2 * Driver for 8250/16550-type serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Copyright (C) 2001 Russell King.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * A note about mapbase / membase
15 * mapbase is the physical address of the IO port.
16 * membase is an 'ioremapped' cookie.
19 #if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/ioport.h>
26 #include <linux/init.h>
27 #include <linux/console.h>
28 #include <linux/sysrq.h>
29 #include <linux/delay.h>
30 #include <linux/platform_device.h>
31 #include <linux/tty.h>
32 #include <linux/ratelimit.h>
33 #include <linux/tty_flip.h>
34 #include <linux/serial_core.h>
35 #include <linux/serial.h>
36 #include <linux/serial_8250.h>
37 #include <linux/nmi.h>
38 #include <linux/mutex.h>
39 #include <linux/slab.h>
40 #include <linux/uaccess.h>
41 #include <linux/pm_runtime.h>
43 #include <linux/sunserialcore.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;
67 static unsigned int skip_txen_test; /* force skip of txen test at init time */
73 #define DEBUG_AUTOCONF(fmt...) printk(fmt)
75 #define DEBUG_AUTOCONF(fmt...) do { } while (0)
79 #define DEBUG_INTR(fmt...) printk(fmt)
81 #define DEBUG_INTR(fmt...) do { } while (0)
84 #define PASS_LIMIT 512
86 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
89 #ifdef CONFIG_SERIAL_8250_DETECT_IRQ
90 #define CONFIG_SERIAL_DETECT_IRQ 1
92 #ifdef CONFIG_SERIAL_8250_MANY_PORTS
93 #define CONFIG_SERIAL_MANY_PORTS 1
97 * HUB6 is always on. This will be removed once the header
98 * files have been cleaned.
100 #define CONFIG_HUB6 1
102 #include <asm/serial.h>
104 * SERIAL_PORT_DFNS tells us about built-in ports that have no
105 * standard enumeration mechanism. Platforms that can find all
106 * serial ports via mechanisms like ACPI or PCI need not supply it.
108 #ifndef SERIAL_PORT_DFNS
109 #define SERIAL_PORT_DFNS
112 static const struct old_serial_port old_serial_port[] = {
113 SERIAL_PORT_DFNS /* defined in asm/serial.h */
116 #define UART_NR CONFIG_SERIAL_8250_NR_UARTS
118 #ifdef CONFIG_SERIAL_8250_RSA
120 #define PORT_RSA_MAX 4
121 static unsigned long probe_rsa[PORT_RSA_MAX];
122 static unsigned int probe_rsa_count;
123 #endif /* CONFIG_SERIAL_8250_RSA */
126 struct hlist_node node;
128 spinlock_t lock; /* Protects list not the hash */
129 struct list_head *head;
132 #define NR_IRQ_HASH 32 /* Can be adjusted later */
133 static struct hlist_head irq_lists[NR_IRQ_HASH];
134 static DEFINE_MUTEX(hash_mutex); /* Used to walk the hash */
137 * Here we define the default xmit fifo size used for each type of UART.
139 static const struct serial8250_config uart_config[] = {
164 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
165 .rxtrig_bytes = {1, 4, 8, 14},
166 .flags = UART_CAP_FIFO,
177 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
183 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
185 .rxtrig_bytes = {8, 16, 24, 28},
186 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
192 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
194 .rxtrig_bytes = {1, 16, 32, 56},
195 .flags = UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE,
203 .name = "16C950/954",
206 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
207 /* UART_CAP_EFR breaks billionon CF bluetooth card. */
208 .flags = UART_CAP_FIFO | UART_CAP_SLEEP,
214 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
216 .rxtrig_bytes = {8, 16, 56, 60},
217 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
223 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
224 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
230 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11,
231 .flags = UART_CAP_FIFO,
237 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
238 .flags = UART_CAP_FIFO | UART_NATSEMI,
244 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
245 .flags = UART_CAP_FIFO | UART_CAP_UUE | UART_CAP_RTOIE,
251 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
252 .flags = UART_CAP_FIFO,
258 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
259 .flags = UART_CAP_FIFO | UART_CAP_AFE,
265 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
266 .flags = UART_CAP_FIFO | UART_CAP_AFE,
272 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
274 .rxtrig_bytes = {1, 4, 8, 14},
275 .flags = UART_CAP_FIFO | UART_CAP_RTOIE,
281 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
282 .flags = UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR |
289 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11 |
291 .flags = UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR |
298 .fcr = UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO |
299 UART_FCR_R_TRIG_00 | UART_FCR_T_TRIG_00,
300 .flags = UART_CAP_FIFO,
302 [PORT_BRCM_TRUMANAGE] = {
306 .flags = UART_CAP_HFIFO,
311 [PORT_ALTR_16550_F32] = {
312 .name = "Altera 16550 FIFO32",
315 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
316 .flags = UART_CAP_FIFO | UART_CAP_AFE,
318 [PORT_ALTR_16550_F64] = {
319 .name = "Altera 16550 FIFO64",
322 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
323 .flags = UART_CAP_FIFO | UART_CAP_AFE,
325 [PORT_ALTR_16550_F128] = {
326 .name = "Altera 16550 FIFO128",
329 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
330 .flags = UART_CAP_FIFO | UART_CAP_AFE,
332 /* tx_loadsz is set to 63-bytes instead of 64-bytes to implement
333 workaround of errata A-008006 which states that tx_loadsz should be
334 configured less than Maximum supported fifo bytes */
335 [PORT_16550A_FSL64] = {
336 .name = "16550A_FSL64",
339 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
341 .flags = UART_CAP_FIFO,
345 /* Uart divisor latch read */
346 static int default_serial_dl_read(struct uart_8250_port *up)
348 return serial_in(up, UART_DLL) | serial_in(up, UART_DLM) << 8;
351 /* Uart divisor latch write */
352 static void default_serial_dl_write(struct uart_8250_port *up, int value)
354 serial_out(up, UART_DLL, value & 0xff);
355 serial_out(up, UART_DLM, value >> 8 & 0xff);
358 #if defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_SERIAL_8250_RT288X)
360 /* Au1x00/RT288x UART hardware has a weird register layout */
361 static const u8 au_io_in_map[] = {
371 static const u8 au_io_out_map[] = {
379 static unsigned int au_serial_in(struct uart_port *p, int offset)
381 offset = au_io_in_map[offset] << p->regshift;
382 return __raw_readl(p->membase + offset);
385 static void au_serial_out(struct uart_port *p, int offset, int value)
387 offset = au_io_out_map[offset] << p->regshift;
388 __raw_writel(value, p->membase + offset);
391 /* Au1x00 haven't got a standard divisor latch */
392 static int au_serial_dl_read(struct uart_8250_port *up)
394 return __raw_readl(up->port.membase + 0x28);
397 static void au_serial_dl_write(struct uart_8250_port *up, int value)
399 __raw_writel(value, up->port.membase + 0x28);
404 static unsigned int hub6_serial_in(struct uart_port *p, int offset)
406 offset = offset << p->regshift;
407 outb(p->hub6 - 1 + offset, p->iobase);
408 return inb(p->iobase + 1);
411 static void hub6_serial_out(struct uart_port *p, int offset, int value)
413 offset = offset << p->regshift;
414 outb(p->hub6 - 1 + offset, p->iobase);
415 outb(value, p->iobase + 1);
418 static unsigned int mem_serial_in(struct uart_port *p, int offset)
420 offset = offset << p->regshift;
421 return readb(p->membase + offset);
424 static void mem_serial_out(struct uart_port *p, int offset, int value)
426 offset = offset << p->regshift;
427 writeb(value, p->membase + offset);
430 static void mem32_serial_out(struct uart_port *p, int offset, int value)
432 offset = offset << p->regshift;
433 writel(value, p->membase + offset);
436 static unsigned int mem32_serial_in(struct uart_port *p, int offset)
438 offset = offset << p->regshift;
439 return readl(p->membase + offset);
442 static unsigned int io_serial_in(struct uart_port *p, int offset)
444 offset = offset << p->regshift;
445 return inb(p->iobase + offset);
448 static void io_serial_out(struct uart_port *p, int offset, int value)
450 offset = offset << p->regshift;
451 outb(value, p->iobase + offset);
454 static int serial8250_default_handle_irq(struct uart_port *port);
455 static int exar_handle_irq(struct uart_port *port);
457 static void set_io_from_upio(struct uart_port *p)
459 struct uart_8250_port *up = up_to_u8250p(p);
461 up->dl_read = default_serial_dl_read;
462 up->dl_write = default_serial_dl_write;
466 p->serial_in = hub6_serial_in;
467 p->serial_out = hub6_serial_out;
471 p->serial_in = mem_serial_in;
472 p->serial_out = mem_serial_out;
476 p->serial_in = mem32_serial_in;
477 p->serial_out = mem32_serial_out;
480 #if defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_SERIAL_8250_RT288X)
482 p->serial_in = au_serial_in;
483 p->serial_out = au_serial_out;
484 up->dl_read = au_serial_dl_read;
485 up->dl_write = au_serial_dl_write;
490 p->serial_in = io_serial_in;
491 p->serial_out = io_serial_out;
494 /* Remember loaded iotype */
495 up->cur_iotype = p->iotype;
496 p->handle_irq = serial8250_default_handle_irq;
500 serial_port_out_sync(struct uart_port *p, int offset, int value)
506 p->serial_out(p, offset, value);
507 p->serial_in(p, UART_LCR); /* safe, no side-effects */
510 p->serial_out(p, offset, value);
517 static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
519 serial_out(up, UART_SCR, offset);
520 serial_out(up, UART_ICR, value);
523 static unsigned int serial_icr_read(struct uart_8250_port *up, int offset)
527 serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
528 serial_out(up, UART_SCR, offset);
529 value = serial_in(up, UART_ICR);
530 serial_icr_write(up, UART_ACR, up->acr);
538 static void serial8250_clear_fifos(struct uart_8250_port *p)
540 if (p->capabilities & UART_CAP_FIFO) {
541 serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO);
542 serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO |
543 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
544 serial_out(p, UART_FCR, 0);
548 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p)
550 serial8250_clear_fifos(p);
551 serial_out(p, UART_FCR, p->fcr);
553 EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos);
555 void serial8250_rpm_get(struct uart_8250_port *p)
557 if (!(p->capabilities & UART_CAP_RPM))
559 pm_runtime_get_sync(p->port.dev);
561 EXPORT_SYMBOL_GPL(serial8250_rpm_get);
563 void serial8250_rpm_put(struct uart_8250_port *p)
565 if (!(p->capabilities & UART_CAP_RPM))
567 pm_runtime_mark_last_busy(p->port.dev);
568 pm_runtime_put_autosuspend(p->port.dev);
570 EXPORT_SYMBOL_GPL(serial8250_rpm_put);
573 * These two wrappers ensure that enable_runtime_pm_tx() can be called more than
574 * once and disable_runtime_pm_tx() will still disable RPM because the fifo is
575 * empty and the HW can idle again.
577 static void serial8250_rpm_get_tx(struct uart_8250_port *p)
579 unsigned char rpm_active;
581 if (!(p->capabilities & UART_CAP_RPM))
584 rpm_active = xchg(&p->rpm_tx_active, 1);
587 pm_runtime_get_sync(p->port.dev);
590 static void serial8250_rpm_put_tx(struct uart_8250_port *p)
592 unsigned char rpm_active;
594 if (!(p->capabilities & UART_CAP_RPM))
597 rpm_active = xchg(&p->rpm_tx_active, 0);
600 pm_runtime_mark_last_busy(p->port.dev);
601 pm_runtime_put_autosuspend(p->port.dev);
605 * IER sleep support. UARTs which have EFRs need the "extended
606 * capability" bit enabled. Note that on XR16C850s, we need to
607 * reset LCR to write to IER.
609 static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
611 unsigned char lcr = 0, efr = 0;
613 * Exar UARTs have a SLEEP register that enables or disables
614 * each UART to enter sleep mode separately. On the XR17V35x the
615 * register is accessible to each UART at the UART_EXAR_SLEEP
616 * offset but the UART channel may only write to the corresponding
619 serial8250_rpm_get(p);
620 if ((p->port.type == PORT_XR17V35X) ||
621 (p->port.type == PORT_XR17D15X)) {
622 serial_out(p, UART_EXAR_SLEEP, sleep ? 0xff : 0);
626 if (p->capabilities & UART_CAP_SLEEP) {
627 if (p->capabilities & UART_CAP_EFR) {
628 lcr = serial_in(p, UART_LCR);
629 efr = serial_in(p, UART_EFR);
630 serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B);
631 serial_out(p, UART_EFR, UART_EFR_ECB);
632 serial_out(p, UART_LCR, 0);
634 serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
635 if (p->capabilities & UART_CAP_EFR) {
636 serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B);
637 serial_out(p, UART_EFR, efr);
638 serial_out(p, UART_LCR, lcr);
642 serial8250_rpm_put(p);
645 #ifdef CONFIG_SERIAL_8250_RSA
647 * Attempts to turn on the RSA FIFO. Returns zero on failure.
