Greg Kroah-Hartman | e3b3d0f | 2017-11-06 18:11:51 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 2 | /* |
| 3 | * Tty port functions |
| 4 | */ |
| 5 | |
| 6 | #include <linux/types.h> |
| 7 | #include <linux/errno.h> |
| 8 | #include <linux/tty.h> |
| 9 | #include <linux/tty_driver.h> |
| 10 | #include <linux/tty_flip.h> |
Alan Cox | 3e61696 | 2009-01-02 13:45:26 +0000 | [diff] [blame] | 11 | #include <linux/serial.h> |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 12 | #include <linux/timer.h> |
| 13 | #include <linux/string.h> |
| 14 | #include <linux/slab.h> |
Ingo Molnar | 174cd4b | 2017-02-02 19:15:33 +0100 | [diff] [blame] | 15 | #include <linux/sched/signal.h> |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 16 | #include <linux/wait.h> |
| 17 | #include <linux/bitops.h> |
| 18 | #include <linux/delay.h> |
| 19 | #include <linux/module.h> |
Johan Hovold | 8cde11b | 2017-05-18 17:33:00 +0200 | [diff] [blame] | 20 | #include <linux/serdev.h> |
Greg Kroah-Hartman | 98602c0 | 2021-04-08 14:51:22 +0200 | [diff] [blame] | 21 | #include "tty.h" |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 22 | |
Rob Herring | c3485ee | 2017-02-02 13:48:05 -0600 | [diff] [blame] | 23 | static int tty_port_default_receive_buf(struct tty_port *port, |
| 24 | const unsigned char *p, |
| 25 | const unsigned char *f, size_t count) |
| 26 | { |
| 27 | int ret; |
| 28 | struct tty_struct *tty; |
| 29 | struct tty_ldisc *disc; |
| 30 | |
| 31 | tty = READ_ONCE(port->itty); |
| 32 | if (!tty) |
| 33 | return 0; |
| 34 | |
| 35 | disc = tty_ldisc_ref(tty); |
| 36 | if (!disc) |
| 37 | return 0; |
| 38 | |
| 39 | ret = tty_ldisc_receive_buf(disc, p, (char *)f, count); |
| 40 | |
| 41 | tty_ldisc_deref(disc); |
| 42 | |
| 43 | return ret; |
| 44 | } |
| 45 | |
| 46 | static void tty_port_default_wakeup(struct tty_port *port) |
| 47 | { |
| 48 | struct tty_struct *tty = tty_port_tty_get(port); |
| 49 | |
| 50 | if (tty) { |
| 51 | tty_wakeup(tty); |
| 52 | tty_kref_put(tty); |
| 53 | } |
| 54 | } |
| 55 | |
Johan Hovold | 0c5aae5 | 2020-02-10 15:57:30 +0100 | [diff] [blame] | 56 | const struct tty_port_client_operations tty_port_default_client_ops = { |
Rob Herring | c3485ee | 2017-02-02 13:48:05 -0600 | [diff] [blame] | 57 | .receive_buf = tty_port_default_receive_buf, |
| 58 | .write_wakeup = tty_port_default_wakeup, |
| 59 | }; |
Johan Hovold | 0c5aae5 | 2020-02-10 15:57:30 +0100 | [diff] [blame] | 60 | EXPORT_SYMBOL_GPL(tty_port_default_client_ops); |
Rob Herring | c3485ee | 2017-02-02 13:48:05 -0600 | [diff] [blame] | 61 | |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 62 | void tty_port_init(struct tty_port *port) |
| 63 | { |
| 64 | memset(port, 0, sizeof(*port)); |
Jiri Slaby | ecbbfd4 | 2012-10-18 22:26:47 +0200 | [diff] [blame] | 65 | tty_buffer_init(port); |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 66 | init_waitqueue_head(&port->open_wait); |
Alan Cox | bdc04e3 | 2009-09-19 13:13:31 -0700 | [diff] [blame] | 67 | init_waitqueue_head(&port->delta_msr_wait); |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 68 | mutex_init(&port->mutex); |
Alan Cox | 44e4909 | 2009-11-30 13:16:41 +0000 | [diff] [blame] | 69 | mutex_init(&port->buf_mutex); |
Alan Cox | 4a90f09 | 2008-10-13 10:39:46 +0100 | [diff] [blame] | 70 | spin_lock_init(&port->lock); |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 71 | port->close_delay = (50 * HZ) / 100; |
| 72 | port->closing_wait = (3000 * HZ) / 100; |
Johan Hovold | 0c5aae5 | 2020-02-10 15:57:30 +0100 | [diff] [blame] | 73 | port->client_ops = &tty_port_default_client_ops; |
Alan Cox | 568aafc | 2009-11-30 13:17:14 +0000 | [diff] [blame] | 74 | kref_init(&port->kref); |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 75 | } |
| 76 | EXPORT_SYMBOL(tty_port_init); |
| 77 | |
Jiri Slaby | 72a33bf | 2012-08-07 21:47:49 +0200 | [diff] [blame] | 78 | /** |
Jiri Slaby | 2cb4ca0 | 2012-08-07 21:47:50 +0200 | [diff] [blame] | 79 | * tty_port_link_device - link tty and tty_port |
| 80 | * @port: tty_port of the device |
| 81 | * @driver: tty_driver for this device |
| 82 | * @index: index of the tty |
| 83 | * |
Antonio Borneo | 1926e5d | 2017-09-08 08:59:42 +0200 | [diff] [blame] | 84 | * Provide the tty layer with a link from a tty (specified by @index) to a |
Jiri Slaby | 2cb4ca0 | 2012-08-07 21:47:50 +0200 | [diff] [blame] | 85 | * tty_port (@port). Use this only if neither tty_port_register_device nor |
| 86 | * tty_port_install is used in the driver. If used, this has to be called before |
| 87 | * tty_register_driver. |
| 88 | */ |
| 89 | void tty_port_link_device(struct tty_port *port, |
| 90 | struct tty_driver *driver, unsigned index) |
| 91 | { |
| 92 | if (WARN_ON(index >= driver->num)) |
| 93 | return; |
Sudip Mukherjee | 273f6329 | 2019-12-27 17:44:34 +0000 | [diff] [blame] | 94 | driver->ports[index] = port; |
