1 /* vcc.c: sun4v virtual channel concentrator
3 * Copyright (C) 2017 Oracle. All rights reserved.
6 #include <linux/delay.h>
7 #include <linux/interrupt.h>
8 #include <linux/module.h>
9 #include <linux/slab.h>
10 #include <linux/sysfs.h>
11 #include <linux/tty.h>
12 #include <linux/tty_flip.h>
16 #define DRV_MODULE_NAME "vcc"
17 #define DRV_MODULE_VERSION "1.1"
18 #define DRV_MODULE_RELDATE "July 1, 2017"
20 static char version[] =
21 DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")";
23 MODULE_DESCRIPTION("Sun LDOM virtual console concentrator driver");
24 MODULE_LICENSE("GPL");
25 MODULE_VERSION(DRV_MODULE_VERSION);
28 struct vio_driver_state vio;
32 struct tty_struct *tty; /* only populated while dev is open */
33 unsigned long index; /* index into the vcc_table */
40 /* This buffer is required to support the tty write_room interface
41 * and guarantee that any characters that the driver accepts will
42 * be eventually sent, either immediately or later.
45 struct vio_vcc buffer;
47 struct timer_list rx_timer;
48 struct timer_list tx_timer;
51 /* Microseconds that thread will delay waiting for a vcc port ref */
52 #define VCC_REF_DELAY 100
54 #define VCC_MAX_PORTS 1024
55 #define VCC_MINOR_START 0 /* must be zero */
56 #define VCC_BUFF_LEN VIO_VCC_MTU_SIZE
58 #define VCC_CTL_BREAK -1
59 #define VCC_CTL_HUP -2
61 static const char vcc_driver_name[] = "vcc";
62 static const char vcc_device_node[] = "vcc";
63 static struct tty_driver *vcc_tty_driver;
65 static struct vcc_port *vcc_table[VCC_MAX_PORTS];
66 static DEFINE_SPINLOCK(vcc_table_lock);
72 module_param(vcc_dbg, uint, 0664);
73 module_param(vcc_dbg_ldc, uint, 0664);
74 module_param(vcc_dbg_vio, uint, 0664);
76 #define VCC_DBG_DRV 0x1
77 #define VCC_DBG_LDC 0x2
78 #define VCC_DBG_PKT 0x4
80 #define vccdbg(f, a...) \
82 if (vcc_dbg & VCC_DBG_DRV) \
88 if (vcc_dbg & VCC_DBG_LDC) \
92 #define vccdbgp(pkt) \
94 if (vcc_dbg & VCC_DBG_PKT) { \
96 for (i = 0; i < pkt.tag.stype; i++) \
97 pr_info("[%c]", pkt.data[i]); \
101 /* Note: Be careful when adding flags to this line discipline. Don't
102 * add anything that will cause echoing or we'll go into recursive
103 * loop echoing chars back and forth with the console drivers.
105 static const struct ktermios vcc_tty_termios = {
106 .c_iflag = IGNBRK | IGNPAR,
108 .c_cflag = B38400 | CS8 | CREAD | HUPCL,
115 * vcc_table_add() - Add VCC port to the VCC table
116 * @port: pointer to the VCC port
118 * Return: index of the port in the VCC table on success,
121 static int vcc_table_add(struct vcc_port *port)
126 spin_lock_irqsave(&vcc_table_lock, flags);
127 for (i = VCC_MINOR_START; i < VCC_MAX_PORTS; i++) {
133 spin_unlock_irqrestore(&vcc_table_lock, flags);
135 if (i < VCC_MAX_PORTS)
142 * vcc_table_remove() - Removes a VCC port from the VCC table
143 * @index: Index into the VCC table
145 static void vcc_table_remove(unsigned long index)
149 if (WARN_ON(index >= VCC_MAX_PORTS))
152 spin_lock_irqsave(&vcc_table_lock, flags);
153 vcc_table[index] = NULL;
154 spin_unlock_irqrestore(&vcc_table_lock, flags);
158 * vcc_get() - Gets a reference to VCC port
159 * @index: Index into the VCC table
160 * @excl: Indicates if an exclusive access is requested
162 * Return: reference to the VCC port, if found
163 * NULL, if port not found
165 static struct vcc_port *vcc_get(unsigned long index, bool excl)
