Version:  2.0.40 2.2.26 2.4.37 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1

Linux/drivers/tty/serial/bcm63xx_uart.c

  1 /*
  2  * This file is subject to the terms and conditions of the GNU General Public
  3  * License.  See the file "COPYING" in the main directory of this archive
  4  * for more details.
  5  *
  6  * Derived from many drivers using generic_serial interface.
  7  *
  8  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
  9  *
 10  *  Serial driver for BCM63xx integrated UART.
 11  *
 12  * Hardware flow control was _not_ tested since I only have RX/TX on
 13  * my board.
 14  */
 15 
 16 #if defined(CONFIG_SERIAL_BCM63XX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
 17 #define SUPPORT_SYSRQ
 18 #endif
 19 
 20 #include <linux/kernel.h>
 21 #include <linux/platform_device.h>
 22 #include <linux/init.h>
 23 #include <linux/delay.h>
 24 #include <linux/module.h>
 25 #include <linux/console.h>
 26 #include <linux/clk.h>
 27 #include <linux/tty.h>
 28 #include <linux/tty_flip.h>
 29 #include <linux/sysrq.h>
 30 #include <linux/serial.h>
 31 #include <linux/serial_core.h>
 32 #include <linux/serial_bcm63xx.h>
 33 #include <linux/io.h>
 34 #include <linux/of.h>
 35 
 36 #define BCM63XX_NR_UARTS        2
 37 
 38 static struct uart_port ports[BCM63XX_NR_UARTS];
 39 
 40 /*
 41  * rx interrupt mask / stat
 42  *
 43  * mask:
 44  *  - rx fifo full
 45  *  - rx fifo above threshold
 46  *  - rx fifo not empty for too long
 47  */
 48 #define UART_RX_INT_MASK        (UART_IR_MASK(UART_IR_RXOVER) |         \
 49                                 UART_IR_MASK(UART_IR_RXTHRESH) |        \
 50                                 UART_IR_MASK(UART_IR_RXTIMEOUT))
 51 
 52 #define UART_RX_INT_STAT        (UART_IR_STAT(UART_IR_RXOVER) |         \
 53                                 UART_IR_STAT(UART_IR_RXTHRESH) |        \
 54                                 UART_IR_STAT(UART_IR_RXTIMEOUT))
 55 
 56 /*
 57  * tx interrupt mask / stat
 58  *
 59  * mask:
 60  * - tx fifo empty
 61  * - tx fifo below threshold
 62  */
 63 #define UART_TX_INT_MASK        (UART_IR_MASK(UART_IR_TXEMPTY) |        \
 64                                 UART_IR_MASK(UART_IR_TXTRESH))
 65 
 66 #define UART_TX_INT_STAT        (UART_IR_STAT(UART_IR_TXEMPTY) |        \
 67                                 UART_IR_STAT(UART_IR_TXTRESH))
 68 
 69 /*
 70  * external input interrupt
 71  *
 72  * mask: any edge on CTS, DCD
 73  */
 74 #define UART_EXTINP_INT_MASK    (UART_EXTINP_IRMASK(UART_EXTINP_IR_CTS) | \
 75                                  UART_EXTINP_IRMASK(UART_EXTINP_IR_DCD))
 76 
 77 /*
 78  * handy uart register accessor
 79  */
 80 static inline unsigned int bcm_uart_readl(struct uart_port *port,
 81                                          unsigned int offset)
 82 {
 83         return __raw_readl(port->membase + offset);
 84 }
 85 
 86 static inline void bcm_uart_writel(struct uart_port *port,
 87                                   unsigned int value, unsigned int offset)
 88 {
 89         __raw_writel(value, port->membase + offset);
 90 }
 91 
 92 /*
 93  * serial core request to check if uart tx fifo is empty
 94  */
 95 static unsigned int bcm_uart_tx_empty(struct uart_port *port)
 96 {
 97         unsigned int val;
 98 
 99         val = bcm_uart_readl(port, UART_IR_REG);
100         return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 1 : 0;
101 }
102 
103 /*
104  * serial core request to set RTS and DTR pin state and loopback mode
105  */
106 static void bcm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
