USB: serial: pl2303: add support for PL2303HXN

Prolific has developed a new USB to UART chip: PL2303HXN
PL2303HXN : PL2303GC/PL2303GS/PL2303GT/PL2303GL/PL2303GE/PL2303GB
The Vendor request used by the PL2303HXN (TYPE_HXN) is different from
the existing PL2303 series (TYPE_HX & TYPE_01).
Therefore, different Vendor requests are used to issue related commands.

1. Added a new TYPE_HXN type in pl2303_type_data, and then executes
   new Vendor request,new flow control and other related instructions
   if TYPE_HXN is recognized.

2. Because the new PL2303HXN only accept the new Vendor request,
   the old Vendor request cannot be accepted (the error message
   will be returned)
   So first determine the TYPE_HX or TYPE_HXN through
   PL2303_READ_TYPE_HX_STATUS in pl2303_startup.

  2.1 If the return message is "1", then the PL2303 is the existing
      TYPE_HX/ TYPE_01 series.
      The other settings in pl2303_startup are to continue execution.
  2.2 If the return message is "not 1", then the PL2303 is the new
      TYPE_HXN series.
      The other settings in pl2303_startup are ignored.
      (PL2303HXN will directly use the default value in the hardware,
       no need to add additional settings through the software)

3. In pl2303_open: Because TYPE_HXN is different from the instruction of reset
   down/up stream used by TYPE_HX.
   Therefore, we will also execute different instructions here.

4. In pl2303_set_termios: The UART flow control instructions used by
   TYPE_HXN/TYPE_HX/TYPE_01 are different.
   Therefore, we will also execute different instructions here.

5. In pl2303_vendor_read & pl2303_vendor_write, since TYPE_HXN is different
   from the vendor request instruction used by TYPE_HX/TYPE_01,
   it will also execute different instructions here.

6. In pl2303_update_reg: TYPE_HXN used different register for flow control.
   Therefore, we will also execute different instructions here.

Signed-off-by: Charles Yeh <charlesyeh522@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>

drivers/usb/serial/pl2303.c

@@ -47,6 +47,12 @@ static const struct usb_device_id id_table[] = {
 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_MOTOROLA) },
 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_ZTEK) },
 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_TB) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GC) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GB) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GT) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GL) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GE) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GS) },
 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID) },
 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID_RSAQ5) },
 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID),
@@ -130,9 +136,11 @@ MODULE_DEVICE_TABLE(usb, id_table);
 
 #define VENDOR_WRITE_REQUEST_TYPE	0x40
 #define VENDOR_WRITE_REQUEST		0x01
+#define VENDOR_WRITE_NREQUEST		0x80
 
 #define VENDOR_READ_REQUEST_TYPE	0xc0
 #define VENDOR_READ_REQUEST		0x01
+#define VENDOR_READ_NREQUEST		0x81
 
 #define UART_STATE_INDEX		8
 #define UART_STATE_MSR_MASK		0x8b
@@ -148,11 +156,24 @@ MODULE_DEVICE_TABLE(usb, id_table);
 
 #define PL2303_FLOWCTRL_MASK		0xf0
 
+#define PL2303_READ_TYPE_HX_STATUS	0x8080
+
+#define PL2303_HXN_RESET_REG		0x07
+#define PL2303_HXN_RESET_UPSTREAM_PIPE	0x02
+#define PL2303_HXN_RESET_DOWNSTREAM_PIPE	0x01
+
+#define PL2303_HXN_FLOWCTRL_REG		0x0a
+#define PL2303_HXN_FLOWCTRL_MASK	0x1c
+#define PL2303_HXN_FLOWCTRL_NONE	0x1c
+#define PL2303_HXN_FLOWCTRL_RTS_CTS	0x18
+#define PL2303_HXN_FLOWCTRL_XON_XOFF	0x0c
+
 static void pl2303_set_break(struct usb_serial_port *port, bool enable);
 
 enum pl2303_type {
 	TYPE_01,	/* Type 0 and 1 (difference unknown) */
 	TYPE_HX,	/* HX version of the pl2303 chip */
+	TYPE_HXN,	/* HXN version of the pl2303 chip */
 	TYPE_COUNT
 };
 
