2 * dz.c: Serial port driver for DECstations equipped
5 * Copyright (C) 1998 Olivier A. D. Lebaillif
7 * Email: olivier.lebaillif@ifrsys.com
9 * Copyright (C) 2004, 2006, 2007 Maciej W. Rozycki
12 * Changed IRQ to use Harald's dec internals interrupts.h
13 * removed base_addr code - moving address assignment to setup.c
14 * Changed name of dz_init to rs_init to be consistent with tc code
15 * [13-NOV-98] triemer fixed code to receive characters
16 * after patches by harald to irq code.
17 * [09-JAN-99] triemer minor fix for schedule - due to removal of timeout
18 * field from "current" - somewhere between 2.1.121 and 2.1.131
19 Qua Jun 27 15:02:26 BRT 2001
20 * [27-JUN-2001] Arnaldo Carvalho de Melo <acme@conectiva.com.br> - cleanups
22 * Parts (C) 1999 David Airlie, airlied@linux.ie
23 * [07-SEP-99] Bugfixes
25 * [06-Jan-2002] Russell King <rmk@arm.linux.org.uk>
26 * Converted to new serial core
31 #if defined(CONFIG_SERIAL_DZ_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
35 #include <linux/bitops.h>
36 #include <linux/compiler.h>
37 #include <linux/console.h>
38 #include <linux/delay.h>
39 #include <linux/errno.h>
40 #include <linux/init.h>
41 #include <linux/interrupt.h>
42 #include <linux/kernel.h>
43 #include <linux/major.h>
44 #include <linux/module.h>
45 #include <linux/serial.h>
46 #include <linux/serial_core.h>
47 #include <linux/sysrq.h>
48 #include <linux/tty.h>
50 #include <asm/bootinfo.h>
51 #include <asm/system.h>
53 #include <asm/dec/interrupts.h>
54 #include <asm/dec/kn01.h>
55 #include <asm/dec/kn02.h>
56 #include <asm/dec/machtype.h>
57 #include <asm/dec/prom.h>
61 static char *dz_name = "DECstation DZ serial driver version ";
62 static char *dz_version = "1.03";
65 struct uart_port port;
69 static struct dz_port dz_ports[DZ_NB_PORT];
72 * ------------------------------------------------------------
73 * dz_in () and dz_out ()
75 * These routines are used to access the registers of the DZ
76 * chip, hiding relocation differences between implementation.
77 * ------------------------------------------------------------
80 static inline unsigned short dz_in(struct dz_port *dport, unsigned offset)
82 volatile unsigned short *addr =
83 (volatile unsigned short *) (dport->port.membase + offset);
88 static inline void dz_out(struct dz_port *dport, unsigned offset,
91 volatile unsigned short *addr =
92 (volatile unsigned short *) (dport->port.membase + offset);
98 * ------------------------------------------------------------
99 * rs_stop () and rs_start ()
101 * These routines are called before setting or resetting
102 * tty->stopped. They enable or disable transmitter interrupts,
104 * ------------------------------------------------------------
107 static void dz_stop_tx(struct uart_port *uport)
109 struct dz_port *dport = (struct dz_port *)uport;
110 unsigned short tmp, mask = 1 << dport->port.line;
113 spin_lock_irqsave(&dport->port.lock, flags);
114 tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
115 tmp &= ~mask; /* clear the TX flag */
116 dz_out(dport, DZ_TCR, tmp);
117 spin_unlock_irqrestore(&dport->port.lock, flags);
120 static void dz_start_tx(struct uart_port *uport)
122 struct dz_port *dport = (struct dz_port *)uport;
123 unsigned short tmp, mask = 1 << dport->port.line;
126 spin_lock_irqsave(&dport->port.lock, flags);
127 tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
128 tmp |= mask; /* set the TX flag */
129 dz_out(dport, DZ_TCR, tmp);
130 spin_unlock_irqrestore(&dport->port.lock, flags);
133 static void dz_stop_rx(struct uart_port *uport)
135 struct dz_port *dport = (struct dz_port *)uport;
138 spin_lock_irqsave(&dport->port.lock, flags);
139 dport->cflag &= ~DZ_CREAD;
140 dz_out(dport, DZ_LPR, dport->cflag | dport->port.line);
141 spin_unlock_irqrestore(&dport->port.lock, flags);
144 static void dz_enable_ms(struct uart_port *port)
150 * ------------------------------------------------------------
152 * Here start the interrupt handling routines. All of the following
153 * subroutines are declared as inline and are folded into
154 * dz_interrupt. They were separated out for readability's sake.