648 * We set the port uart clock rate if we succeed.
650 static int __enable_rsa(struct uart_8250_port *up)
655 mode = serial_in(up, UART_RSA_MSR);
656 result = mode & UART_RSA_MSR_FIFO;
659 serial_out(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
660 mode = serial_in(up, UART_RSA_MSR);
661 result = mode & UART_RSA_MSR_FIFO;
665 up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
670 static void enable_rsa(struct uart_8250_port *up)
672 if (up->port.type == PORT_RSA) {
673 if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
674 spin_lock_irq(&up->port.lock);
676 spin_unlock_irq(&up->port.lock);
678 if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
679 serial_out(up, UART_RSA_FRR, 0);
684 * Attempts to turn off the RSA FIFO. Returns zero on failure.
685 * It is unknown why interrupts were disabled in here. However,
686 * the caller is expected to preserve this behaviour by grabbing
687 * the spinlock before calling this function.
689 static void disable_rsa(struct uart_8250_port *up)
694 if (up->port.type == PORT_RSA &&
695 up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
696 spin_lock_irq(&up->port.lock);
698 mode = serial_in(up, UART_RSA_MSR);
699 result = !(mode & UART_RSA_MSR_FIFO);
702 serial_out(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
703 mode = serial_in(up, UART_RSA_MSR);
704 result = !(mode & UART_RSA_MSR_FIFO);
708 up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
709 spin_unlock_irq(&up->port.lock);
712 #endif /* CONFIG_SERIAL_8250_RSA */
715 * This is a quickie test to see how big the FIFO is.
716 * It doesn't work at all the time, more's the pity.
718 static int size_fifo(struct uart_8250_port *up)
720 unsigned char old_fcr, old_mcr, old_lcr;
721 unsigned short old_dl;
724 old_lcr = serial_in(up, UART_LCR);
725 serial_out(up, UART_LCR, 0);
726 old_fcr = serial_in(up, UART_FCR);
727 old_mcr = serial_in(up, UART_MCR);
728 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
729 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
730 serial_out(up, UART_MCR, UART_MCR_LOOP);
731 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
732 old_dl = serial_dl_read(up);
733 serial_dl_write(up, 0x0001);
734 serial_out(up, UART_LCR, 0x03);
735 for (count = 0; count < 256; count++)
736 serial_out(up, UART_TX, count);
737 mdelay(20);/* FIXME - schedule_timeout */
738 for (count = 0; (serial_in(up, UART_LSR) & UART_LSR_DR) &&
739 (count < 256); count++)
740 serial_in(up, UART_RX);
741 serial_out(up, UART_FCR, old_fcr);
742 serial_out(up, UART_MCR, old_mcr);
743 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
744 serial_dl_write(up, old_dl);
745 serial_out(up, UART_LCR, old_lcr);
751 * Read UART ID using the divisor method - set DLL and DLM to zero
752 * and the revision will be in DLL and device type in DLM. We
753 * preserve the device state across this.
755 static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
757 unsigned char old_dll, old_dlm, old_lcr;
760 old_lcr = serial_in(p, UART_LCR);
761 serial_out(p, UART_LCR, UART_LCR_CONF_MODE_A);
763 old_dll = serial_in(p, UART_DLL);
764 old_dlm = serial_in(p, UART_DLM);
766 serial_out(p, UART_DLL, 0);
767 serial_out(p, UART_DLM, 0);
769 id = serial_in(p, UART_DLL) | serial_in(p, UART_DLM) << 8;
771 serial_out(p, UART_DLL, old_dll);
772 serial_out(p, UART_DLM, old_dlm);
773 serial_out(p, UART_LCR, old_lcr);
779 * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's.
780 * When this function is called we know it is at least a StarTech
781 * 16650 V2, but it might be one of several StarTech UARTs, or one of
782 * its clones. (We treat the broken original StarTech 16650 V1 as a
783 * 16550, and why not? Startech doesn't seem to even acknowledge its
786 * What evil have men's minds wrought...
788 static void autoconfig_has_efr(struct uart_8250_port *up)
790 unsigned int id1, id2, id3, rev;
793 * Everything with an EFR has SLEEP
795 up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
798 * First we check to see if it's an Oxford Semiconductor UART.
800 * If we have to do this here because some non-National
801 * Semiconductor clone chips lock up if you try writing to the
802 * LSR register (which serial_icr_read does)
806 * Check for Oxford Semiconductor 16C950.
808 * EFR [4] must be set else this test fails.
810 * This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca)
811 * claims that it's needed for 952 dual UART's (which are not
812 * recommended for new designs).
815 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
816 serial_out(up, UART_EFR, UART_EFR_ECB);
817 serial_out(up, UART_LCR, 0x00);
818 id1 = serial_icr_read(up, UART_ID1);
819 id2 = serial_icr_read(up, UART_ID2);
820 id3 = serial_icr_read(up, UART_ID3);
821 rev = serial_icr_read(up, UART_REV);
823 DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);
825 if (id1 == 0x16 && id2 == 0xC9 &&
826 (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
827 up->port.type = PORT_16C950;
830 * Enable work around for the Oxford Semiconductor 952 rev B
831 * chip which causes it to seriously miscalculate baud rates
834 if (id3 == 0x52 && rev == 0x01)
835 up->bugs |= UART_BUG_QUOT;
840 * We check for a XR16C850 by setting DLL and DLM to 0, and then
841 * reading back DLL and DLM. The chip type depends on the DLM
843 * 0x10 - XR16C850 and the DLL contains the chip revision.
847 id1 = autoconfig_read_divisor_id(up);
848 DEBUG_AUTOCONF("850id=%04x ", id1);
851 if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
852 up->port.type = PORT_16850;
857 * It wasn't an XR16C850.
859 * We distinguish between the '654 and the '650 by counting
860 * how many bytes are in the FIFO. I'm using this for now,
861 * since that's the technique that was sent to me in the
862 * serial driver update, but I'm not convinced this works.
863 * I've had problems doing this in the past. -TYT
865 if (size_fifo(up) == 64)
866 up->port.type = PORT_16654;
868 up->port.type = PORT_16650V2;
872 * We detected a chip without a FIFO. Only two fall into
873 * this category - the original 8250 and the 16450. The
874 * 16450 has a scratch register (accessible with LCR=0)
876 static void autoconfig_8250(struct uart_8250_port *up)
878 unsigned char scratch, status1, status2;
880 up->port.type = PORT_8250;
882 scratch = serial_in(up, UART_SCR);
883 serial_out(up, UART_SCR, 0xa5);
884 status1 = serial_in(up, UART_SCR);
885 serial_out(up, UART_SCR, 0x5a);
886 status2 = serial_in(up, UART_SCR);
887 serial_out(up, UART_SCR, scratch);
889 if (status1 == 0xa5 && status2 == 0x5a)
890 up->port.type = PORT_16450;
893 static int broken_efr(struct uart_8250_port *up)
896 * Exar ST16C2550 "A2" devices incorrectly detect as
897 * having an EFR, and report an ID of 0x0201. See
898 * http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-11/4812.html
900 if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
906 static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
908 unsigned char status;
910 status = serial_in(up, 0x04); /* EXCR2 */
911 #define PRESL(x) ((x) & 0x30)
912 if (PRESL(status) == 0x10) {
913 /* already in high speed mode */
916 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
917 status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
918 serial_out(up, 0x04, status);
924 * We know that the chip has FIFOs. Does it have an EFR? The
925 * EFR is located in the same register position as the IIR and
926 * we know the top two bits of the IIR are currently set. The
927 * EFR should contain zero. Try to read the EFR.
929 static void autoconfig_16550a(struct uart_8250_port *up)
931 unsigned char status1, status2;
932 unsigned int iersave;
934 up->port.type = PORT_16550A;
935 up->capabilities |= UART_CAP_FIFO;
938 * XR17V35x UARTs have an extra divisor register, DLD
939 * that gets enabled with when DLAB is set which will
940 * cause the device to incorrectly match and assign
941 * port type to PORT_16650. The EFR for this UART is
942 * found at offset 0x09. Instead check the Deice ID (DVID)
943 * register for a 2, 4 or 8 port UART.
945 if (up->port.flags & UPF_EXAR_EFR) {
946 status1 = serial_in(up, UART_EXAR_DVID);
947 if (status1 == 0x82 || status1 == 0x84 || status1 == 0x88) {
948 DEBUG_AUTOCONF("Exar XR17V35x ");
949 up->port.type = PORT_XR17V35X;
950 up->capabilities |= UART_CAP_AFE | UART_CAP_EFR |
959 * Check for presence of the EFR when DLAB is set.
960 * Only ST16C650V1 UARTs pass this test.
962 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
963 if (serial_in(up, UART_EFR) == 0) {
964 serial_out(up, UART_EFR, 0xA8);
965 if (serial_in(up, UART_EFR) != 0) {
966 DEBUG_AUTOCONF("EFRv1 ");
967 up->port.type = PORT_16650;
968 up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
970 serial_out(up, UART_LCR, 0);
971 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
973 status1 = serial_in(up, UART_IIR) >> 5;
974 serial_out(up, UART_FCR, 0);
975 serial_out(up, UART_LCR, 0);
978 up->port.type = PORT_16550A_FSL64;
980 DEBUG_AUTOCONF("Motorola 8xxx DUART ");
982 serial_out(up, UART_EFR, 0);
987 * Maybe it requires 0xbf to be written to the LCR.
988 * (other ST16C650V2 UARTs, TI16C752A, etc)
990 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
991 if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
992 DEBUG_AUTOCONF("EFRv2 ");
993 autoconfig_has_efr(up);
998 * Check for a National Semiconductor SuperIO chip.
999 * Attempt to switch to bank 2, read the value of the LOOP bit
1000 * from EXCR1. Switch back to bank 0, change it in MCR. Then
1001 * switch back to bank 2, read it from EXCR1 again and check
1002 * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2
1004 serial_out(up, UART_LCR, 0);
1005 status1 = serial_in(up, UART_MCR);
1006 serial_out(up, UART_LCR, 0xE0);
1007 status2 = serial_in(up, 0x02); /* EXCR1 */
1009 if (!((status2 ^ status1) & UART_MCR_LOOP)) {
1010 serial_out(up, UART_LCR, 0);
1011 serial_out(up, UART_MCR, status1 ^ UART_MCR_LOOP);
1012 serial_out(up, UART_LCR, 0xE0);
1013 status2 = serial_in(up, 0x02); /* EXCR1 */
1014 serial_out(up, UART_LCR, 0);
1015 serial_out(up, UART_MCR, status1);
1017 if ((status2 ^ status1) & UART_MCR_LOOP) {
1018 unsigned short quot;
1020 serial_out(up, UART_LCR, 0xE0);
1022 quot = serial_dl_read(up);
1025 if (ns16550a_goto_highspeed(up))
1026 serial_dl_write(up, quot);
1028 serial_out(up, UART_LCR, 0);
1030 up->port.uartclk = 921600*16;
1031 up->port.type = PORT_NS16550A;
1032 up->capabilities |= UART_NATSEMI;
1038 * No EFR. Try to detect a TI16750, which only sets bit 5 of
1039 * the IIR when 64 byte FIFO mode is enabled when DLAB is set.
1040 * Try setting it with and without DLAB set. Cheap clones
1041 * set bit 5 without DLAB set.
1043 serial_out(up, UART_LCR, 0);
1044 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
1045 status1 = serial_in(up, UART_IIR) >> 5;
1046 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1047 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
1048 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
1049 status2 = serial_in(up, UART_IIR) >> 5;
1050 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1051 serial_out(up, UART_LCR, 0);
1053 DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
1055 if (status1 == 6 && status2 == 7) {
1056 up->port.type = PORT_16750;
1057 up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
1062 * Try writing and reading the UART_IER_UUE bit (b6).
1063 * If it works, this is probably one of the Xscale platform's
1065 * We're going to explicitly set the UUE bit to 0 before
1066 * trying to write and read a 1 just to make sure it's not
1067 * already a 1 and maybe locked there before we even start start.
1069 iersave = serial_in(up, UART_IER);
1070 serial_out(up, UART_IER, iersave & ~UART_IER_UUE);
1071 if (!(serial_in(up, UART_IER) & UART_IER_UUE)) {
1073 * OK it's in a known zero state, try writing and reading
1074 * without disturbing the current state of the other bits.
1076 serial_out(up, UART_IER, iersave | UART_IER_UUE);
1077 if (serial_in(up, UART_IER) & UART_IER_UUE) {
1080 * We'll leave the UART_IER_UUE bit set to 1 (enabled).
1082 DEBUG_AUTOCONF("Xscale ");
1083 up->port.type = PORT_XSCALE;
1084 up->capabilities |= UART_CAP_UUE | UART_CAP_RTOIE;
1089 * If we got here we couldn't force the IER_UUE bit to 0.
1090 * Log it and continue.
