Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1165 insertions, 0 deletions

diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
new file mode 100644
index 000000000..16118d9f2
--- /dev/null
+++ b/drivers/usb/serial/pl2303.c
@@ -0,0 +1,1165 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Prolific PL2303 USB to serial adaptor driver
+ *
+ * Copyright (C) 2001-2007 Greg Kroah-Hartman (greg@kroah.com)
+ * Copyright (C) 2003 IBM Corp.
+ *
+ * Original driver for 2.2.x by anonymous
+ *
+ * See Documentation/usb/usb-serial.rst for more information on using this
+ * driver
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <asm/unaligned.h>
+#include "pl2303.h"
+
+
+#define PL2303_QUIRK_UART_STATE_IDX0		BIT(0)
+#define PL2303_QUIRK_LEGACY			BIT(1)
+#define PL2303_QUIRK_ENDPOINT_HACK		BIT(2)
+
+static const struct usb_device_id id_table[] = {
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID),
+		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ2) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_DCU11) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ3) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_CHILITAG) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_PHAROS) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_ALDIGA) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_MMX) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GPRS) },
+	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_HCR331) },
+	{ 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),
+		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
+	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC485),
+		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
+	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC232B),
+		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
+	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID2) },
+	{ USB_DEVICE(ATEN_VENDOR_ID2, ATEN_PRODUCT_ID) },
+	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID) },
+	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID_UCSGT) },
+	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID) },
+	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID_2080) },
+	{ USB_DEVICE(MA620_VENDOR_ID, MA620_PRODUCT_ID) },
+	{ USB_DEVICE(RATOC_VENDOR_ID, RATOC_PRODUCT_ID) },
+	{ USB_DEVICE(TRIPP_VENDOR_ID, TRIPP_PRODUCT_ID) },
+	{ USB_DEVICE(RADIOSHACK_VENDOR_ID, RADIOSHACK_PRODUCT_ID) },
+	{ USB_DEVICE(DCU10_VENDOR_ID, DCU10_PRODUCT_ID) },
+	{ USB_DEVICE(SITECOM_VENDOR_ID, SITECOM_PRODUCT_ID) },
+	{ USB_DEVICE(ALCATEL_VENDOR_ID, ALCATEL_PRODUCT_ID) },
+	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_SX1),
+		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
+	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X65),
+		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
+	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X75),
+		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
+	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_EF81),
+		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
+	{ USB_DEVICE(BENQ_VENDOR_ID, BENQ_PRODUCT_ID_S81) }, /* Benq/Siemens S81 */
+	{ USB_DEVICE(SYNTECH_VENDOR_ID, SYNTECH_PRODUCT_ID) },
+	{ USB_DEVICE(NOKIA_CA42_VENDOR_ID, NOKIA_CA42_PRODUCT_ID) },
+	{ USB_DEVICE(CA_42_CA42_VENDOR_ID, CA_42_CA42_PRODUCT_ID) },
+	{ USB_DEVICE(SAGEM_VENDOR_ID, SAGEM_PRODUCT_ID) },
+	{ USB_DEVICE(LEADTEK_VENDOR_ID, LEADTEK_9531_PRODUCT_ID) },
+	{ USB_DEVICE(SPEEDDRAGON_VENDOR_ID, SPEEDDRAGON_PRODUCT_ID) },
+	{ USB_DEVICE(DATAPILOT_U2_VENDOR_ID, DATAPILOT_U2_PRODUCT_ID) },
+	{ USB_DEVICE(BELKIN_VENDOR_ID, BELKIN_PRODUCT_ID) },
+	{ USB_DEVICE(ALCOR_VENDOR_ID, ALCOR_PRODUCT_ID),
+		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
+	{ USB_DEVICE(WS002IN_VENDOR_ID, WS002IN_PRODUCT_ID) },
+	{ USB_DEVICE(COREGA_VENDOR_ID, COREGA_PRODUCT_ID) },
+	{ USB_DEVICE(YCCABLE_VENDOR_ID, YCCABLE_PRODUCT_ID) },
+	{ USB_DEVICE(SUPERIAL_VENDOR_ID, SUPERIAL_PRODUCT_ID) },
+	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220_PRODUCT_ID) },
