diff options
Diffstat (limited to 'drivers/tty/serial/8250.c')
| -rw-r--r-- | drivers/tty/serial/8250.c | 3387 |
1 files changed, 3387 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c new file mode 100644 index 000000000000..b3b881bc4712 --- /dev/null +++ b/drivers/tty/serial/8250.c @@ -0,0 +1,3387 @@ +/* + * 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. + * + * A note about mapbase / membase + * + * mapbase is the physical address of the IO port. + * membase is an 'ioremapped' cookie. + */ + +#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/delay.h> +#include <linux/platform_device.h> +#include <linux/tty.h> +#include <linux/ratelimit.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 <linux/nmi.h> +#include <linux/mutex.h> +#include <linux/slab.h> + +#include <asm/io.h> +#include <asm/irq.h> + +#include "8250.h" + +#ifdef CONFIG_SPARC +#include "suncore.h" +#endif + +/* + * Configuration: + * share_irqs - whether we pass IRQF_SHARED to request_irq(). This option + * is unsafe when used on edge-triggered interrupts. + */ +static unsigned int share_irqs = SERIAL8250_SHARE_IRQS; + +static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS; + +static struct uart_driver serial8250_reg; + +static int serial_index(struct uart_port *port) +{ + return (serial8250_reg.minor - 64) + port->line; +} + +static unsigned int skip_txen_test; /* force skip of txen test at init time */ + +/* + * 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 + +#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) + + +/* + * 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 const 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 cur_iotype; /* Running I/O type */ + + /* + * Some bits in registers are cleared on a read, so they must + * be saved whenever the register is read but the bits will not + * be immediately processed. + */ +#define LSR_SAVE_FLAGS UART_LSR_BRK_ERROR_BITS + unsigned char lsr_saved_flags; +#define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA + unsigned char msr_saved_flags; +}; + +struct irq_info { + struct hlist_node node; + int irq; + spinlock_t lock; /* Protects list not the hash */ + struct list_head *head; +}; + +#define NR_IRQ_HASH 32 /* Can be adjusted later */ +static struct hlist_head irq_lists[NR_IRQ_HASH]; +static DEFINE_MUTEX(hash_mutex); /* Used to walk the hash */ + +/* + * 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, + /* UART_CAP_EFR breaks billionon CF bluetooth card. */ + .flags = UART_CAP_FIFO | UART_CAP_SLEEP, + }, + [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, + }, + [PORT_RM9000] = { + .name = "RM9000", + .fifo_size = 16, + .tx_loadsz = 16, + .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, + .flags = UART_CAP_FIFO, + }, + [PORT_OCTEON] = { + .name = "OCTEON", + .fifo_size = 64, + .tx_loadsz = 64, + .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, + .flags = UART_CAP_FIFO, + }, + [PORT_AR7] = { + .name = "AR7", + .fifo_size = 16, + .tx_loadsz = 16, + .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00, + .flags = UART_CAP_FIFO | UART_CAP_AFE, + }, + [PORT_U6_16550A] = { + .name = "U6_16550A", + .fifo_size = 64, + .tx_loadsz = 64, + .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, + .flags = UART_CAP_FIFO | UART_CAP_AFE, + }, +}; + +#if defined(CONFIG_MIPS_ALCHEMY) + +/* Au1x00 UART hardware has a weird register layout */ +static const u8 au_io_in_map[] = { + [UART_RX] = 0, + [UART_IER] = 2, + [UART_IIR] = 3, + [UART_LCR] = 5, + [UART_MCR] = 6, + [UART_LSR] = 7, + [UART_MSR] = 8, +}; + +static const u8 au_io_out_map[] = { + [UART_TX] = 1, + [UART_IER] = 2, + [UART_FCR] = 4, + [UART_LCR] = 5, + [UART_MCR] = 6, +}; + +/* sane hardware needs no mapping */ +static inline int map_8250_in_reg(struct uart_port *p, int offset) +{ + if (p->iotype != UPIO_AU) + return offset; + return au_io_in_map[offset]; +} + +static inline int map_8250_out_reg(struct uart_port *p, int offset) +{ + if (p->iotype != UPIO_AU) + return offset; + return au_io_out_map[offset]; +} + +#elif defined(CONFIG_SERIAL_8250_RM9K) + +static const u8 + regmap_in[8] = { + [UART_RX] = 0x00, + [UART_IER] = 0x0c, + [UART_IIR] = 0x14, + [UART_LCR] = 0x1c, + [UART_MCR] = 0x20, + [UART_LSR] = 0x24, + [UART_MSR] = 0x28, + [UART_SCR] = 0x2c + }, + regmap_out[8] = { + [UART_TX] = 0x04, + [UART_IER] = 0x0c, + [UART_FCR] = 0x18, + [UART_LCR] = 0x1c, + [UART_MCR] = 0x20, + [UART_LSR] = 0x24, + [UART_MSR] = 0x28, + [UART_SCR] = 0x2c + }; + +static inline int map_8250_in_reg(struct uart_port *p, int offset) +{ + if (p->iotype != UPIO_RM9000) + return offset; + return regmap_in[offset]; +} + +static inline int map_8250_out_reg(struct uart_port *p, int offset) +{ + if (p->iotype != UPIO_RM9000) + return offset; + return regmap_out[offset]; +} + +#else + +/* sane hardware needs no mapping */ +#define map_8250_in_reg(up, offset) (offset) +#define map_8250_out_reg(up, offset) (offset) + +#endif + +static unsigned int hub6_serial_in(struct uart_port *p, int offset) +{ + offset = map_8250_in_reg(p, offset) << p->regshift; + outb(p->hub6 - 1 + offset, p->iobase); + return inb(p->iobase + 1); +} + +static void hub6_serial_out(struct uart_port *p, int offset, int value) +{ + offset = map_8250_out_reg(p, offset) << p->regshift; + outb(p->hub6 - 1 + offset, p->iobase); + outb(value, p->iobase + 1); +} + +static unsigned int mem_serial_in(struct uart_port *p, int offset) +{ + offset = map_8250_in_reg(p, offset) << p->regshift; + return