diff options
Diffstat (limited to 'drivers/usb/gadget/u_serial.c')
| -rw-r--r-- | drivers/usb/gadget/u_serial.c | 707 |
1 files changed, 404 insertions, 303 deletions
diff --git a/drivers/usb/gadget/u_serial.c b/drivers/usb/gadget/u_serial.c index abf9505d3a7..ad0aca81200 100644 --- a/drivers/usb/gadget/u_serial.c +++ b/drivers/usb/gadget/u_serial.c @@ -18,11 +18,15 @@ /* #define VERBOSE_DEBUG */ #include <linux/kernel.h> +#include <linux/sched.h> #include <linux/interrupt.h> #include <linux/device.h> #include <linux/delay.h> #include <linux/tty.h> #include <linux/tty_flip.h> +#include <linux/slab.h> +#include <linux/export.h> +#include <linux/module.h> #include "u_serial.h" @@ -32,11 +36,12 @@ * "serial port" functionality through the USB gadget stack. Each such * port is exposed through a /dev/ttyGS* node. * - * After initialization (gserial_setup), these TTY port devices stay - * available until they are removed (gserial_cleanup). Each one may be - * connected to a USB function (gserial_connect), or disconnected (with - * gserial_disconnect) when the USB host issues a config change event. - * Data can only flow when the port is connected to the host. + * After this module has been loaded, the individual TTY port can be requested + * (gserial_alloc_line()) and it will stay available until they are removed + * (gserial_free_line()). Each one may be connected to a USB function + * (gserial_connect), or disconnected (with gserial_disconnect) when the USB + * host issues a config change event. Data can only flow when the port is + * connected to the host. * * A given TTY port can be made available in multiple configurations. * For example, each one might expose a ttyGS0 node which provides a @@ -52,13 +57,16 @@ * is managed in userspace ... OBEX, PTP, and MTP have been mentioned. */ +#define PREFIX "ttyGS" + /* * gserial is the lifecycle interface, used by USB functions * gs_port is the I/O nexus, used by the tty driver * tty_struct links to the tty/filesystem framework * * gserial <---> gs_port ... links will be null when the USB link is - * inactive; managed by gserial_{connect,disconnect}(). + * inactive; managed by gserial_{connect,disconnect}(). each gserial + * instance can wrap its own USB control protocol. * gserial->ioport == usb_ep->driver_data ... gs_port * gs_port->port_usb ... gserial * @@ -88,21 +96,24 @@ struct gs_buf { * (and thus for each /dev/ node). */ struct gs_port { + struct tty_port port; spinlock_t port_lock; /* guard port_* access */ struct gserial *port_usb; - struct tty_struct *port_tty; - unsigned open_count; bool openclose; /* open/close in progress */ u8 port_num; - wait_queue_head_t close_wait; /* wait for last close */ - struct list_head read_pool; + int read_started; + int read_allocated; + struct list_head read_queue; + unsigned n_read; struct tasklet_struct push; struct list_head write_pool; + int write_started; + int write_allocated; struct gs_buf port_write_buf; wait_queue_head_t drain_wait; /* wait while writes drain */ @@ -110,24 +121,25 @@ struct gs_port { struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */ }; -/* increase N_PORTS if you need more */ -#define N_PORTS 4 static struct portmaster { struct mutex lock; /* protect open/close */ struct gs_port *port; -} ports[N_PORTS]; -static unsigned n_ports; +} ports[MAX_U_SERIAL_PORTS]; #define GS_CLOSE_TIMEOUT 15 /* seconds */ #ifdef VERBOSE_DEBUG +#ifndef pr_vdebug #define pr_vdebug(fmt, arg...) \ pr_debug(fmt, ##arg) +#endif /* pr_vdebug */ #else +#ifndef pr_vdebug #define pr_vdebug(fmt, arg...) \ ({ if (0) pr_debug(fmt, ##arg); }) +#endif /* pr_vdebug */ #endif /*-------------------------------------------------------------------------*/ @@ -177,7 +189,7 @@ static void gs_buf_clear(struct gs_buf *gb) /* * gs_buf_data_avail * - * Return the number of bytes of data available in the circular + * Return the number of bytes of data written into the circular * buffer. */ static unsigned gs_buf_data_avail(struct