1092 DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
1094 serial_out(up, UART_IER, iersave);
1097 * Exar uarts have EFR in a weird location
1099 if (up->port.flags & UPF_EXAR_EFR) {
1100 DEBUG_AUTOCONF("Exar XR17D15x ");
1101 up->port.type = PORT_XR17D15X;
1102 up->capabilities |= UART_CAP_AFE | UART_CAP_EFR |
1109 * We distinguish between 16550A and U6 16550A by counting
1110 * how many bytes are in the FIFO.
1112 if (up->port.type == PORT_16550A && size_fifo(up) == 64) {
1113 up->port.type = PORT_U6_16550A;
1114 up->capabilities |= UART_CAP_AFE;
1119 * This routine is called by rs_init() to initialize a specific serial
1120 * port. It determines what type of UART chip this serial port is
1121 * using: 8250, 16450, 16550, 16550A. The important question is
1122 * whether or not this UART is a 16550A or not, since this will
1123 * determine whether or not we can use its FIFO features or not.
1125 static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
1127 unsigned char status1, scratch, scratch2, scratch3;
1128 unsigned char save_lcr, save_mcr;
1129 struct uart_port *port = &up->port;
1130 unsigned long flags;
1131 unsigned int old_capabilities;
1133 if (!port->iobase && !port->mapbase && !port->membase)
1136 DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04lx, 0x%p): ",
1137 serial_index(port), port->iobase, port->membase);
1140 * We really do need global IRQs disabled here - we're going to
1141 * be frobbing the chips IRQ enable register to see if it exists.
1143 spin_lock_irqsave(&port->lock, flags);
1145 up->capabilities = 0;
1148 if (!(port->flags & UPF_BUGGY_UART)) {
1150 * Do a simple existence test first; if we fail this,
1151 * there's no point trying anything else.
1153 * 0x80 is used as a nonsense port to prevent against
1154 * false positives due to ISA bus float. The
1155 * assumption is that 0x80 is a non-existent port;
1156 * which should be safe since include/asm/io.h also
1157 * makes this assumption.
1159 * Note: this is safe as long as MCR bit 4 is clear
1160 * and the device is in "PC" mode.
1162 scratch = serial_in(up, UART_IER);
1163 serial_out(up, UART_IER, 0);
1168 * Mask out IER[7:4] bits for test as some UARTs (e.g. TL
1169 * 16C754B) allow only to modify them if an EFR bit is set.
1171 scratch2 = serial_in(up, UART_IER) & 0x0f;
1172 serial_out(up, UART_IER, 0x0F);
1176 scratch3 = serial_in(up, UART_IER) & 0x0f;
1177 serial_out(up, UART_IER, scratch);
1178 if (scratch2 != 0 || scratch3 != 0x0F) {
1180 * We failed; there's nothing here
1182 spin_unlock_irqrestore(&port->lock, flags);
1183 DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
1184 scratch2, scratch3);
1189 save_mcr = serial_in(up, UART_MCR);
1190 save_lcr = serial_in(up, UART_LCR);
1193 * Check to see if a UART is really there. Certain broken
1194 * internal modems based on the Rockwell chipset fail this
1195 * test, because they apparently don't implement the loopback
1196 * test mode. So this test is skipped on the COM 1 through
1197 * COM 4 ports. This *should* be safe, since no board
1198 * manufacturer would be stupid enough to design a board
1199 * that conflicts with COM 1-4 --- we hope!
1201 if (!(port->flags & UPF_SKIP_TEST)) {
1202 serial_out(up, UART_MCR, UART_MCR_LOOP | 0x0A);
1203 status1 = serial_in(up, UART_MSR) & 0xF0;
1204 serial_out(up, UART_MCR, save_mcr);
1205 if (status1 != 0x90) {
1206 spin_unlock_irqrestore(&port->lock, flags);
1207 DEBUG_AUTOCONF("LOOP test failed (%02x) ",
1214 * We're pretty sure there's a port here. Lets find out what
1215 * type of port it is. The IIR top two bits allows us to find
1216 * out if it's 8250 or 16450, 16550, 16550A or later. This
1217 * determines what we test for next.
1219 * We also initialise the EFR (if any) to zero for later. The
1220 * EFR occupies the same register location as the FCR and IIR.
1222 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1223 serial_out(up, UART_EFR, 0);
1224 serial_out(up, UART_LCR, 0);
1226 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1227 scratch = serial_in(up, UART_IIR) >> 6;
1231 autoconfig_8250(up);
1234 port->type = PORT_UNKNOWN;
1237 port->type = PORT_16550;
1240 autoconfig_16550a(up);
1244 #ifdef CONFIG_SERIAL_8250_RSA
1246 * Only probe for RSA ports if we got the region.
1248 if (port->type == PORT_16550A && probeflags & PROBE_RSA) {
1251 for (i = 0 ; i < probe_rsa_count; ++i) {
1252 if (probe_rsa[i] == port->iobase && __enable_rsa(up)) {
1253 port->type = PORT_RSA;
1260 serial_out(up, UART_LCR, save_lcr);
1262 port->fifosize = uart_config[up->port.type].fifo_size;
1263 old_capabilities = up->capabilities;
1264 up->capabilities = uart_config[port->type].flags;
1265 up->tx_loadsz = uart_config[port->type].tx_loadsz;
1267 if (port->type == PORT_UNKNOWN)
1273 #ifdef CONFIG_SERIAL_8250_RSA
1274 if (port->type == PORT_RSA)
1275 serial_out(up, UART_RSA_FRR, 0);
1277 serial_out(up, UART_MCR, save_mcr);
1278 serial8250_clear_fifos(up);
1279 serial_in(up, UART_RX);
1280 if (up->capabilities & UART_CAP_UUE)
1281 serial_out(up, UART_IER, UART_IER_UUE);
1283 serial_out(up, UART_IER, 0);
1286 spin_unlock_irqrestore(&port->lock, flags);
1287 if (up->capabilities != old_capabilities) {
1289 "ttyS%d: detected caps %08x should be %08x\n",
1290 serial_index(port), old_capabilities,
1294 DEBUG_AUTOCONF("iir=%d ", scratch);
1295 DEBUG_AUTOCONF("type=%s\n", uart_config[port->type].name);
1298 static void autoconfig_irq(struct uart_8250_port *up)
1300 struct uart_port *port = &up->port;
1301 unsigned char save_mcr, save_ier;
1302 unsigned char save_ICP = 0;
1303 unsigned int ICP = 0;
1307 if (port->flags & UPF_FOURPORT) {
1308 ICP = (port->iobase & 0xfe0) | 0x1f;
1309 save_ICP = inb_p(ICP);
1314 /* forget possible initially masked and pending IRQ */
1315 probe_irq_off(probe_irq_on());
1316 save_mcr = serial_in(up, UART_MCR);
1317 save_ier = serial_in(up, UART_IER);
1318 serial_out(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2);
1320 irqs = probe_irq_on();
1321 serial_out(up, UART_MCR, 0);
1323 if (port->flags & UPF_FOURPORT) {
1324 serial_out(up, UART_MCR,
1325 UART_MCR_DTR | UART_MCR_RTS);
1327 serial_out(up, UART_MCR,
1328 UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
1330 serial_out(up, UART_IER, 0x0f); /* enable all intrs */
1331 serial_in(up, UART_LSR);
1332 serial_in(up, UART_RX);
1333 serial_in(up, UART_IIR);
1334 serial_in(up, UART_MSR);
1335 serial_out(up, UART_TX, 0xFF);
1337 irq = probe_irq_off(irqs);
1339 serial_out(up, UART_MCR, save_mcr);
1340 serial_out(up, UART_IER, save_ier);
1342 if (port->flags & UPF_FOURPORT)
1343 outb_p(save_ICP, ICP);
1345 port->irq = (irq > 0) ? irq : 0;
1348 static inline void __stop_tx(struct uart_8250_port *p)
1350 if (p->ier & UART_IER_THRI) {
1351 p->ier &= ~UART_IER_THRI;
1352 serial_out(p, UART_IER, p->ier);
1353 serial8250_rpm_put_tx(p);
1357 static void serial8250_stop_tx(struct uart_port *port)
1359 struct uart_8250_port *up = up_to_u8250p(port);
1361 serial8250_rpm_get(up);
1365 * We really want to stop the transmitter from sending.
1367 if (port->type == PORT_16C950) {
1368 up->acr |= UART_ACR_TXDIS;
1369 serial_icr_write(up, UART_ACR, up->acr);
1371 serial8250_rpm_put(up);
1374 static void serial8250_start_tx(struct uart_port *port)
1376 struct uart_8250_port *up = up_to_u8250p(port);
1378 serial8250_rpm_get_tx(up);
1380 if (up->dma && !up->dma->tx_dma(up))
1383 if (!(up->ier & UART_IER_THRI)) {
1384 up->ier |= UART_IER_THRI;
1385 serial_port_out(port, UART_IER, up->ier);
1387 if (up->bugs & UART_BUG_TXEN) {
1389 lsr = serial_in(up, UART_LSR);
1390 up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
1391 if (lsr & UART_LSR_TEMT)
1392 serial8250_tx_chars(up);
1397 * Re-enable the transmitter if we disabled it.
1399 if (port->type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
1400 up->acr &= ~UART_ACR_TXDIS;
1401 serial_icr_write(up, UART_ACR, up->acr);
1405 static void serial8250_throttle(struct uart_port *port)
1407 port->throttle(port);
1410 static void serial8250_unthrottle(struct uart_port *port)
1412 port->unthrottle(port);
1415 static void serial8250_stop_rx(struct uart_port *port)
1417 struct uart_8250_port *up = up_to_u8250p(port);
1419 serial8250_rpm_get(up);
1421 up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
1422 up->port.read_status_mask &= ~UART_LSR_DR;
1423 serial_port_out(port, UART_IER, up->ier);
1425 serial8250_rpm_put(up);
1428 static void serial8250_disable_ms(struct uart_port *port)
1430 struct uart_8250_port *up =
1431 container_of(port, struct uart_8250_port, port);
1433 /* no MSR capabilities */
1434 if (up->bugs & UART_BUG_NOMSR)
1437 up->ier &= ~UART_IER_MSI;
1438 serial_port_out(port, UART_IER, up->ier);
1441 static void serial8250_enable_ms(struct uart_port *port)
1443 struct uart_8250_port *up = up_to_u8250p(port);
1445 /* no MSR capabilities */
1446 if (up->bugs & UART_BUG_NOMSR)
1449 up->ier |= UART_IER_MSI;
1451 serial8250_rpm_get(up);
1452 serial_port_out(port, UART_IER, up->ier);
1453 serial8250_rpm_put(up);
1457 * serial8250_rx_chars: processes according to the passed in LSR
1458 * value, and returns the remaining LSR bits not handled
1459 * by this Rx routine.
1462 serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr)
1464 struct uart_port *port = &up->port;
1466 int max_count = 256;
1470 if (likely(lsr & UART_LSR_DR))
1471 ch = serial_in(up, UART_RX);
1474 * Intel 82571 has a Serial Over Lan device that will
1475 * set UART_LSR_BI without setting UART_LSR_DR when
1476 * it receives a break. To avoid reading from the
1477 * receive buffer without UART_LSR_DR bit set, we
1478 * just force the read character to be 0
1485 lsr |= up->lsr_saved_flags;
1486 up->lsr_saved_flags = 0;
1488 if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
1489 if (lsr & UART_LSR_BI) {
1490 lsr &= ~(UART_LSR_FE | UART_LSR_PE);
1493 * We do the SysRQ and SAK checking
1494 * here because otherwise the break
1495 * may get masked by ignore_status_mask
1496 * or read_status_mask.
1498 if (uart_handle_break(port))
1500 } else if (lsr & UART_LSR_PE)
1501 port->icount.parity++;
1502 else if (lsr & UART_LSR_FE)
1503 port->icount.frame++;
1504 if (lsr & UART_LSR_OE)
1505 port->icount.overrun++;
1508 * Mask off conditions which should be ignored.
