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Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
[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_struct *tty = up->port.state->port.tty;
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(tty, ch, TTY_NORMAL);
163 }
164 tty_flip_buffer_push(tty);
165
166 spin_unlock(&up->port.lock);
167
168 return IRQ_HANDLED;
169 }
170
171 static irqreturn_t sport_uart_tx_irq(int irq, void *dev_id)
172 {
173 struct sport_uart_port *up = dev_id;
174
175 spin_lock(&up->port.lock);
176 sport_uart_tx_chars(up);
177 spin_unlock(&up->port.lock);
178
179 return IRQ_HANDLED;
180 }
181
182 static irqreturn_t sport_uart_err_irq(int irq, void *dev_id)
183 {
184 struct sport_uart_port *up = dev_id;
185 struct tty_struct *tty = up->port.state->port.tty;
186 unsigned int stat = SPORT_GET_STAT(up);
187
188 spin_lock(&up->port.lock);
189
190 /* Overflow in RX FIFO */
191 if (stat & ROVF) {
192 up->port.icount.overrun++;
193 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
194 SPORT_PUT_STAT(up, ROVF); /* Clear ROVF bit */
195 }
196 /* These should not happen */
197 if (stat & (TOVF | TUVF | RUVF)) {
198 pr_err("SPORT Error:%s %s %s\n",
199 (stat & TOVF) ? "TX overflow" : "",
200 (stat & TUVF) ? "TX underflow" : "",
201 (stat & RUVF) ? "RX underflow" : "");
202 SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
203 SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) & ~RSPEN);
204 }
205 SSYNC();
206
207 spin_unlock(&up->port.lock);
208 return IRQ_HANDLED;
209 }
210
211 #ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
212 static unsigned int sport_get_mctrl(struct uart_port *port)
213 {
214 struct sport_uart_port *up = (struct sport_uart_port *)port;
215 if (up->cts_pin < 0)
216 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
217
218 /* CTS PIN is negative assertive. */
219 if (SPORT_UART_GET_CTS(up))
220 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
221 else
222 return TIOCM_DSR | TIOCM_CAR;
223 }
224
225 static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)
226 {
227 struct sport_uart_port *up = (struct sport_uart_port *)port;
228 if (up->rts_pin < 0)
229 return;
230
231 /* RTS PIN is negative assertive. */
232 if (mctrl & TIOCM_RTS)
233 SPORT_UART_ENABLE_RTS(up);
234 else
235 SPORT_UART_DISABLE_RTS(up);
236 }
237
238 /*
239 * Handle any change of modem status signal.
240 */
241 static irqreturn_t sport_mctrl_cts_int(int irq, void *dev_id)
242 {
243 struct sport_uart_port *up = (struct sport_uart_port *)dev_id;
244 unsigned int status;
245
246 status = sport_get_mctrl(&up->port);
247 uart_handle_cts_change(&up->port, status & TIOCM_CTS);
248
249 return IRQ_HANDLED;
250 }
251 #else
252 static unsigned int sport_get_mctrl(struct uart_port *port)
253 {
254 pr_debug("%s enter\n", __func__);
255 return TIOCM_CTS | TIOCM_CD | TIOCM_DSR;
256 }
257
258 static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)
259 {
260 pr_debug("%s enter\n", __func__);
261 }
262 #endif
263
264 /* Reqeust IRQ, Setup clock */
265 static int sport_startup(struct uart_port *port)
266 {
267 struct sport_uart_port *up = (struct sport_uart_port *)port;
268 int ret;
269
270 pr_debug("%s enter\n", __func__);
271 ret = request_irq(up->port.irq, sport_uart_rx_irq, 0,
272 "SPORT_UART_RX", up);
273 if (ret) {
274 dev_err(port->dev, "unable to request SPORT RX interrupt\n");
275 return ret;
276 }
277
278 ret = request_irq(up->port.irq+1, sport_uart_tx_irq, 0,
279 "SPORT_UART_TX", up);
280 if (ret) {
281 dev_err(port->dev, "unable to request SPORT TX interrupt\n");
282 goto fail1;
283 }
284
285 ret = request_irq(up->err_irq, sport_uart_err_irq, 0,
286 "SPORT_UART_STATUS", up);
287 if (ret) {
288 dev_err(port->dev, "unable to request SPORT status interrupt\n");
289 goto fail2;
290 }
291
292 #ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
293 if (up->cts_pin >= 0) {
294 if (request_irq(gpio_to_irq(up->cts_pin),
295 sport_mctrl_cts_int,
296 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
297 0, "BFIN_SPORT_UART_CTS", up)) {
298 up->cts_pin = -1;
299 dev_info(port->dev, "Unable to attach BlackFin UART over SPORT CTS interrupt. So, disable it.\n");
300 }
301 }
302 if (up->rts_pin >= 0) {
303 if (gpio_request(up->rts_pin, DRV_NAME)) {
304 dev_info(port->dev, "fail to request RTS PIN at GPIO_%d\n", up->rts_pin);
305 up->rts_pin = -1;
306 } else
307 gpio_direction_output(up->rts_pin, 0);
308 }
309 #endif
310
311 return 0;
312 fail2:
313 free_irq(up->port.irq+1, up);
314 fail1:
315 free_irq(up->port.irq, up);
316
317 return ret;
318 }
319
320 /*
321 * sport_uart_tx_chars
322 *
323 * ret 1 means need to enable sport.
