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 <asm/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		.owner =		THIS_MODULE,
143		.name =			"earthmate",
144	},
145	.description =			"DeLorme Earthmate USB",
146	.id_table =			id_table_earthmate,
147	.num_ports =			1,
148	.port_probe =			cypress_earthmate_port_probe,
149	.port_remove =			cypress_port_remove,
150	.open =				cypress_open,
151	.close =			cypress_close,
152	.dtr_rts =			cypress_dtr_rts,
153	.write =			cypress_write,
154	.write_room =			cypress_write_room,
155	.init_termios =			cypress_earthmate_init_termios,
156	.set_termios =			cypress_set_termios,
157	.tiocmget =			cypress_tiocmget,
158	.tiocmset =			cypress_tiocmset,
159	.tiocmiwait =			usb_serial_generic_tiocmiwait,
160	.chars_in_buffer =		cypress_chars_in_buffer,
161	.throttle =		 	cypress_throttle,
162	.unthrottle =			cypress_unthrottle,
163	.read_int_callback =		cypress_read_int_callback,
164	.write_int_callback =		cypress_write_int_callback,
165};
166
167static struct usb_serial_driver cypress_hidcom_device = {
168	.driver = {
169		.owner =		THIS_MODULE,
170		.name =			"cyphidcom",
171	},
172	.description =			"HID->COM RS232 Adapter",
173	.id_table =			id_table_cyphidcomrs232,
174	.num_ports =			1,
175	.port_probe =			cypress_hidcom_port_probe,
176	.port_remove =			cypress_port_remove,
177	.open =				cypress_open,
178	.close =			cypress_close,
179	.dtr_rts =			cypress_dtr_rts,
180	.write =			cypress_write,
181	.write_room =			cypress_write_room,
182	.set_termios =			cypress_set_termios,
183	.tiocmget =			cypress_tiocmget,
184	.tiocmset =			cypress_tiocmset,
185	.tiocmiwait =			usb_serial_generic_tiocmiwait,
186	.chars_in_buffer =		cypress_chars_in_buffer,
187	.throttle =			cypress_throttle,
188	.unthrottle =			cypress_unthrottle,
189	.read_int_callback =		cypress_read_int_callback,
190	.write_int_callback =		cypress_write_int_callback,
191};
192
193static struct usb_serial_driver cypress_ca42v2_device = {
194	.driver = {
195		.owner =		THIS_MODULE,
196		.name =			"nokiaca42v2",
197	},
198	.description =			"Nokia CA-42 V2 Adapter",
199	.id_table =			id_table_nokiaca42v2,
200	.num_ports =			1,
201	.port_probe =			cypress_ca42v2_port_probe,
202	.port_remove =			cypress_port_remove,
203	.open =				cypress_open,
204	.close =			cypress_close,
205	.dtr_rts =			cypress_dtr_rts,
206	.write =			cypress_write,
207	.write_room =			cypress_write_room,
208	.set_termios =			cypress_set_termios,
209	.tiocmget =			cypress_tiocmget,
210	.tiocmset =			cypress_tiocmset,
211	.tiocmiwait =			usb_serial_generic_tiocmiwait,
212	.chars_in_buffer =		cypress_chars_in_buffer,
213	.throttle =			cypress_throttle,
214	.unthrottle =			cypress_unthrottle,
215	.read_int_callback =		cypress_read_int_callback,
216	.write_int_callback =		cypress_write_int_callback,
217};
218
219static struct usb_serial_driver * const serial_drivers[] = {
220	&cypress_earthmate_device, &cypress_hidcom_device,
221	&cypress_ca42v2_device, NULL
222};
223
224/*****************************************************************************
225 * Cypress serial helper functions
226 *****************************************************************************/
227
228/* FRWD Dongle hidcom needs to skip reset and speed checks */
229static inline bool is_frwd(struct usb_device *dev)
230{
231	return ((le16_to_cpu(dev->descriptor.idVendor) == VENDOR_ID_FRWD) &&
232		(le16_to_cpu(dev->descriptor.idProduct) == PRODUCT_ID_CYPHIDCOM_FRWD));
233}
234
235static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
236{
237	struct cypress_private *priv;
238	priv = usb_get_serial_port_data(port);
239
240	if (unstable_bauds)
241		return new_rate;
242
243	/* FRWD Dongle uses 115200 bps */
244	if (is_frwd(port->serial->dev))
245		return new_rate;
246
247	/*
248	 * The general purpose firmware for the Cypress M8 allows for
249	 * a maximum speed of 57600bps (I have no idea whether DeLorme
250	 * chose to use the general purpose firmware or not), if you
251	 * need to modify this speed setting for your own project
252	 * please add your own chiptype and modify the code likewise.
