Version:  2.0.40 2.2.26 2.4.37 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 3.17 3.18

Linux/drivers/tty/serial/pxa.c

  1 /*
  2  *  Based on drivers/serial/8250.c by Russell King.
  3  *
  4  *  Author:     Nicolas Pitre
  5  *  Created:    Feb 20, 2003
  6  *  Copyright:  (C) 2003 Monta Vista Software, Inc.
  7  *
  8  * This program is free software; you can redistribute it and/or modify
  9  * it under the terms of the GNU General Public License as published by
 10  * the Free Software Foundation; either version 2 of the License, or
 11  * (at your option) any later version.
 12  *
 13  * Note 1: This driver is made separate from the already too overloaded
 14  * 8250.c because it needs some kirks of its own and that'll make it
 15  * easier to add DMA support.
 16  *
 17  * Note 2: I'm too sick of device allocation policies for serial ports.
 18  * If someone else wants to request an "official" allocation of major/minor
 19  * for this driver please be my guest.  And don't forget that new hardware
 20  * to come from Intel might have more than 3 or 4 of those UARTs.  Let's
 21  * hope for a better port registration and dynamic device allocation scheme
 22  * with the serial core maintainer satisfaction to appear soon.
 23  */
 24 
 25 
 26 #if defined(CONFIG_SERIAL_PXA_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
 27 #define SUPPORT_SYSRQ
 28 #endif
 29 
 30 #include <linux/module.h>
 31 #include <linux/ioport.h>
 32 #include <linux/init.h>
 33 #include <linux/console.h>
 34 #include <linux/sysrq.h>
 35 #include <linux/serial_reg.h>
 36 #include <linux/circ_buf.h>
 37 #include <linux/delay.h>
 38 #include <linux/interrupt.h>
 39 #include <linux/of.h>
 40 #include <linux/platform_device.h>
 41 #include <linux/tty.h>
 42 #include <linux/tty_flip.h>
 43 #include <linux/serial_core.h>
 44 #include <linux/clk.h>
 45 #include <linux/io.h>
 46 #include <linux/slab.h>
 47 
 48 #define PXA_NAME_LEN            8
 49 
 50 struct uart_pxa_port {
 51         struct uart_port        port;
 52         unsigned char           ier;
 53         unsigned char           lcr;
 54         unsigned char           mcr;
 55         unsigned int            lsr_break_flag;
 56         struct clk              *clk;
 57         char                    name[PXA_NAME_LEN];
 58 };
 59 
 60 static inline unsigned int serial_in(struct uart_pxa_port *up, int offset)
 61 {
 62         offset <<= 2;
 63         return readl(up->port.membase + offset);
 64 }
 65 
 66 static inline void serial_out(struct uart_pxa_port *up, int offset, int value)
 67 {
 68         offset <<= 2;
 69         writel(value, up->port.membase + offset);
 70 }
 71 
 72 static void serial_pxa_enable_ms(struct uart_port *port)
 73 {
 74         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
 75 
 76         up->ier |= UART_IER_MSI;
 77         serial_out(up, UART_IER, up->ier);
 78 }
 79 
 80 static void serial_pxa_stop_tx(struct uart_port *port)
 81 {
 82         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
 83 
 84         if (up->ier & UART_IER_THRI) {
 85                 up->ier &= ~UART_IER_THRI;
 86                 serial_out(up, UART_IER, up->ier);
 87         }
 88 }
 89 
 90 static void serial_pxa_stop_rx(struct uart_port *port)
 91 {
 92         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
 93 
 94         up->ier &= ~UART_IER_RLSI;
 95         up->port.read_status_mask &= ~UART_LSR_DR;
 96         serial_out(up, UART_IER, up->ier);
 97 }
 98 
 99 static inline void receive_chars(struct uart_pxa_port *up, int *status)
100 {
101         unsigned int ch, flag;
102         int max_count = 256;
103 
104         do {
105                 /* work around Errata #20 according to
106                  * Intel(R) PXA27x Processor Family
107                  * Specification Update (May 2005)
108                  *
109                  * Step 2
110                  * Disable the Reciever Time Out Interrupt via IER[RTOEI]
111                  */
112                 up->ier &= ~UART_IER_RTOIE;
113                 serial_out(up, UART_IER, up->ier);
114 
115                 ch = serial_in(up, UART_RX);
116                 flag = TTY_NORMAL;
117                 up->port.icount.rx++;
118 
119                 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
120                                        UART_LSR_FE | UART_LSR_OE))) {
121                         /*
122                          * For statistics only
123                          */
124                         if (*status & UART_LSR_BI) {
125                                 *status &= ~(UART_LSR_FE | UART_LSR_PE);
126                                 up->port.icount.brk++;
127                                 /*
128                                  * We do the SysRQ and SAK checking
129                                  * here because otherwise the break
130                                  * may get masked by ignore_status_mask
131                                  * or read_status_mask.
