// SPDX-License-Identifier: GPL-2.0 /* * usb-serial driver for Quatech USB 2 devices * * Copyright (C) 2012 Bill Pemberton (wfp5p@virginia.edu) * * These devices all have only 1 bulk in and 1 bulk out that is shared * for all serial ports. * */ #include #include #include #include #include #include #include #include #include #include #include #include /* default urb timeout for usb operations */ #define QT2_USB_TIMEOUT USB_CTRL_SET_TIMEOUT #define QT_OPEN_CLOSE_CHANNEL 0xca #define QT_SET_GET_DEVICE 0xc2 #define QT_SET_GET_REGISTER 0xc0 #define QT_GET_SET_PREBUF_TRIG_LVL 0xcc #define QT_SET_ATF 0xcd #define QT_TRANSFER_IN 0xc0 #define QT_HW_FLOW_CONTROL_MASK 0xc5 #define QT_SW_FLOW_CONTROL_MASK 0xc6 #define QT2_BREAK_CONTROL 0xc8 #define QT2_GET_SET_UART 0xc1 #define QT2_FLUSH_DEVICE 0xc4 #define QT2_GET_SET_QMCR 0xe1 #define QT2_QMCR_RS232 0x40 #define QT2_QMCR_RS422 0x10 #define SERIAL_CRTSCTS ((UART_MCR_RTS << 8) | UART_MSR_CTS) #define SERIAL_EVEN_PARITY (UART_LCR_PARITY | UART_LCR_EPAR) /* status bytes for the device */ #define QT2_CONTROL_BYTE 0x1b #define QT2_LINE_STATUS 0x00 /* following 1 byte is line status */ #define QT2_MODEM_STATUS 0x01 /* following 1 byte is modem status */ #define QT2_XMIT_HOLD 0x02 /* following 2 bytes are ?? */ #define QT2_CHANGE_PORT 0x03 /* following 1 byte is port to change to */ #define QT2_REC_FLUSH 0x04 /* no following info */ #define QT2_XMIT_FLUSH 0x05 /* no following info */ #define QT2_CONTROL_ESCAPE 0xff /* pass through previous 2 control bytes */ #define MAX_BAUD_RATE 921600 #define DEFAULT_BAUD_RATE 9600 #define QT2_READ_BUFFER_SIZE 512 /* size of read buffer */ #define QT2_WRITE_BUFFER_SIZE 512 /* size of write buffer */ #define QT2_WRITE_CONTROL_SIZE 5 /* control bytes used for a write */ #define DRIVER_DESC "Quatech 2nd gen USB to Serial Driver" #define USB_VENDOR_ID_QUATECH 0x061d #define QUATECH_SSU2_100 0xC120 /* RS232 single port */ #define QUATECH_DSU2_100 0xC140 /* RS232 dual port */ #define QUATECH_DSU2_400 0xC150 /* RS232/422/485 dual port */ #define QUATECH_QSU2_100 0xC160 /* RS232 four port */ #define QUATECH_QSU2_400 0xC170 /* RS232/422/485 four port */ #define QUATECH_ESU2_100 0xC1A0 /* RS232 eight port */ #define QUATECH_ESU2_400 0xC180 /* RS232/422/485 eight port */ struct qt2_device_detail { int product_id; int num_ports; }; #define QT_DETAILS(prod, ports) \ .product_id = (prod), \ .num_ports = (ports) static const struct qt2_device_detail qt2_device_details[] = { {QT_DETAILS(QUATECH_SSU2_100, 1)}, {QT_DETAILS(QUATECH_DSU2_400, 2)}, {QT_DETAILS(QUATECH_DSU2_100, 2)}, {QT_DETAILS(QUATECH_QSU2_400, 4)}, {QT_DETAILS(QUATECH_QSU2_100, 4)}, {QT_DETAILS(QUATECH_ESU2_400, 8)}, {QT_DETAILS(QUATECH_ESU2_100, 8)}, {QT_DETAILS(0, 0)} /* Terminating entry */ }; static const struct usb_device_id id_table[] = { {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU2_100)}, {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_100)}, {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_400)}, {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_100)}, {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_400)}, {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_100)}, {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_400)}, {} /* Terminating entry */ }; MODULE_DEVICE_TABLE(usb, id_table); struct qt2_serial_private { unsigned char current_port; /* current port for incoming data */ struct urb *read_urb; /* shared among all ports */ char *read_buffer; }; struct qt2_port_private { u8 device_port; spinlock_t urb_lock; bool urb_in_use; struct urb *write_urb; char *write_buffer; spinlock_t lock; u8 shadowLSR; u8 shadowMSR; struct usb_serial_port *port; }; static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch); static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch); static void qt2_write_bulk_callback(struct urb *urb); static void qt2_read_bulk_callback(struct urb *urb); static void qt2_release(struct usb_serial *serial) { struct qt2_serial_private *serial_priv; serial_priv = usb_get_serial_data(serial); usb_kill_urb(serial_priv->read_urb); usb_free_urb(serial_priv->read_urb); kfree(serial_priv->read_buffer); kfree(serial_priv); } static inline int calc_baud_divisor(int baudrate) { int divisor, rem; divisor = MAX_BAUD_RATE / baudrate; rem = MAX_BAUD_RATE % baudrate; /* Round to nearest divisor */ if (((rem * 2) >= baudrate) && (baudrate != 110)) divisor++; return divisor; } static inline int qt2_set_port_config(struct usb_device *dev, unsigned char port_number, u16 baudrate, u16 lcr) { int divisor = calc_baud_divisor(baudrate); u16 index = ((u16) (lcr << 8) | (u16) (port_number)); return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), QT2_GET_SET_UART, 0x40, divisor, index, NULL, 0, QT2_USB_TIMEOUT); } static inline int qt2_control_msg(struct usb_device *dev, u8 request, u16 data, u16 index) { return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request, 0x40, data, index, NULL, 0, QT2_USB_TIMEOUT); } static inline int qt2_getregister(struct usb_device *dev, u8 uart, u8 reg, u8 *data) { int ret; ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), QT_SET_GET_REGISTER, 0xc0, reg, uart, data, sizeof(*data), QT2_USB_TIMEOUT); if (ret < (int)sizeof(*data)) { if (ret >= 0) ret = -EIO; } return ret; } static inline int qt2_setregister(struct usb_device *dev, u8 uart, u8 reg, u16 data) { u16 value = (data << 8) | reg; return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), QT_SET_GET_REGISTER, 0x40, value, uart, NULL, 0, QT2_USB_TIMEOUT); } static inline int update_mctrl(struct qt2_port_private *port_priv, unsigned int set, unsigned int clear) { struct usb_serial_port *port = port_priv->port; struct usb_device *dev = port->serial->dev; unsigned urb_value; int status; if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) { dev_dbg(&port->dev, "update_mctrl - DTR|RTS not being set|cleared\n"); return 0; /* no change */ } clear &= ~set; /* 'set' takes precedence over 'clear' */ urb_value = 0; if (set & TIOCM_DTR) urb_value |= UART_MCR_DTR; if (set & TIOCM_RTS) urb_value |= UART_MCR_RTS; status = qt2_setregister(dev, port_priv->device_port, UART_MCR, urb_value); if (status < 0) dev_err(&port->dev, "update_mctrl - Error from MODEM_CTRL urb: %i\n", status); return status; } static int qt2_calc_num_ports(struct usb_serial *serial, struct usb_serial_endpoints *epds) { struct qt2_device_detail d; int i; for (i = 0; d = qt2_device_details[i], d.product_id != 0; i++) { if (d.product_id == le16_to_cpu(serial->dev->descriptor.idProduct)) return d.num_ports; } /* we didn't recognize the device */ dev_err(&serial->dev->dev, "don't know the number of ports, assuming 1\n"); return 1; } static void qt2_set_termios(struct tty_struct *tty, struct usb_serial_port *port, const struct ktermios *old_termios) { struct usb_device *dev = port->serial->dev; struct qt2_port_private *port_priv; struct ktermios *termios = &tty->termios; u16 baud; unsigned int cflag = termios->c_cflag; u16 new_lcr = 0; int status; port_priv = usb_get_serial_port_data(port); if (cflag & PARENB) { if (cflag & PARODD) new_lcr |= UART_LCR_PARITY; else new_lcr |= SERIAL_EVEN_PARITY; } new_lcr |= UART_LCR_WLEN(tty_get_char_size(cflag)); baud = tty_get_baud_rate(tty); if (!baud) baud = 9600; status = qt2_set_port_config(dev, port_priv->device_port, baud, new_lcr); if (status < 0) dev_err(&port->dev, "%s - qt2_set_port_config failed: %i\n", __func__, status); if (cflag & CRTSCTS) status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK, SERIAL_CRTSCTS, port_priv->device_port); else status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK, 0, port_priv->device_port); if (status < 0) dev_err(&port->dev, "%s - set HW flow control failed: %i\n", __func__, status); if (I_IXOFF(tty) || I_IXON(tty)) { u16 x = ((u16) (START_CHAR(tty) << 8) | (u16) (STOP_CHAR(tty))); status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK, x, port_priv->device_port); } else status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK, 0, port_priv->device_port); if (status < 0) dev_err(&port->dev, "%s - set SW flow control failed: %i\n", __func__, status); } static int qt2_open(struct tty_struct *tty, struct usb_serial_port *port) { struct usb_serial *serial; struct qt2_port_private *port_priv; u8 *data; u16 device_port; int status; unsigned long flags; device_port = port->port_number; serial = port->serial; port_priv = usb_get_serial_port_data(port); /* set the port to RS232 mode */ status = qt2_control_msg(serial->dev, QT2_GET_SET_QMCR, QT2_QMCR_RS232, device_port); if (status < 0) { dev_err(&port->dev, "%s failed to set RS232 mode for port %i error %i\n", __func__, device_port, status); return status; } data = kzalloc(2, GFP_KERNEL); if (!data) return -ENOMEM; /* open the port */ status = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0), QT_OPEN_CLOSE_CHANNEL, 0xc0, 0, device_port, data, 2, QT2_USB_TIMEOUT); if (status < 2) { dev_err(&port->dev, "%s - open port failed %i\n", __func__, status); if (status >= 0) status = -EIO; kfree(data); return status; } spin_lock_irqsave(&port_priv->lock, flags); port_priv->shadowLSR = data[0]; port_priv->shadowMSR = data[1]; spin_unlock_irqrestore(&port_priv->lock, flags); kfree(data); /* set to default speed and 8bit word size */ status = qt2_set_port_config(serial->dev, device_port, DEFAULT_BAUD_RATE, UART_LCR_WLEN8); if (status < 0) { dev_err(&port->dev, "%s - initial setup failed (%i)\n", __func__, device_port); return status; } port_priv->device_port = (u8) device_port; if (tty) qt2_set_termios(tty, port, &tty->termios); return 0; } static void qt2_close(struct usb_serial_port *port) { struct usb_serial *serial; struct qt2_port_private *port_priv; int i; serial = port->serial; port_priv = usb_get_serial_port_data(port); usb_kill_urb(port_priv->write_urb); /* flush the port transmit buffer */ i = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), QT2_FLUSH_DEVICE, 0x40, 1, port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT); if (i < 0) dev_err(&port->dev, "%s - transmit buffer flush failed: %i\n", __func__, i); /* flush the port receive buffer */ i = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), QT2_FLUSH_DEVICE, 0x40, 0, port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT); if (i < 0) dev_err(&port->dev, "%s - receive buffer flush failed: %i\n", __func__, i); /* close the port */ i = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), QT_OPEN_CLOSE_CHANNEL, 0x40, 0, port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT); if (i < 0) dev_err(&port->dev, "%s - close port failed %i\n", __func__, i); } static void qt2_disconnect(struct usb_serial *serial) { struct qt2_serial_private *serial_priv = usb_get_serial_data(serial); usb_kill_urb(serial_priv->read_urb); } static void qt2_process_status(struct usb_serial_port *port, unsigned char *ch) { switch (*ch) { case QT2_LINE_STATUS: qt2_update_lsr(port, ch + 1); break; case QT2_MODEM_STATUS: qt2_update_msr(port, ch + 1); break; } } static void qt2_process_read_urb(struct urb *urb) { struct usb_serial *serial; struct qt2_serial_private *serial_priv; struct usb_serial_port *port; bool escapeflag; unsigned char *ch; int i; unsigned char newport; int len = urb->actual_length; if (!len) return; ch = urb->transfer_buffer; serial = urb->context; serial_priv = usb_get_serial_data(serial); port = serial->port[serial_priv->current_port]; for (i = 0; i < urb->actual_length; i++) { ch = (unsigned char *)urb->transfer_buffer + i; if ((i <= (len - 3)) && (*ch == QT2_CONTROL_BYTE) && (*(ch + 1) == QT2_CONTROL_BYTE)) { escapeflag = false; switch (*(ch + 2)) { case QT2_LINE_STATUS: case QT2_MODEM_STATUS: if (i > (len - 4)) { dev_warn(&port->dev, "%s - status message too short\n", __func__); break; } qt2_process_status(port, ch + 2); i += 3; escapeflag = true; break; case QT2_XMIT_HOLD: if (i > (len - 5)) { dev_warn(&port->dev, "%s - xmit_empty message too short\n", __func__); break; } /* bytes_written = (ch[1] << 4) + ch[0]; */ i += 4; escapeflag = true; break; case QT2_CHANGE_PORT: if (i > (len - 4)) { dev_warn(&port->dev, "%s - change_port message too short\n", __func__); break; } tty_flip_buffer_push(&port->port); newport = *(ch + 3); if (newport > serial->num_ports) { dev_err(&port->dev, "%s - port change to invalid port: %i\n", __func__, newport); break; } serial_priv->current_port = newport; port = serial->port[serial_priv->current_port]; i += 3; escapeflag = true; break; case QT2_REC_FLUSH: case QT2_XMIT_FLUSH: i += 2; escapeflag = true; break; case QT2_CONTROL_ESCAPE: tty_insert_flip_string(&port->port, ch, 2); i += 2; escapeflag = true; break; default: dev_warn(&port->dev, "%s - unsupported command %i\n", __func__, *(ch + 2)); break; } if (escapeflag) continue; } tty_insert_flip_char(&port->port, *ch, TTY_NORMAL); } tty_flip_buffer_push(&port->port); } static void qt2_write_bulk_callback(struct urb *urb) { struct usb_serial_port *port; struct qt2_port_private *port_priv; unsigned long flags; port = urb->context; port_priv = usb_get_serial_port_data(port); spin_lock_irqsave(&port_priv->urb_lock, flags); port_priv->urb_in_use = false; usb_serial_port_softint(port); spin_unlock_irqrestore(&port_priv->urb_lock, flags); } static void qt2_read_bulk_callback(struct urb *urb) { struct usb_serial *serial = urb->context; int status; if (urb->status) { dev_warn(&serial->dev->dev, "%s - non-zero urb status: %i\n", __func__, urb->status); return; } qt2_process_read_urb(urb); status = usb_submit_urb(urb, GFP_ATOMIC); if (status != 0) dev_err(&serial->dev->dev, "%s - resubmit read urb failed: %i\n", __func__, status); } static int qt2_setup_urbs(struct usb_serial *serial) { struct usb_serial_port *port0; struct qt2_serial_private *serial_priv; int status; port0 = serial->port[0]; serial_priv = usb_get_serial_data(serial); serial_priv->read_urb = usb_alloc_urb(0, GFP_KERNEL); if (!serial_priv->read_urb) return -ENOMEM; usb_fill_bulk_urb(serial_priv->read_urb, serial->dev, usb_rcvbulkpipe(serial->dev, port0->bulk_in_endpointAddress), serial_priv->read_buffer, QT2_READ_BUFFER_SIZE, qt2_read_bulk_callback, serial); status = usb_submit_urb(serial_priv->read_urb, GFP_KERNEL); if (status != 0) { dev_err(&serial->dev->dev, "%s - submit read urb failed %i\n", __func__, status); usb_free_urb(serial_priv->read_urb); return status; } return 0; } static int qt2_attach(struct usb_serial *serial) { struct qt2_serial_private *serial_priv; int status; /* power on unit */ status = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), 0xc2, 0x40, 0x8000, 0, NULL, 0, QT2_USB_TIMEOUT); if (status < 0) { dev_err(&serial->dev->dev, "%s - failed to power on unit: %i\n", __func__, status); return status; } serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL); if (!serial_priv) return -ENOMEM; serial_priv->read_buffer = kmalloc(QT2_READ_BUFFER_SIZE, GFP_KERNEL); if (!serial_priv->read_buffer) { status = -ENOMEM; goto err_buf; } usb_set_serial_data(serial, serial_priv); status = qt2_setup_urbs(serial); if (status != 0) goto attach_failed; return 0; attach_failed: kfree(serial_priv->read_buffer); err_buf: kfree(serial_priv); return status; } static int qt2_port_probe(struct usb_serial_port *port) { struct usb_serial *serial = port->serial; struct qt2_port_private *port_priv; u8 bEndpointAddress; port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL); if (!port_priv) return -ENOMEM; spin_lock_init(&port_priv->lock); spin_lock_init(&port_priv->urb_lock); port_priv->port = port; port_priv->write_buffer = kmalloc(QT2_WRITE_BUFFER_SIZE, GFP_KERNEL); if (!port_priv->write_buffer) goto err_buf; port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL); if (!port_priv->write_urb) goto err_urb; bEndpointAddress = serial->port[0]->bulk_out_endpointAddress; usb_fill_bulk_urb(port_priv->write_urb, serial->dev, usb_sndbulkpipe(serial->dev, bEndpointAddress), port_priv->write_buffer, QT2_WRITE_BUFFER_SIZE, qt2_write_bulk_callback, port); usb_set_serial_port_data(port, port_priv); return 0; err_urb: kfree(port_priv->write_buffer); err_buf: kfree(port_priv); return -ENOMEM; } static void qt2_port_remove(struct usb_serial_port *port) { struct qt2_port_private *port_priv; port_priv = usb_get_serial_port_data(port); usb_free_urb(port_priv->write_urb); kfree(port_priv->write_buffer); kfree(port_priv); } static int qt2_tiocmget(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; struct usb_device *dev = port->serial->dev; struct qt2_port_private *port_priv = usb_get_serial_port_data(port); u8 *d; int r; d = kzalloc(2, GFP_KERNEL); if (!d) return -ENOMEM; r = qt2_getregister(dev, port_priv->device_port, UART_MCR, d); if (r < 0) goto mget_out; r = qt2_getregister(dev, port_priv->device_port, UART_MSR, d + 1); if (r < 0) goto mget_out; r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) | (d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) | (d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) | (d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) | (d[1] & UART_MSR_RI ? TIOCM_RI : 0) | (d[1] & UART_MSR_DSR ? TIOCM_DSR : 0); mget_out: kfree(d); return r; } static int qt2_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear) { struct qt2_port_private *port_priv; port_priv = usb_get_serial_port_data(tty->driver_data); return update_mctrl(port_priv, set, clear); } static int qt2_break_ctl(struct tty_struct *tty, int break_state) { struct usb_serial_port *port = tty->driver_data; struct qt2_port_private *port_priv; int status; u16 val; port_priv = usb_get_serial_port_data(port); val = (break_state == -1) ? 1 : 0; status = qt2_control_msg(port->serial->dev, QT2_BREAK_CONTROL, val, port_priv->device_port); if (status < 0) { dev_warn(&port->dev, "%s - failed to send control message: %i\n", __func__, status); return status; } return 0; } static void qt2_dtr_rts(struct usb_serial_port *port, int on) { struct usb_device *dev = port->serial->dev; struct qt2_port_private *port_priv = usb_get_serial_port_data(port); /* Disable flow control */ if (!on) { if (qt2_setregister(dev, port_priv->device_port, UART_MCR, 0) < 0) dev_warn(&port->dev, "error from flowcontrol urb\n"); } /* drop RTS and DTR */ if (on) update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0); else update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS); } static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch) { struct qt2_port_private *port_priv; u8 newMSR = (u8) *ch; unsigned long