196fd7ce5SGreg Kroah-Hartman /* 296fd7ce5SGreg Kroah-Hartman * Tty port functions 396fd7ce5SGreg Kroah-Hartman */ 496fd7ce5SGreg Kroah-Hartman 596fd7ce5SGreg Kroah-Hartman #include <linux/types.h> 696fd7ce5SGreg Kroah-Hartman #include <linux/errno.h> 796fd7ce5SGreg Kroah-Hartman #include <linux/tty.h> 896fd7ce5SGreg Kroah-Hartman #include <linux/tty_driver.h> 996fd7ce5SGreg Kroah-Hartman #include <linux/tty_flip.h> 1096fd7ce5SGreg Kroah-Hartman #include <linux/serial.h> 1196fd7ce5SGreg Kroah-Hartman #include <linux/timer.h> 1296fd7ce5SGreg Kroah-Hartman #include <linux/string.h> 1396fd7ce5SGreg Kroah-Hartman #include <linux/slab.h> 1496fd7ce5SGreg Kroah-Hartman #include <linux/sched.h> 1596fd7ce5SGreg Kroah-Hartman #include <linux/init.h> 1696fd7ce5SGreg Kroah-Hartman #include <linux/wait.h> 1796fd7ce5SGreg Kroah-Hartman #include <linux/bitops.h> 1896fd7ce5SGreg Kroah-Hartman #include <linux/delay.h> 1996fd7ce5SGreg Kroah-Hartman #include <linux/module.h> 2096fd7ce5SGreg Kroah-Hartman 2196fd7ce5SGreg Kroah-Hartman void tty_port_init(struct tty_port *port) 2296fd7ce5SGreg Kroah-Hartman { 2396fd7ce5SGreg Kroah-Hartman memset(port, 0, sizeof(*port)); 24ecbbfd44SJiri Slaby tty_buffer_init(port); 2596fd7ce5SGreg Kroah-Hartman init_waitqueue_head(&port->open_wait); 2696fd7ce5SGreg Kroah-Hartman init_waitqueue_head(&port->close_wait); 2796fd7ce5SGreg Kroah-Hartman init_waitqueue_head(&port->delta_msr_wait); 2896fd7ce5SGreg Kroah-Hartman mutex_init(&port->mutex); 2996fd7ce5SGreg Kroah-Hartman mutex_init(&port->buf_mutex); 3096fd7ce5SGreg Kroah-Hartman spin_lock_init(&port->lock); 3196fd7ce5SGreg Kroah-Hartman port->close_delay = (50 * HZ) / 100; 3296fd7ce5SGreg Kroah-Hartman port->closing_wait = (3000 * HZ) / 100; 3396fd7ce5SGreg Kroah-Hartman kref_init(&port->kref); 3496fd7ce5SGreg Kroah-Hartman } 3596fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_init); 3696fd7ce5SGreg Kroah-Hartman 3772a33bf5SJiri Slaby /** 382cb4ca02SJiri Slaby * tty_port_link_device - link tty and tty_port 392cb4ca02SJiri Slaby * @port: tty_port of the device 402cb4ca02SJiri Slaby * @driver: tty_driver for this device 412cb4ca02SJiri Slaby * @index: index of the tty 422cb4ca02SJiri Slaby * 432cb4ca02SJiri Slaby * Provide the tty layer wit ha link from a tty (specified by @index) to a 442cb4ca02SJiri Slaby * tty_port (@port). Use this only if neither tty_port_register_device nor 452cb4ca02SJiri Slaby * tty_port_install is used in the driver. If used, this has to be called before 462cb4ca02SJiri Slaby * tty_register_driver. 472cb4ca02SJiri Slaby */ 482cb4ca02SJiri Slaby void tty_port_link_device(struct tty_port *port, 492cb4ca02SJiri Slaby struct tty_driver *driver, unsigned index) 502cb4ca02SJiri Slaby { 512cb4ca02SJiri Slaby if (WARN_ON(index >= driver->num)) 522cb4ca02SJiri Slaby return; 532cb4ca02SJiri Slaby driver->ports[index] = port; 542cb4ca02SJiri Slaby } 552cb4ca02SJiri Slaby EXPORT_SYMBOL_GPL(tty_port_link_device); 562cb4ca02SJiri Slaby 572cb4ca02SJiri Slaby /** 5872a33bf5SJiri Slaby * tty_port_register_device - register tty device 5972a33bf5SJiri Slaby * @port: tty_port of the device 6072a33bf5SJiri Slaby * @driver: tty_driver for this device 6172a33bf5SJiri Slaby * @index: index of the tty 6272a33bf5SJiri Slaby * @device: parent if exists, otherwise NULL 6372a33bf5SJiri Slaby * 6472a33bf5SJiri Slaby * It is the same as tty_register_device except the provided @port is linked to 6572a33bf5SJiri Slaby * a concrete tty specified by @index. Use this or tty_port_install (or both). 6672a33bf5SJiri Slaby * Call tty_port_link_device as a last resort. 