Jiri Slaby | 2cb4ca0 | 2012-08-07 21:47:50 +0200 | [diff] [blame] | 95 | } |
| 96 | EXPORT_SYMBOL_GPL(tty_port_link_device); |
| 97 | |
| 98 | /** |
Jiri Slaby | 72a33bf | 2012-08-07 21:47:49 +0200 | [diff] [blame] | 99 | * tty_port_register_device - register tty device |
| 100 | * @port: tty_port of the device |
| 101 | * @driver: tty_driver for this device |
| 102 | * @index: index of the tty |
| 103 | * @device: parent if exists, otherwise NULL |
| 104 | * |
| 105 | * It is the same as tty_register_device except the provided @port is linked to |
| 106 | * a concrete tty specified by @index. Use this or tty_port_install (or both). |
| 107 | * Call tty_port_link_device as a last resort. |
| 108 | */ |
Jiri Slaby | 057eb85 | 2012-06-04 13:35:37 +0200 | [diff] [blame] | 109 | struct device *tty_port_register_device(struct tty_port *port, |
| 110 | struct tty_driver *driver, unsigned index, |
| 111 | struct device *device) |
| 112 | { |
Rob Herring | 3086365 | 2017-01-16 16:54:30 -0600 | [diff] [blame] | 113 | return tty_port_register_device_attr(port, driver, index, device, NULL, NULL); |
Jiri Slaby | 057eb85 | 2012-06-04 13:35:37 +0200 | [diff] [blame] | 114 | } |
| 115 | EXPORT_SYMBOL_GPL(tty_port_register_device); |
| 116 | |
Tomas Hlavacek | b1b7991 | 2012-09-06 23:17:47 +0200 | [diff] [blame] | 117 | /** |
| 118 | * tty_port_register_device_attr - register tty device |
| 119 | * @port: tty_port of the device |
| 120 | * @driver: tty_driver for this device |
| 121 | * @index: index of the tty |
| 122 | * @device: parent if exists, otherwise NULL |
| 123 | * @drvdata: Driver data to be set to device. |
| 124 | * @attr_grp: Attribute group to be set on device. |
| 125 | * |
| 126 | * It is the same as tty_register_device_attr except the provided @port is |
| 127 | * linked to a concrete tty specified by @index. Use this or tty_port_install |
| 128 | * (or both). Call tty_port_link_device as a last resort. |
| 129 | */ |
| 130 | struct device *tty_port_register_device_attr(struct tty_port *port, |
| 131 | struct tty_driver *driver, unsigned index, |
| 132 | struct device *device, void *drvdata, |
| 133 | const struct attribute_group **attr_grp) |
| 134 | { |
| 135 | tty_port_link_device(port, driver, index); |
| 136 | return tty_register_device_attr(driver, index, device, drvdata, |
| 137 | attr_grp); |
| 138 | } |
| 139 | EXPORT_SYMBOL_GPL(tty_port_register_device_attr); |
| 140 | |
Johan Hovold | 8cde11b | 2017-05-18 17:33:00 +0200 | [diff] [blame] | 141 | /** |
| 142 | * tty_port_register_device_attr_serdev - register tty or serdev device |
| 143 | * @port: tty_port of the device |
| 144 | * @driver: tty_driver for this device |
| 145 | * @index: index of the tty |
| 146 | * @device: parent if exists, otherwise NULL |
| 147 | * @drvdata: driver data for the device |
| 148 | * @attr_grp: attribute group for the device |
| 149 | * |
| 150 | * Register a serdev or tty device depending on if the parent device has any |
| 151 | * defined serdev clients or not. |
| 152 | */ |
| 153 | struct device *tty_port_register_device_attr_serdev(struct tty_port *port, |
| 154 | struct tty_driver *driver, unsigned index, |
| 155 | struct device *device, void *drvdata, |
| 156 | const struct attribute_group **attr_grp) |
| 157 | { |
| 158 | struct device *dev; |
| 159 | |
| 160 | tty_port_link_device(port, driver, index); |
| 161 | |
| 162 | dev = serdev_tty_port_register(port, device, driver, index); |
| 163 | if (PTR_ERR(dev) != -ENODEV) { |
| 164 | /* Skip creating cdev if we registered a serdev device */ |
| 165 | return dev; |
| 166 | } |
| 167 | |
| 168 | return tty_register_device_attr(driver, index, device, drvdata, |
| 169 | attr_grp); |
| 170 | } |
| 171 | EXPORT_SYMBOL_GPL(tty_port_register_device_attr_serdev); |
| 172 | |
| 173 | /** |
| 174 | * tty_port_register_device_serdev - register tty or serdev device |
| 175 | * @port: tty_port of the device |
| 176 | * @driver: tty_driver for this device |
| 177 | * @index: index of the tty |
| 178 | * @device: parent if exists, otherwise NULL |
| 179 | * |
| 180 | * Register a serdev or tty device depending on if the parent device has any |
| 181 | * defined serdev clients or not. |
| 182 | */ |
| 183 | struct device *tty_port_register_device_serdev(struct tty_port *port, |
| 184 | struct tty_driver *driver, unsigned index, |
| 185 | struct device *device) |
| 186 | { |
| 187 | return tty_port_register_device_attr_serdev(port, driver, index, |
| 188 | device, NULL, NULL); |
| 189 | } |
| 190 | EXPORT_SYMBOL_GPL(tty_port_register_device_serdev); |
| 191 | |
| 192 | /** |
| 193 | * tty_port_unregister_device - deregister a tty or serdev device |
| 194 | * @port: tty_port of the device |
| 195 | * @driver: tty_driver for this device |
| 196 | * @index: index of the tty |
| 197 | * |
| 198 | * If a tty or serdev device is registered with a call to |
