cypress_m8.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * USB Cypress M8 driver
   4 *
   5 * 	Copyright (C) 2004
   6 * 	    Lonnie Mendez (dignome@gmail.com)
   7 *	Copyright (C) 2003,2004
   8 *	    Neil Whelchel (koyama@firstlight.net)
   9 *
  10 * See Documentation/usb/usb-serial.rst for more information on using this
  11 * driver
  12 *
  13 * See http://geocities.com/i0xox0i for information on this driver and the
  14 * earthmate usb device.
  15 */
  16
  17/* Thanks to Neil Whelchel for writing the first cypress m8 implementation
  18   for linux. */
  19/* Thanks to cypress for providing references for the hid reports. */
  20/* Thanks to Jiang Zhang for providing links and for general help. */
  21/* Code originates and was built up from ftdi_sio, belkin, pl2303 and others.*/
  22
  23
  24#include <linux/kernel.h>
  25#include <linux/errno.h>
  26#include <linux/slab.h>
  27#include <linux/tty.h>
  28#include <linux/tty_driver.h>
  29#include <linux/tty_flip.h>
  30#include <linux/module.h>
  31#include <linux/moduleparam.h>
  32#include <linux/spinlock.h>
  33#include <linux/usb.h>
  34#include <linux/usb/serial.h>
  35#include <linux/serial.h>
  36#include <linux/kfifo.h>
  37#include <linux/delay.h>
  38#include <linux/uaccess.h>
  39#include <linux/unaligned.h>
  40
  41#include "cypress_m8.h"
  42
  43
  44static bool stats;
  45static int interval;
  46static bool unstable_bauds;
  47
  48#define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
  49#define DRIVER_DESC "Cypress USB to Serial Driver"
  50
  51/* write buffer size defines */
  52#define CYPRESS_BUF_SIZE	1024
  53
  54static const struct usb_device_id id_table_earthmate[] = {
  55	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
  56	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
  57	{ }						/* Terminating entry */
  58};
  59
  60static const struct usb_device_id id_table_cyphidcomrs232[] = {
  61	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
  62	{ USB_DEVICE(VENDOR_ID_SAI, PRODUCT_ID_CYPHIDCOM) },
  63	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
  64	{ USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
  65	{ }						/* Terminating entry */
  66};
  67
  68static const struct usb_device_id id_table_nokiaca42v2[] = {
  69	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
  70	{ }						/* Terminating entry */
  71};
  72
  73static const struct usb_device_id id_table_combined[] = {
  74	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
  75	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
  76	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
  77	{ USB_DEVICE(VENDOR_ID_SAI, PRODUCT_ID_CYPHIDCOM) },
  78	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
  79	{ USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
  80	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
  81	{ }						/* Terminating entry */
  82};
  83
  84MODULE_DEVICE_TABLE(usb, id_table_combined);
  85
  86enum packet_format {
  87	packet_format_1,  /* b0:status, b1:payload count */
  88	packet_format_2   /* b0[7:3]:status, b0[2:0]:payload count */
  89};
  90
  91struct cypress_private {
  92	spinlock_t lock;		   /* private lock */
  93	int chiptype;			   /* identifier of device, for quirks/etc */
  94	int bytes_in;			   /* used for statistics */
  95	int bytes_out;			   /* used for statistics */
  96	int cmd_count;			   /* used for statistics */
  97	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
  98	struct kfifo write_fifo;	   /* write fifo */
  99	int write_urb_in_use;		   /* write urb in use indicator */
 100	int write_urb_interval;            /* interval to use for write urb */
 101	int read_urb_interval;             /* interval to use for read urb */
 102	int comm_is_ok;                    /* true if communication is (still) ok */
 103	__u8 line_control;	   	   /* holds dtr / rts value */
 104	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
 105	__u8 current_config;	   	   /* stores the current configuration byte */
 106	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
 107	enum packet_format pkt_fmt;	   /* format to use for packet send / receive */
 108	int get_cfg_unsafe;		   /* If true, the CYPRESS_GET_CONFIG is unsafe */
 109	int baud_rate;			   /* stores current baud rate in
 110					      integer form */
 111	char prev_status;		   /* used for TIOCMIWAIT */
 112};
 113
 114/* function prototypes for the Cypress USB to serial device */
 115static int  cypress_earthmate_port_probe(struct usb_serial_port *port);
 116static int  cypress_hidcom_port_probe(struct usb_serial_port *port);
 117static int  cypress_ca42v2_port_probe(struct usb_serial_port *port);
 118static void cypress_port_remove(struct usb_serial_port *port);
 119static int  cypress_open(struct tty_struct *tty, struct usb_serial_port *port);
 120static void cypress_close(struct usb_serial_port *port);
 121static void cypress_dtr_rts(struct usb_serial_port *port, int on);
 122static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
 123			const unsigned char *buf, int count);
 124static void cypress_send(struct usb_serial_port *port);
 125static unsigned int cypress_write_room(struct tty_struct *tty);
 126static void cypress_earthmate_init_termios(struct tty_struct *tty);