readb(p->membase + offset); +} + +static void mem_serial_out(struct uart_port *p, int offset, int value) +{ + offset = map_8250_out_reg(p, offset) << p->regshift; + writeb(value, p->membase + offset); +} + +static void mem32_serial_out(struct uart_port *p, int offset, int value) +{ + offset = map_8250_out_reg(p, offset) << p->regshift; + writel(value, p->membase + offset); +} + +static unsigned int mem32_serial_in(struct uart_port *p, int offset) +{ + offset = map_8250_in_reg(p, offset) << p->regshift; + return readl(p->membase + offset); +} + +static unsigned int au_serial_in(struct uart_port *p, int offset) +{ + offset = map_8250_in_reg(p, offset) << p->regshift; + return __raw_readl(p->membase + offset); +} + +static void au_serial_out(struct uart_port *p, int offset, int value) +{ + offset = map_8250_out_reg(p, offset) << p->regshift; + __raw_writel(value, p->membase + offset); +} + +static unsigned int tsi_serial_in(struct uart_port *p, int offset) +{ + unsigned int tmp; + offset = map_8250_in_reg(p, offset) << p->regshift; + if (offset == UART_IIR) { + tmp = readl(p->membase + (UART_IIR & ~3)); + return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */ + } else + return readb(p->membase + offset); +} + +static void tsi_serial_out(struct uart_port *p, int offset, int value) +{ + offset = map_8250_out_reg(p, offset) << p->regshift; + if (!((offset == UART_IER) && (value & UART_IER_UUE))) + writeb(value, p->membase + offset); +} + +/* Save the LCR value so it can be re-written when a Busy Detect IRQ occurs. */ +static inline void dwapb_save_out_value(struct uart_port *p, int offset, + int value) +{ + struct uart_8250_port *up = + container_of(p, struct uart_8250_port, port); + + if (offset == UART_LCR) + up->lcr = value; +} + +/* Read the IER to ensure any interrupt is cleared before returning from ISR. */ +static inline void dwapb_check_clear_ier(struct uart_port *p, int offset) +{ + if (offset == UART_TX || offset == UART_IER) + p->serial_in(p, UART_IER); +} + +static void dwapb_serial_out(struct uart_port *p, int offset, int value) +{ + int save_offset = offset; + offset = map_8250_out_reg(p, offset) << p->regshift; + dwapb_save_out_value(p, save_offset, value); + writeb(value, p->membase + offset); + dwapb_check_clear_ier(p, save_offset); +} + +static void dwapb32_serial_out(struct uart_port *p, int offset, int value) +{ + int save_offset = offset; + offset = map_8250_out_reg(p, offset) << p->regshift; + dwapb_save_out_value(p, save_offset, value); + writel(value, p->membase + offset); + dwapb_check_clear_ier(p, save_offset); +} + +static unsigned int io_serial_in(struct uart_port *p, int offset) +{ + offset = map_8250_in_reg(p, offset) << p->regshift; + return inb(p->iobase + offset); +} + +static void io_serial_out(struct uart_port *p, int offset, int value) +{ + offset = map_8250_out_reg(p, offset) << p->regshift; + outb(value, p->iobase + offset); +} + +static void set_io_from_upio(struct uart_port *p) +{ + struct uart_8250_port *up = + container_of(p, struct uart_8250_port, port); + switch (p->iotype) { + case UPIO_HUB6: + p->serial_in = hub6_serial_in; + p->serial_out = hub6_serial_out; + break; + + case UPIO_MEM: + p->serial_in = mem_serial_in; + p->serial_out = mem_serial_out; + break; + + case UPIO_RM9000: + case UPIO_MEM32: + p->serial_in = mem32_serial_in; + p->serial_out = mem32_serial_out; + break; + + case UPIO_AU: + p->serial_in = au_serial_in; + p->serial_out = au_serial_out; + break; + + case UPIO_TSI: + p->serial_in = tsi_serial_in; + p->serial_out = tsi_serial_out; + break; + + case UPIO_DWAPB: + p->serial_in = mem_serial_in; + p->serial_out = dwapb_serial_out; + break; + + case UPIO_DWAPB32: + p->serial_in = mem32_serial_in; + p->serial_out = dwapb32_serial_out; + break; + + default: + p->serial_in = io_serial_in; + p->serial_out = io_serial_out; + break; + } + /* Remember loaded iotype */ + up->cur_iotype = p->iotype; +} + +static void +serial_out_sync(struct uart_8250_port *up, int offset, int value) +{ + struct uart_port *p = &up->port; + switch (p->iotype) { + case UPIO_MEM: + case UPIO_MEM32: + case UPIO_AU: + case UPIO_DWAPB: + case UPIO_DWAPB32: + p->serial_out(p, offset, value); + p->serial_in(p, UART_LCR); /* safe, no side-effects */ + break; + default: + p->serial_out(p, offset, value); + } +} + +#define serial_in(up, offset) \ + (up->port.serial_in(&(up)->port, (offset))) +#define serial_out(up, offset, value) \ + (up->port.serial_out(&(up)->port, (offset), (value))) +/* + * 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) + +/* Uart divisor latch read */ +static inline int _serial_dl_read(struct uart_8250_port *up) +{ + return serial_inp(up, UART_DLL) | serial_inp(up, UART_DLM) << 8; +} + +/* Uart divisor latch write */ +static inline void _serial_dl_write(struct uart_8250_port *up, int value) +{ + serial_outp(up, UART_DLL, value & 0xff); + serial_outp(up, UART_DLM, value >> 8 & 0xff); +} + +#if defined(CONFIG_MIPS_ALCHEMY) +/* Au1x00 haven't got a standard divisor latch */ +static int serial_dl_read(struct uart_8250_port *up) +{ + if (up->port.iotype == UPIO_AU) + return __raw_readl(up->port.membase + 0x28); + else + return _serial_dl_read(up); +} + +static void serial_dl_write(struct uart_8250_port *up, int value) +{ + if (up->port.iotype == UPIO_AU) + __raw_writel(value, up->port.membase + 0x28); + else + _serial_dl_write(up, value); +} +#elif defined(CONFIG_SERIAL_8250_RM9K) +static int serial_dl_read(struct uart_8250_port *up) +{ + return (up->port.iotype == UPIO_RM9000) ? + (((__raw_readl(up->port.membase + 0x10) << 8) | + (__raw_readl(up->port.membase + 0x08) & 0xff)) & 0xffff) : + _serial_dl_read(up); +} + +static void serial_dl_write(struct uart_8250_port *up, int value) +{ + if (up->port.iotype == UPIO_RM9000) { + __raw_writel(value, up->port.membase + 0x08); + __raw_writel(value >> 8, up->port.membase + 0x10); + } else { + _serial_dl_write(up, value); + } +} +#else +#define serial_dl_read(up) _serial_dl_read(up) +#define serial_dl_write(up, value) _serial_dl_write(up, value) +#endif + +/* + * 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 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 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, UART_LCR_CONF_MODE_B); + 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, UART_LCR_CONF_MODE_B); + 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_lcr; + unsigned short old_dl; + 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_CONF_MODE_A); + old_dl = serial_dl_read(up); + serial_dl_write(up, 0x0001); + 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_CONF_MODE_A); + serial_dl_write(up, old_dl); + 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_CONF_MODE_A); + + 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, UART_LCR_CONF_MODE_B); + 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://linux.derkeiler.com/Mailing-Lists/Kernel/2004-11/4812.html + */ + if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16) + return 1; + + return 0; +} + +static inline int ns16550a_goto_highspeed(struct uart_8250_port *up) +{ + unsigned char status; + + status = serial_in(up, 0x04); /* EXCR2 */ +#define PRESL(x) ((x) & 0x30) + if (PRESL(status) == 0x10) { + /* already in high speed mode */ + return 0; + } else { + status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */ + status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */ + serial_outp(up, 0x04, status); + } + return 1; +} + +/* + * 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_CONF_MODE_A); + 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, UART_LCR_CONF_MODE_B); + 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_dl_read(up); + quot <<= 3; + + if (ns16550a_goto_highspeed(up)) + serial_dl_write(up, quot); + + 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_CONF_MODE_A); + 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); + + /* + * We distinguish between 16550A and U6 16550A by counting + * how many bytes are in the FIFO. + */ + if (up->port.type == PORT_16550A && size_fifo(up) == 64) { + up->port.type = PORT_U6_16550A; + up->capabilities |= UART_CAP_AFE; + } +} + +/* + * 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%04lx, 0x%p): ", + serial_index(&up->port), 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); + + 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 + /* + * Mask out IER[7:4] bits for test as some UARTs (e.g. TL + * 16C754B) allow only to modify them if an EFR bit is set. + */ + scratch2 = serial_inp(up, UART_IER) & 0x0f; + serial_outp(up, UART_IER, 0x0F); +#ifdef __i386__ + outb(0, 0x080); +#endif + scratch3 = serial_inp(up, UART_IER) & 0x0f; + 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 it's 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, UART_LCR_CONF_MODE_B); + 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", + serial_index(&up->port), 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); + serial_in(up, UART_RX); + if (up->capabilities & UART_CAP_UUE) + serial_outp(up, UART_IER, UART_IER_UUE); + else + serial_outp(up, UART_IER, 0); + + out: + spin_unlock_irqrestore(&up->port.lock, 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) +{ + struct uart_8250_port *up = + container_of(port, 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) +{ + struct uart_8250_port *up = + container_of(port, 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; + lsr = serial_in(up, UART_LSR); + up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; + if ((up->port.type == PORT_RM9000) ? + (lsr & UART_LSR_THRE) : + (lsr & UART_LSR_TEMT)) + 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 = + container_of(port, 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 = + container_of(port, struct uart_8250_port, port); + + /* no MSR capabilities */ + if (up->bugs & UART_BUG_NOMSR) + return; + + up->ier |= UART_IER_MSI; + serial_out(up, UART_IER, up->ier); +} + +static void +receive_chars(struct uart_8250_port *up, unsigned int *status) +{ + struct tty_struct *tty = up->port.state->port.tty; + unsigned char ch, lsr = *status; + int max_count = 256; + char flag; + + do { + if (likely(lsr & UART_LSR_DR)) + ch = serial_inp(up, UART_RX); + else + /* + * Intel 82571 has a Serial Over Lan device that will + * set UART_LSR_BI without setting UART_LSR_DR when + * it receives a break. To avoid reading from the + * receive buffer without UART_LSR_DR bit set, we + * just force the read character to be 0 + */ + ch = 0; + + flag = TTY_NORMAL; + up->port.icount.rx++; + + lsr |= up->lsr_saved_flags; + up->lsr_saved_flags = 0; + + if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) { + /* + * 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)) + 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 | UART_LSR_BI)) && (max_count-- > 0)); + spin_unlock(&up->port.lock); + tty_flip_buffer_push(tty); + spin_lock(&up->port.lock); + *status = lsr; +} + +static void transmit_chars(struct