USB: opticon: add rts and cts support

Add support for RTS and CTS line status

Signed-off-by: Martin Jansen <martin.jansen@opticon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 112 insertions, 44 deletions

diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c
index eda1f9266c4e..ce82396fc4e8 100644
--- a/drivers/usb/serial/opticon.c
+++ b/drivers/usb/serial/opticon.c
@@ -1,6 +1,7 @@
 /*
  * Opticon USB barcode to serial driver
  *
+ * Copyright (C) 2011 Martin Jansen <martin.jansen@opticon.com>
  * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de>
  * Copyright (C) 2008 - 2009 Novell Inc.
  *
@@ -21,6 +22,16 @@
 #include <linux/usb/serial.h>
 #include <linux/uaccess.h>
 
+#define CONTROL_RTS                     0x02
+#define RESEND_CTS_STATE        0x03
+
+/* max number of write urbs in flight */
+#define URB_UPPER_LIMIT 8
+
+/* This driver works for the Opticon 1D barcode reader
+ * an examples of 1D barcode types are EAN, UPC, Code39, IATA etc.. */
+#define DRIVER_DESC     "Opticon USB barcode to serial driver (1D)"
+
 static int debug;
 
 static const struct usb_device_id id_table[] = {
@@ -42,13 +53,13 @@ struct opticon_private {
         bool throttled;
         bool actually_throttled;
         bool rts;
+        bool cts;
         int outstanding_urbs;
 };
 
-/* max number of write urbs in flight */
-#define URB_UPPER_LIMIT 4
 
-static void opticon_bulk_callback(struct urb *urb)
+
+static void opticon_read_bulk_callback(struct urb *urb)
 {
         struct opticon_private *priv = urb->context;
         unsigned char *data = urb->transfer_buffer;
@@ -57,6 +68,7 @@ static void opticon_bulk_callback(struct urb *urb)
         struct tty_struct *tty;
         int result;
         int data_length;
+        unsigned long flags;
 
         dbg("%s - port %d", __func__, port->number);
 
@@ -87,10 +99,10 @@ static void opticon_bulk_callback(struct urb *urb)
                  * Data from the device comes with a 2 byte header:
                  *
                  * <0x00><0x00>data...
-                 *      This is real data to be sent to the tty layer
+                 *      This is real data to be sent to the tty layer
                  * <0x00><0x01)level
-                 *      This is a RTS level change, the third byte is the RTS
-                 *      value (0 for low, 1 for high).
+                 *      This is a CTS level change, the third byte is the CTS
+                 *      value (0 for low, 1 for high).
                  */
                 if ((data[0] == 0x00) && (data[1] == 0x00)) {
                         /* real data, send it to the tty layer */
@@ -103,10 +115,13 @@ static void opticon_bulk_callback(struct urb *urb)
                         }
                 } else {
                         if ((data[0] == 0x00) && (data[1] == 0x01)) {
+                                spin_lock_irqsave(&priv->lock, flags);
+                                /* CTS status infomation package */
                                 if (data[2] == 0x00)
-                                        priv->rts = false;
+                                        priv->cts = false;
                                 else
-                                        priv->rts = true;
+                                        priv->cts = true;
+                                spin_unlock_irqrestore(&priv->lock, flags);
                         } else {
                                 dev_dbg(&priv->udev->dev,
                                         "Unknown data packet received from the device:"
@@ -129,7 +144,7 @@ exit:
                                   usb_rcvbulkpipe(priv->udev,
                                                   priv->bulk_address),
                                   priv->bulk_in_buffer, priv->buffer_size,
-                                  opticon_bulk_callback, priv);
+                                  opticon_read_bulk_callback, priv);
                 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
                 if (result)
                         dev_err(&port->dev,
@@ -140,6 +155,24 @@ exit:
         spin_unlock(&priv->lock);
 }
 
+static int send_control_msg(struct usb_serial_port *port, u8 requesttype,
+                                u8 val)
+{
+        struct usb_serial *serial = port->serial;
+        int retval;
+        u8 buffer[2];
+
+        buffer[0] = val;
+        /* Send the message to the vendor control endpoint
+         * of the connected device */
+        retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+                                requesttype,
+                                USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+                                0, 0, buffer, 1, 0);
+
+        return retval;
+}
+
 static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
 {
         struct opticon_private *priv = usb_get_serial_data(port->serial);
@@ -152,19 +185,30 @@ static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
         priv->throttled = false;
         priv->actually_throttled = false;
         priv->port = port;
+        priv->rts = false;
         spin_unlock_irqrestore(&priv->lock, flags);
 
-        /* Start reading from the device */
+        /* Clear RTS line */
+        send_control_msg(port, CONTROL_RTS, 0);
+
+        /* Setup the read URB and start reading from the device */
         usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
                           usb_rcvbulkpipe(priv->udev,
                                           priv->bulk_address),
                           priv->bulk_in_buffer, priv->buffer_size,
-                          opticon_bulk_callback, priv);
+                          opticon_read_bulk_callback, priv);
+
+        /* clear the halt status of the enpoint */
+        usb_clear_halt(priv->udev, priv->bulk_read_urb->pipe);
+
         result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
         if (result)
                 dev_err(&port->dev,
                         "%s - failed resubmitting read urb, error %d\n",
                         __func__, result);
+        /* Request CTS line state, sometimes during opening the current
+         * CTS state can be missed. */
+        send_control_msg(port, RESEND_CTS_STATE, 1);
         return result;
 }
 
@@ -178,7 +222,7 @@ static void opticon_close(struct usb_serial_port *port)
         usb_kill_urb(priv->bulk_read_urb);
 }
 