107 {
108         unsigned int val;
109 
110         val = bcm_uart_readl(port, UART_MCTL_REG);
111         val &= ~(UART_MCTL_DTR_MASK | UART_MCTL_RTS_MASK);
112         /* invert of written value is reflected on the pin */
113         if (!(mctrl & TIOCM_DTR))
114                 val |= UART_MCTL_DTR_MASK;
115         if (!(mctrl & TIOCM_RTS))
116                 val |= UART_MCTL_RTS_MASK;
117         bcm_uart_writel(port, val, UART_MCTL_REG);
118 
119         val = bcm_uart_readl(port, UART_CTL_REG);
120         if (mctrl & TIOCM_LOOP)
121                 val |= UART_CTL_LOOPBACK_MASK;
122         else
123                 val &= ~UART_CTL_LOOPBACK_MASK;
124         bcm_uart_writel(port, val, UART_CTL_REG);
125 }
126 
127 /*
128  * serial core request to return RI, CTS, DCD and DSR pin state
129  */
130 static unsigned int bcm_uart_get_mctrl(struct uart_port *port)
131 {
132         unsigned int val, mctrl;
133 
134         mctrl = 0;
135         val = bcm_uart_readl(port, UART_EXTINP_REG);
136         if (val & UART_EXTINP_RI_MASK)
137                 mctrl |= TIOCM_RI;
138         if (val & UART_EXTINP_CTS_MASK)
139                 mctrl |= TIOCM_CTS;
140         if (val & UART_EXTINP_DCD_MASK)
141                 mctrl |= TIOCM_CD;
142         if (val & UART_EXTINP_DSR_MASK)
143                 mctrl |= TIOCM_DSR;
144         return mctrl;
145 }
146 
147 /*
148  * serial core request to disable tx ASAP (used for flow control)
149  */
150 static void bcm_uart_stop_tx(struct uart_port *port)
151 {
152         unsigned int val;
153 
154         val = bcm_uart_readl(port, UART_CTL_REG);
155         val &= ~(UART_CTL_TXEN_MASK);
156         bcm_uart_writel(port, val, UART_CTL_REG);
157 
158         val = bcm_uart_readl(port, UART_IR_REG);
159         val &= ~UART_TX_INT_MASK;
160         bcm_uart_writel(port, val, UART_IR_REG);
161 }
162 
163 /*
164  * serial core request to (re)enable tx
165  */
166 static void bcm_uart_start_tx(struct uart_port *port)
167 {
168         unsigned int val;
169 
170         val = bcm_uart_readl(port, UART_IR_REG);
171         val |= UART_TX_INT_MASK;
172         bcm_uart_writel(port, val, UART_IR_REG);
173 
174         val = bcm_uart_readl(port, UART_CTL_REG);
175         val |= UART_CTL_TXEN_MASK;
176         bcm_uart_writel(port, val, UART_CTL_REG);
177 }
178 
179 /*
180  * serial core request to stop rx, called before port shutdown
181  */
182 static void bcm_uart_stop_rx(struct uart_port *port)
183 {
184         unsigned int val;
185 
186         val = bcm_uart_readl(port, UART_IR_REG);
187         val &= ~UART_RX_INT_MASK;
188         bcm_uart_writel(port, val, UART_IR_REG);
189 }
190 
191 /*
192  * serial core request to enable modem status interrupt reporting
193  */
194 static void bcm_uart_enable_ms(struct uart_port *port)
195 {
196         unsigned int val;
197 
198         val = bcm_uart_readl(port, UART_IR_REG);
199         val |= UART_IR_MASK(UART_IR_EXTIP);
200         bcm_uart_writel(port, val, UART_IR_REG);
201 }
202 
203 /*
204  * serial core request to start/stop emitting break char
205  */
206 static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
207 {
208         unsigned long flags;
209         unsigned int val;
210 
211         spin_lock_irqsave(&port->lock, flags);
212 
213         val = bcm_uart_readl(port, UART_CTL_REG);
214         if (ctl)
215                 val |= UART_CTL_XMITBRK_MASK;
216         else
217                 val &= ~UART_CTL_XMITBRK_MASK;
218         bcm_uart_writel(port, val, UART_CTL_REG);
219 