+	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220TA_PRODUCT_ID) },
+	{ USB_DEVICE(HP_VENDOR_ID, HP_LD381_PRODUCT_ID) },
+	{ USB_DEVICE(HP_VENDOR_ID, HP_LD381GC_PRODUCT_ID) },
+	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960_PRODUCT_ID) },
+	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960TA_PRODUCT_ID) },
+	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM220_PRODUCT_ID) },
+	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM960_PRODUCT_ID) },
+	{ USB_DEVICE(HP_VENDOR_ID, HP_LM920_PRODUCT_ID) },
+	{ USB_DEVICE(HP_VENDOR_ID, HP_LM930_PRODUCT_ID) },
+	{ USB_DEVICE(HP_VENDOR_ID, HP_LM940_PRODUCT_ID) },
+	{ USB_DEVICE(HP_VENDOR_ID, HP_TD620_PRODUCT_ID) },
+	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
+	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
+	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
+	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
+	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
+	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530GC_PRODUCT_ID) },
+	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
+	{ USB_DEVICE(AT_VENDOR_ID, AT_VTKIT3_PRODUCT_ID) },
+	{ USB_DEVICE(IBM_VENDOR_ID, IBM_PRODUCT_ID) },
+	{ }					/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, id_table);
+
+#define SET_LINE_REQUEST_TYPE		0x21
+#define SET_LINE_REQUEST		0x20
+
+#define SET_CONTROL_REQUEST_TYPE	0x21
+#define SET_CONTROL_REQUEST		0x22
+#define CONTROL_DTR			0x01
+#define CONTROL_RTS			0x02
+
+#define BREAK_REQUEST_TYPE		0x21
+#define BREAK_REQUEST			0x23
+#define BREAK_ON			0xffff
+#define BREAK_OFF			0x0000
+
+#define GET_LINE_REQUEST_TYPE		0xa1
+#define GET_LINE_REQUEST		0x21
+
+#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
+#define UART_STATE_TRANSIENT_MASK	0x74
+#define UART_DCD			0x01
+#define UART_DSR			0x02
+#define UART_BREAK_ERROR		0x04
+#define UART_RING			0x08
+#define UART_FRAME_ERROR		0x10
+#define UART_PARITY_ERROR		0x20
+#define UART_OVERRUN_ERROR		0x40
+#define UART_CTS			0x80
+
+#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
+};
+
+struct pl2303_type_data {
+	speed_t max_baud_rate;
+	unsigned long quirks;
+	unsigned int no_autoxonxoff:1;
+	unsigned int no_divisors:1;
+};
+
+struct pl2303_serial_private {
+	const struct pl2303_type_data *type;
+	unsigned long quirks;
+};
+
+struct pl2303_private {
+	spinlock_t lock;
+	u8 line_control;
+	u8 line_status;
+
+	u8 line_settings[7];
+};
+
+static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
+	[TYPE_01] = {
+		.max_baud_rate		= 1228800,
+		.quirks			= PL2303_QUIRK_LEGACY,
+		.no_autoxonxoff		= true,
+	},
+	[TYPE_HX] = {
+		.max_baud_rate		= 12000000,
+	},
+	[TYPE_HXN] = {
+		.max_baud_rate		= 12000000,
+		.no_divisors		= true,
+	},
+};
+
+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),
+			request, VENDOR_READ_REQUEST_TYPE,
+			value, 0, buf, 1, 100);
+	if (res != 1) {
+		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
+								value, res);
+		if (res >= 0)
+			res = -EIO;
+
+		return res;
+	}
+
+	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
+
+	return 0;
+}
+
+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),
+			request, VENDOR_WRITE_REQUEST_TYPE,
+			value, index, NULL, 0, 100);
+	if (res) {
+		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
+								value, res);
+		return res;
+	}
+
+	return 0;
+}
+
+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;
+
+	buf = kmalloc(1, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	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;
+
+	*buf &= ~mask;
+	*buf |= val & mask;
+
+	ret = pl2303_vendor_write(serial, reg, *buf);
+out_free:
+	kfree(buf);
+
+	return ret;
+}
+
+static int pl2303_probe(struct usb_serial *serial,
+					const struct usb_device_id *id)
+{
+	usb_set_serial_data(serial, (void *)id->driver_info);
+
+	return 0;
+}
+
+/*
+ * Use interrupt endpoint from first interface if available.
+ *
+ * This is needed due to the looney way its endpoints are set up.