253	 * The Cypress HID->COM device will work successfully up to
254	 * 115200bps (but the actual throughput is around 3kBps).
255	 */
256	if (port->serial->dev->speed == USB_SPEED_LOW) {
257		/*
258		 * Mike Isely <isely@pobox.com> 2-Feb-2008: The
259		 * Cypress app note that describes this mechanism
260		 * states that the low-speed part can't handle more
261		 * than 800 bytes/sec, in which case 4800 baud is the
262		 * safest speed for a part like that.
263		 */
264		if (new_rate > 4800) {
265			dev_dbg(&port->dev,
266				"%s - failed setting baud rate, device incapable speed %d\n",
267				__func__, new_rate);
268			return -1;
269		}
270	}
271	switch (priv->chiptype) {
272	case CT_EARTHMATE:
273		if (new_rate <= 600) {
274			/* 300 and 600 baud rates are supported under
275			 * the generic firmware, but are not used with
276			 * NMEA and SiRF protocols */
277			dev_dbg(&port->dev,
278				"%s - failed setting baud rate, unsupported speed of %d on Earthmate GPS\n",
279				__func__, new_rate);
280			return -1;
281		}
282		break;
283	default:
284		break;
285	}
286	return new_rate;
287}
288
289
290/* This function can either set or retrieve the current serial line settings */
291static int cypress_serial_control(struct tty_struct *tty,
292	struct usb_serial_port *port, speed_t baud_rate, int data_bits,
293	int stop_bits, int parity_enable, int parity_type, int reset,
294	int cypress_request_type)
295{
296	int new_baudrate = 0, retval = 0, tries = 0;
297	struct cypress_private *priv;
298	struct device *dev = &port->dev;
299	u8 *feature_buffer;
300	const unsigned int feature_len = 5;
301	unsigned long flags;
302
303	priv = usb_get_serial_port_data(port);
304
305	if (!priv->comm_is_ok)
306		return -ENODEV;
307
308	feature_buffer = kcalloc(feature_len, sizeof(u8), GFP_KERNEL);
309	if (!feature_buffer)
310		return -ENOMEM;
311
312	switch (cypress_request_type) {
313	case CYPRESS_SET_CONFIG:
314		/* 0 means 'Hang up' so doesn't change the true bit rate */
315		new_baudrate = priv->baud_rate;
316		if (baud_rate && baud_rate != priv->baud_rate) {
317			dev_dbg(dev, "%s - baud rate is changing\n", __func__);
318			retval = analyze_baud_rate(port, baud_rate);
319			if (retval >= 0) {
320				new_baudrate = retval;
321				dev_dbg(dev, "%s - New baud rate set to %d\n",
322					__func__, new_baudrate);
323			}
324		}
325		dev_dbg(dev, "%s - baud rate is being sent as %d\n", __func__,
326			new_baudrate);
327
328		/* fill the feature_buffer with new configuration */
329		put_unaligned_le32(new_baudrate, feature_buffer);
330		feature_buffer[4] |= data_bits - 5;   /* assign data bits in 2 bit space ( max 3 ) */
331		/* 1 bit gap */
332		feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
333		feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
334		feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
335		/* 1 bit gap */
336		feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
337
338		dev_dbg(dev, "%s - device is being sent this feature report:\n", __func__);
339		dev_dbg(dev, "%s - %02X - %02X - %02X - %02X - %02X\n", __func__,
340			feature_buffer[0], feature_buffer[1],
341			feature_buffer[2], feature_buffer[3],
342			feature_buffer[4]);
343
344		do {
345			retval = usb_control_msg(port->serial->dev,
346					usb_sndctrlpipe(port->serial->dev, 0),
347					HID_REQ_SET_REPORT,
348					USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
349					0x0300, 0, feature_buffer,
350					feature_len, 500);
351
352			if (tries++ >= 3)
353				break;
354
355		} while (retval != feature_len &&
356			 retval != -ENODEV);
357