220         spin_unlock_irqrestore(&port->lock, flags);
221 }
222 
223 /*
224  * return port type in string format
225  */
226 static const char *bcm_uart_type(struct uart_port *port)
227 {
228         return (port->type == PORT_BCM63XX) ? "bcm63xx_uart" : NULL;
229 }
230 
231 /*
232  * read all chars in rx fifo and send them to core
233  */
234 static void bcm_uart_do_rx(struct uart_port *port)
235 {
236         struct tty_port *tty_port = &port->state->port;
237         unsigned int max_count;
238 
239         /* limit number of char read in interrupt, should not be
240          * higher than fifo size anyway since we're much faster than
241          * serial port */
242         max_count = 32;
243         do {
244                 unsigned int iestat, c, cstat;
245                 char flag;
246 
247                 /* get overrun/fifo empty information from ier
248                  * register */
249                 iestat = bcm_uart_readl(port, UART_IR_REG);
250 
251                 if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
252                         unsigned int val;
253 
254                         /* fifo reset is required to clear
255                          * interrupt */
256                         val = bcm_uart_readl(port, UART_CTL_REG);
257                         val |= UART_CTL_RSTRXFIFO_MASK;
258                         bcm_uart_writel(port, val, UART_CTL_REG);
259 
260                         port->icount.overrun++;
261                         tty_insert_flip_char(tty_port, 0, TTY_OVERRUN);
262                 }
263 
264                 if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
265                         break;
266 
267                 cstat = c = bcm_uart_readl(port, UART_FIFO_REG);
268                 port->icount.rx++;
269                 flag = TTY_NORMAL;
270                 c &= 0xff;
271 
272                 if (unlikely((cstat & UART_FIFO_ANYERR_MASK))) {
273                         /* do stats first */
274                         if (cstat & UART_FIFO_BRKDET_MASK) {
275                                 port->icount.brk++;
276                                 if (uart_handle_break(port))
277                                         continue;
278                         }
279 
280                         if (cstat & UART_FIFO_PARERR_MASK)
281                                 port->icount.parity++;
282                         if (cstat & UART_FIFO_FRAMEERR_MASK)
283                                 port->icount.frame++;
284 
285                         /* update flag wrt read_status_mask */
286                         cstat &= port->read_status_mask;
287                         if (cstat & UART_FIFO_BRKDET_MASK)
288                                 flag = TTY_BREAK;
289                         if (cstat & UART_FIFO_FRAMEERR_MASK)
290                                 flag = TTY_FRAME;
291                         if (cstat & UART_FIFO_PARERR_MASK)
292                                 flag = TTY_PARITY;
293                 }
294 
295                 if (uart_handle_sysrq_char(port, c))
296                         continue;
297 
298 
299                 if ((cstat & port->ignore_status_mask) == 0)
300                         tty_insert_flip_char(tty_port, c, flag);
301 
302         } while (--max_count);
303 
304         spin_unlock(&port->lock);
305         tty_flip_buffer_push(tty_port);
306         spin_lock(&port->lock);
307 }
308 
309 /*
310  * fill tx fifo with chars to send, stop when fifo is about to be full
311  * or when all chars have been sent.