167 struct vcc_port *port;
171 spin_lock_irqsave(&vcc_table_lock, flags);
173 port = vcc_table[index];
175 spin_unlock_irqrestore(&vcc_table_lock, flags);
180 if (port->excl_locked) {
181 spin_unlock_irqrestore(&vcc_table_lock, flags);
182 udelay(VCC_REF_DELAY);
186 spin_unlock_irqrestore(&vcc_table_lock, flags);
191 spin_unlock_irqrestore(&vcc_table_lock, flags);
192 /* Threads wanting exclusive access will wait half the time,
193 * probably giving them higher priority in the case of
196 udelay(VCC_REF_DELAY/2);
201 port->excl_locked = true;
202 spin_unlock_irqrestore(&vcc_table_lock, flags);
208 * vcc_put() - Returns a reference to VCC port
209 * @port: pointer to VCC port
210 * @excl: Indicates if the returned reference is an exclusive reference
212 * Note: It's the caller's responsibility to ensure the correct value
215 static void vcc_put(struct vcc_port *port, bool excl)
222 spin_lock_irqsave(&vcc_table_lock, flags);
224 /* check if caller attempted to put with the wrong flags */
225 if (WARN_ON((excl && !port->excl_locked) ||
226 (!excl && port->excl_locked)))
232 port->excl_locked = false;
235 spin_unlock_irqrestore(&vcc_table_lock, flags);
239 * vcc_get_ne() - Get a non-exclusive reference to VCC port
240 * @index: Index into the VCC table
242 * Gets a non-exclusive reference to VCC port, if it's not removed
244 * Return: pointer to the VCC port, if found
245 * NULL, if port not found
247 static struct vcc_port *vcc_get_ne(unsigned long index)
249 struct vcc_port *port;
251 port = vcc_get(index, false);
253 if (port && port->removed) {
254 vcc_put(port, false);
261 static void vcc_kick_rx(struct vcc_port *port)
263 struct vio_driver_state *vio = &port->vio;
265 assert_spin_locked(&port->lock);
267 if (!timer_pending(&port->rx_timer) && !port->removed) {
268 disable_irq_nosync(vio->vdev->rx_irq);
269 port->rx_timer.expires = (jiffies + 1);
270 add_timer(&port->rx_timer);
274 static void vcc_kick_tx(struct vcc_port *port)
276 assert_spin_locked(&port->lock);
278 if (!timer_pending(&port->tx_timer) && !port->removed) {
279 port->tx_timer.expires = (jiffies + 1);
280 add_timer(&port->tx_timer);
284 static int vcc_rx_check(struct tty_struct *tty, int size)
286 if (WARN_ON(!tty || !tty->port))
289 /* tty_buffer_request_room won't sleep because it uses
290 * GFP_ATOMIC flag to allocate buffer
292 if (test_bit(TTY_THROTTLED, &tty->flags) ||
293 (tty_buffer_request_room(tty->port, VCC_BUFF_LEN) < VCC_BUFF_LEN))
299 static int vcc_rx(struct tty_struct *tty, char *buf, int size)
303 if (WARN_ON(!tty || !tty->port))
306 len = tty_insert_flip_string(tty->port, buf, size);
308 tty_flip_buffer_push(tty->port);
313 static int vcc_ldc_read(struct vcc_port *port)
315 struct vio_driver_state *vio = &port->vio;
316 struct tty_struct *tty;
322 rv = ldc_rx_reset(vio->lp);
323 vccdbg("VCC: reset rx q: rv=%d\n", rv);
327 /* Read as long as LDC has incoming data. */
329 if (!vcc_rx_check(tty, VIO_VCC_MTU_SIZE)) {
336 rv = ldc_read(vio->lp, &pkt, sizeof(pkt));
340 vccdbg("VCC: ldc_read()=%d\n", rv);
341 vccdbg("TAG [%02x:%02x:%04x:%08x]\n",
342 pkt.tag.type, pkt.tag.stype,
343 pkt.tag.stype_env, pkt.tag.sid);
345 if (pkt.tag.type == VIO_TYPE_DATA) {
347 /* vcc_rx_check ensures memory availability */
348 vcc_rx(tty, pkt.data, pkt.tag.stype);