gs_buf *gb) @@ -278,7 +290,7 @@ gs_buf_get(struct gs_buf *gb, char *buf, unsigned count) * Allocate a usb_request and its buffer. Returns a pointer to the * usb_request or NULL if there is an error. */ -static struct usb_request * +struct usb_request * gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t kmalloc_flags) { struct usb_request *req; @@ -296,17 +308,19 @@ gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t kmalloc_flags) return req; } +EXPORT_SYMBOL_GPL(gs_alloc_req); /* * gs_free_req * * Free a usb_request and its buffer. */ -static void gs_free_req(struct usb_ep *ep, struct usb_request *req) +void gs_free_req(struct usb_ep *ep, struct usb_request *req) { kfree(req->buf); usb_ep_free_request(ep, req); } +EXPORT_SYMBOL_GPL(gs_free_req); /* * gs_send_packet @@ -356,6 +370,9 @@ __acquires(&port->port_lock) struct usb_request *req; int len; + if (port->write_started >= QUEUE_SIZE) + break; + req = list_entry(pool->next, struct usb_request, list); len = gs_send_packet(port, req->buf, in->maxpacket); if (len == 0) { @@ -366,12 +383,11 @@ __acquires(&port->port_lock) req->length = len; list_del(&req->list); + req->zero = (gs_buf_data_avail(&port->port_write_buf) == 0); -#ifdef VERBOSE_DEBUG - pr_debug("%s: %s, len=%d, 0x%02x 0x%02x 0x%02x ...\n", - __func__, in->name, len, *((u8 *)req->buf), + pr_vdebug(PREFIX "%d: tx len=%d, 0x%02x 0x%02x 0x%02x ...\n", + port->port_num, len, *((u8 *)req->buf), *((u8 *)req->buf+1), *((u8 *)req->buf+2)); -#endif /* Drop lock while we call out of driver; completions * could be issued while we do so. Disconnection may @@ -391,66 +407,18 @@ __acquires(&port->port_lock) break; } + port->write_started++; + /* abort immediately after disconnect */ if (!port->port_usb) break; } - if (do_tty_wake && port->port_tty) - tty_wakeup(port->port_tty); + if (do_tty_wake && port->port.tty) + tty_wakeup(port->port.tty); return status; } -static void gs_rx_push(unsigned long _port) -{ - struct gs_port *port = (void *)_port; - struct tty_struct *tty = port->port_tty; - - /* With low_latency, tty_flip_buffer_push() doesn't put its - * real work through a workqueue, so the ldisc has a better - * chance to keep up with peak USB data rates. - */ - if (tty) { - tty_flip_buffer_push(tty); - wake_up_interruptible(&tty->read_wait); - } -} - -/* - * gs_recv_packet - * - * Called for each USB packet received. Reads the packet - * header and stuffs the data in the appropriate tty buffer. - * Returns 0 if successful, or a negative error number. - * - * Called during USB completion routine, on interrupt time. - * With port_lock. - */ -static int gs_recv_packet(struct gs_port *port, char *packet, unsigned size) -{ - unsigned len; - struct tty_struct *tty; - - /* I/O completions can continue for a while after close(), until the - * request queue empties. Just discard any data we receive, until - * something reopens this TTY ... as if there were no HW flow control. - */ - tty = port->port_tty; - if (tty == NULL) { - pr_vdebug("%s: ttyGS%d, after close\n", - __func__, port->port_num); - return -EIO; - } - - len = tty_insert_flip_string(tty, packet, size); - if (len > 0) - tasklet_schedule(&port->push); - if (len < size) - pr_debug("%s: ttyGS%d, drop %d bytes\n", - __func__, port->port_num, size - len); - return 0; -} - /* * Context: caller owns port_lock, and port_usb is set */ @@ -462,16 +430,18 @@ __acquires(&port->port_lock) { struct list_head *pool = &port->read_pool; struct usb_ep *out = port->port_usb->out; - unsigned started = 0; while (!list_empty(pool)) { struct usb_request *req; int status; struct tty_struct *tty; - /* no more rx if closed or throttled */ - tty = port->port_tty; - if (!tty || test_bit(TTY_THROTTLED, &tty->flags)) + /* no more rx if closed */ + tty = port->port.tty; + if (!tty) + break; + + if (port->read_started >= QUEUE_SIZE) break; req = list_entry(pool->next, struct usb_request, list); @@ -491,45 +461,134 @@ __acquires(&port->port_lock) list_add(&req->list, pool); break; } - started++; + port->read_started++; /* abort