132                                  */
133                                 if (uart_handle_break(&up->port))
134                                         goto ignore_char;
135                         } else if (*status & UART_LSR_PE)
136                                 up->port.icount.parity++;
137                         else if (*status & UART_LSR_FE)
138                                 up->port.icount.frame++;
139                         if (*status & UART_LSR_OE)
140                                 up->port.icount.overrun++;
141 
142                         /*
143                          * Mask off conditions which should be ignored.
144                          */
145                         *status &= up->port.read_status_mask;
146 
147 #ifdef CONFIG_SERIAL_PXA_CONSOLE
148                         if (up->port.line == up->port.cons->index) {
149                                 /* Recover the break flag from console xmit */
150                                 *status |= up->lsr_break_flag;
151                                 up->lsr_break_flag = 0;
152                         }
153 #endif
154                         if (*status & UART_LSR_BI) {
155                                 flag = TTY_BREAK;
156                         } else if (*status & UART_LSR_PE)
157                                 flag = TTY_PARITY;
158                         else if (*status & UART_LSR_FE)
159                                 flag = TTY_FRAME;
160                 }
161 
162                 if (uart_handle_sysrq_char(&up->port, ch))
163                         goto ignore_char;
164 
165                 uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
166 
167         ignore_char:
168                 *status = serial_in(up, UART_LSR);
169         } while ((*status & UART_LSR_DR) && (max_count-- > 0));
170         tty_flip_buffer_push(&up->port.state->port);
171 
172         /* work around Errata #20 according to
173          * Intel(R) PXA27x Processor Family
174          * Specification Update (May 2005)
175          *
176          * Step 6:
177          * No more data in FIFO: Re-enable RTO interrupt via IER[RTOIE]
178          */
179         up->ier |= UART_IER_RTOIE;
180         serial_out(up, UART_IER, up->ier);
181 }
182 
183 static void transmit_chars(struct uart_pxa_port *up)
184 {
185         struct circ_buf *xmit = &up->port.state->xmit;
186         int count;
187 
188         if (up->port.x_char) {
189                 serial_out(up, UART_TX, up->port.x_char);
190                 up->port.icount.tx++;
191                 up->port.x_char = 0;
192                 return;
193         }
194         if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
195                 serial_pxa_stop_tx(&up->port);
196                 return;
197         }
198 
199         count = up->port.fifosize / 2;
200         do {
201                 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
202                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
203                 up->port.icount.tx++;
204                 if (uart_circ_empty(xmit))
205                         break;
206         } while (--count > 0);
207 
208         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
209                 uart_write_wakeup(&up->port);
210 
211 
212         if (uart_circ_empty(xmit))
213                 serial_pxa_stop_tx(&up->port);
214 }
215 
216 static void serial_pxa_start_tx(struct uart_port *port)
217 {
218         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
219 
220         if (!(up->ier & UART_IER_THRI)) {
221                 up->ier |= UART_IER_THRI;
222                 serial_out(up, UART_IER, up->ier);
223         }
224 }
225 
226 static inline void check_modem_status(struct uart_pxa_port *up)
227 {
228         int status;
229 
230         status = serial_in(up, UART_MSR);
231 
232         if ((status & UART_MSR_ANY_DELTA) == 0)
233                 return;
234 
235         if (status & UART_MSR_TERI)
236                 up->port.icount.rng++;
237         if (status & UART_MSR_DDSR)
238                 up->port.icount.dsr++;
239         if (status & UART_MSR_DDCD)
240                 uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
241         if (status & UART_MSR_DCTS)
242                 uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
243 
244         wake_up_interruptible(&up->port.state->port.delta_msr_wait);
245 }
246 
247 /*
248  * This handles the interrupt from one port.