 127static void cypress_set_termios(struct tty_struct *tty,
 128				struct usb_serial_port *port,
 129				const struct ktermios *old_termios);
 130static int  cypress_tiocmget(struct tty_struct *tty);
 131static int  cypress_tiocmset(struct tty_struct *tty,
 132			unsigned int set, unsigned int clear);
 133static unsigned int cypress_chars_in_buffer(struct tty_struct *tty);
 134static void cypress_throttle(struct tty_struct *tty);
 135static void cypress_unthrottle(struct tty_struct *tty);
 136static void cypress_set_dead(struct usb_serial_port *port);
 137static void cypress_read_int_callback(struct urb *urb);
 138static void cypress_write_int_callback(struct urb *urb);
 139
 140static struct usb_serial_driver cypress_earthmate_device = {
 141	.driver = {
 142		.name =			"earthmate",
 143	},
 144	.description =			"DeLorme Earthmate USB",
 145	.id_table =			id_table_earthmate,
 146	.num_ports =			1,
 147	.port_probe =			cypress_earthmate_port_probe,
 148	.port_remove =			cypress_port_remove,
 149	.open =				cypress_open,
 150	.close =			cypress_close,
 151	.dtr_rts =			cypress_dtr_rts,
 152	.write =			cypress_write,
 153	.write_room =			cypress_write_room,
 154	.init_termios =			cypress_earthmate_init_termios,
 155	.set_termios =			cypress_set_termios,
 156	.tiocmget =			cypress_tiocmget,
 157	.tiocmset =			cypress_tiocmset,
 158	.tiocmiwait =			usb_serial_generic_tiocmiwait,
 159	.chars_in_buffer =		cypress_chars_in_buffer,
 160	.throttle =		 	cypress_throttle,
 161	.unthrottle =			cypress_unthrottle,
 162	.read_int_callback =		cypress_read_int_callback,
 163	.write_int_callback =		cypress_write_int_callback,
 164};
 165
 166static struct usb_serial_driver cypress_hidcom_device = {
 167	.driver = {
 168		.name =			"cyphidcom",
 169	},
 170	.description =			"HID->COM RS232 Adapter",
 171	.id_table =			id_table_cyphidcomrs232,
 172	.num_ports =			1,
 173	.port_probe =			cypress_hidcom_port_probe,
 174	.port_remove =			cypress_port_remove,
 175	.open =				cypress_open,
 176	.close =			cypress_close,
 177	.dtr_rts =			cypress_dtr_rts,
 178	.write =			cypress_write,
 179	.write_room =			cypress_write_room,
 180	.set_termios =			cypress_set_termios,
 181	.tiocmget =			cypress_tiocmget,
 182	.tiocmset =			cypress_tiocmset,
 183	.tiocmiwait =			usb_serial_generic_tiocmiwait,
 184	.chars_in_buffer =		cypress_chars_in_buffer,
 185	.throttle =			cypress_throttle,
 186	.unthrottle =			cypress_unthrottle,
 187	.read_int_callback =		cypress_read_int_callback,
 188	.write_int_callback =		cypress_write_int_callback,
 189};
 190
 191static struct usb_serial_driver cypress_ca42v2_device = {
 192	.driver = {
 193		.name =			"nokiaca42v2",
 194	},
 195	.description =			"Nokia CA-42 V2 Adapter",
 196	.id_table =			id_table_nokiaca42v2,
 197	.num_ports =			1,
 198	.port_probe =			cypress_ca42v2_port_probe,
 199	.port_remove =			cypress_port_remove,
 200	.open =				cypress_open,
 201	.close =			cypress_close,
 202	.dtr_rts =			cypress_dtr_rts,
 203	.write =			cypress_write,
 204	.write_room =			cypress_write_room,
 205	.set_termios =			cypress_set_termios,
 206	.tiocmget =			cypress_tiocmget,
 207	.tiocmset =			cypress_tiocmset,
 208	.tiocmiwait =			usb_serial_generic_tiocmiwait,
 209	.chars_in_buffer =		cypress_chars_in_buffer,
 210	.throttle =			cypress_throttle,
 211	.unthrottle =			cypress_unthrottle,
 212	.read_int_callback =		cypress_read_int_callback,
 213	.write_int_callback =		cypress_write_int_callback,
 214};
 215
 216static struct usb_serial_driver * const serial_drivers[] = {
 217	&cypress_earthmate_device, &cypress_hidcom_device,
 218	&cypress_ca42v2_device, NULL
 219};
 220
 221/*****************************************************************************
 222 * Cypress serial helper functions
 223 *****************************************************************************/
 224
 225/* FRWD Dongle hidcom needs to skip reset and speed checks */
 226static inline bool is_frwd(struct usb_device *dev)
 227{
 228	return ((le16_to_cpu(dev->descriptor.idVendor) == VENDOR_ID_FRWD) &&
 229		(le16_to_cpu(dev->descriptor.idProduct) == PRODUCT_ID_CYPHIDCOM_FRWD));
 230}
 231
 232static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
 233{
 234	struct cypress_private *priv;
 235	priv = usb_get_serial_port_data(port);
 236
 237	if (unstable_bauds)
 238		return new_rate;
 239
 240	/* FRWD Dongle uses 115200 bps */
 241	if (is_frwd(port->serial->dev))
 242		return new_rate;
 243
 244	/*
 245	 * The general purpose firmware for the Cypress M8 allows for
 246	 * a maximum speed of 57600bps (I have no idea whether DeLorme
 247	 * chose to use the general purpose firmware or not), if you
 248	 * need to modify this speed setting for your own project
 249	 * please add your own chiptype and modify the code likewise.
 250	 * The Cypress HID->COM device will work successfully up to
 251	 * 115200bps (but the actual throughput is around 3kBps).
 252	 */
 253	if (port->serial->dev->speed == USB_SPEED_LOW) {
 254		/*
 255		 * Mike Isely <isely@pobox.com> 2-Feb-2008: The
 256		 * Cypress app note that describes this mechanism
 257		 * states that the low-speed part can't handle more
 258		 * than 800 bytes/sec, in which case 4800 baud is the
 259		 * safest speed for a part like that.
