ftdi_sio.c

標準的linux下rs-232驅動代碼,是2.6內核的.

	{ USB_DEVICE(FTDI_VID, FTDI_PIEGROUP_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_TNC_X_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_USBX_707_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2101_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2102_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2103_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2104_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2106_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2201_1_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2201_2_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2202_1_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2202_2_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2203_1_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2203_2_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2401_1_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2401_2_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2401_3_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2401_4_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2402_1_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2402_2_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2402_3_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2402_4_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2403_1_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2403_2_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2403_3_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2403_4_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2801_1_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2801_2_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2801_3_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2801_4_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2801_5_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2801_6_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2801_7_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2801_8_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2802_1_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2802_2_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2802_3_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2802_4_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2802_5_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2802_6_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2802_7_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2802_8_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2803_1_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2803_2_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2803_3_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2803_4_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2803_5_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2803_6_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2803_7_PID) },
	{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2803_8_PID) },
	{ USB_DEVICE(IDTECH_VID, IDTECH_IDT1221U_PID) },
	{ USB_DEVICE(OCT_VID, OCT_US101_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_HE_TIRA1_PID),
		.driver_info = (kernel_ulong_t)&ftdi_HE_TIRA1_quirk },
	{ USB_DEVICE(FTDI_VID, FTDI_USB_UIRT_PID),
		.driver_info = (kernel_ulong_t)&ftdi_USB_UIRT_quirk },
	{ USB_DEVICE(FTDI_VID, PROTEGO_SPECIAL_1) },
	{ USB_DEVICE(FTDI_VID, PROTEGO_R2X0) },
	{ USB_DEVICE(FTDI_VID, PROTEGO_SPECIAL_3) },
	{ USB_DEVICE(FTDI_VID, PROTEGO_SPECIAL_4) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E808_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E809_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E80A_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E80B_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E80C_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E80D_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E80E_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E80F_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E888_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E889_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E88A_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E88B_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E88C_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E88D_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E88E_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GUDEADS_E88F_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_UO100_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_UM100_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_UR100_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_ALC8500_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_PYRAMID_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_FHZ1000PC_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_IBS_US485_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_IBS_PICPRO_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_IBS_PCMCIA_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_IBS_PK1_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_IBS_RS232MON_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_IBS_APP70_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_IBS_PEDO_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_IBS_PROD_PID) },
	/*
	 * Due to many user requests for multiple ELV devices we enable
	 * them by default.
	 */
