net: Detect and ignore netif_stop_queue() calls before register_netdev()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / serial / pnx8xxx_uart.c
blob0aa75a97531c77622e2aff05988e3a04fe242d69
1 /*
2 * UART driver for PNX8XXX SoCs
4 * Author: Per Hallsmark per.hallsmark@mvista.com
5 * Ported to 2.6 kernel by EmbeddedAlley
6 * Reworked by Vitaly Wool <vitalywool@gmail.com>
8 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
9 * Copyright (C) 2000 Deep Blue Solutions Ltd.
11 * This file is licensed under the terms of the GNU General Public License
12 * version 2. This program is licensed "as is" without any warranty of
13 * any kind, whether express or implied.
17 #if defined(CONFIG_SERIAL_PNX8XXX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
18 #define SUPPORT_SYSRQ
19 #endif
21 #include <linux/module.h>
22 #include <linux/ioport.h>
23 #include <linux/init.h>
24 #include <linux/console.h>
25 #include <linux/sysrq.h>
26 #include <linux/device.h>
27 #include <linux/platform_device.h>
28 #include <linux/tty.h>
29 #include <linux/tty_flip.h>
30 #include <linux/serial_core.h>
31 #include <linux/serial.h>
32 #include <linux/serial_pnx8xxx.h>
34 #include <asm/io.h>
35 #include <asm/irq.h>
37 /* We'll be using StrongARM sa1100 serial port major/minor */
38 #define SERIAL_PNX8XXX_MAJOR 204
39 #define MINOR_START 5
41 #define NR_PORTS 2
43 #define PNX8XXX_ISR_PASS_LIMIT 256
46 * Convert from ignore_status_mask or read_status_mask to FIFO
47 * and interrupt status bits
49 #define SM_TO_FIFO(x) ((x) >> 10)
50 #define SM_TO_ISTAT(x) ((x) & 0x000001ff)
51 #define FIFO_TO_SM(x) ((x) << 10)
52 #define ISTAT_TO_SM(x) ((x) & 0x000001ff)
55 * This is the size of our serial port register set.
57 #define UART_PORT_SIZE 0x1000
60 * This determines how often we check the modem status signals
61 * for any change. They generally aren't connected to an IRQ
62 * so we have to poll them. We also check immediately before
63 * filling the TX fifo incase CTS has been dropped.
65 #define MCTRL_TIMEOUT (250*HZ/1000)
67 extern struct pnx8xxx_port pnx8xxx_ports[];
69 static inline int serial_in(struct pnx8xxx_port *sport, int offset)
71 return (__raw_readl(sport->port.membase + offset));
74 static inline void serial_out(struct pnx8xxx_port *sport, int offset, int value)
76 __raw_writel(value, sport->port.membase + offset);
80 * Handle any change of modem status signal since we were last called.
82 static void pnx8xxx_mctrl_check(struct pnx8xxx_port *sport)
84 unsigned int status, changed;
86 status = sport->port.ops->get_mctrl(&sport->port);
87 changed = status ^ sport->old_status;
89 if (changed == 0)
90 return;
92 sport->old_status = status;
94 if (changed & TIOCM_RI)
95 sport->port.icount.rng++;
96 if (changed & TIOCM_DSR)
97 sport->port.icount.dsr++;
98 if (changed & TIOCM_CAR)
99 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
100 if (changed & TIOCM_CTS)
101 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
103 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
107 * This is our per-port timeout handler, for checking the
108 * modem status signals.
110 static void pnx8xxx_timeout(unsigned long data)
112 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)data;
113 unsigned long flags;
115 if (sport->port.state) {
116 spin_lock_irqsave(&sport->port.lock, flags);
117 pnx8xxx_mctrl_check(sport);
118 spin_unlock_irqrestore(&sport->port.lock, flags);
120 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
125 * interrupts disabled on entry
127 static void pnx8xxx_stop_tx(struct uart_port *port)
129 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
130 u32 ien;
132 /* Disable TX intr */
133 ien = serial_in(sport, PNX8XXX_IEN);
134 serial_out(sport, PNX8XXX_IEN, ien & ~PNX8XXX_UART_INT_ALLTX);
136 /* Clear all pending TX intr */
137 serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_ALLTX);
141 * interrupts may not be disabled on entry
143 static void pnx8xxx_start_tx(struct uart_port *port)
145 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
146 u32 ien;
148 /* Clear all pending TX intr */
149 serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_ALLTX);
151 /* Enable TX intr */
152 ien = serial_in(sport, PNX8XXX_IEN);
153 serial_out(sport, PNX8XXX_IEN, ien | PNX8XXX_UART_INT_ALLTX);
157 * Interrupts enabled
159 static void pnx8xxx_stop_rx(struct uart_port *port)
161 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
162 u32 ien;
164 /* Disable RX intr */
165 ien = serial_in(sport, PNX8XXX_IEN);
166 serial_out(sport, PNX8XXX_IEN, ien & ~PNX8XXX_UART_INT_ALLRX);
168 /* Clear all pending RX intr */
169 serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_ALLRX);
173 * Set the modem control timer to fire immediately.
