diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_core.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_core.c | 1300 |
1 files changed, 1300 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c new file mode 100644 index 000000000..ab63c308b --- /dev/null +++ b/drivers/tty/serial/8250/8250_core.c @@ -0,0 +1,1300 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Universal/legacy driver for 8250/16550-type serial ports + * + * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. + * + * Copyright (C) 2001 Russell King. + * + * Supports: ISA-compatible 8250/16550 ports + * PNP 8250/16550 ports + * early_serial_setup() ports + * userspace-configurable "phantom" ports + * "serial8250" platform devices + * serial8250_register_8250_port() ports + */ + +#include <linux/acpi.h> +#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/pm_runtime.h> +#include <linux/tty.h> +#include <linux/ratelimit.h> +#include <linux/tty_flip.h> +#include <linux/serial.h> +#include <linux/serial_8250.h> +#include <linux/nmi.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/string_helpers.h> +#include <linux/uaccess.h> +#include <linux/io.h> +#ifdef CONFIG_SPARC +#include <linux/sunserialcore.h> +#endif + +#include <asm/irq.h> + +#include "8250.h" + +/* + * 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 unsigned int skip_txen_test; /* force skip of txen test at init time */ + +#define PASS_LIMIT 512 + +#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 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 */ + +/* + * 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; + + pr_debug("%s(%d): start\n", __func__, irq); + + spin_lock(&i->lock); + + l = i->head; + do { + struct uart_8250_port *up; + struct uart_port *port; + + up = list_entry(l, struct uart_8250_port, list); + port = &up->port; + + if (port->handle_irq(port)) { + handled = 1; + end = NULL; + } else if (end == NULL) + end = l; + + l = l->next; + + if (l == i->head && pass_counter++ > PASS_LIMIT) + break; + } while (l != end); + + spin_unlock(&i->lock); + + pr_debug("%s(%d): end\n", __func__, irq); + + 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 irq_info *i; + int ret; + + mutex_lock(&hash_mutex); + + h = &irq_lists[up->port.irq % NR_IRQ_HASH]; + + hlist_for_each_entry(i, h, node) + if (i->irq == up->port.irq) + break; + + if (i == 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); + ret = request_irq(up->port.irq, serial8250_interrupt, + up->port.irqflags, up->port.name, 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_head *h; + + mutex_lock(&hash_mutex); + + h = &irq_lists[up->port.irq % NR_IRQ_HASH]; + + hlist_for_each_entry(i, h, node) + if (i->irq == up->port.irq) + break; + + BUG_ON(i == 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(struct timer_list *t) +{ + struct uart_8250_port *up = from_timer(up, t, timer); + + up->port.handle_irq(&up->port); + mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port)); +} + +static void serial8250_backup_timeout(struct timer_list *t) +{ + struct uart_8250_port *up = from_timer(up, t, timer); + unsigned int iir, ier = 0, lsr; + unsigned long flags; + + spin_lock_irqsave(&up->port.lock, flags); + + /* + * Must disable interrupts or else we risk racing with the interrupt + * based handler. + */ + if (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. + */ + lsr = serial_lsr_in(up); + 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_tx_chars(up); + + if (up->port.irq) + serial_out(up, UART_IER, ier); + + spin_unlock_irqrestore(&up->port.lock, flags); + + /* Standard timer interval plus 0.2s to keep the port running */ + mod_timer(&up->timer, + jiffies + uart_poll_timeout(&up->port) + HZ / 5); +} + +static void univ8250_setup_timer(struct uart_8250_port *up) +{ + struct uart_port *port = &up->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) { + pr_debug("%s - using backup