358		if (retval != feature_len) {
359			dev_err(dev, "%s - failed sending serial line settings - %d\n",
360				__func__, retval);
361			cypress_set_dead(port);
362		} else {
363			spin_lock_irqsave(&priv->lock, flags);
364			priv->baud_rate = new_baudrate;
365			priv->current_config = feature_buffer[4];
366			spin_unlock_irqrestore(&priv->lock, flags);
367			/* If we asked for a speed change encode it */
368			if (baud_rate)
369				tty_encode_baud_rate(tty,
370					new_baudrate, new_baudrate);
371		}
372	break;
373	case CYPRESS_GET_CONFIG:
374		if (priv->get_cfg_unsafe) {
375			/* Not implemented for this device,
376			   and if we try to do it we're likely
377			   to crash the hardware. */
378			retval = -ENOTTY;
379			goto out;
380		}
381		dev_dbg(dev, "%s - retrieving serial line settings\n", __func__);
382		do {
383			retval = usb_control_msg(port->serial->dev,
384					usb_rcvctrlpipe(port->serial->dev, 0),
385					HID_REQ_GET_REPORT,
386					USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
387					0x0300, 0, feature_buffer,
388					feature_len, 500);
389
390			if (tries++ >= 3)
391				break;
392		} while (retval != feature_len
393						&& retval != -ENODEV);
394
395		if (retval != feature_len) {
396			dev_err(dev, "%s - failed to retrieve serial line settings - %d\n",
397				__func__, retval);
398			cypress_set_dead(port);
399			goto out;
400		} else {
401			spin_lock_irqsave(&priv->lock, flags);
402			/* store the config in one byte, and later
403			   use bit masks to check values */
404			priv->current_config = feature_buffer[4];
405			priv->baud_rate = get_unaligned_le32(feature_buffer);
406			spin_unlock_irqrestore(&priv->lock, flags);
407		}
408	}
409	spin_lock_irqsave(&priv->lock, flags);
410	++priv->cmd_count;
411	spin_unlock_irqrestore(&priv->lock, flags);
412out:
413	kfree(feature_buffer);
414	return retval;
415} /* cypress_serial_control */
416
417
418static void cypress_set_dead(struct usb_serial_port *port)
419{
420	struct cypress_private *priv = usb_get_serial_port_data(port);
421	unsigned long flags;
422
423	spin_lock_irqsave(&priv->lock, flags);
424	if (!priv->comm_is_ok) {
425		spin_unlock_irqrestore(&priv->lock, flags);
426		return;
427	}
428	priv->comm_is_ok = 0;
429	spin_unlock_irqrestore(&priv->lock, flags);
430
431	dev_err(&port->dev, "cypress_m8 suspending failing port %d - "
432		"interval might be too short\n", port->port_number);
433}
434
435
436/*****************************************************************************
437 * Cypress serial driver functions
438 *****************************************************************************/
439
440
441static int cypress_generic_port_probe(struct usb_serial_port *port)
442{
443	struct usb_serial *serial = port->serial;
444	struct cypress_private *priv;
445
446	if (!port->interrupt_out_urb || !port->interrupt_in_urb) {
447		dev_err(&port->dev, "required endpoint is missing\n");
448		return -ENODEV;
449	}
450
451	priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL);
452	if (!priv)
453		return -ENOMEM;
454
455	priv->comm_is_ok = !0;
456	spin_lock_init(&priv->lock);
457	if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) {
458		kfree(priv);
459		return -ENOMEM;
460	}
461
462	/* Skip reset for FRWD device. It is a workaound:
463	   device hangs if it receives SET_CONFIGURE in Configured
464	   state. */
465	if (!is_frwd(serial->dev))
466		usb_reset_configuration(serial->dev);
467
468	priv->cmd_ctrl = 0;
469	priv->line_control = 0;
470	priv->rx_flags = 0;
471	/* Default packet format setting is determined by packet size.
