USB: serial: add Fintek F81532/534 driver

This driver is for Fintek F81532/F81534 USB to Serial Ports IC.

F81532 spec:
https://drive.google.com/file/d/0B8vRwwYO7aMFOTRRMmhWQVNvajQ/view?usp=
sharing

F81534 spec:
https://drive.google.com/file/d/0B8vRwwYO7aMFV29pQWJqbVBNc00/view?usp=
sharing

Features:
1. F81532 is 1-to-2 & F81534 is 1-to-4 serial ports IC
2. Support Baudrate from B50 to B115200.

Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>

3 files changed, 1420 insertions, 0 deletions

diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig
index 56ecb8b5115d..d9bc8dafe000 100644
--- a/drivers/usb/serial/Kconfig
+++ b/drivers/usb/serial/Kconfig
@@ -255,6 +255,16 @@ config USB_SERIAL_F81232
 	  To compile this driver as a module, choose M here: the
 	  module will be called f81232.
 
+config USB_SERIAL_F8153X
+	tristate "USB Fintek F81532/534 Multi-Ports Serial Driver"
+	help
+	  Say Y here if you want to use the Fintek F81532/534 Multi-Ports
+	  USB to serial adapter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called f81534.
+
+
 config USB_SERIAL_GARMIN
        tristate "USB Garmin GPS driver"
        help
diff --git a/drivers/usb/serial/Makefile b/drivers/usb/serial/Makefile
index 349d9df0895f..9e43b7b002eb 100644
--- a/drivers/usb/serial/Makefile
+++ b/drivers/usb/serial/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_USB_SERIAL_EDGEPORT)		+= io_edgeport.o
 obj-$(CONFIG_USB_SERIAL_EDGEPORT_TI)		+= io_ti.o
 obj-$(CONFIG_USB_SERIAL_EMPEG)			+= empeg.o
 obj-$(CONFIG_USB_SERIAL_F81232)			+= f81232.o
+obj-$(CONFIG_USB_SERIAL_F8153X)			+= f81534.o
 obj-$(CONFIG_USB_SERIAL_FTDI_SIO)		+= ftdi_sio.o
 obj-$(CONFIG_USB_SERIAL_GARMIN)			+= garmin_gps.o
 obj-$(CONFIG_USB_SERIAL_IPAQ)			+= ipaq.o
diff --git a/drivers/usb/serial/f81534.c b/drivers/usb/serial/f81534.c
new file mode 100644
index 000000000000..8282a6a18fee
--- /dev/null
+++ b/drivers/usb/serial/f81534.c
@@ -0,0 +1,1409 @@
+/*
+ * F81532/F81534 USB to Serial Ports Bridge
+ *
+ * F81532 => 2 Serial Ports
+ * F81534 => 4 Serial Ports
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Copyright (C) 2016 Feature Integration Technology Inc., (Fintek)
+ * Copyright (C) 2016 Tom Tsai (Tom_Tsai@fintek.com.tw)
+ * Copyright (C) 2016 Peter Hong (Peter_Hong@fintek.com.tw)
+ *
+ * The F81532/F81534 had 1 control endpoint for setting, 1 endpoint bulk-out
+ * for all serial port TX and 1 endpoint bulk-in for all serial port read in
+ * (Read Data/MSR/LSR).
+ *
+ * Write URB is fixed with 512bytes, per serial port used 128Bytes.
+ * It can be described by f81534_prepare_write_buffer()
+ *
+ * Read URB is 512Bytes max, per serial port used 128Bytes.
+ * It can be described by f81534_process_read_urb() and maybe received with
+ * 128x1,2,3,4 bytes.
+ *
+ */
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <linux/serial_reg.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+
+/* Serial Port register Address */
+#define F81534_UART_BASE_ADDRESS	0x1200
+#define F81534_UART_OFFSET		0x10
+#define F81534_DIVISOR_LSB_REG		(0x00 + F81534_UART_BASE_ADDRESS)
+#define F81534_DIVISOR_MSB_REG		(0x01 + F81534_UART_BASE_ADDRESS)
+#define F81534_FIFO_CONTROL_REG		(0x02 + F81534_UART_BASE_ADDRESS)
+#define F81534_LINE_CONTROL_REG		(0x03 + F81534_UART_BASE_ADDRESS)
+#define F81534_MODEM_CONTROL_REG	(0x04 + F81534_UART_BASE_ADDRESS)
+#define F81534_MODEM_STATUS_REG		(0x06 + F81534_UART_BASE_ADDRESS)
+#define F81534_CONFIG1_REG		(0x09 + F81534_UART_BASE_ADDRESS)
+
+#define F81534_DEF_CONF_ADDRESS_START	0x3000
+#define F81534_DEF_CONF_SIZE		8
+
+#define F81534_CUSTOM_ADDRESS_START	0x2f00
+#define F81534_CUSTOM_DATA_SIZE		0x10
+#define F81534_CUSTOM_NO_CUSTOM_DATA	0xff
+#define F81534_CUSTOM_VALID_TOKEN	0xf0
+#define F81534_CONF_OFFSET		1
+
+#define F81534_MAX_DATA_BLOCK		64
+#define F81534_MAX_BUS_RETRY		20
+
+/* Default URB timeout for USB operations */
+#define F81534_USB_MAX_RETRY		10
+#define F81534_USB_TIMEOUT		1000
+#define F81534_SET_GET_REGISTER		0xA0
+
+#define F81534_NUM_PORT			4
+#define F81534_UNUSED_PORT		0xff
+#define F81534_WRITE_BUFFER_SIZE	512
+
+#define DRIVER_DESC			"Fintek F81532/F81534"
+#define FINTEK_VENDOR_ID_1		0x1934
+#define FINTEK_VENDOR_ID_2		0x2C42
+#define FINTEK_DEVICE_ID		0x1202
+#define F81534_MAX_TX_SIZE		124
+#define F81534_MAX_RX_SIZE		124
+#define F81534_RECEIVE_BLOCK_SIZE	128
+#define F81534_MAX_RECEIVE_BLOCK_SIZE	512
+
+#define F81534_TOKEN_RECEIVE		0x01
+#define F81534_TOKEN_WRITE		0x02
+#define F81534_TOKEN_TX_EMPTY		0x03
+#define F81534_TOKEN_MSR_CHANGE		0x04
+
+/*
+ * We used interal SPI bus to access FLASH section. We must wait the SPI bus to
+ * idle if we performed any command.
