cypress_m8.c

linux-2.6.15.6

/*
 * USB Cypress M8 driver
 *
 * 	Copyright (C) 2004
 * 	    Lonnie Mendez ([e-mail]) 
 *	Copyright (C) 2003,2004
 *	    Neil Whelchel ([e-mail])
 *
 * 	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.
 *
 * See Documentation/usb/usb-serial.txt for more information on using this driver
 *
 * See http://geocities.com/i0xox0i for information on this driver and the
 * earthmate usb device.
 *
 *  Lonnie Mendez <[e-mail]>
 *  4-29-2005
 *	Fixed problem where setting or retreiving the serial config would fail with
 * 	EPIPE.  Removed CRTS toggling so the driver behaves more like other usbserial
 * 	adapters.  Issued new interval of 1ms instead of the default 10ms.  As a
 * 	result, transfer speed has been substantially increased.  From avg. 850bps to
 * 	avg. 3300bps.  initial termios has also been modified.  Cleaned up code and
 * 	formatting issues so it is more readable.  Replaced the C++ style comments.
 *
 *  Lonnie Mendez <[e-mail]>
 *  12-15-2004
 *	Incorporated write buffering from pl2303 driver.  Fixed bug with line
 *	handling so both lines are raised in cypress_open. (was dropping rts)
 *      Various code cleanups made as well along with other misc bug fixes.
 *
 *  Lonnie Mendez <[e-mail]>
 *  04-10-2004
 *	Driver modified to support dynamic line settings.  Various improvments
 *      and features.
 *
 *  Neil Whelchel
 *  10-2003
 *	Driver first released.
 *
 */

/* Thanks to Neil Whelchel for writing the first cypress m8 implementation for linux. */
/* Thanks to cypress for providing references for the hid reports. */
/* Thanks to Jiang Zhang for providing links and for general help. */
/* Code originates and was built up from ftdi_sio, belkin, pl2303 and others. */


#include <linux/config.h>
#include <linux/kernel.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/moduleparam.h>
#include <linux/spinlock.h>
#include <linux/usb.h>
#include <linux/serial.h>
#include <linux/delay.h>
#include <asm/uaccess.h>

#include "usb-serial.h"
#include "cypress_m8.h"


#ifdef CONFIG_USB_SERIAL_DEBUG
	static int debug = 1;
#else
	static int debug;
#endif
static int stats;
static int interval;

/*
 * Version Information
 */
#define DRIVER_VERSION "v1.09"
#define DRIVER_AUTHOR "Lonnie Mendez <[e-mail]>, Neil Whelchel <[e-mail]>"
#define DRIVER_DESC "Cypress USB to Serial Driver"

/* write buffer size defines */
#define CYPRESS_BUF_SIZE	1024
#define CYPRESS_CLOSING_WAIT	(30*HZ)

static struct usb_device_id id_table_earthmate [] = {
	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
	{ }						/* Terminating entry */
};

static struct usb_device_id id_table_cyphidcomrs232 [] = {
	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
	{ }						/* Terminating entry */
};

static struct usb_device_id id_table_combined [] = {
	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
	{ }						/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, id_table_combined);

static struct usb_driver cypress_driver = {
	.name =		"cypress",
	.probe =	usb_serial_probe,
	.disconnect =	usb_serial_disconnect,
	.id_table =	id_table_combined,
};

struct cypress_private {
	spinlock_t lock;		   /* private lock */
	int chiptype;			   /* identifier of device, for quirks/etc */
	int bytes_in;			   /* used for statistics */
	int bytes_out;			   /* used for statistics */
	int cmd_count;			   /* used for statistics */
	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
	struct cypress_buf *buf;	   /* write buffer */
	int write_urb_in_use;		   /* write urb in use indicator */
	int termios_initialized;
	__u8 line_control;	   	   /* holds dtr / rts value */
	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
	__u8 current_config;	   	   /* stores the current configuration byte */
	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
	int baud_rate;			   /* stores current baud rate in integer form */
	int cbr_mask;			   /* stores current baud rate in masked form */
	int isthrottled;		   /* if throttled, discard reads */
	wait_queue_head_t delta_msr_wait;  /* used for TIOCMIWAIT */
	char prev_status, diff_status;	   /* used for TIOCMIWAIT */
	/* we pass a pointer to this as the arguement sent to cypress_set_termios old_termios */
	struct termios tmp_termios; 	   /* stores the old termios settings */
};

/* write buffer structure */
struct cypress_buf {
	unsigned int	buf_size;
	char		*buf_buf;
	char		*buf_get;
	char		*buf_put;
};