uart_8250_port *up) +{ + struct circ_buf *xmit = &up->port.state->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_tx_stopped(&up->port)) { + serial8250_stop_tx(&up->port); + return; + } + if (uart_circ_empty(xmit)) { + __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 unsigned int check_modem_status(struct uart_8250_port *up) +{ + unsigned int status = serial_in(up, UART_MSR); + + status |= up->msr_saved_flags; + up->msr_saved_flags = 0; + if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI && + up->port.state != NULL) { + 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.state->port.delta_msr_wait); + } + + return status; +} + +/* + * This handles the interrupt from one port. + */ +static void serial8250_handle_port(struct uart_8250_port *up) +{ + unsigned int status; + unsigned long flags; + + spin_lock_irqsave(&up->port.lock, flags); + + status = serial_inp(up, UART_LSR); + + DEBUG_INTR("status = %x...", status); + + if (status & (UART_LSR_DR | UART_LSR_BI)) + receive_chars(up, &status); + check_modem_status(up); + if (status & UART_LSR_THRE) + transmit_chars(up); + + spin_unlock_irqrestore(&up->port.lock, flags); +} + +/* + * 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 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)) { + serial8250_handle_port(up); + + handled = 1; + + end = NULL; + } else if ((up->port.iotype == UPIO_DWAPB || + up->port.iotype == UPIO_DWAPB32) && + (iir & UART_IIR_BUSY) == UART_IIR_BUSY) { + /* The DesignWare APB UART has an Busy Detect (0x07) + * interrupt meaning an LCR write attempt occured while the + * UART was busy. The interrupt must be cleared by reading + * the UART status register (USR) and the LCR re-written. */ + unsigned int status; + status = *(volatile u32 *)up->port.private_data; + serial_out(up, UART_LCR, up->lcr); + + 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_ratelimited(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); + /* List empty so throw away the hash node */ + if (i->head == NULL) { + hlist_del(&i->node); + kfree(i); + } +} + +static int serial_link_irq_chain(struct uart_8250_port *up) +{ + struct hlist_head *h; + struct hlist_node *n; + struct irq_info *i; + int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0; + + mutex_lock(&hash_mutex); + + h = &irq_lists[up->port.irq % NR_IRQ_HASH]; + + hlist_for_each(n, h) { + i = hlist_entry(n, struct irq_info, node); + if (i->irq == up->port.irq) + break; + } + + if (n == NULL) { + i = kzalloc(sizeof(struct irq_info), GFP_KERNEL); + if (i == NULL) { + mutex_unlock(&hash_mutex); + return -ENOMEM; + } + spin_lock_init(&i->lock); + i->irq = up->port.irq; + hlist_add_head(&i->node, h); + } + mutex_unlock(&hash_mutex); + + 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); + irq_flags |= up->port.irqflags; + 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; + struct hlist_node *n; + struct hlist_head *h; + + mutex_lock(&hash_mutex); + + h = &irq_lists[up->port.irq % NR_IRQ_HASH]; + + hlist_for_each(n, h) { + i = hlist_entry(n, struct irq_info, node); + if (i->irq == up->port.irq) + break; + } + + BUG_ON(n == NULL); + BUG_ON(i->head == NULL); + + if (list_empty(i->head)) + free_irq(up->port.irq, i); + + serial_do_unlink(i, up); + mutex_unlock(&hash_mutex); +} + +/* + * 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 iir; + + iir = serial_in(up, UART_IIR); + if (!(iir & UART_IIR_NO_INT)) + serial8250_handle_port(up); + mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port)); +} + +static void serial8250_backup_timeout(unsigned long data) +{ + struct uart_8250_port *up = (struct uart_8250_port *)data; + unsigned int iir, ier = 0, lsr; + unsigned long flags; + + /* + * Must disable interrupts or else we risk racing with the interrupt + * based handler. + */ + if (is_real_interrupt(up->port.irq)) { + ier = serial_in(up, UART_IER); + serial_out(up, UART_IER, 0); + } + + iir = serial_in(up, UART_IIR); + + /* + * This should be a safe test for anyone who doesn't trust the + * IIR bits on their UART, but it's specifically designed for + * the "Diva" UART used on the management processor on many HP + * ia64 and parisc boxes. + */ + spin_lock_irqsave(&up->port.lock, flags); + lsr = serial_in(up, UART_LSR); + up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; + spin_unlock_irqrestore(&up->port.lock, flags); + if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) && + (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) && + (lsr & UART_LSR_THRE)) { + iir &= ~(UART_IIR_ID | UART_IIR_NO_INT); + iir |= UART_IIR_THRI; + } + + if (!(iir & UART_IIR_NO_INT)) + serial8250_handle_port(up); + + if (is_real_interrupt(up->port.irq)) + serial_out(up, UART_IER, ier); + + /* Standard timer interval plus 0.2s to keep the port running */ + mod_timer(&up->timer, + jiffies + uart_poll_timeout(&up->port) + HZ / 5); +} + +static unsigned int serial8250_tx_empty(struct uart_port *port) +{ + struct uart_8250_port *up = + container_of(port, struct uart_8250_port, port); + unsigned long flags; + unsigned int lsr; + + spin_lock_irqsave(&up->port.lock, flags); + lsr = serial_in(up, UART_LSR); + up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; + spin_unlock_irqrestore(&up->port.lock, flags); + + return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0; +} + +static unsigned int serial8250_get_mctrl(struct uart_port *port) +{ + struct uart_8250_port *up = + container_of(port, struct uart_8250_port, port); + unsigned