472	   Anything with a size larger then 9 must have a separate
473	   count field since the 3 bit count field is otherwise too
474	   small.  Otherwise we can use the slightly more compact
475	   format.  This is in accordance with the cypress_m8 serial
476	   converter app note. */
477	if (port->interrupt_out_size > 9)
478		priv->pkt_fmt = packet_format_1;
479	else
480		priv->pkt_fmt = packet_format_2;
481
482	if (interval > 0) {
483		priv->write_urb_interval = interval;
484		priv->read_urb_interval = interval;
485		dev_dbg(&port->dev, "%s - read & write intervals forced to %d\n",
486			__func__, interval);
487	} else {
488		priv->write_urb_interval = port->interrupt_out_urb->interval;
489		priv->read_urb_interval = port->interrupt_in_urb->interval;
490		dev_dbg(&port->dev, "%s - intervals: read=%d write=%d\n",
491			__func__, priv->read_urb_interval,
492			priv->write_urb_interval);
493	}
494	usb_set_serial_port_data(port, priv);
495
496	port->port.drain_delay = 256;
497
498	return 0;
499}
500
501
502static int cypress_earthmate_port_probe(struct usb_serial_port *port)
503{
504	struct usb_serial *serial = port->serial;
505	struct cypress_private *priv;
506	int ret;
507
508	ret = cypress_generic_port_probe(port);
509	if (ret) {
510		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
511		return ret;
512	}
513
514	priv = usb_get_serial_port_data(port);
515	priv->chiptype = CT_EARTHMATE;
516	/* All Earthmate devices use the separated-count packet
517	   format!  Idiotic. */
518	priv->pkt_fmt = packet_format_1;
519	if (serial->dev->descriptor.idProduct !=
520				cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
521		/* The old original USB Earthmate seemed able to
522		   handle GET_CONFIG requests; everything they've
523		   produced since that time crashes if this command is
524		   attempted :-( */
525		dev_dbg(&port->dev,
526			"%s - Marking this device as unsafe for GET_CONFIG commands\n",
527			__func__);
528		priv->get_cfg_unsafe = !0;
529	}
530
531	return 0;
532}
533
534static int cypress_hidcom_port_probe(struct usb_serial_port *port)
535{
536	struct cypress_private *priv;
537	int ret;
538
539	ret = cypress_generic_port_probe(port);
540	if (ret) {
541		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
542		return ret;
543	}
544
545	priv = usb_get_serial_port_data(port);
546	priv->chiptype = CT_CYPHIDCOM;
547
548	return 0;
549}
550
551static int cypress_ca42v2_port_probe(struct usb_serial_port *port)
552{
553	struct cypress_private *priv;
554	int ret;
555
556	ret = cypress_generic_port_probe(port);
557	if (ret) {
558		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
559		return ret;
560	}
561
562	priv = usb_get_serial_port_data(port);
563	priv->chiptype = CT_CA42V2;
564
565	return 0;
566}
567
568static void cypress_port_remove(struct usb_serial_port *port)
569{
570	struct cypress_private *priv;
571