324 * ret 0 means do nothing.
325 */
326 static int sport_uart_tx_chars(struct sport_uart_port *up)
327 {
328 struct circ_buf *xmit = &up->port.state->xmit;
329
330 if (SPORT_GET_STAT(up) & TXF)
331 return 0;
332
333 if (up->port.x_char) {
334 tx_one_byte(up, up->port.x_char);
335 up->port.icount.tx++;
336 up->port.x_char = 0;
337 return 1;
338 }
339
340 if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
341 /* The waiting loop to stop SPORT TX from TX interrupt is
342 * too long. This may block SPORT RX interrupts and cause
343 * RX FIFO overflow. So, do stop sport TX only after the last
344 * char in TX FIFO is moved into the shift register.
345 */
346 if (SPORT_GET_STAT(up) & TXHRE)
347 sport_stop_tx(&up->port);
348 return 0;
349 }
350
351 while(!(SPORT_GET_STAT(up) & TXF) && !uart_circ_empty(xmit)) {
352 tx_one_byte(up, xmit->buf[xmit->tail]);
353 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
354 up->port.icount.tx++;
355 }
356
357 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
358 uart_write_wakeup(&up->port);
359
360 return 1;
361 }
362
363 static unsigned int sport_tx_empty(struct uart_port *port)
364 {
365 struct sport_uart_port *up = (struct sport_uart_port *)port;
366 unsigned int stat;
367
368 stat = SPORT_GET_STAT(up);
369 pr_debug("%s stat:%04x\n", __func__, stat);
370 if (stat & TXHRE) {
371 return TIOCSER_TEMT;
372 } else
373 return 0;
374 }
375
376 static void sport_stop_tx(struct uart_port *port)
377 {
378 struct sport_uart_port *up = (struct sport_uart_port *)port;
379
380 pr_debug("%s enter\n", __func__);
381
382 if (!(SPORT_GET_TCR1(up) & TSPEN))
383 return;
384
385 /* Although the hold register is empty, last byte is still in shift
386 * register and not sent out yet. So, put a dummy data into TX FIFO.
387 * Then, sport tx stops when last byte is shift out and the dummy
388 * data is moved into the shift register.