249  */
250 static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
251 {
252         struct uart_pxa_port *up = dev_id;
253         unsigned int iir, lsr;
254 
255         iir = serial_in(up, UART_IIR);
256         if (iir & UART_IIR_NO_INT)
257                 return IRQ_NONE;
258         lsr = serial_in(up, UART_LSR);
259         if (lsr & UART_LSR_DR)
260                 receive_chars(up, &lsr);
261         check_modem_status(up);
262         if (lsr & UART_LSR_THRE)
263                 transmit_chars(up);
264         return IRQ_HANDLED;
265 }
266 
267 static unsigned int serial_pxa_tx_empty(struct uart_port *port)
268 {
269         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
270         unsigned long flags;
271         unsigned int ret;
272 
273         spin_lock_irqsave(&up->port.lock, flags);
274         ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
275         spin_unlock_irqrestore(&up->port.lock, flags);
276 
277         return ret;
278 }
279 
280 static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
281 {
282         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
283         unsigned char status;
284         unsigned int ret;
285 
286         status = serial_in(up, UART_MSR);
287 
288         ret = 0;
289         if (status & UART_MSR_DCD)
290                 ret |= TIOCM_CAR;
291         if (status & UART_MSR_RI)
292                 ret |= TIOCM_RNG;
293         if (status & UART_MSR_DSR)
294                 ret |= TIOCM_DSR;
295         if (status & UART_MSR_CTS)
296                 ret |= TIOCM_CTS;
297         return ret;
298 }
299 
300 static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
301 {
302         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
303         unsigned char mcr = 0;
304 
305         if (mctrl & TIOCM_RTS)
306                 mcr |= UART_MCR_RTS;
307         if (mctrl & TIOCM_DTR)
308                 mcr |= UART_MCR_DTR;
309         if (mctrl & TIOCM_OUT1)
310                 mcr |= UART_MCR_OUT1;
311         if (mctrl & TIOCM_OUT2)
312                 mcr |= UART_MCR_OUT2;
313         if (mctrl & TIOCM_LOOP)
314                 mcr |= UART_MCR_LOOP;
315 
316         mcr |= up->mcr;
317 
318         serial_out(up, UART_MCR, mcr);
319 }
320 
321 static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
322 {
323         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
324         unsigned long flags;
325 
326         spin_lock_irqsave(&up->port.lock, flags);
327         if (break_state == -1)
328                 up->lcr |= UART_LCR_SBC;
329         else
330                 up->lcr &= ~UART_LCR_SBC;
331         serial_out(up, UART_LCR, up->lcr);
332         spin_unlock_irqrestore(&up->port.lock, flags);
333 }
334 
335 static int serial_pxa_startup(struct uart_port *port)
336 {
337         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
338         unsigned long flags;
339         int retval;
340 
341         if (port->line == 3) /* HWUART */
342                 up->mcr |= UART_MCR_AFE;
343         else
344                 up->mcr = 0;
345 
346         up->port.uartclk = clk_get_rate(up->clk);
347 
348         /*
349          * Allocate the IRQ
350          */
351         retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
352         if (retval)
353                 return retval;
354 
355         /*
356          * Clear the FIFO buffers and disable them.