175 static void pnx8xxx_enable_ms(struct uart_port *port)
177 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
179 mod_timer(&sport->timer, jiffies);
182 static void pnx8xxx_rx_chars(struct pnx8xxx_port *sport)
184 struct tty_struct *tty = sport->port.state->port.tty;
185 unsigned int status, ch, flg;
187 status = FIFO_TO_SM(serial_in(sport, PNX8XXX_FIFO)) |
188 ISTAT_TO_SM(serial_in(sport, PNX8XXX_ISTAT));
189 while (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFIFO)) {
190 ch = serial_in(sport, PNX8XXX_FIFO) & 0xff;
192 sport->port.icount.rx++;
194 flg = TTY_NORMAL;
197 * note that the error handling code is
198 * out of the main execution path
200 if (status & (FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE |
201 PNX8XXX_UART_FIFO_RXPAR |
202 PNX8XXX_UART_FIFO_RXBRK) |
203 ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN))) {
204 if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXBRK)) {
205 status &= ~(FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE) |
206 FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR));
207 sport->port.icount.brk++;
208 if (uart_handle_break(&sport->port))
209 goto ignore_char;
210 } else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR))
211 sport->port.icount.parity++;
212 else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE))
213 sport->port.icount.frame++;
214 if (status & ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN))
215 sport->port.icount.overrun++;
217 status &= sport->port.read_status_mask;
219 if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR))
220 flg = TTY_PARITY;
221 else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE))
222 flg = TTY_FRAME;
224 #ifdef SUPPORT_SYSRQ
225 sport->port.sysrq = 0;
226 #endif
229 if (uart_handle_sysrq_char(&sport->port, ch))
230 goto ignore_char;
232 uart_insert_char(&sport->port, status,
233 ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN), ch, flg);
235 ignore_char:
236 serial_out(sport, PNX8XXX_LCR, serial_in(sport, PNX8XXX_LCR) |
237 PNX8XXX_UART_LCR_RX_NEXT);
238 status = FIFO_TO_SM(serial_in(sport, PNX8XXX_FIFO)) |
239 ISTAT_TO_SM(serial_in(sport, PNX8XXX_ISTAT));
241 tty_flip_buffer_push(tty);
244 static void pnx8xxx_tx_chars(struct pnx8xxx_port *sport)
246 struct circ_buf *xmit = &sport->port.state->xmit;
248 if (sport->port.x_char) {
249 serial_out(sport, PNX8XXX_FIFO, sport->port.x_char);
250 sport->port.icount.tx++;
251 sport->port.x_char = 0;
252 return;
256 * Check the modem control lines before
257 * transmitting anything.
259 pnx8xxx_mctrl_check(sport);
261 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
262 pnx8xxx_stop_tx(&sport->port);
263 return;
267 * TX while bytes available
269 while (((serial_in(sport, PNX8XXX_FIFO) &
270 PNX8XXX_UART_FIFO_TXFIFO) >> 16) < 16) {
271 serial_out(sport, PNX8XXX_FIFO, xmit->buf[xmit->tail]);
272 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
273 sport->port.icount.tx++;
274 if (uart_circ_empty(xmit))
275 break;
278 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
279 uart_write_wakeup(&sport->port);
281 if (uart_circ_empty(xmit))
282 pnx8xxx_stop_tx(&sport->port);
285 static irqreturn_t pnx8xxx_int(int irq, void *dev_id)
287 struct pnx8xxx_port *sport = dev_id;
288 unsigned int status;
290 spin_lock(&sport->port.lock);
291 /* Get the interrupts */
292 status = serial_in(sport, PNX8XXX_ISTAT) & serial_in(sport, PNX8XXX_IEN);
294 /* Byte or break signal received */
295 if (status & (PNX8XXX_UART_INT_RX | PNX8XXX_UART_INT_BREAK))
296 pnx8xxx_rx_chars(sport);
298 /* TX holding register empty - transmit a byte */
299 if (status & PNX8XXX_UART_INT_TX)
300 pnx8xxx_tx_chars(sport);
302 /* Clear the ISTAT register */
303 serial_out(sport, PNX8XXX_ICLR, status);
305 spin_unlock(&sport->port.lock);
306 return IRQ_HANDLED;
310 * Return TIOCSER_TEMT when transmitter is not busy.