+ *
+ * SPI Bus status register: F81534_BUS_REG_STATUS
+ *	Bit 0/1	: BUSY
+ *	Bit 2	: IDLE
+ */
+#define F81534_BUS_BUSY			(BIT(0) | BIT(1))
+#define F81534_BUS_IDLE			BIT(2)
+#define F81534_BUS_READ_DATA		0x1004
+#define F81534_BUS_REG_STATUS		0x1003
+#define F81534_BUS_REG_START		0x1002
+#define F81534_BUS_REG_END		0x1001
+
+#define F81534_CMD_READ			0x03
+
+#define F81534_DEFAULT_BAUD_RATE	9600
+#define F81534_MAX_BAUDRATE		115200
+
+#define F81534_PORT_CONF_DISABLE_PORT	BIT(3)
+#define F81534_PORT_CONF_NOT_EXIST_PORT	BIT(7)
+#define F81534_PORT_UNAVAILABLE		\
+	(F81534_PORT_CONF_DISABLE_PORT | F81534_PORT_CONF_NOT_EXIST_PORT)
+
+#define F81534_1X_RXTRIGGER		0xc3
+#define F81534_8X_RXTRIGGER		0xcf
+
+static const struct usb_device_id f81534_id_table[] = {
+	{ USB_DEVICE(FINTEK_VENDOR_ID_1, FINTEK_DEVICE_ID) },
+	{ USB_DEVICE(FINTEK_VENDOR_ID_2, FINTEK_DEVICE_ID) },
+	{}			/* Terminating entry */
+};
+
+#define F81534_TX_EMPTY_BIT		0
+
+struct f81534_serial_private {
+	u8 conf_data[F81534_DEF_CONF_SIZE];
+	int tty_idx[F81534_NUM_PORT];
+	u8 setting_idx;
+	int opened_port;
+	struct mutex urb_mutex;
+};
+
+struct f81534_port_private {
+	struct mutex mcr_mutex;
+	unsigned long tx_empty;
+	spinlock_t msr_lock;
+	u8 shadow_mcr;
+	u8 shadow_msr;
+	u8 phy_num;
+};
+
+static int f81534_logic_to_phy_port(struct usb_serial *serial,
+					struct usb_serial_port *port)
+{
+	struct f81534_serial_private *serial_priv =
+			usb_get_serial_data(port->serial);
+	int count = 0;
+	int i;
+
+	for (i = 0; i < F81534_NUM_PORT; ++i) {
+		if (serial_priv->conf_data[i] & F81534_PORT_UNAVAILABLE)
+			continue;
+
+		if (port->port_number == count)
+			return i;
+
+		++count;
+	}
+
+	return -ENODEV;
+}
+
+static int f81534_set_register(struct usb_serial *serial, u16 reg, u8 data)
+{
+	struct usb_interface *interface = serial->interface;
+	struct usb_device *dev = serial->dev;
+	size_t count = F81534_USB_MAX_RETRY;
+	int status;
+	u8 *tmp;
+
+	tmp = kmalloc(sizeof(u8), GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
+
+	*tmp = data;
+
+	/*
+	 * Our device maybe not reply when heavily loading, We'll retry for
+	 * F81534_USB_MAX_RETRY times.
+	 */
+	while (count--) {
+		status = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+					 F81534_SET_GET_REGISTER,
+					 USB_TYPE_VENDOR | USB_DIR_OUT,
+					 reg, 0, tmp, sizeof(u8),
+					 F81534_USB_TIMEOUT);
+		if (status > 0) {
+			status = 0;
+			break;
+		} else if (status == 0) {
+			status = -EIO;
+		}
+	}
+
+	if (status < 0) {
+		dev_err(&interface->dev, "%s: reg: %x data: %x failed: %d\n",
+				__func__, reg, data, status);
+	}
+
+	kfree(tmp);
+	return status;
+}
+
+static int f81534_get_register(struct usb_serial *serial, u16 reg, u8 *data)
+{
+	struct usb_interface *interface = serial->interface;
+	struct usb_device *dev = serial->dev;
+	size_t count = F81534_USB_MAX_RETRY;
+	int status;
+	u8 *tmp;
+
+	tmp = kmalloc(sizeof(u8), GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
+
+	/*
+	 * Our device maybe not reply when heavily loading, We'll retry for
+	 * F81534_USB_MAX_RETRY times.