int status; + unsigned int ret; + + status = check_modem_status(up); + + 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 = + container_of(port, 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 = + container_of(port, 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); +} + +/* + * Wait for transmitter & holding register to empty + */ +static void wait_for_xmitr(struct uart_8250_port *up, int bits) +{ + unsigned int status, tmout = 10000; + + /* Wait up to 10ms for the character(s) to be sent. */ + for (;;) { + status = serial_in(up, UART_LSR); + + up->lsr_saved_flags |= status & LSR_SAVE_FLAGS; + + if ((status & bits) == bits) + break; + if (--tmout == 0) + break; + udelay(1); + } + + /* Wait up to 1s for flow control if necessary */ + if (up->port.flags & UPF_CONS_FLOW) { + unsigned int tmout; + for (tmout = 1000000; tmout; tmout--) { + unsigned int msr = serial_in(up, UART_MSR); + up->msr_saved_flags |= msr & MSR_SAVE_FLAGS; + if (msr & UART_MSR_CTS) + break; + udelay(1); + touch_nmi_watchdog(); + } + } +} + +#ifdef CONFIG_CONSOLE_POLL +/* + * Console polling routines for writing and reading from the uart while + * in an interrupt or debug context. + */ + +static int serial8250_get_poll_char(struct uart_port *port) +{ + struct uart_8250_port *up = + container_of(port, struct uart_8250_port, port); + unsigned char lsr = serial_inp(up, UART_LSR); + + if (!(lsr & UART_LSR_DR)) + return NO_POLL_CHAR; + + return serial_inp(up, UART_RX); +} + + +static void serial8250_put_poll_char(struct uart_port *port, + unsigned char c) +{ + unsigned int ier; + struct uart_8250_port *up = + container_of(port, struct uart_8250_port, port); + + /* + * First save the IER 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); + + wait_for_xmitr(up, BOTH_EMPTY); + /* + * Send the character out. + * If a LF, also do CR... + */ + serial_out(up, UART_TX, c); + if (c == 10) { + wait_for_xmitr(up, BOTH_EMPTY); + serial_out(up, UART_TX, 13); + } + + /* + * Finally, wait for transmitter to become empty + * and restore the IER + */ + wait_for_xmitr(up, BOTH_EMPTY); + serial_out(up, UART_IER, ier); +} + +#endif /* CONFIG_CONSOLE_POLL */ + +static int serial8250_startup(struct uart_port *port) +{ + struct uart_8250_port *up = + container_of(port, struct uart_8250_port, port); + unsigned long flags; + unsigned char lsr, iir; + int retval; + + up->port.fifosize = uart_config[up->port.type].fifo_size; + up->tx_loadsz = uart_config[up->port.type].tx_loadsz; + up->capabilities = uart_config[up->port.type].flags; + up->mcr = 0; + + if (up->port.iotype != up->cur_iotype) + set_io_from_upio(port); + + if (up->port.type == PORT_16C950) { + /* Wake up and initialize UART */ + up->acr = 0; + serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B); + 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 reenabled 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(KERN_INFO "ttyS%d: LSR safety check engaged!\n", + serial_index(&up->port)); + 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, UART_LCR_CONF_MODE_B); + + 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 (is_real_interrupt(up->port.irq)) { + unsigned char iir1; + /* + * Test for UARTs that do not reassert THRE when the + * transmitter is idle and the interrupt has already + * been cleared. Real 16550s should always reassert + * this interrupt whenever the transmitter is idle and + * the interrupt is enabled. Delays are necessary to + * allow register changes to become visible. + */ + spin_lock_irqsave(&up->port.lock, flags); + if (up->port.irqflags & IRQF_SHARED) + disable_irq_nosync(up->port.irq); + + wait_for_xmitr(up, UART_LSR_THRE); + serial_out_sync(up, UART_IER, UART_IER_THRI); + udelay(1); /* allow THRE to set */ + iir1 = serial_in(up, UART_IIR); + serial_out(up, UART_IER, 0); + serial_out_sync(up, UART_IER, UART_IER_THRI); + udelay(1); /* allow a working UART time to re-assert THRE */ + iir = serial_in(up, UART_IIR); + serial_out(up, UART_IER, 0); + + if (up->port.irqflags & IRQF_SHARED) + enable_irq(up->port.irq); + spin_unlock_irqrestore(&up->port.lock, flags); + + /* + * If the interrupt is not reasserted, setup a timer to + * kick the UART on a regular basis. + */ + if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) { + up->bugs |= UART_BUG_THRE; + pr_debug("ttyS%d - using backup timer\n", + serial_index(port)); + } + } + + /* + * The above check will only give an accurate result the first time + * the port is opened so this value needs to be preserved. + */ + if (up->bugs & UART_BUG_THRE) { + up->timer.function = serial8250_backup_timeout; + up->timer.data = (unsigned long)up; + mod_timer(&up->timer, jiffies + + uart_poll_timeout(port) + HZ / 5); + } + + /* + * 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)) { + up->timer.data = (unsigned long)up; + mod_timer(&up->timer, jiffies + uart_poll_timeout(port)); + } 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); + + /* Serial over Lan (SoL) hack: + Intel 8257x Gigabit ethernet chips have a + 16550 emulation, to be used for Serial Over Lan. + Those chips take a longer time than a normal + serial device to signalize that a transmission + data was queued. Due to that, the above test generally + fails. One solution would be to delay the reading of + iir. However, this is not reliable, since the timeout + is variable. So, let's just don't test if we receive + TX irq. This way, we'll never enable UART_BUG_TXEN. + */ + if (skip_txen_test || up->port.flags & UPF_NO_TXEN_TEST) + goto dont_test_tx_en; + + /* + * 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", + serial_index(port)); + } + } else { + up->bugs &= ~UART_BUG_TXEN; + } + +dont_test_tx_en: + spin_unlock_irqrestore(&up->port.lock, flags); + + /* + * Clear the interrupt registers again for luck, and clear the + * saved flags to avoid getting false values from polling + * routines or the previous session. + */ + serial_inp(up, UART_LSR); + serial_inp(up, UART_RX); + serial_inp(up, UART_IIR); + serial_inp(up, UART_MSR); + up->lsr_saved_flags = 0; + up->msr_saved_flags = 0; + + /* + * 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); + } + + return 0; +} + +static void serial8250_shutdown(struct uart_port *port) +{ + struct uart_8250_port *up = + container_of(port, 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); + + del_timer_sync(&up->timer); + up->timer.function = serial8250_timeout; + if (is_real_interrupt(up->port.irq)) + 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; +} + +void +serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + struct uart_8250_port *up = + container_of(port, 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, + port->uartclk / 16 / 0xffff, + 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 (!(up->bugs & UART_BUG_NOMSR) && + 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, UART_LCR_CONF_MODE_B); + serial_outp(up, UART_EFR, efr); + } + +#ifdef CONFIG_ARCH_OMAP + /* Workaround to enable 115200 baud on OMAP1510 internal ports */ + if (cpu_is_omap1510() && is_omap_port(up)) { + if (baud == 115200) { + quot = 1; + serial_out(up, UART_OMAP_OSC_12M_SEL, 1); + } else + serial_out(up, UART_OMAP_OSC_12M_SEL, 0); + } +#endif + + 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_dl_write(up, quot); + + /* + * 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); + /* Don't rewrite B0 */ + if (tty_termios_baud_rate(termios)) + tty_termios_encode_baud_rate(termios, baud, baud); +} +EXPORT_SYMBOL(serial8250_do_set_termios); + +static void +serial8250_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + if (port->set_termios) + port->set_termios(port, termios, old); + else + serial8250_do_set_termios(port, termios, old); +} + +static void +serial8250_set_ldisc(struct uart_port *port, int new) +{ + if (new == N_PPS) { + port->flags |= UPF_HARDPPS_CD; + serial8250_enable_ms(port); + } else + port->flags &= ~UPF_HARDPPS_CD; +} + + +void serial8250_do_pm(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ + struct uart_8250_port *p = + container_of(port, struct uart_8250_port, port); + + serial8250_set_sleep(p, state != 0); +} +EXPORT_SYMBOL(serial8250_do_pm); + +static void +serial8250_pm(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ + if (port->pm) + port->pm(port, state, oldstate); + else + serial8250_do_pm(port, state, oldstate); +} + +static unsigned int serial8250_port_size(struct uart_8250_port *pt) +{ + if (pt->port.iotype == UPIO_AU) + return 0x1000; +#ifdef CONFIG_ARCH_OMAP + if (is_omap_port(pt)) + return 0x16 << pt->port.regshift; +#endif + return 8 << pt->port.regshift; +} + +/* + * Resource handling. + */ +static int serial8250_request_std_resource(struct uart_8250_port *up) +{ + unsigned int size = serial8250_port_size(up); + int ret = 0; + + switch (up->port.iotype) { + case UPIO_AU: + case UPIO_TSI: + case UPIO_MEM32: + case UPIO_MEM: + case UPIO_DWAPB: + case UPIO_DWAPB32: + 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_nocache(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 = serial8250_port_size(up); + + switch (up->port.iotype) { + case UPIO_AU: + case UPIO_TSI: + case UPIO_MEM32: + case UPIO_MEM: + case UPIO_DWAPB: + case UPIO_DWAPB32: + 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 = -EINVAL; + + switch (up->port.iotype) { + case UPIO_HUB6: + case UPIO_PORT: + start += up->port.iobase; + if (request_region(start, size, "serial-rsa")) + ret = 0; + else + 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_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 = + container_of(port, 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 = + container_of(port, 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 = + container_of(port, struct uart_8250_port, port); + int probeflags = PROBE_ANY; + int ret; + + /* + * 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 (up->port.iotype != up->cur_iotype) + set_io_from_upio(port); + + if (flags & UART_CONFIG_TYPE) + autoconfig(up, probeflags); + + /* if access method is AU, it is a 16550 with a quirk */ + if (up->port.type == PORT_16550A && up->port.iotype == UPIO_AU) + up->bugs |= UART_BUG_NOMSR; + + 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, + .set_ldisc = serial8250_set_ldisc, + .