Staging: quatech_usb2: vendor implementation of break_ctl
authorRichard Ash <richard@audacityteam.org>
Thu, 20 Aug 2009 10:24:49 +0000 (11:24 +0100)
committerGreg Kroah-Hartman <gregkh@suse.de>
Tue, 15 Sep 2009 19:01:36 +0000 (12:01 -0700)
This patch imports the implementation of the break_ctl, throttle and
unthrottle methods from the vendor driver into the staging driver. This
compiles but is not yet tested.

Signed-off-by: Richard Ash <richard@audacityteam.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/staging/quatech_usb2/quatech_usb2.c

index f71921998ce2591b2d6cb68c375ad1e69edfd368..b06e90d3cefc6b06d7999fd39842e591d659cdd9 100644 (file)
@@ -56,11 +56,11 @@ static int debug;
 #define QT2_GET_SET_UART                       0xc1
 #define QT2_HW_FLOW_CONTROL_MASK               0xc5
 #define QT2_SW_FLOW_CONTROL_MASK               0xc6
-#define QT2_SW_FLOW_CONTROL_DISABLE    0xc7
-/*#define QT_BREAK_CONTROL             0xc8
-#define QT_STOP_RECEIVE                        0xe0*/
-#define QT2_FLUSH_DEVICE               0xc4
-#define QT_GET_SET_QMCR                        0xe1
+#define QT2_SW_FLOW_CONTROL_DISABLE            0xc7
+#define QT2_BREAK_CONTROL                      0xc8
+#define QT2_STOP_RECEIVE                       0xe0
+#define QT2_FLUSH_DEVICE                       0xc4
+#define QT2_GET_SET_QMCR                       0xe1
 
 /* sorts of flush we can do on */
 #define QT2_FLUSH_RX                   0x00
@@ -138,31 +138,21 @@ static struct usb_driver quausb2_usb_driver = {
        .no_dynamic_id = 1,
 };
 
-/** structure in which to keep all the messy stuff that this driver needs
- * alongside the usb_serial_port structure
- * @param read_urb_busy Flag indicating that port->read_urb is in use
- * @param close_pending flag indicating that this port is in the process of
+/**
+ * quatech2_port: Structure in which to keep all the messy stuff that this
+ * driver needs alongside the usb_serial_port structure
+ * @read_urb_busy: Flag indicating that port->read_urb is in use
+ * @close_pending: flag indicating that this port is in the process of
  * being closed (and so no new reads / writes should be started).
- * @param shadowLSR Last received state of the line status register, holds the
+ * @shadowLSR: Last received state of the line status register, holds the
  * value of the line status flags from the port
- * @param shadowMSR Last received state of the modem status register, holds
+ * @shadowMSR: Last received state of the modem status register, holds
  * the value of the modem status received from the port
- * @param rcv_flush Flag indicating that a receive flush has occured on
+ * @rcv_flush: Flag indicating that a receive flush has occured on
  * the hardware.
- * @param xmit_flush Flag indicating that a transmit flush has been processed by
+ * @xmit_flush: Flag indicating that a transmit flush has been processed by
  * the hardware.
- * @param fifo_empty_flag
- * - Starts off true when port opened
- * - set false when a write is submitted to the driver
- * - as far as I can see not true again until device is re-opened.
- * - read in a number of places.
- * @param tx_fifo_room
- * - set to FIFO_DEPTH when port opened
- * - decremented by tc_pending_bytes when a new write is submitted.
- * - set to FIFO_DEPTH when "xmit_empty" is received from the device,
- * regardless of how many bytes were reported to have been sent (?)
- *
- * @param tx_pending_bytes Number of bytes waiting to be sent. This total
+ * @tx_pending_bytes: Number of bytes waiting to be sent. This total
  * includes the size (excluding header) of URBs that have been submitted but
  * have not yet been sent to to the device, and bytes that have been sent out
  * of the port but not yet reported sent by the "xmit_empty" messages (which
@@ -173,6 +163,10 @@ static struct usb_driver quausb2_usb_driver = {
  * each time a write urb is dispatched.
  * - is decremented each time a "transmit empty" message is received
  * by the driver in the data stream.
+ * @sem: Semaphore to lock access to this structure when we need to ensure that
+ * races don't occur to access bits of it.
+ * @open_count: The number of uses of the port currently having
+ * it open, i.e. the reference count.
  */
 struct quatech2_port {
        int     magic;
@@ -180,18 +174,16 @@ struct quatech2_port {
        bool    close_pending;
        __u8    shadowLSR;
        __u8    shadowMSR;
-       /*int   xmit_fifo_room_bytes;*/
        bool    rcv_flush;
        bool    xmit_flush;
-/*     bool    fifo_empty_flag;
-       int     tx_fifo_room;*/
        int     tx_pending_bytes;
+       struct semaphore        sem;
+       int     open_count;
 