6772a33bf5SJiri Slaby */ 68057eb856SJiri Slaby struct device *tty_port_register_device(struct tty_port *port, 69057eb856SJiri Slaby struct tty_driver *driver, unsigned index, 70057eb856SJiri Slaby struct device *device) 71057eb856SJiri Slaby { 722cb4ca02SJiri Slaby tty_port_link_device(port, driver, index); 73057eb856SJiri Slaby return tty_register_device(driver, index, device); 74057eb856SJiri Slaby } 75057eb856SJiri Slaby EXPORT_SYMBOL_GPL(tty_port_register_device); 76057eb856SJiri Slaby 77b1b79916STomas Hlavacek /** 78b1b79916STomas Hlavacek * tty_port_register_device_attr - register tty device 79b1b79916STomas Hlavacek * @port: tty_port of the device 80b1b79916STomas Hlavacek * @driver: tty_driver for this device 81b1b79916STomas Hlavacek * @index: index of the tty 82b1b79916STomas Hlavacek * @device: parent if exists, otherwise NULL 83b1b79916STomas Hlavacek * @drvdata: Driver data to be set to device. 84b1b79916STomas Hlavacek * @attr_grp: Attribute group to be set on device. 85b1b79916STomas Hlavacek * 86b1b79916STomas Hlavacek * It is the same as tty_register_device_attr except the provided @port is 87b1b79916STomas Hlavacek * linked to a concrete tty specified by @index. Use this or tty_port_install 88b1b79916STomas Hlavacek * (or both). Call tty_port_link_device as a last resort. 89b1b79916STomas Hlavacek */ 90b1b79916STomas Hlavacek struct device *tty_port_register_device_attr(struct tty_port *port, 91b1b79916STomas Hlavacek struct tty_driver *driver, unsigned index, 92b1b79916STomas Hlavacek struct device *device, void *drvdata, 93b1b79916STomas Hlavacek const struct attribute_group **attr_grp) 94b1b79916STomas Hlavacek { 95b1b79916STomas Hlavacek tty_port_link_device(port, driver, index); 96b1b79916STomas Hlavacek return tty_register_device_attr(driver, index, device, drvdata, 97b1b79916STomas Hlavacek attr_grp); 98b1b79916STomas Hlavacek } 99b1b79916STomas Hlavacek EXPORT_SYMBOL_GPL(tty_port_register_device_attr); 100b1b79916STomas Hlavacek 10196fd7ce5SGreg Kroah-Hartman int tty_port_alloc_xmit_buf(struct tty_port *port) 10296fd7ce5SGreg Kroah-Hartman { 10396fd7ce5SGreg Kroah-Hartman /* We may sleep in get_zeroed_page() */ 10496fd7ce5SGreg Kroah-Hartman mutex_lock(&port->buf_mutex); 10596fd7ce5SGreg Kroah-Hartman if (port->xmit_buf == NULL) 10696fd7ce5SGreg Kroah-Hartman port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); 10796fd7ce5SGreg Kroah-Hartman mutex_unlock(&port->buf_mutex); 10896fd7ce5SGreg Kroah-Hartman if (port->xmit_buf == NULL) 10996fd7ce5SGreg Kroah-Hartman return -ENOMEM; 11096fd7ce5SGreg Kroah-Hartman return 0; 11196fd7ce5SGreg Kroah-Hartman } 11296fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_alloc_xmit_buf); 11396fd7ce5SGreg Kroah-Hartman 11496fd7ce5SGreg Kroah-Hartman void tty_port_free_xmit_buf(struct tty_port *port) 11596fd7ce5SGreg Kroah-Hartman { 11696fd7ce5SGreg Kroah-Hartman mutex_lock(&port->buf_mutex); 11796fd7ce5SGreg Kroah-Hartman if (port->xmit_buf != NULL) { 11896fd7ce5SGreg Kroah-Hartman free_page((unsigned long)port->xmit_buf); 11996fd7ce5SGreg Kroah-Hartman port->xmit_buf = NULL; 12096fd7ce5SGreg Kroah-Hartman } 12196fd7ce5SGreg Kroah-Hartman mutex_unlock(&port->buf_mutex); 12296fd7ce5SGreg Kroah-Hartman } 12396fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_free_xmit_buf); 12496fd7ce5SGreg Kroah-Hartman 12596fd7ce5SGreg Kroah-Hartman static void tty_port_destructor(struct kref *kref) 12696fd7ce5SGreg Kroah-Hartman { 12796fd7ce5SGreg Kroah-Hartman struct tty_port *port = container_of(kref, struct tty_port, kref); 12896fd7ce5SGreg Kroah-Hartman if (port->xmit_buf) 12996fd7ce5SGreg Kroah-Hartman free_page((unsigned long)port->xmit_buf); 130ecbbfd44SJiri Slaby tty_buffer_free_all(port); 131*81c79838SJiri Slaby if (port->ops && port->ops->destruct) 13296fd7ce5SGreg Kroah-Hartman