| 199 | * tty_port_register_device_serdev() then this function must be called when |
| 200 | * the device is gone. |
| 201 | */ |
| 202 | void tty_port_unregister_device(struct tty_port *port, |
| 203 | struct tty_driver *driver, unsigned index) |
| 204 | { |
| 205 | int ret; |
| 206 | |
| 207 | ret = serdev_tty_port_unregister(port); |
| 208 | if (ret == 0) |
| 209 | return; |
| 210 | |
| 211 | tty_unregister_device(driver, index); |
| 212 | } |
| 213 | EXPORT_SYMBOL_GPL(tty_port_unregister_device); |
| 214 | |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 215 | int tty_port_alloc_xmit_buf(struct tty_port *port) |
| 216 | { |
| 217 | /* We may sleep in get_zeroed_page() */ |
Alan Cox | 44e4909 | 2009-11-30 13:16:41 +0000 | [diff] [blame] | 218 | mutex_lock(&port->buf_mutex); |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 219 | if (port->xmit_buf == NULL) |
| 220 | port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); |
Alan Cox | 44e4909 | 2009-11-30 13:16:41 +0000 | [diff] [blame] | 221 | mutex_unlock(&port->buf_mutex); |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 222 | if (port->xmit_buf == NULL) |
| 223 | return -ENOMEM; |
| 224 | return 0; |
| 225 | } |
| 226 | EXPORT_SYMBOL(tty_port_alloc_xmit_buf); |
| 227 | |
| 228 | void tty_port_free_xmit_buf(struct tty_port *port) |
| 229 | { |
Alan Cox | 44e4909 | 2009-11-30 13:16:41 +0000 | [diff] [blame] | 230 | mutex_lock(&port->buf_mutex); |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 231 | if (port->xmit_buf != NULL) { |
| 232 | free_page((unsigned long)port->xmit_buf); |
| 233 | port->xmit_buf = NULL; |
| 234 | } |
Alan Cox | 44e4909 | 2009-11-30 13:16:41 +0000 | [diff] [blame] | 235 | mutex_unlock(&port->buf_mutex); |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 236 | } |
| 237 | EXPORT_SYMBOL(tty_port_free_xmit_buf); |
| 238 | |
Jiri Slaby | de274bf | 2012-11-15 09:49:54 +0100 | [diff] [blame] | 239 | /** |
| 240 | * tty_port_destroy -- destroy inited port |
Antonio Borneo | 1926e5d | 2017-09-08 08:59:42 +0200 | [diff] [blame] | 241 | * @port: tty port to be destroyed |
Jiri Slaby | de274bf | 2012-11-15 09:49:54 +0100 | [diff] [blame] | 242 | * |
| 243 | * When a port was initialized using tty_port_init, one has to destroy the |
| 244 | * port by this function. Either indirectly by using tty_port refcounting |
| 245 | * (tty_port_put) or directly if refcounting is not used. |
| 246 | */ |
| 247 | void tty_port_destroy(struct tty_port *port) |
| 248 | { |
Peter Hurley | e176058 | 2015-10-17 16:36:23 -0400 | [diff] [blame] | 249 | tty_buffer_cancel_work(port); |
Jiri Slaby | de274bf | 2012-11-15 09:49:54 +0100 | [diff] [blame] | 250 | tty_buffer_free_all(port); |
| 251 | } |
| 252 | EXPORT_SYMBOL(tty_port_destroy); |
| 253 | |
Alan Cox | 568aafc | 2009-11-30 13:17:14 +0000 | [diff] [blame] | 254 | static void tty_port_destructor(struct kref *kref) |
| 255 | { |
| 256 | struct tty_port *port = container_of(kref, struct tty_port, kref); |
Peter Hurley | e3bfea2 | 2013-09-18 20:42:39 -0400 | [diff] [blame] | 257 | |
| 258 | /* check if last port ref was dropped before tty release */ |
| 259 | if (WARN_ON(port->itty)) |
| 260 | return; |
Alan Cox | 568aafc | 2009-11-30 13:17:14 +0000 | [diff] [blame] | 261 | if (port->xmit_buf) |
| 262 | free_page((unsigned long)port->xmit_buf); |
Jiri Slaby | de274bf | 2012-11-15 09:49:54 +0100 | [diff] [blame] | 263 | tty_port_destroy(port); |
Jiri Slaby | 81c7983 | 2012-11-15 09:49:49 +0100 | [diff] [blame] | 264 | if (port->ops && port->ops->destruct) |
Alan Cox | 568aafc | 2009-11-30 13:17:14 +0000 | [diff] [blame] | 265 | port->ops->destruct(port); |
| 266 | else |
| 267 | kfree(port); |
| 268 | } |
| 269 | |
| 270 | void tty_port_put(struct tty_port *port) |
| 271 | { |
| 272 | if (port) |
| 273 | kref_put(&port->kref, tty_port_destructor); |
| 274 | } |
| 275 | EXPORT_SYMBOL(tty_port_put); |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 276 | |
Alan Cox | 4a90f09 | 2008-10-13 10:39:46 +0100 | [diff] [blame] | 277 | /** |
| 278 | * tty_port_tty_get - get a tty reference |
| 279 | * @port: tty port |
| 280 | * |
| 281 | * Return a refcount protected tty instance or NULL if the port is not |
| 282 | * associated with a tty (eg due to close or hangup) |
| 283 | */ |
Alan Cox | 4a90f09 | 2008-10-13 10:39:46 +0100 | [diff] [blame] | 284 | struct tty_struct *tty_port_tty_get(struct tty_port *port) |
| 285 | { |
| 286 | unsigned long flags; |
| 287 | struct tty_struct *tty; |
| 288 | |
| 289 | spin_lock_irqsave(&port->lock, flags); |
| 290 | tty = tty_kref_get(port->tty); |
| 291 | spin_unlock_irqrestore(&port->lock, flags); |
| 292 | return tty; |
| 293 | } |
| 294 | EXPORT_SYMBOL(tty_port_tty_get); |
| 295 | |
| 296 | /** |
| 297 | * tty_port_tty_set - set the tty of a port |
| 298 | * @port: tty port |
| 299 | * @tty: the tty |
| 300 | * |