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_CLI7000_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_PPS7330_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_TFM100_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_UDF77_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_UIO88_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_UAD8_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_UDA7_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_USI2_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_T1100_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_PCD200_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_ULA200_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_CSI8_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_EM1000DL_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_PCK100_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_RFP500_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_FS20SIG_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_WS300PC_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_FHZ1300PC_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELV_WS500_PID) },
	{ USB_DEVICE(FTDI_VID, LINX_SDMUSBQSS_PID) },
	{ USB_DEVICE(FTDI_VID, LINX_MASTERDEVEL2_PID) },
	{ USB_DEVICE(FTDI_VID, LINX_FUTURE_0_PID) },
	{ USB_DEVICE(FTDI_VID, LINX_FUTURE_1_PID) },
	{ USB_DEVICE(FTDI_VID, LINX_FUTURE_2_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_CCSICDU20_0_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_CCSICDU40_1_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_CCSMACHX_2_PID) },
	{ USB_DEVICE(FTDI_VID, INSIDE_ACCESSO) },
	{ USB_DEVICE(INTREPID_VID, INTREPID_VALUECAN_PID) },
	{ USB_DEVICE(INTREPID_VID, INTREPID_NEOVI_PID) },
	{ USB_DEVICE(FALCOM_VID, FALCOM_TWIST_PID) },
	{ USB_DEVICE(FALCOM_VID, FALCOM_SAMBA_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_SUUNTO_SPORTS_PID) },
	{ USB_DEVICE(TTI_VID, TTI_QL355P_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_RM_CANVIEW_PID) },
	{ USB_DEVICE(BANDB_VID, BANDB_USOTL4_PID) },
	{ USB_DEVICE(BANDB_VID, BANDB_USTL4_PID) },
	{ USB_DEVICE(BANDB_VID, BANDB_USO9ML2_PID) },
	{ USB_DEVICE(FTDI_VID, EVER_ECO_PRO_CDS) },
	{ USB_DEVICE(FTDI_VID, FTDI_4N_GALAXY_DE_1_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_4N_GALAXY_DE_2_PID) },
	{ USB_DEVICE(FTDI_VID, XSENS_CONVERTER_0_PID) },
	{ USB_DEVICE(FTDI_VID, XSENS_CONVERTER_1_PID) },
	{ USB_DEVICE(FTDI_VID, XSENS_CONVERTER_2_PID) },
	{ USB_DEVICE(FTDI_VID, XSENS_CONVERTER_3_PID) },
	{ USB_DEVICE(FTDI_VID, XSENS_CONVERTER_4_PID) },
	{ USB_DEVICE(FTDI_VID, XSENS_CONVERTER_5_PID) },
	{ USB_DEVICE(FTDI_VID, XSENS_CONVERTER_6_PID) },
	{ USB_DEVICE(FTDI_VID, XSENS_CONVERTER_7_PID) },
	{ USB_DEVICE(MOBILITY_VID, MOBILITY_USB_SERIAL_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ACTIVE_ROBOTS_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_MHAM_KW_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_MHAM_YS_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_MHAM_Y6_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_MHAM_Y8_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_MHAM_IC_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_MHAM_DB9_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_MHAM_RS232_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_MHAM_Y9_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_TERATRONIK_VCP_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_TERATRONIK_D2XX_PID) },
	{ USB_DEVICE(EVOLUTION_VID, EVOLUTION_ER1_PID) },
	{ USB_DEVICE(EVOLUTION_VID, EVO_HYBRID_PID) },
	{ USB_DEVICE(EVOLUTION_VID, EVO_RCM4_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ARTEMIS_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ATIK_ATK16_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ATIK_ATK16C_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ATIK_ATK16HR_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ATIK_ATK16HRC_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ATIK_ATK16IC_PID) },
	{ USB_DEVICE(KOBIL_VID, KOBIL_CONV_B1_PID) },
	{ USB_DEVICE(KOBIL_VID, KOBIL_CONV_KAAN_PID) },
	{ USB_DEVICE(POSIFLEX_VID, POSIFLEX_PP7000_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_TTUSB_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ECLO_COM_1WIRE_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_WESTREX_MODEL_777_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_WESTREX_MODEL_8900F_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_PCDJ_DAC2_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_RRCIRKITS_LOCOBUFFER_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ASK_RDR400_PID) },
	{ USB_DEVICE(ICOM_ID1_VID, ICOM_ID1_PID) },
	{ USB_DEVICE(PAPOUCH_VID, PAPOUCH_TMU_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ACG_HFDUAL_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_YEI_SERVOCENTER31_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_THORLABS_PID) },
	{ USB_DEVICE(TESTO_VID, TESTO_USB_INTERFACE_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_GAMMA_SCOUT_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_TACTRIX_OPENPORT_13M_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_TACTRIX_OPENPORT_13S_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_TACTRIX_OPENPORT_13U_PID) },
	{ USB_DEVICE(ELEKTOR_VID, ELEKTOR_FT323R_PID) },
	{ USB_DEVICE(TELLDUS_VID, TELLDUS_TELLSTICK_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_MAXSTREAM_PID) },
	{ USB_DEVICE(TML_VID, TML_USB_SERIAL_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_ELSTER_UNICOM_PID) },
	{ USB_DEVICE(OLIMEX_VID, OLIMEX_ARM_USB_OCD_PID),
		.driver_info = (kernel_ulong_t)&ftdi_olimex_quirk },
	{ },					/* Optional parameter entry */
	{ }					/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, id_table_combined);