+	 */
+	while (count--) {
+		status = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
+					 F81534_SET_GET_REGISTER,
+					 USB_TYPE_VENDOR | USB_DIR_IN,
+					 reg, 0, tmp, sizeof(u8),
+					 F81534_USB_TIMEOUT);
+		if (status > 0) {
+			status = 0;
+			break;
+		} else if (status == 0) {
+			status = -EIO;
+		}
+	}
+
+	if (status < 0) {
+		dev_err(&interface->dev, "%s: reg: %x failed: %d\n", __func__,
+				reg, status);
+		goto end;
+	}
+
+	*data = *tmp;
+
+end:
+	kfree(tmp);
+	return status;
+}
+
+static int f81534_set_port_register(struct usb_serial_port *port, u16 reg,
+					u8 data)
+{
+	struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
+
+	return f81534_set_register(port->serial,
+			reg + port_priv->phy_num * F81534_UART_OFFSET, data);
+}
+
+static int f81534_get_port_register(struct usb_serial_port *port, u16 reg,
+					u8 *data)
+{
+	struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
+
+	return f81534_get_register(port->serial,
+			reg + port_priv->phy_num * F81534_UART_OFFSET, data);
+}
+
+/*
+ * If we try to access the internal flash via SPI bus, we should check the bus
+ * status for every command. e.g., F81534_BUS_REG_START/F81534_BUS_REG_END
+ */
+static int f81534_wait_for_spi_idle(struct usb_serial *serial)
+{
+	size_t count = F81534_MAX_BUS_RETRY;
+	u8 tmp;
+	int status;
+
+	do {
+		status = f81534_get_register(serial, F81534_BUS_REG_STATUS,
+						&tmp);
+		if (status)
+			return status;
+
+		if (tmp & F81534_BUS_BUSY)
+			continue;
+
+		if (tmp & F81534_BUS_IDLE)
+			break;
+
+	} while (--count);
+
+	if (!count) {
+		dev_err(&serial->interface->dev,
+				"%s: timed out waiting for idle SPI bus\n",
+				__func__);
+		return -EIO;
+	}
+
+	return f81534_set_register(serial, F81534_BUS_REG_STATUS,
+				tmp & ~F81534_BUS_IDLE);
+}
+
+static int f81534_get_spi_register(struct usb_serial *serial, u16 reg,
+					u8 *data)
+{
+	int status;
+
+	status = f81534_get_register(serial, reg, data);
+	if (status)
+		return status;
+
+	return f81534_wait_for_spi_idle(serial);
+}
+
+static int f81534_set_spi_register(struct usb_serial *serial, u16 reg, u8 data)
+{
+	int status;
+
+	status = f81534_set_register(serial, reg, data);
+	if (status)
+		return status;
+
+	return f81534_wait_for_spi_idle(serial);
+}
+
+static int f81534_read_flash(struct usb_serial *serial, u32 address,
+				size_t size, u8 *buf)
+{
+	u8 tmp_buf[F81534_MAX_DATA_BLOCK];
+	size_t block = 0;
+	size_t read_size;
+	size_t count;
+	int status;
+	int offset;
+	u16 reg_tmp;
+
+	status = f81534_set_spi_register(serial, F81534_BUS_REG_START,
+					F81534_CMD_READ);
+	if (status)
+		return status;
+
+	status = f81534_set_spi_register(serial, F81534_BUS_REG_START,
+					(address >> 16) & 0xff);
+	if (status)
+		return status;
+
+	status = f81534_set_spi_register(serial, F81534_BUS_REG_START,
+					(address >> 8) & 0xff);
+	if (status)
+		return status;
+
+	status = f81534_set_spi_register(serial, F81534_BUS_REG_START,
+					(address >> 0) & 0xff);
+	if (status)
+		return status;
+
+	/* Continuous read mode */
+	do {
+		read_size = min_t(size_t, F81534_MAX_DATA_BLOCK, size);
+
+		for (count = 0; count < read_size; ++count) {
+			/* To write F81534_BUS_REG_END when final byte */
+			if (size <= F81534_MAX_DATA_BLOCK &&
+					read_size == count + 1)
+				reg_tmp = F81534_BUS_REG_END;
+			else
+				reg_tmp = F81534_BUS_REG_START;
+
+			/*
+			 * Dummy code, force IC to generate a read pulse, the
+			 * set of value 0xf1 is dont care (any value is ok)
+			 */
+			status = f81534_set_spi_register(serial, reg_tmp,
+					0xf1);
+			if (status)
+				return status;
+
+			status = f81534_get_spi_register(serial,
+						F81534_BUS_READ_DATA,
+						&tmp_buf[count]);
+			if (status)
+				return status;
+
+			offset = count + block * F81534_MAX_DATA_BLOCK;
+			buf[offset] = tmp_buf[count];
+		}
+
+		size -= read_size;
+		++block;
+	} while (size);
+
+	return 0;
+}
+
+static void f81534_prepare_write_buffer(struct usb_serial_port *port, u8 *buf)
+{
+	struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
+	int phy_num = port_priv->phy_num;
+	u8 tx_len;
+	int i;
+
+	/*
+	 * The block layout is fixed with 4x128 Bytes, per 128 Bytes a port.
+	 * index 0: port phy idx (e.g., 0,1,2,3)
+	 * index 1: only F81534_TOKEN_WRITE
+	 * index 2: serial TX out length
+	 * index 3: fix to 0
+	 * index 4~127: serial out data block
+	 */
+	for (i = 0; i < F81534_NUM_PORT; ++i) {
+		buf[i * F81534_RECEIVE_BLOCK_SIZE] = i;
+		buf[i * F81534_RECEIVE_BLOCK_SIZE + 1] = F81534_TOKEN_WRITE;
+		buf[i * F81534_RECEIVE_BLOCK_SIZE + 2] = 0;
+		buf[i * F81534_RECEIVE_BLOCK_SIZE + 3] = 0;
+	}
+
+	tx_len = kfifo_out_locked(&port->write_fifo,
+				&buf[phy_num * F81534_RECEIVE_BLOCK_SIZE + 4],
+				F81534_MAX_TX_SIZE, &port->lock);
+
+	buf[phy_num * F81534_RECEIVE_BLOCK_SIZE + 2] = tx_len;
+}
+
+static int f81534_submit_writer(struct usb_serial_port *port, gfp_t mem_flags)
+{
+	struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
+	struct urb *urb;
+	unsigned long flags;
+	int result;
+
+	/* Check is any data in write_fifo */
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (kfifo_is_empty(&port->write_fifo)) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		return 0;
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/* Check H/W is TXEMPTY */
+	if (!test_and_clear_bit(F81534_TX_EMPTY_BIT, &port_priv->tx_empty))
+		return 0;
+
+	urb = port->write_urbs[0];
+	f81534_prepare_write_buffer(port, port->bulk_out_buffers[0]);
