diff options
Diffstat (limited to 'drivers/usb/gadget/function/u_serial.c')
| -rw-r--r-- | drivers/usb/gadget/function/u_serial.c | 138 |
1 files changed, 119 insertions, 19 deletions
diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c index 6f68cbeeee7c..1cce5317181a 100644 --- a/drivers/usb/gadget/function/u_serial.c +++ b/drivers/usb/gadget/function/u_serial.c @@ -21,12 +21,15 @@ #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/slab.h> +#include <linux/string_choices.h> #include <linux/export.h> #include <linux/module.h> #include <linux/console.h> +#include <linux/kstrtox.h> #include <linux/kthread.h> #include <linux/workqueue.h> #include <linux/kfifo.h> +#include <linux/serial.h> #include "u_serial.h" @@ -81,6 +84,9 @@ #define WRITE_BUF_SIZE 8192 /* TX only */ #define GS_CONSOLE_BUF_SIZE 8192 +/* Prevents race conditions while accessing gser->ioport */ +static DEFINE_SPINLOCK(serial_port_lock); + /* console info */ struct gs_console { struct console console; @@ -122,6 +128,7 @@ struct gs_port { wait_queue_head_t close_wait; bool suspended; /* port suspended */ bool start_delayed; /* delay start when suspended */ + struct async_icount icount; /* REVISIT this state ... */ struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */ @@ -253,6 +260,7 @@ __acquires(&port->port_lock) break; } do_tty_wake = true; + port->icount.tx += len; req->length = len; list_del(&req->list); @@ -287,8 +295,8 @@ __acquires(&port->port_lock) break; } - if (do_tty_wake && port->port.tty) - tty_wakeup(port->port.tty); + if (do_tty_wake) + tty_port_tty_wakeup(&port->port); return status; } @@ -404,6 +412,7 @@ static void gs_rx_push(struct work_struct *work) size -= n; } + port->icount.rx += size; count = tty_insert_flip_string(&port->port, packet, size); if (count) @@ -565,17 +574,31 @@ static int gs_start_io(struct gs_port *port) gs_start_tx(port); /* Unblock any pending writes into our circular buffer, in case * we didn't in gs_start_tx() */ - tty_wakeup(port->port.tty); + tty_port_tty_wakeup(&port->port); } else { - gs_free_requests(ep, head, &port->read_allocated); - gs_free_requests(port->port_usb->in, &port->write_pool, - &port->write_allocated); + /* Free reqs only if we are still connected */ + if (port->port_usb) { + gs_free_requests(ep, head, &port->read_allocated); + gs_free_requests(port->port_usb->in, &port->write_pool, + &port->write_allocated); + } status = -EIO; } return status; } +static int gserial_wakeup_host(struct gserial *gser) +{ + struct usb_function *func = &gser->func; + struct usb_gadget *gadget = func->config->cdev->gadget; + + if (func->func_suspended) + return usb_func_wakeup(func); + else + return usb_gadget_wakeup(gadget); +} + /*-------------------------------------------------------------------------*/ /* TTY Driver */ @@ -726,17 +749,30 @@ exit: spin_unlock_irq(&port->port_lock); } -static int gs_write(struct tty_struct *tty, const unsigned char *buf, int count) +static ssize_t gs_write(struct tty_struct *tty, const u8 *buf, size_t count) { struct gs_port *port = tty->driver_data; unsigned long flags; + int ret = 0; + struct gserial *gser = port->port_usb; - pr_vdebug("gs_write: ttyGS%d (%p) writing %d bytes\n", + pr_vdebug("gs_write: ttyGS%d (%p) writing %zu bytes\n", port->port_num, tty, count); spin_lock_irqsave(&port->port_lock, flags); if (count) count = kfifo_in(&port->port_write_buf, buf, count); + + if (port->suspended) { + spin_unlock_irqrestore(&port->port_lock, flags); + ret = gserial_wakeup_host(gser); + if (ret) { + pr_debug("ttyGS%d: Remote wakeup failed:%d\n", port->port_num, ret); + return count; + } + spin_lock_irqsave(&port->port_lock, flags); + } + /* treat count == 0 as flush_chars() */ if (port->port_usb) gs_start_tx(port); @@ -745,7 +781,7 @@ static int gs_write(struct tty_struct *tty, const unsigned char *buf, int count) return count; } -static int gs_put_char(struct tty_struct *tty, unsigned char ch) +static int gs_put_char(struct tty_struct *tty, u8 ch) { struct gs_port *port = tty->driver_data; unsigned long flags; @@ -765,10 +801,22 @@ static void gs_flush_chars(struct tty_struct *tty) { struct gs_port *port = tty->driver_data; unsigned long flags; + int ret = 0; + struct gserial *gser = port->port_usb; pr_vdebug("gs_flush_chars: (%d,%p)\n", port->port_num, tty); spin_lock_irqsave(&port->port_lock, flags); + if (port->suspended) { + spin_unlock_irqrestore(&port->port_lock, flags); + ret = gserial_wakeup_host(gser); + if (ret) { + pr_debug("ttyGS%d: Remote wakeup failed:%d\n", port->port_num, ret); + return; + } + spin_lock_irqsave(&port->port_lock, flags); + } + if (port->port_usb) gs_start_tx(port); spin_unlock_irqrestore(&port->port_lock, flags); @@ -843,6 +891,23 @@ static int gs_break_ctl(struct tty_struct *tty, int duration) return status; } +static int gs_get_icount(struct tty_struct *tty, + struct serial_icounter_struct *icount) +{ + struct gs_port *port = tty->driver_data; + struct async_icount cnow; + unsigned long flags; + + spin_lock_irqsave(&port->port_lock, flags); + cnow = port->icount; + spin_unlock_irqrestore(&port->port_lock, flags); + + icount->rx = cnow.rx; + icount->tx = cnow.tx; + + return 0; +} + static const struct tty_operations gs_tty_ops = { .open = gs_open, .close = gs_close, @@ -853,6 +918,7 @@ static const struct tty_operations gs_tty_ops = { .chars_in_buffer = gs_chars_in_buffer, .unthrottle = gs_unthrottle, .break_ctl = gs_break_ctl, + .get_icount = gs_get_icount, }; /*-------------------------------------------------------------------------*/ @@ -912,8 +978,11 @@ static void __gs_console_push(struct gs_console *cons) } req->length = size; + + spin_unlock_irq(&cons->lock); if (usb_ep_queue(ep, req, GFP_ATOMIC)) req->length = 0; + spin_lock_irq(&cons->lock); } static void gs_console_work(struct work_struct *work) @@ -1070,7 +1139,7 @@ ssize_t gserial_set_console(unsigned char port_num, const char *page, size_t cou bool enable; int ret; - ret = strtobool(page, &enable); + ret = kstrtobool(page, &enable); if (ret) return ret; @@ -1374,8 +1443,10 @@ void gserial_disconnect(struct gserial *gser) if (!port) return; + spin_lock_irqsave(&serial_port_lock, flags); + /* tell the TTY glue not to do I/O here any more */ - spin_lock_irqsave(&port->port_lock, flags); + spin_lock(&port->port_lock); gs_console_disconnect(port); @@ -1390,7 +1461,8 @@ void gserial_disconnect(struct gserial *gser) tty_hangup(port->port.tty); } port->suspended = false; - spin_unlock_irqrestore(&port->port_lock, flags); + spin_unlock(&port->port_lock); + spin_unlock_irqrestore(&serial_port_lock, flags); /* disable endpoints, aborting down any active I/O */ usb_ep_disable(gser->out); @@ -1413,21 +1485,48 @@ EXPORT_SYMBOL_GPL(gserial_disconnect); void gserial_suspend(struct gserial *gser) { - struct gs_port *port = gser->ioport; + struct gs_port *port; unsigned long flags; - spin_lock_irqsave(&port->port_lock, flags); + spin_lock_irqsave(&serial_port_lock, flags); + port = gser->ioport; + + if (!port) { + spin_unlock_irqrestore(&serial_port_lock, flags); + return; + } + + if (port->write_busy || port->write_started) { + /* Wakeup to host if there are ongoing transfers */ + spin_unlock_irqrestore(&serial_port_lock, flags); + if (!gserial_wakeup_host(gser)) + return; + spin_lock_irqsave(&serial_port_lock, flags); + } + + spin_lock(&port->port_lock); + spin_unlock(&serial_port_lock); port->suspended = true; + port->start_delayed = true; spin_unlock_irqrestore(&port->port_lock, flags); } EXPORT_SYMBOL_GPL(gserial_suspend); void gserial_resume(struct gserial *gser) { - struct gs_port *port = gser->ioport; + struct gs_port *port; unsigned long flags; - spin_lock_irqsave(&port->port_lock, flags); + spin_lock_irqsave(&serial_port_lock, flags); + port = gser->ioport; + + if (!port) { + spin_unlock_irqrestore(&serial_port_lock, flags); + return; + } + + spin_lock(&port->port_lock); + spin_unlock(&serial_port_lock); port->suspended = false; if (!port->start_delayed) { spin_unlock_irqrestore(&port->port_lock, flags); @@ -1443,7 +1542,7 @@ void gserial_resume(struct gserial *gser) } EXPORT_SYMBOL_GPL(gserial_resume); -static int userial_init(void) +static int __init userial_init(void) { struct tty_driver *driver; unsigned i; @@ -1487,7 +1586,7 @@ static int userial_init(void) pr_debug("%s: registered %d ttyGS* device%s\n", __func__, MAX_U_SERIAL_PORTS, - (MAX_U_SERIAL_PORTS == 1) ? "" : "s"); + str_plural(MAX_U_SERIAL_PORTS)); return status; fail: @@ -1496,7 +1595,7 @@ fail: } module_init(userial_init); -static void userial_cleanup(void) +static void __exit userial_cleanup(void) { tty_unregister_driver(gs_tty_driver); tty_driver_kref_put(gs_tty_driver); @@ -1504,4 +1603,5 @@ static void userial_cleanup(void) } module_exit(userial_cleanup); +MODULE_DESCRIPTION("utilities for USB gadget \"serial port\"/TTY support"); MODULE_LICENSE("GPL"); |