312  */
313 static void bcm_uart_do_tx(struct uart_port *port)
314 {
315         struct circ_buf *xmit;
316         unsigned int val, max_count;
317 
318         if (port->x_char) {
319                 bcm_uart_writel(port, port->x_char, UART_FIFO_REG);
320                 port->icount.tx++;
321                 port->x_char = 0;
322                 return;
323         }
324 
325         if (uart_tx_stopped(port)) {
326                 bcm_uart_stop_tx(port);
327                 return;
328         }
329 
330         xmit = &port->state->xmit;
331         if (uart_circ_empty(xmit))
332                 goto txq_empty;
333 
334         val = bcm_uart_readl(port, UART_MCTL_REG);
335         val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
336         max_count = port->fifosize - val;
337 
338         while (max_count--) {
339                 unsigned int c;
340 
341                 c = xmit->buf[xmit->tail];
342                 bcm_uart_writel(port, c, UART_FIFO_REG);
343                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
344                 port->icount.tx++;
345                 if (uart_circ_empty(xmit))
346                         break;
347         }
348 
349         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
350                 uart_write_wakeup(port);
351 
352         if (uart_circ_empty(xmit))
353                 goto txq_empty;
354         return;
355 
356 txq_empty:
357         /* nothing to send, disable transmit interrupt */
358         val = bcm_uart_readl(port, UART_IR_REG);
359         val &= ~UART_TX_INT_MASK;
360         bcm_uart_writel(port, val, UART_IR_REG);
361         return;
362 }
363 
364 /*
365  * process uart interrupt
366  */
367 static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
368 {
369         struct uart_port *port;
370         unsigned int irqstat;
371 
372         port = dev_id;
373         spin_lock(&port->lock);
374 
375         irqstat = bcm_uart_readl(port, UART_IR_REG);
376         if (irqstat & UART_RX_INT_STAT)
377                 bcm_uart_do_rx(port);
378 
379         if (irqstat & UART_TX_INT_STAT)
380                 bcm_uart_do_tx(port);
381 
382         if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) {
383                 unsigned int estat;
384 
385                 estat = bcm_uart_readl(port, UART_EXTINP_REG);
386                 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS))
387                         uart_handle_cts_change(port,
388                                                estat & UART_EXTINP_CTS_MASK);
389                 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD))
390                         uart_handle_dcd_change(port,
391                                                estat & UART_EXTINP_DCD_MASK);
392         }
393 
394         spin_unlock(&port->lock);
395         return IRQ_HANDLED;
396 }
397 
398 /*
399  * enable rx & tx operation on uart
400  */
401 static void bcm_uart_enable(struct uart_port *port)
402 {
403         unsigned int val;
404 
405         val = bcm_uart_readl(port, UART_CTL_REG);
406         val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
407         bcm_uart_writel(port, val, UART_CTL_REG);
408 }
409 
410 /*
411  * disable rx & tx operation on uart
412  */
413 static void bcm_uart_disable(struct uart_port *port)
414 {
415         unsigned int val;
416 
417         val = bcm_uart_readl(port, UART_CTL_REG);
418         val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
419                  UART_CTL_RXEN_MASK);
420         bcm_uart_writel(port, val, UART_CTL_REG);
421 }
422 
423 /*
424  * clear all unread data in rx fifo and unsent data in tx fifo
425  */
426 static void bcm_uart_flush(struct uart_port *port)
427 {
428         unsigned int val;
429 
430         /* empty rx and tx fifo */
431         val = bcm_uart_readl(port, UART_CTL_REG);
432         val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
433         bcm_uart_writel(port, val, UART_CTL_REG);
434 
435         /* read any pending char to make sure all irq status are
436          * cleared */