156 * Note: dz_interrupt() is a "fast" interrupt, which means that it
157 * runs with interrupts turned off. People who may want to modify
158 * dz_interrupt() should try to keep the interrupt handler as fast as
159 * possible. After you are done making modifications, it is not a bad
162 * make drivers/serial/dz.s
164 * and look at the resulting assemble code in dz.s.
166 * ------------------------------------------------------------
170 * ------------------------------------------------------------
173 * This routine deals with inputs from any lines.
174 * ------------------------------------------------------------
176 static inline void dz_receive_chars(struct dz_port *dport_in)
178 struct dz_port *dport;
179 struct tty_struct *tty = NULL;
180 struct uart_icount *icount;
181 int lines_rx[DZ_NB_PORT] = { [0 ... DZ_NB_PORT - 1] = 0 };
182 unsigned short status;
183 unsigned char ch, flag;
186 while ((status = dz_in(dport_in, DZ_RBUF)) & DZ_DVAL) {
187 dport = &dz_ports[LINE(status)];
188 tty = dport->port.info->tty; /* point to the proper dev */
190 ch = UCHAR(status); /* grab the char */
192 icount = &dport->port.icount;
196 if (status & DZ_FERR) { /* frame error */
198 * There is no separate BREAK status bit, so
199 * treat framing errors as BREAKs for Magic SysRq
200 * and SAK; normally, otherwise.
202 if (uart_handle_break(&dport->port))
204 if (dport->port.flags & UPF_SAK)
208 } else if (status & DZ_OERR) /* overrun error */
210 else if (status & DZ_PERR) /* parity error */
213 /* keep track of the statistics */
231 if (uart_handle_sysrq_char(&dport->port, ch))
234 if ((status & dport->port.ignore_status_mask) == 0) {
235 uart_insert_char(&dport->port,
236 status, DZ_OERR, ch, flag);
237 lines_rx[LINE(status)] = 1;
240 for (i = 0; i < DZ_NB_PORT; i++)
242 tty_flip_buffer_push(dz_ports[i].port.info->tty);
246 * ------------------------------------------------------------
249 * This routine deals with outputs to any lines.
250 * ------------------------------------------------------------
252 static inline void dz_transmit_chars(struct dz_port *dport_in)
254 struct dz_port *dport;
255 struct circ_buf *xmit;
256 unsigned short status;
259 status = dz_in(dport_in, DZ_CSR);
260 dport = &dz_ports[LINE(status)];
261 xmit = &dport->port.info->xmit;
263 if (dport->port.x_char) { /* XON/XOFF chars */
264 dz_out(dport, DZ_TDR, dport->port.x_char);
265 dport->port.icount.tx++;
266 dport->port.x_char = 0;
269 /* If nothing to do or stopped or hardware stopped. */
270 if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
271 dz_stop_tx(&dport->port);
276 * If something to do... (remember the dz has no output fifo,
277 * so we go one char at a time) :-<
279 tmp = xmit->buf[xmit->tail];
280 xmit->tail = (xmit->tail + 1) & (DZ_XMIT_SIZE - 1);
281 dz_out(dport, DZ_TDR, tmp);
282 dport->port.icount.tx++;
284 if (uart_circ_chars_pending(xmit) < DZ_WAKEUP_CHARS)
285 uart_write_wakeup(&dport->port);
287 /* Are we are done. */
288 if (uart_circ_empty(xmit))
289 dz_stop_tx(&dport->port);
293 * ------------------------------------------------------------
294 * check_modem_status()
296 * DS 3100 & 5100: Only valid for the MODEM line, duh!