357          * (they will be reenabled in set_termios())
358          */
359         serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
360         serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
361                         UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
362         serial_out(up, UART_FCR, 0);
363 
364         /*
365          * Clear the interrupt registers.
366          */
367         (void) serial_in(up, UART_LSR);
368         (void) serial_in(up, UART_RX);
369         (void) serial_in(up, UART_IIR);
370         (void) serial_in(up, UART_MSR);
371 
372         /*
373          * Now, initialize the UART
374          */
375         serial_out(up, UART_LCR, UART_LCR_WLEN8);
376 
377         spin_lock_irqsave(&up->port.lock, flags);
378         up->port.mctrl |= TIOCM_OUT2;
379         serial_pxa_set_mctrl(&up->port, up->port.mctrl);
380         spin_unlock_irqrestore(&up->port.lock, flags);
381 
382         /*
383          * Finally, enable interrupts.  Note: Modem status interrupts
384          * are set via set_termios(), which will be occurring imminently
385          * anyway, so we don't enable them here.
386          */
387         up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
388         serial_out(up, UART_IER, up->ier);
389 
390         /*
391          * And clear the interrupt registers again for luck.
392          */
393         (void) serial_in(up, UART_LSR);
394         (void) serial_in(up, UART_RX);
395         (void) serial_in(up, UART_IIR);
396         (void) serial_in(up, UART_MSR);
397 
398         return 0;
399 }
400 
401 static void serial_pxa_shutdown(struct uart_port *port)
402 {
403         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
404         unsigned long flags;
405 
406         free_irq(up->port.irq, up);
407 
408         /*
409          * Disable interrupts from this port
410          */
411         up->ier = 0;
412         serial_out(up, UART_IER, 0);
413 
414         spin_lock_irqsave(&up->port.lock, flags);
415         up->port.mctrl &= ~TIOCM_OUT2;
416         serial_pxa_set_mctrl(&up->port, up->port.mctrl);
417         spin_unlock_irqrestore(&up->port.lock, flags);
418 
419         /*
420          * Disable break condition and FIFOs
421          */
422         serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
423         serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
424                                   UART_FCR_CLEAR_RCVR |
425                                   UART_FCR_CLEAR_XMIT);
426         serial_out(up, UART_FCR, 0);
427 }
428 
429 static void
430 serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
431                        struct ktermios *old)
432 {
433         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
434         unsigned char cval, fcr = 0;
435         unsigned long flags;
436         unsigned int baud, quot;
437         unsigned int dll;
438 
439         switch (termios->c_cflag & CSIZE) {
440         case CS5:
441                 cval = UART_LCR_WLEN5;
442                 break;
443         case CS6:
444                 cval = UART_LCR_WLEN6;
445                 break;
446         case CS7:
447                 cval = UART_LCR_WLEN7;
448                 break;
449         default:
450         case CS8:
451                 cval = UART_LCR_WLEN8;
452                 break;
453         }
454 
455         if (termios->c_cflag & CSTOPB)
456                 cval |= UART_LCR_STOP;
457         if (termios->c_cflag & PARENB)
458                 cval |= UART_LCR_PARITY;
459         if (!(termios->c_cflag & PARODD))
460                 cval |= UART_LCR_EPAR;
461 
462         /*
463          * Ask the core to calculate the divisor for us.
464          */
465         baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
466         quot = uart_get_divisor(port, baud);
467 
468         if ((up->port.uartclk / quot) < (2400 * 16))
469                 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
470         else if ((up->port.uartclk / quot) < (230400 * 16))
471                 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
472         else
473                 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;
474 
475         /*
476          * Ok, we're now changing the port state.  Do it with
477          * interrupts disabled.