        char    active;         /* someone has this device open */
        unsigned char           *xfer_to_tty_buffer;
        wait_queue_head_t       wait;
-       int     open_count;     /* number of times this port has been opened */
-       struct semaphore        sem;    /* locks this structure */
+
        __u8    shadowLCR;      /* last LCR value received */
        __u8    shadowMCR;      /* last MCR value received */
        char    RxHolding;
@@ -281,6 +273,8 @@ static int qt2_boxsethw_flowctl(struct usb_serial *serial,
 static int qt2_boxsetsw_flowctl(struct usb_serial *serial, __u16 UartNumber,
                unsigned char stop_char,  unsigned char start_char);
 static int qt2_boxunsetsw_flowctl(struct usb_serial *serial, __u16 UartNumber);
+static int qt2_boxstoprx(struct usb_serial *serial, unsigned short uart_number,
+                        unsigned short stop);
 
 /* implementation functions, roughly in order of use, are here */
 static int qt2_calc_num_ports(struct usb_serial *serial)
@@ -359,6 +353,8 @@ static int qt2_attach(struct usb_serial *serial)
                            __func__, i);
                        return -ENOMEM;
                }
+               /* initialise stuff in the structure */
+               qt2_port->open_count = 0;       /* port is not open */
                spin_lock_init(&qt2_port->lock);
                qt2_set_port_private(port, qt2_port);
        }
@@ -577,8 +573,6 @@ int qt2_open(struct tty_struct *tty, struct usb_serial_port *port)
                        port->bulk_out_size,
                        qt2_write_bulk_callback,
                        port);
-       /*port_extra->fifo_empty_flag = true;
-       port_extra->tx_fifo_room = FIFO_DEPTH;*/
        port_extra->tx_pending_bytes = 0;
 
        if (dev_extra->open_ports == 0) {
@@ -615,6 +609,8 @@ int qt2_open(struct tty_struct *tty, struct usb_serial_port *port)
 
        /* initialize our wait queues */
        init_waitqueue_head(&port_extra->wait);
+       /* increment the count of openings of this port by one */
+       port_extra->open_count++;
 
        /* remember to store dev_extra, port_extra and port0_extra back again at
         * end !*/
@@ -696,6 +692,9 @@ static void qt2_close(struct usb_serial_port *port)
        port->bulk_out_buffer = NULL;
        port->bulk_out_size = 0;
 
+       /* decrement the count of openings of this port by one */
+       port_extra->open_count--;
+       /* one less overall open as well */
        dev_extra->open_ports--;
        dbg("%s(): Exit, dev_extra->open_ports  = %d", __func__,
                dev_extra->open_ports);
@@ -1027,7 +1026,7 @@ static void qt2_set_termios(struct tty_struct *tty,
        /* Round to nearest divisor */
        if (((remainder * 2) >= baud) && (baud != 110))
                divisor++;
-       dbg("%s(): setting divisor = %d, QT2_MAX_BAUD_RATE = %d , LCR = 0x%x",
+       dbg("%s(): setting divisor = %d, QT2_MAX_BAUD_RATE = %d , LCR = %#.2x",
              __func__, divisor, QT2_MAX_BAUD_RATE, LCR_change_to);
 
        status = qt2_boxsetuart(serial, UartNumber, (unsigned short) divisor,
@@ -1156,6 +1155,131 @@ static int qt2_tiocmset(struct tty_struct *tty, struct file *file,
                return 0;
 }
 
