/* * linux/drivers/char/8250.c * * Driver for 8250/16550-type serial ports * * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * * Copyright (C) 2001 Russell King. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * $Id: 8250.c,v 1.90 2002/07/28 10:03:27 rmk Exp $ * * A note about mapbase / membase * * mapbase is the physical address of the IO port. * membase is an 'ioremapped' cookie. */ #include <linux/config.h> #if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) #define SUPPORT_SYSRQ #endif #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/ioport.h> #include <linux/init.h> #include <linux/console.h> #include <linux/sysrq.h> #include <linux/mca.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/serial_reg.h> #include <linux/serial_core.h> #include <linux/serial.h> #include <linux/serial_8250.h> #include <asm/io.h> #include <asm/irq.h> #include "8250.h" /* * Configuration: * share_irqs - whether we pass SA_SHIRQ to request_irq(). This option * is unsafe when used on edge-triggered interrupts. */ static unsigned int share_irqs = SERIAL8250_SHARE_IRQS; /* * Debugging. */ #if 0 #define DEBUG_AUTOCONF(fmt...) printk(fmt) #else #define DEBUG_AUTOCONF(fmt...) do { } while (0) #endif #if 0 #define DEBUG_INTR(fmt...) printk(fmt) #else #define DEBUG_INTR(fmt...) do { } while (0) #endif #define PASS_LIMIT 256 /* * We default to IRQ0 for the "no irq" hack. Some * machine types want others as well - they're free * to redefine this in their header file. */ #define is_real_interrupt(irq) ((irq) != 0) #ifdef CONFIG_SERIAL_8250_DETECT_IRQ #define CONFIG_SERIAL_DETECT_IRQ 1 #endif #ifdef CONFIG_SERIAL_8250_MANY_PORTS #define CONFIG_SERIAL_MANY_PORTS 1 #endif /* * HUB6 is always on. This will be removed once the header * files have been cleaned. */ #define CONFIG_HUB6 1 #include <asm/serial.h> /* * SERIAL_PORT_DFNS tells us about built-in ports that have no * standard enumeration mechanism. Platforms that can find all * serial ports via mechanisms like ACPI or PCI need not supply it. */ #ifndef SERIAL_PORT_DFNS #define SERIAL_PORT_DFNS #endif static struct old_serial_port old_serial_port[] = { SERIAL_PORT_DFNS /* defined in asm/serial.h */ }; #define UART_NR CONFIG_SERIAL_8250_NR_UARTS #ifdef CONFIG_SERIAL_8250_RSA #define PORT_RSA_MAX 4 static unsigned long probe_rsa[PORT_RSA_MAX]; static unsigned int probe_rsa_count; #endif /* CONFIG_SERIAL_8250_RSA */ struct uart_8250_port { struct uart_port port; struct timer_list timer; /* "no irq" timer */ struct list_head list; /* ports on this IRQ */ unsigned short capabilities; /* port capabilities */ unsigned short bugs; /* port bugs */ unsigned int tx_loadsz; /* transmit fifo load size */ unsigned char acr; unsigned char ier; unsigned char lcr; unsigned char mcr; unsigned char mcr_mask; /* mask of user bits */ unsigned char mcr_force; /* mask of forced bits */ unsigned char lsr_break_flag; /* * We provide a per-port pm hook. */ void (*pm)(struct uart_port *port, unsigned int state, unsigned int old); }; struct irq_info { spinlock_t lock; struct list_head *head; }; static struct irq_info irq_lists[NR_IRQS]; /* * Here we define the default xmit fifo size used for each type of UART. */ static const struct serial8250_config uart_config[] = { [PORT_UNKNOWN] = { .name = "unknown", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_8250] = { .name = "8250", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16450] = { .name = "16450", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16550] = { .name = "16550", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16550A] = { .name = "16550A", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO, }, [PORT_CIRRUS] = { .name = "Cirrus", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16650] = { .name = "ST16650", .fifo_size = 1, .tx_loadsz = 1, .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_16650V2] = { .name = "ST16650V2", .fifo_size = 32, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_00, .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_16750] = { .name = "TI16750", .fifo_size = 64, .tx_loadsz = 64, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 | UART_FCR7_64BYTE, .flags = UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE, }, [PORT_STARTECH] = { .name = "Startech", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16C950] = { .name = "16C950/954", .fifo_size = 128, .tx_loadsz = 128, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO, }, [PORT_16654] = { .name = "ST16654", .fifo_size = 64, .tx_loadsz = 32, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_16850] = { .name = "XR16850", .fifo_size = 128, .tx_loadsz = 128, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_RSA] = { .name = "RSA", .fifo_size = 2048, .tx_loadsz = 2048, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11, .flags = UART_CAP_FIFO, }, [PORT_NS16550A] = { .name = "NS16550A", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_NATSEMI, }, [PORT_XSCALE] = { .name = "XScale", .fifo_size = 32, .tx_loadsz = 32, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_UUE, }, }; static _INLINE_ unsigned int serial_in(struct uart_8250_port *up, int offset) { offset <<= up->port.regshift; switch (up->port.iotype) { case UPIO_HUB6: outb(up->port.hub6 - 1 + offset, up->port.iobase); return inb(up->port.iobase + 1); case UPIO_MEM: return readb(up->port.membase + offset); case UPIO_MEM32: return readl(up->port.membase + offset); default: return inb(up->port.iobase + offset); } } static _INLINE_ void serial_out(struct uart_8250_port *up, int offset, int value) { offset <<= up->port.regshift; switch (up->port.iotype) { case UPIO_HUB6: outb(up->port.hub6 - 1 + offset, up->port.iobase); outb(value, up->port.iobase + 1); break; case UPIO_MEM: writeb(value, up->port.membase + offset); break; case UPIO_MEM32: writel(value, up->port.membase + offset); break; default: outb(value, up->port.iobase + offset); } } /* * We used to support using pause I/O for certain machines. We * haven't supported this for a while, but just in case it's badly * needed for certain old 386 machines, I've left these #define's * in.... */ #define serial_inp(up, offset) serial_in(up, offset) #define serial_outp(up, offset, value) serial_out(up, offset, value) /* * For the 16C950 */ static void serial_icr_write(struct uart_8250_port *up, int offset, int value) { serial_out(up, UART_SCR, offset); serial_out(up, UART_ICR, value); } static unsigned int serial_icr_read(struct uart_8250_port *up, int offset) { unsigned int value; serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD); serial_out(up, UART_SCR, offset); value = serial_in(up, UART_ICR); serial_icr_write(up, UART_ACR, up->acr); return value; } /* * FIFO support. */ static inline void serial8250_clear_fifos(struct uart_8250_port *p) { if (p->capabilities & UART_CAP_FIFO) { serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO); serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); serial_outp(p, UART_FCR, 0); } } /* * IER sleep support. UARTs which have EFRs need the "extended * capability" bit enabled. Note that on XR16C850s, we need to * reset LCR to write to IER. */ static inline void serial8250_set_sleep(struct uart_8250_port *p, int sleep) { if (p->capabilities & UART_CAP_SLEEP) { if (p->capabilities & UART_CAP_EFR) { serial_outp(p, UART_LCR, 0xBF); serial_outp(p, UART_EFR, UART_EFR_ECB); serial_outp(p, UART_LCR, 0); } serial_outp(p, UART_IER, sleep ? UART_IERX_SLEEP : 0); if (p->capabilities & UART_CAP_EFR) { serial_outp(p, UART_LCR, 0xBF); serial_outp(p, UART_EFR, 0); serial_outp(p, UART_LCR, 0); } } } #ifdef CONFIG_SERIAL_8250_RSA /* * Attempts to turn on the RSA FIFO. Returns zero on failure. * We set the port uart clock rate if we succeed. */ static int __enable_rsa(struct uart_8250_port *up) { unsigned char mode; int result; mode = serial_inp(up, UART_RSA_MSR); result = mode & UART_RSA_MSR_FIFO; if (!result) { serial_outp(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO); mode = serial_inp(up, UART_RSA_MSR); result = mode & UART_RSA_MSR_FIFO; } if (result) up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16; return result; } static void enable_rsa(struct uart_8250_port *up) { if (up->port.type == PORT_RSA) { if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) { spin_lock_irq(&up->port.lock); __enable_rsa(up); spin_unlock_irq(&up->port.lock); } if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) serial_outp(up, UART_RSA_FRR, 0); } } /* * Attempts to turn off the RSA FIFO. Returns zero on failure. * It is unknown why interrupts were disabled in here. However, * the caller is expected to preserve this behaviour by grabbing * the spinlock before calling this function. */ static void disable_rsa(struct uart_8250_port *up) { unsigned char mode; int result; if (up->port.type == PORT_RSA && up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) { spin_lock_irq(&up->port.lock); mode = serial_inp(up, UART_RSA_MSR); result = !