ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED
[deliverable/linux.git] / drivers / tty / serial / bfin_sport_uart.c
1 /*
2 * Blackfin On-Chip Sport Emulated UART Driver
3 *
4 * Copyright 2006-2009 Analog Devices Inc.
5 *
6 * Enter bugs at http://blackfin.uclinux.org/
7 *
8 * Licensed under the GPL-2 or later.
9 */
10
11 /*
12 * This driver and the hardware supported are in term of EE-191 of ADI.
13 * http://www.analog.com/static/imported-files/application_notes/EE191.pdf
14 * This application note describe how to implement a UART on a Sharc DSP,
15 * but this driver is implemented on Blackfin Processor.
16 * Transmit Frame Sync is not used by this driver to transfer data out.
17 */
18
19 /* #define DEBUG */
20
21 #define DRV_NAME "bfin-sport-uart"
22 #define DEVICE_NAME "ttySS"
23 #define pr_fmt(fmt) DRV_NAME ": " fmt
24
25 #include <linux/module.h>
26 #include <linux/ioport.h>
27 #include <linux/io.h>
28 #include <linux/init.h>
29 #include <linux/console.h>
30 #include <linux/sysrq.h>
31 #include <linux/slab.h>
32 #include <linux/platform_device.h>
33 #include <linux/tty.h>
34 #include <linux/tty_flip.h>
35 #include <linux/serial_core.h>
36
37 #include <asm/bfin_sport.h>
38 #include <asm/delay.h>
39 #include <asm/portmux.h>
40
41 #include "bfin_sport_uart.h"
42
43 struct sport_uart_port {
44 struct uart_port port;
45 int err_irq;
46 unsigned short csize;
47 unsigned short rxmask;
48 unsigned short txmask1;
49 unsigned short txmask2;
50 unsigned char stopb;
51 /* unsigned char parib; */
52 #ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
53 int cts_pin;
54 int rts_pin;
55 #endif
56 };
57
58 static int sport_uart_tx_chars(struct sport_uart_port *up);
59 static void sport_stop_tx(struct uart_port *port);
60
61 static inline void tx_one_byte(struct sport_uart_port *up, unsigned int value)
62 {
63 pr_debug("%s value:%x, mask1=0x%x, mask2=0x%x\n", __func__, value,
64 up->txmask1, up->txmask2);
65
66 /* Place Start and Stop bits */
67 __asm__ __volatile__ (
68 "%[val] <<= 1;"
69 "%[val] = %[val] & %[mask1];"
70 "%[val] = %[val] | %[mask2];"
71 : [val]"+d"(value)
72 : [mask1]"d"(up->txmask1), [mask2]"d"(up->txmask2)
73 : "ASTAT"
74 );
75 pr_debug("%s value:%x\n", __func__, value);
76
77 SPORT_PUT_TX(up, value);
78 }
79
80 static inline unsigned char rx_one_byte(struct sport_uart_port *up)
81 {
82 unsigned int value;
83 unsigned char extract;
84 u32 tmp_mask1, tmp_mask2, tmp_shift, tmp;
85
86 if ((up->csize + up->stopb) > 7)
87 value = SPORT_GET_RX32(up);
88 else
89 value = SPORT_GET_RX(up);
90
91 pr_debug("%s value:%x, cs=%d, mask=0x%x\n", __func__, value,
92 up->csize, up->rxmask);
93
94 /* Extract data */
95 __asm__ __volatile__ (
96 "%[extr] = 0;"
97 "%[mask1] = %[rxmask];"
98 "%[mask2] = 0x0200(Z);"
99 "%[shift] = 0;"
100 "LSETUP(.Lloop_s, .Lloop_e) LC0 = %[lc];"
101 ".Lloop_s:"
102 "%[tmp] = extract(%[val], %[mask1].L)(Z);"
103 "%[tmp] <<= %[shift];"
104 "%[extr] = %[extr] | %[tmp];"
105 "%[mask1] = %[mask1] - %[mask2];"
106 ".Lloop_e:"
107 "%[shift] += 1;"
108 : [extr]"=&d"(extract), [shift]"=&d"(tmp_shift), [tmp]"=&d"(tmp),
109 [mask1]"=&d"(tmp_mask1), [mask2]"=&d"(tmp_mask2)