| 301 | * Associate the port and tty pair. Manages any internal refcounts. |
| 302 | * Pass NULL to deassociate a port |
| 303 | */ |
Alan Cox | 4a90f09 | 2008-10-13 10:39:46 +0100 | [diff] [blame] | 304 | void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) |
| 305 | { |
| 306 | unsigned long flags; |
| 307 | |
| 308 | spin_lock_irqsave(&port->lock, flags); |
Markus Elfring | a211b1a | 2014-11-21 13:42:29 +0100 | [diff] [blame] | 309 | tty_kref_put(port->tty); |
Alan Cox | cb4bca3 | 2008-10-21 13:47:44 +0100 | [diff] [blame] | 310 | port->tty = tty_kref_get(tty); |
Alan Cox | 4a90f09 | 2008-10-13 10:39:46 +0100 | [diff] [blame] | 311 | spin_unlock_irqrestore(&port->lock, flags); |
| 312 | } |
| 313 | EXPORT_SYMBOL(tty_port_tty_set); |
Alan Cox | 31f3593 | 2009-01-02 13:45:05 +0000 | [diff] [blame] | 314 | |
Johan Hovold | 957daca | 2013-03-07 15:55:51 +0100 | [diff] [blame] | 315 | static void tty_port_shutdown(struct tty_port *port, struct tty_struct *tty) |
Alan Cox | 7ca0ff9 | 2009-09-19 13:13:20 -0700 | [diff] [blame] | 316 | { |
Alan Cox | 64bc397 | 2009-10-06 16:06:11 +0100 | [diff] [blame] | 317 | mutex_lock(&port->mutex); |
Johan Hovold | 8bde965 | 2013-03-07 15:55:48 +0100 | [diff] [blame] | 318 | if (port->console) |
| 319 | goto out; |
| 320 | |
Peter Hurley | d41861c | 2016-04-09 17:53:25 -0700 | [diff] [blame] | 321 | if (tty_port_initialized(port)) { |
| 322 | tty_port_set_initialized(port, 0); |
Johan Hovold | 957daca | 2013-03-07 15:55:51 +0100 | [diff] [blame] | 323 | /* |
| 324 | * Drop DTR/RTS if HUPCL is set. This causes any attached |
| 325 | * modem to hang up the line. |
| 326 | */ |
| 327 | if (tty && C_HUPCL(tty)) |
| 328 | tty_port_lower_dtr_rts(port); |
| 329 | |
Johan Hovold | 0d3cb6f | 2019-04-03 09:40:53 +0200 | [diff] [blame] | 330 | if (port->ops->shutdown) |
Alan Cox | 7ca0ff9 | 2009-09-19 13:13:20 -0700 | [diff] [blame] | 331 | port->ops->shutdown(port); |
Johan Hovold | 8bde965 | 2013-03-07 15:55:48 +0100 | [diff] [blame] | 332 | } |
| 333 | out: |
Alan Cox | 64bc397 | 2009-10-06 16:06:11 +0100 | [diff] [blame] | 334 | mutex_unlock(&port->mutex); |
Alan Cox | 7ca0ff9 | 2009-09-19 13:13:20 -0700 | [diff] [blame] | 335 | } |
| 336 | |
Alan Cox | 31f3593 | 2009-01-02 13:45:05 +0000 | [diff] [blame] | 337 | /** |
Alan Cox | 3e61696 | 2009-01-02 13:45:26 +0000 | [diff] [blame] | 338 | * tty_port_hangup - hangup helper |
| 339 | * @port: tty port |
| 340 | * |
| 341 | * Perform port level tty hangup flag and count changes. Drop the tty |
| 342 | * reference. |
Peter Hurley | 9c9928b | 2014-06-16 09:17:02 -0400 | [diff] [blame] | 343 | * |
| 344 | * Caller holds tty lock. |
Alan Cox | 3e61696 | 2009-01-02 13:45:26 +0000 | [diff] [blame] | 345 | */ |
Alan Cox | 3e61696 | 2009-01-02 13:45:26 +0000 | [diff] [blame] | 346 | void tty_port_hangup(struct tty_port *port) |
| 347 | { |
Johan Hovold | 957daca | 2013-03-07 15:55:51 +0100 | [diff] [blame] | 348 | struct tty_struct *tty; |
Alan Cox | 3e61696 | 2009-01-02 13:45:26 +0000 | [diff] [blame] | 349 | unsigned long flags; |
| 350 | |
| 351 | spin_lock_irqsave(&port->lock, flags); |
| 352 | port->count = 0; |
Johan Hovold | 957daca | 2013-03-07 15:55:51 +0100 | [diff] [blame] | 353 | tty = port->tty; |
| 354 | if (tty) |
| 355 | set_bit(TTY_IO_ERROR, &tty->flags); |
Alan Cox | 3e61696 | 2009-01-02 13:45:26 +0000 | [diff] [blame] | 356 | port->tty = NULL; |
| 357 | spin_unlock_irqrestore(&port->lock, flags); |
Peter Hurley | 807c8d81 | 2016-04-09 17:53:22 -0700 | [diff] [blame] | 358 | tty_port_set_active(port, 0); |
Johan Hovold | 957daca | 2013-03-07 15:55:51 +0100 | [diff] [blame] | 359 | tty_port_shutdown(port, tty); |
| 360 | tty_kref_put(tty); |
Alan Cox | 3e61696 | 2009-01-02 13:45:26 +0000 | [diff] [blame] | 361 | wake_up_interruptible(&port->open_wait); |
Alan Cox | bdc04e3 | 2009-09-19 13:13:31 -0700 | [diff] [blame] | 362 | wake_up_interruptible(&port->delta_msr_wait); |
Alan Cox | 3e61696 | 2009-01-02 13:45:26 +0000 | [diff] [blame] | 363 | } |
| 364 | EXPORT_SYMBOL(tty_port_hangup); |
| 365 | |
| 366 | /** |
Jiri Slaby | aa27a09 | 2013-03-07 13:12:30 +0100 | [diff] [blame] | 367 | * tty_port_tty_hangup - helper to hang up a tty |
| 368 | * |
| 369 | * @port: tty port |
| 370 | * @check_clocal: hang only ttys with CLOCAL unset? |
| 371 | */ |
| 372 | void tty_port_tty_hangup(struct tty_port *port, bool check_clocal) |
| 373 | { |
| 374 | struct tty_struct *tty = tty_port_tty_get(port); |
| 375 | |
Gianluca Anzolin | 1d9e689 | 2013-07-25 07:26:16 +0200 | [diff] [blame] | 376 | if (tty && (!check_clocal || !C_CLOCAL(tty))) |
Jiri Slaby | aa27a09 | 2013-03-07 13:12:30 +0100 | [diff] [blame] | 377 | tty_hangup(tty); |
Gianluca Anzolin | 1d9e689 | 2013-07-25 07:26:16 +0200 | [diff] [blame] | 378 | tty_kref_put(tty); |
Jiri Slaby | aa27a09 | 2013-03-07 13:12:30 +0100 | [diff] [blame] | 379 | } |
| 380 | EXPORT_SYMBOL_GPL(tty_port_tty_hangup); |
