2 * linux/drivers/char/8250.c
4 * Driver for 8250/16550-type serial ports
6 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
8 * Copyright (C) 2001 Russell King.
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * A note about mapbase / membase
17 * mapbase is the physical address of the IO port.
18 * membase is an 'ioremapped' cookie.
21 #if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/ioport.h>
28 #include <linux/init.h>
29 #include <linux/console.h>
30 #include <linux/sysrq.h>
31 #include <linux/delay.h>
32 #include <linux/platform_device.h>
33 #include <linux/tty.h>
34 #include <linux/tty_flip.h>
35 #include <linux/serial_reg.h>
36 #include <linux/serial_core.h>
37 #include <linux/serial.h>
38 #include <linux/serial_8250.h>
39 #include <linux/nmi.h>
40 #include <linux/mutex.h>
53 * share_irqs - whether we pass IRQF_SHARED to request_irq(). This option
54 * is unsafe when used on edge-triggered interrupts.
56 static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
58 static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
60 static struct uart_driver serial8250_reg;
62 static int serial_index(struct uart_port *port)
64 return (serial8250_reg.minor - 64) + port->line;
71 #define DEBUG_AUTOCONF(fmt...) printk(fmt)
73 #define DEBUG_AUTOCONF(fmt...) do { } while (0)
77 #define DEBUG_INTR(fmt...) printk(fmt)
79 #define DEBUG_INTR(fmt...) do { } while (0)
82 #define PASS_LIMIT 256
85 * We default to IRQ0 for the "no irq" hack. Some
86 * machine types want others as well - they're free
87 * to redefine this in their header file.
89 #define is_real_interrupt(irq) ((irq) != 0)
91 #ifdef CONFIG_SERIAL_8250_DETECT_IRQ
92 #define CONFIG_SERIAL_DETECT_IRQ 1
94 #ifdef CONFIG_SERIAL_8250_MANY_PORTS
95 #define CONFIG_SERIAL_MANY_PORTS 1
99 * HUB6 is always on. This will be removed once the header
100 * files have been cleaned.
102 #define CONFIG_HUB6 1
104 #include <asm/serial.h>
106 * SERIAL_PORT_DFNS tells us about built-in ports that have no
107 * standard enumeration mechanism. Platforms that can find all
108 * serial ports via mechanisms like ACPI or PCI need not supply it.
110 #ifndef SERIAL_PORT_DFNS
111 #define SERIAL_PORT_DFNS
114 static const struct old_serial_port old_serial_port[] = {
115 SERIAL_PORT_DFNS /* defined in asm/serial.h */
118 #define UART_NR CONFIG_SERIAL_8250_NR_UARTS
120 #ifdef CONFIG_SERIAL_8250_RSA
122 #define PORT_RSA_MAX 4
123 static unsigned long probe_rsa[PORT_RSA_MAX];
124 static unsigned int probe_rsa_count;
125 #endif /* CONFIG_SERIAL_8250_RSA */
127 struct uart_8250_port {
128 struct uart_port port;
129 struct timer_list timer; /* "no irq" timer */
130 struct list_head list; /* ports on this IRQ */
131 unsigned short capabilities; /* port capabilities */
132 unsigned short bugs; /* port bugs */
133 unsigned int tx_loadsz; /* transmit fifo load size */
138 unsigned char mcr_mask; /* mask of user bits */
139 unsigned char mcr_force; /* mask of forced bits */
142 * Some bits in registers are cleared on a read, so they must
143 * be saved whenever the register is read but the bits will not
144 * be immediately processed.
146 #define LSR_SAVE_FLAGS UART_LSR_BRK_ERROR_BITS
147 unsigned char lsr_saved_flags;
148 #define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
149 unsigned char msr_saved_flags;
152 * We provide a per-port pm hook.
154 void (*pm)(struct uart_port *port,
155 unsigned int state, unsigned int old);
159 struct hlist_node node;
161 spinlock_t lock; /* Protects list not the hash */
162 struct list_head *head;
165 #define NR_IRQ_HASH 32 /* Can be adjusted later */
166 static struct hlist_head irq_lists[NR_IRQ_HASH];
167 static DEFINE_MUTEX(hash_mutex); /* Used to walk the hash */
170 * Here we define the default xmit fifo size used for each type of UART.
172 static const struct serial8250_config uart_config[] = {
197 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
198 .flags = UART_CAP_FIFO,
209 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
215 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
217 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
223 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
225 .flags = UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE,
233 .name = "16C950/954",
236 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
237 .flags = UART_CAP_FIFO,
243 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
245 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
251 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
252 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
258 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11,
259 .flags = UART_CAP_FIFO,
265 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
266 .flags = UART_CAP_FIFO | UART_NATSEMI,
272 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
273 .flags = UART_CAP_FIFO | UART_CAP_UUE,
279 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
280 .flags = UART_CAP_FIFO,
286 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
287 .flags = UART_CAP_FIFO,
291 #if defined (CONFIG_SERIAL_8250_AU1X00)
293 /* Au1x00 UART hardware has a weird register layout */
294 static const u8 au_io_in_map[] = {
304 static const u8 au_io_out_map[] = {
312 /* sane hardware needs no mapping */
313 static inline int map_8250_in_reg(struct uart_port *p, int offset)
315 if (p->iotype != UPIO_AU)
317 return au_io_in_map[offset];
320 static inline int map_8250_out_reg(struct uart_port *p, int offset)
322 if (p->iotype != UPIO_AU)
324 return au_io_out_map[offset];
327 #elif defined(CONFIG_SERIAL_8250_RM9K)
351 static inline int map_8250_in_reg(struct uart_port *p, int offset)
353 if (p->iotype != UPIO_RM9000)
355 return regmap_in[offset];
358 static inline int map_8250_out_reg(struct uart_port *p, int offset)
360 if (p->iotype != UPIO_RM9000)
362 return regmap_out[offset];
367 /* sane hardware needs no mapping */
368 #define map_8250_in_reg(up, offset) (offset)
369 #define map_8250_out_reg(up, offset) (offset)
373 static unsigned int hub6_serial_in(struct uart_port *p, int offset)
375 offset = map_8250_in_reg(p, offset) << p->regshift;
376 outb(p->hub6 - 1 + offset, p->iobase);
377 return inb(p->iobase + 1);
380 static void hub6_serial_out(struct uart_port *p, int offset, int value)
382 offset = map_8250_out_reg(p, offset) << p->regshift;
383 outb(p->hub6 - 1 + offset, p->iobase);
384 outb(value, p->iobase + 1);
387 static unsigned int mem_serial_in(struct uart_port *p, int offset)
389 offset = map_8250_in_reg(p, offset) << p->regshift;
390 return readb(p->membase + offset);
393 static void mem_serial_out(struct uart_port *p, int offset, int value)
395 offset = map_8250_out_reg(p, offset) << p->regshift;
396 writeb(value, p->membase + offset);
399 static void mem32_serial_out(struct uart_port *p, int offset, int value)
401 offset = map_8250_out_reg(p, offset) << p->regshift;
402 writel(value, p->membase + offset);
405 static unsigned int mem32_serial_in(struct uart_port *p, int offset)
407 offset = map_8250_in_reg(p, offset) << p->regshift;
408 return readl(p->membase + offset);
411 #ifdef CONFIG_SERIAL_8250_AU1X00
412 static unsigned int au_serial_in(struct uart_port *p, int offset)
414 offset = map_8250_in_reg(p, offset) << p->regshift;
415 return __raw_readl(p->membase + offset);
418 static void au_serial_out(struct uart_port *p, int offset, int value)
420 offset = map_8250_out_reg(p, offset) << p->regshift;
421 __raw_writel(value, p->membase + offset);
425 static unsigned int tsi_serial_in(struct uart_port *p, int offset)
428 offset = map_8250_in_reg(p, offset) << p->regshift;
429 if (offset == UART_IIR) {
430 tmp = readl(p->membase + (UART_IIR & ~3));
431 return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
433 return readb(p->membase + offset);
436 static void tsi_serial_out(struct uart_port *p, int offset, int value)
438 offset = map_8250_out_reg(p, offset) << p->regshift;
439 if (!((offset == UART_IER) && (value & UART_IER_UUE)))
440 writeb(value, p->membase + offset);
443 static void dwapb_serial_out(struct uart_port *p, int offset, int value)
445 int save_offset = offset;
446 offset = map_8250_out_reg(p, offset) << p->regshift;
447 /* Save the LCR value so it can be re-written when a
448 * Busy Detect interrupt occurs. */
449 if (save_offset == UART_LCR) {
450 struct uart_8250_port *up = (struct uart_8250_port *)p;
453 writeb(value, p->membase + offset);
454 /* Read the IER to ensure any interrupt is cleared before
455 * returning from ISR. */
456 if (save_offset == UART_TX || save_offset == UART_IER)
457 value = p->serial_in(p, UART_IER);
460 static unsigned int io_serial_in(struct uart_port *p, int offset)
462 offset = map_8250_in_reg(p, offset) << p->regshift;
463 return inb(p->iobase + offset);
466 static void io_serial_out(struct uart_port *p, int offset, int value)
468 offset = map_8250_out_reg(p, offset) << p->regshift;
469 outb(value, p->iobase + offset);
472 static void set_io_from_upio(struct uart_port *p)
476 p->serial_in = hub6_serial_in;
477 p->serial_out = hub6_serial_out;
481 p->serial_in = mem_serial_in;
482 p->serial_out = mem_serial_out;
487 p->serial_in = mem32_serial_in;
488 p->serial_out = mem32_serial_out;
491 #ifdef CONFIG_SERIAL_8250_AU1X00
493 p->serial_in = au_serial_in;
494 p->serial_out = au_serial_out;
498 p->serial_in = tsi_serial_in;
499 p->serial_out = tsi_serial_out;
503 p->serial_in = mem_serial_in;
504 p->serial_out = dwapb_serial_out;
508 p->serial_in = io_serial_in;
509 p->serial_out = io_serial_out;
515 serial_out_sync(struct uart_8250_port *up, int offset, int value)
517 struct uart_port *p = &up->port;
521 #ifdef CONFIG_SERIAL_8250_AU1X00
525 p->serial_out(p, offset, value);
526 p->serial_in(p, UART_LCR); /* safe, no side-effects */
529 p->serial_out(p, offset, value);
533 #define serial_in(up, offset) \
534 (up->port.serial_in(&(up)->port, (offset)))
535 #define serial_out(up, offset, value) \
536 (up->port.serial_out(&(up)->port, (offset), (value)))
538 * We used to support using pause I/O for certain machines. We
539 * haven't supported this for a while, but just in case it's badly
540 * needed for certain old 386 machines, I've left these #define's
543 #define serial_inp(up, offset) serial_in(up, offset)
544 #define serial_outp(up, offset, value) serial_out(up, offset, value)
546 /* Uart divisor latch read */
547 static inline int _serial_dl_read(struct uart_8250_port *up)
549 return serial_inp(up, UART_DLL) | serial_inp(up, UART_DLM) << 8;
552 /* Uart divisor latch write */
553 static inline void _serial_dl_write(struct uart_8250_port *up, int value)
555 serial_outp(up, UART_DLL, value & 0xff);
556 serial_outp(up, UART_DLM, value >> 8 & 0xff);
559 #if defined(CONFIG_SERIAL_8250_AU1X00)
560 /* Au1x00 haven't got a standard divisor latch */
561 static int serial_dl_read(struct uart_8250_port *up)
563 if (up->port.iotype == UPIO_AU)
564 return __raw_readl(up->port.membase + 0x28);
566 return _serial_dl_read(up);
569 static void serial_dl_write(struct uart_8250_port *up, int value)
571 if (up->port.iotype == UPIO_AU)
572 __raw_writel(value, up->port.membase + 0x28);
574 _serial_dl_write(up, value);
576 #elif defined(CONFIG_SERIAL_8250_RM9K)
577 static int serial_dl_read(struct uart_8250_port *up)
579 return (up->port.iotype == UPIO_RM9000) ?