 260		 */
 261		if (new_rate > 4800) {
 262			dev_dbg(&port->dev,
 263				"%s - failed setting baud rate, device incapable speed %d\n",
 264				__func__, new_rate);
 265			return -1;
 266		}
 267	}
 268	switch (priv->chiptype) {
 269	case CT_EARTHMATE:
 270		if (new_rate <= 600) {
 271			/* 300 and 600 baud rates are supported under
 272			 * the generic firmware, but are not used with
 273			 * NMEA and SiRF protocols */
 274			dev_dbg(&port->dev,
 275				"%s - failed setting baud rate, unsupported speed of %d on Earthmate GPS\n",
 276				__func__, new_rate);
 277			return -1;
 278		}
 279		break;
 280	default:
 281		break;
 282	}
 283	return new_rate;
 284}
 285
 286
 287/* This function can either set or retrieve the current serial line settings */
 288static int cypress_serial_control(struct tty_struct *tty,
 289	struct usb_serial_port *port, speed_t baud_rate, int data_bits,
 290	int stop_bits, int parity_enable, int parity_type, int reset,
 291	int cypress_request_type)
 292{
 293	int new_baudrate = 0, retval = 0, tries = 0;
 294	struct cypress_private *priv;
 295	struct device *dev = &port->dev;
 296	u8 *feature_buffer;
 297	const unsigned int feature_len = 5;
 298	unsigned long flags;
 299
 300	priv = usb_get_serial_port_data(port);
 301
 302	if (!priv->comm_is_ok)
 303		return -ENODEV;
 304
 305	feature_buffer = kcalloc(feature_len, sizeof(u8), GFP_KERNEL);
 306	if (!feature_buffer)
 307		return -ENOMEM;
 308
 309	switch (cypress_request_type) {
 310	case CYPRESS_SET_CONFIG:
 311		/* 0 means 'Hang up' so doesn't change the true bit rate */
 312		new_baudrate = priv->baud_rate;
 313		if (baud_rate && baud_rate != priv->baud_rate) {
 314			dev_dbg(dev, "%s - baud rate is changing\n", __func__);
 315			retval = analyze_baud_rate(port, baud_rate);
 316			if (retval >= 0) {
 317				new_baudrate = retval;
 318				dev_dbg(dev, "%s - New baud rate set to %d\n",
 319					__func__, new_baudrate);
 320			}
 321		}
 322		dev_dbg(dev, "%s - baud rate is being sent as %d\n", __func__,
 323			new_baudrate);
 324
 325		/* fill the feature_buffer with new configuration */
 326		put_unaligned_le32(new_baudrate, feature_buffer);
 327		feature_buffer[4] |= data_bits - 5;   /* assign data bits in 2 bit space ( max 3 ) */
 328		/* 1 bit gap */
 329		feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
 330		feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
 331		feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
 332		/* 1 bit gap */
 333		feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
 334
 335		dev_dbg(dev, "%s - device is being sent this feature report:\n", __func__);
 336		dev_dbg(dev, "%s - %02X - %02X - %02X - %02X - %02X\n", __func__,
 337			feature_buffer[0], feature_buffer[1],
 338			feature_buffer[2], feature_buffer[3],
 339			feature_buffer[4]);
 340
 341		do {
 342			retval = usb_control_msg(port->serial->dev,
 343					usb_sndctrlpipe(port->serial->dev, 0),
 344					HID_REQ_SET_REPORT,
 345					USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
 346					0x0300, 0, feature_buffer,
 347					feature_len, 500);
 348
 349			if (tries++ >= 3)
 350				break;
 351
 352		} while (retval != feature_len &&
 353			 retval != -ENODEV);
 354
 355		if (retval != feature_len) {
 356			dev_err(dev, "%s - failed sending serial line settings - %d\n",
 357				__func__, retval);
 358			cypress_set_dead(port);
 359		} else {
 360			spin_lock_irqsave(&priv->lock, flags);
 361			priv->baud_rate = new_baudrate;
 362			priv->current_config = feature_buffer[4];
 363			spin_unlock_irqrestore(&priv->lock, flags);
 364			/* If we asked for a speed change encode it */
 365			if (baud_rate)
 366				tty_encode_baud_rate(tty,
 367					new_baudrate, new_baudrate);
 368		}
 369	break;
 370	case CYPRESS_GET_CONFIG:
 371		if (priv->get_cfg_unsafe) {
 372			/* Not implemented for this device,
 373			   and if we try to do it we're likely
 374			   to crash the hardware. */
 375			retval = -ENOTTY;
 376			goto out;
 377		}
 378		dev_dbg(dev, "%s - retrieving serial line settings\n", __func__);
 379		do {
 380			retval = usb_control_msg(port->serial->dev,
 381					usb_rcvctrlpipe(port->serial->dev, 0),
 382					HID_REQ_GET_REPORT,
 383					USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
 384					0x0300, 0, feature_buffer,
 385					feature_len, 500);
 386
 387			if (tries++ >= 3)
 388				break;
 389		} while (retval != feature_len
 390						&& retval != -ENODEV);
 391
 392		if (retval != feature_len) {
 393			dev_err(dev, "%s - failed to retrieve serial line settings - %d\n",
 394				__func__, retval);
 395			cypress_set_dead(port);
 396			goto out;
 397		} else {
 398			spin_lock_irqsave(&priv->lock, flags);
 399			/* store the config in one byte, and later
 400			   use bit masks to check values */
 401			priv->current_config = feature_buffer[4];
 402			priv->baud_rate = get_unaligned_le32(feature_buffer);
 403			spin_unlock_irqrestore(&priv->lock, flags);
 404		}
 405	}
 406	spin_lock_irqsave(&priv->lock, flags);
 407	++priv->cmd_count;