@@ -184,16 +205,26 @@ static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
 	[TYPE_HX] = {
 		.max_baud_rate		= 12000000,
 	},
+	[TYPE_HXN] = {
+		.max_baud_rate		= 12000000,
+	},
 };
 
 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
 							unsigned char buf[1])
 {
+	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
 	struct device *dev = &serial->interface->dev;
+	u8 request;
 	int res;
 
+	if (spriv->type == &pl2303_type_data[TYPE_HXN])
+		request = VENDOR_READ_NREQUEST;
+	else
+		request = VENDOR_READ_REQUEST;
+
 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
-			VENDOR_READ_REQUEST, VENDOR_READ_REQUEST_TYPE,
+			request, VENDOR_READ_REQUEST_TYPE,
 			value, 0, buf, 1, 100);
 	if (res != 1) {
 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
@@ -211,13 +242,20 @@ static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
 
 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
 {
+	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
 	struct device *dev = &serial->interface->dev;
+	u8 request;
 	int res;
 
 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
 
+	if (spriv->type == &pl2303_type_data[TYPE_HXN])
+		request = VENDOR_WRITE_NREQUEST;
+	else
+		request = VENDOR_WRITE_REQUEST;
+
 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
-			VENDOR_WRITE_REQUEST, VENDOR_WRITE_REQUEST_TYPE,
+			request, VENDOR_WRITE_REQUEST_TYPE,
 			value, index, NULL, 0, 100);
 	if (res) {
 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
@@ -230,6 +268,7 @@ static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
 
 static int pl2303_update_reg(struct usb_serial *serial, u8 reg, u8 mask, u8 val)
 {
+	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
 	int ret = 0;
 	u8 *buf;
 
@@ -237,7 +276,11 @@ static int pl2303_update_reg(struct usb_serial *serial, u8 reg, u8 mask, u8 val)
 	if (!buf)
 		return -ENOMEM;
 
-	ret = pl2303_vendor_read(serial, reg | 0x80, buf);
+	if (spriv->type == &pl2303_type_data[TYPE_HXN])
+		ret = pl2303_vendor_read(serial, reg, buf);
+	else
+		ret = pl2303_vendor_read(serial, reg | 0x80, buf);
+
 	if (ret)
 		goto out_free;
 
@@ -320,6 +363,7 @@ static int pl2303_startup(struct usb_serial *serial)
 	struct pl2303_serial_private *spriv;
 	enum pl2303_type type = TYPE_01;
 	unsigned char *buf;
+	int res;
 
 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
 	if (!spriv)
@@ -341,26 +385,37 @@ static int pl2303_startup(struct usb_serial *serial)
 		type = TYPE_01;		/* type 1 */
 	dev_dbg(&serial->interface->dev, "device type: %d\n", type);
 
+	if (type == TYPE_HX) {
+		res = usb_control_msg(serial->dev,
+				usb_rcvctrlpipe(serial->dev, 0),
+				VENDOR_READ_REQUEST, VENDOR_READ_REQUEST_TYPE,
+				PL2303_READ_TYPE_HX_STATUS, 0, buf, 1, 100);
+		if (res != 1)
+			type = TYPE_HXN;
+	}
+
 	spriv->type = &pl2303_type_data[type];
 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
 	spriv->quirks |= spriv->type->quirks;
 
 	usb_set_serial_data(serial, spriv);
 