350 pr_err("VCC: unknown msg [%02x:%02x:%04x:%08x]\n",
351 pkt.tag.type, pkt.tag.stype,
352 pkt.tag.stype_env, pkt.tag.sid);
357 WARN_ON(rv != LDC_PACKET_SIZE);
364 static void vcc_rx_timer(struct timer_list *t)
366 struct vcc_port *port = from_timer(port, t, rx_timer);
367 struct vio_driver_state *vio;
371 spin_lock_irqsave(&port->lock, flags);
372 port->rx_timer.expires = 0;
376 enable_irq(vio->vdev->rx_irq);
378 if (!port->tty || port->removed)
381 rv = vcc_ldc_read(port);
382 if (rv == -ECONNRESET)
386 spin_unlock_irqrestore(&port->lock, flags);
387 vcc_put(port, false);
390 static void vcc_tx_timer(struct timer_list *t)
392 struct vcc_port *port = from_timer(port, t, tx_timer);
398 spin_lock_irqsave(&port->lock, flags);
399 port->tx_timer.expires = 0;
401 if (!port->tty || port->removed)
404 tosend = min(VCC_BUFF_LEN, port->chars_in_buffer);
409 pkt->tag.type = VIO_TYPE_DATA;
410 pkt->tag.stype = tosend;
411 vccdbgl(port->vio.lp);
413 rv = ldc_write(port->vio.lp, pkt, (VIO_TAG_SIZE + tosend));
417 vccdbg("VCC: ldc_write()=%d\n", rv);
420 struct tty_struct *tty = port->tty;
422 port->chars_in_buffer = 0;
428 spin_unlock_irqrestore(&port->lock, flags);
429 vcc_put(port, false);
433 * vcc_event() - LDC event processing engine
434 * @arg: VCC private data
437 * Handles LDC events for VCC
439 static void vcc_event(void *arg, int event)
441 struct vio_driver_state *vio;
442 struct vcc_port *port;
449 spin_lock_irqsave(&port->lock, flags);
452 case LDC_EVENT_RESET:
454 vio_link_state_change(vio, event);
457 case LDC_EVENT_DATA_READY:
458 rv = vcc_ldc_read(port);
459 if (rv == -ECONNRESET)
464 pr_err("VCC: unexpected LDC event(%d)\n", event);
467 spin_unlock_irqrestore(&port->lock, flags);
470 static struct ldc_channel_config vcc_ldc_cfg = {
472 .mtu = VIO_VCC_MTU_SIZE,
473 .mode = LDC_MODE_RAW,
477 /* Ordered from largest major to lowest */
478 static struct vio_version vcc_versions[] = {
479 { .major = 1, .minor = 0 },
482 static struct tty_port_operations vcc_port_ops = { 0 };
484 static ssize_t vcc_sysfs_domain_show(struct device *dev,
485 struct device_attribute *attr,
488 struct vcc_port *port;
491 port = dev_get_drvdata(dev);
495 rv = scnprintf(buf, PAGE_SIZE, "%s\n", port->domain);
500 static int vcc_send_ctl(struct vcc_port *port, int ctl)
505 pkt.tag.type = VIO_TYPE_CTRL;
509 rv = ldc_write(port->vio.lp, &pkt, sizeof(pkt.tag));
511 vccdbg("VCC: ldc_write(%ld)=%d\n", sizeof(pkt.tag), rv);
516 static ssize_t vcc_sysfs_break_store(struct device *dev,
517 struct device_attribute *attr,
518 const char *buf, size_t count)
520 struct vcc_port *port;
525 port = dev_get_drvdata(dev);
529 spin_lock_irqsave(&port->lock, flags);
531 if (sscanf(buf, "%ud", &brk) != 1 || brk != 1)
533 else if (vcc_send_ctl(port, VCC_CTL_BREAK) < 0)
536 spin_unlock_irqrestore(&port->lock, flags);
541 static DEVICE_ATTR(domain, 0400, vcc_sysfs_domain_show, NULL);
542 static DEVICE_ATTR(break, 0200, NULL, vcc_sysfs_break_store);
544 static struct attribute *vcc_sysfs_entries[] = {
545 &dev_attr_domain.attr,
546 &dev_attr_break.attr,
550 static struct attribute_group vcc_attribute_group = {
552 .attrs = vcc_sysfs_entries,
556 * vcc_probe() - Initialize VCC port
557 * @vdev: Pointer to VIO device of the new VCC port
560 * Initializes a VCC port to receive serial console data from
