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