+ */
+static int pl2303_endpoint_hack(struct usb_serial *serial,
+					struct usb_serial_endpoints *epds)
+{
+	struct usb_interface *interface = serial->interface;
+	struct usb_device *dev = serial->dev;
+	struct device *ddev = &interface->dev;
+	struct usb_host_interface *iface_desc;
+	struct usb_endpoint_descriptor *endpoint;
+	unsigned int i;
+
+	if (interface == dev->actconfig->interface[0])
+		return 0;
+
+	/* check out the endpoints of the other interface */
+	iface_desc = dev->actconfig->interface[0]->cur_altsetting;
+
+	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+		endpoint = &iface_desc->endpoint[i].desc;
+
+		if (!usb_endpoint_is_int_in(endpoint))
+			continue;
+
+		dev_dbg(ddev, "found interrupt in on separate interface\n");
+		if (epds->num_interrupt_in < ARRAY_SIZE(epds->interrupt_in))
+			epds->interrupt_in[epds->num_interrupt_in++] = endpoint;
+	}
+
+	return 0;
+}
+
+static int pl2303_calc_num_ports(struct usb_serial *serial,
+					struct usb_serial_endpoints *epds)
+{
+	unsigned long quirks = (unsigned long)usb_get_serial_data(serial);
+	struct device *dev = &serial->interface->dev;
+	int ret;
+
+	if (quirks & PL2303_QUIRK_ENDPOINT_HACK) {
+		ret = pl2303_endpoint_hack(serial, epds);
+		if (ret)
+			return ret;
+	}
+
+	if (epds->num_interrupt_in < 1) {
+		dev_err(dev, "required interrupt-in endpoint missing\n");
+		return -ENODEV;
+	}
+
+	return 1;
+}
+
+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)
+		return -ENOMEM;
+
+	buf = kmalloc(1, GFP_KERNEL);
+	if (!buf) {
+		kfree(spriv);
+		return -ENOMEM;
+	}
+
+	if (serial->dev->descriptor.bDeviceClass == 0x02)
+		type = TYPE_01;		/* type 0 */
+	else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
+		type = TYPE_HX;
+	else if (serial->dev->descriptor.bDeviceClass == 0x00)
+		type = TYPE_01;		/* type 1 */
+	else if (serial->dev->descriptor.bDeviceClass == 0xFF)
+		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);
+
+	if (type != TYPE_HXN) {
+		pl2303_vendor_read(serial, 0x8484, buf);
+		pl2303_vendor_write(serial, 0x0404, 0);
+		pl2303_vendor_read(serial, 0x8484, buf);
+		pl2303_vendor_read(serial, 0x8383, buf);
+		pl2303_vendor_read(serial, 0x8484, buf);
+		pl2303_vendor_write(serial, 0x0404, 1);
+		pl2303_vendor_read(serial, 0x8484, buf);
+		pl2303_vendor_read(serial, 0x8383, buf);
+		pl2303_vendor_write(serial, 0, 1);
+		pl2303_vendor_write(serial, 1, 0);
+		if (spriv->quirks & PL2303_QUIRK_LEGACY)
+			pl2303_vendor_write(serial, 2, 0x24);
+		else
+			pl2303_vendor_write(serial, 2, 0x44);
+	}
+
+	kfree(buf);
+
+	return 0;
+}
+
+static void pl2303_release(struct usb_serial *serial)
+{
+	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+
+	kfree(spriv);
+}
+
+static int pl2303_port_probe(struct usb_serial_port *port)
+{
+	struct pl2303_private *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	spin_lock_init(&priv->lock);
+
+	usb_set_serial_port_data(port, priv);
+
+	port->port.drain_delay = 256;
+
+	return 0;
+}
+
+static int pl2303_port_remove(struct usb_serial_port *port)
+{
+	struct pl2303_private *priv = usb_get_serial_port_data(port);
+
+	kfree(priv);
+
+	return 0;
+}
+
+static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
+{
+	struct usb_device *dev = port->serial->dev;
+	int retval;
+
+	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
+
+	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
+				 value, 0, NULL, 0, 100);
+	if (retval)
+		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
+
+	return retval;
+}
+
+/*
+ * Returns the nearest supported baud rate that can be set directly without
+ * using divisors.