561 * the guest domain. Sets up a TTY end point on the control
562 * domain. Sets up VIO/LDC link between the guest & control
565 * Return: status of the probe
567 static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
569 struct mdesc_handle *hp;
570 struct vcc_port *port;
577 vccdbg("VCC: name=%s\n", dev_name(&vdev->dev));
579 if (!vcc_tty_driver) {
580 pr_err("VCC: TTY driver not registered\n");
584 port = kzalloc(sizeof(struct vcc_port), GFP_KERNEL);
588 name = kstrdup(dev_name(&vdev->dev), GFP_KERNEL);
590 rv = vio_driver_init(&port->vio, vdev, VDEV_CONSOLE_CON, vcc_versions,
591 ARRAY_SIZE(vcc_versions), NULL, name);
595 port->vio.debug = vcc_dbg_vio;
596 vcc_ldc_cfg.debug = vcc_dbg_ldc;
598 rv = vio_ldc_alloc(&port->vio, &vcc_ldc_cfg, port);
602 spin_lock_init(&port->lock);
604 port->index = vcc_table_add(port);
605 if (port->index == -1) {
606 pr_err("VCC: no more TTY indices left for allocation\n");
610 /* Register the device using VCC table index as TTY index */
611 dev = tty_register_device(vcc_tty_driver, port->index, &vdev->dev);
619 node = vio_vdev_node(hp, vdev);
620 if (node == MDESC_NODE_NULL) {
626 domain = mdesc_get_property(hp, node, "vcc-domain-name", NULL);
632 port->domain = kstrdup(domain, GFP_KERNEL);
636 rv = sysfs_create_group(&vdev->dev.kobj, &vcc_attribute_group);
640 timer_setup(&port->rx_timer, vcc_rx_timer, 0);
641 timer_setup(&port->tx_timer, vcc_tx_timer, 0);
643 dev_set_drvdata(&vdev->dev, port);
645 /* It's possible to receive IRQs in the middle of vio_port_up. Disable
646 * IRQs until the port is up.
648 disable_irq_nosync(vdev->rx_irq);
649 vio_port_up(&port->vio);
650 enable_irq(vdev->rx_irq);
657 tty_unregister_device(vcc_tty_driver, port->index);
659 vcc_table_remove(port->index);
661 vio_ldc_free(&port->vio);
670 * vcc_remove() - Terminate a VCC port
671 * @vdev: Pointer to VIO device of the VCC port
673 * Terminates a VCC port. Sets up the teardown of TTY and
674 * VIO/LDC link between guest and primary domains.
676 * Return: status of removal
678 static int vcc_remove(struct vio_dev *vdev)
680 struct vcc_port *port = dev_get_drvdata(&vdev->dev);
685 del_timer_sync(&port->rx_timer);
686 del_timer_sync(&port->tx_timer);
688 /* If there's a process with the device open, do a synchronous
689 * hangup of the TTY. This *may* cause the process to call close
690 * asynchronously, but it's not guaranteed.
693 tty_vhangup(port->tty);
695 /* Get exclusive reference to VCC, ensures that there are no other
696 * clients to this port
698 port = vcc_get(port->index, true);
703 tty_unregister_device(vcc_tty_driver, port->index);
705 del_timer_sync(&port->vio.timer);
706 vio_ldc_free(&port->vio);
707 sysfs_remove_group(&vdev->dev.kobj, &vcc_attribute_group);
708 dev_set_drvdata(&vdev->dev, NULL);
710 port->removed = true;
713 vcc_table_remove(port->index);
715 kfree(port->vio.name);
723 static const struct vio_device_id vcc_match[] = {
729 MODULE_DEVICE_TABLE(vio, vcc_match);
731 static struct vio_driver vcc_driver = {
732 .id_table = vcc_match,
734 .remove = vcc_remove,
738 static int vcc_open(struct tty_struct *tty, struct file *vcc_file)
740 struct vcc_port *port;
742 if (unlikely(!tty)) {
743 pr_err("VCC: open: Invalid TTY handle\n");
750 port = vcc_get_ne(tty->index);
751 if (unlikely(!port)) {
752 pr_err("VCC: open: Failed to find VCC port\n");