| 381 | |
| 382 | /** |
Jiri Slaby | 6aad04f | 2013-03-07 13:12:29 +0100 | [diff] [blame] | 383 | * tty_port_tty_wakeup - helper to wake up a tty |
| 384 | * |
| 385 | * @port: tty port |
| 386 | */ |
| 387 | void tty_port_tty_wakeup(struct tty_port *port) |
| 388 | { |
Rob Herring | c3485ee | 2017-02-02 13:48:05 -0600 | [diff] [blame] | 389 | port->client_ops->write_wakeup(port); |
Jiri Slaby | 6aad04f | 2013-03-07 13:12:29 +0100 | [diff] [blame] | 390 | } |
| 391 | EXPORT_SYMBOL_GPL(tty_port_tty_wakeup); |
| 392 | |
| 393 | /** |
Alan Cox | 31f3593 | 2009-01-02 13:45:05 +0000 | [diff] [blame] | 394 | * tty_port_carrier_raised - carrier raised check |
| 395 | * @port: tty port |
| 396 | * |
| 397 | * Wrapper for the carrier detect logic. For the moment this is used |
| 398 | * to hide some internal details. This will eventually become entirely |
| 399 | * internal to the tty port. |
| 400 | */ |
Alan Cox | 31f3593 | 2009-01-02 13:45:05 +0000 | [diff] [blame] | 401 | int tty_port_carrier_raised(struct tty_port *port) |
| 402 | { |
Johan Hovold | 0d3cb6f | 2019-04-03 09:40:53 +0200 | [diff] [blame] | 403 | if (port->ops->carrier_raised == NULL) |
Alan Cox | 31f3593 | 2009-01-02 13:45:05 +0000 | [diff] [blame] | 404 | return 1; |
| 405 | return port->ops->carrier_raised(port); |
| 406 | } |
| 407 | EXPORT_SYMBOL(tty_port_carrier_raised); |
Alan Cox | 5d951fb | 2009-01-02 13:45:19 +0000 | [diff] [blame] | 408 | |
| 409 | /** |
Alan Cox | fcc8ac1 | 2009-06-11 12:24:17 +0100 | [diff] [blame] | 410 | * tty_port_raise_dtr_rts - Raise DTR/RTS |
Alan Cox | 5d951fb | 2009-01-02 13:45:19 +0000 | [diff] [blame] | 411 | * @port: tty port |
| 412 | * |
| 413 | * Wrapper for the DTR/RTS raise logic. For the moment this is used |
| 414 | * to hide some internal details. This will eventually become entirely |
| 415 | * internal to the tty port. |
| 416 | */ |
Alan Cox | 5d951fb | 2009-01-02 13:45:19 +0000 | [diff] [blame] | 417 | void tty_port_raise_dtr_rts(struct tty_port *port) |
| 418 | { |
Johan Hovold | 0d3cb6f | 2019-04-03 09:40:53 +0200 | [diff] [blame] | 419 | if (port->ops->dtr_rts) |
Alan Cox | fcc8ac1 | 2009-06-11 12:24:17 +0100 | [diff] [blame] | 420 | port->ops->dtr_rts(port, 1); |
Alan Cox | 5d951fb | 2009-01-02 13:45:19 +0000 | [diff] [blame] | 421 | } |
| 422 | EXPORT_SYMBOL(tty_port_raise_dtr_rts); |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 423 | |
| 424 | /** |
Alan Cox | fcc8ac1 | 2009-06-11 12:24:17 +0100 | [diff] [blame] | 425 | * tty_port_lower_dtr_rts - Lower DTR/RTS |
| 426 | * @port: tty port |
| 427 | * |
| 428 | * Wrapper for the DTR/RTS raise logic. For the moment this is used |
| 429 | * to hide some internal details. This will eventually become entirely |
| 430 | * internal to the tty port. |
| 431 | */ |
Alan Cox | fcc8ac1 | 2009-06-11 12:24:17 +0100 | [diff] [blame] | 432 | void tty_port_lower_dtr_rts(struct tty_port *port) |
| 433 | { |
Johan Hovold | 0d3cb6f | 2019-04-03 09:40:53 +0200 | [diff] [blame] | 434 | if (port->ops->dtr_rts) |
Alan Cox | fcc8ac1 | 2009-06-11 12:24:17 +0100 | [diff] [blame] | 435 | port->ops->dtr_rts(port, 0); |
| 436 | } |
| 437 | EXPORT_SYMBOL(tty_port_lower_dtr_rts); |
| 438 | |
| 439 | /** |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 440 | * tty_port_block_til_ready - Waiting logic for tty open |
| 441 | * @port: the tty port being opened |
| 442 | * @tty: the tty device being bound |
Alan Cox | ed3f0af | 2017-01-16 16:54:29 -0600 | [diff] [blame] | 443 | * @filp: the file pointer of the opener or NULL |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 444 | * |
| 445 | * Implement the core POSIX/SuS tty behaviour when opening a tty device. |
| 446 | * Handles: |
| 447 | * - hangup (both before and during) |
| 448 | * - non blocking open |
| 449 | * - rts/dtr/dcd |
| 450 | * - signals |
| 451 | * - port flags and counts |
| 452 | * |
| 453 | * The passed tty_port must implement the carrier_raised method if it can |
Alan Cox | fcc8ac1 | 2009-06-11 12:24:17 +0100 | [diff] [blame] | 454 | * do carrier detect and the dtr_rts method if it supports software |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 455 | * management of these lines. Note that the dtr/rts raise is done each |
| 456 | * iteration as a hangup may have previously dropped them while we wait. |
Peter Hurley | c590f6b6 | 2014-06-16 09:17:01 -0400 | [diff] [blame] | 457 | * |
| 458 | * Caller holds tty lock. |
| 459 | * |
| 460 | * NB: May drop and reacquire tty lock when blocking, so tty and tty_port |
| 461 | * may have changed state (eg., may have been hung up). |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 462 | */ |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 463 | int tty_port_block_til_ready(struct tty_port *port, |
| 464 | struct tty_struct *tty, struct file *filp) |
| 465 | { |
| 466 | int do_clocal = 0, retval; |
| 467 | unsigned long flags; |