/* function prototypes for the Cypress USB to serial device */
static int  cypress_earthmate_startup	(struct usb_serial *serial);
static int  cypress_hidcom_startup	(struct usb_serial *serial);
static void cypress_shutdown		(struct usb_serial *serial);
static int  cypress_open		(struct usb_serial_port *port, struct file *filp);
static void cypress_close		(struct usb_serial_port *port, struct file *filp);
static int  cypress_write		(struct usb_serial_port *port, const unsigned char *buf, int count);
static void cypress_send		(struct usb_serial_port *port);
static int  cypress_write_room		(struct usb_serial_port *port);
static int  cypress_ioctl		(struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
static void cypress_set_termios		(struct usb_serial_port *port, struct termios * old);
static int  cypress_tiocmget		(struct usb_serial_port *port, struct file *file);
static int  cypress_tiocmset		(struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear);
static int  cypress_chars_in_buffer	(struct usb_serial_port *port);
static void cypress_throttle		(struct usb_serial_port *port);
static void cypress_unthrottle		(struct usb_serial_port *port);
static void cypress_read_int_callback	(struct urb *urb, struct pt_regs *regs);
static void cypress_write_int_callback	(struct urb *urb, struct pt_regs *regs);
/* baud helper functions */
static int	 mask_to_rate		(unsigned mask);
static unsigned  rate_to_mask		(int rate);
/* write buffer functions */
static struct cypress_buf *cypress_buf_alloc(unsigned int size);
static void 		  cypress_buf_free(struct cypress_buf *cb);
static void		  cypress_buf_clear(struct cypress_buf *cb);
static unsigned int	  cypress_buf_data_avail(struct cypress_buf *cb);
static unsigned int	  cypress_buf_space_avail(struct cypress_buf *cb);
static unsigned int	  cypress_buf_put(struct cypress_buf *cb, const char *buf, unsigned int count);
static unsigned int	  cypress_buf_get(struct cypress_buf *cb, char *buf, unsigned int count);


static struct usb_serial_driver cypress_earthmate_device = {
	.driver = {
		.owner =		THIS_MODULE,
		.name =			"earthmate",
	},
	.description =			"DeLorme Earthmate USB",
	.id_table =			id_table_earthmate,
	.num_interrupt_in = 		1,
	.num_interrupt_out =		1,
	.num_bulk_in =			NUM_DONT_CARE,
	.num_bulk_out =			NUM_DONT_CARE,
	.num_ports =			1,
	.attach =			cypress_earthmate_startup,
	.shutdown =			cypress_shutdown,
	.open =				cypress_open,
	.close =			cypress_close,
	.write =			cypress_write,
	.write_room =			cypress_write_room,
	.ioctl =			cypress_ioctl,
	.set_termios =			cypress_set_termios,
	.tiocmget =			cypress_tiocmget,
	.tiocmset =			cypress_tiocmset,
	.chars_in_buffer =		cypress_chars_in_buffer,
	.throttle =		 	cypress_throttle,
	.unthrottle =			cypress_unthrottle,
	.read_int_callback =		cypress_read_int_callback,
	.write_int_callback =		cypress_write_int_callback,
};

static struct usb_serial_driver cypress_hidcom_device = {
	.driver = {
		.owner =		THIS_MODULE,
		.name =			"cyphidcom",
	},
	.description =			"HID->COM RS232 Adapter",
	.id_table =			id_table_cyphidcomrs232,
	.num_interrupt_in =		1,
	.num_interrupt_out =		1,
	.num_bulk_in =			NUM_DONT_CARE,
	.num_bulk_out =			NUM_DONT_CARE,
	.num_ports =			1,
	.attach =			cypress_hidcom_startup,
	.shutdown =			cypress_shutdown,
	.open =				cypress_open,
	.close =			cypress_close,
	.write =			cypress_write,
	.write_room =			cypress_write_room,
	.ioctl =			cypress_ioctl,
	.set_termios =			cypress_set_termios,
	.tiocmget =			cypress_tiocmget,
	.tiocmset =			cypress_tiocmset,
	.chars_in_buffer =		cypress_chars_in_buffer,
	.throttle =			cypress_throttle,
	.unthrottle =			cypress_unthrottle,
	.read_int_callback =		cypress_read_int_callback,
	.write_int_callback =		cypress_write_int_callback,
};


/*****************************************************************************
 * Cypress serial helper functions
 *****************************************************************************/