297 * DS 5000/200: Valid for the MODEM and PRINTER line.
298 * ------------------------------------------------------------
300 static inline void check_modem_status(struct dz_port *dport)
304 * 1. No status change interrupt; use a timer.
305 * 2. Handle the 3100/5000 as appropriate. --macro
307 unsigned short status;
309 /* If not the modem line just return. */
310 if (dport->port.line != DZ_MODEM)
313 status = dz_in(dport, DZ_MSR);
315 /* it's easy, since DSR2 is the only bit in the register */
317 dport->port.icount.dsr++;
321 * ------------------------------------------------------------
324 * this is the main interrupt routine for the DZ chip.
325 * It deals with the multiple ports.
326 * ------------------------------------------------------------
328 static irqreturn_t dz_interrupt(int irq, void *dev)
330 struct dz_port *dport = dev;
331 unsigned short status;
333 /* get the reason why we just got an irq */
334 status = dz_in(dport, DZ_CSR);
336 if ((status & (DZ_RDONE | DZ_RIE)) == (DZ_RDONE | DZ_RIE))
337 dz_receive_chars(dport);
339 if ((status & (DZ_TRDY | DZ_TIE)) == (DZ_TRDY | DZ_TIE))
340 dz_transmit_chars(dport);
346 * -------------------------------------------------------------------
347 * Here ends the DZ interrupt routines.
348 * -------------------------------------------------------------------
351 static unsigned int dz_get_mctrl(struct uart_port *uport)
354 * FIXME: Handle the 3100/5000 as appropriate. --macro
356 struct dz_port *dport = (struct dz_port *)uport;
357 unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
359 if (dport->port.line == DZ_MODEM) {
360 if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR)
367 static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl)
370 * FIXME: Handle the 3100/5000 as appropriate. --macro
372 struct dz_port *dport = (struct dz_port *)uport;
375 if (dport->port.line == DZ_MODEM) {
376 tmp = dz_in(dport, DZ_TCR);
377 if (mctrl & TIOCM_DTR)
378 tmp &= ~DZ_MODEM_DTR;
381 dz_out(dport, DZ_TCR, tmp);
386 * -------------------------------------------------------------------
389 * various initialization tasks
390 * -------------------------------------------------------------------
392 static int dz_startup(struct uart_port *uport)
394 struct dz_port *dport = (struct dz_port *)uport;
398 spin_lock_irqsave(&dport->port.lock, flags);
400 /* enable the interrupt and the scanning */
401 tmp = dz_in(dport, DZ_CSR);
402 tmp |= DZ_RIE | DZ_TIE | DZ_MSE;
403 dz_out(dport, DZ_CSR, tmp);
405 spin_unlock_irqrestore(&dport->port.lock, flags);
411 * -------------------------------------------------------------------
414 * This routine will shutdown a serial port; interrupts are disabled, and
415 * DTR is dropped if the hangup on close termio flag is on.
416 * -------------------------------------------------------------------
418 static void dz_shutdown(struct uart_port *uport)
424 * -------------------------------------------------------------------
425 * dz_tx_empty() -- get the transmitter empty status
427 * Purpose: Let user call ioctl() to get info when the UART physically
428 * is emptied. On bus types like RS485, the transmitter must
429 * release the bus after transmitting. This must be done when
430 * the transmit shift register is empty, not be done when the
431 * transmit holding register is empty. This functionality
432 * allows an RS485 driver to be written in user space.