580 (((__raw_readl(up->port.membase + 0x10) << 8) |
581 (__raw_readl(up->port.membase + 0x08) & 0xff)) & 0xffff) :
585 static void serial_dl_write(struct uart_8250_port *up, int value)
587 if (up->port.iotype == UPIO_RM9000) {
588 __raw_writel(value, up->port.membase + 0x08);
589 __raw_writel(value >> 8, up->port.membase + 0x10);
591 _serial_dl_write(up, value);
595 #define serial_dl_read(up) _serial_dl_read(up)
596 #define serial_dl_write(up, value) _serial_dl_write(up, value)
602 static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
604 serial_out(up, UART_SCR, offset);
605 serial_out(up, UART_ICR, value);
608 static unsigned int serial_icr_read(struct uart_8250_port *up, int offset)
612 serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
613 serial_out(up, UART_SCR, offset);
614 value = serial_in(up, UART_ICR);
615 serial_icr_write(up, UART_ACR, up->acr);
623 static void serial8250_clear_fifos(struct uart_8250_port *p)
625 if (p->capabilities & UART_CAP_FIFO) {
626 serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO);
627 serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO |
628 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
629 serial_outp(p, UART_FCR, 0);
634 * IER sleep support. UARTs which have EFRs need the "extended
635 * capability" bit enabled. Note that on XR16C850s, we need to
636 * reset LCR to write to IER.
638 static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
640 if (p->capabilities & UART_CAP_SLEEP) {
641 if (p->capabilities & UART_CAP_EFR) {
642 serial_outp(p, UART_LCR, 0xBF);
643 serial_outp(p, UART_EFR, UART_EFR_ECB);
644 serial_outp(p, UART_LCR, 0);
646 serial_outp(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
647 if (p->capabilities & UART_CAP_EFR) {
648 serial_outp(p, UART_LCR, 0xBF);
649 serial_outp(p, UART_EFR, 0);
650 serial_outp(p, UART_LCR, 0);
655 #ifdef CONFIG_SERIAL_8250_RSA
657 * Attempts to turn on the RSA FIFO. Returns zero on failure.
658 * We set the port uart clock rate if we succeed.
660 static int __enable_rsa(struct uart_8250_port *up)
665 mode = serial_inp(up, UART_RSA_MSR);
666 result = mode & UART_RSA_MSR_FIFO;
669 serial_outp(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
670 mode = serial_inp(up, UART_RSA_MSR);
671 result = mode & UART_RSA_MSR_FIFO;
675 up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
680 static void enable_rsa(struct uart_8250_port *up)
682 if (up->port.type == PORT_RSA) {
683 if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
684 spin_lock_irq(&up->port.lock);
686 spin_unlock_irq(&up->port.lock);
688 if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
689 serial_outp(up, UART_RSA_FRR, 0);
694 * Attempts to turn off the RSA FIFO. Returns zero on failure.
695 * It is unknown why interrupts were disabled in here. However,
696 * the caller is expected to preserve this behaviour by grabbing
697 * the spinlock before calling this function.
699 static void disable_rsa(struct uart_8250_port *up)
704 if (up->port.type == PORT_RSA &&
705 up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
706 spin_lock_irq(&up->port.lock);
708 mode = serial_inp(up, UART_RSA_MSR);
709 result = !(mode & UART_RSA_MSR_FIFO);
712 serial_outp(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
713 mode = serial_inp(up, UART_RSA_MSR);
714 result = !(mode & UART_RSA_MSR_FIFO);
718 up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
719 spin_unlock_irq(&up->port.lock);
722 #endif /* CONFIG_SERIAL_8250_RSA */
725 * This is a quickie test to see how big the FIFO is.
726 * It doesn't work at all the time, more's the pity.
728 static int size_fifo(struct uart_8250_port *up)
730 unsigned char old_fcr, old_mcr, old_lcr;
731 unsigned short old_dl;
734 old_lcr = serial_inp(up, UART_LCR);
735 serial_outp(up, UART_LCR, 0);
736 old_fcr = serial_inp(up, UART_FCR);
737 old_mcr = serial_inp(up, UART_MCR);
738 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
739 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
740 serial_outp(up, UART_MCR, UART_MCR_LOOP);
741 serial_outp(up, UART_LCR, UART_LCR_DLAB);
742 old_dl = serial_dl_read(up);
743 serial_dl_write(up, 0x0001);
744 serial_outp(up, UART_LCR, 0x03);
745 for (count = 0; count < 256; count++)
746 serial_outp(up, UART_TX, count);
747 mdelay(20);/* FIXME - schedule_timeout */
748 for (count = 0; (serial_inp(up, UART_LSR) & UART_LSR_DR) &&
749 (count < 256); count++)
750 serial_inp(up, UART_RX);
751 serial_outp(up, UART_FCR, old_fcr);
752 serial_outp(up, UART_MCR, old_mcr);
753 serial_outp(up, UART_LCR, UART_LCR_DLAB);
754 serial_dl_write(up, old_dl);
755 serial_outp(up, UART_LCR, old_lcr);
761 * Read UART ID using the divisor method - set DLL and DLM to zero
762 * and the revision will be in DLL and device type in DLM. We
763 * preserve the device state across this.
765 static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
767 unsigned char old_dll, old_dlm, old_lcr;
770 old_lcr = serial_inp(p, UART_LCR);
771 serial_outp(p, UART_LCR, UART_LCR_DLAB);
773 old_dll = serial_inp(p, UART_DLL);
774 old_dlm = serial_inp(p, UART_DLM);
776 serial_outp(p, UART_DLL, 0);
777 serial_outp(p, UART_DLM, 0);
779 id = serial_inp(p, UART_DLL) | serial_inp(p, UART_DLM) << 8;
781 serial_outp(p, UART_DLL, old_dll);
782 serial_outp(p, UART_DLM, old_dlm);
783 serial_outp(p, UART_LCR, old_lcr);
789 * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's.
790 * When this function is called we know it is at least a StarTech
791 * 16650 V2, but it might be one of several StarTech UARTs, or one of
792 * its clones. (We treat the broken original StarTech 16650 V1 as a
793 * 16550, and why not? Startech doesn't seem to even acknowledge its
796 * What evil have men's minds wrought...
798 static void autoconfig_has_efr(struct uart_8250_port *up)
800 unsigned int id1, id2, id3, rev;
803 * Everything with an EFR has SLEEP
805 up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
808 * First we check to see if it's an Oxford Semiconductor UART.
810 * If we have to do this here because some non-National
811 * Semiconductor clone chips lock up if you try writing to the
812 * LSR register (which serial_icr_read does)
816 * Check for Oxford Semiconductor 16C950.
818 * EFR [4] must be set else this test fails.
820 * This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca)
821 * claims that it's needed for 952 dual UART's (which are not
822 * recommended for new designs).
825 serial_out(up, UART_LCR, 0xBF);
826 serial_out(up, UART_EFR, UART_EFR_ECB);
827 serial_out(up, UART_LCR, 0x00);
828 id1 = serial_icr_read(up, UART_ID1);
829 id2 = serial_icr_read(up, UART_ID2);
830 id3 = serial_icr_read(up, UART_ID3);
831 rev = serial_icr_read(up, UART_REV);
833 DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);
835 if (id1 == 0x16 && id2 == 0xC9 &&
836 (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
837 up->port.type = PORT_16C950;
840 * Enable work around for the Oxford Semiconductor 952 rev B
841 * chip which causes it to seriously miscalculate baud rates
844 if (id3 == 0x52 && rev == 0x01)
845 up->bugs |= UART_BUG_QUOT;
850 * We check for a XR16C850 by setting DLL and DLM to 0, and then
851 * reading back DLL and DLM. The chip type depends on the DLM
853 * 0x10 - XR16C850 and the DLL contains the chip revision.
857 id1 = autoconfig_read_divisor_id(up);
858 DEBUG_AUTOCONF("850id=%04x ", id1);
861 if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
862 up->port.type = PORT_16850;
867 * It wasn't an XR16C850.
869 * We distinguish between the '654 and the '650 by counting
870 * how many bytes are in the FIFO. I'm using this for now,
871 * since that's the technique that was sent to me in the
872 * serial driver update, but I'm not convinced this works.
873 * I've had problems doing this in the past. -TYT
875 if (size_fifo(up) == 64)
876 up->port.type = PORT_16654;
878 up->port.type = PORT_16650V2;
882 * We detected a chip without a FIFO. Only two fall into
883 * this category - the original 8250 and the 16450. The
884 * 16450 has a scratch register (accessible with LCR=0)
886 static void autoconfig_8250(struct uart_8250_port *up)
888 unsigned char scratch, status1, status2;
890 up->port.type = PORT_8250;
892 scratch = serial_in(up, UART_SCR);
893 serial_outp(up, UART_SCR, 0xa5);
894 status1 = serial_in(up, UART_SCR);
895 serial_outp(up, UART_SCR, 0x5a);
896 status2 = serial_in(up, UART_SCR);
897 serial_outp(up, UART_SCR, scratch);
899 if (status1 == 0xa5 && status2 == 0x5a)
900 up->port.type = PORT_16450;
903 static int broken_efr(struct uart_8250_port *up)
906 * Exar ST16C2550 "A2" devices incorrectly detect as
907 * having an EFR, and report an ID of 0x0201. See
908 * http://www.exar.com/info.php?pdf=dan180_oct2004.pdf
910 if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
917 * We know that the chip has FIFOs. Does it have an EFR? The
918 * EFR is located in the same register position as the IIR and
919 * we know the top two bits of the IIR are currently set. The
920 * EFR should contain zero. Try to read the EFR.
