[PATCH V7 02/11] USB: f81232: add preparatory functions

[Peter Hung <hpeter@gmail.com>]

We add f81232_get_register()/f81232_set_register() and necessary defines
for future patch with communication with F81232 USB control endpoint.

Because of this is a preparatory patch, there are unused function warning
with compiling. The functions will used with following patches.

Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
---
 drivers/usb/serial/f81232.c | 79 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index 669a2f2..1f29b95 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -30,6 +30,11 @@ 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 F81232_SET_REGISTER	0x40
+
 #define CONTROL_DTR			0x01
 #define CONTROL_RTS			0x02
 
@@ -50,6 +55,80 @@ struct f81232_private {
 	u8 modem_status;
 };
 
+static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *data)
+{
+	int status;
+	u8 *tmp;
+	struct usb_device *dev = port->serial->dev;
+
+	if (!data)
+		return -EFAULT;
+
+	tmp = kmalloc(sizeof(u8), 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 <= 0) {
+		/* show something with failed */
+		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; /* on success */
+		memcpy((void*) data, (void*) tmp, sizeof(u8));
+	}
+
+	kfree(tmp);
+	return status;
+}
+
+static int f81232_set_register(struct usb_serial_port *port, u16 reg, u8 data)
+{
+	int status;
+	u8 *tmp;
+	struct usb_device *dev = port->serial->dev;
+
+	tmp = kmalloc(sizeof(u8), GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
+
+	memcpy((void*) tmp, (void*) &data, sizeof(u8));
+
+	status = usb_control_msg(dev,
+				usb_sndctrlpipe(dev, 0),
+				F81232_REGISTER_REQUEST,
+				F81232_SET_REGISTER,
+				reg,
+				0,
+				tmp,
+				sizeof(u8),
+				USB_CTRL_SET_TIMEOUT);
+	if (status <= 0) {
+		/* show something with failed */
+		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; /* on success */
+
+	kfree(tmp);
+	return status;
+}
 static void f81232_update_line_status(struct usb_serial_port *port,
 				      unsigned char *data,
 				      unsigned int actual_length)
-- 
1.9.1