Jiri Slaby | 6af9a43 | 2009-06-24 18:35:05 +0100 | [diff] [blame] | 468 | DEFINE_WAIT(wait); |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 469 | |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 470 | /* if non-blocking mode is set we can pass directly to open unless |
Xiaofei Tan | 1df9264 | 2021-05-12 17:26:25 +0800 | [diff] [blame] | 471 | * the port has just hung up or is in another error state. |
| 472 | */ |
Peter Hurley | 18900ca | 2016-04-09 17:06:48 -0700 | [diff] [blame] | 473 | if (tty_io_error(tty)) { |
Peter Hurley | 807c8d81 | 2016-04-09 17:53:22 -0700 | [diff] [blame] | 474 | tty_port_set_active(port, 1); |
Alan Cox | 8627b96 | 2009-11-18 14:12:58 +0000 | [diff] [blame] | 475 | return 0; |
| 476 | } |
Alan Cox | ed3f0af | 2017-01-16 16:54:29 -0600 | [diff] [blame] | 477 | if (filp == NULL || (filp->f_flags & O_NONBLOCK)) { |
Alan Cox | 4175f3e | 2009-10-28 21:12:32 +0100 | [diff] [blame] | 478 | /* Indicate we are open */ |
Peter Hurley | 9db276f | 2016-01-10 20:36:15 -0800 | [diff] [blame] | 479 | if (C_BAUD(tty)) |
Alan Cox | 4175f3e | 2009-10-28 21:12:32 +0100 | [diff] [blame] | 480 | tty_port_raise_dtr_rts(port); |
Peter Hurley | 807c8d81 | 2016-04-09 17:53:22 -0700 | [diff] [blame] | 481 | tty_port_set_active(port, 1); |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 482 | return 0; |
| 483 | } |
| 484 | |
| 485 | if (C_CLOCAL(tty)) |
| 486 | do_clocal = 1; |
| 487 | |
| 488 | /* Block waiting until we can proceed. We may need to wait for the |
Xiaofei Tan | 1df9264 | 2021-05-12 17:26:25 +0800 | [diff] [blame] | 489 | * carrier, but we must also wait for any close that is in progress |
| 490 | * before the next open may complete. |
| 491 | */ |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 492 | |
| 493 | retval = 0; |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 494 | |
| 495 | /* The port lock protects the port counts */ |
| 496 | spin_lock_irqsave(&port->lock, flags); |
Peter Hurley | e359a4e | 2014-06-16 09:17:06 -0400 | [diff] [blame] | 497 | port->count--; |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 498 | port->blocked_open++; |
| 499 | spin_unlock_irqrestore(&port->lock, flags); |
| 500 | |
| 501 | while (1) { |
| 502 | /* Indicate we are open */ |
Peter Hurley | d41861c | 2016-04-09 17:53:25 -0700 | [diff] [blame] | 503 | if (C_BAUD(tty) && tty_port_initialized(port)) |
Alan Cox | 7834909 | 2009-01-02 13:46:43 +0000 | [diff] [blame] | 504 | tty_port_raise_dtr_rts(port); |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 505 | |
Jiri Slaby | 3e3b5c0 | 2009-06-11 14:33:37 +0100 | [diff] [blame] | 506 | prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE); |
Alan Cox | d774a56 | 2009-10-06 16:06:21 +0100 | [diff] [blame] | 507 | /* Check for a hangup or uninitialised port. |
Xiaofei Tan | 1df9264 | 2021-05-12 17:26:25 +0800 | [diff] [blame] | 508 | * Return accordingly. |
| 509 | */ |
Peter Hurley | d41861c | 2016-04-09 17:53:25 -0700 | [diff] [blame] | 510 | if (tty_hung_up_p(filp) || !tty_port_initialized(port)) { |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 511 | if (port->flags & ASYNC_HUP_NOTIFY) |
| 512 | retval = -EAGAIN; |
| 513 | else |
| 514 | retval = -ERESTARTSYS; |
| 515 | break; |
| 516 | } |
Jiri Slaby | 0eee50a | 2012-01-12 22:55:15 +0100 | [diff] [blame] | 517 | /* |
| 518 | * Probe the carrier. For devices with no carrier detect |
| 519 | * tty_port_carrier_raised will always return true. |
| 520 | * Never ask drivers if CLOCAL is set, this causes troubles |
| 521 | * on some hardware. |
| 522 | */ |
Peter Hurley | fef062c | 2015-10-10 16:00:52 -0400 | [diff] [blame] | 523 | if (do_clocal || tty_port_carrier_raised(port)) |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 524 | break; |
| 525 | if (signal_pending(current)) { |
| 526 | retval = -ERESTARTSYS; |
| 527 | break; |
| 528 | } |
Alan Cox | 89c8d91 | 2012-08-08 16:30:13 +0100 | [diff] [blame] | 529 | tty_unlock(tty); |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 530 | schedule(); |
Alan Cox | 89c8d91 | 2012-08-08 16:30:13 +0100 | [diff] [blame] | 531 | tty_lock(tty); |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 532 | } |
Jiri Slaby | 3e3b5c0 | 2009-06-11 14:33:37 +0100 | [diff] [blame] | 533 | finish_wait(&port->open_wait, &wait); |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 534 | |
| 535 | /* Update counts. A parallel hangup will have set count to zero and |
Xiaofei Tan | 1df9264 | 2021-05-12 17:26:25 +0800 | [diff] [blame] | 536 | * we must not mess that up further. |
| 537 | */ |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 538 | spin_lock_irqsave(&port->lock, flags); |
| 539 | if (!tty_hung_up_p(filp)) |
| 540 | port->count++; |
| 541 | port->blocked_open--; |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 542 | spin_unlock_irqrestore(&port->lock, flags); |