 408	spin_unlock_irqrestore(&priv->lock, flags);
 409out:
 410	kfree(feature_buffer);
 411	return retval;
 412} /* cypress_serial_control */
 413
 414
 415static void cypress_set_dead(struct usb_serial_port *port)
 416{
 417	struct cypress_private *priv = usb_get_serial_port_data(port);
 418	unsigned long flags;
 419
 420	spin_lock_irqsave(&priv->lock, flags);
 421	if (!priv->comm_is_ok) {
 422		spin_unlock_irqrestore(&priv->lock, flags);
 423		return;
 424	}
 425	priv->comm_is_ok = 0;
 426	spin_unlock_irqrestore(&priv->lock, flags);
 427
 428	dev_err(&port->dev, "cypress_m8 suspending failing port %d - "
 429		"interval might be too short\n", port->port_number);
 430}
 431
 432
 433/*****************************************************************************
 434 * Cypress serial driver functions
 435 *****************************************************************************/
 436
 437
 438static int cypress_generic_port_probe(struct usb_serial_port *port)
 439{
 440	struct usb_serial *serial = port->serial;
 441	struct cypress_private *priv;
 442
 443	if (!port->interrupt_out_urb || !port->interrupt_in_urb) {
 444		dev_err(&port->dev, "required endpoint is missing\n");
 445		return -ENODEV;
 446	}
 447
 448	priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL);
 449	if (!priv)
 450		return -ENOMEM;
 451
 452	priv->comm_is_ok = !0;
 453	spin_lock_init(&priv->lock);
 454	if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) {
 455		kfree(priv);
 456		return -ENOMEM;
 457	}
 458
 459	/* Skip reset for FRWD device. It is a workaound:
 460	   device hangs if it receives SET_CONFIGURE in Configured
 461	   state. */
 462	if (!is_frwd(serial->dev))
 463		usb_reset_configuration(serial->dev);
 464
 465	priv->cmd_ctrl = 0;
 466	priv->line_control = 0;
 467	priv->rx_flags = 0;
 468	/* Default packet format setting is determined by packet size.
 469	   Anything with a size larger then 9 must have a separate
 470	   count field since the 3 bit count field is otherwise too
 471	   small.  Otherwise we can use the slightly more compact
 472	   format.  This is in accordance with the cypress_m8 serial
 473	   converter app note. */
 474	if (port->interrupt_out_size > 9)
 475		priv->pkt_fmt = packet_format_1;
 476	else
 477		priv->pkt_fmt = packet_format_2;
 478
 479	if (interval > 0) {
 480		priv->write_urb_interval = interval;
 481		priv->read_urb_interval = interval;
 482		dev_dbg(&port->dev, "%s - read & write intervals forced to %d\n",
 483			__func__, interval);
 484	} else {
 485		priv->write_urb_interval = port->interrupt_out_urb->interval;
 486		priv->read_urb_interval = port->interrupt_in_urb->interval;
 487		dev_dbg(&port->dev, "%s - intervals: read=%d write=%d\n",
 488			__func__, priv->read_urb_interval,
 489			priv->write_urb_interval);
 490	}
 491	usb_set_serial_port_data(port, priv);
 492
 493	port->port.drain_delay = 256;
 494
 495	return 0;
 496}
 497
 498
 499static int cypress_earthmate_port_probe(struct usb_serial_port *port)
 500{
 501	struct usb_serial *serial = port->serial;
 502	struct cypress_private *priv;
 503	int ret;
 504
 505	ret = cypress_generic_port_probe(port);
 506	if (ret) {
 507		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
 508		return ret;
 509	}
 510
 511	priv = usb_get_serial_port_data(port);
 512	priv->chiptype = CT_EARTHMATE;
 513	/* All Earthmate devices use the separated-count packet
 514	   format!  Idiotic. */
 515	priv->pkt_fmt = packet_format_1;
 516	if (serial->dev->descriptor.idProduct !=
 517				cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
 518		/* The old original USB Earthmate seemed able to
 519		   handle GET_CONFIG requests; everything they've
 520		   produced since that time crashes if this command is
 521		   attempted :-( */
 522		dev_dbg(&port->dev,
 523			"%s - Marking this device as unsafe for GET_CONFIG commands\n",
 524			__func__);
 525		priv->get_cfg_unsafe = !0;
 526	}
 527
 528	return 0;
 529}
 530
 531static int cypress_hidcom_port_probe(struct usb_serial_port *port)
 532{
 533	struct cypress_private *priv;
 534	int ret;
 535
 536	ret = cypress_generic_port_probe(port);
 537	if (ret) {
 538		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
 539		return ret;
 540	}
 541
 542	priv = usb_get_serial_port_data(port);
 543	priv->chiptype = CT_CYPHIDCOM;
 544
 545	return 0;
 546}
 547
 548static int cypress_ca42v2_port_probe(struct usb_serial_port *port)
 549{
 550	struct cypress_private *priv;
 551	int ret;
 552
 553	ret = cypress_generic_port_probe(port);
 554	if (ret) {
 555		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
 556		return ret;
 557	}
 558
 559	priv = usb_get_serial_port_data(port);
 560	priv->chiptype = CT_CA42V2;
 561
 562	return 0;
 563}
 564
 565static void cypress_port_remove(struct usb_serial_port *port)
 566{
 567	struct cypress_private *priv;
 568
 569	priv = usb_get_serial_port_data(port);
 570
 571	kfifo_free(&priv->write_fifo);
 572	kfree(priv);
 573}
 574
 575static int cypress_open(struct tty_struct *tty, struct usb_serial_port *port)
 576{