-static void opticon_write_bulk_callback(struct urb *urb)
+static void opticon_write_control_callback(struct urb *urb)
 {
         struct opticon_private *priv = urb->context;
         int status = urb->status;
@@ -210,6 +254,7 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
         unsigned char *buffer;
         unsigned long flags;
         int status;
+        struct usb_ctrlrequest *dr;
 
         dbg("%s - port %d", __func__, port->number);
 
@@ -226,6 +271,7 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
         if (!buffer) {
                 dev_err(&port->dev, "out of memory\n");
                 count = -ENOMEM;
+
                 goto error_no_buffer;
         }
 
@@ -240,35 +286,28 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 
         usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);
 
-        if (port->bulk_out_endpointAddress) {
-                usb_fill_bulk_urb(urb, serial->dev,
-                                  usb_sndbulkpipe(serial->dev,
-                                                  port->bulk_out_endpointAddress),
-                                  buffer, count, opticon_write_bulk_callback, priv);
-        } else {
-                struct usb_ctrlrequest *dr;
-
-                dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
-                if (!dr)
-                        return -ENOMEM;
-
-                dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT;
-                dr->bRequest = 0x01;
-                dr->wValue = 0;
-                dr->wIndex = 0;
-                dr->wLength = cpu_to_le16(count);
-
-                usb_fill_control_urb(urb, serial->dev,
-                        usb_sndctrlpipe(serial->dev, 0),
-                        (unsigned char *)dr, buffer, count,
-                        opticon_write_bulk_callback, priv);
-        }
+        /* The conncected devices do not have a bulk write endpoint,
+         * to transmit data to de barcode device the control endpoint is used */
+        dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
+        if (!dr)
+                return -ENOMEM;
+
+        dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT;
+        dr->bRequest = 0x01;
+        dr->wValue = 0;
+        dr->wIndex = 0;
+        dr->wLength = cpu_to_le16(count);
+
+        usb_fill_control_urb(urb, serial->dev,
+                usb_sndctrlpipe(serial->dev, 0),
+                (unsigned char *)dr, buffer, count,
+                opticon_write_control_callback, priv);
 
         /* send it down the pipe */
         status = usb_submit_urb(urb, GFP_ATOMIC);
         if (status) {
                 dev_err(&port->dev,
-                   "%s - usb_submit_urb(write bulk) failed with status = %d\n",
+                "%s - usb_submit_urb(write endpoint) failed status = %d\n",
                                                         __func__, status);
                 count = status;
                 goto error;
@@ -360,16 +399,49 @@ static int opticon_tiocmget(struct tty_struct *tty, struct file *file)
         int result = 0;
 
         dbg("%s - port %d", __func__, port->number);
+        if (!usb_get_intfdata(port->serial->interface))
+                return -ENODEV;
 
         spin_lock_irqsave(&priv->lock, flags);
         if (priv->rts)
-                result = TIOCM_RTS;
+                result |= TIOCM_RTS;
+        if (priv->cts)
+                result |= TIOCM_CTS;
         spin_unlock_irqrestore(&priv->lock, flags);
 
         dbg("%s - %x", __func__, result);
         return result;
 }
 
+static int opticon_tiocmset(struct tty_struct *tty, struct file *file,
+                           unsigned int set, unsigned int clear)
+{
+        struct usb_serial_port *port = tty->driver_data;
+        struct opticon_private *priv = usb_get_serial_data(port->serial);
+        unsigned long flags;
+        bool rts;
+        bool changed = false;
+
+        if (!usb_get_intfdata(port->serial->interface))
+                return -ENODEV;
+        /* We only support RTS so we only handle that */
+        spin_lock_irqsave(&priv->lock, flags);
+
+        rts = priv->rts;
+        if (set & TIOCM_RTS)
+                priv->rts = true;
+        if (clear & TIOCM_RTS)
+                priv->rts = false;
+        changed = rts ^ priv->rts;
+        spin_unlock_irqrestore(&priv->lock, flags);
+
+        if (!changed)
+                return 0;
+
+        /* Send the new RTS state to the connected device */
+        return send_control_msg(port, CONTROL_RTS, !rts);
+}
+
 static int get_serial_info(struct opticon_private *priv,
                            struct serial_struct __user *serial)
 {
@@ -431,6 +503,7 @@ static int opticon_startup(struct usb_serial *serial)
         priv->serial = serial;
         priv->port = serial->port[0];
         priv->udev = serial->dev;
+        priv->outstanding_urbs = 0;     /* Init the outstanding urbs */
 
         /* find our bulk endpoint */
         intf = serial->interface->altsetting;
@@ -456,13 +529,6 @@ static int opticon_startup(struct usb_serial *serial)
 
                 priv->bulk_address = endpoint->bEndpointAddress;
 
-                /* set up our bulk urb */
-                usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
-                                  usb_rcvbulkpipe(priv->udev,
-                                                  endpoint->bEndpointAddress),
-                                  priv->bulk_in_buffer, priv->buffer_size,
-                                  opticon_bulk_callback, priv);
-
                 bulk_in_found = true;
                 break;
                 }
@@ -558,6 +624,7 @@ static struct usb_serial_driver opticon_device = {
         .unthrottle =           opticon_unthrottle,
         .ioctl =                opticon_ioctl,
         .tiocmget =             opticon_tiocmget,
+        .tiocmset =             opticon_tiocmset,
 };
 
 static int __init opticon_init(void)
@@ -581,6 +648,7 @@ static void __exit opticon_exit(void)
 
 module_init(opticon_init);
 module_exit(opticon_exit);
+MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");
 
 module_param(debug, bool, S_IRUGO | S_IWUSR);