437         (void)bcm_uart_readl(port, UART_FIFO_REG);
438 }
439 
440 /*
441  * serial core request to initialize uart and start rx operation
442  */
443 static int bcm_uart_startup(struct uart_port *port)
444 {
445         unsigned int val;
446         int ret;
447 
448         /* mask all irq and flush port */
449         bcm_uart_disable(port);
450         bcm_uart_writel(port, 0, UART_IR_REG);
451         bcm_uart_flush(port);
452 
453         /* clear any pending external input interrupt */
454         (void)bcm_uart_readl(port, UART_EXTINP_REG);
455 
456         /* set rx/tx fifo thresh to fifo half size */
457         val = bcm_uart_readl(port, UART_MCTL_REG);
458         val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK);
459         val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT;
460         val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT;
461         bcm_uart_writel(port, val, UART_MCTL_REG);
462 
463         /* set rx fifo timeout to 1 char time */
464         val = bcm_uart_readl(port, UART_CTL_REG);
465         val &= ~UART_CTL_RXTMOUTCNT_MASK;
466         val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT;
467         bcm_uart_writel(port, val, UART_CTL_REG);
468 
469         /* report any edge on dcd and cts */
470         val = UART_EXTINP_INT_MASK;
471         val |= UART_EXTINP_DCD_NOSENSE_MASK;
472         val |= UART_EXTINP_CTS_NOSENSE_MASK;
473         bcm_uart_writel(port, val, UART_EXTINP_REG);
474 
475         /* register irq and enable rx interrupts */
476         ret = request_irq(port->irq, bcm_uart_interrupt, 0,
477                           bcm_uart_type(port), port);
478         if (ret)
479                 return ret;
480         bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);
481         bcm_uart_enable(port);
482         return 0;
483 }
484 
485 /*
486  * serial core request to flush & disable uart
487  */
488 static void bcm_uart_shutdown(struct uart_port *port)
489 {
490         unsigned long flags;
491 
492         spin_lock_irqsave(&port->lock, flags);
493         bcm_uart_writel(port, 0, UART_IR_REG);
494         spin_unlock_irqrestore(&port->lock, flags);
495 
496         bcm_uart_disable(port);
497         bcm_uart_flush(port);
498         free_irq(port->irq, port);
499 }
500 
501 /*
502  * serial core request to change current uart setting
503  */
504 static void bcm_uart_set_termios(struct uart_port *port,
505                                  struct ktermios *new,
506                                  struct ktermios *old)
507 {
508         unsigned int ctl, baud, quot, ier;
509         unsigned long flags;
510 
511         spin_lock_irqsave(&port->lock, flags);
512 
513         /* disable uart while changing speed */
514         bcm_uart_disable(port);
515         bcm_uart_flush(port);
516 
517         /* update Control register */
518         ctl = bcm_uart_readl(port, UART_CTL_REG);
519         ctl &= ~UART_CTL_BITSPERSYM_MASK;
520 
521         switch (new->c_cflag & CSIZE) {
522         case CS5:
523                 ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT);
524                 break;
525         case CS6:
526                 ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT);
527                 break;
528         case CS7:
529                 ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT);
530                 break;
531         default:
532                 ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT);
533                 break;
534         }
535 
536         ctl &= ~UART_CTL_STOPBITS_MASK;
537         if (new->c_cflag & CSTOPB)
538                 ctl |= UART_CTL_STOPBITS_2;
539         else
540                 ctl |= UART_CTL_STOPBITS_1;
541 
542         ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
543         if (new->c_cflag & PARENB)
544                 ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
545         ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
546         if (new->c_cflag & PARODD)
547                 ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