(mode & UART_RSA_MSR_FIFO); if (!result) { serial_outp(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO); mode = serial_inp(up, UART_RSA_MSR); result = !(mode & UART_RSA_MSR_FIFO); } if (result) up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16; spin_unlock_irq(&up->port.lock); } } #endif /* CONFIG_SERIAL_8250_RSA */ /* * This is a quickie test to see how big the FIFO is. * It doesn't work at all the time, more's the pity. */ static int size_fifo(struct uart_8250_port *up) { unsigned char old_fcr, old_mcr, old_dll, old_dlm, old_lcr; int count; old_lcr = serial_inp(up, UART_LCR); serial_outp(up, UART_LCR, 0); old_fcr = serial_inp(up, UART_FCR); old_mcr = serial_inp(up, UART_MCR); serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); serial_outp(up, UART_MCR, UART_MCR_LOOP); serial_outp(up, UART_LCR, UART_LCR_DLAB); old_dll = serial_inp(up, UART_DLL); old_dlm = serial_inp(up, UART_DLM); serial_outp(up, UART_DLL, 0x01); serial_outp(up, UART_DLM, 0x00); serial_outp(up, UART_LCR, 0x03); for (count = 0; count < 256; count++) serial_outp(up, UART_TX, count); mdelay(20);/* FIXME - schedule_timeout */ for (count = 0; (serial_inp(up, UART_LSR) & UART_LSR_DR) && (count < 256); count++) serial_inp(up, UART_RX); serial_outp(up, UART_FCR, old_fcr); serial_outp(up, UART_MCR, old_mcr); serial_outp(up, UART_LCR, UART_LCR_DLAB); serial_outp(up, UART_DLL, old_dll); serial_outp(up, UART_DLM, old_dlm); serial_outp(up, UART_LCR, old_lcr); return count; } /* * Read UART ID using the divisor method - set DLL and DLM to zero * and the revision will be in DLL and device type in DLM. We * preserve the device state across this. */ static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p) { unsigned char old_dll, old_dlm, old_lcr; unsigned int id; old_lcr = serial_inp(p, UART_LCR); serial_outp(p, UART_LCR, UART_LCR_DLAB); old_dll = serial_inp(p, UART_DLL); old_dlm = serial_inp(p, UART_DLM); serial_outp(p, UART_DLL, 0); serial_outp(p, UART_DLM, 0); id = serial_inp(p, UART_DLL) | serial_inp(p, UART_DLM) << 8; serial_outp(p, UART_DLL, old_dll); serial_outp(p, UART_DLM, old_dlm); serial_outp(p, UART_LCR, old_lcr); return id; } /* * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's. * When this function is called we know it is at least a StarTech * 16650 V2, but it might be one of several StarTech UARTs, or one of * its clones. (We treat the broken original StarTech 16650 V1 as a * 16550, and why not? Startech doesn't seem to even acknowledge its * existence.) * * What evil have men's minds wrought... */ static void autoconfig_has_efr(struct uart_8250_port *up) { unsigned int id1, id2, id3, rev; /* * Everything with an EFR has SLEEP */ up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP; /* * First we check to see if it's an Oxford Semiconductor UART. * * If we have to do this here because some non-National * Semiconductor clone chips lock up if you try writing to the * LSR register (which serial_icr_read does) */ /* * Check for Oxford Semiconductor 16C950. * * EFR [4] must be set else this test fails. * * This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca) * claims that it's needed for 952 dual UART's (which are not * recommended for new designs). */ up->acr = 0; serial_out(up, UART_LCR, 0xBF); serial_out(up, UART_EFR, UART_EFR_ECB); serial_out(up, UART_LCR, 0x00); id1 = serial_icr_read(up, UART_ID1); id2 = serial_icr_read(up, UART_ID2); id3 = serial_icr_read(up, UART_ID3); rev = serial_icr_read(up, UART_REV); DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev); if (id1 == 0x16 && id2 == 0xC9 && (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) { up->port.type = PORT_16C950; /* * Enable work around for the Oxford Semiconductor 952 rev B * chip which causes it to seriously miscalculate baud rates * when DLL is 0. */ if (id3 == 0x52 && rev == 0x01) up->bugs |= UART_BUG_QUOT; return; } /* * We check for a XR16C850 by setting DLL and DLM to 0, and then * reading back DLL and DLM. The chip type depends on the DLM * value read back: * 0x10 - XR16C850 and the DLL contains the chip revision. * 0x12 - XR16C2850. * 0x14 - XR16C854. */ id1 = autoconfig_read_divisor_id(up); DEBUG_AUTOCONF("850id=%04x ", id1); id2 = id1 >> 8; if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) { up->port.type = PORT_16850; return; } /* * It wasn't an XR16C850. * * We distinguish between the '654 and the '650 by counting * how many bytes are in the FIFO. I'm using this for now, * since that's the technique that was sent to me in the * serial driver update, but I'm not convinced this works. * I've had problems doing this in the past. -TYT */ if (size_fifo(up) == 64) up->port.type = PORT_16654; else up->port.type = PORT_16650V2; } /* * We detected a chip without a FIFO. Only two fall into * this category - the original 8250 and the 16450. The * 16450 has a scratch register (accessible with LCR=0) */ static void autoconfig_8250(struct uart_8250_port *up) { unsigned char scratch, status1, status2; up->port.type = PORT_8250; scratch = serial_in(up, UART_SCR); serial_outp(up, UART_SCR, 0xa5); status1 = serial_in(up, UART_SCR); serial_outp(up, UART_SCR, 0x5a); status2 = serial_in(up, UART_SCR); serial_outp(up, UART_SCR, scratch); if (status1 == 0xa5 && status2 == 0x5a) up->port.type = PORT_16450; } static int broken_efr(struct uart_8250_port *up) { /* * Exar ST16C2550 "A2" devices incorrectly detect as * having an EFR, and report an ID of 0x0201. See * http://www.exar.com/info.php?pdf=dan180_oct2004.pdf */ if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16) return 1; return 0; } /* * We know that the chip has FIFOs. Does it have an EFR? The * EFR is located in the same register position as the IIR and * we know the top two bits of the IIR are currently set. The * EFR should contain zero. Try to read the EFR. */ static void autoconfig_16550a(struct uart_8250_port *up) { unsigned char status1, status2; unsigned int iersave; up->port.type = PORT_16550A; up->capabilities |= UART_CAP_FIFO; /* * Check for presence of the EFR when DLAB is set. * Only ST16C650V1 UARTs pass this test. */ serial_outp(up, UART_LCR, UART_LCR_DLAB); if (serial_in(up, UART_EFR) == 0) { serial_outp(up, UART_EFR, 0xA8); if (serial_in(up, UART_EFR) != 0) { DEBUG_AUTOCONF("EFRv1 "); up->port.type = PORT_16650; up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP; } else { DEBUG_AUTOCONF("Motorola 8xxx DUART "); } serial_outp(up, UART_EFR, 0); return; } /* * Maybe it requires 0xbf to be written to the LCR. * (other ST16C650V2 UARTs, TI16C752A, etc) */ serial_outp(up, UART_LCR, 0xBF); if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) { DEBUG_AUTOCONF("EFRv2 "); autoconfig_has_efr(up); return; } /* * Check for a National Semiconductor SuperIO chip. * Attempt to switch to bank 2, read the value of the LOOP bit * from EXCR1. Switch back to bank 0, change it in MCR. Then * switch back to bank 2, read it from EXCR1 again and check * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2 */ serial_outp(up, UART_LCR, 0); status1 = serial_in(up, UART_MCR); serial_outp(up, UART_LCR, 0xE0); status2 = serial_in(up, 0x02); /* EXCR1 */ if (!