+	urb->transfer_buffer_length = F81534_WRITE_BUFFER_SIZE;
+
+	result = usb_submit_urb(urb, mem_flags);
+	if (result) {
+		set_bit(F81534_TX_EMPTY_BIT, &port_priv->tx_empty);
+		dev_err(&port->dev, "%s: submit failed: %d\n", __func__,
+				result);
+		return result;
+	}
+
+	usb_serial_port_softint(port);
+	return 0;
+}
+
+static u32 f81534_calc_baud_divisor(u32 baudrate, u32 clockrate)
+{
+	if (!baudrate)
+		return 0;
+
+	/* Round to nearest divisor */
+	return DIV_ROUND_CLOSEST(clockrate, baudrate);
+}
+
+static int f81534_set_port_config(struct usb_serial_port *port, u32 baudrate,
+					u8 lcr)
+{
+	u32 divisor;
+	int status;
+	u8 value;
+
+	if (baudrate <= 1200)
+		value = F81534_1X_RXTRIGGER;	/* 128 FIFO & TL: 1x */
+	else
+		value = F81534_8X_RXTRIGGER;	/* 128 FIFO & TL: 8x */
+
+	status = f81534_set_port_register(port, F81534_CONFIG1_REG, value);
+	if (status) {
+		dev_err(&port->dev, "%s: CONFIG1 setting failed\n", __func__);
+		return status;
+	}
+
+	if (baudrate <= 1200)
+		value = UART_FCR_TRIGGER_1 | UART_FCR_ENABLE_FIFO; /* TL: 1 */
+	else
+		value = UART_FCR_R_TRIG_11 | UART_FCR_ENABLE_FIFO; /* TL: 14 */
+
+	status = f81534_set_port_register(port, F81534_FIFO_CONTROL_REG,
+						value);
+	if (status) {
+		dev_err(&port->dev, "%s: FCR setting failed\n", __func__);
+		return status;
+	}
+
+	divisor = f81534_calc_baud_divisor(baudrate, F81534_MAX_BAUDRATE);
+	value = UART_LCR_DLAB;
+	status = f81534_set_port_register(port, F81534_LINE_CONTROL_REG,
+						value);
+	if (status) {
+		dev_err(&port->dev, "%s: set LCR failed\n", __func__);
+		return status;
+	}
+
+	value = divisor & 0xff;
+	status = f81534_set_port_register(port, F81534_DIVISOR_LSB_REG, value);
+	if (status) {
+		dev_err(&port->dev, "%s: set DLAB LSB failed\n", __func__);
+		return status;
+	}
+
+	value = (divisor >> 8) & 0xff;
+	status = f81534_set_port_register(port, F81534_DIVISOR_MSB_REG, value);
+	if (status) {
+		dev_err(&port->dev, "%s: set DLAB MSB failed\n", __func__);
+		return status;
+	}
+
+	status = f81534_set_port_register(port, F81534_LINE_CONTROL_REG, lcr);
+	if (status) {
+		dev_err(&port->dev, "%s: set LCR failed\n", __func__);
+		return status;
+	}
+
+	return 0;
+}
+
+static int f81534_update_mctrl(struct usb_serial_port *port, unsigned int set,
+				unsigned int clear)
+{
+	struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
+	int status;
+	u8 tmp;
+
+	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0)
+		return 0;	/* no change */
+
+	mutex_lock(&port_priv->mcr_mutex);
+
+	/* 'Set' takes precedence over 'Clear' */
+	clear &= ~set;
+
+	/* Always enable UART_MCR_OUT2 */
+	tmp = UART_MCR_OUT2 | port_priv->shadow_mcr;
+
+	if (clear & TIOCM_DTR)
+		tmp &= ~UART_MCR_DTR;
+
+	if (clear & TIOCM_RTS)
+		tmp &= ~UART_MCR_RTS;
+
+	if (set & TIOCM_DTR)
+		tmp |= UART_MCR_DTR;
+
+	if (set & TIOCM_RTS)
+		tmp |= UART_MCR_RTS;
+
+	status = f81534_set_port_register(port, F81534_MODEM_CONTROL_REG, tmp);
+	if (status < 0) {
+		dev_err(&port->dev, "%s: MCR write failed\n", __func__);
+		mutex_unlock(&port_priv->mcr_mutex);
+		return status;
+	}
+
+	port_priv->shadow_mcr = tmp;
+	mutex_unlock(&port_priv->mcr_mutex);
+	return 0;
+}
+
+/*
+ * This function will search the data area with token F81534_CUSTOM_VALID_TOKEN
+ * for latest configuration index. If nothing found
+ * (*index = F81534_CUSTOM_NO_CUSTOM_DATA), We'll load default configure in
+ * F81534_DEF_CONF_ADDRESS_START section.
+ *
+ * Due to we only use block0 to save data, so *index should be 0 or
+ * F81534_CUSTOM_NO_CUSTOM_DATA.
+ */
+static int f81534_find_config_idx(struct usb_serial *serial, u8 *index)
+{
+	u8 tmp;
+	int status;
+
+	status = f81534_read_flash(serial, F81534_CUSTOM_ADDRESS_START, 1,
+					&tmp);
+	if (status) {
+		dev_err(&serial->interface->dev, "%s: read failed: %d\n",
+				__func__, status);
+		return status;
+	}
+
+	/* We'll use the custom data when the data is valid. */
+	if (tmp == F81534_CUSTOM_VALID_TOKEN)
+		*index = 0;
+	else
+		*index = F81534_CUSTOM_NO_CUSTOM_DATA;
+
+	return 0;
+}
+
+/*
+ * We had 2 generation of F81532/534 IC. All has an internal storage.
+ *
+ * 1st is pure USB-to-TTL RS232 IC and designed for 4 ports only, no any
+ * internal data will used. All mode and gpio control should manually set
+ * by AP or Driver and all storage space value are 0xff. The
+ * f81534_calc_num_ports() will run to final we marked as "oldest version"
+ * for this IC.
+ *
+ * 2rd is designed to more generic to use any transceiver and this is our
+ * mass production type. We'll save data in F81534_CUSTOM_ADDRESS_START
+ * (0x2f00) with 9bytes. The 1st byte is a indicater. If the token is
+ * F81534_CUSTOM_VALID_TOKEN(0xf0), the IC is 2nd gen type, the following
+ * 4bytes save port mode (0:RS232/1:RS485 Invert/2:RS485), and the last
+ * 4bytes save GPIO state(value from 0~7 to represent 3 GPIO output pin).
+ * The f81534_calc_num_ports() will run to "new style" with checking
+ * F81534_PORT_UNAVAILABLE section.
+ */
+static int f81534_calc_num_ports(struct usb_serial *serial)
+{
+	u8 setting[F81534_CUSTOM_DATA_SIZE];
+	u8 setting_idx;
+	u8 num_port = 0;
+	int status;
+	size_t i;
+
+	/* Check had custom setting */
+	status = f81534_find_config_idx(serial, &setting_idx);
+	if (status) {
+		dev_err(&serial->interface->dev, "%s: find idx failed: %d\n",
+				__func__, status);
+		return 0;
+	}
+
+	/*
+	 * We'll read custom data only when data available, otherwise we'll
+	 * read default value instead.