548         bcm_uart_writel(port, ctl, UART_CTL_REG);
549 
550         /* update Baudword register */
551         baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
552         quot = uart_get_divisor(port, baud) - 1;
553         bcm_uart_writel(port, quot, UART_BAUD_REG);
554 
555         /* update Interrupt register */
556         ier = bcm_uart_readl(port, UART_IR_REG);
557 
558         ier &= ~UART_IR_MASK(UART_IR_EXTIP);
559         if (UART_ENABLE_MS(port, new->c_cflag))
560                 ier |= UART_IR_MASK(UART_IR_EXTIP);
561 
562         bcm_uart_writel(port, ier, UART_IR_REG);
563 
564         /* update read/ignore mask */
565         port->read_status_mask = UART_FIFO_VALID_MASK;
566         if (new->c_iflag & INPCK) {
567                 port->read_status_mask |= UART_FIFO_FRAMEERR_MASK;
568                 port->read_status_mask |= UART_FIFO_PARERR_MASK;
569         }
570         if (new->c_iflag & (IGNBRK | BRKINT))
571                 port->read_status_mask |= UART_FIFO_BRKDET_MASK;
572 
573         port->ignore_status_mask = 0;
574         if (new->c_iflag & IGNPAR)
575                 port->ignore_status_mask |= UART_FIFO_PARERR_MASK;
576         if (new->c_iflag & IGNBRK)
577                 port->ignore_status_mask |= UART_FIFO_BRKDET_MASK;
578         if (!(new->c_cflag & CREAD))
579                 port->ignore_status_mask |= UART_FIFO_VALID_MASK;
580 
581         uart_update_timeout(port, new->c_cflag, baud);
582         bcm_uart_enable(port);
583         spin_unlock_irqrestore(&port->lock, flags);
584 }
585 
586 /*
587  * serial core request to claim uart iomem
588  */
589 static int bcm_uart_request_port(struct uart_port *port)
590 {
591         /* UARTs always present */
592         return 0;
593 }
594 
595 /*
596  * serial core request to release uart iomem
597  */
598 static void bcm_uart_release_port(struct uart_port *port)
599 {
600         /* Nothing to release ... */
601 }
602 
603 /*
604  * serial core request to do any port required autoconfiguration
605  */
606 static void bcm_uart_config_port(struct uart_port *port, int flags)
607 {
608         if (flags & UART_CONFIG_TYPE) {
609                 if (bcm_uart_request_port(port))
610                         return;
611                 port->type = PORT_BCM63XX;
612         }
613 }
614 
615 /*
616  * serial core request to check that port information in serinfo are
617  * suitable
618  */
619 static int bcm_uart_verify_port(struct uart_port *port,
620                                 struct serial_struct *serinfo)
621 {
622         if (port->type != PORT_BCM63XX)
623                 return -EINVAL;
624         if (port->irq != serinfo->irq)
625                 return -EINVAL;
626         if (port->iotype != serinfo->io_type)
627                 return -EINVAL;
628         if (port->mapbase != (unsigned long)serinfo->iomem_base)
629                 return -EINVAL;
630         return 0;
631 }
632 
633 /* serial core callbacks */
634 static struct uart_ops bcm_uart_ops = {
635         .tx_empty       = bcm_uart_tx_empty,
636         .get_mctrl      = bcm_uart_get_mctrl,
637         .set_mctrl      = bcm_uart_set_mctrl,
638         .start_tx       = bcm_uart_start_tx,
639         .stop_tx        = bcm_uart_stop_tx,
640         .stop_rx        = bcm_uart_stop_rx,
641         .enable_ms      = bcm_uart_enable_ms,
642         .break_ctl      = bcm_uart_break_ctl,
643         .startup        = bcm_uart_startup,
644         .shutdown       = bcm_uart_shutdown,
645         .set_termios    = bcm_uart_set_termios,
646         .type           = bcm_uart_type,
647         .release_port   = bcm_uart_release_port,
648         .request_port   = bcm_uart_request_port,
649         .config_port    = bcm_uart_config_port,
650         .verify_port    = bcm_uart_verify_port,
651 };
652 
653 
654 
655 #ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
656 static inline void wait_for_xmitr(struct uart_port *port)
657 {
658         unsigned int tmout;
659 
660         /* Wait up to 10ms for the character(s) to be sent. */
661         tmout = 10000;