1510 lsr &= port->read_status_mask;
1512 if (lsr & UART_LSR_BI) {
1513 DEBUG_INTR("handling break....");
1515 } else if (lsr & UART_LSR_PE)
1517 else if (lsr & UART_LSR_FE)
1520 if (uart_handle_sysrq_char(port, ch))
1523 uart_insert_char(port, lsr, UART_LSR_OE, ch, flag);
1526 lsr = serial_in(up, UART_LSR);
1527 } while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (--max_count > 0));
1528 spin_unlock(&port->lock);
1529 tty_flip_buffer_push(&port->state->port);
1530 spin_lock(&port->lock);
1533 EXPORT_SYMBOL_GPL(serial8250_rx_chars);
1535 void serial8250_tx_chars(struct uart_8250_port *up)
1537 struct uart_port *port = &up->port;
1538 struct circ_buf *xmit = &port->state->xmit;
1542 serial_out(up, UART_TX, port->x_char);
1547 if (uart_tx_stopped(port)) {
1548 serial8250_stop_tx(port);
1551 if (uart_circ_empty(xmit)) {
1556 count = up->tx_loadsz;
1558 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
1559 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
1561 if (uart_circ_empty(xmit))
1563 if (up->capabilities & UART_CAP_HFIFO) {
1564 if ((serial_port_in(port, UART_LSR) & BOTH_EMPTY) !=
1568 } while (--count > 0);
1570 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1571 uart_write_wakeup(port);
1573 DEBUG_INTR("THRE...");
1576 * With RPM enabled, we have to wait until the FIFO is empty before the
1577 * HW can go idle. So we get here once again with empty FIFO and disable
1578 * the interrupt and RPM in __stop_tx()
1580 if (uart_circ_empty(xmit) && !(up->capabilities & UART_CAP_RPM))
1583 EXPORT_SYMBOL_GPL(serial8250_tx_chars);
1585 /* Caller holds uart port lock */
1586 unsigned int serial8250_modem_status(struct uart_8250_port *up)
1588 struct uart_port *port = &up->port;
1589 unsigned int status = serial_in(up, UART_MSR);
1591 status |= up->msr_saved_flags;
1592 up->msr_saved_flags = 0;
1593 if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
1594 port->state != NULL) {
1595 if (status & UART_MSR_TERI)
1597 if (status & UART_MSR_DDSR)
1599 if (status & UART_MSR_DDCD)
1600 uart_handle_dcd_change(port, status & UART_MSR_DCD);
1601 if (status & UART_MSR_DCTS)
1602 uart_handle_cts_change(port, status & UART_MSR_CTS);
1604 wake_up_interruptible(&port->state->port.delta_msr_wait);
1609 EXPORT_SYMBOL_GPL(serial8250_modem_status);
1612 * This handles the interrupt from one port.
1614 int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
1616 unsigned char status;
1617 unsigned long flags;
1618 struct uart_8250_port *up = up_to_u8250p(port);
1621 if (iir & UART_IIR_NO_INT)
1624 spin_lock_irqsave(&port->lock, flags);
1626 status = serial_port_in(port, UART_LSR);
1628 DEBUG_INTR("status = %x...", status);
1630 if (status & (UART_LSR_DR | UART_LSR_BI)) {
1632 dma_err = up->dma->rx_dma(up, iir);
1634 if (!up->dma || dma_err)
1635 status = serial8250_rx_chars(up, status);
1637 serial8250_modem_status(up);
1638 if ((!up->dma || (up->dma && up->dma->tx_err)) &&
1639 (status & UART_LSR_THRE))
1640 serial8250_tx_chars(up);
1642 spin_unlock_irqrestore(&port->lock, flags);
1645 EXPORT_SYMBOL_GPL(serial8250_handle_irq);
1647 static int serial8250_default_handle_irq(struct uart_port *port)
1649 struct uart_8250_port *up = up_to_u8250p(port);
1653 serial8250_rpm_get(up);
1655 iir = serial_port_in(port, UART_IIR);
1656 ret = serial8250_handle_irq(port, iir);
1658 serial8250_rpm_put(up);
1663 * These Exar UARTs have an extra interrupt indicator that could
1664 * fire for a few unimplemented interrupts. One of which is a
1665 * wakeup event when coming out of sleep. Put this here just
1666 * to be on the safe side that these interrupts don't go unhandled.
1668 static int exar_handle_irq(struct uart_port *port)
1670 unsigned char int0, int1, int2, int3;
1671 unsigned int iir = serial_port_in(port, UART_IIR);
1674 ret = serial8250_handle_irq(port, iir);
1676 if ((port->type == PORT_XR17V35X) ||
1677 (port->type == PORT_XR17D15X)) {
1678 int0 = serial_port_in(port, 0x80);
1679 int1 = serial_port_in(port, 0x81);
1680 int2 = serial_port_in(port, 0x82);
1681 int3 = serial_port_in(port, 0x83);
1688 * This is the serial driver's interrupt routine.
1690 * Arjan thinks the old way was overly complex, so it got simplified.
1691 * Alan disagrees, saying that need the complexity to handle the weird
1692 * nature of ISA shared interrupts. (This is a special exception.)
1694 * In order to handle ISA shared interrupts properly, we need to check
1695 * that all ports have been serviced, and therefore the ISA interrupt
1696 * line has been de-asserted.
1698 * This means we need to loop through all ports. checking that they
1699 * don't have an interrupt pending.
1701 static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
1703 struct irq_info *i = dev_id;
1704 struct list_head *l, *end = NULL;
1705 int pass_counter = 0, handled = 0;
1707 DEBUG_INTR("serial8250_interrupt(%d)...", irq);
1709 spin_lock(&i->lock);
1713 struct uart_8250_port *up;
1714 struct uart_port *port;
1716 up = list_entry(l, struct uart_8250_port, list);
1719 if (port->handle_irq(port)) {
1722 } else if (end == NULL)
1727 if (l == i->head && pass_counter++ > PASS_LIMIT) {
1728 /* If we hit this, we're dead. */
1729 printk_ratelimited(KERN_ERR
1730 "serial8250: too much work for irq%d\n", irq);
1735 spin_unlock(&i->lock);
1737 DEBUG_INTR("end.\n");
1739 return IRQ_RETVAL(handled);
1743 * To support ISA shared interrupts, we need to have one interrupt
1744 * handler that ensures that the IRQ line has been deasserted
1745 * before returning. Failing to do this will result in the IRQ
1746 * line being stuck active, and, since ISA irqs are edge triggered,
1747 * no more IRQs will be seen.
1749 static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up)
1751 spin_lock_irq(&i->lock);
1753 if (!list_empty(i->head)) {
1754 if (i->head == &up->list)
1755 i->head = i->head->next;
1756 list_del(&up->list);
1758 BUG_ON(i->head != &up->list);
1761 spin_unlock_irq(&i->lock);
1762 /* List empty so throw away the hash node */
1763 if (i->head == NULL) {
1764 hlist_del(&i->node);
1769 static int serial_link_irq_chain(struct uart_8250_port *up)
1771 struct hlist_head *h;
1772 struct hlist_node *n;
1774 int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0;
1776 mutex_lock(&hash_mutex);
1778 h = &irq_lists[up->port.irq % NR_IRQ_HASH];
1780 hlist_for_each(n, h) {
1781 i = hlist_entry(n, struct irq_info, node);
1782 if (i->irq == up->port.irq)
1787 i = kzalloc(sizeof(struct irq_info), GFP_KERNEL);
1789 mutex_unlock(&hash_mutex);
1792 spin_lock_init(&i->lock);
1793 i->irq = up->port.irq;
1794 hlist_add_head(&i->node, h);
1796 mutex_unlock(&hash_mutex);
1798 spin_lock_irq(&i->lock);
1801 list_add(&up->list, i->head);
1802 spin_unlock_irq(&i->lock);
1806 INIT_LIST_HEAD(&up->list);
1807 i->head = &up->list;
1808 spin_unlock_irq(&i->lock);
1809 irq_flags |= up->port.irqflags;
1810 ret = request_irq(up->port.irq, serial8250_interrupt,
1811 irq_flags, "serial", i);
1813 serial_do_unlink(i, up);
1819 static void serial_unlink_irq_chain(struct uart_8250_port *up)
1822 * yes, some broken gcc emit "warning: 'i' may be used uninitialized"
1823 * but no, we are not going to take a patch that assigns NULL below.
1826 struct hlist_node *n;
1827 struct hlist_head *h;
1829 mutex_lock(&hash_mutex);
1831 h = &irq_lists[up->port.irq % NR_IRQ_HASH];
1833 hlist_for_each(n, h) {
1834 i = hlist_entry(n, struct irq_info, node);
1835 if (i->irq == up->port.irq)
1840 BUG_ON(i->head == NULL);
1842 if (list_empty(i->head))
1843 free_irq(up->port.irq, i);
1845 serial_do_unlink(i, up);
1846 mutex_unlock(&hash_mutex);
1850 * This function is used to handle ports that do not have an
1851 * interrupt. This doesn't work very well for 16450's, but gives
1852 * barely passable results for a 16550A. (Although at the expense
1853 * of much CPU overhead).
1855 static void serial8250_timeout(unsigned long data)
1857 struct uart_8250_port *up = (struct uart_8250_port *)data;
1859 up->port.handle_irq(&up->port);
1860 mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port));
1863 static void serial8250_backup_timeout(unsigned long data)
1865 struct uart_8250_port *up = (struct uart_8250_port *)data;
1866 unsigned int iir, ier = 0, lsr;
1867 unsigned long flags;
1869 spin_lock_irqsave(&up->port.lock, flags);
1872 * Must disable interrupts or else we risk racing with the interrupt
1876 ier = serial_in(up, UART_IER);
1877 serial_out(up, UART_IER, 0);
1880 iir = serial_in(up, UART_IIR);
1883 * This should be a safe test for anyone who doesn't trust the
1884 * IIR bits on their UART, but it's specifically designed for
1885 * the "Diva" UART used on the management processor on many HP
1886 * ia64 and parisc boxes.
1888 lsr = serial_in(up, UART_LSR);
1889 up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
1890 if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
1891 (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) &&
1892 (lsr & UART_LSR_THRE)) {
1893 iir &= ~(UART_IIR_ID | UART_IIR_NO_INT);
1894 iir |= UART_IIR_THRI;
1897 if (!(iir & UART_IIR_NO_INT))
1898 serial8250_tx_chars(up);
1901 serial_out(up, UART_IER, ier);
1903 spin_unlock_irqrestore(&up->port.lock, flags);
1905 /* Standard timer interval plus 0.2s to keep the port running */
1906 mod_timer(&up->timer,
1907 jiffies + uart_poll_timeout(&up->port) + HZ / 5);
1910 static unsigned int serial8250_tx_empty(struct uart_port *port)
1912 struct uart_8250_port *up = up_to_u8250p(port);
1913 unsigned long flags;
1916 serial8250_rpm_get(up);
1918 spin_lock_irqsave(&port->lock, flags);
1919 lsr = serial_port_in(port, UART_LSR);
1920 up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
1921 spin_unlock_irqrestore(&port->lock, flags);
1923 serial8250_rpm_put(up);
1925 return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0;
1928 static unsigned int serial8250_get_mctrl(struct uart_port *port)
1930 struct uart_8250_port *up = up_to_u8250p(port);
1931 unsigned int status;
1934 serial8250_rpm_get(up);
1935 status = serial8250_modem_status(up);
1936 serial8250_rpm_put(up);
1939 if (status & UART_MSR_DCD)
1941 if (status & UART_MSR_RI)
1943 if (status & UART_MSR_DSR)
1945 if (status & UART_MSR_CTS)
1950 void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl)
1952 struct uart_8250_port *up = up_to_u8250p(port);
1953 unsigned char mcr = 0;
1955 if (mctrl & TIOCM_RTS)
1956 mcr |= UART_MCR_RTS;
1957 if (mctrl & TIOCM_DTR)
1958 mcr |= UART_MCR_DTR;
1959 if (mctrl & TIOCM_OUT1)
1960 mcr |= UART_MCR_OUT1;
1961 if (mctrl & TIOCM_OUT2)
1962 mcr |= UART_MCR_OUT2;
1963 if (mctrl & TIOCM_LOOP)
1964 mcr |= UART_MCR_LOOP;
1966 mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
1968 serial_port_out(port, UART_MCR, mcr);
1970 EXPORT_SYMBOL_GPL(serial8250_do_set_mctrl);
1972 static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
1974 if (port->set_mctrl)
1975 return port->set_mctrl(port, mctrl);
1976 return serial8250_do_set_mctrl(port, mctrl);
1979 static void serial8250_break_ctl(struct uart_port *port, int break_state)
1981 struct uart_8250_port *up = up_to_u8250p(port);
1982 unsigned long flags;
1984 serial8250_rpm_get(up);
1985 spin_lock_irqsave(&port->lock, flags);
1986 if (break_state == -1)
1987 up->lcr |= UART_LCR_SBC;
1989 up->lcr &= ~UART_LCR_SBC;
1990 serial_port_out(port, UART_LCR, up->lcr);
1991 spin_unlock_irqrestore(&port->lock, flags);
1992 serial8250_rpm_put(up);
1996 * Wait for transmitter & holding register to empty
1998 static void wait_for_xmitr(struct uart_8250_port *up, int bits)
2000 unsigned int status, tmout = 10000;
2002 /* Wait up to 10ms for the character(s) to be sent. */
2004 status = serial_in(up, UART_LSR);
2006 up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
2008 if ((status & bits) == bits)
2015 /* Wait up to 1s for flow control if necessary */
2016 if (up->port.flags & UPF_CONS_FLOW) {
2018 for (tmout = 1000000; tmout; tmout--) {
2019 unsigned int msr = serial_in(up, UART_MSR);
2020 up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
2021 if (msr & UART_MSR_CTS)
2024 touch_nmi_watchdog();
2029 #ifdef CONFIG_CONSOLE_POLL
2031 * Console polling routines for writing and reading from the uart while
2032 * in an interrupt or debug context.