+	 */
+	if (setting_idx != F81534_CUSTOM_NO_CUSTOM_DATA) {
+		status = f81534_read_flash(serial,
+						F81534_CUSTOM_ADDRESS_START +
+						F81534_CONF_OFFSET,
+						sizeof(setting), setting);
+		if (status) {
+			dev_err(&serial->interface->dev,
+					"%s: get custom data failed: %d\n",
+					__func__, status);
+			return 0;
+		}
+
+		dev_dbg(&serial->interface->dev,
+				"%s: read config from block: %d\n", __func__,
+				setting_idx);
+	} else {
+		/* Read default board setting */
+		status = f81534_read_flash(serial,
+				F81534_DEF_CONF_ADDRESS_START, F81534_NUM_PORT,
+				setting);
+
+		if (status) {
+			dev_err(&serial->interface->dev,
+					"%s: read failed: %d\n", __func__,
+					status);
+			return 0;
+		}
+
+		dev_dbg(&serial->interface->dev, "%s: read default config\n",
+				__func__);
+	}
+
+	/* New style, find all possible ports */
+	for (i = 0; i < F81534_NUM_PORT; ++i) {
+		if (setting[i] & F81534_PORT_UNAVAILABLE)
+			continue;
+
+		++num_port;
+	}
+
+	if (num_port)
+		return num_port;
+
+	dev_warn(&serial->interface->dev, "%s: Read Failed. default 4 ports\n",
+			__func__);
+	return 4;		/* Nothing found, oldest version IC */
+}
+
+static void f81534_set_termios(struct tty_struct *tty,
+				struct usb_serial_port *port,
+				struct ktermios *old_termios)
+{
+	u8 new_lcr = 0;
+	int status;
+	u32 baud;
+
+	if (C_BAUD(tty) == B0)
+		f81534_update_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
+	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
+		f81534_update_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
+
+	if (C_PARENB(tty)) {
+		new_lcr |= UART_LCR_PARITY;
+
+		if (!C_PARODD(tty))
+			new_lcr |= UART_LCR_EPAR;
+
+		if (C_CMSPAR(tty))
+			new_lcr |= UART_LCR_SPAR;
+	}
+
+	if (C_CSTOPB(tty))
+		new_lcr |= UART_LCR_STOP;
+
+	switch (C_CSIZE(tty)) {
+	case CS5:
+		new_lcr |= UART_LCR_WLEN5;
+		break;
+	case CS6:
+		new_lcr |= UART_LCR_WLEN6;
+		break;
+	case CS7:
+		new_lcr |= UART_LCR_WLEN7;
+		break;
+	default:
+	case CS8:
+		new_lcr |= UART_LCR_WLEN8;
+		break;
+	}
+
+	baud = tty_get_baud_rate(tty);
+	if (!baud)
+		return;
+
+	if (baud > F81534_MAX_BAUDRATE) {
+		if (old_termios)
+			baud = tty_termios_baud_rate(old_termios);
+		else
+			baud = F81534_DEFAULT_BAUD_RATE;
+
+		tty_encode_baud_rate(tty, baud, baud);
+	}
+
+	dev_dbg(&port->dev, "%s: baud: %d\n", __func__, baud);
+
+	status = f81534_set_port_config(port, baud, new_lcr);
+	if (status < 0) {
+		dev_err(&port->dev, "%s: set port config failed: %d\n",
+				__func__, status);
+	}
+}
+
+static int f81534_submit_read_urb(struct usb_serial *serial, gfp_t flags)
+{
+	return usb_serial_generic_submit_read_urbs(serial->port[0], flags);
+}
+
+static void f81534_msr_changed(struct usb_serial_port *port, u8 msr)
+{
+	struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
+	struct tty_struct *tty;
+	unsigned long flags;
+	u8 old_msr;
+
+	if (!(msr & UART_MSR_ANY_DELTA))
+		return;
+
+	spin_lock_irqsave(&port_priv->msr_lock, flags);
+	old_msr = port_priv->shadow_msr;
+	port_priv->shadow_msr = msr;
+	spin_unlock_irqrestore(&port_priv->msr_lock, flags);
+
+	dev_dbg(&port->dev, "%s: MSR from %02x to %02x\n", __func__, old_msr,
+			msr);
+
+	/* Update input line counters */
+	if (msr & UART_MSR_DCTS)
+		port->icount.cts++;
+	if (msr & UART_MSR_DDSR)
+		port->icount.dsr++;
+	if (msr & UART_MSR_DDCD)
+		port->icount.dcd++;
+	if (msr & UART_MSR_TERI)
+		port->icount.rng++;
+
+	wake_up_interruptible(&port->port.delta_msr_wait);
+
+	if (!(msr & UART_MSR_DDCD))
+		return;
+
+	dev_dbg(&port->dev, "%s: DCD Changed: phy_num: %d from %x to %x\n",
+			__func__, port_priv->phy_num, old_msr, msr);
+
+	tty = tty_port_tty_get(&port->port);
+	if (!tty)
+		return;
+
+	usb_serial_handle_dcd_change(port, tty, msr & UART_MSR_DCD);
+	tty_kref_put(tty);
+}
+
+static int f81534_read_msr(struct usb_serial_port *port)
+{
+	struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	int status;
+	u8 msr;
+
+	/* Get MSR initial value */
+	status = f81534_get_port_register(port, F81534_MODEM_STATUS_REG, &msr);
+	if (status)
+		return status;
+
+	/* Force update current state */
+	spin_lock_irqsave(&port_priv->msr_lock, flags);
+	port_priv->shadow_msr = msr;
+	spin_unlock_irqrestore(&port_priv->msr_lock, flags);
+
+	return 0;
+}
+
+static int f81534_open(struct tty_struct *tty, struct usb_serial_port *port)
+{
+	struct f81534_serial_private *serial_priv =
+			usb_get_serial_data(port->serial);
+	struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
+	int status;
+
+	status = f81534_set_port_register(port,
+				F81534_FIFO_CONTROL_REG, UART_FCR_ENABLE_FIFO |
+				UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+	if (status) {
+		dev_err(&port->dev, "%s: Clear FIFO failed: %d\n", __func__,
+				status);
+		return status;
+	}
+
+	if (tty)
+		f81534_set_termios(tty, port, NULL);
+
+	status = f81534_read_msr(port);
+	if (status)
+		return status;
+
+	mutex_lock(&serial_priv->urb_mutex);
+
+	/* Submit Read URBs for first port opened */
+	if (!serial_priv->opened_port) {
+		status = f81534_submit_read_urb(port->serial, GFP_KERNEL);
+		if (status)
+			goto exit;
+	}
+
+	serial_priv->opened_port++;
+
+exit:
+	mutex_unlock(&serial_priv->urb_mutex);
+
+	set_bit(F81534_TX_EMPTY_BIT, &port_priv->tx_empty);
+	return status;
+}
+
+static void f81534_close(struct usb_serial_port *port)