433 * -------------------------------------------------------------------
435 static unsigned int dz_tx_empty(struct uart_port *uport)
437 struct dz_port *dport = (struct dz_port *)uport;
438 unsigned short tmp, mask = 1 << dport->port.line;
440 tmp = dz_in(dport, DZ_TCR);
443 return tmp ? 0 : TIOCSER_TEMT;
446 static void dz_break_ctl(struct uart_port *uport, int break_state)
449 * FIXME: Can't access BREAK bits in TDR easily;
450 * reuse the code for polled TX. --macro
452 struct dz_port *dport = (struct dz_port *)uport;
454 unsigned short tmp, mask = 1 << dport->port.line;
456 spin_lock_irqsave(&uport->lock, flags);
457 tmp = dz_in(dport, DZ_TCR);
462 dz_out(dport, DZ_TCR, tmp);
463 spin_unlock_irqrestore(&uport->lock, flags);
466 static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
467 struct ktermios *old_termios)
469 struct dz_port *dport = (struct dz_port *)uport;
471 unsigned int cflag, baud;
473 cflag = dport->port.line;
475 switch (termios->c_cflag & CSIZE) {
490 if (termios->c_cflag & CSTOPB)
492 if (termios->c_cflag & PARENB)
494 if (termios->c_cflag & PARODD)
497 baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
546 if (termios->c_cflag & CREAD)
549 spin_lock_irqsave(&dport->port.lock, flags);
551 dz_out(dport, DZ_LPR, cflag | dport->port.line);
552 dport->cflag = cflag;
554 /* setup accept flag */
555 dport->port.read_status_mask = DZ_OERR;
556 if (termios->c_iflag & INPCK)
557 dport->port.read_status_mask |= DZ_FERR | DZ_PERR;
559 /* characters to ignore */
560 uport->ignore_status_mask = 0;
561 if (termios->c_iflag & IGNPAR)
562 dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;
564 spin_unlock_irqrestore(&dport->port.lock, flags);
567 static const char *dz_type(struct uart_port *port)
572 static void dz_release_port(struct uart_port *port)
577 static int dz_request_port(struct uart_port *port)
582 static void dz_config_port(struct uart_port *port, int flags)
584 if (flags & UART_CONFIG_TYPE)
585 port->type = PORT_DZ;
589 * verify the new serial_struct (for TIOCSSERIAL).
591 static int dz_verify_port(struct uart_port *port, struct serial_struct *ser)
594 if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ)
596 if (ser->irq != port->irq)
601 static struct uart_ops dz_ops = {
602 .tx_empty = dz_tx_empty,
603 .get_mctrl = dz_get_mctrl,
604 .set_mctrl = dz_set_mctrl,
605 .stop_tx = dz_stop_tx,
606 .start_tx = dz_start_tx,
607 .stop_rx = dz_stop_rx,
608 .enable_ms = dz_enable_ms,
609 .break_ctl = dz_break_ctl,
610 .startup = dz_startup,
611 .shutdown = dz_shutdown,
612 .set_termios = dz_set_termios,
614 .release_port = dz_release_port,
615 .request_port = dz_request_port,
616 .config_port = dz_config_port,
617 .verify_port = dz_verify_port,
620 static void __init dz_init_ports(void)
622 static int first = 1;
623 struct dz_port *dport;
631 if (mips_machtype == MACH_DS23100 ||
632 mips_machtype == MACH_DS5100)
633 base = CKSEG1ADDR(KN01_SLOT_BASE + KN01_DZ11);
635 base = CKSEG1ADDR(KN02_SLOT_BASE + KN02_DZ11);
637 for (i = 0, dport = dz_ports; i < DZ_NB_PORT; i++, dport++) {
638 spin_lock_init(&dport->port.lock);
639 dport->port.membase = (char *) base;
640 dport->port.iotype = UPIO_MEM;
641 dport->port.irq = dec_interrupt[DEC_IRQ_DZ11];
642 dport->port.line = i;
643 dport->port.fifosize = 1;
644 dport->port.ops = &dz_ops;
645 dport->port.flags = UPF_BOOT_AUTOCONF;
649 static void dz_reset(struct dz_port *dport)
651 dz_out(dport, DZ_CSR, DZ_CLR);
652 while (dz_in(dport, DZ_CSR) & DZ_CLR);
655 /* enable scanning */
656 dz_out(dport, DZ_CSR, DZ_MSE);
659 #ifdef CONFIG_SERIAL_DZ_CONSOLE
661 * -------------------------------------------------------------------
662 * dz_console_putchar() -- transmit a character
664 * Polled transmission. This is tricky. We need to mask transmit
665 * interrupts so that they do not interfere, enable the transmitter
666 * for the line requested and then wait till the transmit scanner
667 * requests data for this line. But it may request data for another
668 * line first, in which case we have to disable its transmitter and
669 * repeat waiting till our line pops up. Only then the character may
670 * be transmitted. Finally, the state of the transmitter mask is
671 * restored. Welcome to the world of PDP-11!
