Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

Linux/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(dev_get_platdata(&pdev->dev),
770                                                 DRV_NAME);
771                 if (ret) {
772                         dev_err(&pdev->dev,
773                                 "Fail to request SPORT peripherals\n");
774                         goto out_error_free_mem;
775                 }
776 
777                 spin_lock_init(&sport->port.lock);
778                 sport->port.fifosize  = SPORT_TX_FIFO_SIZE,
779                 sport->port.ops       = &sport_uart_ops;
780                 sport->port.line      = pdev->id;
781                 sport->port.iotype    = UPIO_MEM;
782                 sport->port.flags     = UPF_BOOT_AUTOCONF;
783 
784                 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
785                 if (res == NULL) {
786                         dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
787                         ret = -ENOENT;
788                         goto out_error_free_peripherals;
789                 }
790 
791                 sport->port.membase = ioremap(res->start, resource_size(res));
792                 if (!sport->port.membase) {
793                         dev_err(&pdev->dev, "Cannot map sport IO\n");
794                         ret = -ENXIO;
795                         goto out_error_free_peripherals;
796                 }
797                 sport->port.mapbase = res->start;
798 
799                 sport->port.irq = platform_get_irq(pdev, 0);
800                 if ((int)sport->port.irq < 0) {
801                         dev_err(&pdev->dev, "No sport RX/TX IRQ specified\n");
802                         ret = -ENOENT;
803                         goto out_error_unmap;
804                 }
805 
806                 sport->err_irq = platform_get_irq(pdev, 1);
807                 if (sport->err_irq < 0) {
808                         dev_err(&pdev->dev, "No sport status IRQ specified\n");
809                         ret = -ENOENT;
810                         goto out_error_unmap;
811                 }
812 #ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
813                 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
814                 if (res == NULL)
815                         sport->cts_pin = -1;
816                 else {
817                         sport->cts_pin = res->start;
818                         sport->port.flags |= ASYNC_CTS_FLOW;
819                 }
820 
821                 res = platform_get_resource(pdev, IORESOURCE_IO, 1);
822                 if (res == NULL)
823                         sport->rts_pin = -1;
824                 else
825                         sport->rts_pin = res->start;
826 #endif
827         }
828 
829 #ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
830         if (!is_early_platform_device(pdev)) {
831 #endif
832                 sport = bfin_sport_uart_ports[pdev->id];
833                 sport->port.dev = &pdev->dev;
834                 dev_set_drvdata(&pdev->dev, sport);
835                 ret = uart_add_one_port(&sport_uart_reg, &sport->port);
836 #ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
837         }
838 #endif
839         if (!ret)
840                 return 0;
841 
842         if (sport) {
843 out_error_unmap:
844                 iounmap(sport->port.membase);
845 out_error_free_peripherals:
846                 peripheral_free_list(dev_get_platdata(&pdev->dev));
847 out_error_free_mem:
848                 kfree(sport);
849                 bfin_sport_uart_ports[pdev->id] = NULL;
850         }
851 
852         return ret;
853 }
854 
855 static int sport_uart_remove(struct platform_device *pdev)
856 {
857         struct sport_uart_port *sport = platform_get_drvdata(pdev);
858 
859         dev_dbg(&pdev->dev, "%s enter\n", __func__);
860         dev_set_drvdata(&pdev->dev, NULL);
861 
862         if (sport) {
863                 uart_remove_one_port(&sport_uart_reg, &sport->port);
864                 iounmap(sport->port.membase);
865                 peripheral_free_list(dev_get_platdata(&pdev->dev));
866                 kfree(sport);
867                 bfin_sport_uart_ports[pdev->id] = NULL;
868         }
869 
870         return 0;
871 }
872 
873 static struct platform_driver sport_uart_driver = {
874         .probe          = sport_uart_probe,
875         .remove         = sport_uart_remove,
876         .driver         = {
877                 .name   = DRV_NAME,
878 #ifdef CONFIG_PM
879                 .pm     = &bfin_sport_uart_dev_pm_ops,
880 #endif
881         },
882 };
883 
884 #ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
885 static struct early_platform_driver early_sport_uart_driver __initdata = {
886         .class_str = CLASS_BFIN_SPORT_CONSOLE,
887         .pdrv = &sport_uart_driver,
888         .requested_id = EARLY_PLATFORM_ID_UNSET,
889 };
890 
891 static int __init sport_uart_rs_console_init(void)
892 {
893         early_platform_driver_register(&early_sport_uart_driver, DRV_NAME);
894 
895         early_platform_driver_probe(CLASS_BFIN_SPORT_CONSOLE,
896                 BFIN_SPORT_UART_MAX_PORTS, 0);
897 
898         register_console(&sport_uart_console);
899 
900         return 0;
901 }
902 console_initcall(sport_uart_rs_console_init);
903 #endif
904 
905 static int __init sport_uart_init(void)
906 {
907         int ret;
908 
909         pr_info("Blackfin uart over sport driver\n");
910 
911         ret = uart_register_driver(&sport_uart_reg);
912         if (ret) {
913                 pr_err("failed to register %s:%d\n",
914                                 sport_uart_reg.driver_name, ret);
915                 return ret;
916         }
917 
918         ret = platform_driver_register(&sport_uart_driver);
919         if (ret) {
920                 pr_err("failed to register sport uart driver:%d\n", ret);
921                 uart_unregister_driver(&sport_uart_reg);
922         }
923 
924         return ret;
925 }
926 module_init(sport_uart_init);
927 
928 static void __exit sport_uart_exit(void)
929 {
930         platform_driver_unregister(&sport_uart_driver);
931         uart_unregister_driver(&sport_uart_reg);
932 }
933 module_exit(sport_uart_exit);
934 
935 MODULE_AUTHOR("Sonic Zhang, Roy Huang");
936 MODULE_DESCRIPTION("Blackfin serial over SPORT driver");
937 MODULE_LICENSE("GPL");
938 

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