timer\n", port->name); + + up->timer.function = serial8250_backup_timeout; + 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 (!port->irq) + mod_timer(&up->timer, jiffies + uart_poll_timeout(port)); +} + +static int univ8250_setup_irq(struct uart_8250_port *up) +{ + struct uart_port *port = &up->port; + + if (port->irq) + return serial_link_irq_chain(up); + + return 0; +} + +static void univ8250_release_irq(struct uart_8250_port *up) +{ + struct uart_port *port = &up->port; + + del_timer_sync(&up->timer); + up->timer.function = serial8250_timeout; + if (port->irq) + serial_unlink_irq_chain(up); +} + +#ifdef CONFIG_SERIAL_8250_RSA +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; + struct uart_port *port = &up->port; + int ret = -EINVAL; + + switch (port->iotype) { + case UPIO_HUB6: + case UPIO_PORT: + start += 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; + struct uart_port *port = &up->port; + + switch (port->iotype) { + case UPIO_HUB6: + case UPIO_PORT: + release_region(port->iobase + offset, size); + break; + } +} +#endif + +static const struct uart_ops *base_ops; +static struct uart_ops univ8250_port_ops; + +static const struct uart_8250_ops univ8250_driver_ops = { + .setup_irq = univ8250_setup_irq, + .release_irq = univ8250_release_irq, + .setup_timer = univ8250_setup_timer, +}; + +static struct uart_8250_port serial8250_ports[UART_NR]; + +/** + * serial8250_get_port - retrieve struct uart_8250_port + * @line: serial line number + * + * This function retrieves struct uart_8250_port for the specific line. + * This struct *must* *not* be used to perform a 8250 or serial core operation + * which is not accessible otherwise. Its only purpose is to make the struct + * accessible to the runtime-pm callbacks for context suspend/restore. + * The lock assumption made here is none because runtime-pm suspend/resume + * callbacks should not be invoked if there is any operation performed on the + * port. + */ +struct uart_8250_port *serial8250_get_port(int line) +{ + return &serial8250_ports[line]; +} +EXPORT_SYMBOL_GPL(serial8250_get_port); + +static void (*serial8250_isa_config)(int port, struct uart_port *up, + u32 *capabilities); + +void serial8250_set_isa_configurator( + void (*v)(int port, struct uart_port *up, u32 *capabilities)) +{ + serial8250_isa_config = v; +} +EXPORT_SYMBOL(serial8250_set_isa_configurator); + +#ifdef CONFIG_SERIAL_8250_RSA + +static void univ8250_config_port(struct uart_port *port, int flags) +{ + struct uart_8250_port *up = up_to_u8250p(port); + + up->probe &= ~UART_PROBE_RSA; + if (port->type == PORT_RSA) { + if (serial8250_request_rsa_resource(up) == 0) + up->probe |= UART_PROBE_RSA; + } else if (flags & UART_CONFIG_TYPE) { + int i; + + for (i = 0; i < probe_rsa_count; i++) { + if (probe_rsa[i] == up->port.iobase) { + if (serial8250_request_rsa_resource(up) == 0) + up->probe |= UART_PROBE_RSA; + break; + } + } + } + + base_ops->config_port(port, flags); + + if (port->type != PORT_RSA && up->probe & UART_PROBE_RSA) + serial8250_release_rsa_resource(up); +} + +static int univ8250_request_port(struct uart_port *port) +{ + struct uart_8250_port *up = up_to_u8250p(port); + int ret; + + ret = base_ops->request_port(port); + if (ret == 0 && port->type == PORT_RSA) { + ret = serial8250_request_rsa_resource(up); + if (ret < 0) + base_ops->release_port(port); + } + + return ret; +} + +static void univ8250_release_port(struct uart_port *port) +{ + struct uart_8250_port *up = up_to_u8250p(port); + + if (port->type == PORT_RSA) + serial8250_release_rsa_resource(up); + base_ops->release_port(port); +} + +static void univ8250_rsa_support(struct uart_ops *ops) +{ + ops->config_port = univ8250_config_port; + ops->request_port = univ8250_request_port; + ops->release_port = univ8250_release_port; +} + +#else +#define univ8250_rsa_support(x) do { } while (0) +#endif /* CONFIG_SERIAL_8250_RSA */ + +static inline void serial8250_apply_quirks(struct