path: root/drivers/usb/serial/quatech2.c

/*
 * usb-serial driver for Quatech USB 2 devices
 *
 * Copyright (C) 2012 Bill Pemberton (wfp5p@virginia.edu)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 *
 *  These devices all have only 1 bulk in and 1 bulk out that is shared
 *  for all serial ports.
 *
 */

#include <asm/unaligned.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/serial.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/serial_reg.h>
#include <linux/uaccess.h>

/* default urb timeout for usb operations */
#define QT2_USB_TIMEOUT USB_CTRL_SET_TIMEOUT

#define QT_OPEN_CLOSE_CHANNEL       0xca
#define QT_SET_GET_DEVICE           0xc2
#define QT_SET_GET_REGISTER         0xc0
#define QT_GET_SET_PREBUF_TRIG_LVL  0xcc
#define QT_SET_ATF                  0xcd
#define QT_TRANSFER_IN              0xc0
#define QT_HW_FLOW_CONTROL_MASK     0xc5
#define QT_SW_FLOW_CONTROL_MASK     0xc6
#define QT2_BREAK_CONTROL	    0xc8
#define QT2_GET_SET_UART            0xc1
#define QT2_FLUSH_DEVICE	    0xc4
#define QT2_GET_SET_QMCR            0xe1
#define QT2_QMCR_RS232              0x40
#define QT2_QMCR_RS422              0x10

#define  SERIAL_CRTSCTS ((UART_MCR_RTS << 8) | UART_MSR_CTS)

#define  SERIAL_EVEN_PARITY         (UART_LCR_PARITY | UART_LCR_EPAR)

/* status bytes for the device */
#define QT2_CONTROL_BYTE    0x1b
#define QT2_LINE_STATUS     0x00  /* following 1 byte is line status */
#define QT2_MODEM_STATUS    0x01  /* following 1 byte is modem status */
#define QT2_XMIT_HOLD       0x02  /* following 2 bytes are ?? */
#define QT2_CHANGE_PORT     0x03  /* following 1 byte is port to change to */
#define QT2_REC_FLUSH       0x04  /* no following info */
#define QT2_XMIT_FLUSH      0x05  /* no following info */
#define QT2_CONTROL_ESCAPE  0xff  /* pass through previous 2 control bytes */

#define  MAX_BAUD_RATE              921600
#define  DEFAULT_BAUD_RATE          9600

#define QT2_WRITE_BUFFER_SIZE   512  /* size of write buffer */
#define QT2_WRITE_CONTROL_SIZE  5    /* control bytes used for a write */

#define DRIVER_DESC "Quatech 2nd gen USB to Serial Driver"

#define	USB_VENDOR_ID_QUATECH	0x061d
#define QUATECH_SSU2_100	0xC120	/* RS232 single port */
#define QUATECH_DSU2_100	0xC140	/* RS232 dual port */
#define QUATECH_DSU2_400	0xC150	/* RS232/422/485 dual port */
#define QUATECH_QSU2_100	0xC160	/* RS232 four port */
#define QUATECH_QSU2_400	0xC170	/* RS232/422/485 four port */
#define QUATECH_ESU2_100	0xC1A0	/* RS232 eight port */
#define QUATECH_ESU2_400	0xC180	/* RS232/422/485 eight port */

struct qt2_device_detail {
	int product_id;
	int num_ports;
};

#define QT_DETAILS(prod, ports)	\
	.product_id = (prod),   \
	.num_ports = (ports)

static const struct qt2_device_detail qt2_device_details[] = {
	{QT_DETAILS(QUATECH_SSU2_100, 1)},
	{QT_DETAILS(QUATECH_DSU2_400, 2)},
	{QT_DETAILS(QUATECH_DSU2_100, 2)},
	{QT_DETAILS(QUATECH_QSU2_400, 4)},
	{QT_DETAILS(QUATECH_QSU2_100, 4)},
	{QT_DETAILS(QUATECH_ESU2_400, 8)},
	{QT_DETAILS(QUATECH_ESU2_100, 8)},
	{QT_DETAILS(0, 0)}	/* Terminating entry */
};

static const struct usb_device_id id_table[] = {
	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU2_100)},
	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_100)},
	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_400)},
	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_100)},
	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_400)},
	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_100)},
	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_400)},
	{}			/* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, id_table);

struct qt2_serial_private {
	unsigned char current_port;  /* current port for incoming data */

	struct urb	*read_urb;   /* shared among all ports */
	char		read_buffer[512];
};

struct qt2_port_private {
	bool is_open;
	u8   device_port;

	spinlock_t urb_lock;
	bool       urb_in_use;
	struct urb *write_urb;
	char       write_buffer[QT2_WRITE_BUFFER_SIZE];

	spinlock_t  lock;
	u8          shadowLSR;
	u8          shadowMSR;

	wait_queue_head_t   delta_msr_wait; /* Used for TIOCMIWAIT */
	struct async_icount icount;

	struct usb_serial_port *port;
};

static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch);
static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch);
static void qt2_write_bulk_callback(struct urb *urb);
static void qt2_read_bulk_callback(struct urb *urb);

static void qt2_release(struct usb_serial *serial)
{
	struct qt2_serial_private *serial_priv;

	serial_priv = usb_get_serial_data(serial);

	usb_free_urb(serial_priv->read_urb);
	kfree(serial_priv);
}

static inline int calc_baud_divisor(int baudrate)
{
	int divisor, rem;

	divisor = MAX_BAUD_RATE / baudrate;
	rem = MAX_BAUD_RATE </