port->ops->destruct(port); 13396fd7ce5SGreg Kroah-Hartman else 13496fd7ce5SGreg Kroah-Hartman kfree(port); 13596fd7ce5SGreg Kroah-Hartman } 13696fd7ce5SGreg Kroah-Hartman 13796fd7ce5SGreg Kroah-Hartman void tty_port_put(struct tty_port *port) 13896fd7ce5SGreg Kroah-Hartman { 13996fd7ce5SGreg Kroah-Hartman if (port) 14096fd7ce5SGreg Kroah-Hartman kref_put(&port->kref, tty_port_destructor); 14196fd7ce5SGreg Kroah-Hartman } 14296fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_put); 14396fd7ce5SGreg Kroah-Hartman 14496fd7ce5SGreg Kroah-Hartman /** 14596fd7ce5SGreg Kroah-Hartman * tty_port_tty_get - get a tty reference 14696fd7ce5SGreg Kroah-Hartman * @port: tty port 14796fd7ce5SGreg Kroah-Hartman * 14896fd7ce5SGreg Kroah-Hartman * Return a refcount protected tty instance or NULL if the port is not 14996fd7ce5SGreg Kroah-Hartman * associated with a tty (eg due to close or hangup) 15096fd7ce5SGreg Kroah-Hartman */ 15196fd7ce5SGreg Kroah-Hartman 15296fd7ce5SGreg Kroah-Hartman struct tty_struct *tty_port_tty_get(struct tty_port *port) 15396fd7ce5SGreg Kroah-Hartman { 15496fd7ce5SGreg Kroah-Hartman unsigned long flags; 15596fd7ce5SGreg Kroah-Hartman struct tty_struct *tty; 15696fd7ce5SGreg Kroah-Hartman 15796fd7ce5SGreg Kroah-Hartman spin_lock_irqsave(&port->lock, flags); 15896fd7ce5SGreg Kroah-Hartman tty = tty_kref_get(port->tty); 15996fd7ce5SGreg Kroah-Hartman spin_unlock_irqrestore(&port->lock, flags); 16096fd7ce5SGreg Kroah-Hartman return tty; 16196fd7ce5SGreg Kroah-Hartman } 16296fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_tty_get); 16396fd7ce5SGreg Kroah-Hartman 16496fd7ce5SGreg Kroah-Hartman /** 16596fd7ce5SGreg Kroah-Hartman * tty_port_tty_set - set the tty of a port 16696fd7ce5SGreg Kroah-Hartman * @port: tty port 16796fd7ce5SGreg Kroah-Hartman * @tty: the tty 16896fd7ce5SGreg Kroah-Hartman * 16996fd7ce5SGreg Kroah-Hartman * Associate the port and tty pair. Manages any internal refcounts. 17096fd7ce5SGreg Kroah-Hartman * Pass NULL to deassociate a port 17196fd7ce5SGreg Kroah-Hartman */ 17296fd7ce5SGreg Kroah-Hartman 17396fd7ce5SGreg Kroah-Hartman void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) 17496fd7ce5SGreg Kroah-Hartman { 17596fd7ce5SGreg Kroah-Hartman unsigned long flags; 17696fd7ce5SGreg Kroah-Hartman 17796fd7ce5SGreg Kroah-Hartman spin_lock_irqsave(&port->lock, flags); 17896fd7ce5SGreg Kroah-Hartman if (port->tty) 17996fd7ce5SGreg Kroah-Hartman tty_kref_put(port->tty); 18096fd7ce5SGreg Kroah-Hartman port->tty = tty_kref_get(tty); 18196fd7ce5SGreg Kroah-Hartman spin_unlock_irqrestore(&port->lock, flags); 18296fd7ce5SGreg Kroah-Hartman } 18396fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_tty_set); 18496fd7ce5SGreg Kroah-Hartman 18596fd7ce5SGreg Kroah-Hartman static void tty_port_shutdown(struct tty_port *port) 18696fd7ce5SGreg Kroah-Hartman { 18796fd7ce5SGreg Kroah-Hartman mutex_lock(&port->mutex); 18896fd7ce5SGreg Kroah-Hartman if (port->ops->shutdown && !port->console && 18996fd7ce5SGreg Kroah-Hartman test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) 19096fd7ce5SGreg Kroah-Hartman port->ops->shutdown(port); 19196fd7ce5SGreg Kroah-Hartman mutex_unlock(&port->mutex); 19296fd7ce5SGreg Kroah-Hartman } 19396fd7ce5SGreg Kroah-Hartman 19496fd7ce5SGreg Kroah-Hartman /** 19596fd7ce5SGreg Kroah-Hartman * tty_port_hangup - hangup helper 19696fd7ce5SGreg Kroah-Hartman * @port: tty port 19796fd7ce5SGreg Kroah-Hartman * 19896fd7ce5SGreg Kroah-Hartman * Perform port level tty hangup flag and count changes. Drop the tty 19996fd7ce5SGreg Kroah-Hartman * reference. 