389 */
390 SPORT_PUT_TX(up, 0xffff);
391 while (!(SPORT_GET_STAT(up) & TXHRE))
392 cpu_relax();
393
394 SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
395 SSYNC();
396
397 return;
398 }
399
400 static void sport_start_tx(struct uart_port *port)
401 {
402 struct sport_uart_port *up = (struct sport_uart_port *)port;
403
404 pr_debug("%s enter\n", __func__);
405
406 /* Write data into SPORT FIFO before enable SPROT to transmit */
407 if (sport_uart_tx_chars(up)) {
408 /* Enable transmit, then an interrupt will generated */
409 SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
410 SSYNC();
411 }
412
413 pr_debug("%s exit\n", __func__);
414 }
415
416 static void sport_stop_rx(struct uart_port *port)
417 {
418 struct sport_uart_port *up = (struct sport_uart_port *)port;
419
420 pr_debug("%s enter\n", __func__);
421 /* Disable sport to stop rx */
422 SPORT_PUT_RCR1(up, (SPORT_GET_RCR1(up) & ~RSPEN));
423 SSYNC();
424 }
425
426 static void sport_enable_ms(struct uart_port *port)
427 {
428 pr_debug("%s enter\n", __func__);
429 }
430
431 static void sport_break_ctl(struct uart_port *port, int break_state)
432 {
433 pr_debug("%s enter\n", __func__);
434 }
435
436 static void sport_shutdown(struct uart_port *port)
437 {
438 struct sport_uart_port *up = (struct sport_uart_port *)port;
439
440 dev_dbg(port->dev, "%s enter\n", __func__);
441
442 /* Disable sport */
443 SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
444 SPORT_PUT_RCR1(up, (SPORT_GET_RCR1(up) & ~RSPEN));
445 SSYNC();
446
447 free_irq(up->port.irq, up);
448 free_irq(up->port.irq+1, up);
449 free_irq(up->err_irq, up);
450 #ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
451 if (up->cts_pin >= 0)
452 free_irq(gpio_to_irq(up->cts_pin), up);
453 if (up->rts_pin >= 0)
454 gpio_free(up->rts_pin);
455 #endif
456 }
457
458 static const char *sport_type(struct uart_port *port)
459 {
460 struct sport_uart_port *up = (struct sport_uart_port *)port;
461
462 pr_debug("%s enter\n", __func__);
463 return up->port.type == PORT_BFIN_SPORT ? "BFIN-SPORT-UART" : NULL;
464 }
465
466 static void sport_release_port(struct uart_port *port)
467 {
468 pr_debug("%s enter\n", __func__);
469 }
470
471 static int sport_request_port(struct uart_port *port)
472 {
473 pr_debug("%s enter\n", __func__);
474 return 0;
475 }
476
477 static void sport_config_port(struct uart_port *port, int flags)
478 {
479 struct sport_uart_port *up = (struct sport_uart_port *)port;
480
481 pr_debug("%s enter\n", __func__);
482 up->port.type = PORT_BFIN_SPORT;
483 }
484
485 static int sport_verify_port(struct uart_port *port, struct serial_struct *ser)
486 {
487 pr_debug("%s enter\n", __func__);
488 return 0;
489 }
490
491 static void sport_set_termios(struct uart_port *port,
492 struct ktermios *termios, struct ktermios *old)
493 {
494 struct sport_uart_port *up = (struct sport_uart_port *)port;
495 unsigned long flags;
496 int i;
497
498 pr_debug("%s enter, c_cflag:%08x\n", __func__, termios->c_cflag);
499
500 switch (termios->c_cflag & CSIZE) {
501 case CS8:
502 up->csize = 8;
503 break;
504 case CS7:
505 up->csize = 7;
506 break;
507 case CS6:
508 up->csize = 6;
509 break;
510 case CS5:
511 up->csize = 5;
512 break;
513 default:
514 pr_warning("requested word length not supported\n");
515 }
516
517 if (termios->c_cflag & CSTOPB) {
518 up->stopb = 1;
519 }
520 if (termios->c_cflag & PARENB) {
521 pr_warning("PAREN bits is not supported yet\n");
522 /* up->parib = 1; */
523 }
524
525 spin_lock_irqsave(&up->port.lock, flags);
526
527 port->read_status_mask = 0;
528
529 /*
530 * Characters to ignore
531 */
532 port->ignore_status_mask = 0;
533
534 /* RX extract mask */
535 up->rxmask = 0x01 | (((up->csize + up->stopb) * 2 - 1) << 0x8);
536 /* TX masks, 8 bit data and 1 bit stop for example:
537 * mask1 = b#0111111110
538 * mask2 = b#1000000000
539 */
540 for (i = 0, up->txmask1 = 0; i < up->csize; i++)
541 up->txmask1 |= (1<<i);
542 up->txmask2 = (1<<i);