+/** qt2_break - Turn BREAK on and off on the UARTs
+ */
+static void qt2_break(struct tty_struct *tty, int break_state)
+{
+       struct usb_serial_port *port = tty->driver_data; /* parent port */
+       struct usb_serial *serial = port->serial;       /* parent device */
+       struct quatech2_port *port_extra;       /* extra data for this port */
+       __u16 break_value;
+       unsigned int result;
+
+       port_extra = qt2_get_port_private(port);
+       if (!serial) {
+               dbg("%s(): port %d: no serial object", __func__, port->number);
+               return;
+       }
+
+       if (break_state == -1)
+               break_value = 1;
+       else
+               break_value = 0;
+       dbg("%s(): port %d, break_value %d", __func__, port->number,
+               break_value);
+
+       down(&port_extra->sem);
+       if (!port_extra->open_count) {
+               dbg("%s(): port not open", __func__);
+               goto exit;
+       }
+
+       result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+                               QT2_BREAK_CONTROL, 0x40, break_value,
+                               port->number, NULL, 0, 300);
+exit:
+       up(&port_extra->sem);
+       dbg("%s(): exit port %d", __func__, port->number);
+
+}
+/**
+ * qt2_throttle: - stop reading new data from the port
+ */
+static void qt2_throttle(struct tty_struct *tty)
+{
+       struct usb_serial_port *port = tty->driver_data;
+       struct usb_serial *serial = port->serial;
+       struct quatech2_port *port_extra;       /* extra data for this port */
+       dbg("%s(): port %d", __func__, port->number);
+
+       port_extra = qt2_get_port_private(port);
+       if (!serial) {
+               dbg("%s(): enter port %d no serial object", __func__,
+                     port->number);
+               return;
+       }
+
+       down(&port_extra->sem); /* lock structure */
+       if (!port_extra->open_count) {
+               dbg("%s(): port not open", __func__);
+               goto exit;
+       }
+       /* Send command to box to stop receiving stuff. This will stop this
+        * particular UART from filling the endpoint - in the multiport case the
+        * FPGA UART will handle any flow control implmented, but for the single
+        * port it's handed differently and we just quit submitting urbs
+        */
+       if (serial->dev->descriptor.idProduct != QUATECH_SSU2_100)
+               qt2_boxstoprx(serial, port->number, 1);
+
+       port->throttled = 1;
+exit:
+       up(&port_extra->sem);
+       dbg("%s(): port %d: setting port->throttled", __func__, port->number);
+       return;
+}
+
+/**
+ * qt2_unthrottle: - start receiving data through the port again after being
+ * throttled
+ */
+static void qt2_unthrottle(struct tty_struct *tty)
+{
+       struct usb_serial_port *port = tty->driver_data;
+       struct usb_serial *serial = port->serial;
+       struct quatech2_port *port_extra;       /* extra data for this port */
+       struct usb_serial_port *port0;  /* first port structure on device */
+       struct quatech2_dev *dev_extra;         /* extra data for the device */
+
+       if (!serial) {
+               dbg("%s() enter port %d no serial object!", __func__,
+                       port->number);
+               return;
+       }
+       dbg("%s(): enter port %d", __func__, port->number);
+       dev_extra = qt2_get_dev_private(serial);
+       port_extra = qt2_get_port_private(port);
+       port0 = serial->port[0]; /* get the first port's device structure */
+
+       down(&port_extra->sem);
+       if (!port_extra->open_count) {
+               dbg("%s(): port %d not open", __func__, port->number);
+               goto exit;
+       }
+
+       if (port->throttled != 0) {
+               dbg("%s(): port %d: unsetting port->throttled", __func__,
+                   port->number);
+               port->throttled = 0;
+               /* Send command to box to start receiving stuff */
+               if (serial->dev->descriptor.idProduct != QUATECH_SSU2_100) {
+                       qt2_boxstoprx(serial,  port->number, 0);
+               } else if (dev_extra->ReadBulkStopped == true) {
+                       usb_fill_bulk_urb(port0->read_urb, serial->dev,
+                               usb_rcvbulkpipe(serial->dev,
+                               port0->bulk_in_endpointAddress),
+                               port0->bulk_in_buffer,
+                               port0->bulk_in_size,
+                               qt2_read_bulk_callback,
+                               serial);
+               }
+       }
+exit:
+       up(&port_extra->sem);
+       dbg("%s(): exit port %d", __func__, port->number);
+       return;
+}
+
 /* internal, private helper functions for the driver */
 