478          */
479         spin_lock_irqsave(&up->port.lock, flags);
480 
481         /*
482          * Ensure the port will be enabled.
483          * This is required especially for serial console.
484          */
485         up->ier |= UART_IER_UUE;
486 
487         /*
488          * Update the per-port timeout.
489          */
490         uart_update_timeout(port, termios->c_cflag, baud);
491 
492         up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
493         if (termios->c_iflag & INPCK)
494                 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
495         if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
496                 up->port.read_status_mask |= UART_LSR_BI;
497 
498         /*
499          * Characters to ignore
500          */
501         up->port.ignore_status_mask = 0;
502         if (termios->c_iflag & IGNPAR)
503                 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
504         if (termios->c_iflag & IGNBRK) {
505                 up->port.ignore_status_mask |= UART_LSR_BI;
506                 /*
507                  * If we're ignoring parity and break indicators,
508                  * ignore overruns too (for real raw support).
509                  */
510                 if (termios->c_iflag & IGNPAR)
511                         up->port.ignore_status_mask |= UART_LSR_OE;
512         }
513 
514         /*
515          * ignore all characters if CREAD is not set
516          */
517         if ((termios->c_cflag & CREAD) == 0)
518                 up->port.ignore_status_mask |= UART_LSR_DR;
519 
520         /*
521          * CTS flow control flag and modem status interrupts
522          */
523         up->ier &= ~UART_IER_MSI;
524         if (UART_ENABLE_MS(&up->port, termios->c_cflag))
525                 up->ier |= UART_IER_MSI;
526 
527         serial_out(up, UART_IER, up->ier);
528 
529         if (termios->c_cflag & CRTSCTS)
530                 up->mcr |= UART_MCR_AFE;
531         else
532                 up->mcr &= ~UART_MCR_AFE;
533 
534         serial_out(up, UART_LCR, cval | UART_LCR_DLAB); /* set DLAB */
535         serial_out(up, UART_DLL, quot & 0xff);          /* LS of divisor */
536 
537         /*
538          * work around Errata #75 according to Intel(R) PXA27x Processor Family
539          * Specification Update (Nov 2005)
540          */
541         dll = serial_in(up, UART_DLL);
542         WARN_ON(dll != (quot & 0xff));
543 
544         serial_out(up, UART_DLM, quot >> 8);            /* MS of divisor */
545         serial_out(up, UART_LCR, cval);                 /* reset DLAB */
546         up->lcr = cval;                                 /* Save LCR */
547         serial_pxa_set_mctrl(&up->port, up->port.mctrl);
548         serial_out(up, UART_FCR, fcr);
549         spin_unlock_irqrestore(&up->port.lock, flags);
550 }
551 
552 static void
553 serial_pxa_pm(struct uart_port *port, unsigned int state,
554               unsigned int oldstate)
555 {
556         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
557 
558         if (!state)
559                 clk_prepare_enable(up->clk);
560         else
561                 clk_disable_unprepare(up->clk);
562 }
563 
564 static void serial_pxa_release_port(struct uart_port *port)
565 {
566 }
567 
568 static int serial_pxa_request_port(struct uart_port *port)
569 {
570         return 0;
571 }
572 
573 static void serial_pxa_config_port(struct uart_port *port, int flags)
574 {
575         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
576         up->port.type = PORT_PXA;
577 }
578 
579 static int
580 serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
581 {
582         /* we don't want the core code to modify any port params */
583         return -EINVAL;
584 }
585 
586 static const char *
587 serial_pxa_type(struct uart_port *port)
588 {
589         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
590         return up->name;
591 }
592 
593 static struct uart_pxa_port *serial_pxa_ports[4];
594 static struct uart_driver serial_pxa_reg;
595 
596 #ifdef CONFIG_SERIAL_PXA_CONSOLE
597 
598 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
599 
600 /*
601  *      Wait for transmitter & holding register to empty
602  */
603 static inline void wait_for_xmitr(struct uart_pxa_port *up)
604 {
605         unsigned int status, tmout = 10000;
606 
607         /* Wait up to 10ms for the character(s) to be sent. */
608         do {
609                 status = serial_in(up, UART_LSR);
610 
611                 if (status & UART_LSR_BI)
612                         up->lsr_break_flag = UART_LSR_BI;
613 
614                 if (--tmout == 0)
615                         break;
616                 udelay(1);
617         } while ((status & BOTH_EMPTY) != BOTH_EMPTY);
618 
619         /* Wait up to 1s for flow control if necessary */
620         if (up->port.flags & UPF_CONS_FLOW) {
621                 tmout = 1000000;
622                 while (--tmout &&
623                        ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
624                         udelay(1);
625         }
626 }
627 
628 static void serial_pxa_console_putchar(struct uart_port *port, int ch)
629 {
630         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
631 
632         wait_for_xmitr(up);
633         serial_out(up, UART_TX, ch);
634 }
635 
636 /*
637  * Print a string to the serial port trying not to disturb
638  * any possible real use of the port...