572	priv = usb_get_serial_port_data(port);
573
574	kfifo_free(&priv->write_fifo);
575	kfree(priv);
576}
577
578static int cypress_open(struct tty_struct *tty, struct usb_serial_port *port)
579{
580	struct cypress_private *priv = usb_get_serial_port_data(port);
581	struct usb_serial *serial = port->serial;
582	unsigned long flags;
583	int result = 0;
584
585	if (!priv->comm_is_ok)
586		return -EIO;
587
588	/* clear halts before open */
589	usb_clear_halt(serial->dev, 0x81);
590	usb_clear_halt(serial->dev, 0x02);
591
592	spin_lock_irqsave(&priv->lock, flags);
593	/* reset read/write statistics */
594	priv->bytes_in = 0;
595	priv->bytes_out = 0;
596	priv->cmd_count = 0;
597	priv->rx_flags = 0;
598	spin_unlock_irqrestore(&priv->lock, flags);
599
600	/* Set termios */
601	cypress_send(port);
602
603	if (tty)
604		cypress_set_termios(tty, port, NULL);
605
606	/* setup the port and start reading from the device */
607	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
608		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
609		port->interrupt_in_urb->transfer_buffer,
610		port->interrupt_in_urb->transfer_buffer_length,
611		cypress_read_int_callback, port, priv->read_urb_interval);
612	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
613
614	if (result) {
615		dev_err(&port->dev,
616			"%s - failed submitting read urb, error %d\n",
617							__func__, result);
618		cypress_set_dead(port);
619	}
620
621	return result;
622} /* cypress_open */
623
624static void cypress_dtr_rts(struct usb_serial_port *port, int on)
625{
626	struct cypress_private *priv = usb_get_serial_port_data(port);
627	/* drop dtr and rts */
628	spin_lock_irq(&priv->lock);
629	if (on == 0)
630		priv->line_control = 0;
631	else
632		priv->line_control = CONTROL_DTR | CONTROL_RTS;
633	priv->cmd_ctrl = 1;
634	spin_unlock_irq(&priv->lock);
635	cypress_write(NULL, port, NULL, 0);
636}
637
638static void cypress_close(struct usb_serial_port *port)
639{
640	struct cypress_private *priv = usb_get_serial_port_data(port);
641	unsigned long flags;
642
643	spin_lock_irqsave(&priv->lock, flags);
644	kfifo_reset_out(&priv->write_fifo);
645	spin_unlock_irqrestore(&priv->lock, flags);
646
647	dev_dbg(&port->dev, "%s - stopping urbs\n", __func__);
648	usb_kill_urb(port->interrupt_in_urb);
649	usb_kill_urb(port->interrupt_out_urb);
650
651	if (stats)
652		dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
653			priv->bytes_in, priv->bytes_out, priv->cmd_count);
654} /* cypress_close */
655
656
657static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
658					const unsigned char *buf, int count)
659{
660	struct cypress_private *priv = usb_get_serial_port_data(port);
661
662	dev_dbg(&port->dev, "%s - %d bytes\n", __func__, count);
663
664	/* line control commands, which need to be executed immediately,
665	   are not put into the buffer for obvious reasons.