543 if (up->stopb) {
544 ++i;
545 up->txmask2 |= (1<<i);
546 }
547 up->txmask1 <<= 1;
548 up->txmask2 <<= 1;
549 /* uart baud rate */
550 port->uartclk = uart_get_baud_rate(port, termios, old, 0, get_sclk()/16);
551
552 /* Disable UART */
553 SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
554 SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) & ~RSPEN);
555
556 sport_uart_setup(up, up->csize + up->stopb, port->uartclk);
557
558 /* driver TX line high after config, one dummy data is
559 * necessary to stop sport after shift one byte
560 */
561 SPORT_PUT_TX(up, 0xffff);
562 SPORT_PUT_TX(up, 0xffff);
563 SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
564 SSYNC();
565 while (!(SPORT_GET_STAT(up) & TXHRE))
566 cpu_relax();
567 SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
568 SSYNC();
569
570 /* Port speed changed, update the per-port timeout. */
571 uart_update_timeout(port, termios->c_cflag, port->uartclk);
572
573 /* Enable sport rx */
574 SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) | RSPEN);
575 SSYNC();
576
577 spin_unlock_irqrestore(&up->port.lock, flags);
578 }
579
580 struct uart_ops sport_uart_ops = {
581 .tx_empty = sport_tx_empty,
582 .set_mctrl = sport_set_mctrl,
583 .get_mctrl = sport_get_mctrl,
584 .stop_tx = sport_stop_tx,
585 .start_tx = sport_start_tx,
586 .stop_rx = sport_stop_rx,
587 .enable_ms = sport_enable_ms,
588 .break_ctl = sport_break_ctl,
589 .startup = sport_startup,
590 .shutdown = sport_shutdown,
591 .set_termios = sport_set_termios,
592 .type = sport_type,
593 .release_port = sport_release_port,
594 .request_port = sport_request_port,
595 .config_port = sport_config_port,
596 .verify_port = sport_verify_port,
597 };
598
599 #define BFIN_SPORT_UART_MAX_PORTS 4
600
601 static struct sport_uart_port *bfin_sport_uart_ports[BFIN_SPORT_UART_MAX_PORTS];
602
603 #ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
604 #define CLASS_BFIN_SPORT_CONSOLE "bfin-sport-console"
605
606 static int __init
607 sport_uart_console_setup(struct console *co, char *options)
608 {
609 struct sport_uart_port *up;
610 int baud = 57600;
611 int bits = 8;
612 int parity = 'n';
613 # ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
614 int flow = 'r';
615 # else
616 int flow = 'n';
617 # endif
618
619 /* Check whether an invalid uart number has been specified */
620 if (co->index < 0 || co->index >= BFIN_SPORT_UART_MAX_PORTS)
621 return -ENODEV;
622
623 up = bfin_sport_uart_ports[co->index];
624 if (!up)
625 return -ENODEV;
626
627 if (options)
628 uart_parse_options(options, &baud, &parity, &bits, &flow);
629
630 return uart_set_options(&up->port, co, baud, parity, bits, flow);
631 }
632
633 static void sport_uart_console_putchar(struct uart_port *port, int ch)
634 {
635 struct sport_uart_port *up = (struct sport_uart_port *)port;
636
637 while (SPORT_GET_STAT(up) & TXF)
638 barrier();
639
640 tx_one_byte(up, ch);
641 }
642
643 /*
644 * Interrupts are disabled on entering
645 */
646 static void
647 sport_uart_console_write(struct console *co, const char *s, unsigned int count)
648 {
649 struct sport_uart_port *up = bfin_sport_uart_ports[co->index];
650 unsigned long flags;
651
652 spin_lock_irqsave(&up->port.lock, flags);
653
654 if (SPORT_GET_TCR1(up) & TSPEN)
655 uart_console_write(&up->port, s, count, sport_uart_console_putchar);
656 else {
657 /* dummy data to start sport */
658 while (SPORT_GET_STAT(up) & TXF)
659 barrier();
660 SPORT_PUT_TX(up, 0xffff);
661 /* Enable transmit, then an interrupt will generated */
662 SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
663 SSYNC();
664
665 uart_console_write(&up->port, s, count, sport_uart_console_putchar);
666
667 /* Although the hold register is empty, last byte is still in shift
668 * register and not sent out yet. So, put a dummy data into TX FIFO.
669 * Then, sport tx stops when last byte is shift out and the dummy
670 * data is moved into the shift register.
