream);
738 }
739
740 static const struct snd_rawmidi_ops snd_uart16550_output =
741 {
742 .open = snd_uart16550_output_open,
743 .close = snd_uart16550_output_close,
744 .trigger = snd_uart16550_output_trigger,
745 };
746
747 static const struct snd_rawmidi_ops snd_uart16550_input =
748 {
749 .open = snd_uart16550_input_open,
750 .close = snd_uart16550_input_close,
751 .trigger = snd_uart16550_input_trigger,
752 };
753
snd_uart16550_create(struct snd_card * card,unsigned long iobase,int irq,unsigned int speed,unsigned int base,int adaptor,int droponfull,struct snd_uart16550 ** ruart)754 static int snd_uart16550_create(struct snd_card *card,
755 unsigned long iobase,
756 int irq,
757 unsigned int speed,
758 unsigned int base,
759 int adaptor,
760 int droponfull,
761 struct snd_uart16550 **ruart)
762 {
763 struct snd_uart16550 *uart;
764 int err;
765
766
767 uart = devm_kzalloc(card->dev, sizeof(*uart), GFP_KERNEL);
768 if (!uart)
769 return -ENOMEM;
770 uart->adaptor = adaptor;
771 uart->card = card;
772 spin_lock_init(&uart->open_lock);
773 uart->irq = -1;
774 uart->base = iobase;
775 uart->drop_on_full = droponfull;
776
777 err = snd_uart16550_detect(uart);
778 if (err <= 0) {
779 dev_err(card->dev, "no UART detected at 0x%lx\n", iobase);
780 return -ENODEV;
781 }
782
783 if (irq >= 0 && irq != SNDRV_AUTO_IRQ) {
784 if (devm_request_irq(card->dev, irq, snd_uart16550_interrupt,
785 0, "Serial MIDI", uart)) {
786 dev_warn(card->dev,
787 "irq %d busy. Using Polling.\n", irq);
788 } else {
789 uart->irq = irq;
790 }
791 }
792 uart->divisor = base / speed;
793 uart->speed = base / (unsigned int)uart->divisor;
794 uart->speed_base = base;
795 uart->prev_out = -1;
796 uart->prev_in = 0;
797 uart->rstatus = 0;
798 memset(uart->prev_status, 0x80, sizeof(unsigned char) * SNDRV_SERIAL_MAX_OUTS);
799 timer_setup(&uart->buffer_timer, snd_uart16550_buffer_timer, 0);
800 uart->timer_running = 0;
801
802 switch (uart->adaptor) {
803 case SNDRV_SERIAL_MS124W_SA:
804 case SNDRV_SERIAL_MS124W_MB:
805 /* MS-124W can draw power from RTS and DTR if they
806 are in opposite states. */
807 outb(UART_MCR_RTS | (0&UART_MCR_DTR), uart->base + UART_MCR);
808 break;
809 case SNDRV_SERIAL_MS124T:
810 /* MS-124T can draw power from RTS and/or DTR (preferably
811 both) if they are asserted. */
812 outb(UART_MCR_RTS | UART_MCR_DTR, uart->base + UART_MCR);
813 break;
814 default:
815 break;
816 }
817
818 if (ruart)
819 *ruart = uart;
820
821 return 0;
822 }
823
snd_uart16550_substreams(struct snd_rawmidi_str * stream)824 static void snd_uart16550_substreams(struct snd_rawmidi_str *stream)
825 {
826 struct snd_rawmidi_substream *substream;
827
828 list_for_each_entry(substream, &stream->substreams, list) {
829 sprintf(substream->name, "Serial MIDI %d", substream->number + 1);
830 }
831 }
832
snd_uart16550_rmidi(struct snd_uart16550 * uart,int device,int outs,int ins,struct snd_rawmidi ** rmidi)833 static int snd_uart16550_rmidi(struct snd_uart16550 *uart, int device,
834 int outs, int ins,
835 struct snd_rawmidi **rmidi)
836 {
837 struct snd_rawmidi *rrawmidi;
838 int err;
839
840 err = snd_rawmidi_new(uart->card, "UART Serial MIDI", device,
841 outs, ins, &rrawmidi);
842 if (err < 0)
843 return err;
844 snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_INPUT,
845 &snd_uart16550_input);
846 snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
847 &snd_uart16550_output);
848 strcpy(rrawmidi->name, "Serial MIDI");
849 snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
850 snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