312 static unsigned int pnx8xxx_tx_empty(struct uart_port *port)
314 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
316 return serial_in(sport, PNX8XXX_FIFO) & PNX8XXX_UART_FIFO_TXFIFO_STA ? 0 : TIOCSER_TEMT;
319 static unsigned int pnx8xxx_get_mctrl(struct uart_port *port)
321 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
322 unsigned int mctrl = TIOCM_DSR;
323 unsigned int msr;
325 /* REVISIT */
327 msr = serial_in(sport, PNX8XXX_MCR);
329 mctrl |= msr & PNX8XXX_UART_MCR_CTS ? TIOCM_CTS : 0;
330 mctrl |= msr & PNX8XXX_UART_MCR_DCD ? TIOCM_CAR : 0;
332 return mctrl;
335 static void pnx8xxx_set_mctrl(struct uart_port *port, unsigned int mctrl)
337 #if 0 /* FIXME */
338 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
339 unsigned int msr;
340 #endif
344 * Interrupts always disabled.
346 static void pnx8xxx_break_ctl(struct uart_port *port, int break_state)
348 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
349 unsigned long flags;
350 unsigned int lcr;
352 spin_lock_irqsave(&sport->port.lock, flags);
353 lcr = serial_in(sport, PNX8XXX_LCR);
354 if (break_state == -1)
355 lcr |= PNX8XXX_UART_LCR_TXBREAK;
356 else
357 lcr &= ~PNX8XXX_UART_LCR_TXBREAK;
358 serial_out(sport, PNX8XXX_LCR, lcr);
359 spin_unlock_irqrestore(&sport->port.lock, flags);
362 static int pnx8xxx_startup(struct uart_port *port)
364 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
365 int retval;
368 * Allocate the IRQ
370 retval = request_irq(sport->port.irq, pnx8xxx_int, 0,
371 "pnx8xxx-uart", sport);
372 if (retval)
373 return retval;
376 * Finally, clear and enable interrupts
379 serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_ALLRX |
380 PNX8XXX_UART_INT_ALLTX);
382 serial_out(sport, PNX8XXX_IEN, serial_in(sport, PNX8XXX_IEN) |
383 PNX8XXX_UART_INT_ALLRX |
384 PNX8XXX_UART_INT_ALLTX);
387 * Enable modem status interrupts
389 spin_lock_irq(&sport->port.lock);
390 pnx8xxx_enable_ms(&sport->port);
391 spin_unlock_irq(&sport->port.lock);
393 return 0;
396 static void pnx8xxx_shutdown(struct uart_port *port)
398 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
399 int lcr;
402 * Stop our timer.
404 del_timer_sync(&sport->timer);
407 * Disable all interrupts
409 serial_out(sport, PNX8XXX_IEN, 0);
412 * Reset the Tx and Rx FIFOS, disable the break condition
414 lcr = serial_in(sport, PNX8XXX_LCR);
415 lcr &= ~PNX8XXX_UART_LCR_TXBREAK;
416 lcr |= PNX8XXX_UART_LCR_TX_RST | PNX8XXX_UART_LCR_RX_RST;
417 serial_out(sport, PNX8XXX_LCR, lcr);
420 * Clear all interrupts
422 serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_ALLRX |
423 PNX8XXX_UART_INT_ALLTX);
426 * Free the interrupt
428 free_irq(sport->port.irq, sport);
431 static void
432 pnx8xxx_set_termios(struct uart_port *port, struct ktermios *termios,
433 struct ktermios *old)
435 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
436 unsigned long flags;
437 unsigned int lcr_fcr, old_ien, baud, quot;
438 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
441 * We only support CS7 and CS8.