2035 static int serial8250_get_poll_char(struct uart_port *port)
2037 struct uart_8250_port *up = up_to_u8250p(port);
2041 serial8250_rpm_get(up);
2043 lsr = serial_port_in(port, UART_LSR);
2045 if (!(lsr & UART_LSR_DR)) {
2046 status = NO_POLL_CHAR;
2050 status = serial_port_in(port, UART_RX);
2052 serial8250_rpm_put(up);
2057 static void serial8250_put_poll_char(struct uart_port *port,
2061 struct uart_8250_port *up = up_to_u8250p(port);
2063 serial8250_rpm_get(up);
2065 * First save the IER then disable the interrupts
2067 ier = serial_port_in(port, UART_IER);
2068 if (up->capabilities & UART_CAP_UUE)
2069 serial_port_out(port, UART_IER, UART_IER_UUE);
2071 serial_port_out(port, UART_IER, 0);
2073 wait_for_xmitr(up, BOTH_EMPTY);
2075 * Send the character out.
2077 serial_port_out(port, UART_TX, c);
2080 * Finally, wait for transmitter to become empty
2081 * and restore the IER
2083 wait_for_xmitr(up, BOTH_EMPTY);
2084 serial_port_out(port, UART_IER, ier);
2085 serial8250_rpm_put(up);
2088 #endif /* CONFIG_CONSOLE_POLL */
2090 int serial8250_do_startup(struct uart_port *port)
2092 struct uart_8250_port *up = up_to_u8250p(port);
2093 unsigned long flags;
2094 unsigned char lsr, iir;
2097 if (port->type == PORT_8250_CIR)
2100 if (!port->fifosize)
2101 port->fifosize = uart_config[port->type].fifo_size;
2103 up->tx_loadsz = uart_config[port->type].tx_loadsz;
2104 if (!up->capabilities)
2105 up->capabilities = uart_config[port->type].flags;
2108 if (port->iotype != up->cur_iotype)
2109 set_io_from_upio(port);
2111 serial8250_rpm_get(up);
2112 if (port->type == PORT_16C950) {
2113 /* Wake up and initialize UART */
2115 serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
2116 serial_port_out(port, UART_EFR, UART_EFR_ECB);
2117 serial_port_out(port, UART_IER, 0);
2118 serial_port_out(port, UART_LCR, 0);
2119 serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
2120 serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
2121 serial_port_out(port, UART_EFR, UART_EFR_ECB);
2122 serial_port_out(port, UART_LCR, 0);
2125 #ifdef CONFIG_SERIAL_8250_RSA
2127 * If this is an RSA port, see if we can kick it up to the
2128 * higher speed clock.
2133 * Clear the FIFO buffers and disable them.
2134 * (they will be reenabled in set_termios())
2136 serial8250_clear_fifos(up);
2139 * Clear the interrupt registers.
2141 if (serial_port_in(port, UART_LSR) & UART_LSR_DR)
2142 serial_port_in(port, UART_RX);
2143 serial_port_in(port, UART_IIR);
2144 serial_port_in(port, UART_MSR);
2147 * At this point, there's no way the LSR could still be 0xff;
2148 * if it is, then bail out, because there's likely no UART
2151 if (!(port->flags & UPF_BUGGY_UART) &&
2152 (serial_port_in(port, UART_LSR) == 0xff)) {
2153 printk_ratelimited(KERN_INFO "ttyS%d: LSR safety check engaged!\n",
2154 serial_index(port));
2160 * For a XR16C850, we need to set the trigger levels
2162 if (port->type == PORT_16850) {
2165 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
2167 fctr = serial_in(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
2168 serial_port_out(port, UART_FCTR,
2169 fctr | UART_FCTR_TRGD | UART_FCTR_RX);
2170 serial_port_out(port, UART_TRG, UART_TRG_96);
2171 serial_port_out(port, UART_FCTR,
2172 fctr | UART_FCTR_TRGD | UART_FCTR_TX);
2173 serial_port_out(port, UART_TRG, UART_TRG_96);
2175 serial_port_out(port, UART_LCR, 0);
2181 * Test for UARTs that do not reassert THRE when the
2182 * transmitter is idle and the interrupt has already
2183 * been cleared. Real 16550s should always reassert
2184 * this interrupt whenever the transmitter is idle and
2185 * the interrupt is enabled. Delays are necessary to
2186 * allow register changes to become visible.
2188 spin_lock_irqsave(&port->lock, flags);
2189 if (up->port.irqflags & IRQF_SHARED)
2190 disable_irq_nosync(port->irq);
2192 wait_for_xmitr(up, UART_LSR_THRE);
2193 serial_port_out_sync(port, UART_IER, UART_IER_THRI);
2194 udelay(1); /* allow THRE to set */
2195 iir1 = serial_port_in(port, UART_IIR);
2196 serial_port_out(port, UART_IER, 0);
2197 serial_port_out_sync(port, UART_IER, UART_IER_THRI);
2198 udelay(1); /* allow a working UART time to re-assert THRE */
2199 iir = serial_port_in(port, UART_IIR);
2200 serial_port_out(port, UART_IER, 0);
2202 if (port->irqflags & IRQF_SHARED)
2203 enable_irq(port->irq);
2204 spin_unlock_irqrestore(&port->lock, flags);
2207 * If the interrupt is not reasserted, or we otherwise
2208 * don't trust the iir, setup a timer to kick the UART
2209 * on a regular basis.
2211 if ((!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) ||
2212 up->port.flags & UPF_BUG_THRE) {
2213 up->bugs |= UART_BUG_THRE;
2214 pr_debug("ttyS%d - using backup timer\n",
2215 serial_index(port));
2220 * The above check will only give an accurate result the first time
2221 * the port is opened so this value needs to be preserved.
2223 if (up->bugs & UART_BUG_THRE) {
2224 up->timer.function = serial8250_backup_timeout;
2225 up->timer.data = (unsigned long)up;
2226 mod_timer(&up->timer, jiffies +
2227 uart_poll_timeout(port) + HZ / 5);
2231 * If the "interrupt" for this port doesn't correspond with any
2232 * hardware interrupt, we use a timer-based system. The original
2233 * driver used to do this with IRQ0.
2236 up->timer.data = (unsigned long)up;
2237 mod_timer(&up->timer, jiffies + uart_poll_timeout(port));
2239 retval = serial_link_irq_chain(up);
2245 * Now, initialize the UART
2247 serial_port_out(port, UART_LCR, UART_LCR_WLEN8);
2249 spin_lock_irqsave(&port->lock, flags);
2250 if (up->port.flags & UPF_FOURPORT) {
2252 up->port.mctrl |= TIOCM_OUT1;
2255 * Most PC uarts need OUT2 raised to enable interrupts.
2258 up->port.mctrl |= TIOCM_OUT2;
2260 serial8250_set_mctrl(port, port->mctrl);
2262 /* Serial over Lan (SoL) hack:
2263 Intel 8257x Gigabit ethernet chips have a
2264 16550 emulation, to be used for Serial Over Lan.
2265 Those chips take a longer time than a normal
2266 serial device to signalize that a transmission
2267 data was queued. Due to that, the above test generally
2268 fails. One solution would be to delay the reading of
2269 iir. However, this is not reliable, since the timeout
2270 is variable. So, let's just don't test if we receive
2271 TX irq. This way, we'll never enable UART_BUG_TXEN.
2273 if (skip_txen_test || up->port.flags & UPF_NO_TXEN_TEST)
2274 goto dont_test_tx_en;
2277 * Do a quick test to see if we receive an
2278 * interrupt when we enable the TX irq.
2280 serial_port_out(port, UART_IER, UART_IER_THRI);
2281 lsr = serial_port_in(port, UART_LSR);
2282 iir = serial_port_in(port, UART_IIR);
2283 serial_port_out(port, UART_IER, 0);
2285 if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
2286 if (!(up->bugs & UART_BUG_TXEN)) {
2287 up->bugs |= UART_BUG_TXEN;
2288 pr_debug("ttyS%d - enabling bad tx status workarounds\n",
2289 serial_index(port));
2292 up->bugs &= ~UART_BUG_TXEN;
2296 spin_unlock_irqrestore(&port->lock, flags);
2299 * Clear the interrupt registers again for luck, and clear the
2300 * saved flags to avoid getting false values from polling
2301 * routines or the previous session.
2303 if (serial_port_in(port, UART_LSR) & UART_LSR_DR)
2304 serial_port_in(port, UART_RX);
2305 serial_port_in(port, UART_IIR);
2306 serial_port_in(port, UART_MSR);
2307 up->lsr_saved_flags = 0;
2308 up->msr_saved_flags = 0;
2311 * Request DMA channels for both RX and TX.
2314 retval = serial8250_request_dma(up);
2316 pr_warn_ratelimited("ttyS%d - failed to request DMA\n",
2317 serial_index(port));
2323 * Finally, enable interrupts. Note: Modem status interrupts
2324 * are set via set_termios(), which will be occurring imminently
2325 * anyway, so we don't enable them here.
2327 up->ier = UART_IER_RLSI | UART_IER_RDI;
2328 serial_port_out(port, UART_IER, up->ier);
2330 if (port->flags & UPF_FOURPORT) {
2333 * Enable interrupts on the AST Fourport board
2335 icp = (port->iobase & 0xfe0) | 0x01f;
2341 serial8250_rpm_put(up);
2344 EXPORT_SYMBOL_GPL(serial8250_do_startup);
2346 static int serial8250_startup(struct uart_port *port)
2349 return port->startup(port);
2350 return serial8250_do_startup(port);
2353 void serial8250_do_shutdown(struct uart_port *port)
2355 struct uart_8250_port *up = up_to_u8250p(port);
2356 unsigned long flags;
2358 serial8250_rpm_get(up);
2360 * Disable interrupts from this port
2363 serial_port_out(port, UART_IER, 0);
2366 serial8250_release_dma(up);
2368 spin_lock_irqsave(&port->lock, flags);
2369 if (port->flags & UPF_FOURPORT) {
2370 /* reset interrupts on the AST Fourport board */
2371 inb((port->iobase & 0xfe0) | 0x1f);
2372 port->mctrl |= TIOCM_OUT1;
2374 port->mctrl &= ~TIOCM_OUT2;
2376 serial8250_set_mctrl(port, port->mctrl);
2377 spin_unlock_irqrestore(&port->lock, flags);
2380 * Disable break condition and FIFOs
2382 serial_port_out(port, UART_LCR,
2383 serial_port_in(port, UART_LCR) & ~UART_LCR_SBC);
2384 serial8250_clear_fifos(up);
2386 #ifdef CONFIG_SERIAL_8250_RSA
2388 * Reset the RSA board back to 115kbps compat mode.
2394 * Read data port to reset things, and then unlink from
2397 if (serial_port_in(port, UART_LSR) & UART_LSR_DR)
2398 serial_port_in(port, UART_RX);
2399 serial8250_rpm_put(up);
2401 del_timer_sync(&up->timer);
2402 up->timer.function = serial8250_timeout;
2404 serial_unlink_irq_chain(up);
2406 EXPORT_SYMBOL_GPL(serial8250_do_shutdown);
2408 static void serial8250_shutdown(struct uart_port *port)
2411 port->shutdown(port);
2413 serial8250_do_shutdown(port);
2416 static unsigned int serial8250_get_divisor(struct uart_8250_port *up, unsigned int baud)
2418 struct uart_port *port = &up->port;
2422 * Handle magic divisors for baud rates above baud_base on
2423 * SMSC SuperIO chips.
2425 if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
2426 baud == (port->uartclk/4))
2428 else if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
2429 baud == (port->uartclk/8))
2432 quot = uart_get_divisor(port, baud);
2435 * Oxford Semi 952 rev B workaround
2437 if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
2443 static unsigned char serial8250_compute_lcr(struct uart_8250_port *up,
2448 switch (c_cflag & CSIZE) {
2450 cval = UART_LCR_WLEN5;
2453 cval = UART_LCR_WLEN6;
2456 cval = UART_LCR_WLEN7;
2460 cval = UART_LCR_WLEN8;
2464 if (c_cflag & CSTOPB)
2465 cval |= UART_LCR_STOP;
2466 if (c_cflag & PARENB) {
2467 cval |= UART_LCR_PARITY;
2468 if (up->bugs & UART_BUG_PARITY)
2469 up->fifo_bug = true;
2471 if (!(c_cflag & PARODD))
2472 cval |= UART_LCR_EPAR;
2474 if (c_cflag & CMSPAR)
2475 cval |= UART_LCR_SPAR;
2482 serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
2483 struct ktermios *old)
2485 struct uart_8250_port *up = up_to_u8250p(port);
2487 unsigned long flags;
2488 unsigned int baud, quot;
2490 cval = serial8250_compute_lcr(up, termios->c_cflag);
2493 * Ask the core to calculate the divisor for us.