20096fd7ce5SGreg Kroah-Hartman */ 20196fd7ce5SGreg Kroah-Hartman 20296fd7ce5SGreg Kroah-Hartman void tty_port_hangup(struct tty_port *port) 20396fd7ce5SGreg Kroah-Hartman { 20496fd7ce5SGreg Kroah-Hartman unsigned long flags; 20596fd7ce5SGreg Kroah-Hartman 20696fd7ce5SGreg Kroah-Hartman spin_lock_irqsave(&port->lock, flags); 20796fd7ce5SGreg Kroah-Hartman port->count = 0; 20896fd7ce5SGreg Kroah-Hartman port->flags &= ~ASYNC_NORMAL_ACTIVE; 20996fd7ce5SGreg Kroah-Hartman if (port->tty) { 21096fd7ce5SGreg Kroah-Hartman set_bit(TTY_IO_ERROR, &port->tty->flags); 21196fd7ce5SGreg Kroah-Hartman tty_kref_put(port->tty); 21296fd7ce5SGreg Kroah-Hartman } 21396fd7ce5SGreg Kroah-Hartman port->tty = NULL; 21496fd7ce5SGreg Kroah-Hartman spin_unlock_irqrestore(&port->lock, flags); 21596fd7ce5SGreg Kroah-Hartman wake_up_interruptible(&port->open_wait); 21696fd7ce5SGreg Kroah-Hartman wake_up_interruptible(&port->delta_msr_wait); 21796fd7ce5SGreg Kroah-Hartman tty_port_shutdown(port); 21896fd7ce5SGreg Kroah-Hartman } 21996fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_hangup); 22096fd7ce5SGreg Kroah-Hartman 22196fd7ce5SGreg Kroah-Hartman /** 22296fd7ce5SGreg Kroah-Hartman * tty_port_carrier_raised - carrier raised check 22396fd7ce5SGreg Kroah-Hartman * @port: tty port 22496fd7ce5SGreg Kroah-Hartman * 22596fd7ce5SGreg Kroah-Hartman * Wrapper for the carrier detect logic. For the moment this is used 22696fd7ce5SGreg Kroah-Hartman * to hide some internal details. This will eventually become entirely 22796fd7ce5SGreg Kroah-Hartman * internal to the tty port. 22896fd7ce5SGreg Kroah-Hartman */ 22996fd7ce5SGreg Kroah-Hartman 23096fd7ce5SGreg Kroah-Hartman int tty_port_carrier_raised(struct tty_port *port) 23196fd7ce5SGreg Kroah-Hartman { 23296fd7ce5SGreg Kroah-Hartman if (port->ops->carrier_raised == NULL) 23396fd7ce5SGreg Kroah-Hartman return 1; 23496fd7ce5SGreg Kroah-Hartman return port->ops->carrier_raised(port); 23596fd7ce5SGreg Kroah-Hartman } 23696fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_carrier_raised); 23796fd7ce5SGreg Kroah-Hartman 23896fd7ce5SGreg Kroah-Hartman /** 23996fd7ce5SGreg Kroah-Hartman * tty_port_raise_dtr_rts - Raise DTR/RTS 24096fd7ce5SGreg Kroah-Hartman * @port: tty port 24196fd7ce5SGreg Kroah-Hartman * 24296fd7ce5SGreg Kroah-Hartman * Wrapper for the DTR/RTS raise logic. For the moment this is used 24396fd7ce5SGreg Kroah-Hartman * to hide some internal details. This will eventually become entirely 24496fd7ce5SGreg Kroah-Hartman * internal to the tty port. 24596fd7ce5SGreg Kroah-Hartman */ 24696fd7ce5SGreg Kroah-Hartman 24796fd7ce5SGreg Kroah-Hartman void tty_port_raise_dtr_rts(struct tty_port *port) 24896fd7ce5SGreg Kroah-Hartman { 24996fd7ce5SGreg Kroah-Hartman if (port->ops->dtr_rts) 25096fd7ce5SGreg Kroah-Hartman port->ops->dtr_rts(port, 1); 25196fd7ce5SGreg Kroah-Hartman } 25296fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_raise_dtr_rts); 25396fd7ce5SGreg Kroah-Hartman 25496fd7ce5SGreg Kroah-Hartman /** 25596fd7ce5SGreg Kroah-Hartman * tty_port_lower_dtr_rts - Lower DTR/RTS 25696fd7ce5SGreg Kroah-Hartman * @port: tty port 25796fd7ce5SGreg Kroah-Hartman * 25896fd7ce5SGreg Kroah-Hartman * Wrapper for the DTR/RTS raise logic. For the moment this is used 25996fd7ce5SGreg Kroah-Hartman * to hide some internal details. This will eventually become entirely 26096fd7ce5SGreg Kroah-Hartman * internal to the tty port. 26196fd7ce5SGreg Kroah-Hartman */ 26296fd7ce5SGreg Kroah-Hartman 26396fd7ce5SGreg Kroah-Hartman void tty_port_lower_dtr_rts(struct tty_port *port) 26496fd7ce5SGreg Kroah-Hartman { 26596fd7ce5SGreg Kroah-Hartman if (port->ops->dtr_rts) 26696fd7ce5SGreg Kroah-Hartman port->ops->dtr_rts(port, 0); 26796fd7ce5SGreg Kroah-Hartman } 26896fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_lower_dtr_rts); 26996fd7ce5SGreg Kroah-Hartman 27096fd7ce5SGreg Kroah-Hartman /** 27196fd7ce5SGreg Kroah-Hartman * tty_port_block_til_ready - Waiting logic for tty open 27296fd7ce5SGreg Kroah-Hartman * @port: the tty port being opened 27396fd7ce5SGreg Kroah-Hartman * @tty: the tty device being bound 27496fd7ce5SGreg Kroah-Hartman * @filp: the file pointer of the opener 27596fd7ce5SGreg Kroah-Hartman * 27696fd7ce5SGreg Kroah-Hartman * Implement the core POSIX/SuS tty behaviour when opening a tty device. 