443 while ((termios->c_cflag & CSIZE) != CS7 &&
444 (termios->c_cflag & CSIZE) != CS8) {
445 termios->c_cflag &= ~CSIZE;
446 termios->c_cflag |= old_csize;
447 old_csize = CS8;
450 if ((termios->c_cflag & CSIZE) == CS8)
451 lcr_fcr = PNX8XXX_UART_LCR_8BIT;
452 else
453 lcr_fcr = 0;
455 if (termios->c_cflag & CSTOPB)
456 lcr_fcr |= PNX8XXX_UART_LCR_2STOPB;
457 if (termios->c_cflag & PARENB) {
458 lcr_fcr |= PNX8XXX_UART_LCR_PAREN;
459 if (!(termios->c_cflag & PARODD))
460 lcr_fcr |= PNX8XXX_UART_LCR_PAREVN;
464 * Ask the core to calculate the divisor for us.
466 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
467 quot = uart_get_divisor(port, baud);
469 spin_lock_irqsave(&sport->port.lock, flags);
471 sport->port.read_status_mask = ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN) |
472 ISTAT_TO_SM(PNX8XXX_UART_INT_EMPTY) |
473 ISTAT_TO_SM(PNX8XXX_UART_INT_RX);
474 if (termios->c_iflag & INPCK)
475 sport->port.read_status_mask |=
476 FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE) |
477 FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR);
478 if (termios->c_iflag & (BRKINT | PARMRK))
479 sport->port.read_status_mask |=
480 ISTAT_TO_SM(PNX8XXX_UART_INT_BREAK);
483 * Characters to ignore
485 sport->port.ignore_status_mask = 0;
486 if (termios->c_iflag & IGNPAR)
487 sport->port.ignore_status_mask |=
488 FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE) |
489 FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR);
490 if (termios->c_iflag & IGNBRK) {
491 sport->port.ignore_status_mask |=
492 ISTAT_TO_SM(PNX8XXX_UART_INT_BREAK);
494 * If we're ignoring parity and break indicators,
495 * ignore overruns too (for real raw support).
497 if (termios->c_iflag & IGNPAR)
498 sport->port.ignore_status_mask |=
499 ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN);
503 * ignore all characters if CREAD is not set
505 if ((termios->c_cflag & CREAD) == 0)
506 sport->port.ignore_status_mask |=
507 ISTAT_TO_SM(PNX8XXX_UART_INT_RX);
509 del_timer_sync(&sport->timer);
512 * Update the per-port timeout.
514 uart_update_timeout(port, termios->c_cflag, baud);
517 * disable interrupts and drain transmitter
519 old_ien = serial_in(sport, PNX8XXX_IEN);
520 serial_out(sport, PNX8XXX_IEN, old_ien & ~(PNX8XXX_UART_INT_ALLTX |
521 PNX8XXX_UART_INT_ALLRX));
523 while (serial_in(sport, PNX8XXX_FIFO) & PNX8XXX_UART_FIFO_TXFIFO_STA)
524 barrier();
526 /* then, disable everything */
527 serial_out(sport, PNX8XXX_IEN, 0);
529 /* Reset the Rx and Tx FIFOs too */
530 lcr_fcr |= PNX8XXX_UART_LCR_TX_RST;
531 lcr_fcr |= PNX8XXX_UART_LCR_RX_RST;
533 /* set the parity, stop bits and data size */
534 serial_out(sport, PNX8XXX_LCR, lcr_fcr);
536 /* set the baud rate */
537 quot -= 1;
538 serial_out(sport, PNX8XXX_BAUD, quot);
540 serial_out(sport, PNX8XXX_ICLR, -1);
542 serial_out(sport, PNX8XXX_IEN, old_ien);
544 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
545 pnx8xxx_enable_ms(&sport->port);
547 spin_unlock_irqrestore(&sport->port.lock, flags);
550 static const char *pnx8xxx_type(struct uart_port *port)
552 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
554 return sport->port.type == PORT_PNX8XXX ? "PNX8XXX" : NULL;
558 * Release the memory region(s) being used by 'port'.
560 static void pnx8xxx_release_port(struct uart_port *port)
562 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
564 release_mem_region(sport->port.mapbase, UART_PORT_SIZE);
568 * Request the memory region(s) being used by 'port'.
570 static int pnx8xxx_request_port(struct uart_port *port)
572 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
573 return request_mem_region(sport->port.mapbase, UART_PORT_SIZE,
574 "pnx8xxx-uart") != NULL ? 0 : -EBUSY;
578 * Configure/autoconfigure the port.
580 static void pnx8xxx_config_port(struct uart_port *port, int flags)
582 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
584 if (flags & UART_CONFIG_TYPE &&
585 pnx8xxx_request_port(&sport->port) == 0)
586 sport->port.type = PORT_PNX8XXX;
590 * Verify the new serial_struct (for TIOCSSERIAL).