110 : [val]"d"(value), [rxmask]"d"(up->rxmask), [lc]"a"(up->csize)
111 : "ASTAT", "LB0", "LC0", "LT0"
112 );
113
114 pr_debug(" extract:%x\n", extract);
115 return extract;
116 }
117
118 static int sport_uart_setup(struct sport_uart_port *up, int size, int baud_rate)
119 {
120 int tclkdiv, rclkdiv;
121 unsigned int sclk = get_sclk();
122
123 /* Set TCR1 and TCR2, TFSR is not enabled for uart */
124 SPORT_PUT_TCR1(up, (LATFS | ITFS | TFSR | TLSBIT | ITCLK));
125 SPORT_PUT_TCR2(up, size + 1);
126 pr_debug("%s TCR1:%x, TCR2:%x\n", __func__, SPORT_GET_TCR1(up), SPORT_GET_TCR2(up));
127
128 /* Set RCR1 and RCR2 */
129 SPORT_PUT_RCR1(up, (RCKFE | LARFS | LRFS | RFSR | IRCLK));
130 SPORT_PUT_RCR2(up, (size + 1) * 2 - 1);
131 pr_debug("%s RCR1:%x, RCR2:%x\n", __func__, SPORT_GET_RCR1(up), SPORT_GET_RCR2(up));
132
133 tclkdiv = sclk / (2 * baud_rate) - 1;
134 /* The actual uart baud rate of devices vary between +/-2%. The sport
135 * RX sample rate should be faster than the double of the worst case,
136 * otherwise, wrong data are received. So, set sport RX clock to be
137 * 3% faster.
138 */
139 rclkdiv = sclk / (2 * baud_rate * 2 * 97 / 100) - 1;
140 SPORT_PUT_TCLKDIV(up, tclkdiv);
141 SPORT_PUT_RCLKDIV(up, rclkdiv);
142 SSYNC();
143 pr_debug("%s sclk:%d, baud_rate:%d, tclkdiv:%d, rclkdiv:%d\n",
144 __func__, sclk, baud_rate, tclkdiv, rclkdiv);
145
146 return 0;
147 }
148
149 static irqreturn_t sport_uart_rx_irq(int irq, void *dev_id)
150 {
151 struct sport_uart_port *up = dev_id;
152 struct tty_port *port = &up->port.state->port;
153 unsigned int ch;
154
155 spin_lock(&up->port.lock);
156
157 while (SPORT_GET_STAT(up) & RXNE) {
158 ch = rx_one_byte(up);
159 up->port.icount.rx++;
160
161 if (!uart_handle_sysrq_char(&up->port, ch))
162 tty_insert_flip_char(port, ch, TTY_NORMAL);
163 }
164
165 spin_unlock(&up->port.lock);
166
167 /* XXX this won't deadlock with lowlat? */
168 tty_flip_buffer_push(port);
169
170 return IRQ_HANDLED;
171 }
172
173 static irqreturn_t sport_uart_tx_irq(int irq, void *dev_id)
174 {
175 struct sport_uart_port *up = dev_id;
176
177 spin_lock(&up->port.lock);
178 sport_uart_tx_chars(up);
179 spin_unlock(&up->port.lock);
180
181 return IRQ_HANDLED;
182 }
183
184 static irqreturn_t sport_uart_err_irq(int irq, void *dev_id)
185 {
186 struct sport_uart_port *up = dev_id;
187 unsigned int stat = SPORT_GET_STAT(up);
188
189 spin_lock(&up->port.lock);
190
191 /* Overflow in RX FIFO */
192 if (stat & ROVF) {
193 up->port.icount.overrun++;
194 tty_insert_flip_char(&up->port.state->port, 0, TTY_OVERRUN);
195 SPORT_PUT_STAT(up, ROVF); /* Clear ROVF bit */
196 }
197 /* These should not happen */
198 if (stat & (TOVF | TUVF | RUVF)) {
199 pr_err("SPORT Error:%s %s %s\n",
200 (stat & TOVF) ? "TX overflow" : "",
201 (stat & TUVF) ? "TX underflow" : "",
202 (stat & RUVF) ? "RX underflow" : "");
203 SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
204 SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) & ~RSPEN);
205 }
206 SSYNC();
207
208 spin_unlock(&up->port.lock);
209 /* XXX we don't push the overrun bit to TTY? */
210
211 return IRQ_HANDLED;