27796fd7ce5SGreg Kroah-Hartman * Handles: 27896fd7ce5SGreg Kroah-Hartman * - hangup (both before and during) 27996fd7ce5SGreg Kroah-Hartman * - non blocking open 28096fd7ce5SGreg Kroah-Hartman * - rts/dtr/dcd 28196fd7ce5SGreg Kroah-Hartman * - signals 28296fd7ce5SGreg Kroah-Hartman * - port flags and counts 28396fd7ce5SGreg Kroah-Hartman * 28496fd7ce5SGreg Kroah-Hartman * The passed tty_port must implement the carrier_raised method if it can 28596fd7ce5SGreg Kroah-Hartman * do carrier detect and the dtr_rts method if it supports software 28696fd7ce5SGreg Kroah-Hartman * management of these lines. Note that the dtr/rts raise is done each 28796fd7ce5SGreg Kroah-Hartman * iteration as a hangup may have previously dropped them while we wait. 28896fd7ce5SGreg Kroah-Hartman */ 28996fd7ce5SGreg Kroah-Hartman 29096fd7ce5SGreg Kroah-Hartman int tty_port_block_til_ready(struct tty_port *port, 29196fd7ce5SGreg Kroah-Hartman struct tty_struct *tty, struct file *filp) 29296fd7ce5SGreg Kroah-Hartman { 29396fd7ce5SGreg Kroah-Hartman int do_clocal = 0, retval; 29496fd7ce5SGreg Kroah-Hartman unsigned long flags; 29596fd7ce5SGreg Kroah-Hartman DEFINE_WAIT(wait); 29696fd7ce5SGreg Kroah-Hartman 29796fd7ce5SGreg Kroah-Hartman /* block if port is in the process of being closed */ 29896fd7ce5SGreg Kroah-Hartman if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) { 29989c8d91eSAlan Cox wait_event_interruptible_tty(tty, port->close_wait, 30096fd7ce5SGreg Kroah-Hartman !(port->flags & ASYNC_CLOSING)); 30196fd7ce5SGreg Kroah-Hartman if (port->flags & ASYNC_HUP_NOTIFY) 30296fd7ce5SGreg Kroah-Hartman return -EAGAIN; 30396fd7ce5SGreg Kroah-Hartman else 30496fd7ce5SGreg Kroah-Hartman return -ERESTARTSYS; 30596fd7ce5SGreg Kroah-Hartman } 30696fd7ce5SGreg Kroah-Hartman 30796fd7ce5SGreg Kroah-Hartman /* if non-blocking mode is set we can pass directly to open unless 30896fd7ce5SGreg Kroah-Hartman the port has just hung up or is in another error state */ 30996fd7ce5SGreg Kroah-Hartman if (tty->flags & (1 << TTY_IO_ERROR)) { 31096fd7ce5SGreg Kroah-Hartman port->flags |= ASYNC_NORMAL_ACTIVE; 31196fd7ce5SGreg Kroah-Hartman return 0; 31296fd7ce5SGreg Kroah-Hartman } 31396fd7ce5SGreg Kroah-Hartman if (filp->f_flags & O_NONBLOCK) { 31496fd7ce5SGreg Kroah-Hartman /* Indicate we are open */ 315adc8d746SAlan Cox if (tty->termios.c_cflag & CBAUD) 31696fd7ce5SGreg Kroah-Hartman tty_port_raise_dtr_rts(port); 31796fd7ce5SGreg Kroah-Hartman port->flags |= ASYNC_NORMAL_ACTIVE; 31896fd7ce5SGreg Kroah-Hartman return 0; 31996fd7ce5SGreg Kroah-Hartman } 32096fd7ce5SGreg Kroah-Hartman 32196fd7ce5SGreg Kroah-Hartman if (C_CLOCAL(tty)) 32296fd7ce5SGreg Kroah-Hartman do_clocal = 1; 32396fd7ce5SGreg Kroah-Hartman 32496fd7ce5SGreg Kroah-Hartman /* Block waiting until we can proceed. We may need to wait for the 32596fd7ce5SGreg Kroah-Hartman carrier, but we must also wait for any close that is in progress 32696fd7ce5SGreg Kroah-Hartman before the next open may complete */ 32796fd7ce5SGreg Kroah-Hartman 32896fd7ce5SGreg Kroah-Hartman retval = 0; 32996fd7ce5SGreg Kroah-Hartman 33096fd7ce5SGreg Kroah-Hartman /* The port lock protects the port counts */ 33196fd7ce5SGreg Kroah-Hartman spin_lock_irqsave(&port->lock, flags); 33296fd7ce5SGreg