-	pl2303_vendor_read(serial, 0x8484, buf);
+	if (type != TYPE_HXN) {
-	pl2303_vendor_write(serial, 0x0404, 0);
+		pl2303_vendor_read(serial, 0x8484, buf);
-	pl2303_vendor_read(serial, 0x8484, buf);
+		pl2303_vendor_write(serial, 0x0404, 0);
-	pl2303_vendor_read(serial, 0x8383, buf);
+		pl2303_vendor_read(serial, 0x8484, buf);
-	pl2303_vendor_read(serial, 0x8484, buf);
+		pl2303_vendor_read(serial, 0x8383, buf);
-	pl2303_vendor_write(serial, 0x0404, 1);
+		pl2303_vendor_read(serial, 0x8484, buf);
-	pl2303_vendor_read(serial, 0x8484, buf);
+		pl2303_vendor_write(serial, 0x0404, 1);
-	pl2303_vendor_read(serial, 0x8383, buf);
+		pl2303_vendor_read(serial, 0x8484, buf);
-	pl2303_vendor_write(serial, 0, 1);
+		pl2303_vendor_read(serial, 0x8383, buf);
-	pl2303_vendor_write(serial, 1, 0);
+		pl2303_vendor_write(serial, 0, 1);
-	if (spriv->quirks & PL2303_QUIRK_LEGACY)
+		pl2303_vendor_write(serial, 1, 0);
-		pl2303_vendor_write(serial, 2, 0x24);
+		if (spriv->quirks & PL2303_QUIRK_LEGACY)
-	else
+			pl2303_vendor_write(serial, 2, 0x24);
-		pl2303_vendor_write(serial, 2, 0x44);
+		else
+			pl2303_vendor_write(serial, 2, 0x44);
+	}
 
 	kfree(buf);
 
@@ -719,14 +774,31 @@ static void pl2303_set_termios(struct tty_struct *tty,
 	}
 
 	if (C_CRTSCTS(tty)) {
-		if (spriv->quirks & PL2303_QUIRK_LEGACY)
+		if (spriv->quirks & PL2303_QUIRK_LEGACY) {
 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x40);
-		else
+		} else if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
+			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
+					PL2303_HXN_FLOWCTRL_MASK,
+					PL2303_HXN_FLOWCTRL_RTS_CTS);
+		} else {
 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x60);
+		}
 	} else if (pl2303_enable_xonxoff(tty, spriv->type)) {
-		pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0xc0);
+		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
+			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
+					PL2303_HXN_FLOWCTRL_MASK,
+					PL2303_HXN_FLOWCTRL_XON_XOFF);
+		} else {
+			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0xc0);
+		}
 	} else {
-		pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0);
+		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
+			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
+					PL2303_HXN_FLOWCTRL_MASK,
+					PL2303_HXN_FLOWCTRL_NONE);
+		} else {
+			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0);
+		}
 	}
 
 	kfree(buf);
@@ -767,8 +839,14 @@ static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
 		usb_clear_halt(serial->dev, port->read_urb->pipe);
 	} else {
 		/* reset upstream data pipes */
-		pl2303_vendor_write(serial, 8, 0);
+		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
-		pl2303_vendor_write(serial, 9, 0);
+			pl2303_vendor_write(serial, PL2303_HXN_RESET_REG,
+					PL2303_HXN_RESET_UPSTREAM_PIPE |
+					PL2303_HXN_RESET_DOWNSTREAM_PIPE);
+		} else {
+			pl2303_vendor_write(serial, 8, 0);
+			pl2303_vendor_write(serial, 9, 0);
+		}
 	}
 
 	/* Setup termios */

drivers/usb/serial/pl2303.h

@@ -9,6 +9,12 @@
 #define PL2303_VENDOR_ID	0x067b
 #define PL2303_PRODUCT_ID	0x2303
 #define PL2303_PRODUCT_ID_TB		0x2304
+#define PL2303_PRODUCT_ID_GC		0x23a3
+#define PL2303_PRODUCT_ID_GB		0x23b3
+#define PL2303_PRODUCT_ID_GT		0x23c3
+#define PL2303_PRODUCT_ID_GL		0x23d3
+#define PL2303_PRODUCT_ID_GE		0x23e3
+#define PL2303_PRODUCT_ID_GS		0x23f3
 #define PL2303_PRODUCT_ID_RSAQ2		0x04bb
 #define PL2303_PRODUCT_ID_DCU11		0x1234
 #define PL2303_PRODUCT_ID_PHAROS	0xaaa0