immediately after disconnect */ if (!port->port_usb) break; } - return started; + return port->read_started; } -static void gs_read_complete(struct usb_ep *ep, struct usb_request *req) +/* + * RX tasklet takes data out of the RX queue and hands it up to the TTY + * layer until it refuses to take any more data (or is throttled back). + * Then it issues reads for any further data. + * + * If the RX queue becomes full enough that no usb_request is queued, + * the OUT endpoint may begin NAKing as soon as its FIFO fills up. + * So QUEUE_SIZE packets plus however many the FIFO holds (usually two) + * can be buffered before the TTY layer's buffers (currently 64 KB). + */ +static void gs_rx_push(unsigned long _port) { - int status; - struct gs_port *port = ep->driver_data; + struct gs_port *port = (void *)_port; + struct tty_struct *tty; + struct list_head *queue = &port->read_queue; + bool disconnect = false; + bool do_push = false; - spin_lock(&port->port_lock); - list_add(&req->list, &port->read_pool); + /* hand any queued data to the tty */ + spin_lock_irq(&port->port_lock); + tty = port->port.tty; + while (!list_empty(queue)) { + struct usb_request *req; - switch (req->status) { - case 0: - /* normal completion */ - status = gs_recv_packet(port, req->buf, req->actual); - if (status && status != -EIO) - pr_debug("%s: %s %s err %d\n", - __func__, "recv", ep->name, status); - gs_start_rx(port); - break; + req = list_first_entry(queue, struct usb_request, list); - case -ESHUTDOWN: - /* disconnect */ - pr_vdebug("%s: %s shutdown\n", __func__, ep->name); - break; + /* leave data queued if tty was rx throttled */ + if (tty && test_bit(TTY_THROTTLED, &tty->flags)) + break; - default: - /* presumably a transient fault */ - pr_warning("%s: unexpected %s status %d\n", - __func__, ep->name, req->status); - gs_start_rx(port); - break; + switch (req->status) { + case -ESHUTDOWN: + disconnect = true; + pr_vdebug(PREFIX "%d: shutdown\n", port->port_num); + break; + + default: + /* presumably a transient fault */ + pr_warning(PREFIX "%d: unexpected RX status %d\n", + port->port_num, req->status); + /* FALLTHROUGH */ + case 0: + /* normal completion */ + break; + } + + /* push data to (open) tty */ + if (req->actual) { + char *packet = req->buf; + unsigned size = req->actual; + unsigned n; + int count; + + /* we may have pushed part of this packet already... */ + n = port->n_read; + if (n) { + packet += n; + size -= n; + } + + count = tty_insert_flip_string(&port->port, packet, + size); + if (count) + do_push = true; + if (count != size) { + /* stop pushing; TTY layer can't handle more */ + port->n_read += count; + pr_vdebug(PREFIX "%d: rx block %d/%d\n", + port->port_num, + count, req->actual); + break; + } + port->n_read = 0; + } + + list_move(&req->list, &port->read_pool); + port->read_started--; } + + /* Push from tty to ldisc; this is handled by a workqueue, + * so we won't get callbacks and can hold port_lock + */ + if (do_push) + tty_flip_buffer_push(&port->port); + + + /* We want our data queue to become empty ASAP, keeping data + * in the tty and ldisc (not here). If we couldn't push any + * this time around, there may be trouble unless there's an + * implicit tty_unthrottle() call on its way... + * + * REVISIT we should probably add a timer to keep the tasklet + * from starving ... but it's not clear that case ever happens. + */ + if (!list_empty(queue) && tty) { + if (!test_bit(TTY_THROTTLED, &tty->flags)) { + if (do_push) + tasklet_schedule(&port->push); + else + pr_warning(PREFIX "%d: RX not scheduled?