671 */
672 while (SPORT_GET_STAT(up) & TXF)
673 barrier();
674 SPORT_PUT_TX(up, 0xffff);
675 while (!(SPORT_GET_STAT(up) & TXHRE))
676 barrier();
677
678 /* Stop sport tx transfer */
679 SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
680 SSYNC();
681 }
682
683 spin_unlock_irqrestore(&up->port.lock, flags);
684 }
685
686 static struct uart_driver sport_uart_reg;
687
688 static struct console sport_uart_console = {
689 .name = DEVICE_NAME,
690 .write = sport_uart_console_write,
691 .device = uart_console_device,
692 .setup = sport_uart_console_setup,
693 .flags = CON_PRINTBUFFER,
694 .index = -1,
695 .data = &sport_uart_reg,
696 };
697
698 #define SPORT_UART_CONSOLE (&sport_uart_console)
699 #else
700 #define SPORT_UART_CONSOLE NULL
701 #endif /* CONFIG_SERIAL_BFIN_SPORT_CONSOLE */
702
703
704 static struct uart_driver sport_uart_reg = {
705 .owner = THIS_MODULE,
706 .driver_name = DRV_NAME,
707 .dev_name = DEVICE_NAME,
708 .major = 204,
709 .minor = 84,
710 .nr = BFIN_SPORT_UART_MAX_PORTS,
711 .cons = SPORT_UART_CONSOLE,
712 };
713
714 #ifdef CONFIG_PM
715 static int sport_uart_suspend(struct device *dev)
716 {
717 struct sport_uart_port *sport = dev_get_drvdata(dev);
718
719 dev_dbg(dev, "%s enter\n", __func__);
720 if (sport)
721 uart_suspend_port(&sport_uart_reg, &sport->port);
722
723 return 0;
724 }
725
726 static int sport_uart_resume(struct device *dev)
727 {
728 struct sport_uart_port *sport = dev_get_drvdata(dev);
729
730 dev_dbg(dev, "%s enter\n", __func__);
731 if (sport)
732 uart_resume_port(&sport_uart_reg, &sport->port);
733
734 return 0;
735 }
736
737 static struct dev_pm_ops bfin_sport_uart_dev_pm_ops = {
738 .suspend = sport_uart_suspend,
739 .resume = sport_uart_resume,
740 };
741 #endif
742
743 static int sport_uart_probe(struct platform_device *pdev)
744 {
745 struct resource *res;
746 struct sport_uart_port *sport;
747 int ret = 0;
748
749 dev_dbg(&pdev->dev, "%s enter\n", __func__);
750
751 if (pdev->id < 0 || pdev->id >= BFIN_SPORT_UART_MAX_PORTS) {
752 dev_err(&pdev->dev, "Wrong sport uart platform device id.\n");
753 return -ENOENT;
754 }
755
756 if (bfin_sport_uart_ports[pdev->id] == NULL) {
757 bfin_sport_uart_ports[pdev->id] =
758 kzalloc(sizeof(struct sport_uart_port), GFP_KERNEL);
759 sport = bfin_sport_uart_ports[pdev->id];
760 if (!sport) {
761 dev_err(&pdev->dev,
762 "Fail to malloc sport_uart_port\n");
763 return -ENOMEM;
764 }
765
766 ret = peripheral_request_list(
767 (unsigned short *)pdev->dev.platform_data, DRV_NAME);
768 if (ret) {
769 dev_err(&pdev->dev,
770 "Fail to request SPORT peripherals\n");
771 goto out_error_free_mem;
772 }
773
774 spin_lock_init(&sport->port.lock);
775 sport->port.fifosize = SPORT_TX_FIFO_SIZE,
776 sport->port.ops = &sport_uart_ops;
777 sport->port.line = pdev->id;
778 sport->port.iotype = UPIO_MEM;
779 sport->port.flags = UPF_BOOT_AUTOCONF;
780
781 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
782 if (res == NULL) {
783 dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
784 ret = -ENOENT;
785 goto out_error_free_peripherals;
786 }
787
788 sport->port.membase = ioremap(res->start, resource_size(res));
789 if (!sport->port.membase) {
790 dev_err(&pdev->dev, "Cannot map sport IO\n");
791 ret = -ENXIO;
792 goto out_error_free_peripherals;
793 }
794 sport->port.mapbase = res->start;
795
796 sport->port.irq = platform_get_irq(pdev, 0);
797 if ((int)sport->port.irq < 0) {
798 dev_err(&pdev->dev, "No sport RX/TX IRQ specified\n");
799 ret = -ENOENT;
800 goto out_error_unmap;
801 }
802
803 sport->err_irq = platform_get_irq(pdev, 1);