922 static void autoconfig_16550a(struct uart_8250_port *up)
924 unsigned char status1, status2;
925 unsigned int iersave;
927 up->port.type = PORT_16550A;
928 up->capabilities |= UART_CAP_FIFO;
931 * Check for presence of the EFR when DLAB is set.
932 * Only ST16C650V1 UARTs pass this test.
934 serial_outp(up, UART_LCR, UART_LCR_DLAB);
935 if (serial_in(up, UART_EFR) == 0) {
936 serial_outp(up, UART_EFR, 0xA8);
937 if (serial_in(up, UART_EFR) != 0) {
938 DEBUG_AUTOCONF("EFRv1 ");
939 up->port.type = PORT_16650;
940 up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
942 DEBUG_AUTOCONF("Motorola 8xxx DUART ");
944 serial_outp(up, UART_EFR, 0);
949 * Maybe it requires 0xbf to be written to the LCR.
950 * (other ST16C650V2 UARTs, TI16C752A, etc)
952 serial_outp(up, UART_LCR, 0xBF);
953 if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
954 DEBUG_AUTOCONF("EFRv2 ");
955 autoconfig_has_efr(up);
960 * Check for a National Semiconductor SuperIO chip.
961 * Attempt to switch to bank 2, read the value of the LOOP bit
962 * from EXCR1. Switch back to bank 0, change it in MCR. Then
963 * switch back to bank 2, read it from EXCR1 again and check
964 * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2
966 serial_outp(up, UART_LCR, 0);
967 status1 = serial_in(up, UART_MCR);
968 serial_outp(up, UART_LCR, 0xE0);
969 status2 = serial_in(up, 0x02); /* EXCR1 */
971 if (!((status2 ^ status1) & UART_MCR_LOOP)) {
972 serial_outp(up, UART_LCR, 0);
973 serial_outp(up, UART_MCR, status1 ^ UART_MCR_LOOP);
974 serial_outp(up, UART_LCR, 0xE0);
975 status2 = serial_in(up, 0x02); /* EXCR1 */
976 serial_outp(up, UART_LCR, 0);
977 serial_outp(up, UART_MCR, status1);
979 if ((status2 ^ status1) & UART_MCR_LOOP) {
982 serial_outp(up, UART_LCR, 0xE0);
984 quot = serial_dl_read(up);
987 status1 = serial_in(up, 0x04); /* EXCR2 */
988 status1 &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
989 status1 |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
990 serial_outp(up, 0x04, status1);
992 serial_dl_write(up, quot);
994 serial_outp(up, UART_LCR, 0);
996 up->port.uartclk = 921600*16;
997 up->port.type = PORT_NS16550A;
998 up->capabilities |= UART_NATSEMI;
1004 * No EFR. Try to detect a TI16750, which only sets bit 5 of
1005 * the IIR when 64 byte FIFO mode is enabled when DLAB is set.
1006 * Try setting it with and without DLAB set. Cheap clones
1007 * set bit 5 without DLAB set.
1009 serial_outp(up, UART_LCR, 0);
1010 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
1011 status1 = serial_in(up, UART_IIR) >> 5;
1012 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1013 serial_outp(up, UART_LCR, UART_LCR_DLAB);
1014 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
1015 status2 = serial_in(up, UART_IIR) >> 5;
1016 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1017 serial_outp(up, UART_LCR, 0);
1019 DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
1021 if (status1 == 6 && status2 == 7) {
1022 up->port.type = PORT_16750;
1023 up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
1028 * Try writing and reading the UART_IER_UUE bit (b6).
1029 * If it works, this is probably one of the Xscale platform's
1031 * We're going to explicitly set the UUE bit to 0 before
1032 * trying to write and read a 1 just to make sure it's not
1033 * already a 1 and maybe locked there before we even start start.
1035 iersave = serial_in(up, UART_IER);
1036 serial_outp(up, UART_IER, iersave & ~UART_IER_UUE);
1037 if (!(serial_in(up, UART_IER) & UART_IER_UUE)) {
1039 * OK it's in a known zero state, try writing and reading
1040 * without disturbing the current state of the other bits.
1042 serial_outp(up, UART_IER, iersave | UART_IER_UUE);
1043 if (serial_in(up, UART_IER) & UART_IER_UUE) {
1046 * We'll leave the UART_IER_UUE bit set to 1 (enabled).
1048 DEBUG_AUTOCONF("Xscale ");
1049 up->port.type = PORT_XSCALE;
1050 up->capabilities |= UART_CAP_UUE;
1055 * If we got here we couldn't force the IER_UUE bit to 0.
1056 * Log it and continue.
1058 DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
1060 serial_outp(up, UART_IER, iersave);
1064 * This routine is called by rs_init() to initialize a specific serial
1065 * port. It determines what type of UART chip this serial port is
1066 * using: 8250, 16450, 16550, 16550A. The important question is
1067 * whether or not this UART is a 16550A or not, since this will
1068 * determine whether or not we can use its FIFO features or not.
1070 static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
1072 unsigned char status1, scratch, scratch2, scratch3;
1073 unsigned char save_lcr, save_mcr;
1074 unsigned long flags;
1076 if (!up->port.iobase && !up->port.mapbase && !up->port.membase)
1079 DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04x, 0x%p): ",
1080 serial_index(&up->port), up->port.iobase, up->port.membase);
1083 * We really do need global IRQs disabled here - we're going to
1084 * be frobbing the chips IRQ enable register to see if it exists.
1086 spin_lock_irqsave(&up->port.lock, flags);
1088 up->capabilities = 0;
1091 if (!(up->port.flags & UPF_BUGGY_UART)) {
1093 * Do a simple existence test first; if we fail this,
1094 * there's no point trying anything else.
1096 * 0x80 is used as a nonsense port to prevent against
1097 * false positives due to ISA bus float. The
1098 * assumption is that 0x80 is a non-existent port;
1099 * which should be safe since include/asm/io.h also
1100 * makes this assumption.
1102 * Note: this is safe as long as MCR bit 4 is clear
1103 * and the device is in "PC" mode.
1105 scratch = serial_inp(up, UART_IER);
1106 serial_outp(up, UART_IER, 0);
1111 * Mask out IER[7:4] bits for test as some UARTs (e.g. TL
1112 * 16C754B) allow only to modify them if an EFR bit is set.
1114 scratch2 = serial_inp(up, UART_IER) & 0x0f;
1115 serial_outp(up, UART_IER, 0x0F);
1119 scratch3 = serial_inp(up, UART_IER) & 0x0f;
1120 serial_outp(up, UART_IER, scratch);
1121 if (scratch2 != 0 || scratch3 != 0x0F) {
1123 * We failed; there's nothing here
1125 DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
1126 scratch2, scratch3);
1131 save_mcr = serial_in(up, UART_MCR);
1132 save_lcr = serial_in(up, UART_LCR);
1135 * Check to see if a UART is really there. Certain broken
1136 * internal modems based on the Rockwell chipset fail this
1137 * test, because they apparently don't implement the loopback
1138 * test mode. So this test is skipped on the COM 1 through
1139 * COM 4 ports. This *should* be safe, since no board
1140 * manufacturer would be stupid enough to design a board
1141 * that conflicts with COM 1-4 --- we hope!
1143 if (!(up->port.flags & UPF_SKIP_TEST)) {
1144 serial_outp(up, UART_MCR, UART_MCR_LOOP | 0x0A);
1145 status1 = serial_inp(up, UART_MSR) & 0xF0;
1146 serial_outp(up, UART_MCR, save_mcr);
1147 if (status1 != 0x90) {
1148 DEBUG_AUTOCONF("LOOP test failed (%02x) ",
1155 * We're pretty sure there's a port here. Lets find out what
1156 * type of port it is. The IIR top two bits allows us to find
1157 * out if it's 8250 or 16450, 16550, 16550A or later. This
1158 * determines what we test for next.
1160 * We also initialise the EFR (if any) to zero for later. The
1161 * EFR occupies the same register location as the FCR and IIR.
1163 serial_outp(up, UART_LCR, 0xBF);
1164 serial_outp(up, UART_EFR, 0);
1165 serial_outp(up, UART_LCR, 0);
1167 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1168 scratch = serial_in(up, UART_IIR) >> 6;
1170 DEBUG_AUTOCONF("iir=%d ", scratch);
1174 autoconfig_8250(up);
1177 up->port.type = PORT_UNKNOWN;
1180 up->port.type = PORT_16550;
1183 autoconfig_16550a(up);
1187 #ifdef CONFIG_SERIAL_8250_RSA
1189 * Only probe for RSA ports if we got the region.
1191 if (up->port.type == PORT_16550A && probeflags & PROBE_RSA) {
1194 for (i = 0 ; i < probe_rsa_count; ++i) {
1195 if (probe_rsa[i] == up->port.iobase &&
1197 up->port.type = PORT_RSA;
1204 #ifdef CONFIG_SERIAL_8250_AU1X00
1205 /* if access method is AU, it is a 16550 with a quirk */
1206 if (up->port.type == PORT_16550A && up->port.iotype == UPIO_AU)
1207 up->bugs |= UART_BUG_NOMSR;
1210 serial_outp(up, UART_LCR, save_lcr);
1212 if (up->capabilities != uart_config[up->port.type].flags) {
1214 "ttyS%d: detected caps %08x should be %08x\n",
1215 serial_index(&up->port), up->capabilities,
1216 uart_config[up->port.type].flags);
1219 up->port.fifosize = uart_config[up->port.type].fifo_size;
1220 up->capabilities = uart_config[up->port.type].flags;
1221 up->tx_loadsz = uart_config[up->port.type].tx_loadsz;
1223 if (up->port.type == PORT_UNKNOWN)
1229 #ifdef CONFIG_SERIAL_8250_RSA
1230 if (up->port.type == PORT_RSA)
1231 serial_outp(up, UART_RSA_FRR, 0);
1233 serial_outp(up, UART_MCR, save_mcr);
1234 serial8250_clear_fifos(up);
1235 serial_in(up, UART_RX);
1236 if (up->capabilities & UART_CAP_UUE)
1237 serial_outp(up, UART_IER, UART_IER_UUE);
1239 serial_outp(up, UART_IER, 0);
1242 spin_unlock_irqrestore(&up->port.lock, flags);
1243 DEBUG_AUTOCONF("type=%s\n", uart_config[up->port.type].name);
1246 static void autoconfig_irq(struct uart_8250_port *up)
1248 unsigned char save_mcr, save_ier;
1249 unsigned char save_ICP = 0;
1250 unsigned int ICP = 0;
1254 if (up->port.flags & UPF_FOURPORT) {
1255 ICP = (up->port.iobase & 0xfe0) | 0x1f;
1256 save_ICP = inb_p(ICP);
1261 /* forget possible initially masked and pending IRQ */
1262 probe_irq_off(probe_irq_on());
1263 save_mcr = serial_inp(up, UART_MCR);
1264 save_ier = serial_inp(up, UART_IER);
1265 serial_outp(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2);
1267 irqs = probe_irq_on();
1268 serial_outp(up, UART_MCR, 0);
1270 if (up->port.flags & UPF_FOURPORT) {
1271 serial_outp(up, UART_MCR,
1272 UART_MCR_DTR | UART_MCR_RTS);
1274 serial_outp(up, UART_MCR,
1275 UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
1277 serial_outp(up, UART_IER, 0x0f); /* enable all intrs */
1278 (void)serial_inp(up, UART_LSR);
1279 (void)serial_inp(up, UART_RX);
1280 (void)serial_inp(up, UART_IIR);
1281 (void)serial_inp(up, UART_MSR);
1282 serial_outp(up, UART_TX, 0xFF);
1284 irq = probe_irq_off(irqs);
1286 serial_outp(up, UART_MCR, save_mcr);
1287 serial_outp(up, UART_IER, save_ier);
1289 if (up->port.flags & UPF_FOURPORT)
1290 outb_p(save_ICP, ICP);
1292 up->port.irq = (irq > 0) ? irq : 0;
1295 static inline void __stop_tx(struct uart_8250_port *p)
1297 if (p->ier & UART_IER_THRI) {
1298 p->ier &= ~UART_IER_THRI;
1299 serial_out(p, UART_IER, p->ier);
1303 static void serial8250_stop_tx(struct uart_port *port)
1305 struct uart_8250_port *up = (struct uart_8250_port *)port;
1310 * We really want to stop the transmitter from sending.