662         while (--tmout) {
663                 unsigned int val;
664 
665                 val = bcm_uart_readl(port, UART_IR_REG);
666                 if (val & UART_IR_STAT(UART_IR_TXEMPTY))
667                         break;
668                 udelay(1);
669         }
670 
671         /* Wait up to 1s for flow control if necessary */
672         if (port->flags & UPF_CONS_FLOW) {
673                 tmout = 1000000;
674                 while (--tmout) {
675                         unsigned int val;
676 
677                         val = bcm_uart_readl(port, UART_EXTINP_REG);
678                         if (val & UART_EXTINP_CTS_MASK)
679                                 break;
680                         udelay(1);
681                 }
682         }
683 }
684 
685 /*
686  * output given char
687  */
688 static void bcm_console_putchar(struct uart_port *port, int ch)
689 {
690         wait_for_xmitr(port);
691         bcm_uart_writel(port, ch, UART_FIFO_REG);
692 }
693 
694 /*
695  * console core request to output given string
696  */
697 static void bcm_console_write(struct console *co, const char *s,
698                               unsigned int count)
699 {
700         struct uart_port *port;
701         unsigned long flags;
702         int locked;
703 
704         port = &ports[co->index];
705 
706         local_irq_save(flags);
707         if (port->sysrq) {
708                 /* bcm_uart_interrupt() already took the lock */
709                 locked = 0;
710         } else if (oops_in_progress) {
711                 locked = spin_trylock(&port->lock);
712         } else {
713                 spin_lock(&port->lock);
714                 locked = 1;
715         }
716 
717         /* call helper to deal with \r\n */
718         uart_console_write(port, s, count, bcm_console_putchar);
719 
720         /* and wait for char to be transmitted */
721         wait_for_xmitr(port);
722 
723         if (locked)
724                 spin_unlock(&port->lock);
725         local_irq_restore(flags);
726 }
727 
728 /*
729  * console core request to setup given console, find matching uart
730  * port and setup it.
731  */
732 static int bcm_console_setup(struct console *co, char *options)
733 {
734         struct uart_port *port;
735         int baud = 9600;
736         int bits = 8;
737         int parity = 'n';
738         int flow = 'n';
739 
740         if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
741                 return -EINVAL;
742         port = &ports[co->index];
743         if (!port->membase)
744                 return -ENODEV;
745         if (options)
746                 uart_parse_options(options, &baud, &parity, &bits, &flow);
747 
748         return uart_set_options(port, co, baud, parity, bits, flow);
749 }
750 
751 static struct uart_driver bcm_uart_driver;
752 
753 static struct console bcm63xx_console = {
754         .name           = "ttyS",
755         .write          = bcm_console_write,
756         .device         = uart_console_device,
757         .setup          = bcm_console_setup,
758         .flags          = CON_PRINTBUFFER,
759         .index          = -1,
760         .data           = &bcm_uart_driver,
761 };
762 
763 static int __init bcm63xx_console_init(void)
764 {
765         register_console(&bcm63xx_console);
766         return 0;
767 }
768 
769 console_initcall(bcm63xx_console_init);
770 
771 static void bcm_early_write(struct console *con, const char *s, unsigned n)
772 {
773         struct earlycon_device *dev = con->data;
774 
775         uart_console_write(&dev->port, s, n, bcm_console_putchar);
776         wait_for_xmitr(&dev->port);
777 }
778 
779 static int __init bcm_early_console_setup(struct earlycon_device *device,
780                                           const char *opt)
781 {
782         if (!device->port.membase)
783                 return -ENODEV;
784 
785         device->con->write = bcm_early_write;
786         return 0;
787 }
788 
789 OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup);
790 
791 #define BCM63XX_CONSOLE (&bcm63xx_console)
792 #else