\n", + port->port_num); + } + } + + /* If we're still connected, refill the USB RX queue. */ + if (!disconnect && port->port_usb) + gs_start_rx(port); + + spin_unlock_irq(&port->port_lock); +} + +static void gs_read_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct gs_port *port = ep->driver_data; + + /* Queue all received data until the tty layer is ready for it. */ + spin_lock(&port->port_lock); + list_add_tail(&req->list, &port->read_queue); + tasklet_schedule(&port->push); spin_unlock(&port->port_lock); } @@ -539,6 +598,7 @@ static void gs_write_complete(struct usb_ep *ep, struct usb_request *req) spin_lock(&port->port_lock); list_add(&req->list, &port->write_pool); + port->write_started--; switch (req->status) { default: @@ -560,7 +620,8 @@ static void gs_write_complete(struct usb_ep *ep, struct usb_request *req) spin_unlock(&port->port_lock); } -static void gs_free_requests(struct usb_ep *ep, struct list_head *head) +static void gs_free_requests(struct usb_ep *ep, struct list_head *head, + int *allocated) { struct usb_request *req; @@ -568,25 +629,31 @@ static void gs_free_requests(struct usb_ep *ep, struct list_head *head) req = list_entry(head->next, struct usb_request, list); list_del(&req->list); gs_free_req(ep, req); + if (allocated) + (*allocated)--; } } static int gs_alloc_requests(struct usb_ep *ep, struct list_head *head, - void (*fn)(struct usb_ep *, struct usb_request *)) + void (*fn)(struct usb_ep *, struct usb_request *), + int *allocated) { int i; struct usb_request *req; + int n = allocated ? QUEUE_SIZE - *allocated : QUEUE_SIZE; /* Pre-allocate up to QUEUE_SIZE transfers, but if we can't * do quite that many this time, don't fail ... we just won't * be as speedy as we might otherwise be. */ - for (i = 0; i < QUEUE_SIZE; i++) { + for (i = 0; i < n; i++) { req = gs_alloc_req(ep, ep->maxpacket, GFP_ATOMIC); if (!req) return list_empty(head) ? -ENOMEM : 0; req->complete = fn; list_add_tail(&req->list, head); + if (allocated) + (*allocated)++; } return 0; } @@ -613,29 +680,33 @@ static int gs_start_io(struct gs_port *port) * configurations may use different endpoints with a given port; * and high speed vs full speed changes packet sizes too. */ - status = gs_alloc_requests(ep, head, gs_read_complete); + status = gs_alloc_requests(ep, head, gs_read_complete, + &port->read_allocated); if (status) return status; status = gs_alloc_requests(port->port_usb->in, &port->write_pool, - gs_write_complete); + gs_write_complete, &port->write_allocated); if (status) { - gs_free_requests(ep, head); + gs_free_requests(ep, head, &port->read_allocated); return status; } /* queue read requests */ + port->n_read = 0; started = gs_start_rx(port); /* unblock any pending writes into our circular buffer */ if (started) { - tty_wakeup(port->port_tty); + tty_wakeup(port->port.tty); } else { - gs_free_requests(ep, head); - gs_free_requests(port->port_usb->in, &port->write_pool); + gs_free_requests(ep, head, &port->read_allocated); + gs_free_requests(port->port_usb->in, &port->write_pool, + &port->write_allocated); + status = -EIO; } - return started ? 0 : status; + return status; } /*-------------------------------------------------------------------------*/ @@ -653,9 +724,6 @@ static int gs_open(struct tty_struct *tty, struct file *file) struct gs_port *port; int status; - if (port_num < 0 || port_num >= n_ports) - return -ENXIO; - do { mutex_lock(&ports[port_num].lock); port = ports[port_num].port; @@ -665,9 +733,9 @@ static int gs_open(struct tty_struct *tty, struct file *file) spin_lock_irq(&port->port_lock); /* already open? Great. */ - if (port->open_count) { + if (port->port.count) { status = 0; - port->open_count++; + port->port.count++; /* currently opening/closing? wait ... */ } else if (port->openclose) { @@ -724,22 +792,20 @@ static int gs_open(struct tty_struct *tty, struct file *file) /* REVISIT maybe wait for "carrier detect" */ tty->driver_data = port; - port->port_tty = tty; + port->port.tty = tty; - port->open_count = 1; + port->port.count = 1; port->openclose = false; - /* low_latency means ldiscs work in tasklet context, without - * needing a workqueue schedule ... easier to keep up. - */ - tty->low_latency = 1; - /* if connected, start the I/O stream */ if (port->port_usb) { + struct gserial *gser = port->port_usb; + pr_debug("gs_open: start