1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
6 #include <linux/slab.h>
8 #include <linux/tty_flip.h>
13 #ifdef CONFIG_NOCONFIG_CHAN
14 static void *not_configged_init(char *str, int device,
15 const struct chan_opts *opts)
17 printk(KERN_ERR "Using a channel type which is configured out of "
22 static int not_configged_open(int input, int output, int primary, void *data,
25 printk(KERN_ERR "Using a channel type which is configured out of "
30 static void not_configged_close(int fd, void *data)
32 printk(KERN_ERR "Using a channel type which is configured out of "
36 static int not_configged_read(int fd, char *c_out, void *data)
38 printk(KERN_ERR "Using a channel type which is configured out of "
43 static int not_configged_write(int fd, const char *buf, int len, void *data)
45 printk(KERN_ERR "Using a channel type which is configured out of "
50 static int not_configged_console_write(int fd, const char *buf, int len)
52 printk(KERN_ERR "Using a channel type which is configured out of "
57 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
60 printk(KERN_ERR "Using a channel type which is configured out of "
65 static void not_configged_free(void *data)
67 printk(KERN_ERR "Using a channel type which is configured out of "
71 static const struct chan_ops not_configged_ops = {
72 .init = not_configged_init,
73 .open = not_configged_open,
74 .close = not_configged_close,
75 .read = not_configged_read,
76 .write = not_configged_write,
77 .console_write = not_configged_console_write,
78 .window_size = not_configged_window_size,
79 .free = not_configged_free,
82 #endif /* CONFIG_NOCONFIG_CHAN */
84 static int open_one_chan(struct chan *chan)
91 if (chan->ops->open == NULL)
93 else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
94 chan->data, &chan->dev);
98 err = os_set_fd_block(fd, 0);
100 (*chan->ops->close)(fd, chan->data);
110 static int open_chan(struct list_head *chans)
112 struct list_head *ele;
116 list_for_each(ele, chans) {
117 chan = list_entry(ele, struct chan, list);
118 ret = open_one_chan(chan);
125 void chan_enable_winch(struct chan *chan, struct tty_port *port)
127 if (chan && chan->primary && chan->ops->winch)
128 register_winch(chan->fd, port);
131 static void line_timer_cb(struct work_struct *work)
133 struct line *line = container_of(work, struct line, task.work);
135 if (!line->throttled)
136 chan_interrupt(line, line->driver->read_irq);
139 int enable_chan(struct line *line)
141 struct list_head *ele;
145 INIT_DELAYED_WORK(&line->task, line_timer_cb);
147 list_for_each(ele, &line->chan_list) {
148 chan = list_entry(ele, struct chan, list);
149 err = open_one_chan(chan);
159 err = line_setup_irq(chan->fd, chan->input, chan->output, line,
174 /* Items are added in IRQ context, when free_irq can't be called, and
175 * removed in process context, when it can.
176 * This handles interrupt sources which disappear, and which need to
177 * be permanently disabled. This is discovered in IRQ context, but
178 * the freeing of the IRQ must be done later.
180 static DEFINE_SPINLOCK(irqs_to_free_lock);
181 static LIST_HEAD(irqs_to_free);
187 struct list_head *ele;
190 spin_lock_irqsave(&irqs_to_free_lock, flags);
191 list_splice_init(&irqs_to_free, &list);
192 spin_unlock_irqrestore(&irqs_to_free_lock, flags);
194 list_for_each(ele, &list) {
195 chan = list_entry(ele, struct chan, free_list);
197 if (chan->input && chan->enabled)
198 um_free_irq(chan->line->driver->read_irq, chan);
199 if (chan->output && chan->enabled)
200 um_free_irq(chan->line->driver->write_irq, chan);
205 static void close_one_chan(struct chan *chan, int delay_free_irq)
212 if (delay_free_irq) {
213 spin_lock_irqsave(&irqs_to_free_lock, flags);
214 list_add(&chan->free_list, &irqs_to_free);
215 spin_unlock_irqrestore(&irqs_to_free_lock, flags);
217 if (chan->input && chan->enabled)
218 um_free_irq(chan->line->driver->read_irq, chan);
219 if (chan->output && chan->enabled)
220 um_free_irq(chan->line->driver->write_irq, chan);
223 if (chan->ops->close != NULL)
224 (*chan->ops->close)(chan->fd, chan->data);
230 void close_chan(struct line *line)
234 /* Close in reverse order as open in case more than one of them
235 * refers to the same device and they save and restore that device's
236 * state. Then, the first one opened will have the original state,
237 * so it must be the last closed.