Peter Hurley | 807c8d81 | 2016-04-09 17:53:22 -0700 | [diff] [blame] | 543 | if (retval == 0) |
| 544 | tty_port_set_active(port, 1); |
Alan Cox | ecc2e05 | 2009-07-17 16:17:26 +0100 | [diff] [blame] | 545 | return retval; |
Alan Cox | 36c621d | 2009-01-02 13:46:10 +0000 | [diff] [blame] | 546 | } |
| 547 | EXPORT_SYMBOL(tty_port_block_til_ready); |
| 548 | |
Johan Hovold | b74414f | 2013-03-07 15:55:52 +0100 | [diff] [blame] | 549 | static void tty_port_drain_delay(struct tty_port *port, struct tty_struct *tty) |
| 550 | { |
| 551 | unsigned int bps = tty_get_baud_rate(tty); |
| 552 | long timeout; |
| 553 | |
| 554 | if (bps > 1200) { |
| 555 | timeout = (HZ * 10 * port->drain_delay) / bps; |
| 556 | timeout = max_t(long, timeout, HZ / 10); |
| 557 | } else { |
| 558 | timeout = 2 * HZ; |
| 559 | } |
| 560 | schedule_timeout_interruptible(timeout); |
| 561 | } |
| 562 | |
Peter Hurley | 79c1faa | 2015-10-10 16:00:51 -0400 | [diff] [blame] | 563 | /* Caller holds tty lock. */ |
Alan Cox | d774a56 | 2009-10-06 16:06:21 +0100 | [diff] [blame] | 564 | int tty_port_close_start(struct tty_port *port, |
| 565 | struct tty_struct *tty, struct file *filp) |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 566 | { |
| 567 | unsigned long flags; |
| 568 | |
Peter Hurley | 633caba8 | 2014-11-05 12:40:03 -0500 | [diff] [blame] | 569 | if (tty_hung_up_p(filp)) |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 570 | return 0; |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 571 | |
Peter Hurley | 633caba8 | 2014-11-05 12:40:03 -0500 | [diff] [blame] | 572 | spin_lock_irqsave(&port->lock, flags); |
Alan Cox | d774a56 | 2009-10-06 16:06:21 +0100 | [diff] [blame] | 573 | if (tty->count == 1 && port->count != 1) { |
Peter Hurley | 339f36b | 2015-11-08 13:01:13 -0500 | [diff] [blame] | 574 | tty_warn(tty, "%s: tty->count = 1 port count = %d\n", __func__, |
| 575 | port->count); |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 576 | port->count = 1; |
| 577 | } |
| 578 | if (--port->count < 0) { |
Peter Hurley | 339f36b | 2015-11-08 13:01:13 -0500 | [diff] [blame] | 579 | tty_warn(tty, "%s: bad port count (%d)\n", __func__, |
| 580 | port->count); |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 581 | port->count = 0; |
| 582 | } |
| 583 | |
| 584 | if (port->count) { |
| 585 | spin_unlock_irqrestore(&port->lock, flags); |
| 586 | return 0; |
| 587 | } |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 588 | spin_unlock_irqrestore(&port->lock, flags); |
Johan Hovold | 0b2588c | 2013-03-07 15:55:53 +0100 | [diff] [blame] | 589 | |
Peter Hurley | ddc7b75 | 2014-06-16 09:17:03 -0400 | [diff] [blame] | 590 | tty->closing = 1; |
| 591 | |
Peter Hurley | d41861c | 2016-04-09 17:53:25 -0700 | [diff] [blame] | 592 | if (tty_port_initialized(port)) { |
Johan Hovold | 0b2588c | 2013-03-07 15:55:53 +0100 | [diff] [blame] | 593 | /* Don't block on a stalled port, just pull the chain */ |
Jiri Slaby | 6e94dbc | 2021-05-05 11:19:05 +0200 | [diff] [blame] | 594 | if (tty->flow.tco_stopped) |
Johan Hovold | 0b2588c | 2013-03-07 15:55:53 +0100 | [diff] [blame] | 595 | tty_driver_flush_buffer(tty); |
| 596 | if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) |
Peter Hurley | 79c1faa | 2015-10-10 16:00:51 -0400 | [diff] [blame] | 597 | tty_wait_until_sent(tty, port->closing_wait); |
Johan Hovold | 0b2588c | 2013-03-07 15:55:53 +0100 | [diff] [blame] | 598 | if (port->drain_delay) |
| 599 | tty_port_drain_delay(port, tty); |
| 600 | } |
Alan Cox | e707c35 | 2009-11-05 13:27:57 +0000 | [diff] [blame] | 601 | /* Flush the ldisc buffering */ |
| 602 | tty_ldisc_flush(tty); |
| 603 | |
Peter Hurley | 469d6d0 | 2013-09-18 20:47:06 -0400 | [diff] [blame] | 604 | /* Report to caller this is the last port reference */ |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 605 | return 1; |
| 606 | } |
| 607 | EXPORT_SYMBOL(tty_port_close_start); |
| 608 | |
Peter Hurley | 0733db91 | 2014-06-16 09:16:59 -0400 | [diff] [blame] | 609 | /* Caller holds tty lock */ |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 610 | void tty_port_close_end(struct tty_port *port, struct tty_struct *tty) |
| 611 | { |
| 612 | unsigned long flags; |
| 613 | |
Peter Hurley | 3f40f5b | 2014-11-05 12:40:05 -0500 | [diff] [blame] | 614 | tty_ldisc_flush(tty); |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 615 | tty->closing = 0; |
| 616 | |
Peter Hurley | ddc7b75 | 2014-06-16 09:17:03 -0400 | [diff] [blame] | 617 | spin_lock_irqsave(&port->lock, flags); |
| 618 | |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 619 | if (port->blocked_open) { |
| 620 | spin_unlock_irqrestore(&port->lock, flags); |
Peter Hurley | 5823323e | 2016-01-10 20:36:14 -0800 | [diff] [blame] | 621 | if (port->close_delay) |
| 622 | msleep_interruptible(jiffies_to_msecs(port->close_delay)); |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 623 | spin_lock_irqsave(&port->lock, flags); |