ttyGS%d\n", port->port_num); gs_start_io(port); - /* REVISIT for ACM, issue "network connected" event */ + if (gser->connect) + gser->connect(gser); } pr_debug("gs_open: ttyGS%d (%p,%p)\n", port->port_num, tty, file); @@ -766,14 +832,15 @@ static int gs_writes_finished(struct gs_port *p) static void gs_close(struct tty_struct *tty, struct file *file) { struct gs_port *port = tty->driver_data; + struct gserial *gser; spin_lock_irq(&port->port_lock); - if (port->open_count != 1) { - if (port->open_count == 0) + if (port->port.count != 1) { + if (port->port.count == 0) WARN_ON(1); else - --port->open_count; + --port->port.count; goto exit; } @@ -783,43 +850,42 @@ static void gs_close(struct tty_struct *tty, struct file *file) * and sleep if necessary */ port->openclose = true; - port->open_count = 0; + port->port.count = 0; - if (port->port_usb) - /* REVISIT for ACM, issue "network disconnected" event */; + gser = port->port_usb; + if (gser && gser->disconnect) + gser->disconnect(gser); /* wait for circular write buffer to drain, disconnect, or at * most GS_CLOSE_TIMEOUT seconds; then discard the rest */ - if (gs_buf_data_avail(&port->port_write_buf) > 0 - && port->port_usb) { + if (gs_buf_data_avail(&port->port_write_buf) > 0 && gser) { spin_unlock_irq(&port->port_lock); wait_event_interruptible_timeout(port->drain_wait, gs_writes_finished(port), GS_CLOSE_TIMEOUT * HZ); spin_lock_irq(&port->port_lock); + gser = port->port_usb; } /* Iff we're disconnected, there can be no I/O in flight so it's * ok to free the circular buffer; else just scrub it. And don't * let the push tasklet fire again until we're re-opened. */ - if (port->port_usb == NULL) + if (gser == NULL) gs_buf_free(&port->port_write_buf); else gs_buf_clear(&port->port_write_buf); - tasklet_kill(&port->push); - tty->driver_data = NULL; - port->port_tty = NULL; + port->port.tty = NULL; port->openclose = false; pr_debug("gs_close: ttyGS%d (%p,%p) done!\n", port->port_num, tty, file); - wake_up_interruptible(&port->close_wait); + wake_up(&port->port.close_wait); exit: spin_unlock_irq(&port->port_lock); } @@ -850,7 +916,7 @@ static int gs_put_char(struct tty_struct *tty, unsigned char ch) unsigned long flags; int status; - pr_vdebug("gs_put_char: (%d,%p) char=0x%x, called from %p\n", + pr_vdebug("gs_put_char: (%d,%p) char=0x%x, called from %pf\n", port->port_num, tty, ch, __builtin_return_address(0)); spin_lock_irqsave(&port->port_lock, flags); @@ -911,15 +977,35 @@ static void gs_unthrottle(struct tty_struct *tty) { struct gs_port *port = tty->driver_data; unsigned long flags; - unsigned started = 0; spin_lock_irqsave(&port->port_lock, flags); - if (port->port_usb) - started = gs_start_rx(port); + if (port->port_usb) { + /* Kickstart read queue processing. We don't do xon/xoff, + * rts/cts, or other handshaking with the host, but if the + * read queue backs up enough we'll be NAKing OUT packets. + */ + tasklet_schedule(&port->push); + pr_vdebug(PREFIX "%d: unthrottle\n", port->port_num); + } spin_unlock_irqrestore(&port->port_lock, flags); +} - pr_vdebug("gs_unthrottle: ttyGS%d, %d packets\n", - port->port_num, started); +static int gs_break_ctl(struct tty_struct *tty, int duration) +{ + struct gs_port *port = tty->driver_data; + int status = 0; + struct gserial *gser; + + pr_vdebug("gs_break_ctl: ttyGS%d, send break (%d) \n", + port->port_num, duration); + + spin_lock_irq(&port->port_lock); + gser = port->port_usb; + if (gser && gser->send_break) + status = gser->send_break(gser, duration); + spin_unlock_irq(&port->port_lock); + + return status; } static const struct tty_operations gs_tty_ops = { @@ -931,136 +1017,48 @@ static const struct tty_operations gs_tty_ops = { .write_room = gs_write_room, .chars_in_buffer = gs_chars_in_buffer, .unthrottle = gs_unthrottle, + .break_ctl = gs_break_ctl, }; /*-------------------------------------------------------------------------*/ static struct tty_driver *gs_tty_driver; -static int __init +static int