639  *
640  *      The console_lock must be held when we get here.
641  */
642 static void
643 serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
644 {
645         struct uart_pxa_port *up = serial_pxa_ports[co->index];
646         unsigned int ier;
647         unsigned long flags;
648         int locked = 1;
649 
650         clk_enable(up->clk);
651         local_irq_save(flags);
652         if (up->port.sysrq)
653                 locked = 0;
654         else if (oops_in_progress)
655                 locked = spin_trylock(&up->port.lock);
656         else
657                 spin_lock(&up->port.lock);
658 
659         /*
660          *      First save the IER then disable the interrupts
661          */
662         ier = serial_in(up, UART_IER);
663         serial_out(up, UART_IER, UART_IER_UUE);
664 
665         uart_console_write(&up->port, s, count, serial_pxa_console_putchar);
666 
667         /*
668          *      Finally, wait for transmitter to become empty
669          *      and restore the IER
670          */
671         wait_for_xmitr(up);
672         serial_out(up, UART_IER, ier);
673 
674         if (locked)
675                 spin_unlock(&up->port.lock);
676         local_irq_restore(flags);
677         clk_disable(up->clk);
678 
679 }
680 
681 #ifdef CONFIG_CONSOLE_POLL
682 /*
683  * Console polling routines for writing and reading from the uart while
684  * in an interrupt or debug context.
685  */
686 
687 static int serial_pxa_get_poll_char(struct uart_port *port)
688 {
689         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
690         unsigned char lsr = serial_in(up, UART_LSR);
691 
692         while (!(lsr & UART_LSR_DR))
693                 lsr = serial_in(up, UART_LSR);
694 
695         return serial_in(up, UART_RX);
696 }
697 
698 
699 static void serial_pxa_put_poll_char(struct uart_port *port,
700                          unsigned char c)
701 {
702         unsigned int ier;
703         struct uart_pxa_port *up = (struct uart_pxa_port *)port;
704 
705         /*
706          *      First save the IER then disable the interrupts
707          */
708         ier = serial_in(up, UART_IER);
709         serial_out(up, UART_IER, UART_IER_UUE);
710 
711         wait_for_xmitr(up);
712         /*
713          *      Send the character out.