Kroah-Hartman if (!tty_hung_up_p(filp)) 33396fd7ce5SGreg Kroah-Hartman port->count--; 33496fd7ce5SGreg Kroah-Hartman port->blocked_open++; 33596fd7ce5SGreg Kroah-Hartman spin_unlock_irqrestore(&port->lock, flags); 33696fd7ce5SGreg Kroah-Hartman 33796fd7ce5SGreg Kroah-Hartman while (1) { 33896fd7ce5SGreg Kroah-Hartman /* Indicate we are open */ 339adc8d746SAlan Cox if (tty->termios.c_cflag & CBAUD) 34096fd7ce5SGreg Kroah-Hartman tty_port_raise_dtr_rts(port); 34196fd7ce5SGreg Kroah-Hartman 34296fd7ce5SGreg Kroah-Hartman prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE); 34396fd7ce5SGreg Kroah-Hartman /* Check for a hangup or uninitialised port. 34496fd7ce5SGreg Kroah-Hartman Return accordingly */ 34596fd7ce5SGreg Kroah-Hartman if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) { 34696fd7ce5SGreg Kroah-Hartman if (port->flags & ASYNC_HUP_NOTIFY) 34796fd7ce5SGreg Kroah-Hartman retval = -EAGAIN; 34896fd7ce5SGreg Kroah-Hartman else 34996fd7ce5SGreg Kroah-Hartman retval = -ERESTARTSYS; 35096fd7ce5SGreg Kroah-Hartman break; 35196fd7ce5SGreg Kroah-Hartman } 3520eee50afSJiri Slaby /* 3530eee50afSJiri Slaby * Probe the carrier. For devices with no carrier detect 3540eee50afSJiri Slaby * tty_port_carrier_raised will always return true. 3550eee50afSJiri Slaby * Never ask drivers if CLOCAL is set, this causes troubles 3560eee50afSJiri Slaby * on some hardware. 3570eee50afSJiri Slaby */ 35896fd7ce5SGreg Kroah-Hartman if (!(port->flags & ASYNC_CLOSING) && 3590eee50afSJiri Slaby (do_clocal || tty_port_carrier_raised(port))) 36096fd7ce5SGreg Kroah-Hartman break; 36196fd7ce5SGreg Kroah-Hartman if (signal_pending(current)) { 36296fd7ce5SGreg Kroah-Hartman retval = -ERESTARTSYS; 36396fd7ce5SGreg Kroah-Hartman break; 36496fd7ce5SGreg Kroah-Hartman } 36589c8d91eSAlan Cox tty_unlock(tty); 36696fd7ce5SGreg Kroah-Hartman schedule(); 36789c8d91eSAlan Cox tty_lock(tty); 36896fd7ce5SGreg Kroah-Hartman } 36996fd7ce5SGreg Kroah-Hartman finish_wait(&port->open_wait, &wait); 37096fd7ce5SGreg Kroah-Hartman 37196fd7ce5SGreg Kroah-Hartman /* Update counts. A parallel hangup will have set count to zero and 37296fd7ce5SGreg Kroah-Hartman we must not mess that up further */ 37396fd7ce5SGreg Kroah-Hartman spin_lock_irqsave(&port->lock, flags); 37496fd7ce5SGreg Kroah-Hartman if (!tty_hung_up_p(filp)) 37596fd7ce5SGreg Kroah-Hartman port->count++; 37696fd7ce5SGreg Kroah-Hartman port->blocked_open--; 37796fd7ce5SGreg Kroah-Hartman if (retval == 0) 37896fd7ce5SGreg Kroah-Hartman port->flags |= ASYNC_NORMAL_ACTIVE; 37996fd7ce5SGreg Kroah-Hartman spin_unlock_irqrestore(&port->lock, flags); 38096fd7ce5SGreg Kroah-Hartman return retval; 38196fd7ce5SGreg Kroah-Hartman } 38296fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_block_til_ready); 38396fd7ce5SGreg Kroah-Hartman 38496fd7ce5SGreg Kroah-Hartman int tty_port_close_start(struct tty_port *port, 38596fd7ce5SGreg Kroah-Hartman struct tty_struct *tty, struct file *filp) 38696fd7ce5SGreg Kroah-Hartman { 38796fd7ce5SGreg Kroah-Hartman unsigned long flags; 38896fd7ce5SGreg Kroah-Hartman 38996fd7ce5SGreg Kroah-Hartman spin_lock_irqsave(&port->lock, flags); 39096fd7ce5SGreg Kroah-Hartman if (tty_hung_up_p(filp)) { 39196fd7ce5SGreg Kroah-Hartman spin_unlock_irqrestore(&port->lock, flags); 39296fd7ce5SGreg Kroah-Hartman return 0; 39396fd7ce5SGreg Kroah-Hartman } 39496fd7ce5SGreg Kroah-Hartman 39596fd7ce5SGreg Kroah-Hartman if (tty->count == 1 && port->count != 1) { 39696fd7ce5SGreg Kroah-Hartman printk(KERN_WARNING 39796fd7ce5SGreg Kroah-Hartman "tty_port_close_start: tty->count = 1 port count = %d.