 /* Power up the FPGA in the box to get it working */
@@ -1173,7 +1297,7 @@ static int qt2_boxpoweron(struct usb_serial *serial)
 }
 
 /*
- * qt2_boxsetQMCR Issue a QT_GET_SET_QMCR vendor-spcific request on the
+ * qt2_boxsetQMCR Issue a QT2_GET_SET_QMCR vendor-spcific request on the
  * default control pipe. If successful return the number of bytes written,
  * otherwise return a negative error number of the problem.
  */
@@ -1189,7 +1313,7 @@ static int qt2_boxsetQMCR(struct usb_serial *serial, __u16 Uart_Number,
                        Uart_Number, PortSettings);
 
        result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
-                               QT_GET_SET_QMCR, 0x40, PortSettings,
+                               QT2_GET_SET_QMCR, 0x40, PortSettings,
                                (__u16)Uart_Number, NULL, 0, 5000);
        return result;
 }
@@ -1388,7 +1512,7 @@ __func__);
 
        /* active is a usb_serial_port. It has a member port which is a
         * tty_port. From this we get a tty_struct pointer which is what we
-        * actually wanted, and keep it on tty_st */
+       * actually wanted, and keep it on         tty_st */
        tty_st = tty_port_tty_get(&active->port);
        if (!tty_st) {
                dbg("%s - bad tty pointer - exiting", __func__);
@@ -1457,7 +1581,7 @@ __func__);
                                        }
                                        /* Port change. If port open push
                                         * current data up to tty layer */
-                                       if (dev_extra->open_ports > 0)
+                                       if (active_extra->open_count > 0)
                                                tty_flip_buffer_push(tty_st);
 
                                        dbg("Port Change: new port = %d",
@@ -1798,6 +1922,22 @@ static int qt2_boxunsetsw_flowctl(struct usb_serial *serial, __u16 UartNumber)
                        0, 300);
 }
 
+/**
+ * qt2_boxstoprx - Start and stop reception of data by the FPGA UART in
+ * response to requests from the tty layer
+ * @serial: pointer to the usb_serial structure for the parent device
+ * @uart_number: which UART on the device we are addressing
+ * @stop: Whether to start or stop data reception. Set to 1 to stop data being
+ * received, and to 0 to start it being received.
+ */
+static int qt2_boxstoprx(struct usb_serial *serial, unsigned short uart_number,
+               unsigned short stop)
+{
+       return usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+               QT2_STOP_RECEIVE, 0x40, stop, uart_number, NULL, 0, 300);
+}
+
+
 /*
  * last things in file: stuff to register this driver into the generic
  * USB serial framework.
@@ -1817,12 +1957,12 @@ static struct usb_serial_driver quatech2_device = {
        .write = qt2_write,
        .write_room = qt2_write_room,
        .chars_in_buffer = qt2_chars_in_buffer,
-       /*.throttle = qt_throttle,
-       .unthrottle = qt_unthrottle,*/
+       .throttle = qt2_throttle,
+       .unthrottle = qt2_unthrottle,
        .calc_num_ports = qt2_calc_num_ports,
        .ioctl = qt2_ioctl,
        .set_termios = qt2_set_termios,
-       /*.break_ctl = qt_break,*/
+       .break_ctl = qt2_break,
        .tiocmget = qt2_tiocmget,
        .tiocmset = qt2_tiocmset,
        .attach = qt2_attach,