714          */
715         serial_out(up, UART_TX, c);
716 
717         /*
718          *      Finally, wait for transmitter to become empty
719          *      and restore the IER
720          */
721         wait_for_xmitr(up);
722         serial_out(up, UART_IER, ier);
723 }
724 
725 #endif /* CONFIG_CONSOLE_POLL */
726 
727 static int __init
728 serial_pxa_console_setup(struct console *co, char *options)
729 {
730         struct uart_pxa_port *up;
731         int baud = 9600;
732         int bits = 8;
733         int parity = 'n';
734         int flow = 'n';
735 
736         if (co->index == -1 || co->index >= serial_pxa_reg.nr)
737                 co->index = 0;
738         up = serial_pxa_ports[co->index];
739         if (!up)
740                 return -ENODEV;
741 
742         if (options)
743                 uart_parse_options(options, &baud, &parity, &bits, &flow);
744 
745         return uart_set_options(&up->port, co, baud, parity, bits, flow);
746 }
747 
748 static struct console serial_pxa_console = {
749         .name           = "ttyS",
750         .write          = serial_pxa_console_write,
751         .device         = uart_console_device,
752         .setup          = serial_pxa_console_setup,
753         .flags          = CON_PRINTBUFFER,
754         .index          = -1,
755         .data           = &serial_pxa_reg,
756 };
757 
758 #define PXA_CONSOLE     &serial_pxa_console
759 #else
760 #define PXA_CONSOLE     NULL
761 #endif
762 
763 static struct uart_ops serial_pxa_pops = {
764         .tx_empty       = serial_pxa_tx_empty,
765         .set_mctrl      = serial_pxa_set_mctrl,
766         .get_mctrl      = serial_pxa_get_mctrl,
767         .stop_tx        = serial_pxa_stop_tx,
768         .start_tx       = serial_pxa_start_tx,
769         .stop_rx        = serial_pxa_stop_rx,
770         .enable_ms      = serial_pxa_enable_ms,
771         .break_ctl      = serial_pxa_break_ctl,
772         .startup        = serial_pxa_startup,
773         .shutdown       = serial_pxa_shutdown,
774         .set_termios    = serial_pxa_set_termios,
775         .pm             = serial_pxa_pm,
776         .type           = serial_pxa_type,
777         .release_port   = serial_pxa_release_port,
778         .request_port   = serial_pxa_request_port,
779         .config_port    = serial_pxa_config_port,
780         .verify_port    = serial_pxa_verify_port,
781 #if defined(CONFIG_CONSOLE_POLL) && defined(CONFIG_SERIAL_PXA_CONSOLE)
782         .poll_get_char = serial_pxa_get_poll_char,
783         .poll_put_char = serial_pxa_put_poll_char,
784 #endif
785 };
786 
787 static struct uart_driver serial_pxa_reg = {
788         .owner          = THIS_MODULE,
789         .driver_name    = "PXA serial",
790         .dev_name       = "ttyS",
791         .major          = TTY_MAJOR,
792         .minor          = 64,
793         .nr             = 4,
794         .cons           = PXA_CONSOLE,
795 };
796 
797 #ifdef CONFIG_PM
798 static int serial_pxa_suspend(struct device *dev)
799 {
800         struct uart_pxa_port *sport = dev_get_drvdata(dev);
801 
802         if (sport)
803                 uart_suspend_port(&serial_pxa_reg, &sport->port);
804 
805         return 0;
806 }
807 
808 static int serial_pxa_resume(struct device *dev)
809 {
810         struct uart_pxa_port *sport = dev_get_drvdata(dev);
811 
812         if (sport)
813                 uart_resume_port(&serial_pxa_reg, &sport->port);
814 
815         return 0;
816 }
817 
818 static const struct dev_pm_ops serial_pxa_pm_ops = {
819         .suspend        = serial_pxa_suspend,
820         .resume         = serial_pxa_resume,
821 };
822 #endif
823 
824 static struct of_device_id serial_pxa_dt_ids[] = {
825         { .compatible = "mrvl,pxa-uart", },
826         { .compatible = "mrvl,mmp-uart", },
827         {}
828 };
829 MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
830 
831 static int serial_pxa_probe_dt(struct platform_device *pdev,
832                                struct uart_pxa_port *sport)
833 {
834         struct device_node *np = pdev->dev.of_node;