uart_8250_port *up) +{ + up->port.quirks |= skip_txen_test ? UPQ_NO_TXEN_TEST : 0; +} + +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; + + if (nr_uarts > UART_NR) + nr_uarts = UART_NR; + + for (i = 0; i < nr_uarts; i++) { + struct uart_8250_port *up = &serial8250_ports[i]; + struct uart_port *port = &up->port; + + port->line = i; + serial8250_init_port(up); + if (!base_ops) + base_ops = port->ops; + port->ops = &univ8250_port_ops; + + timer_setup(&up->timer, serial8250_timeout, 0); + + up->ops = &univ8250_driver_ops; + + if (IS_ENABLED(CONFIG_ALPHA_JENSEN) || + (IS_ENABLED(CONFIG_ALPHA_GENERIC) && alpha_jensen())) + port->set_mctrl = alpha_jensen_set_mctrl; + + serial8250_set_defaults(up); + } + + /* chain base port ops to support Remote Supervisor Adapter */ + univ8250_port_ops = *base_ops; + univ8250_rsa_support(&univ8250_port_ops); + + if (share_irqs) + irqflag = IRQF_SHARED; + + for (i = 0, up = serial8250_ports; + i < ARRAY_SIZE(old_serial_port) && i < nr_uarts; + i++, up++) { + struct uart_port *port = &up->port; + + port->iobase = old_serial_port[i].port; + port->irq = irq_canonicalize(old_serial_port[i].irq); + port->irqflags = 0; + port->uartclk = old_serial_port[i].baud_base * 16; + port->flags = old_serial_port[i].flags; + port->hub6 = 0; + port->membase = old_serial_port[i].iomem_base; + port->iotype = old_serial_port[i].io_type; + port->regshift = old_serial_port[i].iomem_reg_shift; + + port->irqflags |= irqflag; + if (serial8250_isa_config != NULL) + serial8250_isa_config(i, &up->port, &up->capabilities); + } +} + +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]; + + if (up->port.type == PORT_8250_CIR) + continue; + + if (up->port.dev) + continue; + + up->port.dev = dev; + + if (uart_console_registered(&up->port)) + pm_runtime_get_sync(up->port.dev); + + serial8250_apply_quirks(up); + uart_add_one_port(drv, &up->port); + } +} + +#ifdef CONFIG_SERIAL_8250_CONSOLE + +static void univ8250_console_write(struct console *co, const char *s, + unsigned int count) +{ + struct uart_8250_port *up = &serial8250_ports[co->index]; + + serial8250_console_write(up, s, count); +} + +static int univ8250_console_setup(struct console *co, char *options) +{ + struct uart_port *port; + int retval; + + /* + * 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; + /* link port to console */ + port->cons = co; + + retval = serial8250_console_setup(port, options, false); + if (retval != 0) + port->cons = NULL; + return retval; +} + +static int univ8250_console_exit(struct console *co) +{ + struct uart_port *port; + + port = &serial8250_ports[co->index].port; + return serial8250_console_exit(port); +} + +/** + * univ8250_console_match - non-standard console matching + * @co: registering console + * @name: name from console command line + * @idx: index from console command line + * @options: ptr to option string from console command line + * + * Only attempts to match console command lines of the form: + * console=uart[8250],io|mmio|mmio16|mmio32,<addr>[,<options>] + * console=uart[8250],0x<addr>[,<options>] + * This form is used to register an initial earlycon boot console and + * replace it with the serial8250_console at 8250 driver init. + * + * Performs console setup for a match (as required by interface) + * If no <options> are specified, then assume the h/w is already setup. + * + * Returns 0 if console matches; otherwise non-zero to use default matching + */ +static int univ8250_console_match(struct console *co, char *name, int idx, + char *options) +{ + char match[] = "uart"; /* 8250-specific earlycon name */ + unsigned char iotype; + resource_size_t addr; + int i; + + if (strncmp(name, match, 4) != 0) + return -ENODEV; + + if (uart_parse_earlycon(options, &iotype, &addr, &options)) + return -ENODEV; + + /* try to match the port specified on the command line */ + for (i = 0; i < nr_uarts; i++) { + struct uart_port *port = &serial8250_ports[i].port; + + if (port->iotype != iotype) + continue; + if ((iotype == UPIO_MEM || iotype == UPIO_MEM16 || + iotype == UPIO_MEM32 || iotype == UPIO_MEM32BE) + && (port->mapbase != addr)) + continue; + if (iotype == UPIO_PORT && port->iobase != addr) + continue; + + co->index = i; + port->cons = co; + return serial8250_console_setup(port, options, true); + } + + return -ENODEV; +} + +static struct console univ8250_console = { + .name = "ttyS", + .write = univ8250_console_write, + .device = uart_console_device, + .setup = univ8250_console_setup, + .exit = univ8250_console_exit, + .match = univ8250_console_match, + .flags = CON_PRINTBUFFER | CON_ANYTIME, + .index = -1, + .data = &serial8250_reg, +}; + +static int __init univ8250_console_init(void) +{ + if (nr_uarts == 0) + return -ENODEV; + + serial8250_isa_init_ports(); + register_console(&univ8250_console); + return 0; +} +console_initcall(univ8250_console_init); + +#define SERIAL8250_CONSOLE (&univ8250_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) || nr_uarts == 0) + 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->mapsize = port->mapsize; + p->private_data = port->private_data; + p->type = port->type; + p->line = port->line; + + serial8250_set_defaults(up_to_u8250p(p)); + + if (port->serial_in) + p->serial_in = port->serial_in; + if (port->serial_out) + p->serial_out = port->serial_out; + if (port->handle_irq) + p->handle_irq = port->handle_irq; + + return 0; +} + +/** + * serial8250_suspend_port - suspend one serial port + * @line: serial line number + * + * Suspend one serial port. + */ +void serial8250_suspend_port(int line) +{ + struct uart_8250_port *up = &serial8250_ports[line]; + struct uart_port *port = &up->port; + + if (!console_suspend_enabled && uart_console(port) && + port->type != PORT_8250) { + unsigned char canary = 0xa5; + + serial_out(up, UART_SCR, canary); + if (serial_in(up, UART_SCR) == canary) + up->canary = canary; + } + + uart_suspend_port(&serial8250_reg, port); +} +EXPORT_SYMBOL(serial8250_suspend_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]; + struct uart_port *port = &up->port; + + up->canary = 0; + + if (up->capabilities & UART_NATSEMI) { + /* Ensure it's still in high speed mode */ + serial_port_out(port, UART_LCR, 0xE0); + + ns16550a_goto_highspeed(up); + + serial_port_out(port, UART_LCR, 0); + port->uartclk = 921600*16; + } + uart_resume_port(&serial8250_reg, port); +} +EXPORT_SYMBOL(serial8250_resume_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 serial8250_probe(struct platform_device *dev) +{ + struct plat_serial8250_port *p = dev_get_platdata(&dev->dev); + struct uart_8250_port uart; + int ret, i, irqflag = 0; + + memset(&uart, 0, sizeof(uart)); + + if (share_irqs) + irqflag = IRQF_SHARED; + + for (i = 0; p && p->flags != 0; p++, i++) { + uart.port.iobase = p->iobase; + uart.port.membase = p->membase; + uart.port.irq = p->irq; + uart.port.irqflags = p->irqflags; + uart.port.uartclk = p->uartclk; + uart.port.regshift = p->regshift; + uart.port.iotype = p->iotype; + uart.port.flags = p->flags; + uart.port.mapbase = p->mapbase; + uart.port.hub6 = p->hub6; + uart.port.has_sysrq = p->has_sysrq; + uart.port.private_data = p->private_data; + uart.port.type = p->type; + uart.port.serial_in = p->serial_in; + uart.port.serial_out = p->serial_out; + uart.port.handle_irq = p->handle_irq; + uart.port.handle_break = p->handle_break; + uart.port.set_termios = p->set_termios; + uart.port.set_ldisc = p->set_ldisc; + uart.port.get_mctrl = p->get_mctrl; + uart.port.pm = p->pm; + uart.port.dev = &dev->dev; + uart.port.irqflags |= irqflag; + ret = serial8250_register_8250_port(&uart); + 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 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 = serial8250_remove, + .suspend = serial8250_suspend, + .resume = serial8250_resume, + .driver = { + .name = "serial8250", + }, +}; + +/* + * 