666	 */
667	if (priv->cmd_ctrl) {
668		count = 0;
669		goto finish;
670	}
671
672	if (!count)
673		return count;
674
675	count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
676
677finish:
678	cypress_send(port);
679
680	return count;
681} /* cypress_write */
682
683
684static void cypress_send(struct usb_serial_port *port)
685{
686	int count = 0, result, offset, actual_size;
687	struct cypress_private *priv = usb_get_serial_port_data(port);
688	struct device *dev = &port->dev;
689	unsigned long flags;
690
691	if (!priv->comm_is_ok)
692		return;
693
694	dev_dbg(dev, "%s - interrupt out size is %d\n", __func__,
695		port->interrupt_out_size);
696
697	spin_lock_irqsave(&priv->lock, flags);
698	if (priv->write_urb_in_use) {
699		dev_dbg(dev, "%s - can't write, urb in use\n", __func__);
700		spin_unlock_irqrestore(&priv->lock, flags);
701		return;
702	}
703	spin_unlock_irqrestore(&priv->lock, flags);
704
705	/* clear buffer */
706	memset(port->interrupt_out_urb->transfer_buffer, 0,
707						port->interrupt_out_size);
708
709	spin_lock_irqsave(&priv->lock, flags);
710	switch (priv->pkt_fmt) {
711	default:
712	case packet_format_1:
713		/* this is for the CY7C64013... */
714		offset = 2;
715		port->interrupt_out_buffer[0] = priv->line_control;
716		break;
717	case packet_format_2:
718		/* this is for the CY7C63743... */
719		offset = 1;
720		port->interrupt_out_buffer[0] = priv->line_control;
721		break;
722	}
723
724	if (priv->line_control & CONTROL_RESET)
725		priv->line_control &= ~CONTROL_RESET;
726
727	if (priv->cmd_ctrl) {
728		priv->cmd_count++;
729		dev_dbg(dev, "%s - line control command being issued\n", __func__);
730		spin_unlock_irqrestore(&priv->lock, flags);
731		goto send;
732	} else
733		spin_unlock_irqrestore(&priv->lock, flags);
734
735	count = kfifo_out_locked(&priv->write_fifo,
736					&port->interrupt_out_buffer[offset],
737					port->interrupt_out_size - offset,
738					&priv->lock);
739	if (count == 0)
740		return;
741
742	switch (priv->pkt_fmt) {
743	default:
744	case packet_format_1:
745		port->interrupt_out_buffer[1] = count;
746		break;
747	case packet_format_2:
748		port->interrupt_out_buffer[0] |= count;
749	}
750
751	dev_dbg(dev, "%s - count is %d\n", __func__, count);
752
753send:
754	spin_lock_irqsave(&priv->lock, flags);
755	priv->write_urb_in_use = 1;
756	spin_unlock_irqrestore(&priv->lock, flags);
757
758	if (priv->cmd_ctrl)
759		actual_size = 1;
760	else
761		actual_size = count +
762			      (priv->pkt_fmt == packet_format_1 ? 2 : 1);
763
764	usb_serial_debug_data(dev, __func__, port->interrupt_out_size,
765			      port->interrupt_out_urb->transfer_buffer);
766
767	usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
768		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
769		port->interrupt_out_buffer, actual_size,
770		cypress_write_int_callback, port, priv->write_urb_interval);
771	result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
772	if (result) {
773		dev_err_console(port,
774				"%s - failed submitting write urb, error %d\n",
775							__func__, result);
776		priv->write_urb_in_use = 0;
777		cypress_set_dead(port);
778	}
779
780	spin_lock_irqsave(&priv->lock, flags);
781	if (priv->cmd_ctrl)
782		priv->cmd_ctrl = 0;
783
784	/* do not count the line control and size bytes */
785	priv->bytes_out += count;
786	spin_unlock_irqrestore(&priv->lock, flags);
787
788	usb_serial_port_softint(port);
789} /* cypress_send */
790
791
792/* returns how much space is available in the soft buffer */
793static unsigned int cypress_write_room(struct tty_struct *tty)
794{
795	struct usb_serial_port *port = tty->driver_data;
796	struct cypress_private *priv = usb_get_serial_port_data(port);
797	unsigned int room;
798	unsigned long flags;
799
800	spin_lock_irqsave(&priv->lock, flags);
801	room = kfifo_avail(&priv->write_fifo);
802	spin_unlock_irqrestore(&priv->lock, flags);