591 * The only change we allow are to the flags and type, and
592 * even then only between PORT_PNX8XXX and PORT_UNKNOWN
594 static int
595 pnx8xxx_verify_port(struct uart_port *port, struct serial_struct *ser)
597 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
598 int ret = 0;
600 if (ser->type != PORT_UNKNOWN && ser->type != PORT_PNX8XXX)
601 ret = -EINVAL;
602 if (sport->port.irq != ser->irq)
603 ret = -EINVAL;
604 if (ser->io_type != SERIAL_IO_MEM)
605 ret = -EINVAL;
606 if (sport->port.uartclk / 16 != ser->baud_base)
607 ret = -EINVAL;
608 if ((void *)sport->port.mapbase != ser->iomem_base)
609 ret = -EINVAL;
610 if (sport->port.iobase != ser->port)
611 ret = -EINVAL;
612 if (ser->hub6 != 0)
613 ret = -EINVAL;
614 return ret;
617 static struct uart_ops pnx8xxx_pops = {
618 .tx_empty = pnx8xxx_tx_empty,
619 .set_mctrl = pnx8xxx_set_mctrl,
620 .get_mctrl = pnx8xxx_get_mctrl,
621 .stop_tx = pnx8xxx_stop_tx,
622 .start_tx = pnx8xxx_start_tx,
623 .stop_rx = pnx8xxx_stop_rx,
624 .enable_ms = pnx8xxx_enable_ms,
625 .break_ctl = pnx8xxx_break_ctl,
626 .startup = pnx8xxx_startup,
627 .shutdown = pnx8xxx_shutdown,
628 .set_termios = pnx8xxx_set_termios,
629 .type = pnx8xxx_type,
630 .release_port = pnx8xxx_release_port,
631 .request_port = pnx8xxx_request_port,
632 .config_port = pnx8xxx_config_port,
633 .verify_port = pnx8xxx_verify_port,
638 * Setup the PNX8XXX serial ports.
640 * Note also that we support "console=ttySx" where "x" is either 0 or 1.
642 static void __init pnx8xxx_init_ports(void)
644 static int first = 1;
645 int i;
647 if (!first)
648 return;
649 first = 0;
651 for (i = 0; i < NR_PORTS; i++) {
652 init_timer(&pnx8xxx_ports[i].timer);
653 pnx8xxx_ports[i].timer.function = pnx8xxx_timeout;
654 pnx8xxx_ports[i].timer.data = (unsigned long)&pnx8xxx_ports[i];
655 pnx8xxx_ports[i].port.ops = &pnx8xxx_pops;
659 #ifdef CONFIG_SERIAL_PNX8XXX_CONSOLE
661 static void pnx8xxx_console_putchar(struct uart_port *port, int ch)
663 struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
664 int status;
666 do {
667 /* Wait for UART_TX register to empty */
668 status = serial_in(sport, PNX8XXX_FIFO);
669 } while (status & PNX8XXX_UART_FIFO_TXFIFO);
670 serial_out(sport, PNX8XXX_FIFO, ch);
674 * Interrupts are disabled on entering
675 */static void
676 pnx8xxx_console_write(struct console *co, const char *s, unsigned int count)
678 struct pnx8xxx_port *sport = &pnx8xxx_ports[co->index];
679 unsigned int old_ien, status;
682 * First, save IEN and then disable interrupts
684 old_ien = serial_in(sport, PNX8XXX_IEN);
685 serial_out(sport, PNX8XXX_IEN, old_ien & ~(PNX8XXX_UART_INT_ALLTX |
686 PNX8XXX_UART_INT_ALLRX));
688 uart_console_write(&sport->port, s, count, pnx8xxx_console_putchar);
691 * Finally, wait for transmitter to become empty
692 * and restore IEN
694 do {
695 /* Wait for UART_TX register to empty */
696 status = serial_in(sport, PNX8XXX_FIFO);
697 } while (status & PNX8XXX_UART_FIFO_TXFIFO);
699 /* Clear TX and EMPTY interrupt */
700 serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_TX |
701 PNX8XXX_UART_INT_EMPTY);
703 serial_out(sport, PNX8XXX_IEN, old_ien);
706 static int __init
707 pnx8xxx_console_setup(struct console *co, char *options)
709 struct pnx8xxx_port *sport;
710 int baud = 38400;
711 int bits = 8;
712 int parity = 'n';
713 int flow = 'n';
716 * Check whether an invalid uart number has been specified, and
717 * if so, search for the first available port that does have
718 * console support.