793 #define BCM63XX_CONSOLE NULL
794 #endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
795 
796 static struct uart_driver bcm_uart_driver = {
797         .owner          = THIS_MODULE,
798         .driver_name    = "bcm63xx_uart",
799         .dev_name       = "ttyS",
800         .major          = TTY_MAJOR,
801         .minor          = 64,
802         .nr             = BCM63XX_NR_UARTS,
803         .cons           = BCM63XX_CONSOLE,
804 };
805 
806 /*
807  * platform driver probe/remove callback
808  */
809 static int bcm_uart_probe(struct platform_device *pdev)
810 {
811         struct resource *res_mem, *res_irq;
812         struct uart_port *port;
813         struct clk *clk;
814         int ret;
815 
816         if (pdev->dev.of_node)
817                 pdev->id = of_alias_get_id(pdev->dev.of_node, "uart");
818 
819         if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
820                 return -EINVAL;
821 
822         port = &ports[pdev->id];
823         if (port->membase)
824                 return -EBUSY;
825         memset(port, 0, sizeof(*port));
826 
827         res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
828         if (!res_mem)
829                 return -ENODEV;
830 
831         port->mapbase = res_mem->start;
832         port->membase = devm_ioremap_resource(&pdev->dev, res_mem);
833         if (IS_ERR(port->membase))
834                 return PTR_ERR(port->membase);
835 
836         res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
837         if (!res_irq)
838                 return -ENODEV;
839 
840         clk = pdev->dev.of_node ? of_clk_get(pdev->dev.of_node, 0) :
841                                   clk_get(&pdev->dev, "periph");
842         if (IS_ERR(clk))
843                 return -ENODEV;
844 
845         port->iotype = UPIO_MEM;
846         port->irq = res_irq->start;
847         port->ops = &bcm_uart_ops;
848         port->flags = UPF_BOOT_AUTOCONF;
849         port->dev = &pdev->dev;
850         port->fifosize = 16;
851         port->uartclk = clk_get_rate(clk) / 2;
852         port->line = pdev->id;
853         clk_put(clk);
854 
855         ret = uart_add_one_port(&bcm_uart_driver, port);
856         if (ret) {
857                 ports[pdev->id].membase = NULL;
858                 return ret;
859         }
860         platform_set_drvdata(pdev, port);
861         return 0;
862 }
863 
864 static int bcm_uart_remove(struct platform_device *pdev)
865 {
866         struct uart_port *port;
867 
868         port = platform_get_drvdata(pdev);
869         uart_remove_one_port(&bcm_uart_driver, port);
870         /* mark port as free */
871         ports[pdev->id].membase = NULL;
872         return 0;
873 }
874 
875 static const struct of_device_id bcm63xx_of_match[] = {
876         { .compatible = "brcm,bcm6345-uart" },
877         { /* sentinel */ }
878 };
879 MODULE_DEVICE_TABLE(of, bcm63xx_of_match);
880 
881 /*
882  * platform driver stuff
883  */
884 static struct platform_driver bcm_uart_platform_driver = {
885         .probe  = bcm_uart_probe,
886         .remove = bcm_uart_remove,
887         .driver = {
888                 .name  = "bcm63xx_uart",
889                 .of_match_table = bcm63xx_of_match,
890         },
891 };
892 
893 static int __init bcm_uart_init(void)
894 {
895         int ret;
896 
897         ret = uart_register_driver(&bcm_uart_driver);
898         if (ret)
899                 return ret;
900 
901         ret = platform_driver_register(&bcm_uart_platform_driver);
902         if (ret)
903                 uart_unregister_driver(&bcm_uart_driver);
904 
905         return ret;
906 }
907 
908 static void __exit bcm_uart_exit(void)
909 {
910         platform_driver_unregister(&bcm_uart_platform_driver);
911         uart_unregister_driver(&bcm_uart_driver);
912 }
913 
914 module_init(bcm_uart_init);
915 module_exit(bcm_uart_exit);
916 
917 MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
918 MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver");
919 MODULE_LICENSE("GPL");
920 

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