212 }
213
214 #ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
215 static unsigned int sport_get_mctrl(struct uart_port *port)
216 {
217 struct sport_uart_port *up = (struct sport_uart_port *)port;
218 if (up->cts_pin < 0)
219 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
220
221 /* CTS PIN is negative assertive. */
222 if (SPORT_UART_GET_CTS(up))
223 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
224 else
225 return TIOCM_DSR | TIOCM_CAR;
226 }
227
228 static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)
229 {
230 struct sport_uart_port *up = (struct sport_uart_port *)port;
231 if (up->rts_pin < 0)
232 return;
233
234 /* RTS PIN is negative assertive. */
235 if (mctrl & TIOCM_RTS)
236 SPORT_UART_ENABLE_RTS(up);
237 else
238 SPORT_UART_DISABLE_RTS(up);
239 }
240
241 /*
242 * Handle any change of modem status signal.
243 */
244 static irqreturn_t sport_mctrl_cts_int(int irq, void *dev_id)
245 {
246 struct sport_uart_port *up = (struct sport_uart_port *)dev_id;
247 unsigned int status;
248
249 status = sport_get_mctrl(&up->port);
250 uart_handle_cts_change(&up->port, status & TIOCM_CTS);
251
252 return IRQ_HANDLED;
253 }
254 #else
255 static unsigned int sport_get_mctrl(struct uart_port *port)
256 {
257 pr_debug("%s enter\n", __func__);
258 return TIOCM_CTS | TIOCM_CD | TIOCM_DSR;
259 }
260
261 static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)
262 {
263 pr_debug("%s enter\n", __func__);
264 }
265 #endif
266
267 /* Reqeust IRQ, Setup clock */
268 static int sport_startup(struct uart_port *port)
269 {
270 struct sport_uart_port *up = (struct sport_uart_port *)port;
271 int ret;
272
273 pr_debug("%s enter\n", __func__);
274 ret = request_irq(up->port.irq, sport_uart_rx_irq, 0,
275 "SPORT_UART_RX", up);
276 if (ret) {
277 dev_err(port->dev, "unable to request SPORT RX interrupt\n");
278 return ret;
279 }
280
281 ret = request_irq(up->port.irq+1, sport_uart_tx_irq, 0,
282 "SPORT_UART_TX", up);
283 if (ret) {
284 dev_err(port->dev, "unable to request SPORT TX interrupt\n");
285 goto fail1;
286 }
287
288 ret = request_irq(up->err_irq, sport_uart_err_irq, 0,
289 "SPORT_UART_STATUS", up);
290 if (ret) {
291 dev_err(port->dev, "unable to request SPORT status interrupt\n");
292 goto fail2;
293 }
294
295 #ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
296 if (up->cts_pin >= 0) {
297 if (request_irq(gpio_to_irq(up->cts_pin),
298 sport_mctrl_cts_int,
299 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
300 0, "BFIN_SPORT_UART_CTS", up)) {
301 up->cts_pin = -1;
302 dev_info(port->dev, "Unable to attach BlackFin UART over SPORT CTS interrupt. So, disable it.\n");
303 }
304 }
305 if (up->rts_pin >= 0) {
306 if (gpio_request(up->rts_pin, DRV_NAME)) {
307 dev_info(port->dev, "fail to request RTS PIN at GPIO_%d\n", up->rts_pin);
308 up->rts_pin = -1;
309 } else
310 gpio_direction_output(up->rts_pin, 0);
311 }
312 #endif
313
314 return 0;
315 fail2:
316 free_irq(up->port.irq+1, up);
317 fail1:
318 free_irq(up->port.irq, up);
319
320 return ret;
321 }
322
323 /*
324 * sport_uart_tx_chars
325 *
326 * ret 1 means need to enable sport.