 577	struct cypress_private *priv = usb_get_serial_port_data(port);
 578	struct usb_serial *serial = port->serial;
 579	unsigned long flags;
 580	int result = 0;
 581
 582	if (!priv->comm_is_ok)
 583		return -EIO;
 584
 585	/* clear halts before open */
 586	usb_clear_halt(serial->dev, 0x81);
 587	usb_clear_halt(serial->dev, 0x02);
 588
 589	spin_lock_irqsave(&priv->lock, flags);
 590	/* reset read/write statistics */
 591	priv->bytes_in = 0;
 592	priv->bytes_out = 0;
 593	priv->cmd_count = 0;
 594	priv->rx_flags = 0;
 595	spin_unlock_irqrestore(&priv->lock, flags);
 596
 597	/* Set termios */
 598	cypress_send(port);
 599
 600	if (tty)
 601		cypress_set_termios(tty, port, NULL);
 602
 603	/* setup the port and start reading from the device */
 604	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
 605		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
 606		port->interrupt_in_urb->transfer_buffer,
 607		port->interrupt_in_urb->transfer_buffer_length,
 608		cypress_read_int_callback, port, priv->read_urb_interval);
 609	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 610
 611	if (result) {
 612		dev_err(&port->dev,
 613			"%s - failed submitting read urb, error %d\n",
 614							__func__, result);
 615		cypress_set_dead(port);
 616	}
 617
 618	return result;
 619} /* cypress_open */
 620
 621static void cypress_dtr_rts(struct usb_serial_port *port, int on)
 622{
 623	struct cypress_private *priv = usb_get_serial_port_data(port);
 624	/* drop dtr and rts */
 625	spin_lock_irq(&priv->lock);
 626	if (on == 0)
 627		priv->line_control = 0;
 628	else 
 629		priv->line_control = CONTROL_DTR | CONTROL_RTS;
 630	priv->cmd_ctrl = 1;
 631	spin_unlock_irq(&priv->lock);
 632	cypress_write(NULL, port, NULL, 0);
 633}
 634
 635static void cypress_close(struct usb_serial_port *port)
 636{
 637	struct cypress_private *priv = usb_get_serial_port_data(port);
 638	unsigned long flags;
 639
 640	spin_lock_irqsave(&priv->lock, flags);
 641	kfifo_reset_out(&priv->write_fifo);
 642	spin_unlock_irqrestore(&priv->lock, flags);
 643
 644	dev_dbg(&port->dev, "%s - stopping urbs\n", __func__);
 645	usb_kill_urb(port->interrupt_in_urb);
 646	usb_kill_urb(port->interrupt_out_urb);
 647
 648	if (stats)
 649		dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
 650			priv->bytes_in, priv->bytes_out, priv->cmd_count);
 651} /* cypress_close */
 652
 653
 654static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
 655					const unsigned char *buf, int count)
 656{
 657	struct cypress_private *priv = usb_get_serial_port_data(port);
 658
 659	dev_dbg(&port->dev, "%s - %d bytes\n", __func__, count);
 660
 661	/* line control commands, which need to be executed immediately,
 662	   are not put into the buffer for obvious reasons.
 663	 */
 664	if (priv->cmd_ctrl) {
 665		count = 0;
 666		goto finish;
 667	}
 668
 669	if (!count)
 670		return count;
 671
 672	count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
 673
 674finish:
 675	cypress_send(port);
 676
 677	return count;
 678} /* cypress_write */
 679
 680
 681static void cypress_send(struct usb_serial_port *port)
 682{
 683	int count = 0, result, offset, actual_size;
 684	struct cypress_private *priv = usb_get_serial_port_data(port);
 685	struct device *dev = &port->dev;
 686	unsigned long flags;
 687
 688	if (!priv->comm_is_ok)
 689		return;
 690
 691	dev_dbg(dev, "%s - interrupt out size is %d\n", __func__,
 692		port->interrupt_out_size);
 693
 694	spin_lock_irqsave(&priv->lock, flags);
 695	if (priv->write_urb_in_use) {
 696		dev_dbg(dev, "%s - can't write, urb in use\n", __func__);
 697		spin_unlock_irqrestore(&priv->lock, flags);
 698		return;
 699	}
 700	spin_unlock_irqrestore(&priv->lock, flags);
 701
 702	/* clear buffer */
 703	memset(port->interrupt_out_urb->transfer_buffer, 0,
 704						port->interrupt_out_size);
 705
 706	spin_lock_irqsave(&priv->lock, flags);
 707	switch (priv->pkt_fmt) {
 708	default:
 709	case packet_format_1:
 710		/* this is for the CY7C64013... */
 711		offset = 2;
 712		port->interrupt_out_buffer[0] = priv->line_control;
 713		break;
 714	case packet_format_2:
 715		/* this is for the CY7C63743... */
 716		offset = 1;
 717		port->interrupt_out_buffer[0] = priv->line_control;
 718		break;
 719	}
 720
 721	if (priv->line_control & CONTROL_RESET)
 722		priv->line_control &= ~CONTROL_RESET;
 723
 724	if (priv->cmd_ctrl) {
 725		priv->cmd_count++;
 726		dev_dbg(dev, "%s - line control command being issued\n", __func__);
 727		spin_unlock_irqrestore(&priv->lock, flags);
 728		goto send;
 729	} else
 730		spin_unlock_irqrestore(&priv->lock, flags);
 731
 732	count = kfifo_out_locked(&priv->write_fifo,
 733					&port->interrupt_out_buffer[offset],
 734					port->interrupt_out_size - offset,
 735					&priv->lock);
 736	if (count == 0)
 737		return;
 738
 739	switch (priv->pkt_fmt) {
 740	default:
 741	case packet_format_1:
 742		port->interrupt_out_buffer[1] = count;
 743		break;
 744	case packet_format_2:
 745		port->interrupt_out_buffer[0] |= count;
 746	}
 747