803
804	dev_dbg(&port->dev, "%s - returns %u\n", __func__, room);
805	return room;
806}
807
808
809static int cypress_tiocmget(struct tty_struct *tty)
810{
811	struct usb_serial_port *port = tty->driver_data;
812	struct cypress_private *priv = usb_get_serial_port_data(port);
813	__u8 status, control;
814	unsigned int result = 0;
815	unsigned long flags;
816
817	spin_lock_irqsave(&priv->lock, flags);
818	control = priv->line_control;
819	status = priv->current_status;
820	spin_unlock_irqrestore(&priv->lock, flags);
821
822	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
823		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
824		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
825		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
826		| ((status & UART_RI)         ? TIOCM_RI  : 0)
827		| ((status & UART_CD)         ? TIOCM_CD  : 0);
828
829	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
830
831	return result;
832}
833
834
835static int cypress_tiocmset(struct tty_struct *tty,
836			       unsigned int set, unsigned int clear)
837{
838	struct usb_serial_port *port = tty->driver_data;
839	struct cypress_private *priv = usb_get_serial_port_data(port);
840	unsigned long flags;
841
842	spin_lock_irqsave(&priv->lock, flags);
843	if (set & TIOCM_RTS)
844		priv->line_control |= CONTROL_RTS;
845	if (set & TIOCM_DTR)
846		priv->line_control |= CONTROL_DTR;
847	if (clear & TIOCM_RTS)
848		priv->line_control &= ~CONTROL_RTS;
849	if (clear & TIOCM_DTR)
850		priv->line_control &= ~CONTROL_DTR;
851	priv->cmd_ctrl = 1;
852	spin_unlock_irqrestore(&priv->lock, flags);
853
854	return cypress_write(tty, port, NULL, 0);
855}
856
857static void cypress_earthmate_init_termios(struct tty_struct *tty)
858{
859	tty_encode_baud_rate(tty, 4800, 4800);
860}
861
862static void cypress_set_termios(struct tty_struct *tty,
863				struct usb_serial_port *port,
864				const struct ktermios *old_termios)
865{
866	struct cypress_private *priv = usb_get_serial_port_data(port);
867	struct device *dev = &port->dev;
868	int data_bits, stop_bits, parity_type, parity_enable;
869	unsigned int cflag;
870	unsigned long flags;
871	__u8 oldlines;
872	int linechange = 0;
873
874	/* Unsupported features need clearing */
875	tty->termios.c_cflag &= ~(CMSPAR|CRTSCTS);
876
877	cflag = tty->termios.c_cflag;
878
879	/* set number of data bits, parity, stop bits */
880	/* when parity is disabled the parity type bit is ignored */
881
882	/* 1 means 2 stop bits, 0 means 1 stop bit */
883	stop_bits = cflag & CSTOPB ? 1 : 0;
884
885	if (cflag & PARENB) {
886		parity_enable = 1;
887		/* 1 means odd parity, 0 means even parity */
888		parity_type = cflag & PARODD ? 1 : 0;
889	} else
890		parity_enable = parity_type = 0;
891
892	data_bits = tty_get_char_size(cflag);
893
894	spin_lock_irqsave(&priv->lock, flags);
895	oldlines = priv->line_control;
896	if ((cflag & CBAUD) == B0) {
897		/* drop dtr and rts */
898		dev_dbg(dev, "%s - dropping the lines, baud rate 0bps\n", __func__);
899		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
900	} else
901		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
902	spin_unlock_irqrestore(&priv->lock, flags);
903
904	dev_dbg(dev, "%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)\n",
905		__func__, stop_bits, parity_enable, parity_type, data_bits);
906
907	cypress_serial_control(tty, port, tty_get_baud_rate(tty),
908			data_bits, stop_bits,
909			parity_enable, parity_type,
910			0, CYPRESS_SET_CONFIG);
911
912	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
913	 * filled into the private structure this should confirm that all is
914	 * working if it returns what we just set */
915	cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
916
917	/* Here we can define custom tty settings for devices; the main tty
918	 * termios flag base comes from empeg.c */
919
920	spin_lock_irqsave(&priv->lock, flags);