1312 if (up->port.type == PORT_16C950) {
1313 up->acr |= UART_ACR_TXDIS;
1314 serial_icr_write(up, UART_ACR, up->acr);
1318 static void transmit_chars(struct uart_8250_port *up);
1320 static void serial8250_start_tx(struct uart_port *port)
1322 struct uart_8250_port *up = (struct uart_8250_port *)port;
1324 if (!(up->ier & UART_IER_THRI)) {
1325 up->ier |= UART_IER_THRI;
1326 serial_out(up, UART_IER, up->ier);
1328 if (up->bugs & UART_BUG_TXEN) {
1329 unsigned char lsr, iir;
1330 lsr = serial_in(up, UART_LSR);
1331 up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
1332 iir = serial_in(up, UART_IIR) & 0x0f;
1333 if ((up->port.type == PORT_RM9000) ?
1334 (lsr & UART_LSR_THRE &&
1335 (iir == UART_IIR_NO_INT || iir == UART_IIR_THRI)) :
1336 (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT))
1342 * Re-enable the transmitter if we disabled it.
1344 if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
1345 up->acr &= ~UART_ACR_TXDIS;
1346 serial_icr_write(up, UART_ACR, up->acr);
1350 static void serial8250_stop_rx(struct uart_port *port)
1352 struct uart_8250_port *up = (struct uart_8250_port *)port;
1354 up->ier &= ~UART_IER_RLSI;
1355 up->port.read_status_mask &= ~UART_LSR_DR;
1356 serial_out(up, UART_IER, up->ier);
1359 static void serial8250_enable_ms(struct uart_port *port)
1361 struct uart_8250_port *up = (struct uart_8250_port *)port;
1363 /* no MSR capabilities */
1364 if (up->bugs & UART_BUG_NOMSR)
1367 up->ier |= UART_IER_MSI;
1368 serial_out(up, UART_IER, up->ier);
1372 receive_chars(struct uart_8250_port *up, unsigned int *status)
1374 struct tty_struct *tty = up->port.info->port.tty;
1375 unsigned char ch, lsr = *status;
1376 int max_count = 256;
1380 if (likely(lsr & UART_LSR_DR))
1381 ch = serial_inp(up, UART_RX);
1384 * Intel 82571 has a Serial Over Lan device that will
1385 * set UART_LSR_BI without setting UART_LSR_DR when
1386 * it receives a break. To avoid reading from the
1387 * receive buffer without UART_LSR_DR bit set, we
1388 * just force the read character to be 0
1393 up->port.icount.rx++;
1395 lsr |= up->lsr_saved_flags;
1396 up->lsr_saved_flags = 0;
1398 if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
1400 * For statistics only
1402 if (lsr & UART_LSR_BI) {
1403 lsr &= ~(UART_LSR_FE | UART_LSR_PE);
1404 up->port.icount.brk++;
1406 * We do the SysRQ and SAK checking
1407 * here because otherwise the break
1408 * may get masked by ignore_status_mask
1409 * or read_status_mask.
1411 if (uart_handle_break(&up->port))
1413 } else if (lsr & UART_LSR_PE)
1414 up->port.icount.parity++;
1415 else if (lsr & UART_LSR_FE)
1416 up->port.icount.frame++;
1417 if (lsr & UART_LSR_OE)
1418 up->port.icount.overrun++;
1421 * Mask off conditions which should be ignored.
1423 lsr &= up->port.read_status_mask;
1425 if (lsr & UART_LSR_BI) {
1426 DEBUG_INTR("handling break....");
1428 } else if (lsr & UART_LSR_PE)
1430 else if (lsr & UART_LSR_FE)
1433 if (uart_handle_sysrq_char(&up->port, ch))
1436 uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
1439 lsr = serial_inp(up, UART_LSR);
1440 } while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0));
1441 spin_unlock(&up->port.lock);
1442 tty_flip_buffer_push(tty);
1443 spin_lock(&up->port.lock);
1447 static void transmit_chars(struct uart_8250_port *up)
1449 struct circ_buf *xmit = &up->port.info->xmit;
1452 if (up->port.x_char) {
1453 serial_outp(up, UART_TX, up->port.x_char);
1454 up->port.icount.tx++;
1455 up->port.x_char = 0;
1458 if (uart_tx_stopped(&up->port)) {
1459 serial8250_stop_tx(&up->port);
1462 if (uart_circ_empty(xmit)) {
1467 count = up->tx_loadsz;
1469 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
1470 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
1471 up->port.icount.tx++;
1472 if (uart_circ_empty(xmit))
1474 } while (--count > 0);
1476 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1477 uart_write_wakeup(&up->port);
1479 DEBUG_INTR("THRE...");
1481 if (uart_circ_empty(xmit))
1485 static unsigned int check_modem_status(struct uart_8250_port *up)
1487 unsigned int status = serial_in(up, UART_MSR);
1489 status |= up->msr_saved_flags;
1490 up->msr_saved_flags = 0;
1491 if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
1492 up->port.info != NULL) {
1493 if (status & UART_MSR_TERI)
1494 up->port.icount.rng++;
1495 if (status & UART_MSR_DDSR)
1496 up->port.icount.dsr++;
1497 if (status & UART_MSR_DDCD)
1498 uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
1499 if (status & UART_MSR_DCTS)
1500 uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
1502 wake_up_interruptible(&up->port.info->delta_msr_wait);
1509 * This handles the interrupt from one port.
1511 static void serial8250_handle_port(struct uart_8250_port *up)
1513 unsigned int status;
1514 unsigned long flags;
1516 spin_lock_irqsave(&up->port.lock, flags);
1518 status = serial_inp(up, UART_LSR);
1520 DEBUG_INTR("status = %x...", status);
1522 if (status & (UART_LSR_DR | UART_LSR_BI))
1523 receive_chars(up, &status);
1524 check_modem_status(up);
1525 if (status & UART_LSR_THRE)
1528 spin_unlock_irqrestore(&up->port.lock, flags);
1532 * This is the serial driver's interrupt routine.
1534 * Arjan thinks the old way was overly complex, so it got simplified.
1535 * Alan disagrees, saying that need the complexity to handle the weird
1536 * nature of ISA shared interrupts. (This is a special exception.)
1538 * In order to handle ISA shared interrupts properly, we need to check
1539 * that all ports have been serviced, and therefore the ISA interrupt
1540 * line has been de-asserted.
1542 * This means we need to loop through all ports. checking that they
1543 * don't have an interrupt pending.
1545 static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
1547 struct irq_info *i = dev_id;
1548 struct list_head *l, *end = NULL;
1549 int pass_counter = 0, handled = 0;
1551 DEBUG_INTR("serial8250_interrupt(%d)...", irq);
1553 spin_lock(&i->lock);
1557 struct uart_8250_port *up;
1560 up = list_entry(l, struct uart_8250_port, list);
1562 iir = serial_in(up, UART_IIR);
1563 if (!(iir & UART_IIR_NO_INT)) {
1564 serial8250_handle_port(up);
1569 } else if (up->port.iotype == UPIO_DWAPB &&
1570 (iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
1571 /* The DesignWare APB UART has an Busy Detect (0x07)
1572 * interrupt meaning an LCR write attempt occured while the
1573 * UART was busy. The interrupt must be cleared by reading
1574 * the UART status register (USR) and the LCR re-written. */
1575 unsigned int status;
1576 status = *(volatile u32 *)up->port.private_data;
1577 serial_out(up, UART_LCR, up->lcr);
1582 } else if (end == NULL)
1587 if (l == i->head && pass_counter++ > PASS_LIMIT) {
1588 /* If we hit this, we're dead. */
1589 printk(KERN_ERR "serial8250: too much work for "
1595 spin_unlock(&i->lock);
1597 DEBUG_INTR("end.\n");
1599 return IRQ_RETVAL(handled);
1603 * To support ISA shared interrupts, we need to have one interrupt
1604 * handler that ensures that the IRQ line has been deasserted
1605 * before returning. Failing to do this will result in the IRQ
1606 * line being stuck active, and, since ISA irqs are edge triggered,
1607 * no more IRQs will be seen.