gs_port_alloc(unsigned port_num, struct usb_cdc_line_coding *coding) { struct gs_port *port; + int ret = 0; + + mutex_lock(&ports[port_num].lock); + if (ports[port_num].port) { + ret = -EBUSY; + goto out; + } port = kzalloc(sizeof(struct gs_port), GFP_KERNEL); - if (port == NULL) - return -ENOMEM; + if (port == NULL) { + ret = -ENOMEM; + goto out; + } + tty_port_init(&port->port); spin_lock_init(&port->port_lock); - init_waitqueue_head(&port->close_wait); init_waitqueue_head(&port->drain_wait); tasklet_init(&port->push, gs_rx_push, (unsigned long) port); INIT_LIST_HEAD(&port->read_pool); + INIT_LIST_HEAD(&port->read_queue); INIT_LIST_HEAD(&port->write_pool); port->port_num = port_num; port->port_line_coding = *coding; ports[port_num].port = port; - - return 0; -} - -/** - * gserial_setup - initialize TTY driver for one or more ports - * @g: gadget to associate with these ports - * @count: how many ports to support - * Context: may sleep - * - * The TTY stack needs to know in advance how many devices it should - * plan to manage. Use this call to set up the ports you will be - * exporting through USB. Later, connect them to functions based - * on what configuration is activated by the USB host; and disconnect - * them as appropriate. - * - * An example would be a two-configuration device in which both - * configurations expose port 0, but through different functions. - * One configuration could even expose port 1 while the other - * one doesn't. - * - * Returns negative errno or zero. - */ -int __init gserial_setup(struct usb_gadget *g, unsigned count) -{ - unsigned i; - struct usb_cdc_line_coding coding; - int status; - - if (count == 0 || count > N_PORTS) - return -EINVAL; - - gs_tty_driver = alloc_tty_driver(count); - if (!gs_tty_driver) - return -ENOMEM; - - gs_tty_driver->owner = THIS_MODULE; - gs_tty_driver->driver_name = "g_serial"; - gs_tty_driver->name = "ttyGS"; - /* uses dynamically assigned dev_t values */ - - gs_tty_driver->type = TTY_DRIVER_TYPE_SERIAL; - gs_tty_driver->subtype = SERIAL_TYPE_NORMAL; - gs_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; - gs_tty_driver->init_termios = tty_std_termios; - - /* 9600-8-N-1 ... matches defaults expected by "usbser.sys" on - * MS-Windows. Otherwise, most of these flags shouldn't affect - * anything unless we were to actually hook up to a serial line. - */ - gs_tty_driver->init_termios.c_cflag = - B9600 | CS8 | CREAD | HUPCL | CLOCAL; - gs_tty_driver->init_termios.c_ispeed = 9600; - gs_tty_driver->init_termios.c_ospeed = 9600; - - coding.dwDTERate = __constant_cpu_to_le32(9600); - coding.bCharFormat = 8; - coding.bParityType = USB_CDC_NO_PARITY; - coding.bDataBits = USB_CDC_1_STOP_BITS; - - tty_set_operations(gs_tty_driver, &gs_tty_ops); - - /* make devices be openable */ - for (i = 0; i < count; i++) { - mutex_init(&ports[i].lock); - status = gs_port_alloc(i, &coding); - if (status) { - count = i; - goto fail; - } - } - n_ports = count; - - /* export the driver ... */ - status = tty_register_driver(gs_tty_driver); - if (status) { - put_tty_driver(gs_tty_driver); - pr_err("%s: cannot register, err %d\n", - __func__, status); - goto fail; - } - - /* ... and sysfs class devices, so mdev/udev make /dev/ttyGS* */ - for (i = 0; i < count; i++) { - struct device *tty_dev; - - tty_dev = tty_register_device(gs_tty_driver, i, &g->dev); - if (IS_ERR(tty_dev)) - pr_warning("%s: no classdev for port %d, err %ld\n", - __func__, i, PTR_ERR(tty_dev)); - } - - pr_debug("%s: registered %d ttyGS* device%s\n", __func__, - count, (count == 1) ? "" : "s"); - - return status; -fail: - while (count--) - kfree(ports[count].port); - put_tty_driver(gs_tty_driver); - gs_tty_driver = NULL; - return status; +out: + mutex_unlock(&ports[port_num].lock); + return ret; } static int gs_closed(struct gs_port *port) @@ -1068,56 +1066,82 @@ static int gs_closed(struct gs_port *port) int cond; spin_lock_irq(&port->port_lock); - cond = (port->open_count == 0) && !port->openclose; + cond = (port->port.count == 0) && !port->openclose; spin_unlock_irq(&port->port_lock); return cond; } -/** - * gserial_cleanup - remove TTY-over-USB driver and devices - * Context: may sleep - * - * This is called to free all resources allocated by @gserial_setup(). - * Accordingly, it may need to wait until some open /dev/ files have - * closed. - * - * The caller must have issued @gserial_disconnect() for any ports - * that had previously been connected, so that there is never any - * I/O pending when it's called. - */ -void gserial_cleanup(void) +static void gserial_free_port(struct gs_port *port) +{ + tasklet_kill(&port->push); + /* wait for old opens to finish */ + wait_event(port->port.close_wait, gs_closed(port)); + WARN_ON(port->port_usb != NULL); + tty_port_destroy(&port->port); + kfree(port); +} + +void gserial_free_line(unsigned char port_num) { - unsigned i; struct gs_port *port; - if (!gs_tty_driver) + mutex_lock(&ports[port_num].lock); + if (WARN_ON(!ports[port_num].port)) { + mutex_unlock(&ports[port_num].lock); return; + } + port = ports[port_num].port; + ports[port_num].port = NULL; + mutex_unlock(&ports[port_num].lock); - /* start sysfs and /dev/ttyGS* node removal */ - for (i = 0; i < n_ports; i++) - tty_unregister_device(gs_tty_driver, i); - - for (i = 0; i < n_ports; i++) { - /* prevent new opens */ - mutex_lock(&ports[i].lock); - port = ports[i].port; - ports[i].port = NULL; - mutex_unlock(&ports[i].lock); + gserial_free_port(port); + tty_unregister_device(gs_tty_driver, port_num); +} +EXPORT_SYMBOL_GPL(gserial_free_line); - /* wait for old opens to finish */ - wait_event(port->close_wait, gs_closed(port)); +int gserial_alloc_line(unsigned char *line_num) +{ + struct usb_cdc_line_coding coding; + struct device *tty_dev; + int ret; + int port_num; - WARN_ON(port->port_usb != NULL); + coding.dwDTERate = cpu_to_le32(9600); + coding.bCharFormat = 8; + coding.bParityType = USB_CDC_NO_PARITY; + coding.bDataBits = USB_CDC_1_STOP_BITS; - kfree(port); + for (port_num = 0; port_num < MAX_U_SERIAL_PORTS; port_num++) { + ret = gs_port_alloc(port_num, &coding); + if (ret == -EBUSY) + continue; + if (ret) + return ret; + break; } - n_ports = 0; + if (ret) + return ret; - tty_unregister_driver(gs_tty_driver); - gs_tty_driver = NULL; + /* ... and sysfs class devices, so mdev/udev make /dev/ttyGS* */ + + tty_dev = tty_port_register_device(&ports[port_num].port->port, + gs_tty_driver, port_num, NULL); + if (IS_ERR(tty_dev)) { + struct gs_port *port; + pr_err("%s: failed to register tty for port %d, err %ld\n", + __func__, port_num, PTR_ERR(tty_dev)); - pr_debug("%s: cleaned up ttyGS* support\n", __func__); + ret = PTR_ERR(tty_dev); + port = ports[port_num].port; + ports[port_num].port = NULL; + gserial_free_port(port); + goto err; + } + *line_num = port_num; +err: + return ret; } +EXPORT_SYMBOL_GPL(gserial_alloc_line); /** * gserial_connect - notify TTY I/O glue that USB link is active @@ -1134,8 +1158,8 @@ void gserial_cleanup(void) * * Caller needs to have set up the endpoints and USB function in @dev * before calling this, as well as the appropriate (speed-specific) - * endpoint descriptors, and also have set up the TTY driver by calling - * @gserial_setup(). + * endpoint descriptors, and also have allocate @port_num by calling + * @gserial_alloc_line(). * * Returns negative errno or zero. * On success, ep->driver_data will be overwritten. @@ -1146,19 +1170,26 @@ int gserial_connect(struct gserial *gser, u8 port_num) unsigned long flags; int status; - if (!gs_tty_driver || port_num >= n_ports) + if (port_num >= MAX_U_SERIAL_PORTS) return -ENXIO; - /* we "know" gserial_cleanup() hasn't been called */ port = ports[port_num].port; + if (!port) { + pr_err("serial line %d not allocated.\n", port_num); + return -EINVAL; + } + if (port->port_usb) { + pr_err("serial line %d is in use.