756 if (unlikely(!port->vio.lp)) {
757 pr_err("VCC: open: LDC channel not configured\n");
758 vcc_put(port, false);
761 vccdbgl(port->vio.lp);
763 vcc_put(port, false);
765 if (unlikely(!tty->port)) {
766 pr_err("VCC: open: TTY port not found\n");
770 if (unlikely(!tty->port->ops)) {
771 pr_err("VCC: open: TTY ops not defined\n");
775 return tty_port_open(tty->port, tty, vcc_file);
778 static void vcc_close(struct tty_struct *tty, struct file *vcc_file)
780 if (unlikely(!tty)) {
781 pr_err("VCC: close: Invalid TTY handle\n");
785 if (unlikely(tty->count > 1))
788 if (unlikely(!tty->port)) {
789 pr_err("VCC: close: TTY port not found\n");
793 tty_port_close(tty->port, tty, vcc_file);
796 static void vcc_ldc_hup(struct vcc_port *port)
800 spin_lock_irqsave(&port->lock, flags);
802 if (vcc_send_ctl(port, VCC_CTL_HUP) < 0)
805 spin_unlock_irqrestore(&port->lock, flags);
808 static void vcc_hangup(struct tty_struct *tty)
810 struct vcc_port *port;
812 if (unlikely(!tty)) {
813 pr_err("VCC: hangup: Invalid TTY handle\n");
817 port = vcc_get_ne(tty->index);
818 if (unlikely(!port)) {
819 pr_err("VCC: hangup: Failed to find VCC port\n");
823 if (unlikely(!tty->port)) {
824 pr_err("VCC: hangup: TTY port not found\n");
825 vcc_put(port, false);
831 vcc_put(port, false);
833 tty_port_hangup(tty->port);
836 static int vcc_write(struct tty_struct *tty, const unsigned char *buf,
839 struct vcc_port *port;
846 if (unlikely(!tty)) {
847 pr_err("VCC: write: Invalid TTY handle\n");
851 port = vcc_get_ne(tty->index);
852 if (unlikely(!port)) {
853 pr_err("VCC: write: Failed to find VCC port");
857 spin_lock_irqsave(&port->lock, flags);
860 pkt->tag.type = VIO_TYPE_DATA;
863 /* Minimum of data to write and space available */
864 tosend = min(count, (VCC_BUFF_LEN - port->chars_in_buffer));
869 memcpy(&pkt->data[port->chars_in_buffer], &buf[total_sent],
871 port->chars_in_buffer += tosend;
872 pkt->tag.stype = tosend;
874 vccdbg("TAG [%02x:%02x:%04x:%08x]\n", pkt->tag.type,
875 pkt->tag.stype, pkt->tag.stype_env, pkt->tag.sid);
876 vccdbg("DATA [%s]\n", pkt->data);
877 vccdbgl(port->vio.lp);
879 /* Since we know we have enough room in VCC buffer for tosend
880 * we record that it was sent regardless of whether the
881 * hypervisor actually took it because we have it buffered.
883 rv = ldc_write(port->vio.lp, pkt, (VIO_TAG_SIZE + tosend));
884 vccdbg("VCC: write: ldc_write(%d)=%d\n",
885 (VIO_TAG_SIZE + tosend), rv);
887 total_sent += tosend;
894 port->chars_in_buffer = 0;
897 spin_unlock_irqrestore(&port->lock, flags);
899 vcc_put(port, false);
901 vccdbg("VCC: write: total=%d rv=%d", total_sent, rv);
903 return total_sent ? total_sent : rv;
906 static int vcc_write_room(struct tty_struct *tty)
908 struct vcc_port *port;
911 if (unlikely(!tty)) {
912 pr_err("VCC: write_room: Invalid TTY handle\n");
916 port = vcc_get_ne(tty->index);
917 if (unlikely(!port)) {
918 pr_err("VCC: write_room: Failed to find VCC port\n");
922 num = VCC_BUFF_LEN - port->chars_in_buffer;
924 vcc_put(port, false);
929 static int vcc_chars_in_buffer(struct tty_struct *tty)
931 struct vcc_port *port;
934 if (unlikely(!tty)) {
935 pr_err("VCC: chars_in_buffer: Invalid TTY handle\n");
939 port = vcc_get_ne(tty->index);
940 if (unlikely(!port)) {
941 pr_err("VCC: chars_in_buffer: Failed to find VCC port\n");