((status2 ^ status1) & UART_MCR_LOOP)) { serial_outp(up, UART_LCR, 0); serial_outp(up, UART_MCR, status1 ^ UART_MCR_LOOP); serial_outp(up, UART_LCR, 0xE0); status2 = serial_in(up, 0x02); /* EXCR1 */ serial_outp(up, UART_LCR, 0); serial_outp(up, UART_MCR, status1); if ((status2 ^ status1) & UART_MCR_LOOP) { unsigned short quot; serial_outp(up, UART_LCR, 0xE0); quot = serial_inp(up, UART_DLM) << 8; quot += serial_inp(up, UART_DLL); quot <<= 3; status1 = serial_in(up, 0x04); /* EXCR1 */ status1 &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */ status1 |= 0x10; /* 1.625 divisor for baud_base --> 921600 */ serial_outp(up, 0x04, status1); serial_outp(up, UART_DLL, quot & 0xff); serial_outp(up, UART_DLM, quot >> 8); serial_outp(up, UART_LCR, 0); up->port.uartclk = 921600*16; up->port.type = PORT_NS16550A; up->capabilities |= UART_NATSEMI; return; } } /* * No EFR. Try to detect a TI16750, which only sets bit 5 of * the IIR when 64 byte FIFO mode is enabled when DLAB is set. * Try setting it with and without DLAB set. Cheap clones * set bit 5 without DLAB set. */ serial_outp(up, UART_LCR, 0); serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE); status1 = serial_in(up, UART_IIR) >> 5; serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO); serial_outp(up, UART_LCR, UART_LCR_DLAB); serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE); status2 = serial_in(up, UART_IIR) >> 5; serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO); serial_outp(up, UART_LCR, 0); DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2); if (status1 == 6 && status2 == 7) { up->port.type = PORT_16750; up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP; return; } /* * Try writing and reading the UART_IER_UUE bit (b6). * If it works, this is probably one of the Xscale platform's * internal UARTs. * We're going to explicitly set the UUE bit to 0 before * trying to write and read a 1 just to make sure it's not * already a 1 and maybe locked there before we even start start. */ iersave = serial_in(up, UART_IER); serial_outp(up, UART_IER, iersave & ~UART_IER_UUE); if (!(serial_in(up, UART_IER) & UART_IER_UUE)) { /* * OK it's in a known zero state, try writing and reading * without disturbing the current state of the other bits. */ serial_outp(up, UART_IER, iersave | UART_IER_UUE); if (serial_in(up, UART_IER) & UART_IER_UUE) { /* * It's an Xscale. * We'll leave the UART_IER_UUE bit set to 1 (enabled). */ DEBUG_AUTOCONF("Xscale "); up->port.type = PORT_XSCALE; up->capabilities |= UART_CAP_UUE; return; } } else { /* * If we got here we couldn't force the IER_UUE bit to 0. * Log it and continue. */ DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 "); } serial_outp(up, UART_IER, iersave); } /* * This routine is called by rs_init() to initialize a specific serial * port. It determines what type of UART chip this serial port is * using: 8250, 16450, 16550, 16550A. The important question is * whether or not this UART is a 16550A or not, since this will * determine whether or not we can use its FIFO features or not. */ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags) { unsigned char status1, scratch, scratch2, scratch3; unsigned char save_lcr, save_mcr; unsigned long flags; if (!up->port.iobase && !up->port.mapbase && !up->port.membase) return; DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04x, 0x%p): ", up->port.line, up->port.iobase, up->port.membase); /* * We really do need global IRQs disabled here - we're going to * be frobbing the chips IRQ enable register to see if it exists. */ spin_lock_irqsave(&up->port.lock, flags); // save_flags(flags); cli(); up->capabilities = 0; up->bugs = 0; if (!(up->port.flags & UPF_BUGGY_UART)) { /* * Do a simple existence test first; if we fail this, * there's no point trying anything else. * * 0x80 is used as a nonsense port to prevent against * false positives due to ISA bus float. The * assumption is that 0x80 is a non-existent port; * which should be safe since include/asm/io.h also * makes this assumption. * * Note: this is safe as long as MCR bit 4 is clear * and the device is in "PC" mode. */ scratch = serial_inp(up, UART_IER); serial_outp(up, UART_IER, 0); #ifdef __i386__ outb(0xff, 0x080); #endif scratch2 = serial_inp(up, UART_IER); serial_outp(up, UART_IER, 0x0F); #ifdef __i386__ outb(0, 0x080); #endif scratch3 = serial_inp(up, UART_IER); serial_outp(up, UART_IER, scratch); if (scratch2 != 0 || scratch3 != 0x0F) { /* * We failed; there's nothing here */ DEBUG_AUTOCONF("IER test failed (%02x, %02x) ", scratch2, scratch3); goto out; } } save_mcr = serial_in(up, UART_MCR); save_lcr = serial_in(up, UART_LCR); /* * Check to see if a UART is really there. Certain broken * internal modems based on the Rockwell chipset fail this * test, because they apparently don't implement the loopback * test mode. So this test is skipped on the COM 1 through * COM 4 ports. This *should* be safe, since no board * manufacturer would be stupid enough to design a board * that conflicts with COM 1-4 --- we hope! */ if (!(up->port.flags & UPF_SKIP_TEST)) { serial_outp(up, UART_MCR, UART_MCR_LOOP | 0x0A); status1 = serial_inp(up, UART_MSR) & 0xF0; serial_outp(up, UART_MCR, save_mcr); if (status1 != 0x90) { DEBUG_AUTOCONF("LOOP test failed (%02x) ", status1); goto out; } } /* * We're pretty sure there's a port here. Lets find out what * type of port it is. The IIR top two bits allows us to find * out if its 8250 or 16450, 16550, 16550A or later. This * determines what we test for next. * * We also initialise the EFR (if any) to zero for later. The * EFR occupies the same register location as the FCR and IIR. */ serial_outp(up, UART_LCR, 0xBF); serial_outp(up, UART_EFR, 0); serial_outp(up, UART_LCR, 0); serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO); scratch = serial_in(up, UART_IIR) >> 6; DEBUG_AUTOCONF("iir=%d ", scratch); switch (scratch) { case 0: autoconfig_8250(up); break; case 1: up->port.type = PORT_UNKNOWN; break; case 2: up->port.type = PORT_16550; break; case 3: autoconfig_16550a(up); break; } #ifdef CONFIG_SERIAL_8250_RSA /* * Only probe for RSA ports if we got the region. */ if (up->port.type == PORT_16550A && probeflags & PROBE_RSA) { int i; for (i = 0 ; i < probe_rsa_count; ++i) { if (probe_rsa[i] == up->port.iobase && __enable_rsa(up)) { up->port.type = PORT_RSA; break; } } } #endif serial_outp(up, UART_LCR, save_lcr); if (up->capabilities != uart_config[up->port.type].flags) { printk(KERN_WARNING "ttyS%d: detected caps %08x should be %08x\n", up->port.line, up->capabilities, uart_config[up->port.type].flags); } up->port.fifosize = uart_config[up->port.type].fifo_size; up->capabilities = uart_config[up->port.type].flags; up->tx_loadsz = uart_config[up->port.type].tx_loadsz; if (up->port.type == PORT_UNKNOWN) goto out; /* * Reset the UART. */ #ifdef CONFIG_SERIAL_8250_RSA if (up->port.type == PORT_RSA) serial_outp(up, UART_RSA_FRR, 0); #endif serial_outp(up, UART_MCR, save_mcr); serial8250_clear_fifos(up); (void)serial_in(up, UART_RX); serial_outp(up, UART_IER, 0); out: spin_unlock_irqrestore(&up->port.lock, flags); // restore_flags(flags); DEBUG_AUTOCONF("type=%s\n", uart_config[up->port.type].name); } static void autoconfig_irq(struct uart_8250_port *up) { unsigned char save_mcr, save_ier; unsigned char save_ICP = 0; unsigned int ICP = 0; unsigned long irqs; int irq; if (up->port.flags & UPF_FOURPORT) { ICP = (up->port.iobase & 0xfe0) | 0x1f; save_ICP = inb_p(ICP); outb_p(0x80, ICP); (void) inb_p(ICP); } /* forget possible initially masked and pending IRQ */ probe_irq_off(probe_irq_on()); save_mcr = serial_inp(up, UART_MCR); save_ier = serial_inp(up, UART_IER); serial_outp(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2); irqs = probe_irq_on(); serial_outp(up, UART_MCR, 0); udelay (10); if (up->port.flags & UPF_FOURPORT) { serial_outp(up, UART_MCR, UART_MCR_DTR | UART_MCR_RTS); } else { serial_outp(up, UART_MCR, UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2); } serial_outp(up, UART_IER, 0x0f); /* enable all intrs */ (void)serial_inp(up, UART_LSR); (void)serial_inp(up, UART_RX); (void)serial_inp(up, UART_IIR); (void)serial_inp(up, UART_MSR); serial_outp(up, UART_TX, 0xFF); udelay (20); irq = probe_irq_off(irqs); serial_outp(up, UART_MCR, save_mcr); serial_outp(up, UART_IER, save_ier); if (up->port.flags & UPF_FOURPORT) outb_p(save_ICP, ICP); up->port.irq = (irq > 0) ? irq : 0; } static inline void __stop_tx(struct uart_8250_port *p) { if (p->ier & UART_IER_THRI) { p->ier &= ~UART_IER_THRI; serial_out(p, UART_IER, p->ier); } } static void serial8250_stop_tx(struct uart_port *port, unsigned int tty_stop) { struct uart_8250_port *up = (struct uart_8250_port *)port; __stop_tx(up); /* * We really want to stop the transmitter from sending. */ if (up->port.type == PORT_16C950) { up->acr |= UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } } static void transmit_chars(struct uart_8250_port *up); static void serial8250_start_tx(struct uart_port *port, unsigned int tty_start) { struct uart_8250_port *up = (struct uart_8250_port *)port; if (!(up->ier & UART_IER_THRI)) { up->ier |= UART_IER_THRI; serial_out(up, UART_IER, up->ier); if (up->bugs & UART_BUG_TXEN) { unsigned char lsr, iir; lsr = serial_in(up, UART_LSR); iir = serial_in(up, UART_IIR); if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) transmit_chars(up); } } /* * Re-enable the transmitter if we disabled it. */ if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) { up->acr &= ~UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } } static void serial8250_stop_rx(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; up->ier &= ~UART_IER_RLSI; up->port.read_status_mask &= ~UART_LSR_DR; serial_out(up, UART_IER, up->ier); } static void serial8250_enable_ms(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; up->ier |= UART_IER_MSI; serial_out(up, UART_IER, up->ier); } static _INLINE_ void receive_chars(struct uart_8250_port *up, int *status, struct pt_regs *regs) { struct tty_struct *tty = up->port.info->tty; unsigned char ch, lsr = *status; int max_count = 256; char flag; do { /* The following is not allowed by the tty layer and unsafe. It should be fixed ASAP */ if (unlikely(tty->flip.count >= TTY_FLIPBUF_SIZE)) { if (tty->low_latency) { spin_unlock(&up->port.lock); tty_flip_buffer_push(tty); spin_lock(&up->port.lock); } /* * If this failed then we will throw away the * bytes but must do so to clear interrupts */ } ch = serial_inp(up, UART_RX); flag = TTY_NORMAL; up->port.icount.rx++; #ifdef CONFIG_SERIAL_8250_CONSOLE /* * Recover the break flag from console xmit */ if (up->port.line == up->port.cons->index) { lsr |= up->lsr_break_flag; up->lsr_break_flag = 0; } #endif if (unlikely(lsr & (UART_LSR_BI | UART_LSR_PE | UART_LSR_FE | UART_LSR_OE))) { /* * For statistics only */ if (lsr & UART_LSR_BI) { lsr &= ~(UART_LSR_FE | UART_LSR_PE); up->port.icount.brk++; /* * We do the SysRQ and SAK checking * here because otherwise the break * may get masked by ignore_status_mask * or read_status_mask. */ if (uart_handle_break(&up->port)) goto ignore_char; } else if (lsr & UART_LSR_PE) up->port.icount.parity++; else if (lsr & UART_LSR_FE) up->port.icount.frame++; if (lsr & UART_LSR_OE) up->port.icount.overrun++; /* * Mask off conditions which should be ignored. */ lsr &= up->port.read_status_mask; if (lsr & UART_LSR_BI) { DEBUG_INTR("handling break...."); flag = TTY_BREAK; } else if (lsr & UART_LSR_PE) flag = TTY_PARITY; else if (lsr & UART_LSR_FE) flag = TTY_FRAME; } if (uart_handle_sysrq_char(&up->port, ch, regs)) goto ignore_char; uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag); ignore_char: lsr = serial_inp(up, UART_LSR); } while ((lsr & UART_LSR_DR) && (max_count-- > 0)); spin_unlock(&up->port.lock); tty_flip_buffer_push(tty); spin_lock(&up->port.lock); *status = lsr; } static _INLINE_ void transmit_chars(struct uart_8250_port *up) { struct circ_buf *xmit = &up->port.info->xmit; int count; if (up->port.x_char) { serial_outp(up, UART_TX, up->port.x_char); up->port.icount.tx++; up->port.x_char = 0; return; } if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) { __stop_tx(up); return; } count = up->tx_loadsz; do { serial_out(up, UART_TX, xmit->buf[xmit->tail]); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); up->port.icount.tx++; if (uart_circ_empty(xmit)) break; } while (--count > 0); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&up->port); DEBUG_INTR("THRE..."); if (uart_circ_empty(xmit)) __stop_tx(up); } static _INLINE_ void check_modem_status(struct uart_8250_port *up) { int status; status = serial_in(up, UART_MSR); if ((status & UART_MSR_ANY_DELTA) == 0) return; if (status & UART_MSR_TERI) up->port.icount.rng++; if (status & UART_MSR_DDSR) up->port.icount.dsr++; if (status & UART_MSR_DDCD) uart_handle_dcd_change(&up->port, status & UART_MSR_DCD); if (status & UART_MSR_DCTS) uart_handle_cts_change(&up->port, status & UART_MSR_CTS); wake_up_interruptible(&up->port.info->delta_msr_wait); } /* * This handles the interrupt from one port. */ static inline void serial8250_handle_port(struct uart_8250_port *up, struct pt_regs *regs) { unsigned int status = serial_inp(up, UART_LSR); DEBUG_INTR("status = %x...", status); if (status & UART_LSR_DR) receive_chars(up, &status, regs); check_modem_status(up); if (status & UART_LSR_THRE) transmit_chars(up); } /* * This is the serial driver's interrupt routine. * * Arjan thinks the old way was overly complex, so it got simplified. * Alan disagrees, saying that need the complexity to handle the weird * nature of ISA shared interrupts. (This is a special exception.) * * In order to handle ISA shared interrupts properly, we need to check * that all ports have been serviced, and therefore the ISA interrupt * line has been de-asserted. * * This means we need to loop through all ports. checking that they * don't have an interrupt pending. */ static irqreturn_t serial8250_interrupt(int irq, void *dev_id, struct pt_regs *regs) { struct irq_info *i = dev_id; struct list_head *l, *end = NULL; int pass_counter = 0, handled = 0; DEBUG_INTR("serial8250_interrupt(%d)...", irq); spin_lock(&i->lock); l = i->head; do { struct uart_8250_port *up; unsigned int iir; up = list_entry(l, struct uart_8250_port, list); iir = serial_in(up, UART_IIR); if (!(iir & UART_IIR_NO_INT)) { spin_lock(&up->port.lock); serial8250_handle_port(up, regs); spin_unlock(&up->port.lock); handled = 1; end = NULL; } else if (end == NULL) end = l; l = l->next; if (l == i->head && pass_counter++ > PASS_LIMIT) { /* If we hit this, we're dead. */ printk(KERN_ERR "serial8250: too much work for " "irq%d\n", irq); break; } } while (l != end); spin_unlock(&i->lock); DEBUG_INTR("end.