2495 baud = uart_get_baud_rate(port, termios, old,
2496 port->uartclk / 16 / 0xffff,
2497 port->uartclk / 16);
2498 quot = serial8250_get_divisor(up, baud);
2500 if (up->capabilities & UART_CAP_FIFO && port->fifosize > 1) {
2501 /* NOTE: If fifo_bug is not set, a user can set RX_trigger. */
2502 if ((baud < 2400 && !up->dma) || up->fifo_bug) {
2503 up->fcr &= ~UART_FCR_TRIGGER_MASK;
2504 up->fcr |= UART_FCR_TRIGGER_1;
2509 * MCR-based auto flow control. When AFE is enabled, RTS will be
2510 * deasserted when the receive FIFO contains more characters than
2511 * the trigger, or the MCR RTS bit is cleared. In the case where
2512 * the remote UART is not using CTS auto flow control, we must
2513 * have sufficient FIFO entries for the latency of the remote
2514 * UART to respond. IOW, at least 32 bytes of FIFO.
2516 if (up->capabilities & UART_CAP_AFE && port->fifosize >= 32) {
2517 up->mcr &= ~UART_MCR_AFE;
2518 if (termios->c_cflag & CRTSCTS)
2519 up->mcr |= UART_MCR_AFE;
2523 * Ok, we're now changing the port state. Do it with
2524 * interrupts disabled.
2526 serial8250_rpm_get(up);
2527 spin_lock_irqsave(&port->lock, flags);
2530 * Update the per-port timeout.
2532 uart_update_timeout(port, termios->c_cflag, baud);
2534 port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
2535 if (termios->c_iflag & INPCK)
2536 port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
2537 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
2538 port->read_status_mask |= UART_LSR_BI;
2541 * Characteres to ignore
2543 port->ignore_status_mask = 0;
2544 if (termios->c_iflag & IGNPAR)
2545 port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
2546 if (termios->c_iflag & IGNBRK) {
2547 port->ignore_status_mask |= UART_LSR_BI;
2549 * If we're ignoring parity and break indicators,
2550 * ignore overruns too (for real raw support).
2552 if (termios->c_iflag & IGNPAR)
2553 port->ignore_status_mask |= UART_LSR_OE;
2557 * ignore all characters if CREAD is not set
2559 if ((termios->c_cflag & CREAD) == 0)
2560 port->ignore_status_mask |= UART_LSR_DR;
2563 * CTS flow control flag and modem status interrupts
2565 up->ier &= ~UART_IER_MSI;
2566 if (!(up->bugs & UART_BUG_NOMSR) &&
2567 UART_ENABLE_MS(&up->port, termios->c_cflag))
2568 up->ier |= UART_IER_MSI;
2569 if (up->capabilities & UART_CAP_UUE)
2570 up->ier |= UART_IER_UUE;
2571 if (up->capabilities & UART_CAP_RTOIE)
2572 up->ier |= UART_IER_RTOIE;
2574 serial_port_out(port, UART_IER, up->ier);
2576 if (up->capabilities & UART_CAP_EFR) {
2577 unsigned char efr = 0;
2579 * TI16C752/Startech hardware flow control. FIXME:
2580 * - TI16C752 requires control thresholds to be set.
2581 * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
2583 if (termios->c_cflag & CRTSCTS)
2584 efr |= UART_EFR_CTS;
2586 serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
2587 if (port->flags & UPF_EXAR_EFR)
2588 serial_port_out(port, UART_XR_EFR, efr);
2590 serial_port_out(port, UART_EFR, efr);
2593 /* Workaround to enable 115200 baud on OMAP1510 internal ports */
2594 if (is_omap1510_8250(up)) {
2595 if (baud == 115200) {
2597 serial_port_out(port, UART_OMAP_OSC_12M_SEL, 1);
2599 serial_port_out(port, UART_OMAP_OSC_12M_SEL, 0);
2603 * For NatSemi, switch to bank 2 not bank 1, to avoid resetting EXCR2,
2604 * otherwise just set DLAB
2606 if (up->capabilities & UART_NATSEMI)
2607 serial_port_out(port, UART_LCR, 0xe0);
2609 serial_port_out(port, UART_LCR, cval | UART_LCR_DLAB);
2611 serial_dl_write(up, quot);
2614 * XR17V35x UARTs have an extra fractional divisor register (DLD)
2616 * We need to recalculate all of the registers, because DLM and DLL
2617 * are already rounded to a whole integer.
2619 * When recalculating we use a 32x clock instead of a 16x clock to
2620 * allow 1-bit for rounding in the fractional part.
2622 if (up->port.type == PORT_XR17V35X) {
2623 unsigned int baud_x32 = (port->uartclk * 2) / baud;
2624 u16 quot = baud_x32 / 32;
2625 u8 quot_frac = DIV_ROUND_CLOSEST(baud_x32 % 32, 2);
2627 serial_dl_write(up, quot);
2628 serial_port_out(port, 0x2, quot_frac & 0xf);
2632 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
2633 * is written without DLAB set, this mode will be disabled.
2635 if (port->type == PORT_16750)
2636 serial_port_out(port, UART_FCR, up->fcr);
2638 serial_port_out(port, UART_LCR, cval); /* reset DLAB */
2639 up->lcr = cval; /* Save LCR */
2640 if (port->type != PORT_16750) {
2641 /* emulated UARTs (Lucent Venus 167x) need two steps */
2642 if (up->fcr & UART_FCR_ENABLE_FIFO)
2643 serial_port_out(port, UART_FCR, UART_FCR_ENABLE_FIFO);
2644 serial_port_out(port, UART_FCR, up->fcr); /* set fcr */
2646 serial8250_set_mctrl(port, port->mctrl);
2647 spin_unlock_irqrestore(&port->lock, flags);
2648 serial8250_rpm_put(up);
2650 /* Don't rewrite B0 */
2651 if (tty_termios_baud_rate(termios))
2652 tty_termios_encode_baud_rate(termios, baud, baud);
2654 EXPORT_SYMBOL(serial8250_do_set_termios);
2657 serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
2658 struct ktermios *old)
2660 if (port->set_termios)
2661 port->set_termios(port, termios, old);
2663 serial8250_do_set_termios(port, termios, old);
2667 serial8250_set_ldisc(struct uart_port *port, struct ktermios *termios)
2669 if (termios->c_line == N_PPS) {
2670 port->flags |= UPF_HARDPPS_CD;
2671 spin_lock_irq(&port->lock);
2672 serial8250_enable_ms(port);
2673 spin_unlock_irq(&port->lock);
2675 port->flags &= ~UPF_HARDPPS_CD;
2676 if (!UART_ENABLE_MS(port, termios->c_cflag)) {
2677 spin_lock_irq(&port->lock);
2678 serial8250_disable_ms(port);
2679 spin_unlock_irq(&port->lock);
2685 void serial8250_do_pm(struct uart_port *port, unsigned int state,
2686 unsigned int oldstate)
2688 struct uart_8250_port *p = up_to_u8250p(port);
2690 serial8250_set_sleep(p, state != 0);
2692 EXPORT_SYMBOL(serial8250_do_pm);
2695 serial8250_pm(struct uart_port *port, unsigned int state,
2696 unsigned int oldstate)
2699 port->pm(port, state, oldstate);
2701 serial8250_do_pm(port, state, oldstate);
2704 static unsigned int serial8250_port_size(struct uart_8250_port *pt)
2706 if (pt->port.iotype == UPIO_AU) {
2707 if (pt->port.type == PORT_RT2880)
2711 if (is_omap1_8250(pt))
2712 return 0x16 << pt->port.regshift;
2714 return 8 << pt->port.regshift;
2718 * Resource handling.
2720 static int serial8250_request_std_resource(struct uart_8250_port *up)
2722 unsigned int size = serial8250_port_size(up);
2723 struct uart_port *port = &up->port;
2726 switch (port->iotype) {
2734 if (!request_mem_region(port->mapbase, size, "serial")) {
2739 if (port->flags & UPF_IOREMAP) {
2740 port->membase = ioremap_nocache(port->mapbase, size);
2741 if (!port->membase) {
2742 release_mem_region(port->mapbase, size);
2750 if (!request_region(port->iobase, size, "serial"))
2757 static void serial8250_release_std_resource(struct uart_8250_port *up)
2759 unsigned int size = serial8250_port_size(up);
2760 struct uart_port *port = &up->port;
2762 switch (port->iotype) {
2770 if (port->flags & UPF_IOREMAP) {
2771 iounmap(port->membase);
2772 port->membase = NULL;
2775 release_mem_region(port->mapbase, size);
2780 release_region(port->iobase, size);
2785 static int serial8250_request_rsa_resource(struct uart_8250_port *up)
2787 unsigned long start = UART_RSA_BASE << up->port.regshift;
2788 unsigned int size = 8 << up->port.regshift;
2789 struct uart_port *port = &up->port;
2792 switch (port->iotype) {
2795 start += port->iobase;
2796 if (request_region(start, size, "serial-rsa"))
2806 static void serial8250_release_rsa_resource(struct uart_8250_port *up)
2808 unsigned long offset = UART_RSA_BASE << up->port.regshift;
2809 unsigned int size = 8 << up->port.regshift;
2810 struct uart_port *port = &up->port;
2812 switch (port->iotype) {
2815 release_region(port->iobase + offset, size);
2820 static void serial8250_release_port(struct uart_port *port)
2822 struct uart_8250_port *up = up_to_u8250p(port);
2824 serial8250_release_std_resource(up);
2825 if (port->type == PORT_RSA)
2826 serial8250_release_rsa_resource(up);
2829 static int serial8250_request_port(struct uart_port *port)
2831 struct uart_8250_port *up = up_to_u8250p(port);
2834 if (port->type == PORT_8250_CIR)
2837 ret = serial8250_request_std_resource(up);
2838 if (ret == 0 && port->type == PORT_RSA) {
2839 ret = serial8250_request_rsa_resource(up);
2841 serial8250_release_std_resource(up);
2847 static int fcr_get_rxtrig_bytes(struct uart_8250_port *up)
2849 const struct serial8250_config *conf_type = &uart_config[up->port.type];
2850 unsigned char bytes;
2852 bytes = conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(up->fcr)];
2854 return bytes ? bytes : -EOPNOTSUPP;
2857 static int bytes_to_fcr_rxtrig(struct uart_8250_port *up, unsigned char bytes)
2859 const struct serial8250_config *conf_type = &uart_config[up->port.type];
2862 if (!conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(UART_FCR_R_TRIG_00)])
2865 for (i = 1; i < UART_FCR_R_TRIG_MAX_STATE; i++) {
2866 if (bytes < conf_type->rxtrig_bytes[i])
2867 /* Use the nearest lower value */
2868 return (--i) << UART_FCR_R_TRIG_SHIFT;
2871 return UART_FCR_R_TRIG_11;
2874 static int do_get_rxtrig(struct tty_port *port)
2876 struct uart_state *state = container_of(port, struct uart_state, port);
2877 struct uart_port *uport = state->uart_port;
2878 struct uart_8250_port *up =
2879 container_of(uport, struct uart_8250_port, port);
2881 if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1)
2884 return fcr_get_rxtrig_bytes(up);
2887 static int do_serial8250_get_rxtrig(struct tty_port *port)
2891 mutex_lock(&port->mutex);
2892 rxtrig_bytes = do_get_rxtrig(port);
2893 mutex_unlock(&port->mutex);
2895 return rxtrig_bytes;
2898 static ssize_t serial8250_get_attr_rx_trig_bytes(struct device *dev,
2899 struct device_attribute *attr, char *buf)
2901 struct tty_port *port = dev_get_drvdata(dev);
2904 rxtrig_bytes = do_serial8250_get_rxtrig(port);
2905 if (rxtrig_bytes < 0)
2906 return rxtrig_bytes;
2908 return snprintf(buf, PAGE_SIZE, "%d\n", rxtrig_bytes);
2911 static int do_set_rxtrig(struct tty_port *port, unsigned char bytes)
2913 struct uart_state *state = container_of(port, struct uart_state, port);
2914 struct uart_port *uport = state->uart_port;
2915 struct uart_8250_port *up =
2916 container_of(uport, struct uart_8250_port, port);
2919 if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1 ||
2923 rxtrig = bytes_to_fcr_rxtrig(up, bytes);
2927 serial8250_clear_fifos(up);
2928 up->fcr &= ~UART_FCR_TRIGGER_MASK;
2929 up->fcr |= (unsigned char)rxtrig;
2930 serial_out(up, UART_FCR, up->fcr);
2934 static int do_serial8250_set_rxtrig(struct tty_port *port, unsigned char bytes)
2938 mutex_lock(&port->mutex);
2939 ret = do_set_rxtrig(port, bytes);
2940 mutex_unlock(&port->mutex);
2945 static ssize_t serial8250_set_attr_rx_trig_bytes(struct device *dev,
2946 struct device_attribute *attr, const char *buf, size_t count)
2948 struct tty_port *port = dev_get_drvdata(dev);
2949 unsigned char bytes;
2955 ret = kstrtou8(buf, 10, &bytes);
2959 ret = do_serial8250_set_rxtrig(port, bytes);
2966 static DEVICE_ATTR(rx_trig_bytes, S_IRUSR | S_IWUSR | S_IRGRP,
2967 serial8250_get_attr_rx_trig_bytes,
2968 serial8250_set_attr_rx_trig_bytes);
2970 static struct attribute *serial8250_dev_attrs[] = {
2971 &dev_attr_rx_trig_bytes.attr,
2975 static struct attribute_group serial8250_dev_attr_group = {
2976 .attrs = serial8250_dev_attrs,
2979 static void register_dev_spec_attr_grp(struct uart_8250_port *up)
2981 const struct serial8250_config *conf_type = &uart_config[up->port.type];
2983 if (conf_type->rxtrig_bytes[0])
2984 up->port.attr_group = &serial8250_dev_attr_group;
2987 static void serial8250_config_port(struct uart_port *port, int flags)
2989 struct uart_8250_port *up = up_to_u8250p(port);
2990 int probeflags = PROBE_ANY;
2993 if (port->type == PORT_8250_CIR)
2997 * Find the region that we can probe for. This in turn
2998 * tells us whether we can probe for the type of port.