804 if (sport->err_irq < 0) {
805 dev_err(&pdev->dev, "No sport status IRQ specified\n");
806 ret = -ENOENT;
807 goto out_error_unmap;
808 }
809 #ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
810 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
811 if (res == NULL)
812 sport->cts_pin = -1;
813 else {
814 sport->cts_pin = res->start;
815 sport->port.flags |= ASYNC_CTS_FLOW;
816 }
817
818 res = platform_get_resource(pdev, IORESOURCE_IO, 1);
819 if (res == NULL)
820 sport->rts_pin = -1;
821 else
822 sport->rts_pin = res->start;
823 #endif
824 }
825
826 #ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
827 if (!is_early_platform_device(pdev)) {
828 #endif
829 sport = bfin_sport_uart_ports[pdev->id];
830 sport->port.dev = &pdev->dev;
831 dev_set_drvdata(&pdev->dev, sport);
832 ret = uart_add_one_port(&sport_uart_reg, &sport->port);
833 #ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
834 }
835 #endif
836 if (!ret)
837 return 0;
838
839 if (sport) {
840 out_error_unmap:
841 iounmap(sport->port.membase);
842 out_error_free_peripherals:
843 peripheral_free_list(
844 (unsigned short *)pdev->dev.platform_data);
845 out_error_free_mem:
846 kfree(sport);
847 bfin_sport_uart_ports[pdev->id] = NULL;
848 }
849
850 return ret;
851 }
852
853 static int sport_uart_remove(struct platform_device *pdev)
854 {
855 struct sport_uart_port *sport = platform_get_drvdata(pdev);
856
857 dev_dbg(&pdev->dev, "%s enter\n", __func__);
858 dev_set_drvdata(&pdev->dev, NULL);
859
860 if (sport) {
861 uart_remove_one_port(&sport_uart_reg, &sport->port);
862 iounmap(sport->port.membase);
863 peripheral_free_list(
864 (unsigned short *)pdev->dev.platform_data);
865 kfree(sport);
866 bfin_sport_uart_ports[pdev->id] = NULL;
867 }
868
869 return 0;
870 }
871
872 static struct platform_driver sport_uart_driver = {
873 .probe = sport_uart_probe,
874 .remove = sport_uart_remove,
875 .driver = {
876 .name = DRV_NAME,
877 #ifdef CONFIG_PM
878 .pm = &bfin_sport_uart_dev_pm_ops,
879 #endif
880 },
881 };
882
883 #ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
884 static __initdata struct early_platform_driver early_sport_uart_driver = {
885 .class_str = CLASS_BFIN_SPORT_CONSOLE,
886 .pdrv = &sport_uart_driver,
887 .requested_id = EARLY_PLATFORM_ID_UNSET,
888 };
889
890 static int __init sport_uart_rs_console_init(void)
891 {
892 early_platform_driver_register(&early_sport_uart_driver, DRV_NAME);
893
894 early_platform_driver_probe(CLASS_BFIN_SPORT_CONSOLE,
895 BFIN_SPORT_UART_MAX_PORTS, 0);
896
897 register_console(&sport_uart_console);
898
899 return 0;
900 }
901 console_initcall(sport_uart_rs_console_init);
902 #endif
903
904 static int __init sport_uart_init(void)
905 {
906 int ret;
907
908 pr_info("Blackfin uart over sport driver\n");
909
910 ret = uart_register_driver(&sport_uart_reg);
911 if (ret) {
912 pr_err("failed to register %s:%d\n",
913 sport_uart_reg.driver_name, ret);
914 return ret;
915 }
916
917 ret = platform_driver_register(&sport_uart_driver);
918 if (ret) {
919 pr_err("failed to register sport uart driver:%d\n", ret);
920 uart_unregister_driver(&sport_uart_reg);
921 }
922
923 return ret;
924 }
925 module_init(sport_uart_init);
926
927 static void __exit sport_uart_exit(void)
928 {
929 platform_driver_unregister(&sport_uart_driver);
930 uart_unregister_driver(&sport_uart_reg);
931 }
932 module_exit(sport_uart_exit);
933
934 MODULE_AUTHOR("Sonic Zhang, Roy Huang");
935 MODULE_DESCRIPTION("Blackfin serial over SPORT driver");
936 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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