/* This function can either set or retrieve the current serial line settings */
static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_mask, int data_bits, int stop_bits,
				   int parity_enable, int parity_type, int reset, int cypress_request_type)
{
	int new_baudrate = 0, retval = 0, tries = 0;
	struct cypress_private *priv;
	__u8 feature_buffer[8];
	unsigned long flags;

	dbg("%s", __FUNCTION__);
	
	priv = usb_get_serial_port_data(port);

	switch(cypress_request_type) {
		case CYPRESS_SET_CONFIG:

			/*
			 * The general purpose firmware for the Cypress M8 allows for a maximum speed
 			 * of 57600bps (I have no idea whether DeLorme chose to use the general purpose
			 * firmware or not), if you need to modify this speed setting for your own
			 * project please add your own chiptype and modify the code likewise.  The
			 * Cypress HID->COM device will work successfully up to 115200bps (but the
			 * actual throughput is around 3kBps).
			 */
			if (baud_mask != priv->cbr_mask) {
				dbg("%s - baud rate is changing", __FUNCTION__);
				if ( priv->chiptype == CT_EARTHMATE ) {
					/* 300 and 600 baud rates are supported under the generic firmware,
					 * but are not used with NMEA and SiRF protocols */
					
					if ( (baud_mask == B300) || (baud_mask == B600) ) {
						err("%s - failed setting baud rate, unsupported speed",
						    __FUNCTION__);
						new_baudrate = priv->baud_rate;
					} else if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
						err("%s - failed setting baud rate, unsupported speed",
						    __FUNCTION__);
						new_baudrate = priv->baud_rate;
					}
				} else if (priv->chiptype == CT_CYPHIDCOM) {
					if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
						err("%s - failed setting baud rate, unsupported speed",
						    __FUNCTION__);
						new_baudrate = priv->baud_rate;
					}
				} else if (priv->chiptype == CT_GENERIC) {
					if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
						err("%s - failed setting baud rate, unsupported speed",
						    __FUNCTION__);
						new_baudrate = priv->baud_rate;
					}
				} else {
					info("%s - please define your chiptype", __FUNCTION__);
					new_baudrate = priv->baud_rate;
				}
			} else {  /* baud rate not changing, keep the old */
				new_baudrate = priv->baud_rate;
			}
			dbg("%s - baud rate is being sent as %d", __FUNCTION__, new_baudrate);
			
			memset(feature_buffer, 0, 8);
			/* fill the feature_buffer with new configuration */
			*((u_int32_t *)feature_buffer) = new_baudrate;

			feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
			/* 1 bit gap */
			feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
			feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
			feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
			/* 1 bit gap */
			feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
				
			dbg("%s - device is being sent this feature report:", __FUNCTION__);
			dbg("%s - %02X - %02X - %02X - %02X - %02X", __FUNCTION__, feature_buffer[0], feature_buffer[1],
		            feature_buffer[2], feature_buffer[3], feature_buffer[4]);
			
			do {
			retval = usb_control_msg (port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
					  	  HID_REQ_SET_REPORT, USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
						  	  0x0300, 0, feature_buffer, 8, 500);

				if (tries++ >= 3)
					break;

				if (retval == EPIPE)
					usb_clear_halt(port->serial->dev, 0x00);
			} while (retval != 8 && retval != ENODEV);

			if (retval != 8)
				err("%s - failed sending serial line settings - %d", __FUNCTION__, retval);
			else {
				spin_lock_irqsave(&priv->lock, flags);
				priv->baud_rate = new_baudrate;
				priv->cbr_mask = baud_mask;
				priv->current_config = feature_buffer[4];
				spin_unlock_irqrestore(&priv->lock, flags);
			}
		break;
		case CYPRESS_GET_CONFIG:
			dbg("%s - retreiving serial line settings", __FUNCTION__);
			/* set initial values in feature buffer */
			memset(feature_buffer, 0, 8);

			do {
			retval = usb_control_msg (port->serial->dev, usb_rcvctrlpipe(port->serial->dev, 0),
						  HID_REQ_GET_REPORT, USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
							  0x0300, 0, feature_buffer, 8, 500);
				
				if (tries++ >= 3)
					break;

				if (retval == EPIPE)
					usb_clear_halt(port->serial->dev, 0x00);
			} while (retval != 5 && retval != ENODEV);

			if (retval != 5) {
				err("%s - failed to retreive serial line settings - %d", __FUNCTION__, retval);
				return retval;
			} else {
				spin_lock_irqsave(&priv->lock, flags);