3000 ret = serial8250_request_std_resource(up);
3004 ret = serial8250_request_rsa_resource(up);
3006 probeflags &= ~PROBE_RSA;
3008 if (port->iotype != up->cur_iotype)
3009 set_io_from_upio(port);
3011 if (flags & UART_CONFIG_TYPE)
3012 autoconfig(up, probeflags);
3014 /* if access method is AU, it is a 16550 with a quirk */
3015 if (port->type == PORT_16550A && port->iotype == UPIO_AU)
3016 up->bugs |= UART_BUG_NOMSR;
3018 /* HW bugs may trigger IRQ while IIR == NO_INT */
3019 if (port->type == PORT_TEGRA)
3020 up->bugs |= UART_BUG_NOMSR;
3022 if (port->type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
3025 if (port->type != PORT_RSA && probeflags & PROBE_RSA)
3026 serial8250_release_rsa_resource(up);
3027 if (port->type == PORT_UNKNOWN)
3028 serial8250_release_std_resource(up);
3030 /* Fixme: probably not the best place for this */
3031 if ((port->type == PORT_XR17V35X) ||
3032 (port->type == PORT_XR17D15X))
3033 port->handle_irq = exar_handle_irq;
3035 register_dev_spec_attr_grp(up);
3036 up->fcr = uart_config[up->port.type].fcr;
3040 serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
3042 if (ser->irq >= nr_irqs || ser->irq < 0 ||
3043 ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
3044 ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
3045 ser->type == PORT_STARTECH)
3051 serial8250_type(struct uart_port *port)
3053 int type = port->type;
3055 if (type >= ARRAY_SIZE(uart_config))
3057 return uart_config[type].name;
3060 static struct uart_ops serial8250_pops = {
3061 .tx_empty = serial8250_tx_empty,
3062 .set_mctrl = serial8250_set_mctrl,
3063 .get_mctrl = serial8250_get_mctrl,
3064 .stop_tx = serial8250_stop_tx,
3065 .start_tx = serial8250_start_tx,
3066 .throttle = serial8250_throttle,
3067 .unthrottle = serial8250_unthrottle,
3068 .stop_rx = serial8250_stop_rx,
3069 .enable_ms = serial8250_enable_ms,
3070 .break_ctl = serial8250_break_ctl,
3071 .startup = serial8250_startup,
3072 .shutdown = serial8250_shutdown,
3073 .set_termios = serial8250_set_termios,
3074 .set_ldisc = serial8250_set_ldisc,
3075 .pm = serial8250_pm,
3076 .type = serial8250_type,
3077 .release_port = serial8250_release_port,
3078 .request_port = serial8250_request_port,
3079 .config_port = serial8250_config_port,
3080 .verify_port = serial8250_verify_port,
3081 #ifdef CONFIG_CONSOLE_POLL
3082 .poll_get_char = serial8250_get_poll_char,
3083 .poll_put_char = serial8250_put_poll_char,
3087 static struct uart_8250_port serial8250_ports[UART_NR];
3090 * serial8250_get_port - retrieve struct uart_8250_port
3091 * @line: serial line number
3093 * This function retrieves struct uart_8250_port for the specific line.
3094 * This struct *must* *not* be used to perform a 8250 or serial core operation
3095 * which is not accessible otherwise. Its only purpose is to make the struct
3096 * accessible to the runtime-pm callbacks for context suspend/restore.
3097 * The lock assumption made here is none because runtime-pm suspend/resume
3098 * callbacks should not be invoked if there is any operation performed on the
3101 struct uart_8250_port *serial8250_get_port(int line)
3103 return &serial8250_ports[line];
3105 EXPORT_SYMBOL_GPL(serial8250_get_port);
3107 static void (*serial8250_isa_config)(int port, struct uart_port *up,
3108 unsigned short *capabilities);
3110 void serial8250_set_isa_configurator(
3111 void (*v)(int port, struct uart_port *up, unsigned short *capabilities))
3113 serial8250_isa_config = v;
3115 EXPORT_SYMBOL(serial8250_set_isa_configurator);
3117 static void __init serial8250_isa_init_ports(void)
3119 struct uart_8250_port *up;
3120 static int first = 1;
3127 if (nr_uarts > UART_NR)
3130 for (i = 0; i < nr_uarts; i++) {
3131 struct uart_8250_port *up = &serial8250_ports[i];
3132 struct uart_port *port = &up->port;
3135 spin_lock_init(&port->lock);
3137 init_timer(&up->timer);
3138 up->timer.function = serial8250_timeout;
3139 up->cur_iotype = 0xFF;
3142 * ALPHA_KLUDGE_MCR needs to be killed.
3144 up->mcr_mask = ~ALPHA_KLUDGE_MCR;
3145 up->mcr_force = ALPHA_KLUDGE_MCR;
3147 port->ops = &serial8250_pops;
3151 irqflag = IRQF_SHARED;
3153 for (i = 0, up = serial8250_ports;
3154 i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
3156 struct uart_port *port = &up->port;
3158 port->iobase = old_serial_port[i].port;
3159 port->irq = irq_canonicalize(old_serial_port[i].irq);
3160 port->irqflags = old_serial_port[i].irqflags;
3161 port->uartclk = old_serial_port[i].baud_base * 16;
3162 port->flags = old_serial_port[i].flags;
3163 port->hub6 = old_serial_port[i].hub6;
3164 port->membase = old_serial_port[i].iomem_base;
3165 port->iotype = old_serial_port[i].io_type;
3166 port->regshift = old_serial_port[i].iomem_reg_shift;
3167 set_io_from_upio(port);
3168 port->irqflags |= irqflag;
3169 if (serial8250_isa_config != NULL)
3170 serial8250_isa_config(i, &up->port, &up->capabilities);
3176 serial8250_init_fixed_type_port(struct uart_8250_port *up, unsigned int type)
3178 up->port.type = type;
3179 if (!up->port.fifosize)
3180 up->port.fifosize = uart_config[type].fifo_size;
3182 up->tx_loadsz = uart_config[type].tx_loadsz;
3183 if (!up->capabilities)
3184 up->capabilities = uart_config[type].flags;
3188 serial8250_register_ports(struct uart_driver *drv, struct device *dev)
3192 for (i = 0; i < nr_uarts; i++) {
3193 struct uart_8250_port *up = &serial8250_ports[i];
3200 if (up->port.flags & UPF_FIXED_TYPE)
3201 serial8250_init_fixed_type_port(up, up->port.type);
3203 uart_add_one_port(drv, &up->port);
3207 #ifdef CONFIG_SERIAL_8250_CONSOLE
3209 static void serial8250_console_putchar(struct uart_port *port, int ch)
3211 struct uart_8250_port *up = up_to_u8250p(port);
3213 wait_for_xmitr(up, UART_LSR_THRE);
3214 serial_port_out(port, UART_TX, ch);
3218 * Print a string to the serial port trying not to disturb
3219 * any possible real use of the port...
3221 * The console_lock must be held when we get here.
3224 serial8250_console_write(struct console *co, const char *s, unsigned int count)
3226 struct uart_8250_port *up = &serial8250_ports[co->index];
3227 struct uart_port *port = &up->port;
3228 unsigned long flags;
3232 touch_nmi_watchdog();
3234 serial8250_rpm_get(up);
3238 else if (oops_in_progress)
3239 locked = spin_trylock_irqsave(&port->lock, flags);
3241 spin_lock_irqsave(&port->lock, flags);
3244 * First save the IER then disable the interrupts
3246 ier = serial_port_in(port, UART_IER);
3248 if (up->capabilities & UART_CAP_UUE)
3249 serial_port_out(port, UART_IER, UART_IER_UUE);
3251 serial_port_out(port, UART_IER, 0);
3253 uart_console_write(port, s, count, serial8250_console_putchar);
3256 * Finally, wait for transmitter to become empty
3257 * and restore the IER
3259 wait_for_xmitr(up, BOTH_EMPTY);
3260 serial_port_out(port, UART_IER, ier);
3263 * The receive handling will happen properly because the
3264 * receive ready bit will still be set; it is not cleared
3265 * on read. However, modem control will not, we must
3266 * call it if we have saved something in the saved flags
3267 * while processing with interrupts off.
3269 if (up->msr_saved_flags)
3270 serial8250_modem_status(up);
3273 spin_unlock_irqrestore(&port->lock, flags);
3274 serial8250_rpm_put(up);
3277 static int serial8250_console_setup(struct console *co, char *options)
3279 struct uart_port *port;
3286 * Check whether an invalid uart number has been specified, and
3287 * if so, search for the first available port that does have
3290 if (co->index >= nr_uarts)
3292 port = &serial8250_ports[co->index].port;
3293 if (!port->iobase && !port->membase)
3297 uart_parse_options(options, &baud, &parity, &bits, &flow);
3299 return uart_set_options(port, co, baud, parity, bits, flow);
3302 static int serial8250_console_early_setup(void)
3304 return serial8250_find_port_for_earlycon();
3307 static struct console serial8250_console = {
3309 .write = serial8250_console_write,
3310 .device = uart_console_device,
3311 .setup = serial8250_console_setup,
3312 .early_setup = serial8250_console_early_setup,
3313 .flags = CON_PRINTBUFFER | CON_ANYTIME,
3315 .data = &serial8250_reg,
3318 static int __init serial8250_console_init(void)
3320 serial8250_isa_init_ports();
3321 register_console(&serial8250_console);
3324 console_initcall(serial8250_console_init);
3326 int serial8250_find_port(struct uart_port *p)
3329 struct uart_port *port;
3331 for (line = 0; line < nr_uarts; line++) {
3332 port = &serial8250_ports[line].port;
3333 if (uart_match_port(p, port))
3339 #define SERIAL8250_CONSOLE &serial8250_console
3341 #define SERIAL8250_CONSOLE NULL
3344 static struct uart_driver serial8250_reg = {
3345 .owner = THIS_MODULE,
3346 .driver_name = "serial",
3350 .cons = SERIAL8250_CONSOLE,
3354 * early_serial_setup - early registration for 8250 ports
3356 * Setup an 8250 port structure prior to console initialisation. Use
3357 * after console initialisation will cause undefined behaviour.
3359 int __init early_serial_setup(struct uart_port *port)
3361 struct uart_port *p;
3363 if (port->line >= ARRAY_SIZE(serial8250_ports))
3366 serial8250_isa_init_ports();
3367 p = &serial8250_ports[port->line].port;
3368 p->iobase = port->iobase;
3369 p->membase = port->membase;
3371 p->irqflags = port->irqflags;
3372 p->uartclk = port->uartclk;
3373 p->fifosize = port->fifosize;
3374 p->regshift = port->regshift;
3375 p->iotype = port->iotype;
3376 p->flags = port->flags;
3377 p->mapbase = port->mapbase;
3378 p->private_data = port->private_data;
3379 p->type = port->type;
3380 p->line = port->line;
3382 set_io_from_upio(p);
3383 if (port->serial_in)
3384 p->serial_in = port->serial_in;
3385 if (port->serial_out)
3386 p->serial_out = port->serial_out;
3387 if (port->handle_irq)
3388 p->handle_irq = port->handle_irq;
3390 p->handle_irq = serial8250_default_handle_irq;
3396 * serial8250_suspend_port - suspend one serial port
3397 * @line: serial line number
3399 * Suspend one serial port.
3401 void serial8250_suspend_port(int line)
3403 uart_suspend_port(&serial8250_reg, &serial8250_ports[line].port);
3407 * serial8250_resume_port - resume one serial port
3408 * @line: serial line number
3410 * Resume one serial port.
3412 void serial8250_resume_port(int line)
3414 struct uart_8250_port *up = &serial8250_ports[line];
3415 struct uart_port *port = &up->port;
3417 if (up->capabilities & UART_NATSEMI) {
3418 /* Ensure it's still in high speed mode */
3419 serial_port_out(port, UART_LCR, 0xE0);
3421 ns16550a_goto_highspeed(up);
3423 serial_port_out(port, UART_LCR, 0);
3424 port->uartclk = 921600*16;
3426 uart_resume_port(&serial8250_reg, port);
3430 * Register a set of serial devices attached to a platform device. The
3431 * list is terminated with a zero flags entry, which means we expect
3432 * all entries to have at least UPF_BOOT_AUTOCONF set.