+{
+	struct f81534_serial_private *serial_priv =
+			usb_get_serial_data(port->serial);
+	struct usb_serial_port *port0 = port->serial->port[0];
+	unsigned long flags;
+	size_t i;
+
+	usb_kill_urb(port->write_urbs[0]);
+
+	spin_lock_irqsave(&port->lock, flags);
+	kfifo_reset_out(&port->write_fifo);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/* Kill Read URBs when final port closed */
+	mutex_lock(&serial_priv->urb_mutex);
+	serial_priv->opened_port--;
+
+	if (!serial_priv->opened_port) {
+		for (i = 0; i < ARRAY_SIZE(port0->read_urbs); ++i)
+			usb_kill_urb(port0->read_urbs[i]);
+	}
+
+	mutex_unlock(&serial_priv->urb_mutex);
+}
+
+static int f81534_get_serial_info(struct usb_serial_port *port,
+				  struct serial_struct __user *retinfo)
+{
+	struct f81534_port_private *port_priv;
+	struct serial_struct tmp;
+
+	port_priv = usb_get_serial_port_data(port);
+
+	memset(&tmp, 0, sizeof(tmp));
+
+	tmp.type = PORT_16550A;
+	tmp.port = port->port_number;
+	tmp.line = port->minor;
+	tmp.baud_base = F81534_MAX_BAUDRATE;
+
+	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int f81534_ioctl(struct tty_struct *tty, unsigned int cmd,
+			unsigned long arg)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct serial_struct __user *buf = (struct serial_struct __user *)arg;
+
+	switch (cmd) {
+	case TIOCGSERIAL:
+		return f81534_get_serial_info(port, buf);
+	default:
+		break;
+	}
+
+	return -ENOIOCTLCMD;
+}
+
+static void f81534_process_per_serial_block(struct usb_serial_port *port,
+		u8 *data)
+{
+	struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
+	int phy_num = data[0];
+	size_t read_size = 0;
+	size_t i;
+	char tty_flag;
+	int status;
+	u8 lsr;
+
+	/*
+	 * The block layout is 128 Bytes
+	 * index 0: port phy idx (e.g., 0,1,2,3),
+	 * index 1: It's could be
+	 *			F81534_TOKEN_RECEIVE
+	 *			F81534_TOKEN_TX_EMPTY
+	 *			F81534_TOKEN_MSR_CHANGE
+	 * index 2: serial in size (data+lsr, must be even)
+	 *			meaningful for F81534_TOKEN_RECEIVE only
+	 * index 3: current MSR with this device
+	 * index 4~127: serial in data block (data+lsr, must be even)
+	 */
+	switch (data[1]) {
+	case F81534_TOKEN_TX_EMPTY:
+		set_bit(F81534_TX_EMPTY_BIT, &port_priv->tx_empty);
+
+		/* Try to submit writer */
+		status = f81534_submit_writer(port, GFP_ATOMIC);
+		if (status)
+			dev_err(&port->dev, "%s: submit failed\n", __func__);
+		return;
+
+	case F81534_TOKEN_MSR_CHANGE:
+		f81534_msr_changed(port, data[3]);
+		return;
+
+	case F81534_TOKEN_RECEIVE:
+		read_size = data[2];
+		if (read_size > F81534_MAX_RX_SIZE) {
+			dev_err(&port->dev,
+				"%s: phy: %d read_size: %zu larger than: %d\n",
+				__func__, phy_num, read_size,
+				F81534_MAX_RX_SIZE);
+			return;
+		}
+
+		break;
+
+	default:
+		dev_warn(&port->dev, "%s: unknown token: %02x\n", __func__,
+				data[1]);
+		return;
+	}
+
+	for (i = 4; i < 4 + read_size; i += 2) {
+		tty_flag = TTY_NORMAL;
+		lsr = data[i + 1];
+
+		if (lsr & UART_LSR_BRK_ERROR_BITS) {
+			if (lsr & UART_LSR_BI) {
+				tty_flag = TTY_BREAK;
+				port->icount.brk++;
+				usb_serial_handle_break(port);
+			} else if (lsr & UART_LSR_PE) {
+				tty_flag = TTY_PARITY;
+				port->icount.parity++;
+			} else if (lsr & UART_LSR_FE) {
+				tty_flag = TTY_FRAME;
+				port->icount.frame++;
+			}
+
+			if (lsr & UART_LSR_OE) {
+				port->icount.overrun++;
+				tty_insert_flip_char(&port->port, 0,
+						TTY_OVERRUN);
+			}
+		}
+
+		if (port->port.console && port->sysrq) {
+			if (usb_serial_handle_sysrq_char(port, data[i]))
+				continue;
+		}
+
+		tty_insert_flip_char(&port->port, data[i], tty_flag);
+	}
+
+	tty_flip_buffer_push(&port->port);
+}
+
+static void f81534_process_read_urb(struct urb *urb)
+{
+	struct f81534_serial_private *serial_priv;
+	struct usb_serial_port *port;
+	struct usb_serial *serial;
+	u8 *buf;
+	int phy_port_num;
+	int tty_port_num;
+	size_t i;
+
+	if (!urb->actual_length ||
+			urb->actual_length % F81534_RECEIVE_BLOCK_SIZE) {
+		return;
+	}
+
+	port = urb->context;
+	serial = port->serial;
+	buf = urb->transfer_buffer;
+	serial_priv = usb_get_serial_data(serial);
+
+	for (i = 0; i < urb->actual_length; i += F81534_RECEIVE_BLOCK_SIZE) {
+		phy_port_num = buf[i];
+		if (phy_port_num >= F81534_NUM_PORT) {
+			dev_err(&port->dev,
+				"%s: phy_port_num: %d larger than: %d\n",
+				__func__, phy_port_num, F81534_NUM_PORT);
+			continue;
+		}
+
+		tty_port_num = serial_priv->tty_idx[phy_port_num];
+		port = serial->port[tty_port_num];
+
+		if (tty_port_initialized(&port->port))
+			f81534_process_per_serial_block(port, &buf[i]);
+	}
+}
+
+static void f81534_write_usb_callback(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+
+	switch (urb->status) {
+	case 0:
+		break;
+	case -ENOENT:
+	case -ECONNRESET:
+	case -ESHUTDOWN:
+		dev_dbg(&port->dev, "%s - urb stopped: %d\n",
+				__func__, urb->status);
+		return;
+	case -EPIPE:
+		dev_err(&port->dev, "%s - urb stopped: %d\n",
+				__func__, urb->status);
+		return;
+	default:
+		dev_dbg(&port->dev, "%s - nonzero urb status: %d\n",
+				__func__, urb->status);
+		break;
+	}
+}
+
+static int f81534_setup_ports(struct usb_serial *serial)
+{
+	struct usb_serial_port *port;
+	u8 port0_out_address;
+	int buffer_size;
+	size_t i;
+
+	/*
+	 * In our system architecture, we had 2 or 4 serial ports,
+	 * but only get 1 set of bulk in/out endpoints.
