[PATCH V8 04/10] USB: f81232: implement read IIR/MSR with endpoint

From: Peter Hung
Date: Thu Feb 26 2015 - 05:02:41 EST


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@xxxxxxxxx>
---
drivers/usb/serial/f81232.c | 126 +++++++++++++++++++++++++++++++++++++++++---
1 file changed, 118 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index cf5b902..46a81ef 100644
--- 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(u8),
+ USB_CTRL_GET_TIMEOUT);
+ if (status != sizeof(*val)) {
+ dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
+
+ if (status == 0)
+ status = -EIO;
+ else
+ status = usb_translate_errors(status);
+ } 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)
@@ -272,6 +372,14 @@ 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;
@@ -281,10 +389,12 @@ 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;
}
--
1.9.1

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