static struct usb_driver ftdi_driver = {
	.name =		"ftdi_sio",
	.probe =	usb_serial_probe,
	.disconnect =	usb_serial_disconnect,
	.id_table =	id_table_combined,
	.no_dynamic_id =	1,
};

static const char *ftdi_chip_name[] = {
	[SIO] = "SIO",	/* the serial part of FT8U100AX */
	[FT8U232AM] = "FT8U232AM",
	[FT232BM] = "FT232BM",
	[FT2232C] = "FT2232C",
	[FT232RL] = "FT232RL",
	[FT2232H] = "FT2232H",
	[FT4232H] = "FT4232H"
};


/* Constants for read urb and write urb */
#define BUFSZ 512
#define PKTSZ 64

/* rx_flags */
#define THROTTLED		0x01
#define ACTUALLY_THROTTLED	0x02

/* Used for TIOCMIWAIT */
#define FTDI_STATUS_B0_MASK	(FTDI_RS0_CTS | FTDI_RS0_DSR | FTDI_RS0_RI | FTDI_RS0_RLSD)
#define FTDI_STATUS_B1_MASK	(FTDI_RS_BI)
/* End TIOCMIWAIT */

#define FTDI_IMPL_ASYNC_FLAGS = ( ASYNC_SPD_HI | ASYNC_SPD_VHI \
 ASYNC_SPD_CUST | ASYNC_SPD_SHI | ASYNC_SPD_WARP )

/* function prototypes for a FTDI serial converter */
static int  ftdi_sio_probe	(struct usb_serial *serial, const struct usb_device_id *id);
static void ftdi_shutdown		(struct usb_serial *serial);
static int  ftdi_sio_port_probe	(struct usb_serial_port *port);
static int  ftdi_sio_port_remove	(struct usb_serial_port *port);
static int  ftdi_open			(struct usb_serial_port *port, struct file *filp);
static void ftdi_close			(struct usb_serial_port *port, struct file *filp);
static int  ftdi_write			(struct usb_serial_port *port, const unsigned char *buf, int count);
static int  ftdi_write_room		(struct usb_serial_port *port);
static int  ftdi_chars_in_buffer	(struct usb_serial_port *port);
static void ftdi_write_bulk_callback	(struct urb *urb);
static void ftdi_read_bulk_callback	(struct urb *urb);
static void ftdi_process_read		(struct work_struct *work);
static void ftdi_set_termios		(struct usb_serial_port *port, struct ktermios * old);
static int  ftdi_tiocmget               (struct usb_serial_port *port, struct file *file);
static int  ftdi_tiocmset		(struct usb_serial_port *port, struct file * file, unsigned int set, unsigned int clear);
static int  ftdi_ioctl			(struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
static void ftdi_break_ctl		(struct usb_serial_port *port, int break_state );
static void ftdi_throttle		(struct usb_serial_port *port);
static void ftdi_unthrottle		(struct usb_serial_port *port);

static unsigned short int ftdi_232am_baud_base_to_divisor (int baud, int base);
static unsigned short int ftdi_232am_baud_to_divisor (int baud);
static __u32 ftdi_232bm_baud_base_to_divisor (int baud, int base);
static __u32 ftdi_232bm_baud_to_divisor (int baud);
static __u32 ftdi_2232h_baud_base_to_divisor (int baud, int base);
static __u32 ftdi_2232h_baud_to_divisor (int baud);

static struct usb_serial_driver ftdi_sio_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"ftdi_sio",
	},
	.description =		"FTDI USB Serial Device",
	.usb_driver = 		&ftdi_driver ,
	.id_table =		id_table_combined,
	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.probe =		ftdi_sio_probe,
	.port_probe =		ftdi_sio_port_probe,
	.port_remove =		ftdi_sio_port_remove,
	.open =			ftdi_open,
	.close =		ftdi_close,
	.throttle =		ftdi_throttle,
	.unthrottle =		ftdi_unthrottle,
	.write =		ftdi_write,
	.write_room =		ftdi_write_room,
	.chars_in_buffer =	ftdi_chars_in_buffer,
	.read_bulk_callback =	ftdi_read_bulk_callback,
	.write_bulk_callback =	ftdi_write_bulk_callback,
	.tiocmget =             ftdi_tiocmget,
	.tiocmset =             ftdi_tiocmset,
	.ioctl =		ftdi_ioctl,
	.set_termios =		ftdi_set_termios,
	.break_ctl =		ftdi_break_ctl,
	.shutdown =		ftdi_shutdown,
};