\n", port_num); + return -EBUSY; + } /* activate the endpoints */ - status = usb_ep_enable(gser->in, gser->in_desc); + status = usb_ep_enable(gser->in); if (status < 0) return status; gser->in->driver_data = port; - status = usb_ep_enable(gser->out, gser->out_desc); + status = usb_ep_enable(gser->out); if (status < 0) goto fail_out; gser->out->driver_data = port; @@ -1175,14 +1206,17 @@ int gserial_connect(struct gserial *gser, u8 port_num) /* REVISIT if waiting on "carrier detect", signal. */ - /* REVISIT for ACM, issue "network connection" status notification: - * connected if open_count, else disconnected. + /* if it's already open, start I/O ... and notify the serial + * protocol about open/close status (connect/disconnect). */ - - /* if it's already open, start I/O */ - if (port->open_count) { + if (port->port.count) { pr_debug("gserial_connect: start ttyGS%d\n", port->port_num); gs_start_io(port); + if (gser->connect) + gser->connect(gser); + } else { + if (gser->disconnect) + gser->disconnect(gser); } spin_unlock_irqrestore(&port->port_lock, flags); @@ -1194,7 +1228,7 @@ fail_out: gser->in->driver_data = NULL; return status; } - +EXPORT_SYMBOL_GPL(gserial_connect); /** * gserial_disconnect - notify TTY I/O glue that USB link is inactive * @gser: the function, on which gserial_connect() was called @@ -1222,10 +1256,10 @@ void gserial_disconnect(struct gserial *gser) port->port_usb = NULL; gser->ioport = NULL; - if (port->open_count > 0 || port->openclose) { + if (port->port.count > 0 || port->openclose) { wake_up_interruptible(&port->drain_wait); - if (port->port_tty) - tty_hangup(port->port_tty); + if (port->port.tty) + tty_hangup(port->port.tty); } spin_unlock_irqrestore(&port->port_lock, flags); @@ -1238,9 +1272,76 @@ void gserial_disconnect(struct gserial *gser) /* finally, free any unused/unusable I/O buffers */ spin_lock_irqsave(&port->port_lock, flags); - if (port->open_count == 0 && !port->openclose) + if (port->port.count == 0 && !port->openclose) gs_buf_free(&port->port_write_buf); - gs_free_requests(gser->out, &port->read_pool); - gs_free_requests(gser->in, &port->write_pool); + gs_free_requests(gser->out, &port->read_pool, NULL); + gs_free_requests(gser->out, &port->read_queue, NULL); + gs_free_requests(gser->in, &port->write_pool, NULL); + + port->read_allocated = port->read_started = + port->write_allocated = port->write_started = 0; + spin_unlock_irqrestore(&port->port_lock, flags); } +EXPORT_SYMBOL_GPL(gserial_disconnect); + +static int userial_init(void) +{ + unsigned i; + int status; + + gs_tty_driver = alloc_tty_driver(MAX_U_SERIAL_PORTS); + if (!gs_tty_driver) + return -ENOMEM; + + gs_tty_driver->driver_name = "g_serial"; + gs_tty_driver->name = PREFIX; + /* uses dynamically assigned dev_t values */ + + gs_tty_driver->type = TTY_DRIVER_TYPE_SERIAL; + gs_tty_driver->subtype = SERIAL_TYPE_NORMAL; + gs_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; + gs_tty_driver->init_termios = tty_std_termios; + + /* 9600-8-N-1 ... matches defaults expected by "usbser.sys" on + * MS-Windows. Otherwise, most of these flags shouldn't affect + * anything unless we were to actually hook up to a serial line. + */ + gs_tty_driver->init_termios.c_cflag = + B9600 | CS8 | CREAD | HUPCL | CLOCAL; + gs_tty_driver->init_termios.c_ispeed = 9600; + gs_tty_driver->init_termios.c_ospeed = 9600; + + tty_set_operations(gs_tty_driver, &gs_tty_ops); + for (i = 0; i < MAX_U_SERIAL_PORTS; i++) + mutex_init(&ports[i].lock); + + /* export the driver ... */ + status = tty_register_driver(gs_tty_driver); + if (status) { + pr_err("%s: cannot register, err %d\n", + __func__, status); + goto fail; + } + + pr_debug("%s: registered %d ttyGS* device%s\n", __func__, + MAX_U_SERIAL_PORTS, + (MAX_U_SERIAL_PORTS == 1) ? "" : "s"); + + return status; +fail: + put_tty_driver(gs_tty_driver); + gs_tty_driver = NULL; + return status; +} +module_init(userial_init); + +static void userial_cleanup(void) +{ + tty_unregister_driver(gs_tty_driver); + put_tty_driver(gs_tty_driver); + gs_tty_driver = NULL; +} +module_exit(userial_cleanup); + +MODULE_LICENSE("GPL"); |