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Linux/sound/drivers/serial-u16550.c

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

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