+	 *
+	 * The usb-serial subsystem will generate port 0 data,
+	 * but port 1/2/3 will not. It's will generate write URB and buffer
+	 * by following code and use the port0 read URB for read operation.
+	 */
+	for (i = 1; i < serial->num_ports; ++i) {
+		port0_out_address = serial->port[0]->bulk_out_endpointAddress;
+		buffer_size = serial->port[0]->bulk_out_size;
+		port = serial->port[i];
+
+		if (kfifo_alloc(&port->write_fifo, PAGE_SIZE, GFP_KERNEL))
+			return -ENOMEM;
+
+		port->bulk_out_size = buffer_size;
+		port->bulk_out_endpointAddress = port0_out_address;
+
+		port->write_urbs[0] = usb_alloc_urb(0, GFP_KERNEL);
+		if (!port->write_urbs[0])
+			return -ENOMEM;
+
+		port->bulk_out_buffers[0] = kzalloc(buffer_size, GFP_KERNEL);
+		if (!port->bulk_out_buffers[0])
+			return -ENOMEM;
+
+		usb_fill_bulk_urb(port->write_urbs[0], serial->dev,
+				usb_sndbulkpipe(serial->dev,
+					port0_out_address),
+				port->bulk_out_buffers[0], buffer_size,
+				serial->type->write_bulk_callback, port);
+
+		port->write_urb = port->write_urbs[0];
+		port->bulk_out_buffer = port->bulk_out_buffers[0];
+	}
+
+	return 0;
+}
+
+static int f81534_probe(struct usb_serial *serial,
+					const struct usb_device_id *id)
+{
+	struct usb_endpoint_descriptor *endpoint;
+	struct usb_host_interface *iface_desc;
+	struct device *dev;
+	int num_bulk_in = 0;
+	int num_bulk_out = 0;
+	int size_bulk_in = 0;
+	int size_bulk_out = 0;
+	int i;
+
+	dev = &serial->interface->dev;
+	iface_desc = serial->interface->cur_altsetting;
+
+	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+		endpoint = &iface_desc->endpoint[i].desc;
+
+		if (usb_endpoint_is_bulk_in(endpoint)) {
+			++num_bulk_in;
+			size_bulk_in = usb_endpoint_maxp(endpoint);
+		}
+
+		if (usb_endpoint_is_bulk_out(endpoint)) {
+			++num_bulk_out;
+			size_bulk_out = usb_endpoint_maxp(endpoint);
+		}
+	}
+
+	if (num_bulk_in != 1 || num_bulk_out != 1) {
+		dev_err(dev, "expected endpoints not found\n");
+		return -ENODEV;
+	}
+
+	if (size_bulk_out != F81534_WRITE_BUFFER_SIZE ||
+			size_bulk_in != F81534_MAX_RECEIVE_BLOCK_SIZE) {
+		dev_err(dev, "unsupported endpoint max packet size\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int f81534_attach(struct usb_serial *serial)
+{
+	struct f81534_serial_private *serial_priv;
+	int index = 0;
+	int status;
+	int i;
+
+	serial_priv = devm_kzalloc(&serial->interface->dev,
+					sizeof(*serial_priv), GFP_KERNEL);
+	if (!serial_priv)
+		return -ENOMEM;
+
+	usb_set_serial_data(serial, serial_priv);
+
+	mutex_init(&serial_priv->urb_mutex);
+
+	status = f81534_setup_ports(serial);
+	if (status)
+		return status;
+
+	/* Check had custom setting */
+	status = f81534_find_config_idx(serial, &serial_priv->setting_idx);
+	if (status) {
+		dev_err(&serial->interface->dev, "%s: find idx failed: %d\n",
+				__func__, status);
+		return status;
+	}
+
+	/*
+	 * We'll read custom data only when data available, otherwise we'll
+	 * read default value instead.