3434 static int serial8250_probe(struct platform_device *dev)
3436 struct plat_serial8250_port *p = dev_get_platdata(&dev->dev);
3437 struct uart_8250_port uart;
3438 int ret, i, irqflag = 0;
3440 memset(&uart, 0, sizeof(uart));
3443 irqflag = IRQF_SHARED;
3445 for (i = 0; p && p->flags != 0; p++, i++) {
3446 uart.port.iobase = p->iobase;
3447 uart.port.membase = p->membase;
3448 uart.port.irq = p->irq;
3449 uart.port.irqflags = p->irqflags;
3450 uart.port.uartclk = p->uartclk;
3451 uart.port.regshift = p->regshift;
3452 uart.port.iotype = p->iotype;
3453 uart.port.flags = p->flags;
3454 uart.port.mapbase = p->mapbase;
3455 uart.port.hub6 = p->hub6;
3456 uart.port.private_data = p->private_data;
3457 uart.port.type = p->type;
3458 uart.port.serial_in = p->serial_in;
3459 uart.port.serial_out = p->serial_out;
3460 uart.port.handle_irq = p->handle_irq;
3461 uart.port.handle_break = p->handle_break;
3462 uart.port.set_termios = p->set_termios;
3463 uart.port.pm = p->pm;
3464 uart.port.dev = &dev->dev;
3465 uart.port.irqflags |= irqflag;
3466 ret = serial8250_register_8250_port(&uart);
3468 dev_err(&dev->dev, "unable to register port at index %d "
3469 "(IO%lx MEM%llx IRQ%d): %d\n", i,
3470 p->iobase, (unsigned long long)p->mapbase,
3478 * Remove serial ports registered against a platform device.
3480 static int serial8250_remove(struct platform_device *dev)
3484 for (i = 0; i < nr_uarts; i++) {
3485 struct uart_8250_port *up = &serial8250_ports[i];
3487 if (up->port.dev == &dev->dev)
3488 serial8250_unregister_port(i);
3493 static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
3497 for (i = 0; i < UART_NR; i++) {
3498 struct uart_8250_port *up = &serial8250_ports[i];
3500 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
3501 uart_suspend_port(&serial8250_reg, &up->port);
3507 static int serial8250_resume(struct platform_device *dev)
3511 for (i = 0; i < UART_NR; i++) {
3512 struct uart_8250_port *up = &serial8250_ports[i];
3514 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
3515 serial8250_resume_port(i);
3521 static struct platform_driver serial8250_isa_driver = {
3522 .probe = serial8250_probe,
3523 .remove = serial8250_remove,
3524 .suspend = serial8250_suspend,
3525 .resume = serial8250_resume,
3527 .name = "serial8250",
3532 * This "device" covers _all_ ISA 8250-compatible serial devices listed
3533 * in the table in include/asm/serial.h
3535 static struct platform_device *serial8250_isa_devs;
3538 * serial8250_register_8250_port and serial8250_unregister_port allows for
3539 * 16x50 serial ports to be configured at run-time, to support PCMCIA
3540 * modems and PCI multiport cards.
3542 static DEFINE_MUTEX(serial_mutex);
3544 static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *port)
3549 * First, find a port entry which matches.
3551 for (i = 0; i < nr_uarts; i++)
3552 if (uart_match_port(&serial8250_ports[i].port, port))
3553 return &serial8250_ports[i];
3555 /* try line number first if still available */
3557 if (i < nr_uarts && serial8250_ports[i].port.type == PORT_UNKNOWN &&
3558 serial8250_ports[i].port.iobase == 0)
3559 return &serial8250_ports[i];
3561 * We didn't find a matching entry, so look for the first
3562 * free entry. We look for one which hasn't been previously
3563 * used (indicated by zero iobase).
3565 for (i = 0; i < nr_uarts; i++)
3566 if (serial8250_ports[i].port.type == PORT_UNKNOWN &&
3567 serial8250_ports[i].port.iobase == 0)
3568 return &serial8250_ports[i];
3571 * That also failed. Last resort is to find any entry which
3572 * doesn't have a real port associated with it.
3574 for (i = 0; i < nr_uarts; i++)
3575 if (serial8250_ports[i].port.type == PORT_UNKNOWN)
3576 return &serial8250_ports[i];
3582 * serial8250_register_8250_port - register a serial port
3583 * @up: serial port template
3585 * Configure the serial port specified by the request. If the
3586 * port exists and is in use, it is hung up and unregistered
3589 * The port is then probed and if necessary the IRQ is autodetected
3590 * If this fails an error is returned.
3592 * On success the port is ready to use and the line number is returned.
3594 int serial8250_register_8250_port(struct uart_8250_port *up)
3596 struct uart_8250_port *uart;
3599 if (up->port.uartclk == 0)
3602 mutex_lock(&serial_mutex);
3604 uart = serial8250_find_match_or_unused(&up->port);
3605 if (uart && uart->port.type != PORT_8250_CIR) {
3607 uart_remove_one_port(&serial8250_reg, &uart->port);
3609 uart->port.iobase = up->port.iobase;
3610 uart->port.membase = up->port.membase;
3611 uart->port.irq = up->port.irq;
3612 uart->port.irqflags = up->port.irqflags;
3613 uart->port.uartclk = up->port.uartclk;
3614 uart->port.fifosize = up->port.fifosize;
3615 uart->port.regshift = up->port.regshift;
3616 uart->port.iotype = up->port.iotype;
3617 uart->port.flags = up->port.flags | UPF_BOOT_AUTOCONF;
3618 uart->bugs = up->bugs;
3619 uart->port.mapbase = up->port.mapbase;
3620 uart->port.private_data = up->port.private_data;
3621 uart->port.fifosize = up->port.fifosize;
3622 uart->tx_loadsz = up->tx_loadsz;
3623 uart->capabilities = up->capabilities;
3624 uart->port.throttle = up->port.throttle;
3625 uart->port.unthrottle = up->port.unthrottle;
3626 uart->port.rs485_config = up->port.rs485_config;
3627 uart->port.rs485 = up->port.rs485;
3629 /* Take tx_loadsz from fifosize if it wasn't set separately */
3630 if (uart->port.fifosize && !uart->tx_loadsz)
3631 uart->tx_loadsz = uart->port.fifosize;
3634 uart->port.dev = up->port.dev;
3636 if (up->port.flags & UPF_FIXED_TYPE)
3637 serial8250_init_fixed_type_port(uart, up->port.type);
3639 set_io_from_upio(&uart->port);
3640 /* Possibly override default I/O functions. */
3641 if (up->port.serial_in)
3642 uart->port.serial_in = up->port.serial_in;
3643 if (up->port.serial_out)
3644 uart->port.serial_out = up->port.serial_out;
3645 if (up->port.handle_irq)
3646 uart->port.handle_irq = up->port.handle_irq;
3647 /* Possibly override set_termios call */
3648 if (up->port.set_termios)
3649 uart->port.set_termios = up->port.set_termios;
3650 if (up->port.set_mctrl)
3651 uart->port.set_mctrl = up->port.set_mctrl;
3652 if (up->port.startup)
3653 uart->port.startup = up->port.startup;
3654 if (up->port.shutdown)
3655 uart->port.shutdown = up->port.shutdown;
3657 uart->port.pm = up->port.pm;
3658 if (up->port.handle_break)
3659 uart->port.handle_break = up->port.handle_break;
3661 uart->dl_read = up->dl_read;
3663 uart->dl_write = up->dl_write;
3665 uart->dma = up->dma;
3666 if (!uart->dma->tx_dma)
3667 uart->dma->tx_dma = serial8250_tx_dma;
3668 if (!uart->dma->rx_dma)
3669 uart->dma->rx_dma = serial8250_rx_dma;
3672 if (serial8250_isa_config != NULL)
3673 serial8250_isa_config(0, &uart->port,
3674 &uart->capabilities);
3676 ret = uart_add_one_port(&serial8250_reg, &uart->port);
3678 ret = uart->port.line;
3680 mutex_unlock(&serial_mutex);
3684 EXPORT_SYMBOL(serial8250_register_8250_port);
3687 * serial8250_unregister_port - remove a 16x50 serial port at runtime
3688 * @line: serial line number
3690 * Remove one serial port. This may not be called from interrupt
3691 * context. We hand the port back to the our control.
3693 void serial8250_unregister_port(int line)
3695 struct uart_8250_port *uart = &serial8250_ports[line];
3697 mutex_lock(&serial_mutex);
3698 uart_remove_one_port(&serial8250_reg, &uart->port);
3699 if (serial8250_isa_devs) {
3700 uart->port.flags &= ~UPF_BOOT_AUTOCONF;
3701 uart->port.type = PORT_UNKNOWN;
3702 uart->port.dev = &serial8250_isa_devs->dev;
3703 uart->capabilities = uart_config[uart->port.type].flags;
3704 uart_add_one_port(&serial8250_reg, &uart->port);
3706 uart->port.dev = NULL;
3708 mutex_unlock(&serial_mutex);
3710 EXPORT_SYMBOL(serial8250_unregister_port);
3712 static int __init serial8250_init(void)
3716 serial8250_isa_init_ports();
3718 printk(KERN_INFO "Serial: 8250/16550 driver, "
3719 "%d ports, IRQ sharing %sabled\n", nr_uarts,
3720 share_irqs ? "en" : "dis");
3723 ret = sunserial_register_minors(&serial8250_reg, UART_NR);
3725 serial8250_reg.nr = UART_NR;
3726 ret = uart_register_driver(&serial8250_reg);
3731 ret = serial8250_pnp_init();
3733 goto unreg_uart_drv;
3735 serial8250_isa_devs = platform_device_alloc("serial8250",
3736 PLAT8250_DEV_LEGACY);
3737 if (!serial8250_isa_devs) {
3742 ret = platform_device_add(serial8250_isa_devs);
3746 serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);
3748 ret = platform_driver_register(&serial8250_isa_driver);
3752 platform_device_del(serial8250_isa_devs);
3754 platform_device_put(serial8250_isa_devs);
3756 serial8250_pnp_exit();
3759 sunserial_unregister_minors(&serial8250_reg, UART_NR);
3761 uart_unregister_driver(&serial8250_reg);
3767 static void __exit serial8250_exit(void)
3769 struct platform_device *isa_dev = serial8250_isa_devs;
3772 * This tells serial8250_unregister_port() not to re-register
3773 * the ports (thereby making serial8250_isa_driver permanently
3776 serial8250_isa_devs = NULL;
3778 platform_driver_unregister(&serial8250_isa_driver);
3779 platform_device_unregister(isa_dev);
3781 serial8250_pnp_exit();
3784 sunserial_unregister_minors(&serial8250_reg, UART_NR);
3786 uart_unregister_driver(&serial8250_reg);
3790 module_init(serial8250_init);
3791 module_exit(serial8250_exit);
3793 EXPORT_SYMBOL(serial8250_suspend_port);
3794 EXPORT_SYMBOL(serial8250_resume_port);
3796 MODULE_LICENSE("GPL");
3797 MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
3799 module_param(share_irqs, uint, 0644);
3800 MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"
3803 module_param(nr_uarts, uint, 0644);
3804 MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");
3806 module_param(skip_txen_test, uint, 0644);
3807 MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time");
3809 #ifdef CONFIG_SERIAL_8250_RSA
3810 module_param_array(probe_rsa, ulong, &probe_rsa_count, 0444);
3811 MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
3813 MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);
3815 #ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS
3817 /* This module was renamed to 8250_core in 3.7. Keep the old "8250" name
3818 * working as well for the module options so we don't break people. We
3819 * need to keep the names identical and the convenient macros will happily
3820 * refuse to let us do that by failing the build with redefinition errors
3821 * of global variables. So we stick them inside a dummy function to avoid
3822 * those conflicts. The options still get parsed, and the redefined
3823 * MODULE_PARAM_PREFIX lets us keep the "8250." syntax alive.
3825 * This is hacky. I'm sorry.
3827 static void __used s8250_options(void)
3829 #undef MODULE_PARAM_PREFIX
3830 #define MODULE_PARAM_PREFIX "8250_core."
3832 module_param_cb(share_irqs, ¶m_ops_uint, &share_irqs, 0644);
3833 module_param_cb(nr_uarts, ¶m_ops_uint, &nr_uarts, 0644);
3834 module_param_cb(skip_txen_test, ¶m_ops_uint, &skip_txen_test, 0644);
3835 #ifdef CONFIG_SERIAL_8250_RSA
3836 __module_param_call(MODULE_PARAM_PREFIX, probe_rsa,
3837 ¶m_array_ops, .arr = &__param_arr_probe_rsa,
3842 MODULE_ALIAS("8250_core");