835         int ret;
836 
837         if (!np)
838                 return 1;
839 
840         ret = of_alias_get_id(np, "serial");
841         if (ret < 0) {
842                 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
843                 return ret;
844         }
845         sport->port.line = ret;
846         return 0;
847 }
848 
849 static int serial_pxa_probe(struct platform_device *dev)
850 {
851         struct uart_pxa_port *sport;
852         struct resource *mmres, *irqres;
853         int ret;
854 
855         mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
856         irqres = platform_get_resource(dev, IORESOURCE_IRQ, 0);
857         if (!mmres || !irqres)
858                 return -ENODEV;
859 
860         sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
861         if (!sport)
862                 return -ENOMEM;
863 
864         sport->clk = clk_get(&dev->dev, NULL);
865         if (IS_ERR(sport->clk)) {
866                 ret = PTR_ERR(sport->clk);
867                 goto err_free;
868         }
869 
870         ret = clk_prepare(sport->clk);
871         if (ret) {
872                 clk_put(sport->clk);
873                 goto err_free;
874         }
875 
876         sport->port.type = PORT_PXA;
877         sport->port.iotype = UPIO_MEM;
878         sport->port.mapbase = mmres->start;
879         sport->port.irq = irqres->start;
880         sport->port.fifosize = 64;
881         sport->port.ops = &serial_pxa_pops;
882         sport->port.dev = &dev->dev;
883         sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
884         sport->port.uartclk = clk_get_rate(sport->clk);
885 
886         ret = serial_pxa_probe_dt(dev, sport);
887         if (ret > 0)
888                 sport->port.line = dev->id;
889         else if (ret < 0)
890                 goto err_clk;
891         snprintf(sport->name, PXA_NAME_LEN - 1, "UART%d", sport->port.line + 1);
892 
893         sport->port.membase = ioremap(mmres->start, resource_size(mmres));
894         if (!sport->port.membase) {
895                 ret = -ENOMEM;
896                 goto err_clk;
897         }
898 
899         serial_pxa_ports[sport->port.line] = sport;
900 
901         uart_add_one_port(&serial_pxa_reg, &sport->port);
902         platform_set_drvdata(dev, sport);
903 
904         return 0;
905 
906  err_clk:
907         clk_unprepare(sport->clk);
908         clk_put(sport->clk);
909  err_free:
910         kfree(sport);
911         return ret;
912 }
913 
914 static int serial_pxa_remove(struct platform_device *dev)
915 {
916         struct uart_pxa_port *sport = platform_get_drvdata(dev);
917 
918         uart_remove_one_port(&serial_pxa_reg, &sport->port);
919 
920         clk_unprepare(sport->clk);
921         clk_put(sport->clk);
922         kfree(sport);
923 
924         return 0;
925 }
926 
927 static struct platform_driver serial_pxa_driver = {
928         .probe          = serial_pxa_probe,
929         .remove         = serial_pxa_remove,
930 
931         .driver         = {
932                 .name   = "pxa2xx-uart",
933                 .owner  = THIS_MODULE,
934 #ifdef CONFIG_PM
935                 .pm     = &serial_pxa_pm_ops,
936 #endif
937                 .of_match_table = serial_pxa_dt_ids,
938         },
939 };
940 
941 static int __init serial_pxa_init(void)
942 {
943         int ret;
944 
945         ret = uart_register_driver(&serial_pxa_reg);
946         if (ret != 0)
947                 return ret;
948 
949         ret = platform_driver_register(&serial_pxa_driver);
950         if (ret != 0)
951                 uart_unregister_driver(&serial_pxa_reg);
952 
953         return ret;
954 }
955 
956 static void __exit serial_pxa_exit(void)
957 {
958         platform_driver_unregister(&serial_pxa_driver);
959         uart_unregister_driver(&serial_pxa_reg);
960 }
961 
962 module_init(serial_pxa_init);
963 module_exit(serial_pxa_exit);
964 
965 MODULE_LICENSE("GPL");
966 MODULE_ALIAS("platform:pxa2xx-uart");
967 

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