851 rrawmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
852 SNDRV_RAWMIDI_INFO_INPUT |
853 SNDRV_RAWMIDI_INFO_DUPLEX;
854 rrawmidi->private_data = uart;
855 if (rmidi)
856 *rmidi = rrawmidi;
857 return 0;
858 }
859
snd_serial_probe(struct platform_device * devptr)860 static int snd_serial_probe(struct platform_device *devptr)
861 {
862 struct snd_card *card;
863 struct snd_uart16550 *uart;
864 int err;
865 int dev = devptr->id;
866
867 switch (adaptor[dev]) {
868 case SNDRV_SERIAL_SOUNDCANVAS:
869 ins[dev] = 1;
870 break;
871 case SNDRV_SERIAL_MS124T:
872 case SNDRV_SERIAL_MS124W_SA:
873 outs[dev] = 1;
874 ins[dev] = 1;
875 break;
876 case SNDRV_SERIAL_MS124W_MB:
877 outs[dev] = 16;
878 ins[dev] = 1;
879 break;
880 case SNDRV_SERIAL_GENERIC:
881 break;
882 default:
883 dev_err(&devptr->dev,
884 "Adaptor type is out of range 0-%d (%d)\n",
885 SNDRV_SERIAL_MAX_ADAPTOR, adaptor[dev]);
886 return -ENODEV;
887 }
888
889 if (outs[dev] < 1 || outs[dev] > SNDRV_SERIAL_MAX_OUTS) {
890 dev_err(&devptr->dev,
891 "Count of outputs is out of range 1-%d (%d)\n",
892 SNDRV_SERIAL_MAX_OUTS, outs[dev]);
893 return -ENODEV;
894 }
895
896 if (ins[dev] < 1 || ins[dev] > SNDRV_SERIAL_MAX_INS) {
897 dev_err(&devptr->dev,
898 "Count of inputs is out of range 1-%d (%d)\n",
899 SNDRV_SERIAL_MAX_INS, ins[dev]);
900 return -ENODEV;
901 }
902
903 err = snd_devm_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
904 0, &card);
905 if (err < 0)
906 return err;
907
908 strcpy(card->driver, "Serial");
909 strcpy(card->shortname, "Serial MIDI (UART16550A)");
910
911 err = snd_uart16550_create(card, port[dev], irq[dev], speed[dev],
912 base[dev], adaptor[dev], droponfull[dev],
913 &uart);
914 if (err < 0)
915 return err;
916
917 err = snd_uart16550_rmidi(uart, 0, outs[dev], ins[dev], &uart->rmidi);
918 if (err < 0)
919 return err;
920
921 sprintf(card->longname, "%s [%s] at %#lx, irq %d",
922 card->shortname,
923 adaptor_names[uart->adaptor],
924 uart->base,
925 uart->irq);
926
927 err = snd_card_register(card);
928 if (err < 0)
929 return err;
930
931 platform_set_drvdata(devptr, card);
932 return 0;
933 }
934
935 #define SND_SERIAL_DRIVER "snd_serial_u16550"
936
937 static struct platform_driver snd_serial_driver = {
938 .probe = snd_serial_probe,
939 .driver = {
940 .name = SND_SERIAL_DRIVER,
941 },
942 };
943
snd_serial_unregister_all(void)944 static void snd_serial_unregister_all(void)
945 {
946 int i;
947
948 for (i = 0; i < ARRAY_SIZE(devices); ++i)
949 platform_device_unregister(devices[i]);
950 platform_driver_unregister(&snd_serial_driver);
951 }
952
alsa_card_serial_init(void)953 static int __init alsa_card_serial_init(void)
954 {
955 int i, cards, err;
956
957 err = platform_driver_register(&snd_serial_driver);
958 if (err < 0)
959 return err;
960
961 cards = 0;
962 for (i = 0; i < SNDRV_CARDS; i++) {
963 struct platform_device *device;
964 if (! enable[i])
965 continue;
966 device = platform_device_register_simple(SND_SERIAL_DRIVER,
967 i, NULL, 0);
968 if (IS_ERR(device))
969 continue;
970 if (!platform_get_drvdata(device)) {
971 platform_device_unregister(device);
972 continue;
973 }
974 devices[i] = device;
975 cards++;
976 }
977 if (! cards) {
978 #ifdef MODULE
979 pr_err("serial midi soundcard not found or device busy\n");
980 #endif
981 snd_serial_unregister_all();
982 return -ENODEV;
983 }
984 return 0;
985 }
986
alsa_card_serial_exit(void)987 static void __exit alsa_card_serial_exit(void)
988 {
989 snd_serial_unregister_all();
990 }
991
992 module_init(alsa_card_serial_init)
993 module_exit(alsa_card_serial_exit)
994