672 * -------------------------------------------------------------------
674 static void dz_console_putchar(struct uart_port *uport, int ch)
676 struct dz_port *dport = (struct dz_port *)uport;
678 unsigned short csr, tcr, trdy, mask;
681 spin_lock_irqsave(&dport->port.lock, flags);
682 csr = dz_in(dport, DZ_CSR);
683 dz_out(dport, DZ_CSR, csr & ~DZ_TIE);
684 tcr = dz_in(dport, DZ_TCR);
685 tcr |= 1 << dport->port.line;
687 dz_out(dport, DZ_TCR, mask);
689 spin_unlock_irqrestore(&dport->port.lock, flags);
692 trdy = dz_in(dport, DZ_CSR);
693 if (!(trdy & DZ_TRDY))
695 trdy = (trdy & DZ_TLINE) >> 8;
696 if (trdy == dport->port.line)
698 mask &= ~(1 << trdy);
699 dz_out(dport, DZ_TCR, mask);
704 if (loops) /* Cannot send otherwise. */
705 dz_out(dport, DZ_TDR, ch);
707 dz_out(dport, DZ_TCR, tcr);
708 dz_out(dport, DZ_CSR, csr);
712 * -------------------------------------------------------------------
713 * dz_console_print ()
715 * dz_console_print is registered for printk.
716 * The console must be locked when we get here.
717 * -------------------------------------------------------------------
719 static void dz_console_print(struct console *co,
723 struct dz_port *dport = &dz_ports[co->index];
725 prom_printf((char *) str);
727 uart_console_write(&dport->port, str, count, dz_console_putchar);
730 static int __init dz_console_setup(struct console *co, char *options)
732 struct dz_port *dport = &dz_ports[co->index];
739 uart_parse_options(options, &baud, &parity, &bits, &flow);
743 return uart_set_options(&dport->port, co, baud, parity, bits, flow);
746 static struct uart_driver dz_reg;
747 static struct console dz_console = {
749 .write = dz_console_print,
750 .device = uart_console_device,
751 .setup = dz_console_setup,
752 .flags = CON_PRINTBUFFER,
757 static int __init dz_serial_console_init(void)
761 register_console(&dz_console);
767 console_initcall(dz_serial_console_init);
769 #define SERIAL_DZ_CONSOLE &dz_console
771 #define SERIAL_DZ_CONSOLE NULL
772 #endif /* CONFIG_SERIAL_DZ_CONSOLE */
774 static struct uart_driver dz_reg = {
775 .owner = THIS_MODULE,
776 .driver_name = "serial",
781 .cons = SERIAL_DZ_CONSOLE,
784 static int __init dz_init(void)
791 printk("%s%s\n", dz_name, dz_version);
795 #ifndef CONFIG_SERIAL_DZ_CONSOLE
797 dz_reset(&dz_ports[0]);
800 ret = uart_register_driver(&dz_reg);
804 ret = request_irq(dz_ports[0].port.irq, dz_interrupt, IRQF_DISABLED,
807 printk(KERN_ERR "dz: Cannot get IRQ %d!\n",
808 dz_ports[0].port.irq);
812 for (i = 0; i < DZ_NB_PORT; i++)
813 uart_add_one_port(&dz_reg, &dz_ports[i].port);
818 uart_unregister_driver(&dz_reg);
824 module_init(dz_init);
826 MODULE_DESCRIPTION("DECstation DZ serial driver");
827 MODULE_LICENSE("GPL");