\n", 39896fd7ce5SGreg Kroah-Hartman port->count); 39996fd7ce5SGreg Kroah-Hartman port->count = 1; 40096fd7ce5SGreg Kroah-Hartman } 40196fd7ce5SGreg Kroah-Hartman if (--port->count < 0) { 40296fd7ce5SGreg Kroah-Hartman printk(KERN_WARNING "tty_port_close_start: count = %d\n", 40396fd7ce5SGreg Kroah-Hartman port->count); 40496fd7ce5SGreg Kroah-Hartman port->count = 0; 40596fd7ce5SGreg Kroah-Hartman } 40696fd7ce5SGreg Kroah-Hartman 40796fd7ce5SGreg Kroah-Hartman if (port->count) { 40896fd7ce5SGreg Kroah-Hartman spin_unlock_irqrestore(&port->lock, flags); 40996fd7ce5SGreg Kroah-Hartman if (port->ops->drop) 41096fd7ce5SGreg Kroah-Hartman port->ops->drop(port); 41196fd7ce5SGreg Kroah-Hartman return 0; 41296fd7ce5SGreg Kroah-Hartman } 41396fd7ce5SGreg Kroah-Hartman set_bit(ASYNCB_CLOSING, &port->flags); 41496fd7ce5SGreg Kroah-Hartman tty->closing = 1; 41596fd7ce5SGreg Kroah-Hartman spin_unlock_irqrestore(&port->lock, flags); 41696fd7ce5SGreg Kroah-Hartman /* Don't block on a stalled port, just pull the chain */ 41796fd7ce5SGreg Kroah-Hartman if (tty->flow_stopped) 41896fd7ce5SGreg Kroah-Hartman tty_driver_flush_buffer(tty); 41996fd7ce5SGreg Kroah-Hartman if (test_bit(ASYNCB_INITIALIZED, &port->flags) && 42096fd7ce5SGreg Kroah-Hartman port->closing_wait != ASYNC_CLOSING_WAIT_NONE) 421424cc039SJiri Slaby tty_wait_until_sent_from_close(tty, port->closing_wait); 42296fd7ce5SGreg Kroah-Hartman if (port->drain_delay) { 42396fd7ce5SGreg Kroah-Hartman unsigned int bps = tty_get_baud_rate(tty); 42496fd7ce5SGreg Kroah-Hartman long timeout; 42596fd7ce5SGreg Kroah-Hartman 42696fd7ce5SGreg Kroah-Hartman if (bps > 1200) 42796fd7ce5SGreg Kroah-Hartman timeout = max_t(long, 42896fd7ce5SGreg Kroah-Hartman (HZ * 10 * port->drain_delay) / bps, HZ / 10); 42996fd7ce5SGreg Kroah-Hartman else 43096fd7ce5SGreg Kroah-Hartman timeout = 2 * HZ; 43196fd7ce5SGreg Kroah-Hartman schedule_timeout_interruptible(timeout); 43296fd7ce5SGreg Kroah-Hartman } 43396fd7ce5SGreg Kroah-Hartman /* Flush the ldisc buffering */ 43496fd7ce5SGreg Kroah-Hartman tty_ldisc_flush(tty); 43596fd7ce5SGreg Kroah-Hartman 43696fd7ce5SGreg Kroah-Hartman /* Drop DTR/RTS if HUPCL is set. This causes any attached modem to 43796fd7ce5SGreg Kroah-Hartman hang up the line */ 438adc8d746SAlan Cox if (tty->termios.c_cflag & HUPCL) 43996fd7ce5SGreg Kroah-Hartman tty_port_lower_dtr_rts(port); 44096fd7ce5SGreg Kroah-Hartman 44196fd7ce5SGreg Kroah-Hartman /* Don't call port->drop for the last reference. Callers will want 44296fd7ce5SGreg Kroah-Hartman to drop the last active reference in ->shutdown() or the tty 44396fd7ce5SGreg Kroah-Hartman shutdown path */ 44496fd7ce5SGreg Kroah-Hartman return 1; 44596fd7ce5SGreg Kroah-Hartman } 44696fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_close_start); 44796fd7ce5SGreg Kroah-Hartman 44896fd7ce5SGreg Kroah-Hartman void tty_port_close_end(struct tty_port *port, struct tty_struct *tty) 44996fd7ce5SGreg Kroah-Hartman { 45096fd7ce5SGreg Kroah-Hartman unsigned long flags; 45196fd7ce5SGreg Kroah-Hartman 45296fd7ce5SGreg Kroah-Hartman spin_lock_irqsave(&port->lock, flags); 45396fd7ce5SGreg Kroah-Hartman tty->closing = 0; 45496fd7ce5SGreg Kroah-Hartman 45596fd7ce5SGreg Kroah-Hartman if (port->blocked_open) { 45696fd7ce5SGreg Kroah-Hartman spin_unlock_irqrestore(&port->lock, flags); 45796fd7ce5SGreg Kroah-Hartman if (port->close_delay) { 45896fd7ce5SGreg Kroah-Hartman msleep_interruptible( 45996fd7ce5SGreg Kroah-Hartman jiffies_to_msecs(port->close_delay)); 46096fd7ce5SGreg Kroah-Hartman } 46196fd7ce5SGreg Kroah-Hartman spin_lock_irqsave(&port->lock, flags); 46296fd7ce5SGreg Kroah-Hartman wake_up_interruptible(&port->open_wait); 46396fd7ce5SGreg Kroah-Hartman } 46496fd7ce5SGreg Kroah-Hartman port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_CLOSING); 46596fd7ce5SGreg