1609 static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up)
1611 spin_lock_irq(&i->lock);
1613 if (!list_empty(i->head)) {
1614 if (i->head == &up->list)
1615 i->head = i->head->next;
1616 list_del(&up->list);
1618 BUG_ON(i->head != &up->list);
1621 spin_unlock_irq(&i->lock);
1622 /* List empty so throw away the hash node */
1623 if (i->head == NULL) {
1624 hlist_del(&i->node);
1629 static int serial_link_irq_chain(struct uart_8250_port *up)
1631 struct hlist_head *h;
1632 struct hlist_node *n;
1634 int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0;
1636 mutex_lock(&hash_mutex);
1638 h = &irq_lists[up->port.irq % NR_IRQ_HASH];
1640 hlist_for_each(n, h) {
1641 i = hlist_entry(n, struct irq_info, node);
1642 if (i->irq == up->port.irq)
1647 i = kzalloc(sizeof(struct irq_info), GFP_KERNEL);
1649 mutex_unlock(&hash_mutex);
1652 spin_lock_init(&i->lock);
1653 i->irq = up->port.irq;
1654 hlist_add_head(&i->node, h);
1656 mutex_unlock(&hash_mutex);
1658 spin_lock_irq(&i->lock);
1661 list_add(&up->list, i->head);
1662 spin_unlock_irq(&i->lock);
1666 INIT_LIST_HEAD(&up->list);
1667 i->head = &up->list;
1668 spin_unlock_irq(&i->lock);
1670 ret = request_irq(up->port.irq, serial8250_interrupt,
1671 irq_flags, "serial", i);
1673 serial_do_unlink(i, up);
1679 static void serial_unlink_irq_chain(struct uart_8250_port *up)
1682 struct hlist_node *n;
1683 struct hlist_head *h;
1685 mutex_lock(&hash_mutex);
1687 h = &irq_lists[up->port.irq % NR_IRQ_HASH];
1689 hlist_for_each(n, h) {
1690 i = hlist_entry(n, struct irq_info, node);
1691 if (i->irq == up->port.irq)
1696 BUG_ON(i->head == NULL);
1698 if (list_empty(i->head))
1699 free_irq(up->port.irq, i);
1701 serial_do_unlink(i, up);
1702 mutex_unlock(&hash_mutex);
1705 /* Base timer interval for polling */
1706 static inline int poll_timeout(int timeout)
1708 return timeout > 6 ? (timeout / 2 - 2) : 1;
1712 * This function is used to handle ports that do not have an
1713 * interrupt. This doesn't work very well for 16450's, but gives
1714 * barely passable results for a 16550A. (Although at the expense
1715 * of much CPU overhead).
1717 static void serial8250_timeout(unsigned long data)
1719 struct uart_8250_port *up = (struct uart_8250_port *)data;
1722 iir = serial_in(up, UART_IIR);
1723 if (!(iir & UART_IIR_NO_INT))
1724 serial8250_handle_port(up);
1725 mod_timer(&up->timer, jiffies + poll_timeout(up->port.timeout));
1728 static void serial8250_backup_timeout(unsigned long data)
1730 struct uart_8250_port *up = (struct uart_8250_port *)data;
1731 unsigned int iir, ier = 0, lsr;
1732 unsigned long flags;
1735 * Must disable interrupts or else we risk racing with the interrupt
1738 if (is_real_interrupt(up->port.irq)) {
1739 ier = serial_in(up, UART_IER);
1740 serial_out(up, UART_IER, 0);
1743 iir = serial_in(up, UART_IIR);
1746 * This should be a safe test for anyone who doesn't trust the
1747 * IIR bits on their UART, but it's specifically designed for
1748 * the "Diva" UART used on the management processor on many HP
1749 * ia64 and parisc boxes.
1751 spin_lock_irqsave(&up->port.lock, flags);
1752 lsr = serial_in(up, UART_LSR);
1753 up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
1754 spin_unlock_irqrestore(&up->port.lock, flags);
1755 if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
1756 (!uart_circ_empty(&up->port.info->xmit) || up->port.x_char) &&
1757 (lsr & UART_LSR_THRE)) {
1758 iir &= ~(UART_IIR_ID | UART_IIR_NO_INT);
1759 iir |= UART_IIR_THRI;
1762 if (!(iir & UART_IIR_NO_INT))
1763 serial8250_handle_port(up);
1765 if (is_real_interrupt(up->port.irq))
1766 serial_out(up, UART_IER, ier);
1768 /* Standard timer interval plus 0.2s to keep the port running */
1769 mod_timer(&up->timer,
1770 jiffies + poll_timeout(up->port.timeout) + HZ / 5);
1773 static unsigned int serial8250_tx_empty(struct uart_port *port)
1775 struct uart_8250_port *up = (struct uart_8250_port *)port;
1776 unsigned long flags;
1779 spin_lock_irqsave(&up->port.lock, flags);
1780 lsr = serial_in(up, UART_LSR);
1781 up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
1782 spin_unlock_irqrestore(&up->port.lock, flags);
1784 return lsr & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
1787 static unsigned int serial8250_get_mctrl(struct uart_port *port)
1789 struct uart_8250_port *up = (struct uart_8250_port *)port;
1790 unsigned int status;
1793 status = check_modem_status(up);
1796 if (status & UART_MSR_DCD)
1798 if (status & UART_MSR_RI)
1800 if (status & UART_MSR_DSR)
1802 if (status & UART_MSR_CTS)
1807 static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
1809 struct uart_8250_port *up = (struct uart_8250_port *)port;
1810 unsigned char mcr = 0;
1812 if (mctrl & TIOCM_RTS)
1813 mcr |= UART_MCR_RTS;
1814 if (mctrl & TIOCM_DTR)
1815 mcr |= UART_MCR_DTR;
1816 if (mctrl & TIOCM_OUT1)
1817 mcr |= UART_MCR_OUT1;
1818 if (mctrl & TIOCM_OUT2)
1819 mcr |= UART_MCR_OUT2;
1820 if (mctrl & TIOCM_LOOP)
1821 mcr |= UART_MCR_LOOP;
1823 mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
1825 serial_out(up, UART_MCR, mcr);
1828 static void serial8250_break_ctl(struct uart_port *port, int break_state)
1830 struct uart_8250_port *up = (struct uart_8250_port *)port;
1831 unsigned long flags;
1833 spin_lock_irqsave(&up->port.lock, flags);
1834 if (break_state == -1)
1835 up->lcr |= UART_LCR_SBC;
1837 up->lcr &= ~UART_LCR_SBC;
1838 serial_out(up, UART_LCR, up->lcr);
1839 spin_unlock_irqrestore(&up->port.lock, flags);
1842 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
1845 * Wait for transmitter & holding register to empty
1847 static void wait_for_xmitr(struct uart_8250_port *up, int bits)
1849 unsigned int status, tmout = 10000;
1851 /* Wait up to 10ms for the character(s) to be sent. */
1853 status = serial_in(up, UART_LSR);
1855 up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
1860 } while ((status & bits) != bits);
1862 /* Wait up to 1s for flow control if necessary */
1863 if (up->port.flags & UPF_CONS_FLOW) {
1865 for (tmout = 1000000; tmout; tmout--) {
1866 unsigned int msr = serial_in(up, UART_MSR);
1867 up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
1868 if (msr & UART_MSR_CTS)
1871 touch_nmi_watchdog();
1876 #ifdef CONFIG_CONSOLE_POLL
1878 * Console polling routines for writing and reading from the uart while
1879 * in an interrupt or debug context.
1882 static int serial8250_get_poll_char(struct uart_port *port)
1884 struct uart_8250_port *up = (struct uart_8250_port *)port;
1885 unsigned char lsr = serial_inp(up, UART_LSR);
1887 while (!(lsr & UART_LSR_DR))
1888 lsr = serial_inp(up, UART_LSR);
1890 return serial_inp(up, UART_RX);
1894 static void serial8250_put_poll_char(struct uart_port *port,
1898 struct uart_8250_port *up = (struct uart_8250_port *)port;
1901 * First save the IER then disable the interrupts
1903 ier = serial_in(up, UART_IER);
1904 if (up->capabilities & UART_CAP_UUE)
1905 serial_out(up, UART_IER, UART_IER_UUE);
1907 serial_out(up, UART_IER, 0);
1909 wait_for_xmitr(up, BOTH_EMPTY);
1911 * Send the character out.
1912 * If a LF, also do CR...
1914 serial_out(up, UART_TX, c);
1916 wait_for_xmitr(up, BOTH_EMPTY);
1917 serial_out(up, UART_TX, 13);
1921 * Finally, wait for transmitter to become empty
1922 * and restore the IER
1924 wait_for_xmitr(up, BOTH_EMPTY);
1925 serial_out(up, UART_IER, ier);
1928 #endif /* CONFIG_CONSOLE_POLL */
1930 static int serial8250_startup(struct uart_port *port)
1932 struct uart_8250_port *up = (struct uart_8250_port *)port;
1933 unsigned long flags;
1934 unsigned char lsr, iir;
1937 up->capabilities = uart_config[up->port.type].flags;
1940 if (up->port.type == PORT_16C950) {
1941 /* Wake up and initialize UART */
1943 serial_outp(up, UART_LCR, 0xBF);
1944 serial_outp(up, UART_EFR, UART_EFR_ECB);
1945 serial_outp(up, UART_IER, 0);
1946 serial_outp(up, UART_LCR, 0);
1947 serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
1948 serial_outp(up, UART_LCR, 0xBF);
1949 serial_outp(up, UART_EFR, UART_EFR_ECB);
1950 serial_outp(up, UART_LCR, 0);
1953 #ifdef CONFIG_SERIAL_8250_RSA
1955 * If this is an RSA port, see if we can kick it up to the
1956 * higher speed clock.
1962 * Clear the FIFO buffers and disable them.
1963 * (they will be reenabled in set_termios())
1965 serial8250_clear_fifos(up);
1968 * Clear the interrupt registers.
1970 (void) serial_inp(up, UART_LSR);
1971 (void) serial_inp(up, UART_RX);
1972 (void) serial_inp(up, UART_IIR);
1973 (void) serial_inp(up, UART_MSR);
1976 * At this point, there's no way the LSR could still be 0xff;
1977 * if it is, then bail out, because there's likely no UART
1980 if (!(up->port.flags & UPF_BUGGY_UART) &&
1981 (serial_inp(up, UART_LSR) == 0xff)) {
1982 printk(KERN_INFO "ttyS%d: LSR safety check engaged!\n",
1983 serial_index(&up->port));
1988 * For a XR16C850, we need to set the trigger levels
1990 if (up->port.type == PORT_16850) {
1993 serial_outp(up, UART_LCR, 0xbf);
1995 fctr = serial_inp(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
1996 serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_RX);
1997 serial_outp(up, UART_TRG, UART_TRG_96);
1998 serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_TX);
1999 serial_outp(up, UART_TRG, UART_TRG_96);
2001 serial_outp(up, UART_LCR, 0);
2004 if (is_real_interrupt(up->port.irq)) {
2007 * Test for UARTs that do not reassert THRE when the
2008 * transmitter is idle and the interrupt has already
2009 * been cleared. Real 16550s should always reassert
2010 * this interrupt whenever the transmitter is idle and
2011 * the interrupt is enabled. Delays are necessary to
2012 * allow register changes to become visible.
2014 spin_lock_irqsave(&up->port.lock, flags);
2015 if (up->port.flags & UPF_SHARE_IRQ)
2016 disable_irq_nosync(up->port.irq);
2018 wait_for_xmitr(up, UART_LSR_THRE);
2019 serial_out_sync(up, UART_IER, UART_IER_THRI);
2020 udelay(1); /* allow THRE to set */
2021 iir1 = serial_in(up, UART_IIR);
2022 serial_out(up, UART_IER, 0);
2023 serial_out_sync(up, UART_IER, UART_IER_THRI);
2024 udelay(1); /* allow a working UART time to re-assert THRE */
2025 iir = serial_in(up, UART_IIR);
2026 serial_out(up, UART_IER, 0);
2028 if (up->port.flags & UPF_SHARE_IRQ)
2029 enable_irq(up->port.irq);
2030 spin_unlock_irqrestore(&up->port.lock, flags);
2033 * If the interrupt is not reasserted, setup a timer to
2034 * kick the UART on a regular basis.