+ */
+static speed_t pl2303_get_supported_baud_rate(speed_t baud)
+{
+	static const speed_t baud_sup[] = {
+		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
+		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
+		614400, 921600, 1228800, 2457600, 3000000, 6000000
+	};
+
+	unsigned i;
+
+	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
+		if (baud_sup[i] > baud)
+			break;
+	}
+
+	if (i == ARRAY_SIZE(baud_sup))
+		baud = baud_sup[i - 1];
+	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
+		baud = baud_sup[i - 1];
+	else
+		baud = baud_sup[i];
+
+	return baud;
+}
+
+/*
+ * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
+ *       use 9600 baud.
+ */
+static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
+								speed_t baud)
+{
+	put_unaligned_le32(baud, buf);
+
+	return baud;
+}
+
+static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
+								speed_t baud)
+{
+	unsigned int baseline, mantissa, exponent;
+
+	/*
+	 * Apparently the formula is:
+	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
+	 * where
+	 *   mantissa = buf[8:0]
+	 *   exponent = buf[11:9]
+	 */
+	baseline = 12000000 * 32;
+	mantissa = baseline / baud;
+	if (mantissa == 0)
+		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
+	exponent = 0;
+	while (mantissa >= 512) {
+		if (exponent < 7) {
+			mantissa >>= 2;	/* divide by 4 */
+			exponent++;
+		} else {
+			/* Exponent is maxed. Trim mantissa and leave. */
+			mantissa = 511;
+			break;
+		}
+	}
+
+	buf[3] = 0x80;
+	buf[2] = 0;
+	buf[1] = exponent << 1 | mantissa >> 8;
+	buf[0] = mantissa & 0xff;
+
+	/* Calculate and return the exact baud rate. */
+	baud = (baseline / mantissa) >> (exponent << 1);
+
+	return baud;
+}
+
+static void pl2303_encode_baud_rate(struct tty_struct *tty,
+					struct usb_serial_port *port,
+					u8 buf[4])
+{
+	struct usb_serial *serial = port->serial;
+	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+	speed_t	baud_sup;
+	speed_t baud;
+
+	baud = tty_get_baud_rate(tty);
+	dev_dbg(&port->dev, "baud requested = %u\n", baud);
+	if (!baud)
+		return;
+
+	if (spriv->type->max_baud_rate)
+		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
+	/*
+	 * Use direct method for supported baud rates, otherwise use divisors.
+	 * Newer chip types do not support divisor encoding.
+	 */
+	if (spriv->type->no_divisors)
+		baud_sup = baud;
+	else
+		baud_sup = pl2303_get_supported_baud_rate(baud);
+
+	if (baud == baud_sup)
+		baud = pl2303_encode_baud_rate_direct(buf, baud);
+	else
+		baud = pl2303_encode_baud_rate_divisor(buf, baud);
+
+	/* Save resulting baud rate */
+	tty_encode_baud_rate(tty, baud, baud);
+	dev_dbg(&port->dev, "baud set = %u\n", baud);
+}
+
+static int pl2303_get_line_request(struct usb_serial_port *port,
+							unsigned char buf[7])
+{
+	struct usb_device *udev = port->serial->dev;
+	int ret;
+
+	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
+				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
+				0, 0, buf, 7, 100);
+	if (ret != 7) {
+		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
+
+		if (ret >= 0)
+			ret = -EIO;
+
+		return ret;
+	}
+
+	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
+
+	return 0;
+}
+
+static int pl2303_set_line_request(struct usb_serial_port *port,
+							unsigned char buf[7])
+{
+	struct usb_device *udev = port->serial->dev;
+	int ret;
+
+	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
+				0, 0, buf, 7, 100);
+	if (ret < 0) {