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, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = serial8250_get_poll_char, + .poll_put_char = serial8250_put_poll_char, +#endif +}; + +static struct uart_8250_port serial8250_ports[UART_NR]; + +static void (*serial8250_isa_config)(int port, struct uart_port *up, + unsigned short *capabilities); + +void serial8250_set_isa_configurator( + void (*v)(int port, struct uart_port *up, unsigned short *capabilities)) +{ + serial8250_isa_config = v; +} +EXPORT_SYMBOL(serial8250_set_isa_configurator); + +static void __init serial8250_isa_init_ports(void) +{ + struct uart_8250_port *up; + static int first = 1; + int i, irqflag = 0; + + if (!first) + return; + first = 0; + + for (i = 0; i < nr_uarts; 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; + } + + if (share_irqs) + irqflag = IRQF_SHARED; + + for (i = 0, up = serial8250_ports; + i < ARRAY_SIZE(old_serial_port) && i < nr_uarts; + i++, up++) { + up->port.iobase = old_serial_port[i].port; + up->port.irq = irq_canonicalize(old_serial_port[i].irq); + up->port.irqflags = old_serial_port[i].irqflags; + 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; + set_io_from_upio(&up->port); + up->port.irqflags |= irqflag; + if (serial8250_isa_config != NULL) + serial8250_isa_config(i, &up->port, &up->capabilities); + + } +} + +static void +serial8250_init_fixed_type_port(struct uart_8250_port *up, unsigned int type) +{ + up->port.type = type; + up->port.fifosize = uart_config[type].fifo_size; + up->capabilities = uart_config[type].flags; + up->tx_loadsz = uart_config[type].tx_loadsz; +} + +static void __init +serial8250_register_ports(struct uart_driver *drv, struct device *dev) +{ + int i; + + for (i = 0; i < nr_uarts; i++) { + struct uart_8250_port *up = &serial8250_ports[i]; + up->cur_iotype = 0xFF; + } + + serial8250_isa_init_ports(); + + for (i = 0; i < nr_uarts; i++) { + struct uart_8250_port *up = &serial8250_ports[i]; + + up->port.dev = dev; + + if (up->port.flags & UPF_FIXED_TYPE) + serial8250_init_fixed_type_port(up, up->port.type); + + uart_add_one_port(drv, &up->port); + } +} + +#ifdef CONFIG_SERIAL_8250_CONSOLE + +static void serial8250_console_putchar(struct uart_port *port, int ch) +{ + struct uart_8250_port *up = + container_of(port, struct uart_8250_port, port); + + wait_for_xmitr(up, UART_LSR_THRE); + serial_out(up, UART_TX, ch); +} + +/* + * 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 long flags; + unsigned int ier; + int locked = 1; + + touch_nmi_watchdog(); + + local_irq_save(flags); + if (up->port.sysrq) { + /* serial8250_handle_port() already took the lock */ + locked = 0; + } else if (oops_in_progress) { + locked = spin_trylock(&up->port.lock); + } else + spin_lock(&up->port.lock); + + /* + * First save the IER 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); + + uart_console_write(&up->port, s, count, serial8250_console_putchar); + + /* + * Finally, wait for transmitter to become empty + * and restore the IER + */ + wait_for_xmitr(up, BOTH_EMPTY); + serial_out(up, UART_IER, ier); + + /* + * The receive handling will happen properly because the + * receive ready bit will still be set; it is not cleared + * on read. However, modem control will not, we must + * call it if we have saved something in the saved flags + * while processing with interrupts off. + */ + if (up->msr_saved_flags) + check_modem_status(up); + + if (locked) + spin_unlock(&up->port.lock); + local_irq_restore(flags); +} + +static int __init 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 >= nr_uarts) + 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 int serial8250_console_early_setup(void) +{ + return serial8250_find_port_for_earlycon(); +} + +static struct console serial8250_console = { + .name = "ttyS", + .write = serial8250_console_write, + .device = uart_console_device, + .setup = serial8250_console_setup, + .early_setup = serial8250_console_early_setup, + .flags = CON_PRINTBUFFER | CON_ANYTIME, + .index = -1, + .data = &serial8250_reg, +}; + +static int __init serial8250_console_init(void) +{ + if (nr_uarts > UART_NR) + nr_uarts = UART_NR; + + serial8250_isa_init_ports(); + register_console(&serial8250_console); + return 0; +} +console_initcall(serial8250_console_init); + +int serial8250_find_port(struct uart_port *p) +{ + int line; + struct uart_port *port; + + for (line = 0; line < nr_uarts; line++) { + port = &serial8250_ports[line].port; + if (uart_match_port(p, port)) + return line; + } + return -ENODEV; +} + +#define SERIAL8250_CONSOLE &serial8250_console +#else +#define SERIAL8250_CONSOLE NULL +#endif + +static struct uart_driver serial8250_reg = { + .owner = THIS_MODULE, + .driver_name = "serial", + .dev_name = "ttyS", + .major = TTY_MAJOR, + .minor = 64, + .cons = SERIAL8250_CONSOLE, +}; + +/* + * early_serial_setup - early registration for 8250 ports + * + * Setup an 8250 port structure prior to console initialisation. Use + * after console initialisation will cause undefined behaviour. + */ +int __init early_serial_setup(struct uart_port *port) +{ + struct uart_port *p; + + if (port->line >= ARRAY_SIZE(serial8250_ports)) + return -ENODEV; + + serial8250_isa_init_ports(); + p = &serial8250_ports[port->line].port; + p->iobase = port->iobase; + p->membase = port->membase; + p->irq = port->irq; + p->irqflags = port->irqflags; + p->uartclk = port->uartclk; + p->fifosize = port->fifosize; + p->regshift = port->regshift; + p->iotype = port->iotype; + p->flags = port->flags; + p->mapbase = port->mapbase; + p->private_data = port->private_data; + p->type = port->type; + p->line = port->line; + + set_io_from_upio(p); + if (port->serial_in) + p->serial_in = port->serial_in; + if (port->serial_out) + p->serial_out = port->serial_out; + + return 0; +} + +/** + * serial8250_suspend_port - suspend one serial port + * @line: serial line number + * + * 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 + * + * Resume one serial port. + */ +void serial8250_resume_port(int line) +{ + struct uart_8250_port *up = &serial8250_ports[line]; + + if (up->capabilities & UART_NATSEMI) { + /* Ensure it's still in high speed mode */ + serial_outp(up, UART_LCR, 