 748	dev_dbg(dev, "%s - count is %d\n", __func__, count);
 749
 750send:
 751	spin_lock_irqsave(&priv->lock, flags);
 752	priv->write_urb_in_use = 1;
 753	spin_unlock_irqrestore(&priv->lock, flags);
 754
 755	if (priv->cmd_ctrl)
 756		actual_size = 1;
 757	else
 758		actual_size = count +
 759			      (priv->pkt_fmt == packet_format_1 ? 2 : 1);
 760
 761	usb_serial_debug_data(dev, __func__, port->interrupt_out_size,
 762			      port->interrupt_out_urb->transfer_buffer);
 763
 764	usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
 765		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
 766		port->interrupt_out_buffer, actual_size,
 767		cypress_write_int_callback, port, priv->write_urb_interval);
 768	result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
 769	if (result) {
 770		dev_err_console(port,
 771				"%s - failed submitting write urb, error %d\n",
 772							__func__, result);
 773		priv->write_urb_in_use = 0;
 774		cypress_set_dead(port);
 775	}
 776
 777	spin_lock_irqsave(&priv->lock, flags);
 778	if (priv->cmd_ctrl)
 779		priv->cmd_ctrl = 0;
 780
 781	/* do not count the line control and size bytes */
 782	priv->bytes_out += count;
 783	spin_unlock_irqrestore(&priv->lock, flags);
 784
 785	usb_serial_port_softint(port);
 786} /* cypress_send */
 787
 788
 789/* returns how much space is available in the soft buffer */
 790static unsigned int cypress_write_room(struct tty_struct *tty)
 791{
 792	struct usb_serial_port *port = tty->driver_data;
 793	struct cypress_private *priv = usb_get_serial_port_data(port);
 794	unsigned int room;
 795	unsigned long flags;
 796
 797	spin_lock_irqsave(&priv->lock, flags);
 798	room = kfifo_avail(&priv->write_fifo);
 799	spin_unlock_irqrestore(&priv->lock, flags);
 800
 801	dev_dbg(&port->dev, "%s - returns %u\n", __func__, room);
 802	return room;
 803}
 804
 805
 806static int cypress_tiocmget(struct tty_struct *tty)
 807{
 808	struct usb_serial_port *port = tty->driver_data;
 809	struct cypress_private *priv = usb_get_serial_port_data(port);
 810	__u8 status, control;
 811	unsigned int result = 0;
 812	unsigned long flags;
 813
 814	spin_lock_irqsave(&priv->lock, flags);
 815	control = priv->line_control;
 816	status = priv->current_status;
 817	spin_unlock_irqrestore(&priv->lock, flags);
 818
 819	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
 820		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
 821		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
 822		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
 823		| ((status & UART_RI)         ? TIOCM_RI  : 0)
 824		| ((status & UART_CD)         ? TIOCM_CD  : 0);
 825
 826	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
 827
 828	return result;
 829}
 830
 831
 832static int cypress_tiocmset(struct tty_struct *tty,
 833			       unsigned int set, unsigned int clear)
 834{
 835	struct usb_serial_port *port = tty->driver_data;
 836	struct cypress_private *priv = usb_get_serial_port_data(port);
 837	unsigned long flags;
 838
 839	spin_lock_irqsave(&priv->lock, flags);
 840	if (set & TIOCM_RTS)
 841		priv->line_control |= CONTROL_RTS;
 842	if (set & TIOCM_DTR)
 843		priv->line_control |= CONTROL_DTR;
 844	if (clear & TIOCM_RTS)
 845		priv->line_control &= ~CONTROL_RTS;
 846	if (clear & TIOCM_DTR)
 847		priv->line_control &= ~CONTROL_DTR;
 848	priv->cmd_ctrl = 1;
 849	spin_unlock_irqrestore(&priv->lock, flags);
 850
 851	return cypress_write(tty, port, NULL, 0);
 852}
 853
 854static void cypress_earthmate_init_termios(struct tty_struct *tty)
 855{
 856	tty_encode_baud_rate(tty, 4800, 4800);
 857}
 858
 859static void cypress_set_termios(struct tty_struct *tty,
 860				struct usb_serial_port *port,
 861				const struct ktermios *old_termios)
 862{
 863	struct cypress_private *priv = usb_get_serial_port_data(port);
 864	struct device *dev = &port->dev;
 865	int data_bits, stop_bits, parity_type, parity_enable;
 866	unsigned int cflag;
 867	unsigned long flags;
 868	__u8 oldlines;
 869	int linechange = 0;
 870
 871	/* Unsupported features need clearing */
 872	tty->termios.c_cflag &= ~(CMSPAR|CRTSCTS);
 873
 874	cflag = tty->termios.c_cflag;
 875
 876	/* set number of data bits, parity, stop bits */
 877	/* when parity is disabled the parity type bit is ignored */
 878
 879	/* 1 means 2 stop bits, 0 means 1 stop bit */
 880	stop_bits = cflag & CSTOPB ? 1 : 0;
 881
 882	if (cflag & PARENB) {
 883		parity_enable = 1;
 884		/* 1 means odd parity, 0 means even parity */
 885		parity_type = cflag & PARODD ? 1 : 0;
 886	} else
 887		parity_enable = parity_type = 0;
 888
 889	data_bits = tty_get_char_size(cflag);
 890
 891	spin_lock_irqsave(&priv->lock, flags);
 892	oldlines = priv->line_control;
 893	if ((cflag & CBAUD) == B0) {
 894		/* drop dtr and rts */
 895		dev_dbg(dev, "%s - dropping the lines, baud rate 0bps\n", __func__);
 896		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 897	} else
 898		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
 899	spin_unlock_irqrestore(&priv->lock, flags);
 900