327 * ret 0 means do nothing.
328 */
329 static int sport_uart_tx_chars(struct sport_uart_port *up)
330 {
331 struct circ_buf *xmit = &up->port.state->xmit;
332
333 if (SPORT_GET_STAT(up) & TXF)
334 return 0;
335
336 if (up->port.x_char) {
337 tx_one_byte(up, up->port.x_char);
338 up->port.icount.tx++;
339 up->port.x_char = 0;
340 return 1;
341 }
342
343 if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
344 /* The waiting loop to stop SPORT TX from TX interrupt is
345 * too long. This may block SPORT RX interrupts and cause
346 * RX FIFO overflow. So, do stop sport TX only after the last
347 * char in TX FIFO is moved into the shift register.
348 */
349 if (SPORT_GET_STAT(up) & TXHRE)
350 sport_stop_tx(&up->port);
351 return 0;
352 }
353
354 while(!(SPORT_GET_STAT(up) & TXF) && !uart_circ_empty(xmit)) {
355 tx_one_byte(up, xmit->buf[xmit->tail]);
356 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
357 up->port.icount.tx++;
358 }
359
360 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
361 uart_write_wakeup(&up->port);
362
363 return 1;
364 }
365
366 static unsigned int sport_tx_empty(struct uart_port *port)
367 {
368 struct sport_uart_port *up = (struct sport_uart_port *)port;
369 unsigned int stat;
370
371 stat = SPORT_GET_STAT(up);
372 pr_debug("%s stat:%04x\n", __func__, stat);
373 if (stat & TXHRE) {
374 return TIOCSER_TEMT;
375 } else
376 return 0;
377 }
378
379 static void sport_stop_tx(struct uart_port *port)
380 {
381 struct sport_uart_port *up = (struct sport_uart_port *)port;
382
383 pr_debug("%s enter\n", __func__);
384
385 if (!(SPORT_GET_TCR1(up) & TSPEN))
386 return;
387
388 /* Although the hold register is empty, last byte is still in shift
389 * register and not sent out yet. So, put a dummy data into TX FIFO.
390 * Then, sport tx stops when last byte is shift out and the dummy
391 * data is moved into the shift register.
392 */
393 SPORT_PUT_TX(up, 0xffff);
394 while (!(SPORT_GET_STAT(up) & TXHRE))
395 cpu_relax();
396
397 SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
398 SSYNC();
399
400 return;
401 }
402
403 static void sport_start_tx(struct uart_port *port)
404 {
405 struct sport_uart_port *up = (struct sport_uart_port *)port;
406
407 pr_debug("%s enter\n", __func__);
408
409 /* Write data into SPORT FIFO before enable SPROT to transmit */
410 if (sport_uart_tx_chars(up)) {
411 /* Enable transmit, then an interrupt will generated */
412 SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
413 SSYNC();
414 }
415
416 pr_debug("%s exit\n", __func__);
417 }
418
419 static void sport_stop_rx(struct uart_port *port)
420 {
421 struct sport_uart_port *up = (struct sport_uart_port *)port;
422
423 pr_debug("%s enter\n", __func__);
424 /* Disable sport to stop rx */
425 SPORT_PUT_RCR1(up, (SPORT_GET_RCR1(up) & ~RSPEN));
426 SSYNC();
427 }
428
429 static void sport_enable_ms(struct uart_port *port)
430 {
431 pr_debug("%s enter\n", __func__);
432 }
433
434 static void sport_break_ctl(struct uart_port *port, int break_state)
435 {
436 pr_debug("%s enter\n", __func__);
437 }
438
439 static void sport_shutdown(struct uart_port *port)
440 {
441 struct sport_uart_port *up = (struct sport_uart_port *)port;
442
443 dev_dbg(port->dev, "%s enter\n", __func__);
444