Kroah-Hartman wake_up_interruptible(&port->close_wait); 46696fd7ce5SGreg Kroah-Hartman spin_unlock_irqrestore(&port->lock, flags); 46796fd7ce5SGreg Kroah-Hartman } 46896fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_close_end); 46996fd7ce5SGreg Kroah-Hartman 47096fd7ce5SGreg Kroah-Hartman void tty_port_close(struct tty_port *port, struct tty_struct *tty, 47196fd7ce5SGreg Kroah-Hartman struct file *filp) 47296fd7ce5SGreg Kroah-Hartman { 47396fd7ce5SGreg Kroah-Hartman if (tty_port_close_start(port, tty, filp) == 0) 47496fd7ce5SGreg Kroah-Hartman return; 47596fd7ce5SGreg Kroah-Hartman tty_port_shutdown(port); 47696fd7ce5SGreg Kroah-Hartman set_bit(TTY_IO_ERROR, &tty->flags); 47796fd7ce5SGreg Kroah-Hartman tty_port_close_end(port, tty); 47896fd7ce5SGreg Kroah-Hartman tty_port_tty_set(port, NULL); 47996fd7ce5SGreg Kroah-Hartman } 48096fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_close); 48196fd7ce5SGreg Kroah-Hartman 48272a33bf5SJiri Slaby /** 48372a33bf5SJiri Slaby * tty_port_install - generic tty->ops->install handler 48472a33bf5SJiri Slaby * @port: tty_port of the device 48572a33bf5SJiri Slaby * @driver: tty_driver for this device 48672a33bf5SJiri Slaby * @tty: tty to be installed 48772a33bf5SJiri Slaby * 48872a33bf5SJiri Slaby * It is the same as tty_standard_install except the provided @port is linked 48972a33bf5SJiri Slaby * to a concrete tty specified by @tty. Use this or tty_port_register_device 49072a33bf5SJiri Slaby * (or both). Call tty_port_link_device as a last resort. 49172a33bf5SJiri Slaby */ 492695586caSJiri Slaby int tty_port_install(struct tty_port *port, struct tty_driver *driver, 493695586caSJiri Slaby struct tty_struct *tty) 494695586caSJiri Slaby { 495695586caSJiri Slaby tty->port = port; 496695586caSJiri Slaby return tty_standard_install(driver, tty); 497695586caSJiri Slaby } 498695586caSJiri Slaby EXPORT_SYMBOL_GPL(tty_port_install); 499695586caSJiri Slaby 50096fd7ce5SGreg Kroah-Hartman int tty_port_open(struct tty_port *port, struct tty_struct *tty, 50196fd7ce5SGreg Kroah-Hartman struct file *filp) 50296fd7ce5SGreg Kroah-Hartman { 50396fd7ce5SGreg Kroah-Hartman spin_lock_irq(&port->lock); 50496fd7ce5SGreg Kroah-Hartman if (!tty_hung_up_p(filp)) 50596fd7ce5SGreg Kroah-Hartman ++port->count; 50696fd7ce5SGreg Kroah-Hartman spin_unlock_irq(&port->lock); 50796fd7ce5SGreg Kroah-Hartman tty_port_tty_set(port, tty); 50896fd7ce5SGreg Kroah-Hartman 50996fd7ce5SGreg Kroah-Hartman /* 51096fd7ce5SGreg Kroah-Hartman * Do the device-specific open only if the hardware isn't 51196fd7ce5SGreg Kroah-Hartman * already initialized. Serialize open and shutdown using the 51296fd7ce5SGreg Kroah-Hartman * port mutex. 51396fd7ce5SGreg Kroah-Hartman */ 51496fd7ce5SGreg Kroah-Hartman 51596fd7ce5SGreg Kroah-Hartman mutex_lock(&port->mutex); 51696fd7ce5SGreg Kroah-Hartman 51796fd7ce5SGreg Kroah-Hartman if (!test_bit(ASYNCB_INITIALIZED, &port->flags)) { 51896fd7ce5SGreg Kroah-Hartman clear_bit(TTY_IO_ERROR, &tty->flags); 51996fd7ce5SGreg Kroah-Hartman if (port->ops->activate) { 52096fd7ce5SGreg Kroah-Hartman int retval = port->ops->activate(port, tty); 52196fd7ce5SGreg Kroah-Hartman if (retval) { 52296fd7ce5SGreg Kroah-Hartman mutex_unlock(&port->mutex); 52396fd7ce5SGreg Kroah-Hartman return retval; 52496fd7ce5SGreg Kroah-Hartman } 52596fd7ce5SGreg Kroah-Hartman } 52696fd7ce5SGreg Kroah-Hartman set_bit(ASYNCB_INITIALIZED, &port->flags); 52796fd7ce5SGreg Kroah-Hartman } 52896fd7ce5SGreg Kroah-Hartman mutex_unlock(&port->mutex); 52996fd7ce5SGreg Kroah-Hartman return tty_port_block_til_ready(port, tty, filp); 53096fd7ce5SGreg Kroah-Hartman } 53196fd7ce5SGreg Kroah-Hartman 53296fd7ce5SGreg Kroah-Hartman EXPORT_SYMBOL(tty_port_open); 533