2036 if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) {
2037 up->bugs |= UART_BUG_THRE;
2038 pr_debug("ttyS%d - using backup timer\n",
2039 serial_index(port));
2044 * The above check will only give an accurate result the first time
2045 * the port is opened so this value needs to be preserved.
2047 if (up->bugs & UART_BUG_THRE) {
2048 up->timer.function = serial8250_backup_timeout;
2049 up->timer.data = (unsigned long)up;
2050 mod_timer(&up->timer, jiffies +
2051 poll_timeout(up->port.timeout) + HZ / 5);
2055 * If the "interrupt" for this port doesn't correspond with any
2056 * hardware interrupt, we use a timer-based system. The original
2057 * driver used to do this with IRQ0.
2059 if (!is_real_interrupt(up->port.irq)) {
2060 up->timer.data = (unsigned long)up;
2061 mod_timer(&up->timer, jiffies + poll_timeout(up->port.timeout));
2063 retval = serial_link_irq_chain(up);
2069 * Now, initialize the UART
2071 serial_outp(up, UART_LCR, UART_LCR_WLEN8);
2073 spin_lock_irqsave(&up->port.lock, flags);
2074 if (up->port.flags & UPF_FOURPORT) {
2075 if (!is_real_interrupt(up->port.irq))
2076 up->port.mctrl |= TIOCM_OUT1;
2079 * Most PC uarts need OUT2 raised to enable interrupts.
2081 if (is_real_interrupt(up->port.irq))
2082 up->port.mctrl |= TIOCM_OUT2;
2084 serial8250_set_mctrl(&up->port, up->port.mctrl);
2086 /* Serial over Lan (SoL) hack:
2087 Intel 8257x Gigabit ethernet chips have a
2088 16550 emulation, to be used for Serial Over Lan.
2089 Those chips take a longer time than a normal
2090 serial device to signalize that a transmission
2091 data was queued. Due to that, the above test generally
2092 fails. One solution would be to delay the reading of
2093 iir. However, this is not reliable, since the timeout
2094 is variable. So, let's just don't test if we receive
2095 TX irq. This way, we'll never enable UART_BUG_TXEN.
2097 if (up->port.flags & UPF_NO_TXEN_TEST)
2098 goto dont_test_tx_en;
2101 * Do a quick test to see if we receive an
2102 * interrupt when we enable the TX irq.
2104 serial_outp(up, UART_IER, UART_IER_THRI);
2105 lsr = serial_in(up, UART_LSR);
2106 iir = serial_in(up, UART_IIR);
2107 serial_outp(up, UART_IER, 0);
2109 if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
2110 if (!(up->bugs & UART_BUG_TXEN)) {
2111 up->bugs |= UART_BUG_TXEN;
2112 pr_debug("ttyS%d - enabling bad tx status workarounds\n",
2113 serial_index(port));
2116 up->bugs &= ~UART_BUG_TXEN;
2120 spin_unlock_irqrestore(&up->port.lock, flags);
2123 * Clear the interrupt registers again for luck, and clear the
2124 * saved flags to avoid getting false values from polling
2125 * routines or the previous session.
2127 serial_inp(up, UART_LSR);
2128 serial_inp(up, UART_RX);
2129 serial_inp(up, UART_IIR);
2130 serial_inp(up, UART_MSR);
2131 up->lsr_saved_flags = 0;
2132 up->msr_saved_flags = 0;
2135 * Finally, enable interrupts. Note: Modem status interrupts
2136 * are set via set_termios(), which will be occurring imminently
2137 * anyway, so we don't enable them here.
2139 up->ier = UART_IER_RLSI | UART_IER_RDI;
2140 serial_outp(up, UART_IER, up->ier);
2142 if (up->port.flags & UPF_FOURPORT) {
2145 * Enable interrupts on the AST Fourport board
2147 icp = (up->port.iobase & 0xfe0) | 0x01f;
2155 static void serial8250_shutdown(struct uart_port *port)
2157 struct uart_8250_port *up = (struct uart_8250_port *)port;
2158 unsigned long flags;
2161 * Disable interrupts from this port
2164 serial_outp(up, UART_IER, 0);
2166 spin_lock_irqsave(&up->port.lock, flags);
2167 if (up->port.flags & UPF_FOURPORT) {
2168 /* reset interrupts on the AST Fourport board */
2169 inb((up->port.iobase & 0xfe0) | 0x1f);
2170 up->port.mctrl |= TIOCM_OUT1;
2172 up->port.mctrl &= ~TIOCM_OUT2;
2174 serial8250_set_mctrl(&up->port, up->port.mctrl);
2175 spin_unlock_irqrestore(&up->port.lock, flags);
2178 * Disable break condition and FIFOs
2180 serial_out(up, UART_LCR, serial_inp(up, UART_LCR) & ~UART_LCR_SBC);
2181 serial8250_clear_fifos(up);
2183 #ifdef CONFIG_SERIAL_8250_RSA
2185 * Reset the RSA board back to 115kbps compat mode.
2191 * Read data port to reset things, and then unlink from
2194 (void) serial_in(up, UART_RX);
2196 del_timer_sync(&up->timer);
2197 up->timer.function = serial8250_timeout;
2198 if (is_real_interrupt(up->port.irq))
2199 serial_unlink_irq_chain(up);
2202 static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud)
2207 * Handle magic divisors for baud rates above baud_base on
2208 * SMSC SuperIO chips.
2210 if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
2211 baud == (port->uartclk/4))
2213 else if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
2214 baud == (port->uartclk/8))
2217 quot = uart_get_divisor(port, baud);
2223 serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
2224 struct ktermios *old)
2226 struct uart_8250_port *up = (struct uart_8250_port *)port;
2227 unsigned char cval, fcr = 0;
2228 unsigned long flags;
2229 unsigned int baud, quot;
2231 switch (termios->c_cflag & CSIZE) {
2233 cval = UART_LCR_WLEN5;
2236 cval = UART_LCR_WLEN6;
2239 cval = UART_LCR_WLEN7;
2243 cval = UART_LCR_WLEN8;
2247 if (termios->c_cflag & CSTOPB)
2248 cval |= UART_LCR_STOP;
2249 if (termios->c_cflag & PARENB)
2250 cval |= UART_LCR_PARITY;
2251 if (!(termios->c_cflag & PARODD))
2252 cval |= UART_LCR_EPAR;
2254 if (termios->c_cflag & CMSPAR)
2255 cval |= UART_LCR_SPAR;
2259 * Ask the core to calculate the divisor for us.
2261 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
2262 quot = serial8250_get_divisor(port, baud);
2265 * Oxford Semi 952 rev B workaround
2267 if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
2270 if (up->capabilities & UART_CAP_FIFO && up->port.fifosize > 1) {
2272 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
2274 fcr = uart_config[up->port.type].fcr;
2278 * MCR-based auto flow control. When AFE is enabled, RTS will be
2279 * deasserted when the receive FIFO contains more characters than
2280 * the trigger, or the MCR RTS bit is cleared. In the case where
2281 * the remote UART is not using CTS auto flow control, we must
2282 * have sufficient FIFO entries for the latency of the remote
2283 * UART to respond. IOW, at least 32 bytes of FIFO.
2285 if (up->capabilities & UART_CAP_AFE && up->port.fifosize >= 32) {
2286 up->mcr &= ~UART_MCR_AFE;
2287 if (termios->c_cflag & CRTSCTS)
2288 up->mcr |= UART_MCR_AFE;
2292 * Ok, we're now changing the port state. Do it with
2293 * interrupts disabled.
2295 spin_lock_irqsave(&up->port.lock, flags);
2298 * Update the per-port timeout.
2300 uart_update_timeout(port, termios->c_cflag, baud);
2302 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
2303 if (termios->c_iflag & INPCK)
2304 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
2305 if (termios->c_iflag & (BRKINT | PARMRK))
2306 up->port.read_status_mask |= UART_LSR_BI;
2309 * Characteres to ignore
2311 up->port.ignore_status_mask = 0;
2312 if (termios->c_iflag & IGNPAR)
2313 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
2314 if (termios->c_iflag & IGNBRK) {
2315 up->port.ignore_status_mask |= UART_LSR_BI;
2317 * If we're ignoring parity and break indicators,
2318 * ignore overruns too (for real raw support).
2320 if (termios->c_iflag & IGNPAR)
2321 up->port.ignore_status_mask |= UART_LSR_OE;
2325 * ignore all characters if CREAD is not set
2327 if ((termios->c_cflag & CREAD) == 0)
2328 up->port.ignore_status_mask |= UART_LSR_DR;
2331 * CTS flow control flag and modem status interrupts
2333 up->ier &= ~UART_IER_MSI;
2334 if (!(up->bugs & UART_BUG_NOMSR) &&
2335 UART_ENABLE_MS(&up->port, termios->c_cflag))
2336 up->ier |= UART_IER_MSI;
2337 if (up->capabilities & UART_CAP_UUE)
2338 up->ier |= UART_IER_UUE | UART_IER_RTOIE;
2340 serial_out(up, UART_IER, up->ier);
2342 if (up->capabilities & UART_CAP_EFR) {
2343 unsigned char efr = 0;
2345 * TI16C752/Startech hardware flow control. FIXME:
2346 * - TI16C752 requires control thresholds to be set.
2347 * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
2349 if (termios->c_cflag & CRTSCTS)
2350 efr |= UART_EFR_CTS;
2352 serial_outp(up, UART_LCR, 0xBF);
2353 serial_outp(up, UART_EFR, efr);
2356 #ifdef CONFIG_ARCH_OMAP
2357 /* Workaround to enable 115200 baud on OMAP1510 internal ports */
2358 if (cpu_is_omap1510() && is_omap_port(up)) {
2359 if (baud == 115200) {
2361 serial_out(up, UART_OMAP_OSC_12M_SEL, 1);
2363 serial_out(up, UART_OMAP_OSC_12M_SEL, 0);
2367 if (up->capabilities & UART_NATSEMI) {
2368 /* Switch to bank 2 not bank 1, to avoid resetting EXCR2 */
2369 serial_outp(up, UART_LCR, 0xe0);
2371 serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
2374 serial_dl_write(up, quot);
2377 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
2378 * is written without DLAB set, this mode will be disabled.