445 /* Disable sport */
446 SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
447 SPORT_PUT_RCR1(up, (SPORT_GET_RCR1(up) & ~RSPEN));
448 SSYNC();
449
450 free_irq(up->port.irq, up);
451 free_irq(up->port.irq+1, up);
452 free_irq(up->err_irq, up);
453 #ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
454 if (up->cts_pin >= 0)
455 free_irq(gpio_to_irq(up->cts_pin), up);
456 if (up->rts_pin >= 0)
457 gpio_free(up->rts_pin);
458 #endif
459 }
460
461 static const char *sport_type(struct uart_port *port)
462 {
463 struct sport_uart_port *up = (struct sport_uart_port *)port;
464
465 pr_debug("%s enter\n", __func__);
466 return up->port.type == PORT_BFIN_SPORT ? "BFIN-SPORT-UART" : NULL;
467 }
468
469 static void sport_release_port(struct uart_port *port)
470 {
471 pr_debug("%s enter\n", __func__);
472 }
473
474 static int sport_request_port(struct uart_port *port)
475 {
476 pr_debug("%s enter\n", __func__);
477 return 0;
478 }
479
480 static void sport_config_port(struct uart_port *port, int flags)
481 {
482 struct sport_uart_port *up = (struct sport_uart_port *)port;
483
484 pr_debug("%s enter\n", __func__);
485 up->port.type = PORT_BFIN_SPORT;
486 }
487
488 static int sport_verify_port(struct uart_port *port, struct serial_struct *ser)
489 {
490 pr_debug("%s enter\n", __func__);
491 return 0;
492 }
493
494 static void sport_set_termios(struct uart_port *port,
495 struct ktermios *termios, struct ktermios *old)
496 {
497 struct sport_uart_port *up = (struct sport_uart_port *)port;
498 unsigned long flags;
499 int i;
500
501 pr_debug("%s enter, c_cflag:%08x\n", __func__, termios->c_cflag);
502
503 switch (termios->c_cflag & CSIZE) {
504 case CS8:
505 up->csize = 8;
506 break;
507 case CS7:
508 up->csize = 7;
509 break;
510 case CS6:
511 up->csize = 6;
512 break;
513 case CS5:
514 up->csize = 5;
515 break;
516 default:
517 pr_warning("requested word length not supported\n");
518 }
519
520 if (termios->c_cflag & CSTOPB) {
521 up->stopb = 1;
522 }
523 if (termios->c_cflag & PARENB) {
524 pr_warning("PAREN bits is not supported yet\n");
525 /* up->parib = 1; */
526 }
527
528 spin_lock_irqsave(&up->port.lock, flags);
529
530 port->read_status_mask = 0;
531
532 /*
533 * Characters to ignore
534 */
535 port->ignore_status_mask = 0;
536
537 /* RX extract mask */
538 up->rxmask = 0x01 | (((up->csize + up->stopb) * 2 - 1) << 0x8);
539 /* TX masks, 8 bit data and 1 bit stop for example:
540 * mask1 = b#0111111110
541 * mask2 = b#1000000000
542 */
543 for (i = 0, up->txmask1 = 0; i < up->csize; i++)
544 up->txmask1 |= (1<<i);
545 up->txmask2 = (1<<i);
546 if (up->stopb) {
547 ++i;
548 up->txmask2 |= (1<<i);
549 }
550 up->txmask1 <<= 1;
551 up->txmask2 <<= 1;
552 /* uart baud rate */
553 port->uartclk = uart_get_baud_rate(port, termios, old, 0, get_sclk()/16);
554
555 /* Disable UART */
556 SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
557 SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) & ~RSPEN);
558
559 sport_uart_setup(up, up->csize + up->stopb, port->uartclk);
560
561 /* driver TX line high after config, one dummy data is
562 * necessary to stop sport after shift one byte
563 */
564 SPORT_PUT_TX(up, 0xffff);
565 SPORT_PUT_TX(up, 0xffff);
566 SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
