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