 901	dev_dbg(dev, "%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)\n",
 902		__func__, stop_bits, parity_enable, parity_type, data_bits);
 903
 904	cypress_serial_control(tty, port, tty_get_baud_rate(tty),
 905			data_bits, stop_bits,
 906			parity_enable, parity_type,
 907			0, CYPRESS_SET_CONFIG);
 908
 909	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
 910	 * filled into the private structure this should confirm that all is
 911	 * working if it returns what we just set */
 912	cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
 913
 914	/* Here we can define custom tty settings for devices; the main tty
 915	 * termios flag base comes from empeg.c */
 916
 917	spin_lock_irqsave(&priv->lock, flags);
 918	if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
 919		dev_dbg(dev, "Using custom termios settings for a baud rate of 4800bps.\n");
 920		/* define custom termios settings for NMEA protocol */
 921
 922		tty->termios.c_iflag /* input modes - */
 923			&= ~(IGNBRK  /* disable ignore break */
 924			| BRKINT     /* disable break causes interrupt */
 925			| PARMRK     /* disable mark parity errors */
 926			| ISTRIP     /* disable clear high bit of input char */
 927			| INLCR      /* disable translate NL to CR */
 928			| IGNCR      /* disable ignore CR */
 929			| ICRNL      /* disable translate CR to NL */
 930			| IXON);     /* disable enable XON/XOFF flow control */
 931
 932		tty->termios.c_oflag /* output modes */
 933			&= ~OPOST;    /* disable postprocess output char */
 934
 935		tty->termios.c_lflag /* line discipline modes */
 936			&= ~(ECHO     /* disable echo input characters */
 937			| ECHONL      /* disable echo new line */
 938			| ICANON      /* disable erase, kill, werase, and rprnt
 939					 special characters */
 940			| ISIG        /* disable interrupt, quit, and suspend
 941					 special characters */
 942			| IEXTEN);    /* disable non-POSIX special characters */
 943	} /* CT_CYPHIDCOM: Application should handle this for device */
 944
 945	linechange = (priv->line_control != oldlines);
 946	spin_unlock_irqrestore(&priv->lock, flags);
 947
 948	/* if necessary, set lines */
 949	if (linechange) {
 950		priv->cmd_ctrl = 1;
 951		cypress_write(tty, port, NULL, 0);
 952	}
 953} /* cypress_set_termios */
 954
 955
 956/* returns amount of data still left in soft buffer */
 957static unsigned int cypress_chars_in_buffer(struct tty_struct *tty)
 958{
 959	struct usb_serial_port *port = tty->driver_data;
 960	struct cypress_private *priv = usb_get_serial_port_data(port);
 961	unsigned int chars;
 962	unsigned long flags;
 963
 964	spin_lock_irqsave(&priv->lock, flags);
 965	chars = kfifo_len(&priv->write_fifo);
 966	spin_unlock_irqrestore(&priv->lock, flags);
 967
 968	dev_dbg(&port->dev, "%s - returns %u\n", __func__, chars);
 969	return chars;
 970}
 971
 972
 973static void cypress_throttle(struct tty_struct *tty)
 974{
 975	struct usb_serial_port *port = tty->driver_data;
 976	struct cypress_private *priv = usb_get_serial_port_data(port);
 977
 978	spin_lock_irq(&priv->lock);
 979	priv->rx_flags = THROTTLED;
 980	spin_unlock_irq(&priv->lock);
 981}
 982
 983
 984static void cypress_unthrottle(struct tty_struct *tty)
 985{
 986	struct usb_serial_port *port = tty->driver_data;
 987	struct cypress_private *priv = usb_get_serial_port_data(port);
 988	int actually_throttled, result;
 989
 990	spin_lock_irq(&priv->lock);
 991	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
 992	priv->rx_flags = 0;
 993	spin_unlock_irq(&priv->lock);
 994
 995	if (!priv->comm_is_ok)
 996		return;
 997
 998	if (actually_throttled) {
 999		result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
1000		if (result) {
1001			dev_err(&port->dev, "%s - failed submitting read urb, "
1002					"error %d\n", __func__, result);
1003			cypress_set_dead(port);
1004		}
1005	}
1006}
1007
1008
1009static void cypress_read_int_callback(struct urb *urb)
1010{
1011	struct usb_serial_port *port = urb->context;
1012	struct cypress_private *priv = usb_get_serial_port_data(port);
1013	struct device *dev = &urb->dev->dev;
1014	struct tty_struct *tty;
1015	unsigned char *data = urb->transfer_buffer;
1016	unsigned long flags;
1017	char tty_flag = TTY_NORMAL;
1018	int bytes = 0;
1019	int result;
1020	int i = 0;
1021	int status = urb->status;
1022
1023	switch (status) {
1024	case 0: /* success */
1025		break;
1026	case -ECONNRESET:
1027	case -ENOENT:
1028	case -ESHUTDOWN:
1029		/* precursor to disconnect so just go away */
1030		return;
1031	case -EPIPE:
1032		/* Can't call usb_clear_halt while in_interrupt */
1033		fallthrough;
1034	default:
1035		/* something ugly is going on... */
1036		dev_err(dev, "%s - unexpected nonzero read status received: %d\n",
1037			__func__, status);
1038		cypress_set_dead(port);
1039		return;
1040	}
1041
1042	spin_lock_irqsave(&priv->lock, flags);
1043	if (priv->rx_flags & THROTTLED) {
1044		dev_dbg(dev, "%s - now throttling\n", __func__);
1045		priv->rx_flags |= ACTUALLY_THROTTLED;
1046		spin_unlock_irqrestore(&priv->lock, flags);