567 SSYNC();
568 while (!(SPORT_GET_STAT(up) & TXHRE))
569 cpu_relax();
570 SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
571 SSYNC();
572
573 /* Port speed changed, update the per-port timeout. */
574 uart_update_timeout(port, termios->c_cflag, port->uartclk);
575
576 /* Enable sport rx */
577 SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) | RSPEN);
578 SSYNC();
579
580 spin_unlock_irqrestore(&up->port.lock, flags);
581 }
582
583 struct uart_ops sport_uart_ops = {
584 .tx_empty = sport_tx_empty,
585 .set_mctrl = sport_set_mctrl,
586 .get_mctrl = sport_get_mctrl,
587 .stop_tx = sport_stop_tx,
588 .start_tx = sport_start_tx,
589 .stop_rx = sport_stop_rx,
590 .enable_ms = sport_enable_ms,
591 .break_ctl = sport_break_ctl,
592 .startup = sport_startup,
593 .shutdown = sport_shutdown,
594 .set_termios = sport_set_termios,
595 .type = sport_type,
596 .release_port = sport_release_port,
597 .request_port = sport_request_port,
598 .config_port = sport_config_port,
599 .verify_port = sport_verify_port,
600 };
601
602 #define BFIN_SPORT_UART_MAX_PORTS 4
603
604 static struct sport_uart_port *bfin_sport_uart_ports[BFIN_SPORT_UART_MAX_PORTS];
605
606 #ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
607 #define CLASS_BFIN_SPORT_CONSOLE "bfin-sport-console"
608
609 static int __init
610 sport_uart_console_setup(struct console *co, char *options)
611 {
612 struct sport_uart_port *up;
613 int baud = 57600;
614 int bits = 8;
615 int parity = 'n';
616 # ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
617 int flow = 'r';
618 # else
619 int flow = 'n';
620 # endif
621
622 /* Check whether an invalid uart number has been specified */
623 if (co->index < 0 || co->index >= BFIN_SPORT_UART_MAX_PORTS)
624 return -ENODEV;
625
626 up = bfin_sport_uart_ports[co->index];
627 if (!up)
628 return -ENODEV;
629
630 if (options)
631 uart_parse_options(options, &baud, &parity, &bits, &flow);
632
633 return uart_set_options(&up->port, co, baud, parity, bits, flow);
634 }
635
636 static void sport_uart_console_putchar(struct uart_port *port, int ch)
637 {
638 struct sport_uart_port *up = (struct sport_uart_port *)port;
639
640 while (SPORT_GET_STAT(up) & TXF)
641 barrier();
642
643 tx_one_byte(up, ch);
644 }
645
646 /*
647 * Interrupts are disabled on entering
648 */
649 static void
650 sport_uart_console_write(struct console *co, const char *s, unsigned int count)
651 {
652 struct sport_uart_port *up = bfin_sport_uart_ports[co->index];
653 unsigned long flags;
654
655 spin_lock_irqsave(&up->port.lock, flags);
656
657 if (SPORT_GET_TCR1(up) & TSPEN)
658 uart_console_write(&up->port, s, count, sport_uart_console_putchar);
659 else {
660 /* dummy data to start sport */
661 while (SPORT_GET_STAT(up) & TXF)
662 barrier();
663 SPORT_PUT_TX(up, 0xffff);
664 /* Enable transmit, then an interrupt will generated */
665 SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
666 SSYNC();
667
668 uart_console_write(&up->port, s, count, sport_uart_console_putchar);
669
670 /* Although the hold register is empty, last byte is still in shift
671 * register and not sent out yet. So, put a dummy data into TX FIFO.
672 * Then, sport tx stops when last byte is shift out and the dummy
673 * data is moved into the shift register.