945 num = port->chars_in_buffer;
947 vcc_put(port, false);
952 static int vcc_break_ctl(struct tty_struct *tty, int state)
954 struct vcc_port *port;
957 if (unlikely(!tty)) {
958 pr_err("VCC: break_ctl: Invalid TTY handle\n");
962 port = vcc_get_ne(tty->index);
963 if (unlikely(!port)) {
964 pr_err("VCC: break_ctl: Failed to find VCC port\n");
970 vcc_put(port, false);
974 spin_lock_irqsave(&port->lock, flags);
976 if (vcc_send_ctl(port, VCC_CTL_BREAK) < 0)
979 spin_unlock_irqrestore(&port->lock, flags);
981 vcc_put(port, false);
986 static int vcc_install(struct tty_driver *driver, struct tty_struct *tty)
988 struct vcc_port *port_vcc;
989 struct tty_port *port_tty;
992 if (unlikely(!tty)) {
993 pr_err("VCC: install: Invalid TTY handle\n");
997 if (tty->index >= VCC_MAX_PORTS)
1000 ret = tty_standard_install(driver, tty);
1004 port_tty = kzalloc(sizeof(struct tty_port), GFP_KERNEL);
1008 port_vcc = vcc_get(tty->index, true);
1010 pr_err("VCC: install: Failed to find VCC port\n");
1016 tty_port_init(port_tty);
1017 port_tty->ops = &vcc_port_ops;
1018 tty->port = port_tty;
1020 port_vcc->tty = tty;
1022 vcc_put(port_vcc, true);
1027 static void vcc_cleanup(struct tty_struct *tty)
1029 struct vcc_port *port;
1031 if (unlikely(!tty)) {
1032 pr_err("VCC: cleanup: Invalid TTY handle\n");
1036 port = vcc_get(tty->index, true);
1040 if (port->removed) {
1041 vcc_table_remove(tty->index);
1042 kfree(port->vio.name);
1043 kfree(port->domain);
1046 vcc_put(port, true);
1050 tty_port_destroy(tty->port);
1055 static const struct tty_operations vcc_ops = {
1058 .hangup = vcc_hangup,
1060 .write_room = vcc_write_room,
1061 .chars_in_buffer = vcc_chars_in_buffer,
1062 .break_ctl = vcc_break_ctl,
1063 .install = vcc_install,
1064 .cleanup = vcc_cleanup,
1067 #define VCC_TTY_FLAGS (TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_REAL_RAW)
1069 static int vcc_tty_init(void)
1073 pr_info("VCC: %s\n", version);
1075 vcc_tty_driver = tty_alloc_driver(VCC_MAX_PORTS, VCC_TTY_FLAGS);
1076 if (IS_ERR(vcc_tty_driver)) {
1077 pr_err("VCC: TTY driver alloc failed\n");
1078 return PTR_ERR(vcc_tty_driver);
1081 vcc_tty_driver->driver_name = vcc_driver_name;
1082 vcc_tty_driver->name = vcc_device_node;
1084 vcc_tty_driver->minor_start = VCC_MINOR_START;
1085 vcc_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM;
1086 vcc_tty_driver->init_termios = vcc_tty_termios;
1088 tty_set_operations(vcc_tty_driver, &vcc_ops);
1090 rv = tty_register_driver(vcc_tty_driver);
1092 pr_err("VCC: TTY driver registration failed\n");
1093 put_tty_driver(vcc_tty_driver);
1094 vcc_tty_driver = NULL;
1098 vccdbg("VCC: TTY driver registered\n");
1103 static void vcc_tty_exit(void)
1105 tty_unregister_driver(vcc_tty_driver);
1106 put_tty_driver(vcc_tty_driver);
1107 vccdbg("VCC: TTY driver unregistered\n");
1109 vcc_tty_driver = NULL;
1112 static int __init vcc_init(void)
1116 rv = vcc_tty_init();
1118 pr_err("VCC: TTY init failed\n");
1122 rv = vio_register_driver(&vcc_driver);
1124 pr_err("VCC: VIO driver registration failed\n");
1127 vccdbg("VCC: VIO driver registered successfully\n");
1133 static void __exit vcc_exit(void)
1135 vio_unregister_driver(&vcc_driver);
1136 vccdbg("VCC: VIO driver unregistered\n");
1138 vccdbg("VCC: TTY driver unregistered\n");
1141 module_init(vcc_init);
1142 module_exit(vcc_exit);