1047		return;
1048	}
1049	spin_unlock_irqrestore(&priv->lock, flags);
1050
1051	tty = tty_port_tty_get(&port->port);
1052	if (!tty) {
1053		dev_dbg(dev, "%s - bad tty pointer - exiting\n", __func__);
1054		return;
1055	}
1056
1057	spin_lock_irqsave(&priv->lock, flags);
1058	result = urb->actual_length;
1059	switch (priv->pkt_fmt) {
1060	default:
1061	case packet_format_1:
1062		/* This is for the CY7C64013... */
1063		priv->current_status = data[0] & 0xF8;
1064		bytes = data[1] + 2;
1065		i = 2;
1066		break;
1067	case packet_format_2:
1068		/* This is for the CY7C63743... */
1069		priv->current_status = data[0] & 0xF8;
1070		bytes = (data[0] & 0x07) + 1;
1071		i = 1;
1072		break;
1073	}
1074	spin_unlock_irqrestore(&priv->lock, flags);
1075	if (result < bytes) {
1076		dev_dbg(dev,
1077			"%s - wrong packet size - received %d bytes but packet said %d bytes\n",
1078			__func__, result, bytes);
1079		goto continue_read;
1080	}
1081
1082	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
1083
1084	spin_lock_irqsave(&priv->lock, flags);
1085	/* check to see if status has changed */
1086	if (priv->current_status != priv->prev_status) {
1087		u8 delta = priv->current_status ^ priv->prev_status;
1088
1089		if (delta & UART_MSR_MASK) {
1090			if (delta & UART_CTS)
1091				port->icount.cts++;
1092			if (delta & UART_DSR)
1093				port->icount.dsr++;
1094			if (delta & UART_RI)
1095				port->icount.rng++;
1096			if (delta & UART_CD)
1097				port->icount.dcd++;
1098
1099			wake_up_interruptible(&port->port.delta_msr_wait);
1100		}
1101
1102		priv->prev_status = priv->current_status;
1103	}
1104	spin_unlock_irqrestore(&priv->lock, flags);
1105
1106	/* hangup, as defined in acm.c... this might be a bad place for it
1107	 * though */
1108	if (tty && !C_CLOCAL(tty) && !(priv->current_status & UART_CD)) {
1109		dev_dbg(dev, "%s - calling hangup\n", __func__);
1110		tty_hangup(tty);
1111		goto continue_read;
1112	}
1113
1114	/* There is one error bit... I'm assuming it is a parity error
1115	 * indicator as the generic firmware will set this bit to 1 if a
1116	 * parity error occurs.
1117	 * I can not find reference to any other error events. */
1118	spin_lock_irqsave(&priv->lock, flags);
1119	if (priv->current_status & CYP_ERROR) {
1120		spin_unlock_irqrestore(&priv->lock, flags);
1121		tty_flag = TTY_PARITY;
1122		dev_dbg(dev, "%s - Parity Error detected\n", __func__);
1123	} else
1124		spin_unlock_irqrestore(&priv->lock, flags);
1125
1126	/* process read if there is data other than line status */
1127	if (bytes > i) {
1128		tty_insert_flip_string_fixed_flag(&port->port, data + i,
1129				tty_flag, bytes - i);
1130		tty_flip_buffer_push(&port->port);
1131	}
1132
1133	spin_lock_irqsave(&priv->lock, flags);
1134	/* control and status byte(s) are also counted */
1135	priv->bytes_in += bytes;
1136	spin_unlock_irqrestore(&priv->lock, flags);
1137
1138continue_read:
1139	tty_kref_put(tty);
1140
1141	/* Continue trying to always read */
1142
1143	if (priv->comm_is_ok) {
1144		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1145				usb_rcvintpipe(port->serial->dev,
1146					port->interrupt_in_endpointAddress),
1147				port->interrupt_in_urb->transfer_buffer,
1148				port->interrupt_in_urb->transfer_buffer_length,
1149				cypress_read_int_callback, port,
1150				priv->read_urb_interval);
1151		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1152		if (result && result != -EPERM) {
1153			dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
1154				__func__, result);
1155			cypress_set_dead(port);
1156		}
1157	}
1158} /* cypress_read_int_callback */
1159
1160
1161static void cypress_write_int_callback(struct urb *urb)
1162{
1163	struct usb_serial_port *port = urb->context;
1164	struct cypress_private *priv = usb_get_serial_port_data(port);
1165	struct device *dev = &urb->dev->dev;
1166	int status = urb->status;
1167
1168	switch (status) {
1169	case 0:
1170		/* success */
1171		break;
1172	case -ECONNRESET:
1173	case -ENOENT:
1174	case -ESHUTDOWN:
1175		/* this urb is terminated, clean up */
1176		dev_dbg(dev, "%s - urb shutting down with status: %d\n",
1177			__func__, status);
1178		priv->write_urb_in_use = 0;
1179		return;
1180	case -EPIPE:
1181		/* Cannot call usb_clear_halt while in_interrupt */
1182		fallthrough;
1183	default:
1184		dev_err(dev, "%s - unexpected nonzero write status received: %d\n",
1185			__func__, status);
1186		cypress_set_dead(port);
1187		break;
1188	}
1189	priv->write_urb_in_use = 0;
1190
1191	/* send any buffered data */
1192	cypress_send(port);
1193}
1194
1195module_usb_serial_driver(serial_drivers, id_table_combined);
1196
1197MODULE_AUTHOR(DRIVER_AUTHOR);
1198MODULE_DESCRIPTION(DRIVER_DESC);
1199MODULE_LICENSE("GPL");
1200
1201module_param(stats, bool, 0644);
1202MODULE_PARM_DESC(stats, "Enable statistics or not");
1203module_param(interval, int, 0644);
1204MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1205module_param(unstable_bauds, bool, 0644);
1206MODULE_PARM_DESC(unstable_bauds, "Allow unstable baud rates");