674 */
675 while (SPORT_GET_STAT(up) & TXF)
676 barrier();
677 SPORT_PUT_TX(up, 0xffff);
678 while (!(SPORT_GET_STAT(up) & TXHRE))
679 barrier();
680
681 /* Stop sport tx transfer */
682 SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
683 SSYNC();
684 }
685
686 spin_unlock_irqrestore(&up->port.lock, flags);
687 }
688
689 static struct uart_driver sport_uart_reg;
690
691 static struct console sport_uart_console = {
692 .name = DEVICE_NAME,
693 .write = sport_uart_console_write,
694 .device = uart_console_device,
695 .setup = sport_uart_console_setup,
696 .flags = CON_PRINTBUFFER,
697 .index = -1,
698 .data = &sport_uart_reg,
699 };
700
701 #define SPORT_UART_CONSOLE (&sport_uart_console)
702 #else
703 #define SPORT_UART_CONSOLE NULL
704 #endif /* CONFIG_SERIAL_BFIN_SPORT_CONSOLE */
705
706
707 static struct uart_driver sport_uart_reg = {
708 .owner = THIS_MODULE,
709 .driver_name = DRV_NAME,
710 .dev_name = DEVICE_NAME,
711 .major = 204,
712 .minor = 84,
713 .nr = BFIN_SPORT_UART_MAX_PORTS,
714 .cons = SPORT_UART_CONSOLE,
715 };
716
717 #ifdef CONFIG_PM
718 static int sport_uart_suspend(struct device *dev)
719 {
720 struct sport_uart_port *sport = dev_get_drvdata(dev);
721
722 dev_dbg(dev, "%s enter\n", __func__);
723 if (sport)
724 uart_suspend_port(&sport_uart_reg, &sport->port);
725
726 return 0;
727 }
728
729 static int sport_uart_resume(struct device *dev)
730 {
731 struct sport_uart_port *sport = dev_get_drvdata(dev);
732
733 dev_dbg(dev, "%s enter\n", __func__);
734 if (sport)
735 uart_resume_port(&sport_uart_reg, &sport->port);
736
737 return 0;
738 }
739
740 static struct dev_pm_ops bfin_sport_uart_dev_pm_ops = {
741 .suspend = sport_uart_suspend,
742 .resume = sport_uart_resume,
743 };
744 #endif
745
746 static int sport_uart_probe(struct platform_device *pdev)
747 {
748 struct resource *res;
749 struct sport_uart_port *sport;
750 int ret = 0;
751
752 dev_dbg(&pdev->dev, "%s enter\n", __func__);
753
754 if (pdev->id < 0 || pdev->id >= BFIN_SPORT_UART_MAX_PORTS) {
755 dev_err(&pdev->dev, "Wrong sport uart platform device id.\n");
756 return -ENOENT;
757 }
758
759 if (bfin_sport_uart_ports[pdev->id] == NULL) {
760 bfin_sport_uart_ports[pdev->id] =
761 kzalloc(sizeof(struct sport_uart_port), GFP_KERNEL);
762 sport = bfin_sport_uart_ports[pdev->id];
763 if (!sport) {
764 dev_err(&pdev->dev,
765 "Fail to malloc sport_uart_port\n");
766 return -ENOMEM;
767 }
768
769 ret = peripheral_request_list(
770 (unsigned short *)dev_get_platdata(&pdev->dev),
771 DRV_NAME);
772 if (ret) {
773 dev_err(&pdev->dev,
774 "Fail to request SPORT peripherals\n");
775 goto out_error_free_mem;
776 }
777
778 spin_lock_init(&sport->port.lock);
779 sport->port.fifosize = SPORT_TX_FIFO_SIZE,
780 sport->port.ops = &sport_uart_ops;
781 sport->port.line = pdev->id;
782 sport->port.iotype = UPIO_MEM;
783 sport->port.flags = UPF_BOOT_AUTOCONF;
784
785 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
786 if (res == NULL) {
787 dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
788 ret = -ENOENT;
789 goto out_error_free_peripherals;
790 }
791
792 sport->port.membase = ioremap(res->start, resource_size(res));
793 if (!sport->port.membase) {
794 dev_err(&pdev->dev, "Cannot map sport IO\n");
795 ret = -ENXIO;
796 goto out_error_free_peripherals;
797 }
798 sport->port.mapbase = res->start;
799
800 sport->port.irq = platform_get_irq(pdev, 0);
801 if ((int)sport->port.irq < 0) {
802 dev_err(&pdev->dev, "No sport RX/TX IRQ specified\n");
803 ret = -ENOENT;
804 goto out_error_unmap;
805 }
806
807 sport->err_irq = platform_get_irq(pdev, 1);