720 if (co->index == -1 || co->index >= NR_PORTS)
721 co->index = 0;
722 sport = &pnx8xxx_ports[co->index];
724 if (options)
725 uart_parse_options(options, &baud, &parity, &bits, &flow);
727 return uart_set_options(&sport->port, co, baud, parity, bits, flow);
730 static struct uart_driver pnx8xxx_reg;
731 static struct console pnx8xxx_console = {
732 .name = "ttyS",
733 .write = pnx8xxx_console_write,
734 .device = uart_console_device,
735 .setup = pnx8xxx_console_setup,
736 .flags = CON_PRINTBUFFER,
737 .index = -1,
738 .data = &pnx8xxx_reg,
741 static int __init pnx8xxx_rs_console_init(void)
743 pnx8xxx_init_ports();
744 register_console(&pnx8xxx_console);
745 return 0;
747 console_initcall(pnx8xxx_rs_console_init);
749 #define PNX8XXX_CONSOLE &pnx8xxx_console
750 #else
751 #define PNX8XXX_CONSOLE NULL
752 #endif
754 static struct uart_driver pnx8xxx_reg = {
755 .owner = THIS_MODULE,
756 .driver_name = "ttyS",
757 .dev_name = "ttyS",
758 .major = SERIAL_PNX8XXX_MAJOR,
759 .minor = MINOR_START,
760 .nr = NR_PORTS,
761 .cons = PNX8XXX_CONSOLE,
764 static int pnx8xxx_serial_suspend(struct platform_device *pdev, pm_message_t state)
766 struct pnx8xxx_port *sport = platform_get_drvdata(pdev);
768 return uart_suspend_port(&pnx8xxx_reg, &sport->port);
771 static int pnx8xxx_serial_resume(struct platform_device *pdev)
773 struct pnx8xxx_port *sport = platform_get_drvdata(pdev);
775 return uart_resume_port(&pnx8xxx_reg, &sport->port);
778 static int pnx8xxx_serial_probe(struct platform_device *pdev)
780 struct resource *res = pdev->resource;
781 int i;
783 for (i = 0; i < pdev->num_resources; i++, res++) {
784 if (!(res->flags & IORESOURCE_MEM))
785 continue;
787 for (i = 0; i < NR_PORTS; i++) {
788 if (pnx8xxx_ports[i].port.mapbase != res->start)
789 continue;
791 pnx8xxx_ports[i].port.dev = &pdev->dev;
792 uart_add_one_port(&pnx8xxx_reg, &pnx8xxx_ports[i].port);
793 platform_set_drvdata(pdev, &pnx8xxx_ports[i]);
794 break;
798 return 0;
801 static int pnx8xxx_serial_remove(struct platform_device *pdev)
803 struct pnx8xxx_port *sport = platform_get_drvdata(pdev);
805 platform_set_drvdata(pdev, NULL);
807 if (sport)
808 uart_remove_one_port(&pnx8xxx_reg, &sport->port);
810 return 0;
813 static struct platform_driver pnx8xxx_serial_driver = {
814 .driver = {
815 .name = "pnx8xxx-uart",
816 .owner = THIS_MODULE,
818 .probe = pnx8xxx_serial_probe,
819 .remove = pnx8xxx_serial_remove,
820 .suspend = pnx8xxx_serial_suspend,
821 .resume = pnx8xxx_serial_resume,
824 static int __init pnx8xxx_serial_init(void)
826 int ret;
828 printk(KERN_INFO "Serial: PNX8XXX driver\n");
830 pnx8xxx_init_ports();
832 ret = uart_register_driver(&pnx8xxx_reg);
833 if (ret == 0) {
834 ret = platform_driver_register(&pnx8xxx_serial_driver);
835 if (ret)
836 uart_unregister_driver(&pnx8xxx_reg);
838 return ret;
841 static void __exit pnx8xxx_serial_exit(void)
843 platform_driver_unregister(&pnx8xxx_serial_driver);
844 uart_unregister_driver(&pnx8xxx_reg);
847 module_init(pnx8xxx_serial_init);
848 module_exit(pnx8xxx_serial_exit);
850 MODULE_AUTHOR("Embedded Alley Solutions, Inc.");
851 MODULE_DESCRIPTION("PNX8XXX SoCs serial port driver");
852 MODULE_LICENSE("GPL");
853 MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_PNX8XXX_MAJOR);
854 MODULE_ALIAS("platform:pnx8xxx-uart");