+		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
+		return ret;
+	}
+
+	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
+
+	return 0;
+}
+
+static bool pl2303_termios_change(const struct ktermios *a, const struct ktermios *b)
+{
+	bool ixon_change;
+
+	ixon_change = ((a->c_iflag ^ b->c_iflag) & (IXON | IXANY)) ||
+			a->c_cc[VSTART] != b->c_cc[VSTART] ||
+			a->c_cc[VSTOP] != b->c_cc[VSTOP];
+
+	return tty_termios_hw_change(a, b) || ixon_change;
+}
+
+static bool pl2303_enable_xonxoff(struct tty_struct *tty, const struct pl2303_type_data *type)
+{
+	if (!I_IXON(tty) || I_IXANY(tty))
+		return false;
+
+	if (START_CHAR(tty) != 0x11 || STOP_CHAR(tty) != 0x13)
+		return false;
+
+	if (type->no_autoxonxoff)
+		return false;
+
+	return true;
+}
+
+static void pl2303_set_termios(struct tty_struct *tty,
+		struct usb_serial_port *port, struct ktermios *old_termios)
+{
+	struct usb_serial *serial = port->serial;
+	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+	struct pl2303_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	unsigned char *buf;
+	int ret;
+	u8 control;
+
+	if (old_termios && !pl2303_termios_change(&tty->termios, old_termios))
+		return;
+
+	buf = kzalloc(7, GFP_KERNEL);
+	if (!buf) {
+		/* Report back no change occurred */
+		if (old_termios)
+			tty->termios = *old_termios;
+		return;
+	}
+
+	pl2303_get_line_request(port, buf);
+
+	switch (C_CSIZE(tty)) {
+	case CS5:
+		buf[6] = 5;
+		break;
+	case CS6:
+		buf[6] = 6;
+		break;
+	case CS7:
+		buf[6] = 7;
+		break;
+	default:
+	case CS8:
+		buf[6] = 8;
+	}
+	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
+
+	/* For reference buf[0]:buf[3] baud rate value */
+	pl2303_encode_baud_rate(tty, port, &buf[0]);
+
+	/* For reference buf[4]=0 is 1 stop bits */
+	/* For reference buf[4]=1 is 1.5 stop bits */
+	/* For reference buf[4]=2 is 2 stop bits */
+	if (C_CSTOPB(tty)) {
+		/*
+		 * NOTE: Comply with "real" UARTs / RS232:
+		 *       use 1.5 instead of 2 stop bits with 5 data bits
+		 */
+		if (C_CSIZE(tty) == CS5) {
+			buf[4] = 1;
+			dev_dbg(&port->dev, "stop bits = 1.5\n");
+		} else {
+			buf[4] = 2;
+			dev_dbg(&port->dev, "stop bits = 2\n");
+		}
+	} else {
+		buf[4] = 0;
+		dev_dbg(&port->dev, "stop bits = 1\n");
+	}
+
+	if (C_PARENB(tty)) {
+		/* For reference buf[5]=0 is none parity */
+		/* For reference buf[5]=1 is odd parity */
+		/* For reference buf[5]=2 is even parity */
+		/* For reference buf[5]=3 is mark parity */
+		/* For reference buf[5]=4 is space parity */
+		if (C_PARODD(tty)) {
+			if (C_CMSPAR(tty)) {
+				buf[5] = 3;
+				dev_dbg(&port->dev, "parity = mark\n");
+			} else {
+				buf[5] = 1;
+				dev_dbg(&port->dev, "parity = odd\n");
+			}
+		} else {
+			if (C_CMSPAR(tty)) {
+				buf[5] = 4;
+				dev_dbg(&port->dev, "parity = space\n");
+			} else {
+				buf[5] = 2;
+				dev_dbg(&port->dev, "parity = even\n");
+			}
+		}
+	} else {
+		buf[5] = 0;
+		dev_dbg(&port->dev, "parity = none\n");
+	}
+
+	/*
+	 * Some PL2303 are known to lose bytes if you change serial settings
+	 * even to the same values as before. Thus we actually need to filter
+	 * in this specific case.
+	 *
+	 * Note that the tty_termios_hw_change check above is not sufficient
+	 * as a previously requested baud rate may differ from the one
+	 * actually used (and stored in old_termios).
+	 *
+	 * NOTE: No additional locking needed for line_settings as it is
+	 *       only used in set_termios, which is serialised against itself.