0xE0); + + ns16550a_goto_highspeed(up); + + serial_outp(up, UART_LCR, 0); + up->port.uartclk = 921600*16; + } + uart_resume_port(&serial8250_reg, &up->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 platform_device *dev) +{ + struct plat_serial8250_port *p = dev->dev.platform_data; + struct uart_port port; + int ret, i, irqflag = 0; + + memset(&port, 0, sizeof(struct uart_port)); + + if (share_irqs) + irqflag = IRQF_SHARED; + + for (i = 0; p && p->flags != 0; p++, i++) { + port.iobase = p->iobase; + port.membase = p->membase; + port.irq = p->irq; + port.irqflags = p->irqflags; + 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.private_data = p->private_data; + port.type = p->type; + port.serial_in = p->serial_in; + port.serial_out = p->serial_out; + port.set_termios = p->set_termios; + port.pm = p->pm; + port.dev = &dev->dev; + port.irqflags |= irqflag; + ret = serial8250_register_port(&port); + if (ret < 0) { + dev_err(&dev->dev, "unable to register port at index %d " + "(IO%lx MEM%llx IRQ%d): %d\n", i, + p->iobase, (unsigned long long)p->mapbase, + p->irq, ret); + } + } + return 0; +} + +/* + * Remove serial ports registered against a platform device. + */ +static int __devexit serial8250_remove(struct platform_device *dev) +{ + int i; + + for (i = 0; i < nr_uarts; i++) { + struct uart_8250_port *up = &serial8250_ports[i]; + + if (up->port.dev == &dev->dev) + serial8250_unregister_port(i); + } + return 0; +} + +static int serial8250_suspend(struct platform_device *dev, pm_message_t state) +{ + int i; + + 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->dev) + uart_suspend_port(&serial8250_reg, &up->port); + } + + return 0; +} + +static int serial8250_resume(struct platform_device *dev) +{ + int i; + + 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->dev) + serial8250_resume_port(i); + } + + return 0; +} + +static struct platform_driver serial8250_isa_driver = { + .probe = serial8250_probe, + .remove = __devexit_p(serial8250_remove), + .suspend = serial8250_suspend, + .resume = serial8250_resume, + .driver = { + .name = "serial8250", + .owner = THIS_MODULE, + }, +}; + +/* + * 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 DEFINE_MUTEX(serial_mutex); + +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 < nr_uarts; 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 < nr_uarts; 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 < nr_uarts; 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; + + mutex_lock(&serial_mutex); + + 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.irqflags = port->irqflags; + 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; + uart->port.private_data = port->private_data; + if (port->dev) + uart->port.dev = port->dev; + + if (port->flags & UPF_FIXED_TYPE) + serial8250_init_fixed_type_port(uart, port->type); + + set_io_from_upio(&uart->port); + /* Possibly override default I/O functions. */ + if (port->serial_in) + uart->port.serial_in = port->serial_in; + if (port->serial_out) + uart->port.serial_out = port->serial_out; + /* Possibly override set_termios call */ + if (port->set_termios) + uart->port.set_termios = port->set_termios; + if (port->pm) + uart->port.pm = port->pm; + + if (serial8250_isa_config != NULL) + serial8250_isa_config(0, &uart->port, + &uart->capabilities); + + ret = uart_add_one_port(&serial8250_reg, &uart->port); + if (ret == 0) + ret = uart->port.line; + } + mutex_unlock(&serial_mutex); + + 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]; + + mutex_lock(&serial_mutex); + 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; + } + mutex_unlock(&serial_mutex); +} +EXPORT_SYMBOL(serial8250_unregister_port); + +static int __init serial8250_init(void) +{ + int ret; + + if (nr_uarts > UART_NR) + nr_uarts = UART_NR; + + printk(KERN_INFO "Serial: 8250/16550 driver, " + "%d ports, IRQ sharing %sabled\n", nr_uarts, + share_irqs ? "en" : "dis"); + +#ifdef CONFIG_SPARC + ret = sunserial_register_minors(&serial8250_reg, UART_NR); +#else + serial8250_reg.nr = UART_NR; + ret = uart_register_driver(&serial8250_reg); +#endif + if (ret) + goto out; + + serial8250_isa_devs = platform_device_alloc("serial8250", + PLAT8250_DEV_LEGACY); + if (!serial8250_isa_devs) { + ret = -ENOMEM; + goto unreg_uart_drv; + } + + ret = platform_device_add(serial8250_isa_devs); + if (ret) + goto put_dev; + + serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev); + + ret = platform_driver_register(&serial8250_isa_driver); + if (ret == 0) + goto out; + + platform_device_del(serial8250_isa_devs); +put_dev: + platform_device_put(serial8250_isa_devs); +unreg_uart_drv: +#ifdef CONFIG_SPARC + sunserial_unregister_minors(&serial8250_reg, UART_NR); +#else + uart_unregister_driver(&serial8250_reg); +#endif +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; + + platform_driver_unregister(&serial8250_isa_driver); + platform_device_unregister(isa_dev); + +#ifdef CONFIG_SPARC + sunserial_unregister_minors(&serial8250_reg, UART_NR); +#else + uart_unregister_driver(&serial8250_reg); +#endif +} + +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"); + +module_param(share_irqs, uint, 0644); +MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices" + " (unsafe)"); + +module_param(nr_uarts, uint, 0644); +MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")"); + +module_param(skip_txen_test, uint, 0644); +MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time"); + +#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); |