808 if (sport->err_irq < 0) {
809 dev_err(&pdev->dev, "No sport status IRQ specified\n");
810 ret = -ENOENT;
811 goto out_error_unmap;
812 }
813 #ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
814 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
815 if (res == NULL)
816 sport->cts_pin = -1;
817 else {
818 sport->cts_pin = res->start;
819 sport->port.flags |= ASYNC_CTS_FLOW;
820 }
821
822 res = platform_get_resource(pdev, IORESOURCE_IO, 1);
823 if (res == NULL)
824 sport->rts_pin = -1;
825 else
826 sport->rts_pin = res->start;
827 #endif
828 }
829
830 #ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
831 if (!is_early_platform_device(pdev)) {
832 #endif
833 sport = bfin_sport_uart_ports[pdev->id];
834 sport->port.dev = &pdev->dev;
835 dev_set_drvdata(&pdev->dev, sport);
836 ret = uart_add_one_port(&sport_uart_reg, &sport->port);
837 #ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
838 }
839 #endif
840 if (!ret)
841 return 0;
842
843 if (sport) {
844 out_error_unmap:
845 iounmap(sport->port.membase);
846 out_error_free_peripherals:
847 peripheral_free_list(
848 (unsigned short *)dev_get_platdata(&pdev->dev));
849 out_error_free_mem:
850 kfree(sport);
851 bfin_sport_uart_ports[pdev->id] = NULL;
852 }
853
854 return ret;
855 }
856
857 static int sport_uart_remove(struct platform_device *pdev)
858 {
859 struct sport_uart_port *sport = platform_get_drvdata(pdev);
860
861 dev_dbg(&pdev->dev, "%s enter\n", __func__);
862 dev_set_drvdata(&pdev->dev, NULL);
863
864 if (sport) {
865 uart_remove_one_port(&sport_uart_reg, &sport->port);
866 iounmap(sport->port.membase);
867 peripheral_free_list(
868 (unsigned short *)dev_get_platdata(&pdev->dev));
869 kfree(sport);
870 bfin_sport_uart_ports[pdev->id] = NULL;
871 }
872
873 return 0;
874 }
875
876 static struct platform_driver sport_uart_driver = {
877 .probe = sport_uart_probe,
878 .remove = sport_uart_remove,
879 .driver = {
880 .name = DRV_NAME,
881 #ifdef CONFIG_PM
882 .pm = &bfin_sport_uart_dev_pm_ops,
883 #endif
884 },
885 };
886
887 #ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
888 static struct early_platform_driver early_sport_uart_driver __initdata = {
889 .class_str = CLASS_BFIN_SPORT_CONSOLE,
890 .pdrv = &sport_uart_driver,
891 .requested_id = EARLY_PLATFORM_ID_UNSET,
892 };
893
894 static int __init sport_uart_rs_console_init(void)
895 {
896 early_platform_driver_register(&early_sport_uart_driver, DRV_NAME);
897
898 early_platform_driver_probe(CLASS_BFIN_SPORT_CONSOLE,
899 BFIN_SPORT_UART_MAX_PORTS, 0);
900
901 register_console(&sport_uart_console);
902
903 return 0;
904 }
905 console_initcall(sport_uart_rs_console_init);
906 #endif
907
908 static int __init sport_uart_init(void)
909 {
910 int ret;
911
912 pr_info("Blackfin uart over sport driver\n");
913
914 ret = uart_register_driver(&sport_uart_reg);
915 if (ret) {
916 pr_err("failed to register %s:%d\n",
917 sport_uart_reg.driver_name, ret);
918 return ret;
919 }
920
921 ret = platform_driver_register(&sport_uart_driver);
922 if (ret) {
923 pr_err("failed to register sport uart driver:%d\n", ret);
924 uart_unregister_driver(&sport_uart_reg);
925 }
926
927 return ret;
928 }
929 module_init(sport_uart_init);
930
931 static void __exit sport_uart_exit(void)
932 {
933 platform_driver_unregister(&sport_uart_driver);
934 uart_unregister_driver(&sport_uart_reg);
935 }
936 module_exit(sport_uart_exit);
937
938 MODULE_AUTHOR("Sonic Zhang, Roy Huang");
939 MODULE_DESCRIPTION("Blackfin serial over SPORT driver");
940 MODULE_LICENSE("GPL");
This page took 0.153103 seconds and 5 git commands to generate.