+	 */
+	if (serial_priv->setting_idx == F81534_CUSTOM_NO_CUSTOM_DATA) {
+		/*
+		 * The default configuration layout:
+		 *	byte 0/1/2/3: uart setting
+		 */
+		status = f81534_read_flash(serial,
+					F81534_DEF_CONF_ADDRESS_START,
+					F81534_DEF_CONF_SIZE,
+					serial_priv->conf_data);
+		if (status) {
+			dev_err(&serial->interface->dev,
+					"%s: read reserve data failed: %d\n",
+					__func__, status);
+			return status;
+		}
+	} else {
+		/* Only read 8 bytes for mode & GPIO */
+		status = f81534_read_flash(serial,
+						F81534_CUSTOM_ADDRESS_START +
+						F81534_CONF_OFFSET,
+						sizeof(serial_priv->conf_data),
+						serial_priv->conf_data);
+		if (status) {
+			dev_err(&serial->interface->dev,
+					"%s: idx: %d get data failed: %d\n",
+					__func__, serial_priv->setting_idx,
+					status);
+			return status;
+		}
+	}
+
+	/* Assign phy-to-logic mapping */
+	for (i = 0; i < F81534_NUM_PORT; ++i) {
+		if (serial_priv->conf_data[i] & F81534_PORT_UNAVAILABLE)
+			continue;
+
+		serial_priv->tty_idx[i] = index++;
+		dev_dbg(&serial->interface->dev,
+				"%s: phy_num: %d, tty_idx: %d\n", __func__, i,
+				serial_priv->tty_idx[i]);
+	}
+
+	return 0;
+}
+
+static int f81534_port_probe(struct usb_serial_port *port)
+{
+	struct f81534_port_private *port_priv;
+
+	port_priv = devm_kzalloc(&port->dev, sizeof(*port_priv), GFP_KERNEL);
+	if (!port_priv)
+		return -ENOMEM;
+
+	spin_lock_init(&port_priv->msr_lock);
+	mutex_init(&port_priv->mcr_mutex);
+
+	/* Assign logic-to-phy mapping */
+	port_priv->phy_num = f81534_logic_to_phy_port(port->serial, port);
+	if (port_priv->phy_num < 0 || port_priv->phy_num >= F81534_NUM_PORT)
+		return -ENODEV;
+
+	usb_set_serial_port_data(port, port_priv);
+	dev_dbg(&port->dev, "%s: port_number: %d, phy_num: %d\n", __func__,
+			port->port_number, port_priv->phy_num);
+
+	return 0;
+}
+
+static int f81534_tiocmget(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
+	int status;
+	int r;
+	u8 msr;
+	u8 mcr;
+
+	/* Read current MSR from device */
+	status = f81534_get_port_register(port, F81534_MODEM_STATUS_REG, &msr);
+	if (status)
+		return status;
+
+	mutex_lock(&port_priv->mcr_mutex);
+	mcr = port_priv->shadow_mcr;
+	mutex_unlock(&port_priv->mcr_mutex);
+
+	r = (mcr & UART_MCR_DTR ? TIOCM_DTR : 0) |
+	    (mcr & UART_MCR_RTS ? TIOCM_RTS : 0) |
+	    (msr & UART_MSR_CTS ? TIOCM_CTS : 0) |
+	    (msr & UART_MSR_DCD ? TIOCM_CAR : 0) |
+	    (msr & UART_MSR_RI ? TIOCM_RI : 0) |
+	    (msr & UART_MSR_DSR ? TIOCM_DSR : 0);
+
+	return r;
+}
+
+static int f81534_tiocmset(struct tty_struct *tty, unsigned int set,
+				unsigned int clear)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	return f81534_update_mctrl(port, set, clear);
+}
+
+static void f81534_dtr_rts(struct usb_serial_port *port, int on)
+{
+	if (on)
+		f81534_update_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
+	else
+		f81534_update_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
+}
+
+static int f81534_write(struct tty_struct *tty, struct usb_serial_port *port,
+			const u8 *buf, int count)
+{
+	int bytes_out, status;
+
+	if (!count)
+		return 0;
+
+	bytes_out = kfifo_in_locked(&port->write_fifo, buf, count,
+					&port->lock);
+
+	status = f81534_submit_writer(port, GFP_ATOMIC);
+	if (status) {
+		dev_err(&port->dev, "%s: submit failed\n", __func__);
+		return status;
+	}
+
+	return bytes_out;
+}
+
+static bool f81534_tx_empty(struct usb_serial_port *port)
+{
+	struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
+
+	return test_bit(F81534_TX_EMPTY_BIT, &port_priv->tx_empty);
+}
+
+static int f81534_resume(struct usb_serial *serial)
+{
+	struct f81534_serial_private *serial_priv =
+			usb_get_serial_data(serial);
+	struct usb_serial_port *port;
+	int error = 0;
+	int status;
+	size_t i;
+
+	/*
+	 * We'll register port 0 bulkin when port had opened, It'll take all
+	 * port received data, MSR register change and TX_EMPTY information.
+	 */
+	mutex_lock(&serial_priv->urb_mutex);
+
+	if (serial_priv->opened_port) {
+		status = f81534_submit_read_urb(serial, GFP_NOIO);
+		if (status) {
+			mutex_unlock(&serial_priv->urb_mutex);
+			return status;
+		}
+	}
+
+	mutex_unlock(&serial_priv->urb_mutex);
+
+	for (i = 0; i < serial->num_ports; i++) {
+		port = serial->port[i];
+		if (!tty_port_initialized(&port->port))
+			continue;
+
+		status = f81534_submit_writer(port, GFP_NOIO);
+		if (status) {
+			dev_err(&port->dev, "%s: submit failed\n", __func__);
+			++error;
+		}
+	}
+
+	if (error)
+		return -EIO;
+
+	return 0;
+}
+
+static struct usb_serial_driver f81534_device = {
+	.driver = {
+		   .owner = THIS_MODULE,
+		   .name = "f81534",
+	},
+	.description =		DRIVER_DESC,
+	.id_table =		f81534_id_table,
+	.open =			f81534_open,
+	.close =		f81534_close,
+	.write =		f81534_write,
+	.tx_empty =		f81534_tx_empty,
+	.calc_num_ports =	f81534_calc_num_ports,
+	.probe =		f81534_probe,
+	.attach =		f81534_attach,
+	.port_probe =		f81534_port_probe,
+	.dtr_rts =		f81534_dtr_rts,
+	.process_read_urb =	f81534_process_read_urb,
+	.ioctl =		f81534_ioctl,
+	.tiocmget =		f81534_tiocmget,
+	.tiocmset =		f81534_tiocmset,
+	.write_bulk_callback =	f81534_write_usb_callback,
+	.set_termios =		f81534_set_termios,
+	.resume =		f81534_resume,
+};
+
+static struct usb_serial_driver *const serial_drivers[] = {
+	&f81534_device, NULL
+};
+
+module_usb_serial_driver(serial_drivers, f81534_id_table);
+
+MODULE_DEVICE_TABLE(usb, f81534_id_table);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Peter Hong <Peter_Hong@fintek.com.tw>");
+MODULE_AUTHOR("Tom Tsai <Tom_Tsai@fintek.com.tw>");
+MODULE_LICENSE("GPL");