#define WDR_TIMEOUT 5000 /* default urb timeout */
#define WDR_SHORT_TIMEOUT 1000	/* shorter urb timeout */

/* High and low are for DTR, RTS etc etc */
#define HIGH 1
#define LOW 0

/* number of outstanding urbs to prevent userspace DoS from happening */
#define URB_UPPER_LIMIT	42

/*
 * ***************************************************************************
 * Utility functions
 * ***************************************************************************
 */

static unsigned short int ftdi_232am_baud_base_to_divisor(int baud, int base)
{
	unsigned short int divisor;
	int divisor3 = base / 2 / baud; // divisor shifted 3 bits to the left
	if ((divisor3 & 0x7) == 7) divisor3 ++; // round x.7/8 up to x+1
	divisor = divisor3 >> 3;
	divisor3 &= 0x7;
	if (divisor3 == 1) divisor |= 0xc000; else // 0.125
	if (divisor3 >= 4) divisor |= 0x4000; else // 0.5
	if (divisor3 != 0) divisor |= 0x8000;      // 0.25
	if (divisor == 1) divisor = 0;	/* special case for maximum baud rate */
	return divisor;
}

static unsigned short int ftdi_232am_baud_to_divisor(int baud)
{
	 return(ftdi_232am_baud_base_to_divisor(baud, 48000000));
}

static __u32 ftdi_232bm_baud_base_to_divisor(int baud, int base)
{
	static const unsigned char divfrac[8] = { 0, 3, 2, 4, 1, 5, 6, 7 };
	__u32 divisor;
	int divisor3 = base / 2 / baud; // divisor shifted 3 bits to the left
	divisor = divisor3 >> 3;
	divisor |= (__u32)divfrac[divisor3 & 0x7] << 14;
	/* Deal with special cases for highest baud rates. */
	if (divisor == 1) divisor = 0; else	// 1.0
	if (divisor == 0x4001) divisor = 1;	// 1.5
	return divisor;
}

static __u32 ftdi_232bm_baud_to_divisor(int baud)
{
	 return(ftdi_232bm_baud_base_to_divisor(baud, 48000000));
}

static __u32 ftdi_2232h_baud_base_to_divisor(int baud, int base)
{
	static const unsigned char divfrac[8] = { 0, 3, 2, 4, 1, 5, 6, 7 };
	__u32 divisor;
	int divisor3 = (base / 10 / baud) * 8; // hi-speed baud rate is 10-bit sampling instead of 16-bit
	divisor = divisor3 >> 3;
	divisor |= (__u32)divfrac[divisor3 & 0x7] << 14;
	/* Deal with special cases for highest baud rates. */
	if (divisor == 1) divisor = 0; else	// 1.0
	if (divisor == 0x4001) divisor = 1;	// 1.5
	/* Set this bit to turn off a divide by 2.5 on baud rate generator */
	/* This enables baud rates up to 12Mbaud but cannot reach below 1200 baud with this bit set */
	divisor |= 0x00020000;
	return divisor;
}

static __u32 ftdi_2232h_baud_to_divisor(int baud)
{
	 return(ftdi_2232h_baud_base_to_divisor(baud, 120000000));
}

#define set_mctrl(port, set)		update_mctrl((port), (set), 0)
#define clear_mctrl(port, clear)	update_mctrl((port), 0, (clear))

static int update_mctrl(struct usb_serial_port *port, unsigned int set, unsigned int clear)
{
	struct ftdi_private *priv = usb_get_serial_port_data(port);
	char *buf;
	unsigned urb_value;
	int rv;

	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
		dbg("%s - DTR|RTS not being set|cleared", __FUNCTION__);
		return 0;	/* no change */
	}

	buf = kmalloc(1, GFP_NOIO);
	if (!buf) {
		return -ENOMEM;
	}