| 624 | wake_up_interruptible(&port->open_wait); |
| 625 | } |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 626 | spin_unlock_irqrestore(&port->lock, flags); |
Peter Hurley | 807c8d81 | 2016-04-09 17:53:22 -0700 | [diff] [blame] | 627 | tty_port_set_active(port, 0); |
Alan Cox | a661499 | 2009-01-02 13:46:50 +0000 | [diff] [blame] | 628 | } |
| 629 | EXPORT_SYMBOL(tty_port_close_end); |
Alan Cox | 7ca0ff9 | 2009-09-19 13:13:20 -0700 | [diff] [blame] | 630 | |
Lee Jones | 1b1deb4 | 2020-11-04 19:35:19 +0000 | [diff] [blame] | 631 | /* |
Peter Hurley | 0733db91 | 2014-06-16 09:16:59 -0400 | [diff] [blame] | 632 | * tty_port_close |
| 633 | * |
| 634 | * Caller holds tty lock |
Peter Hurley | 0733db91 | 2014-06-16 09:16:59 -0400 | [diff] [blame] | 635 | */ |
Alan Cox | 7ca0ff9 | 2009-09-19 13:13:20 -0700 | [diff] [blame] | 636 | void tty_port_close(struct tty_port *port, struct tty_struct *tty, |
| 637 | struct file *filp) |
| 638 | { |
| 639 | if (tty_port_close_start(port, tty, filp) == 0) |
| 640 | return; |
Johan Hovold | 957daca | 2013-03-07 15:55:51 +0100 | [diff] [blame] | 641 | tty_port_shutdown(port, tty); |
Chanho Park | 2a48602 | 2018-11-22 18:23:47 +0900 | [diff] [blame] | 642 | if (!port->console) |
| 643 | set_bit(TTY_IO_ERROR, &tty->flags); |
Alan Cox | 7ca0ff9 | 2009-09-19 13:13:20 -0700 | [diff] [blame] | 644 | tty_port_close_end(port, tty); |
| 645 | tty_port_tty_set(port, NULL); |
| 646 | } |
| 647 | EXPORT_SYMBOL(tty_port_close); |
Alan Cox | 64bc397 | 2009-10-06 16:06:11 +0100 | [diff] [blame] | 648 | |
Jiri Slaby | 72a33bf | 2012-08-07 21:47:49 +0200 | [diff] [blame] | 649 | /** |
| 650 | * tty_port_install - generic tty->ops->install handler |
| 651 | * @port: tty_port of the device |
| 652 | * @driver: tty_driver for this device |
| 653 | * @tty: tty to be installed |
| 654 | * |
| 655 | * It is the same as tty_standard_install except the provided @port is linked |
| 656 | * to a concrete tty specified by @tty. Use this or tty_port_register_device |
| 657 | * (or both). Call tty_port_link_device as a last resort. |
| 658 | */ |
Jiri Slaby | 695586c | 2012-06-04 13:35:32 +0200 | [diff] [blame] | 659 | int tty_port_install(struct tty_port *port, struct tty_driver *driver, |
| 660 | struct tty_struct *tty) |
| 661 | { |
| 662 | tty->port = port; |
| 663 | return tty_standard_install(driver, tty); |
| 664 | } |
| 665 | EXPORT_SYMBOL_GPL(tty_port_install); |
| 666 | |
Lee Jones | 1b1deb4 | 2020-11-04 19:35:19 +0000 | [diff] [blame] | 667 | /* |
Peter Hurley | addd467 | 2014-06-16 09:17:00 -0400 | [diff] [blame] | 668 | * tty_port_open |
| 669 | * |
| 670 | * Caller holds tty lock. |
| 671 | * |
| 672 | * NB: may drop and reacquire tty lock (in tty_port_block_til_ready()) so |
| 673 | * tty and tty_port may have changed state (eg., may be hung up now) |
| 674 | */ |
Alan Cox | 64bc397 | 2009-10-06 16:06:11 +0100 | [diff] [blame] | 675 | int tty_port_open(struct tty_port *port, struct tty_struct *tty, |
Alan Cox | d774a56 | 2009-10-06 16:06:21 +0100 | [diff] [blame] | 676 | struct file *filp) |
Alan Cox | 64bc397 | 2009-10-06 16:06:11 +0100 | [diff] [blame] | 677 | { |
| 678 | spin_lock_irq(&port->lock); |
Peter Hurley | e359a4e | 2014-06-16 09:17:06 -0400 | [diff] [blame] | 679 | ++port->count; |
Alan Cox | 64bc397 | 2009-10-06 16:06:11 +0100 | [diff] [blame] | 680 | spin_unlock_irq(&port->lock); |
| 681 | tty_port_tty_set(port, tty); |
| 682 | |
| 683 | /* |
| 684 | * Do the device-specific open only if the hardware isn't |
| 685 | * already initialized. Serialize open and shutdown using the |
| 686 | * port mutex. |
| 687 | */ |
| 688 | |
| 689 | mutex_lock(&port->mutex); |
| 690 | |
Peter Hurley | d41861c | 2016-04-09 17:53:25 -0700 | [diff] [blame] | 691 | if (!tty_port_initialized(port)) { |
Alan Cox | a9a37ec | 2009-11-30 13:16:57 +0000 | [diff] [blame] | 692 | clear_bit(TTY_IO_ERROR, &tty->flags); |
Johan Hovold | 0d3cb6f | 2019-04-03 09:40:53 +0200 | [diff] [blame] | 693 | if (port->ops->activate) { |
Alan Cox | 64bc397 | 2009-10-06 16:06:11 +0100 | [diff] [blame] | 694 | int retval = port->ops->activate(port, tty); |
Xiaofei Tan | 54ad59a | 2021-05-12 17:26:24 +0800 | [diff] [blame] | 695 | |
Alan Cox | 64bc397 | 2009-10-06 16:06:11 +0100 | [diff] [blame] | 696 | if (retval) { |
Alan Cox | d774a56 | 2009-10-06 16:06:21 +0100 | [diff] [blame] | 697 | mutex_unlock(&port->mutex); |
| 698 | return retval; |
| 699 | } |
| 700 | } |
Peter Hurley | d41861c | 2016-04-09 17:53:25 -0700 | [diff] [blame] | 701 | tty_port_set_initialized(port, 1); |
Alan Cox | 64bc397 | 2009-10-06 16:06:11 +0100 | [diff] [blame] | 702 | } |
| 703 | mutex_unlock(&port->mutex); |
| 704 | return tty_port_block_til_ready(port, tty, filp); |
| 705 | } |
Alan Cox | 64bc397 | 2009-10-06 16:06:11 +0100 | [diff] [blame] | 706 | EXPORT_SYMBOL(tty_port_open); |