2380 if (up->port.type == PORT_16750)
2381 serial_outp(up, UART_FCR, fcr);
2383 serial_outp(up, UART_LCR, cval); /* reset DLAB */
2384 up->lcr = cval; /* Save LCR */
2385 if (up->port.type != PORT_16750) {
2386 if (fcr & UART_FCR_ENABLE_FIFO) {
2387 /* emulated UARTs (Lucent Venus 167x) need two steps */
2388 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
2390 serial_outp(up, UART_FCR, fcr); /* set fcr */
2392 serial8250_set_mctrl(&up->port, up->port.mctrl);
2393 spin_unlock_irqrestore(&up->port.lock, flags);
2394 /* Don't rewrite B0 */
2395 if (tty_termios_baud_rate(termios))
2396 tty_termios_encode_baud_rate(termios, baud, baud);
2400 serial8250_pm(struct uart_port *port, unsigned int state,
2401 unsigned int oldstate)
2403 struct uart_8250_port *p = (struct uart_8250_port *)port;
2405 serial8250_set_sleep(p, state != 0);
2408 p->pm(port, state, oldstate);
2411 static unsigned int serial8250_port_size(struct uart_8250_port *pt)
2413 if (pt->port.iotype == UPIO_AU)
2415 #ifdef CONFIG_ARCH_OMAP
2416 if (is_omap_port(pt))
2417 return 0x16 << pt->port.regshift;
2419 return 8 << pt->port.regshift;
2423 * Resource handling.
2425 static int serial8250_request_std_resource(struct uart_8250_port *up)
2427 unsigned int size = serial8250_port_size(up);
2430 switch (up->port.iotype) {
2436 if (!up->port.mapbase)
2439 if (!request_mem_region(up->port.mapbase, size, "serial")) {
2444 if (up->port.flags & UPF_IOREMAP) {
2445 up->port.membase = ioremap_nocache(up->port.mapbase,
2447 if (!up->port.membase) {
2448 release_mem_region(up->port.mapbase, size);
2456 if (!request_region(up->port.iobase, size, "serial"))
2463 static void serial8250_release_std_resource(struct uart_8250_port *up)
2465 unsigned int size = serial8250_port_size(up);
2467 switch (up->port.iotype) {
2473 if (!up->port.mapbase)
2476 if (up->port.flags & UPF_IOREMAP) {
2477 iounmap(up->port.membase);
2478 up->port.membase = NULL;
2481 release_mem_region(up->port.mapbase, size);
2486 release_region(up->port.iobase, size);
2491 static int serial8250_request_rsa_resource(struct uart_8250_port *up)
2493 unsigned long start = UART_RSA_BASE << up->port.regshift;
2494 unsigned int size = 8 << up->port.regshift;
2497 switch (up->port.iotype) {
2500 start += up->port.iobase;
2501 if (request_region(start, size, "serial-rsa"))
2511 static void serial8250_release_rsa_resource(struct uart_8250_port *up)
2513 unsigned long offset = UART_RSA_BASE << up->port.regshift;
2514 unsigned int size = 8 << up->port.regshift;
2516 switch (up->port.iotype) {
2519 release_region(up->port.iobase + offset, size);
2524 static void serial8250_release_port(struct uart_port *port)
2526 struct uart_8250_port *up = (struct uart_8250_port *)port;
2528 serial8250_release_std_resource(up);
2529 if (up->port.type == PORT_RSA)
2530 serial8250_release_rsa_resource(up);
2533 static int serial8250_request_port(struct uart_port *port)
2535 struct uart_8250_port *up = (struct uart_8250_port *)port;
2538 ret = serial8250_request_std_resource(up);
2539 if (ret == 0 && up->port.type == PORT_RSA) {
2540 ret = serial8250_request_rsa_resource(up);
2542 serial8250_release_std_resource(up);
2548 static void serial8250_config_port(struct uart_port *port, int flags)
2550 struct uart_8250_port *up = (struct uart_8250_port *)port;
2551 int probeflags = PROBE_ANY;
2555 * Find the region that we can probe for. This in turn
2556 * tells us whether we can probe for the type of port.
2558 ret = serial8250_request_std_resource(up);
2562 ret = serial8250_request_rsa_resource(up);
2564 probeflags &= ~PROBE_RSA;
2566 if (flags & UART_CONFIG_TYPE)
2567 autoconfig(up, probeflags);
2568 if (up->port.type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
2571 if (up->port.type != PORT_RSA && probeflags & PROBE_RSA)
2572 serial8250_release_rsa_resource(up);
2573 if (up->port.type == PORT_UNKNOWN)
2574 serial8250_release_std_resource(up);
2578 serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
2580 if (ser->irq >= nr_irqs || ser->irq < 0 ||
2581 ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
2582 ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
2583 ser->type == PORT_STARTECH)
2589 serial8250_type(struct uart_port *port)
2591 int type = port->type;
2593 if (type >= ARRAY_SIZE(uart_config))
2595 return uart_config[type].name;
2598 static struct uart_ops serial8250_pops = {
2599 .tx_empty = serial8250_tx_empty,
2600 .set_mctrl = serial8250_set_mctrl,
2601 .get_mctrl = serial8250_get_mctrl,
2602 .stop_tx = serial8250_stop_tx,
2603 .start_tx = serial8250_start_tx,
2604 .stop_rx = serial8250_stop_rx,
2605 .enable_ms = serial8250_enable_ms,
2606 .break_ctl = serial8250_break_ctl,
2607 .startup = serial8250_startup,
2608 .shutdown = serial8250_shutdown,
2609 .set_termios = serial8250_set_termios,
2610 .pm = serial8250_pm,
2611 .type = serial8250_type,
2612 .release_port = serial8250_release_port,
2613 .request_port = serial8250_request_port,
2614 .config_port = serial8250_config_port,
2615 .verify_port = serial8250_verify_port,
2616 #ifdef CONFIG_CONSOLE_POLL
2617 .poll_get_char = serial8250_get_poll_char,
2618 .poll_put_char = serial8250_put_poll_char,
2622 static struct uart_8250_port serial8250_ports[UART_NR];
2624 static void __init serial8250_isa_init_ports(void)
2626 struct uart_8250_port *up;
2627 static int first = 1;
2634 for (i = 0; i < nr_uarts; i++) {
2635 struct uart_8250_port *up = &serial8250_ports[i];
2638 spin_lock_init(&up->port.lock);
2640 init_timer(&up->timer);
2641 up->timer.function = serial8250_timeout;
2644 * ALPHA_KLUDGE_MCR needs to be killed.
2646 up->mcr_mask = ~ALPHA_KLUDGE_MCR;
2647 up->mcr_force = ALPHA_KLUDGE_MCR;
2649 up->port.ops = &serial8250_pops;
2652 for (i = 0, up = serial8250_ports;
2653 i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
2655 up->port.iobase = old_serial_port[i].port;
2656 up->port.irq = irq_canonicalize(old_serial_port[i].irq);
2657 up->port.uartclk = old_serial_port[i].baud_base * 16;
2658 up->port.flags = old_serial_port[i].flags;
2659 up->port.hub6 = old_serial_port[i].hub6;
2660 up->port.membase = old_serial_port[i].iomem_base;
2661 up->port.iotype = old_serial_port[i].io_type;
2662 up->port.regshift = old_serial_port[i].iomem_reg_shift;
2663 set_io_from_upio(&up->port);
2665 up->port.flags |= UPF_SHARE_IRQ;
2670 serial8250_register_ports(struct uart_driver *drv, struct device *dev)
2674 serial8250_isa_init_ports();
2676 for (i = 0; i < nr_uarts; i++) {
2677 struct uart_8250_port *up = &serial8250_ports[i];
2680 uart_add_one_port(drv, &up->port);
2684 #ifdef CONFIG_SERIAL_8250_CONSOLE
2686 static void serial8250_console_putchar(struct uart_port *port, int ch)
2688 struct uart_8250_port *up = (struct uart_8250_port *)port;
2690 wait_for_xmitr(up, UART_LSR_THRE);
2691 serial_out(up, UART_TX, ch);
2695 * Print a string to the serial port trying not to disturb
2696 * any possible real use of the port...
2698 * The console_lock must be held when we get here.
2701 serial8250_console_write(struct console *co, const char *s, unsigned int count)
2703 struct uart_8250_port *up = &serial8250_ports[co->index];
2704 unsigned long flags;
2708 touch_nmi_watchdog();
2710 local_irq_save(flags);
2711 if (up->port.sysrq) {
2712 /* serial8250_handle_port() already took the lock */
2714 } else if (oops_in_progress) {
2715 locked = spin_trylock(&up->port.lock);
2717 spin_lock(&up->port.lock);
2720 * First save the IER then disable the interrupts
2722 ier = serial_in(up, UART_IER);
2724 if (up->capabilities & UART_CAP_UUE)
2725 serial_out(up, UART_IER, UART_IER_UUE);
2727 serial_out(up, UART_IER, 0);
2729 uart_console_write(&up->port, s, count, serial8250_console_putchar);
2732 * Finally, wait for transmitter to become empty
2733 * and restore the IER
2735 wait_for_xmitr(up, BOTH_EMPTY);
2736 serial_out(up, UART_IER, ier);
2739 * The receive handling will happen properly because the
2740 * receive ready bit will still be set; it is not cleared
2741 * on read. However, modem control will not, we must
2742 * call it if we have saved something in the saved flags
2743 * while processing with interrupts off.
2745 if (up->msr_saved_flags)
2746 check_modem_status(up);
2749 spin_unlock(&up->port.lock);
2750 local_irq_restore(flags);
2753 static int __init serial8250_console_setup(struct console *co, char *options)
2755 struct uart_port *port;
2762 * Check whether an invalid uart number has been specified, and
2763 * if so, search for the first available port that does have
2766 if (co->index >= nr_uarts)
2768 port = &serial8250_ports[co->index].port;
2769 if (!port->iobase && !port->membase)
2773 uart_parse_options(options, &baud, &parity, &bits, &flow);
2775 return uart_set_options(port, co, baud, parity, bits, flow);
2778 static int serial8250_console_early_setup(void)
2780 return serial8250_find_port_for_earlycon();
2783 static struct console serial8250_console = {
2785 .write = serial8250_console_write,
2786 .device = uart_console_device,
2787 .setup = serial8250_console_setup,
2788 .early_setup = serial8250_console_early_setup,
2789 .flags = CON_PRINTBUFFER,
2791 .data = &serial8250_reg,
2794 static int __init serial8250_console_init(void)
2796 if (nr_uarts > UART_NR)
2799 serial8250_isa_init_ports();
2800 register_console(&serial8250_console);
2803 console_initcall(serial8250_console_init);
2805 int serial8250_find_port(struct uart_port *p)
2808 struct uart_port *port;
2810 for (line = 0; line < nr_uarts; line++) {
2811 port = &serial8250_ports[line].port;
2812 if (uart_match_port(p, port))
2818 #define SERIAL8250_CONSOLE &serial8250_console
2820 #define SERIAL8250_CONSOLE NULL
2823 static struct uart_driver serial8250_reg = {
2824 .owner = THIS_MODULE,
2825 .driver_name = "serial",
2829 .cons = SERIAL8250_CONSOLE,
2833 * early_serial_setup - early registration for 8250 ports
2835 * Setup an 8250 port structure prior to console initialisation. Use
2836 * after console initialisation will cause undefined behaviour.