+	 */
+	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
+		ret = pl2303_set_line_request(port, buf);
+		if (!ret)
+			memcpy(priv->line_settings, buf, 7);
+	}
+
+	/* change control lines if we are switching to or from B0 */
+	spin_lock_irqsave(&priv->lock, flags);
+	control = priv->line_control;
+	if (C_BAUD(tty) == B0)
+		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
+	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
+		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
+	if (control != priv->line_control) {
+		control = priv->line_control;
+		spin_unlock_irqrestore(&priv->lock, flags);
+		pl2303_set_control_lines(port, control);
+	} else {
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+
+	if (C_CRTSCTS(tty)) {
+		if (spriv->quirks & PL2303_QUIRK_LEGACY) {
+			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x40);
+		} 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)) {
+		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 {
+		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);
+}
+
+static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
+{
+	struct pl2303_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	u8 control;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (on)
+		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
+	else
+		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
+	control = priv->line_control;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	pl2303_set_control_lines(port, control);
+}
+
+static void pl2303_close(struct usb_serial_port *port)
+{
+	usb_serial_generic_close(port);
+	usb_kill_urb(port->interrupt_in_urb);
+	pl2303_set_break(port, false);
+}
+
+static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
+{
+	struct usb_serial *serial = port->serial;
+	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+	int result;
+
+	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
+		usb_clear_halt(serial->dev, port->write_urb->pipe);
+		usb_clear_halt(serial->dev, port->read_urb->pipe);
+	} else {
+		/* reset upstream data pipes */
+		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
+			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 */
+	if (tty)
+		pl2303_set_termios(tty, port, NULL);
+
+	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
+	if (result) {
+		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
+			result);
+		return result;
+	}
+
+	result = usb_serial_generic_open(tty, port);
+	if (result) {
+		usb_kill_urb(port->interrupt_in_urb);
+		return result;
+	}
+
+	return 0;
+}
+
+static int pl2303_tiocmset(struct tty_struct *tty,
+			   unsigned int set, unsigned int clear)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct pl2303_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	u8 control;
+	int ret;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (set & TIOCM_RTS)
+		priv->line_control |= CONTROL_RTS;
+	if (set & TIOCM_DTR)
+		priv->line_control |= CONTROL_DTR;
+	if (clear & TIOCM_RTS)
+		priv->line_control &= ~CONTROL_RTS;
+	if (clear & TIOCM_DTR)
+		priv->line_control &= ~CONTROL_DTR;
+	control = priv->line_control;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	ret = pl2303_set_control_lines(port, control);
+	if (ret)
+		return usb_translate_errors(ret);
+
+	return 0;
+}
+
+static int pl2303_tiocmget(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct pl2303_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	unsigned int mcr;
+	unsigned int status;
+	unsigned int result;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	mcr = priv->line_control;
+	status = priv->line_status;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
+		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
+		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
+		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
+		  | ((status & UART_RING)	? TIOCM_RI  : 0)
+		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
+
+	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
+
+	return result;
+}
+
+static int pl2303_carrier_raised(struct usb_serial_port *port)
+{
+	struct pl2303_private *priv = usb_get_serial_port_data(port);
+
+	if (priv->line_status & UART_DCD)
+		return 1;
+
+	return 0;
+}
+
+static int pl2303_get_serial(struct tty_struct *tty,
+			struct serial_struct *ss)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	ss->type = PORT_16654;
+	ss->line = port->minor;
+	ss->port = port->port_number;
+	ss->baud_base = 460800;
+	return 0;
+}
+
+static void pl2303_set_break(struct usb_serial_port *port, bool enable)
+{
+	struct usb_serial *serial = port->serial;
+	u16 state;
+	int result;
+
+	if (enable)
+		state = BREAK_ON;
+	else
+		state = BREAK_OFF;
+
+	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
+			state == BREAK_OFF ? "off" : "on");
+
+	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
+				 0, NULL, 0, 100);
+	if (result)
+		dev_err(&port->dev, "error sending break = %d\n", result);
+}
