USB: f81232: implement read IIR/MSR with endpoint

The interrupt endpoint will report current IIR. If we got IIR with MSR changed
, We will do read MSR with interrupt_work worker to do f81232_read_msr()
function.

Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index 12840cdc8532e7462973db462d7acb170a1adf2f..e53ceea7ec355ffeb083a5413a03d8fbe43ba0c0 100644 (file)
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -31,6 +31,13 @@ static const struct usb_device_id id_table[] = {
 };
 MODULE_DEVICE_TABLE(usb, id_table);
 
+/* USB Control EP parameter */
+#define F81232_REGISTER_REQUEST        0xa0
+#define F81232_GET_REGISTER            0xc0
+
+#define SERIAL_BASE_ADDRESS                    0x0120
+#define MODEM_STATUS_REGISTER          (0x06 + SERIAL_BASE_ADDRESS)
+
 #define CONTROL_DTR                    0x01
 #define CONTROL_RTS                    0x02
 
@@ -49,19 +56,112 @@ struct f81232_private {
        struct mutex lock;
        u8 line_control;
        u8 modem_status;
+       struct work_struct interrupt_work;
+       struct usb_serial_port *port;
 };
 
+static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
+{
+       int status;
+       u8 *tmp;
+       struct usb_device *dev = port->serial->dev;
+
+       tmp = kmalloc(sizeof(*val), GFP_KERNEL);
+       if (!tmp)
+               return -ENOMEM;
+
+       status = usb_control_msg(dev,
+                               usb_rcvctrlpipe(dev, 0),
+                               F81232_REGISTER_REQUEST,
+                               F81232_GET_REGISTER,
+                               reg,
+                               0,
+                               tmp,
+                               sizeof(*val),
+                               USB_CTRL_GET_TIMEOUT);
+       if (status != sizeof(*val)) {
+               dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
+
+               if (status < 0)
+                       status = usb_translate_errors(status);
+               else
+                       status = -EIO;
+       } else {
+               status = 0;
+               *val = *tmp;
+       }
+
+       kfree(tmp);
+       return status;
+}
+
+static void f81232_read_msr(struct usb_serial_port *port)
+{
+       int status;
+       u8 current_msr;
+       struct tty_struct *tty;
+       struct f81232_private *priv = usb_get_serial_port_data(port);
+
+       mutex_lock(&priv->lock);
+       status = f81232_get_register(port, MODEM_STATUS_REGISTER,
+                       &current_msr);
+       if (status) {
+               dev_err(&port->dev, "%s fail, status: %d\n", __func__, status);
+               mutex_unlock(&priv->lock);
+               return;
+       }
+
+       if (!(current_msr & UART_MSR_ANY_DELTA)) {
+               mutex_unlock(&priv->lock);
+               return;
+       }
+
+       priv->modem_status = current_msr;
+
+       if (current_msr & UART_MSR_DCTS)
+               port->icount.cts++;
+       if (current_msr & UART_MSR_DDSR)
+               port->icount.dsr++;
+       if (current_msr & UART_MSR_TERI)
+               port->icount.rng++;
+       if (current_msr & UART_MSR_DDCD) {
+               port->icount.dcd++;
+               tty = tty_port_tty_get(&port->port);
+               if (tty) {
+                       usb_serial_handle_dcd_change(port, tty,
+                                       current_msr & UART_MSR_DCD);
+
+                       tty_kref_put(tty);
+               }
+       }
+
+       wake_up_interruptible(&port->port.delta_msr_wait);
+       mutex_unlock(&priv->lock);
+}
+
 static void f81232_update_line_status(struct usb_serial_port *port,
                                      unsigned char *data,
-                                     unsigned int actual_length)
+                                     size_t actual_length)
 {
-       /*
-        * FIXME: Update port->icount, and call
-        *
-        *              wake_up_interruptible(&port->port.delta_msr_wait);
-        *
-        *        on MSR changes.
-        */
+       struct f81232_private *priv = usb_get_serial_port_data(port);
+
+       if (!actual_length)
+               return;
+
+       switch (data[0] & 0x07) {
+       case 0x00: /* msr change */
+               dev_dbg(&port->dev, "IIR: MSR Change: %02x\n", data[0]);
+               schedule_work(&priv->interrupt_work);
+               break;
+       case 0x02: /* tx-empty */
+               break;
+       case 0x04: /* rx data available */
+               break;
+       case 0x06: /* lsr change */
+               /* we can forget it. the LSR will read from bulk-in */
+               dev_dbg(&port->dev, "IIR: LSR Change: %02x\n", data[0]);
+               break;
+       }
 }
 
 static void f81232_read_int_callback(struct urb *urb)
@@ -276,6 +376,14 @@ static int f81232_ioctl(struct tty_struct *tty,
        return -ENOIOCTLCMD;
 }
 
+static void  f81232_interrupt_work(struct work_struct *work)
+{
+       struct f81232_private *priv =
+               container_of(work, struct f81232_private, interrupt_work);
+
+       f81232_read_msr(priv->port);
+}
+
 static int f81232_port_probe(struct usb_serial_port *port)
 {
        struct f81232_private *priv;
@@ -285,10 +393,12 @@ static int f81232_port_probe(struct usb_serial_port *port)
                return -ENOMEM;
 
        mutex_init(&priv->lock);
+       INIT_WORK(&priv->interrupt_work,  f81232_interrupt_work);
 
        usb_set_serial_port_data(port, priv);
 
        port->port.drain_delay = 256;
+       priv->port = port;
 
        return 0;
 }