2838 int __init early_serial_setup(struct uart_port *port)
2840 struct uart_port *p;
2842 if (port->line >= ARRAY_SIZE(serial8250_ports))
2845 serial8250_isa_init_ports();
2846 p = &serial8250_ports[port->line].port;
2847 p->iobase = port->iobase;
2848 p->membase = port->membase;
2850 p->uartclk = port->uartclk;
2851 p->fifosize = port->fifosize;
2852 p->regshift = port->regshift;
2853 p->iotype = port->iotype;
2854 p->flags = port->flags;
2855 p->mapbase = port->mapbase;
2856 p->private_data = port->private_data;
2857 p->type = port->type;
2858 p->line = port->line;
2860 set_io_from_upio(p);
2861 if (port->serial_in)
2862 p->serial_in = port->serial_in;
2863 if (port->serial_out)
2864 p->serial_out = port->serial_out;
2870 * serial8250_suspend_port - suspend one serial port
2871 * @line: serial line number
2873 * Suspend one serial port.
2875 void serial8250_suspend_port(int line)
2877 uart_suspend_port(&serial8250_reg, &serial8250_ports[line].port);
2881 * serial8250_resume_port - resume one serial port
2882 * @line: serial line number
2884 * Resume one serial port.
2886 void serial8250_resume_port(int line)
2888 struct uart_8250_port *up = &serial8250_ports[line];
2890 if (up->capabilities & UART_NATSEMI) {
2893 /* Ensure it's still in high speed mode */
2894 serial_outp(up, UART_LCR, 0xE0);
2896 tmp = serial_in(up, 0x04); /* EXCR2 */
2897 tmp &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
2898 tmp |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
2899 serial_outp(up, 0x04, tmp);
2901 serial_outp(up, UART_LCR, 0);
2903 uart_resume_port(&serial8250_reg, &up->port);
2907 * Register a set of serial devices attached to a platform device. The
2908 * list is terminated with a zero flags entry, which means we expect
2909 * all entries to have at least UPF_BOOT_AUTOCONF set.
2911 static int __devinit serial8250_probe(struct platform_device *dev)
2913 struct plat_serial8250_port *p = dev->dev.platform_data;
2914 struct uart_port port;
2917 memset(&port, 0, sizeof(struct uart_port));
2919 for (i = 0; p && p->flags != 0; p++, i++) {
2920 port.iobase = p->iobase;
2921 port.membase = p->membase;
2923 port.uartclk = p->uartclk;
2924 port.regshift = p->regshift;
2925 port.iotype = p->iotype;
2926 port.flags = p->flags;
2927 port.mapbase = p->mapbase;
2928 port.hub6 = p->hub6;
2929 port.private_data = p->private_data;
2930 port.type = p->type;
2931 port.serial_in = p->serial_in;
2932 port.serial_out = p->serial_out;
2933 port.dev = &dev->dev;
2935 port.flags |= UPF_SHARE_IRQ;
2936 ret = serial8250_register_port(&port);
2938 dev_err(&dev->dev, "unable to register port at index %d "
2939 "(IO%lx MEM%llx IRQ%d): %d\n", i,
2940 p->iobase, (unsigned long long)p->mapbase,
2948 * Remove serial ports registered against a platform device.
2950 static int __devexit serial8250_remove(struct platform_device *dev)
2954 for (i = 0; i < nr_uarts; i++) {
2955 struct uart_8250_port *up = &serial8250_ports[i];
2957 if (up->port.dev == &dev->dev)
2958 serial8250_unregister_port(i);
2963 static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
2967 for (i = 0; i < UART_NR; i++) {
2968 struct uart_8250_port *up = &serial8250_ports[i];
2970 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
2971 uart_suspend_port(&serial8250_reg, &up->port);
2977 static int serial8250_resume(struct platform_device *dev)
2981 for (i = 0; i < UART_NR; i++) {
2982 struct uart_8250_port *up = &serial8250_ports[i];
2984 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
2985 serial8250_resume_port(i);
2991 static struct platform_driver serial8250_isa_driver = {
2992 .probe = serial8250_probe,
2993 .remove = __devexit_p(serial8250_remove),
2994 .suspend = serial8250_suspend,
2995 .resume = serial8250_resume,
2997 .name = "serial8250",
2998 .owner = THIS_MODULE,
3003 * This "device" covers _all_ ISA 8250-compatible serial devices listed
3004 * in the table in include/asm/serial.h
3006 static struct platform_device *serial8250_isa_devs;
3009 * serial8250_register_port and serial8250_unregister_port allows for
3010 * 16x50 serial ports to be configured at run-time, to support PCMCIA
3011 * modems and PCI multiport cards.
3013 static DEFINE_MUTEX(serial_mutex);
3015 static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *port)
3020 * First, find a port entry which matches.
3022 for (i = 0; i < nr_uarts; i++)
3023 if (uart_match_port(&serial8250_ports[i].port, port))
3024 return &serial8250_ports[i];
3027 * We didn't find a matching entry, so look for the first
3028 * free entry. We look for one which hasn't been previously
3029 * used (indicated by zero iobase).
3031 for (i = 0; i < nr_uarts; i++)
3032 if (serial8250_ports[i].port.type == PORT_UNKNOWN &&
3033 serial8250_ports[i].port.iobase == 0)
3034 return &serial8250_ports[i];
3037 * That also failed. Last resort is to find any entry which
3038 * doesn't have a real port associated with it.
3040 for (i = 0; i < nr_uarts; i++)
3041 if (serial8250_ports[i].port.type == PORT_UNKNOWN)
3042 return &serial8250_ports[i];
3048 * serial8250_register_port - register a serial port
3049 * @port: serial port template
3051 * Configure the serial port specified by the request. If the
3052 * port exists and is in use, it is hung up and unregistered
3055 * The port is then probed and if necessary the IRQ is autodetected
3056 * If this fails an error is returned.
3058 * On success the port is ready to use and the line number is returned.
3060 int serial8250_register_port(struct uart_port *port)
3062 struct uart_8250_port *uart;
3065 if (port->uartclk == 0)
3068 mutex_lock(&serial_mutex);
3070 uart = serial8250_find_match_or_unused(port);
3072 uart_remove_one_port(&serial8250_reg, &uart->port);
3074 uart->port.iobase = port->iobase;
3075 uart->port.membase = port->membase;
3076 uart->port.irq = port->irq;
3077 uart->port.uartclk = port->uartclk;
3078 uart->port.fifosize = port->fifosize;
3079 uart->port.regshift = port->regshift;
3080 uart->port.iotype = port->iotype;
3081 uart->port.flags = port->flags | UPF_BOOT_AUTOCONF;
3082 uart->port.mapbase = port->mapbase;
3083 uart->port.private_data = port->private_data;
3085 uart->port.dev = port->dev;
3087 if (port->flags & UPF_FIXED_TYPE) {
3088 uart->port.type = port->type;
3089 uart->port.fifosize = uart_config[port->type].fifo_size;
3090 uart->capabilities = uart_config[port->type].flags;
3091 uart->tx_loadsz = uart_config[port->type].tx_loadsz;
3094 set_io_from_upio(&uart->port);
3095 /* Possibly override default I/O functions. */
3096 if (port->serial_in)
3097 uart->port.serial_in = port->serial_in;
3098 if (port->serial_out)
3099 uart->port.serial_out = port->serial_out;
3101 ret = uart_add_one_port(&serial8250_reg, &uart->port);
3103 ret = uart->port.line;
3105 mutex_unlock(&serial_mutex);
3109 EXPORT_SYMBOL(serial8250_register_port);
3112 * serial8250_unregister_port - remove a 16x50 serial port at runtime
3113 * @line: serial line number
3115 * Remove one serial port. This may not be called from interrupt
3116 * context. We hand the port back to the our control.
3118 void serial8250_unregister_port(int line)
3120 struct uart_8250_port *uart = &serial8250_ports[line];
3122 mutex_lock(&serial_mutex);
3123 uart_remove_one_port(&serial8250_reg, &uart->port);
3124 if (serial8250_isa_devs) {
3125 uart->port.flags &= ~UPF_BOOT_AUTOCONF;
3126 uart->port.type = PORT_UNKNOWN;
3127 uart->port.dev = &serial8250_isa_devs->dev;
3128 uart_add_one_port(&serial8250_reg, &uart->port);
3130 uart->port.dev = NULL;
3132 mutex_unlock(&serial_mutex);
3134 EXPORT_SYMBOL(serial8250_unregister_port);
3136 static int __init serial8250_init(void)
3140 if (nr_uarts > UART_NR)
3143 printk(KERN_INFO "Serial: 8250/16550 driver, "
3144 "%d ports, IRQ sharing %sabled\n", nr_uarts,
3145 share_irqs ? "en" : "dis");
3148 ret = sunserial_register_minors(&serial8250_reg, UART_NR);
3150 serial8250_reg.nr = UART_NR;
3151 ret = uart_register_driver(&serial8250_reg);
3156 serial8250_isa_devs = platform_device_alloc("serial8250",
3157 PLAT8250_DEV_LEGACY);
3158 if (!serial8250_isa_devs) {
3160 goto unreg_uart_drv;
3163 ret = platform_device_add(serial8250_isa_devs);
3167 serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);
3169 ret = platform_driver_register(&serial8250_isa_driver);
3173 platform_device_del(serial8250_isa_devs);
3175 platform_device_put(serial8250_isa_devs);
3178 sunserial_unregister_minors(&serial8250_reg, UART_NR);
3180 uart_unregister_driver(&serial8250_reg);
3186 static void __exit serial8250_exit(void)
3188 struct platform_device *isa_dev = serial8250_isa_devs;
3191 * This tells serial8250_unregister_port() not to re-register
3192 * the ports (thereby making serial8250_isa_driver permanently
3195 serial8250_isa_devs = NULL;
3197 platform_driver_unregister(&serial8250_isa_driver);
3198 platform_device_unregister(isa_dev);
3201 sunserial_unregister_minors(&serial8250_reg, UART_NR);
3203 uart_unregister_driver(&serial8250_reg);
3207 module_init(serial8250_init);
3208 module_exit(serial8250_exit);
3210 EXPORT_SYMBOL(serial8250_suspend_port);
3211 EXPORT_SYMBOL(serial8250_resume_port);
3213 MODULE_LICENSE("GPL");
3214 MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
3216 module_param(share_irqs, uint, 0644);
3217 MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"
3220 module_param(nr_uarts, uint, 0644);
3221 MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");
3223 #ifdef CONFIG_SERIAL_8250_RSA
3224 module_param_array(probe_rsa, ulong, &probe_rsa_count, 0444);
3225 MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
3227 MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);