239 list_for_each_entry_reverse(chan, &line->chan_list, list) {
240 close_one_chan(chan, 0);
244 void deactivate_chan(struct chan *chan, int irq)
246 if (chan && chan->enabled)
247 deactivate_fd(chan->fd, irq);
250 int write_chan(struct chan *chan, const char *buf, int len,
255 if (len == 0 || !chan || !chan->ops->write)
258 n = chan->ops->write(chan->fd, buf, len, chan->data);
265 int console_write_chan(struct chan *chan, const char *buf, int len)
269 if (!chan || !chan->ops->console_write)
272 n = chan->ops->console_write(chan->fd, buf, len);
278 int console_open_chan(struct line *line, struct console *co)
282 err = open_chan(&line->chan_list);
286 printk(KERN_INFO "Console initialized on /dev/%s%d\n", co->name,
291 int chan_window_size(struct line *line, unsigned short *rows_out,
292 unsigned short *cols_out)
296 chan = line->chan_in;
297 if (chan && chan->primary) {
298 if (chan->ops->window_size == NULL)
300 return chan->ops->window_size(chan->fd, chan->data,
303 chan = line->chan_out;
304 if (chan && chan->primary) {
305 if (chan->ops->window_size == NULL)
307 return chan->ops->window_size(chan->fd, chan->data,
313 static void free_one_chan(struct chan *chan)
315 list_del(&chan->list);
317 close_one_chan(chan, 0);
319 if (chan->ops->free != NULL)
320 (*chan->ops->free)(chan->data);
322 if (chan->primary && chan->output)
323 ignore_sigio_fd(chan->fd);
327 static void free_chan(struct list_head *chans)
329 struct list_head *ele, *next;
332 list_for_each_safe(ele, next, chans) {
333 chan = list_entry(ele, struct chan, list);
338 static int one_chan_config_string(struct chan *chan, char *str, int size,
344 CONFIG_CHUNK(str, size, n, "none", 1);
348 CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
350 if (chan->dev == NULL) {
351 CONFIG_CHUNK(str, size, n, "", 1);
355 CONFIG_CHUNK(str, size, n, ":", 0);
356 CONFIG_CHUNK(str, size, n, chan->dev, 0);
361 static int chan_pair_config_string(struct chan *in, struct chan *out,
362 char *str, int size, char **error_out)
366 n = one_chan_config_string(in, str, size, error_out);
371 CONFIG_CHUNK(str, size, n, "", 1);
375 CONFIG_CHUNK(str, size, n, ",", 1);
376 n = one_chan_config_string(out, str, size, error_out);
379 CONFIG_CHUNK(str, size, n, "", 1);
384 int chan_config_string(struct line *line, char *str, int size,
387 struct chan *in = line->chan_in, *out = line->chan_out;
389 if (in && !in->primary)
391 if (out && !out->primary)
394 return chan_pair_config_string(in, out, str, size, error_out);
399 const struct chan_ops *ops;
402 static const struct chan_type chan_table[] = {
405 #ifdef CONFIG_NULL_CHAN
406 { "null", &null_ops },
408 { "null", ¬_configged_ops },
411 #ifdef CONFIG_PORT_CHAN
412 { "port", &port_ops },
414 { "port", ¬_configged_ops },
417 #ifdef CONFIG_PTY_CHAN
421 { "pty", ¬_configged_ops },
422 { "pts", ¬_configged_ops },
425 #ifdef CONFIG_TTY_CHAN
428 { "tty", ¬_configged_ops },
431 #ifdef CONFIG_XTERM_CHAN
432 { "xterm", &xterm_ops },
434 { "xterm", ¬_configged_ops },
438 static struct chan *parse_chan(struct line *line, char *str, int device,
439 const struct chan_opts *opts, char **error_out)
441 const struct chan_type *entry;
442 const struct chan_ops *ops;
449 for(i = 0; i < ARRAY_SIZE(chan_table); i++) {
450 entry = &chan_table[i];
451 if (!strncmp(str, entry->key, strlen(entry->key))) {
453 str += strlen(entry->key);
458 *error_out = "No match for configured backends";
462 data = (*ops->init)(str, device, opts);
464 *error_out = "Configuration failed";
468 chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
470 *error_out = "Memory allocation failed";
473 *chan = ((struct chan) { .list = LIST_HEAD_INIT(chan->list),
475 LIST_HEAD_INIT(chan->free_list),
488 int parse_chan_pair(char *str, struct line *line, int device,
489 const struct chan_opts *opts, char **error_out)
491 struct list_head *chans = &line->chan_list;
495 if (!list_empty(chans)) {
496 line->chan_in = line->chan_out = NULL;
498 INIT_LIST_HEAD(chans);
504 out = strchr(str, ',');
509 new = parse_chan(line, in, device, opts, error_out);
514 list_add(&new->list, chans);
517 new = parse_chan(line, out, device, opts, error_out);
521 list_add(&new->list, chans);
523 line->chan_out = new;
526 new = parse_chan(line, str, device, opts, error_out);
530 list_add(&new->list, chans);
533 line->chan_in = line->chan_out = new;
538 void chan_interrupt(struct line *line, int irq)
540 struct tty_port *port = &line->port;
541 struct chan *chan = line->chan_in;
545 if (!chan || !chan->ops->read)
549 if (!tty_buffer_request_room(port, 1)) {
550 schedule_delayed_work(&line->task, 1);
553 err = chan->ops->read(chan->fd, &c, chan->data);
555 tty_insert_flip_char(port, c, TTY_NORMAL);
560 tty_port_tty_hangup(&line->port, false);
561 if (line->chan_out != chan)
562 close_one_chan(line->chan_out, 1);
564 close_one_chan(chan, 1);
569 tty_flip_buffer_push(port);