flags; /* May be called from qt2_process_read_urb() for an unbound port. */ port_priv = usb_get_serial_port_data(port); if (!port_priv) return; spin_lock_irqsave(&port_priv->lock, flags); port_priv->shadowMSR = newMSR; spin_unlock_irqrestore(&port_priv->lock, flags); if (newMSR & UART_MSR_ANY_DELTA) { /* update input line counters */ if (newMSR & UART_MSR_DCTS) port->icount.cts++; if (newMSR & UART_MSR_DDSR) port->icount.dsr++; if (newMSR & UART_MSR_DDCD) port->icount.dcd++; if (newMSR & UART_MSR_TERI) port->icount.rng++; wake_up_interruptible(&port->port.delta_msr_wait); } } static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch) { struct qt2_port_private *port_priv; struct async_icount *icount; unsigned long flags; u8 newLSR = (u8) *ch; /* May be called from qt2_process_read_urb() for an unbound port. */ port_priv = usb_get_serial_port_data(port); if (!port_priv) return; if (newLSR & UART_LSR_BI) newLSR &= (u8) (UART_LSR_OE | UART_LSR_BI); spin_lock_irqsave(&port_priv->lock, flags); port_priv->shadowLSR = newLSR; spin_unlock_irqrestore(&port_priv->lock, flags); icount = &port->icount; if (newLSR & UART_LSR_BRK_ERROR_BITS) { if (newLSR & UART_LSR_BI) icount->brk++; if (newLSR & UART_LSR_OE) icount->overrun++; if (newLSR & UART_LSR_PE) icount->parity++; if (newLSR & UART_LSR_FE) icount->frame++; } } static unsigned int qt2_write_room(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; struct qt2_port_private *port_priv; unsigned long flags; unsigned int r; port_priv = usb_get_serial_port_data(port); spin_lock_irqsave(&port_priv->urb_lock, flags); if (port_priv->urb_in_use) r = 0; else r = QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE; spin_unlock_irqrestore(&port_priv->urb_lock, flags); return r; } static int qt2_write(struct tty_struct *tty, struct usb_serial_port *port, const unsigned char *buf, int count) { struct qt2_port_private *port_priv; struct urb *write_urb; unsigned char *data; unsigned long flags; int status; int bytes_out = 0; port_priv = usb_get_serial_port_data(port); if (port_priv->write_urb == NULL) { dev_err(&port->dev, "%s - no output urb\n", __func__); return 0; } write_urb = port_priv->write_urb; count = min(count, QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE); data = write_urb->transfer_buffer; spin_lock_irqsave(&port_priv->urb_lock, flags); if (port_priv->urb_in_use) { dev_err(&port->dev, "qt2_write - urb is in use\n"); goto write_out; } *data++ = QT2_CONTROL_BYTE; *data++ = QT2_CONTROL_BYTE; *data++ = port_priv->device_port; put_unaligned_le16(count, data); data += 2; memcpy(data, buf, count); write_urb->transfer_buffer_length = count + QT2_WRITE_CONTROL_SIZE; status = usb_submit_urb(write_urb, GFP_ATOMIC); if (status == 0) { port_priv->urb_in_use = true; bytes_out += count; } write_out: spin_unlock_irqrestore(&port_priv->urb_lock, flags); return bytes_out; } static struct usb_serial_driver qt2_device = { .driver = { .name = "quatech-serial", }, .description = DRIVER_DESC, .id_table = id_table, .open = qt2_open, .close = qt2_close, .write = qt2_write, .write_room = qt2_write_room, .calc_num_ports = qt2_calc_num_ports, .attach = qt2_attach, .release = qt2_release, .disconnect = qt2_disconnect, .port_probe = qt2_port_probe, .port_remove = qt2_port_remove, .dtr_rts = qt2_dtr_rts, .break_ctl = qt2_break_ctl, .tiocmget = qt2_tiocmget, .tiocmset = qt2_tiocmset, .tiocmiwait = usb_serial_generic_tiocmiwait, .get_icount = usb_serial_generic_get_icount, .set_termios = qt2_set_termios, }; static struct usb_serial_driver *const serial_drivers[] = { &qt2_device, NULL }; module_usb_serial_driver(serial_drivers, id_table); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL v2");