\n"); return IRQ_RETVAL(handled); } /* * To support ISA shared interrupts, we need to have one interrupt * handler that ensures that the IRQ line has been deasserted * before returning. Failing to do this will result in the IRQ * line being stuck active, and, since ISA irqs are edge triggered, * no more IRQs will be seen. */ static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up) { spin_lock_irq(&i->lock); if (!list_empty(i->head)) { if (i->head == &up->list) i->head = i->head->next; list_del(&up->list); } else { BUG_ON(i->head != &up->list); i->head = NULL; } spin_unlock_irq(&i->lock); } static int serial_link_irq_chain(struct uart_8250_port *up) { struct irq_info *i = irq_lists + up->port.irq; int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? SA_SHIRQ : 0; spin_lock_irq(&i->lock); if (i->head) { list_add(&up->list, i->head); spin_unlock_irq(&i->lock); ret = 0; } else { INIT_LIST_HEAD(&up->list); i->head = &up->list; spin_unlock_irq(&i->lock); ret = request_irq(up->port.irq, serial8250_interrupt, irq_flags, "serial", i); if (ret < 0) serial_do_unlink(i, up); } return ret; } static void serial_unlink_irq_chain(struct uart_8250_port *up) { struct irq_info *i = irq_lists + up->port.irq; BUG_ON(i->head == NULL); if (list_empty(i->head)) free_irq(up->port.irq, i); serial_do_unlink(i, up); } /* * This function is used to handle ports that do not have an * interrupt. This doesn't work very well for 16450's, but gives * barely passable results for a 16550A. (Although at the expense * of much CPU overhead). */ static void serial8250_timeout(unsigned long data) { struct uart_8250_port *up = (struct uart_8250_port *)data; unsigned int timeout; unsigned int iir; iir = serial_in(up, UART_IIR); if (!(iir & UART_IIR_NO_INT)) { spin_lock(&up->port.lock); serial8250_handle_port(up, NULL); spin_unlock(&up->port.lock); } timeout = up->port.timeout; timeout = timeout > 6 ? (timeout / 2 - 2) : 1; mod_timer(&up->timer, jiffies + timeout); } static unsigned int serial8250_tx_empty(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; unsigned long flags; unsigned int ret; spin_lock_irqsave(&up->port.lock, flags); ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0; spin_unlock_irqrestore(&up->port.lock, flags); return ret; } static unsigned int serial8250_get_mctrl(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; unsigned char status; unsigned int ret; status = serial_in(up, UART_MSR); ret = 0; if (status & UART_MSR_DCD) ret |= TIOCM_CAR; if (status & UART_MSR_RI) ret |= TIOCM_RNG; if (status & UART_MSR_DSR) ret |= TIOCM_DSR; if (status & UART_MSR_CTS) ret |= TIOCM_CTS; return ret; } static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct uart_8250_port *up = (struct uart_8250_port *)port; unsigned char mcr = 0; if (mctrl & TIOCM_RTS) mcr |= UART_MCR_RTS; if (mctrl & TIOCM_DTR) mcr |= UART_MCR_DTR; if (mctrl & TIOCM_OUT1) mcr |= UART_MCR_OUT1; if (mctrl & TIOCM_OUT2) mcr |= UART_MCR_OUT2; if (mctrl & TIOCM_LOOP) mcr |= UART_MCR_LOOP; mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr; serial_out(up, UART_MCR, mcr); } static void serial8250_break_ctl(struct uart_port *port, int break_state) { struct uart_8250_port *up = (struct uart_8250_port *)port; unsigned long flags; spin_lock_irqsave(&up->port.lock, flags); if (break_state == -1) up->lcr |= UART_LCR_SBC; else up->lcr &= ~UART_LCR_SBC; serial_out(up, UART_LCR, up->lcr); spin_unlock_irqrestore(&up->port.lock, flags); } static int serial8250_startup(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; unsigned long flags; unsigned char lsr, iir; int retval; up->capabilities = uart_config[up->port.type].flags; up->mcr = 0; if (up->port.type == PORT_16C950) { /* Wake up and initialize UART */ up->acr = 0; serial_outp(up, UART_LCR, 0xBF); serial_outp(up, UART_EFR, UART_EFR_ECB); serial_outp(up, UART_IER, 0); serial_outp(up, UART_LCR, 0); serial_icr_write(up, UART_CSR, 0); /* Reset the UART */ serial_outp(up, UART_LCR, 0xBF); serial_outp(up, UART_EFR, UART_EFR_ECB); serial_outp(up, UART_LCR, 0); } #ifdef CONFIG_SERIAL_8250_RSA /* * If this is an RSA port, see if we can kick it up to the * higher speed clock. */ enable_rsa(up); #endif /* * Clear the FIFO buffers and disable them. * (they will be reeanbled in set_termios()) */ serial8250_clear_fifos(up); /* * Clear the interrupt registers. */ (void) serial_inp(up, UART_LSR); (void) serial_inp(up, UART_RX); (void) serial_inp(up, UART_IIR); (void) serial_inp(up, UART_MSR); /* * At this point, there's no way the LSR could still be 0xff; * if it is, then bail out, because there's likely no UART * here. */ if (!(up->port.flags & UPF_BUGGY_UART) && (serial_inp(up, UART_LSR) == 0xff)) { printk("ttyS%d: LSR safety check engaged!\n", up->port.line); return -ENODEV; } /* * For a XR16C850, we need to set the trigger levels */ if (up->port.type == PORT_16850) { unsigned char fctr; serial_outp(up, UART_LCR, 0xbf); fctr = serial_inp(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX); serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_RX); serial_outp(up, UART_TRG, UART_TRG_96); serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_TX); serial_outp(up, UART_TRG, UART_TRG_96); serial_outp(up, UART_LCR, 0); } /* * If the "interrupt" for this port doesn't correspond with any * hardware interrupt, we use a timer-based system. The original * driver used to do this with IRQ0. */ if (!is_real_interrupt(up->port.irq)) { unsigned int timeout = up->port.timeout; timeout = timeout > 6 ? (timeout / 2 - 2) : 1; up->timer.data = (unsigned long)up; mod_timer(&up->timer, jiffies + timeout); } else { retval = serial_link_irq_chain(up); if (retval) return retval; } /* * Now, initialize the UART */ serial_outp(up, UART_LCR, UART_LCR_WLEN8); spin_lock_irqsave(&up->port.lock, flags); if (up->port.flags & UPF_FOURPORT) { if (!is_real_interrupt(up->port.irq)) up->port.mctrl |= TIOCM_OUT1; } else /* * Most PC uarts need OUT2 raised to enable interrupts. */ if (is_real_interrupt(up->port.irq)) up->port.mctrl |= TIOCM_OUT2; serial8250_set_mctrl(&up->port, up->port.mctrl); /* * Do a quick test to see if we receive an * interrupt when we enable the TX irq. */ serial_outp(up, UART_IER, UART_IER_THRI); lsr = serial_in(up, UART_LSR); iir = serial_in(up, UART_IIR); serial_outp(up, UART_IER, 0); if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) { if (!(up->bugs & UART_BUG_TXEN)) { up->bugs |= UART_BUG_TXEN; pr_debug("ttyS%d - enabling bad tx status workarounds\n", port->line); } } else { up->bugs &= ~UART_BUG_TXEN; } spin_unlock_irqrestore(&up->port.lock, flags); /* * Finally, enable interrupts. Note: Modem status interrupts * are set via set_termios(), which will be occurring imminently * anyway, so we don't enable them here. */ up->ier = UART_IER_RLSI | UART_IER_RDI; serial_outp(up, UART_IER, up->ier); if (up->port.flags & UPF_FOURPORT) { unsigned int icp; /* * Enable interrupts on the AST Fourport board */ icp = (up->port.iobase & 0xfe0) | 0x01f; outb_p(0x80, icp); (void) inb_p(icp); } /* * And clear the interrupt registers again for luck. */ (void) serial_inp(up, UART_LSR); (void) serial_inp(up, UART_RX); (void) serial_inp(up, UART_IIR); (void) serial_inp(up, UART_MSR); return 0; } static void serial8250_shutdown(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; unsigned long flags; /* * Disable interrupts from this port */ up->ier = 0; serial_outp(up, UART_IER, 0); spin_lock_irqsave(&up->port.lock, flags); if (up->port.flags & UPF_FOURPORT) { /* reset interrupts on the AST Fourport board */ inb((up->port.iobase & 0xfe0) | 0x1f); up->port.mctrl |= TIOCM_OUT1; } else up->port.mctrl &= ~TIOCM_OUT2; serial8250_set_mctrl(&up->port, up->port.mctrl); spin_unlock_irqrestore(&up->port.lock, flags); /* * Disable break condition and FIFOs */ serial_out(up, UART_LCR, serial_inp(up, UART_LCR) & ~UART_LCR_SBC); serial8250_clear_fifos(up); #ifdef CONFIG_SERIAL_8250_RSA /* * Reset the RSA board back to 115kbps compat mode. */ disable_rsa(up); #endif /* * Read data port to reset things, and then unlink from * the IRQ chain. */ (void) serial_in(up, UART_RX); if (!is_real_interrupt(up->port.irq)) del_timer_sync(&up->timer); else serial_unlink_irq_chain(up); } static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud) { unsigned int quot; /* * Handle magic divisors for baud rates above baud_base on * SMSC SuperIO chips. */ if ((port->flags & UPF_MAGIC_MULTIPLIER) && baud == (port->uartclk/4)) quot = 0x8001; else if ((port->flags & UPF_MAGIC_MULTIPLIER) && baud == (port->uartclk/8)) quot = 0x8002; else quot = uart_get_divisor(port, baud); return quot; } static void serial8250_set_termios(struct uart_port *port, struct termios *termios, struct termios *old) { struct uart_8250_port *up = (struct uart_8250_port *)port; unsigned char cval, fcr = 0; unsigned long flags; unsigned int baud, quot; switch (termios->c_cflag & CSIZE) { case CS5: cval = UART_LCR_WLEN5; break; case CS6: cval = UART_LCR_WLEN6; break; case CS7: cval = UART_LCR_WLEN7; break; default: case CS8: cval = UART_LCR_WLEN8; break; } if (termios->c_cflag & CSTOPB) cval |= UART_LCR_STOP; if (termios->c_cflag & PARENB) cval |= UART_LCR_PARITY; if (!