				/* store the config in one byte, and later use bit masks to check values */
				priv->current_config = feature_buffer[4];
				priv->baud_rate = *((u_int32_t *)feature_buffer);
				
				if ( (priv->cbr_mask = rate_to_mask(priv->baud_rate)) == 0x40)
					dbg("%s - failed setting the baud mask (not defined)", __FUNCTION__);
				spin_unlock_irqrestore(&priv->lock, flags);
			}
	}
	spin_lock_irqsave(&priv->lock, flags);
	++priv->cmd_count;
	spin_unlock_irqrestore(&priv->lock, flags);

	return retval;
} /* cypress_serial_control */


/* given a baud mask, it will return integer baud on success */
static int mask_to_rate (unsigned mask)
{
	int rate;

	switch (mask) {
		case B0: rate = 0; break;
		case B300: rate = 300; break;
		case B600: rate = 600; break;
		case B1200: rate = 1200; break;
		case B2400: rate = 2400; break;
		case B4800: rate = 4800; break;
		case B9600: rate = 9600; break;
		case B19200: rate = 19200; break;
		case B38400: rate = 38400; break;
		case B57600: rate = 57600; break;
		case B115200: rate = 115200; break;
		default: rate = -1;
	}

	return rate;
}


static unsigned rate_to_mask (int rate)
{
	unsigned mask;

	switch (rate) {
		case 0: mask = B0; break;
		case 300: mask = B300; break;
		case 600: mask = B600; break;
		case 1200: mask = B1200; break;
		case 2400: mask = B2400; break;
		case 4800: mask = B4800; break;
		case 9600: mask = B9600; break;
		case 19200: mask = B19200; break;
		case 38400: mask = B38400; break;
		case 57600: mask = B57600; break;
		case 115200: mask = B115200; break;
		default: mask = 0x40;
	}

	return mask;
}
/*****************************************************************************
 * Cypress serial driver functions
 *****************************************************************************/


static int generic_startup (struct usb_serial *serial)
{
	struct cypress_private *priv;

	dbg("%s - port %d", __FUNCTION__, serial->port[0]->number);

	priv = kmalloc(sizeof (struct cypress_private), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	memset(priv, 0x00, sizeof (struct cypress_private));
	spin_lock_init(&priv->lock);
	priv->buf = cypress_buf_alloc(CYPRESS_BUF_SIZE);
	if (priv->buf == NULL) {
		kfree(priv);
		return -ENOMEM;
	}
	init_waitqueue_head(&priv->delta_msr_wait);
	
	usb_reset_configuration (serial->dev);
	
	interval = 1;
	priv->cmd_ctrl = 0;
	priv->line_control = 0;
	priv->termios_initialized = 0;
	priv->rx_flags = 0;
	priv->cbr_mask = B300;
	usb_set_serial_port_data(serial->port[0], priv);
	
	return 0;
}


static int cypress_earthmate_startup (struct usb_serial *serial)
{
	struct cypress_private *priv;

	dbg("%s", __FUNCTION__);

	if (generic_startup(serial)) {
		dbg("%s - Failed setting up port %d", __FUNCTION__,
				serial->port[0]->number);
		return 1;
	}

	priv = usb_get_serial_port_data(serial->port[0]);
	priv->chiptype = CT_EARTHMATE;

	return 0;
} /* cypress_earthmate_startup */


static int cypress_hidcom_startup (struct usb_serial *serial)
{
	struct cypress_private *priv;

	dbg("%s", __FUNCTION__);

	if (generic_startup(serial)) {
		dbg("%s - Failed setting up port %d", __FUNCTION__,
				serial->port[0]->number);
		return 1;
	}

	priv = usb_get_serial_port_data(serial->port[0]);
	priv->chiptype = CT_CYPHIDCOM;
	
	return 0;
} /* cypress_hidcom_startup */


static void cypress_shutdown (struct usb_serial *serial)
{
	struct cypress_private *priv;

	dbg ("%s - port %d", __FUNCTION__, serial->port[0]->number);

	/* all open ports are closed at this point */

	priv = usb_get_serial_port_data(serial->port[0]);

	if (priv) {
		cypress_buf_free(priv->buf);
		kfree(priv);
		usb_set_serial_port_data(serial->port[0], NULL);
	}
}


static int cypress_open (struct usb_serial_port *port, struct file *filp)
{
	struct cypress_private *priv = usb_get_serial_port_data(port);
	struct usb_serial *serial = port->serial;
	unsigned long flags;
	int result = 0;

	dbg("%s - port %d", __FUNCTION__, port->number);

	/* clear halts before open */