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_8250_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(const 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]; + + /* try line number first if still available */ + i = port->line; + if (i < nr_uarts && serial8250_ports[i].port.type == PORT_UNKNOWN && + serial8250_ports[i].port.iobase == 0) + 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; +} + +static void serial_8250_overrun_backoff_work(struct work_struct *work) +{ + struct uart_8250_port *up = + container_of(to_delayed_work(work), struct uart_8250_port, + overrun_backoff); + struct uart_port *port = &up->port; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + up->ier |= UART_IER_RLSI | UART_IER_RDI; + up->port.read_status_mask |= UART_LSR_DR; + serial_out(up, UART_IER, up->ier); + spin_unlock_irqrestore(&port->lock, flags); +} + +/** + * serial8250_register_8250_port - register a serial port + * @up: 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_8250_port(const struct uart_8250_port *up) +{ + struct uart_8250_port *uart; + int ret = -ENOSPC; + + if (up->port.uartclk == 0) + return -EINVAL; + + mutex_lock(&serial_mutex); + + uart = serial8250_find_match_or_unused(&up->port); + if (uart && uart->port.type != PORT_8250_CIR) { + struct mctrl_gpios *gpios; + + if (uart->port.dev) + uart_remove_one_port(&serial8250_reg, &uart->port); + + uart->port.iobase = up->port.iobase; + uart->port.membase = up->port.membase; + uart->port.irq = up->port.irq; + uart->port.irqflags = up->port.irqflags; + uart->port.uartclk = up->port.uartclk; + uart->port.fifosize = up->port.fifosize; + uart->port.regshift = up->port.regshift; + uart->port.iotype = up->port.iotype; + uart->port.flags = up->port.flags | UPF_BOOT_AUTOCONF; + uart->bugs = up->bugs; + uart->port.mapbase = up->port.mapbase; + uart->port.mapsize = up->port.mapsize; + uart->port.private_data = up->port.private_data; + uart->tx_loadsz = up->tx_loadsz; + uart->capabilities = up->capabilities; + uart->port.throttle = up->port.throttle; + uart->port.unthrottle = up->port.unthrottle; + uart->port.rs485_config = up->port.rs485_config; + uart->port.rs485_supported = up->port.rs485_supported; + uart->port.rs485 = up->port.rs485; + uart->rs485_start_tx = up->rs485_start_tx; + uart->rs485_stop_tx = up->rs485_stop_tx; + uart->lsr_save_mask = up->lsr_save_mask; + uart->dma = up->dma; + + /* Take tx_loadsz from fifosize if it wasn't set separately */ + if (uart->port.fifosize && !uart->tx_loadsz) + uart->tx_loadsz = uart->port.fifosize; + + if (up->port.dev) { + uart->port.dev = up->port.dev; + ret = uart_get_rs485_mode(&uart->port); + if (ret) + goto err; + } + + if (up->port.flags & UPF_FIXED_TYPE) + uart->port.type = up->port.type; + + /* + * Only call mctrl_gpio_init(), if the device has no ACPI + * companion device + */ + if (!has_acpi_companion(uart->port.dev)) { + gpios = mctrl_gpio_init(&uart->port, 0); + if (IS_ERR(gpios)) { + ret = PTR_ERR(gpios); + goto err; + } else { + uart->gpios = gpios; + } + } + + serial8250_set_defaults(uart); + + /* Possibly override default I/O functions. */ + if (up->port.serial_in) + uart->port.serial_in = up->port.serial_in; + if (up->port.serial_out) + uart->port.serial_out = up->port.serial_out; + if (up->port.handle_irq) + uart->port.handle_irq = up->port.handle_irq; + /* Possibly override set_termios call */ + if (up->port.set_termios) + uart->port.set_termios = up->port.set_termios; + if (up->port.set_ldisc) + uart->port.set_ldisc = up->port.set_ldisc; + if (up->port.get_mctrl) + uart->port.get_mctrl = up->port.get_mctrl; + if (up->port.set_mctrl) + uart->port.set_mctrl = up->port.set_mctrl; + if (up->port.get_divisor) + uart->port.get_divisor = up->port.get_divisor; + if (up->port.set_divisor) + uart->port.set_divisor = up->port.set_divisor; + if (up->port.startup) + uart->port.startup = up->port.startup; + if (up->port.shutdown) + uart->port.shutdown = up->port.shutdown; + if (up->port.pm) + uart->port.pm = up->port.pm; + if (up->port.handle_break) + uart->port.handle_break = up->port.handle_break; + if (up->dl_read) + uart->dl_read = up->dl_read; + if (up->dl_write) + uart->dl_write = up->dl_write; + + if (uart->port.type != PORT_8250_CIR) { + if (serial8250_isa_config != NULL) + serial8250_isa_config(0, &uart->port, + &uart->capabilities); + + serial8250_apply_quirks(uart); + ret = uart_add_one_port(&serial8250_reg, + &uart->port); + if (ret) + goto err; + + ret = uart->port.line; + } else { + dev_info(uart->port.dev, + "skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n", + uart->port.iobase, + (unsigned long long)uart->port.mapbase, + uart->port.irq); + + ret = 0; + } + + if (!uart->lsr_save_mask) + uart->lsr_save_mask = LSR_SAVE_FLAGS; /* Use default LSR mask */ + + /* Initialise interrupt backoff work if required */ + if (up->overrun_backoff_time_ms > 0) { + uart->overrun_backoff_time_ms = + up->overrun_backoff_time_ms; + INIT_DELAYED_WORK(&uart->overrun_backoff, + serial_8250_overrun_backoff_work); + } else { + uart->overrun_backoff_time_ms = 0; + } + } + + mutex_unlock(&serial_mutex); + + return ret; + +err: + uart->port.dev = NULL; + mutex_unlock(&serial_mutex); + return ret; +} +EXPORT_SYMBOL(serial8250_register_8250_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); + + if (uart->em485) { + unsigned long flags; + + spin_lock_irqsave(&uart->port.lock, flags); + serial8250_em485_destroy(uart); + spin_unlock_irqrestore(&uart->port.lock, flags); + } + + 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->capabilities = 0; + serial8250_apply_quirks(uart); + 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 == 0) + return -ENODEV; + + serial8250_isa_init_ports(); + + pr_info("Serial: 8250/16550 driver, %d ports, IRQ sharing %s\n", + nr_uarts, str_enabled_disabled(share_irqs)); + +#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; + + ret = serial8250_pnp_init(); + if (ret) + goto unreg_uart_drv; + + serial8250_isa_devs = platform_device_alloc("serial8250", + PLAT8250_DEV_LEGACY); + if (!serial8250_isa_devs) { + ret = -ENOMEM; + goto unreg_pnp; + } + + 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_pnp: + serial8250_pnp_exit(); +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); + + serial8250_pnp_exit(); + +#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); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Generic 8250/16x50 serial driver"); + +module_param_hw(share_irqs, uint, other, 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_hw_array(probe_rsa, ulong, ioport, &probe_rsa_count, 0444); +MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA"); +#endif +MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR); + +#ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS +#ifndef MODULE +/* This module was renamed to 8250_core in 3.7. Keep the old "8250" name + * working as well for the module options so we don't break people. We + * need to keep the names identical and the convenient macros will happily + * refuse to let us do that by failing the build with redefinition errors + * of global variables. So we stick them inside a dummy function to avoid + * those conflicts. The options still get parsed, and the redefined + * MODULE_PARAM_PREFIX lets us keep the "8250." syntax alive. + * + * This is hacky. I'm sorry. + */ +static void __used s8250_options(void) +{ +#undef MODULE_PARAM_PREFIX +#define MODULE_PARAM_PREFIX "8250_core." + + module_param_cb(share_irqs, ¶m_ops_uint, &share_irqs, 0644); + module_param_cb(nr_uarts, ¶m_ops_uint, &nr_uarts, 0644); + module_param_cb(skip_txen_test, ¶m_ops_uint, &skip_txen_test, 0644); +#ifdef CONFIG_SERIAL_8250_RSA + __module_param_call(MODULE_PARAM_PREFIX, probe_rsa, + ¶m_array_ops, .arr = &__param_arr_probe_rsa, + 0444, -1, 0); +#endif +} +#else +MODULE_ALIAS("8250_core"); +#endif +#endif |