(termios->c_cflag & PARODD)) cval |= UART_LCR_EPAR; #ifdef CMSPAR if (termios->c_cflag & CMSPAR) cval |= UART_LCR_SPAR; #endif /* * Ask the core to calculate the divisor for us. */ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); quot = serial8250_get_divisor(port, baud); /* * Oxford Semi 952 rev B workaround */ if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0) quot ++; if (up->capabilities & UART_CAP_FIFO && up->port.fifosize > 1) { if (baud < 2400) fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1; else fcr = uart_config[up->port.type].fcr; } /* * MCR-based auto flow control. When AFE is enabled, RTS will be * deasserted when the receive FIFO contains more characters than * the trigger, or the MCR RTS bit is cleared. In the case where * the remote UART is not using CTS auto flow control, we must * have sufficient FIFO entries for the latency of the remote * UART to respond. IOW, at least 32 bytes of FIFO. */ if (up->capabilities & UART_CAP_AFE && up->port.fifosize >= 32) { up->mcr &= ~UART_MCR_AFE; if (termios->c_cflag & CRTSCTS) up->mcr |= UART_MCR_AFE; } /* * Ok, we're now changing the port state. Do it with * interrupts disabled. */ spin_lock_irqsave(&up->port.lock, flags); /* * Update the per-port timeout. */ uart_update_timeout(port, termios->c_cflag, baud); up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR; if (termios->c_iflag & INPCK) up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE; if (termios->c_iflag & (BRKINT | PARMRK)) up->port.read_status_mask |= UART_LSR_BI; /* * Characteres to ignore */ up->port.ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE; if (termios->c_iflag & IGNBRK) { up->port.ignore_status_mask |= UART_LSR_BI; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) up->port.ignore_status_mask |= UART_LSR_OE; } /* * ignore all characters if CREAD is not set */ if ((termios->c_cflag & CREAD) == 0) up->port.ignore_status_mask |= UART_LSR_DR; /* * CTS flow control flag and modem status interrupts */ up->ier &= ~UART_IER_MSI; if (UART_ENABLE_MS(&up->port, termios->c_cflag)) up->ier |= UART_IER_MSI; if (up->capabilities & UART_CAP_UUE) up->ier |= UART_IER_UUE | UART_IER_RTOIE; serial_out(up, UART_IER, up->ier); if (up->capabilities & UART_CAP_EFR) { unsigned char efr = 0; /* * TI16C752/Startech hardware flow control. FIXME: * - TI16C752 requires control thresholds to be set. * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled. */ if (termios->c_cflag & CRTSCTS) efr |= UART_EFR_CTS; serial_outp(up, UART_LCR, 0xBF); serial_outp(up, UART_EFR, efr); } if (up->capabilities & UART_NATSEMI) { /* Switch to bank 2 not bank 1, to avoid resetting EXCR2 */ serial_outp(up, UART_LCR, 0xe0); } else { serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */ } serial_outp(up, UART_DLL, quot & 0xff); /* LS of divisor */ serial_outp(up, UART_DLM, quot >> 8); /* MS of divisor */ /* * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR * is written without DLAB set, this mode will be disabled. */ if (up->port.type == PORT_16750) serial_outp(up, UART_FCR, fcr); serial_outp(up, UART_LCR, cval); /* reset DLAB */ up->lcr = cval; /* Save LCR */ if (up->port.type != PORT_16750) { if (fcr & UART_FCR_ENABLE_FIFO) { /* emulated UARTs (Lucent Venus 167x) need two steps */ serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO); } serial_outp(up, UART_FCR, fcr); /* set fcr */ } serial8250_set_mctrl(&up->port, up->port.mctrl); spin_unlock_irqrestore(&up->port.lock, flags); } static void serial8250_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { struct uart_8250_port *p = (struct uart_8250_port *)port; serial8250_set_sleep(p, state != 0); if (p->pm) p->pm(port, state, oldstate); } /* * Resource handling. */ static int serial8250_request_std_resource(struct uart_8250_port *up) { unsigned int size = 8 << up->port.regshift; int ret = 0; switch (up->port.iotype) { case UPIO_MEM: if (!up->port.mapbase) break; if (!request_mem_region(up->port.mapbase, size, "serial")) { ret = -EBUSY; break; } if (up->port.flags & UPF_IOREMAP) { up->port.membase = ioremap(up->port.mapbase, size); if (!up->port.membase) { release_mem_region(up->port.mapbase, size); ret = -ENOMEM; } } break; case UPIO_HUB6: case UPIO_PORT: if (!request_region(up->port.iobase, size, "serial")) ret = -EBUSY; break; } return ret; } static void serial8250_release_std_resource(struct uart_8250_port *up) { unsigned int size = 8 << up->port.regshift; switch (up->port.iotype) { case UPIO_MEM: if (!up->port.mapbase) break; if (up->port.flags & UPF_IOREMAP) { iounmap(up->port.membase); up->port.membase = NULL; } release_mem_region(up->port.mapbase, size); break; case UPIO_HUB6: case UPIO_PORT: release_region(up->port.iobase, size); break; } } static int serial8250_request_rsa_resource(struct uart_8250_port *up) { unsigned long start = UART_RSA_BASE << up->port.regshift; unsigned int size = 8 << up->port.regshift; int ret = 0; switch (up->port.iotype) { case UPIO_MEM: ret = -EINVAL; break; case UPIO_HUB6: case UPIO_PORT: start += up->port.iobase; if (!request_region(start, size, "serial-rsa")) ret = -EBUSY; break; } return ret; } static void serial8250_release_rsa_resource(struct uart_8250_port *up) { unsigned long offset = UART_RSA_BASE << up->port.regshift; unsigned int size = 8 << up->port.regshift; switch (up->port.iotype) { case UPIO_MEM: break; case UPIO_HUB6: case UPIO_PORT: release_region(up->port.iobase + offset, size); break; } } static void serial8250_release_port(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; serial8250_release_std_resource(up); if (up->port.type == PORT_RSA) serial8250_release_rsa_resource(up); } static int serial8250_request_port(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; int ret = 0; ret = serial8250_request_std_resource(up); if (ret == 0 && up->port.type == PORT_RSA) { ret = serial8250_request_rsa_resource(up); if (ret < 0) serial8250_release_std_resource(up); } return ret; } static void serial8250_config_port(struct uart_port *port, int flags) { struct uart_8250_port *up = (struct uart_8250_port *)port; int probeflags = PROBE_ANY; int ret; /* * Don't probe for MCA ports on non-MCA machines. */ if (up->port.flags & UPF_BOOT_ONLYMCA && !MCA_bus) return; /* * Find the region that we can probe for. This in turn * tells us whether we can probe for the type of port. */ ret = serial8250_request_std_resource(up); if (ret < 0) return; ret = serial8250_request_rsa_resource(up); if (ret < 0) probeflags &= ~PROBE_RSA; if (flags & UART_CONFIG_TYPE) autoconfig(up, probeflags); if (up->port.type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ) autoconfig_irq(up); if (up->port.type != PORT_RSA && probeflags & PROBE_RSA) serial8250_release_rsa_resource(up); if (up->port.type == PORT_UNKNOWN) serial8250_release_std_resource(up); } static int serial8250_verify_port(struct uart_port *port, struct serial_struct *ser) { if (ser->irq >= NR_IRQS || ser->irq < 0 || ser->baud_base < 9600 || ser->type < PORT_UNKNOWN || ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS || ser->type == PORT_STARTECH) return -EINVAL; return 0; } static const char * serial8250_type(struct uart_port *port) { int type = port->type; if (type >= ARRAY_SIZE(uart_config)) type = 0; return uart_config[type].name; } static struct uart_ops serial8250_pops = { .tx_empty = serial8250_tx_empty, .set_mctrl = serial8250_set_mctrl, .get_mctrl = serial8250_get_mctrl, .stop_tx = serial8250_stop_tx, .start_tx = serial8250_start_tx, .stop_rx = serial8250_stop_rx, .enable_ms = serial8250_enable_ms, .break_ctl = serial8250_break_ctl, .startup = serial8250_startup, .shutdown = serial8250_shutdown, .set_termios = serial8250_set_termios, .pm = serial8250_pm, .type = serial8250_type, .release_port = serial8250_release_port, .request_port = serial8250_request_port, .config_port = serial8250_config_port, .verify_port = serial8250_verify_port, }; static struct uart_8250_port serial8250_ports[UART_NR]; static void __init serial8250_isa_init_ports(void) { struct uart_8250_port *up; static int first = 1; int i; if (!first) return; first = 0; for (i = 0; i < UART_NR; i++) { struct uart_8250_port *up = &serial8250_ports[i]; up->port.line = i; spin_lock_init(&up->port.lock); init_timer(&up->timer); up->timer.function = serial8250_timeout; /* * ALPHA_KLUDGE_MCR needs to be killed. */ up->mcr_mask = ~ALPHA_KLUDGE_MCR; up->mcr_force = ALPHA_KLUDGE_MCR; up->port.ops = &serial8250_pops; } for (i = 0, up = serial8250_ports; i < ARRAY_SIZE(old_serial_port) && i < UART_NR; i++, up++) { up->port.iobase = old_serial_port[i].port; up->port.irq = irq_canonicalize(old_serial_port[i].irq); up->port.uartclk = old_serial_port[i].baud_base * 16; up->port.flags = old_serial_port[i].flags; up->port.hub6 = old_serial_port[i].hub6; up->port.membase = old_serial_port[i].iomem_base; up->port.iotype = old_serial_port[i].io_type; up->port.regshift = old_serial_port[i].iomem_reg_shift; if (share_irqs) up->port.flags |= UPF_SHARE_IRQ; } } static void __init serial8250_register_ports(struct uart_driver *drv, struct device *dev) { int i; serial8250_isa_init_ports(); for (i = 0; i < UART_NR; i++) { struct uart_8250_port *up = &serial8250_ports[i]; up->port.dev = dev; uart_add_one_port(drv, &up->port); } } #ifdef CONFIG_SERIAL_8250_CONSOLE #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) /* * Wait for transmitter & holding register to empty */ static inline void wait_for_xmitr(struct uart_8250_port *up) { unsigned int status, tmout = 10000; /* Wait up to 10ms for the character(s) to be sent. */ do { status = serial_in(up, UART_LSR); if (status & UART_LSR_BI) up->lsr_break_flag = UART_LSR_BI; if (--tmout == 0) break; udelay(1); } while ((status & BOTH_EMPTY) != BOTH_EMPTY); /* Wait up to 1s for flow control if necessary */ if (up->port.flags & UPF_CONS_FLOW) { tmout = 1000000; while (--tmout && ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0)) udelay(1); } } /* * Print a string to the serial port trying not to disturb * any possible real use of the port... * * The console_lock must be held when we get here. */ static void serial8250_console_write(struct console *co, const char *s, unsigned int count) { struct uart_8250_port *up = &serial8250_ports[co->index]; unsigned int ier; int i; /* * First save the UER then disable the interrupts */ ier = serial_in(up, UART_IER); if (up->capabilities & UART_CAP_UUE) serial_out(up, UART_IER, UART_IER_UUE); else serial_out(up, UART_IER, 0); /* * Now, do each character */ for (i = 0; i < count; i++, s++) { wait_for_xmitr(up); /* * Send the character out. * If a LF, also do CR... */ serial_out(up, UART_TX, *s); if (*s == 10) { wait_for_xmitr(up); serial_out(up, UART_TX, 13); } } /* * Finally, wait for transmitter to become empty * and restore the IER */ wait_for_xmitr(up); serial_out(up, UART_IER, ier); } static int serial8250_console_setup(struct console *co, char *options) { struct uart_port *port; int baud = 9600; int bits = 8; int parity = 'n'; int flow = 'n'; /* * Check whether an invalid uart number has been specified, and * if so, search for the first available port that does have * console support. */ if (co->index >= UART_NR) co->index = 0; port = &serial8250_ports[co->index].port; if (!port->iobase && !port->membase) return -ENODEV; if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); return uart_set_options(port, co, baud, parity, bits, flow); } static struct uart_driver serial8250_reg; static struct console serial8250_console = { .name = "ttyS", .write = serial8250_console_write, .device = uart_console_device, .setup = serial8250_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &serial8250_reg, }; static int __init serial8250_console_init(void) { serial8250_isa_init_ports(); register_console(&serial8250_console); return 0; } console_initcall(serial8250_console_init); static int __init find_port(struct uart_port *p) { int line; struct uart_port *port; for (line = 0; line < UART_NR; line++) { port = &serial8250_ports[line].port; if (p->iotype == port->iotype && p->iobase == port->iobase && p->membase == port->membase) return line; } return -ENODEV; } int __init serial8250_start_console(struct uart_port *port, char *options) { int line; line = find_port(port); if (line < 0) return -ENODEV; add_preferred_console("ttyS", line, options); printk("Adding console on ttyS%d at %s 0x%lx (options '%s')\n", line, port->iotype == UPIO_MEM ? "MMIO" : "I/O port", port->iotype == UPIO_MEM ? (unsigned long) port->mapbase : (unsigned long) port->iobase, options); if (!(serial8250_console.flags & CON_ENABLED)) { serial8250_console.flags &= ~CON_PRINTBUFFER; register_console(&serial8250_console); } return line; } #define SERIAL8250_CONSOLE &serial8250_console #else #define SERIAL8250_CONSOLE NULL #endif static struct uart_driver serial8250_reg = { .owner = THIS_MODULE, .driver_name = "serial", .devfs_name = "tts/", .dev_name = "ttyS", .major = TTY_MAJOR, .minor = 64, .nr = UART_NR, .cons = SERIAL8250_CONSOLE, }; int __init early_serial_setup(struct uart_port *port) { if (port->line >= ARRAY_SIZE(serial8250_ports)) return -ENODEV; serial8250_isa_init_ports(); serial8250_ports[port->line].port = *port; serial8250_ports[port->line].port.ops = &serial8250_pops; return 0; } /** * serial8250_suspend_port - suspend one serial port * @line: serial line number * @level: the level of port suspension, as per uart_suspend_port * * Suspend one serial port. */ void serial8250_suspend_port(int line) { uart_suspend_port(&serial8250_reg, &serial8250_ports[line].port); } /** * serial8250_resume_port - resume one serial port * @line: serial line number * @level: the level of port resumption, as per uart_resume_port * * Resume one serial port. */ void serial8250_resume_port(int line) { uart_resume_port(&serial8250_reg, &serial8250_ports[line].port); } /* * Register a set of serial devices attached to a platform device. The * list is terminated with a zero flags entry, which means we expect * all entries to have at least UPF_BOOT_AUTOCONF set. */ static int __devinit serial8250_probe(struct device *dev) { struct plat_serial8250_port *p = dev->platform_data; struct uart_port port; int ret, i; memset(&port, 0, sizeof(struct uart_port)); for (i = 0; p && p->flags != 0; p++, i++) { port.iobase = p->iobase; port.membase = p->membase; port.irq = p->irq; port.uartclk = p->uartclk; port.regshift = p->regshift; port.iotype = p->iotype; port.flags = p->flags; port.mapbase = p->mapbase; port.hub6 = p->hub6; port.dev = dev; if (share_irqs) port.flags |= UPF_SHARE_IRQ; ret = serial8250_register_port(&port); if (ret < 0) { dev_err(dev, "unable to register port at index %d " "(IO%lx MEM%lx IRQ%d): %d\n", i, p->iobase, p->mapbase, p->irq, ret); } } return 0; } /* * Remove serial ports registered against a platform device. */ static int __devexit serial8250_remove(struct device *dev) { int i; for (i = 0; i < UART_NR; i++) { struct uart_8250_port *up = &serial8250_ports[i]; if (up->port.dev == dev) serial8250_unregister_port(i); } return 0; } static int serial8250_suspend(struct device *dev, pm_message_t state, u32 level) { int i; if (level != SUSPEND_DISABLE) return 0; for (i = 0; i < UART_NR; i++) { struct uart_8250_port *up = &serial8250_ports[i]; if (up->port.type != PORT_UNKNOWN && up->port.dev == dev) uart_suspend_port(&serial8250_reg, &up->port); } return 0; } static int serial8250_resume(struct device *dev, u32 level) { int i; if (level != RESUME_ENABLE) return 0; for (i = 0; i < UART_NR; i++) { struct uart_8250_port *up = &serial8250_ports[i]; if (up->port.type != PORT_UNKNOWN && up->port.dev == dev) uart_resume_port(&serial8250_reg, &up->port); } return 0; } static struct device_driver serial8250_isa_driver = { .name = "serial8250", .bus = &platform_bus_type, .probe = serial8250_probe, .remove = __devexit_p(serial8250_remove), .suspend = serial8250_suspend, .resume = serial8250_resume, }; /* * This "device" covers _all_ ISA 8250-compatible serial devices listed * in the table in include/asm/serial.h */ static struct platform_device *serial8250_isa_devs; /* * serial8250_register_port and serial8250_unregister_port allows for * 16x50 serial ports to be configured at run-time, to support PCMCIA * modems and PCI multiport cards. */ static DECLARE_MUTEX(serial_sem); static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *port) { int i; /* * First, find a port entry which matches. */ for (i = 0; i < UART_NR; i++) if (uart_match_port(&serial8250_ports[i].port, port)) return &serial8250_ports[i]; /* * We didn't find a matching entry, so look for the first * free entry. We look for one which hasn't been previously * used (indicated by zero iobase). */ for (i = 0; i < UART_NR; i++) if (serial8250_ports[i].port.type == PORT_UNKNOWN && serial8250_ports[i].port.iobase == 0) return &serial8250_ports[i]; /* * That also failed. Last resort is to find any entry which * doesn't have a real port associated with it. */ for (i = 0; i < UART_NR; i++) if (serial8250_ports[i].port.type == PORT_UNKNOWN) return &serial8250_ports[i]; return NULL; } /** * serial8250_register_port - register a serial port * @port: serial port template * * Configure the serial port specified by the request. If the * port exists and is in use, it is hung up and unregistered * first. * * The port is then probed and if necessary the IRQ is autodetected * If this fails an error is returned. * * On success the port is ready to use and the line number is returned. */ int serial8250_register_port(struct uart_port *port) { struct uart_8250_port *uart; int ret = -ENOSPC; if (port->uartclk == 0) return -EINVAL; down(&serial_sem); uart = serial8250_find_match_or_unused(port); if (uart) { uart_remove_one_port(&serial8250_reg, &uart->port); uart->port.iobase = port->iobase; uart->port.membase = port->membase; uart->port.irq = port->irq; uart->port.uartclk = port->uartclk; uart->port.fifosize = port->fifosize; uart->port.regshift = port->regshift; uart->port.iotype = port->iotype; uart->port.flags = port->flags | UPF_BOOT_AUTOCONF; uart->port.mapbase = port->mapbase; if (port->dev) uart->port.dev = port->dev; ret = uart_add_one_port(&serial8250_reg, &uart->port); if (ret == 0) ret = uart->port.line; } up(&serial_sem); return ret; } EXPORT_SYMBOL(serial8250_register_port); /** * serial8250_unregister_port - remove a 16x50 serial port at runtime * @line: serial line number * * Remove one serial port. This may not be called from interrupt * context. We hand the port back to the our control. */ void serial8250_unregister_port(int line) { struct uart_8250_port *uart = &serial8250_ports[line]; down(&serial_sem); uart_remove_one_port(&serial8250_reg, &uart->port); if (serial8250_isa_devs) { uart->port.flags &= ~UPF_BOOT_AUTOCONF; uart->port.type = PORT_UNKNOWN; uart->port.dev = &serial8250_isa_devs->dev; uart_add_one_port(&serial8250_reg, &uart->port); } else { uart->port.dev = NULL; } up(&serial_sem); } EXPORT_SYMBOL(serial8250_unregister_port); static int __init serial8250_init(void) { int ret, i; printk(KERN_INFO "Serial: 8250/16550 driver $Revision: 1.90 $ " "%d ports, IRQ sharing %sabled\n", (int) UART_NR, share_irqs ? "en" : "dis"); for (i = 0; i < NR_IRQS; i++) spin_lock_init(&irq_lists[i].lock); ret = uart_register_driver(&serial8250_reg); if (ret) goto out; serial8250_isa_devs = platform_device_register_simple("serial8250", -1, NULL, 0); if (IS_ERR(serial8250_isa_devs)) { ret = PTR_ERR(serial8250_isa_devs); goto unreg; } serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev); ret = driver_register(&serial8250_isa_driver); if (ret == 0) goto out; platform_device_unregister(serial8250_isa_devs); unreg: uart_unregister_driver(&serial8250_reg); out: return ret; } static void __exit serial8250_exit(void) { struct platform_device *isa_dev = serial8250_isa_devs; /* * This tells serial8250_unregister_port() not to re-register * the ports (thereby making serial8250_isa_driver permanently * in use.) */ serial8250_isa_devs = NULL; driver_unregister(&serial8250_isa_driver); platform_device_unregister(isa_dev); uart_unregister_driver(&serial8250_reg); } module_init(serial8250_init); module_exit(serial8250_exit); EXPORT_SYMBOL(serial8250_suspend_port); EXPORT_SYMBOL(serial8250_resume_port); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Generic 8250/16x50 serial driver $Revision: 1.90 $"); module_param(share_irqs, uint, 0644); MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices" " (unsafe)"); #ifdef CONFIG_SERIAL_8250_RSA module_param_array(probe_rsa, ulong, &probe_rsa_count, 0444); MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA"); #endif MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR); /** * register_serial - configure a 16x50 serial port at runtime * @req: request structure * * Configure the serial port specified by the request. If the * port exists and is in use an error is returned. If the port * is not currently in the table it is added. * * The port is then probed and if necessary the IRQ is autodetected * If this fails an error is returned. * * On success the port is ready to use and the line number is returned. * * Note: this function is deprecated - use serial8250_register_port * instead. */ int register_serial(struct serial_struct *req) { struct uart_port port; port.iobase = req->port; port.membase = req->iomem_base; port.irq = req->irq; port.uartclk = req->baud_base * 16; port.fifosize = req->xmit_fifo_size; port.regshift = req->iomem_reg_shift; port.iotype = req->io_type; port.flags = req->flags | UPF_BOOT_AUTOCONF; port.mapbase = req->iomap_base; port.dev = NULL; if (share_irqs) port.flags |= UPF_SHARE_IRQ; if (HIGH_BITS_OFFSET) port.iobase |= (long) req->port_high << HIGH_BITS_OFFSET; /* * If a clock rate wasn't specified by the low level driver, then * default to the standard clock rate. This should be 115200 (*16) * and should not depend on the architecture's BASE_BAUD definition. * However, since this API will be deprecated, it's probably a * better idea to convert the drivers to use the new API * (serial8250_register_port and serial8250_unregister_port). */ if (port.uartclk == 0) { printk(KERN_WARNING "Serial: registering port at [%08x,%08lx,%p] irq %d with zero baud_base\n", port.iobase, port.mapbase, port.membase, port.irq); printk(KERN_WARNING "Serial: see %s:%d for more information\n", __FILE__, __LINE__); dump_stack(); /* * Fix it up for now, but this is only a temporary measure. */ port.uartclk = BASE_BAUD * 16; } return serial8250_register_port(&port); } EXPORT_SYMBOL(register_serial); /** * unregister_serial - remove a 16x50 serial port at runtime * @line: serial line number * * Remove one serial port. This may not be called from interrupt * context. We hand the port back to our local PM control. * * Note: this function is deprecated - use serial8250_unregister_port * instead. */ void unregister_serial(int line) { serial8250_unregister_port(line); } EXPORT_SYMBOL(unregister_serial);