+
+static void pl2303_break_ctl(struct tty_struct *tty, int state)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	pl2303_set_break(port, state);
+}
+
+static void pl2303_update_line_status(struct usb_serial_port *port,
+				      unsigned char *data,
+				      unsigned int actual_length)
+{
+	struct usb_serial *serial = port->serial;
+	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+	struct pl2303_private *priv = usb_get_serial_port_data(port);
+	struct tty_struct *tty;
+	unsigned long flags;
+	unsigned int status_idx = UART_STATE_INDEX;
+	u8 status;
+	u8 delta;
+
+	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
+		status_idx = 0;
+
+	if (actual_length < status_idx + 1)
+		return;
+
+	status = data[status_idx];
+
+	/* Save off the uart status for others to look at */
+	spin_lock_irqsave(&priv->lock, flags);
+	delta = priv->line_status ^ status;
+	priv->line_status = status;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	if (status & UART_BREAK_ERROR)
+		usb_serial_handle_break(port);
+
+	if (delta & UART_STATE_MSR_MASK) {
+		if (delta & UART_CTS)
+			port->icount.cts++;
+		if (delta & UART_DSR)
+			port->icount.dsr++;
+		if (delta & UART_RING)
+			port->icount.rng++;
+		if (delta & UART_DCD) {
+			port->icount.dcd++;
+			tty = tty_port_tty_get(&port->port);
+			if (tty) {
+				usb_serial_handle_dcd_change(port, tty,
+							status & UART_DCD);
+				tty_kref_put(tty);
+			}
+		}
+
+		wake_up_interruptible(&port->port.delta_msr_wait);
+	}
+}
+
+static void pl2303_read_int_callback(struct urb *urb)
+{
+	struct usb_serial_port *port =  urb->context;
+	unsigned char *data = urb->transfer_buffer;
+	unsigned int actual_length = urb->actual_length;
+	int status = urb->status;
+	int retval;
+
+	switch (status) {
+	case 0:
+		/* success */
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		/* this urb is terminated, clean up */
+		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
+			__func__, status);
+		return;
+	default:
+		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
+			__func__, status);
+		goto exit;
+	}
+
+	usb_serial_debug_data(&port->dev, __func__,
+			      urb->actual_length, urb->transfer_buffer);
+
+	pl2303_update_line_status(port, data, actual_length);
+
+exit:
+	retval = usb_submit_urb(urb, GFP_ATOMIC);
+	if (retval) {
+		dev_err(&port->dev,
+			"%s - usb_submit_urb failed with result %d\n",
+			__func__, retval);
+	}
+}
+
+static void pl2303_process_read_urb(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+	struct pl2303_private *priv = usb_get_serial_port_data(port);
+	unsigned char *data = urb->transfer_buffer;
+	char tty_flag = TTY_NORMAL;
+	unsigned long flags;
+	u8 line_status;
+	int i;
+
+	/* update line status */
+	spin_lock_irqsave(&priv->lock, flags);
+	line_status = priv->line_status;
+	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	if (!urb->actual_length)
+		return;
+
+	/*
+	 * Break takes precedence over parity, which takes precedence over
+	 * framing errors.
+	 */
+	if (line_status & UART_BREAK_ERROR)
+		tty_flag = TTY_BREAK;
+	else if (line_status & UART_PARITY_ERROR)
+		tty_flag = TTY_PARITY;
+	else if (line_status & UART_FRAME_ERROR)
+		tty_flag = TTY_FRAME;
+
+	if (tty_flag != TTY_NORMAL)
+		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
+								tty_flag);
+	/* overrun is special, not associated with a char */
+	if (line_status & UART_OVERRUN_ERROR)
+		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
+
+	if (port->sysrq) {
+		for (i = 0; i < urb->actual_length; ++i)
+			if (!usb_serial_handle_sysrq_char(port, data[i]))
+				tty_insert_flip_char(&port->port, data[i],
+						tty_flag);
+	} else {
+		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
+							urb->actual_length);
+	}
+
+	tty_flip_buffer_push(&port->port);
+}
+
+static struct usb_serial_driver pl2303_device = {
+	.driver = {
+		.owner =	THIS_MODULE,
+		.name =		"pl2303",
+	},
+	.id_table =		id_table,
+	.num_bulk_in =		1,
+	.num_bulk_out =		1,
+	.num_interrupt_in =	0,	/* see pl2303_calc_num_ports */
+	.bulk_in_size =		256,
+	.bulk_out_size =	256,
+	.open =			pl2303_open,
+	.close =		pl2303_close,
+	.dtr_rts =		pl2303_dtr_rts,
+	.carrier_raised =	pl2303_carrier_raised,
+	.get_serial =		pl2303_get_serial,
+	.break_ctl =		pl2303_break_ctl,
+	.set_termios =		pl2303_set_termios,
+	.tiocmget =		pl2303_tiocmget,
+	.tiocmset =		pl2303_tiocmset,
+	.tiocmiwait =		usb_serial_generic_tiocmiwait,
+	.process_read_urb =	pl2303_process_read_urb,
+	.read_int_callback =	pl2303_read_int_callback,
+	.probe =		pl2303_probe,
+	.calc_num_ports =	pl2303_calc_num_ports,
+	.attach =		pl2303_startup,
+	.release =		pl2303_release,
+	.port_probe =		pl2303_port_probe,
+	.port_remove =		pl2303_port_remove,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&pl2303_device, NULL
+};
+
+module_usb_serial_driver(serial_drivers, id_table);
+
+MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
+MODULE_LICENSE("GPL v2");