921	if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
922		dev_dbg(dev, "Using custom termios settings for a baud rate of 4800bps.\n");
923		/* define custom termios settings for NMEA protocol */
924
925		tty->termios.c_iflag /* input modes - */
926			&= ~(IGNBRK  /* disable ignore break */
927			| BRKINT     /* disable break causes interrupt */
928			| PARMRK     /* disable mark parity errors */
929			| ISTRIP     /* disable clear high bit of input char */
930			| INLCR      /* disable translate NL to CR */
931			| IGNCR      /* disable ignore CR */
932			| ICRNL      /* disable translate CR to NL */
933			| IXON);     /* disable enable XON/XOFF flow control */
934
935		tty->termios.c_oflag /* output modes */
936			&= ~OPOST;    /* disable postprocess output char */
937
938		tty->termios.c_lflag /* line discipline modes */
939			&= ~(ECHO     /* disable echo input characters */
940			| ECHONL      /* disable echo new line */
941			| ICANON      /* disable erase, kill, werase, and rprnt
942					 special characters */
943			| ISIG        /* disable interrupt, quit, and suspend
944					 special characters */
945			| IEXTEN);    /* disable non-POSIX special characters */
946	} /* CT_CYPHIDCOM: Application should handle this for device */
947
948	linechange = (priv->line_control != oldlines);
949	spin_unlock_irqrestore(&priv->lock, flags);
950
951	/* if necessary, set lines */
952	if (linechange) {
953		priv->cmd_ctrl = 1;
954		cypress_write(tty, port, NULL, 0);
955	}
956} /* cypress_set_termios */
957
958
959/* returns amount of data still left in soft buffer */
960static unsigned int cypress_chars_in_buffer(struct tty_struct *tty)
961{
962	struct usb_serial_port *port = tty->driver_data;
963	struct cypress_private *priv = usb_get_serial_port_data(port);
964	unsigned int chars;
965	unsigned long flags;
966
967	spin_lock_irqsave(&priv->lock, flags);
968	chars = kfifo_len(&priv->write_fifo);
969	spin_unlock_irqrestore(&priv->lock, flags);
970
971	dev_dbg(&port->dev, "%s - returns %u\n", __func__, chars);
972	return chars;
973}
974
975
976static void cypress_throttle(struct tty_struct *tty)
977{
978	struct usb_serial_port *port = tty->driver_data;
979	struct cypress_private *priv = usb_get_serial_port_data(port);
980
981	spin_lock_irq(&priv->lock);
982	priv->rx_flags = THROTTLED;
983	spin_unlock_irq(&priv->lock);
984}
985
986
987static void cypress_unthrottle(struct tty_struct *tty)
988{
989	struct usb_serial_port *port = tty->driver_data;
990	struct cypress_private *priv = usb_get_serial_port_data(port);
991	int actually_throttled, result;
992
993	spin_lock_irq(&priv->lock);
994	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
995	priv->rx_flags = 0;
996	spin_unlock_irq(&priv->lock);
997
998	if (!priv->comm_is_ok)
999		return;
1000
1001	if (actually_throttled) {
1002		result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
1003		if (result) {
1004			dev_err(&port->dev, "%s - failed submitting read urb, "
1005					"error %d\n", __func__, result);
1006			cypress_set_dead(port);
1007		}
1008	}
1009}
1010
1011
1012static void cypress_read_int_callback(struct urb *urb)
1013{
1014	struct usb_serial_port *port = urb->context;
1015	struct cypress_private *priv = usb_get_serial_port_data(port);
1016	struct device *dev = &urb->dev->dev;
1017	struct tty_struct *tty;
1018	unsigned char *data = urb->transfer_buffer;
1019	unsigned long flags;
1020	char tty_flag = TTY_NORMAL;
1021	int bytes = 0;
1022	int result;
1023	int i = 0;
1024	int status = urb->status;
1025
1026	switch (status) {
1027	case 0: /* success */
1028		break;
1029	case -ECONNRESET:
1030	case -ENOENT:
1031	case -ESHUTDOWN:
1032		/* precursor to disconnect so just go away */
1033		return;
1034	case -EPIPE:
1035		/* Can't call usb_clear_halt while in_interrupt */
1036		fallthrough;
1037	default:
1038		/* something ugly is going on... */
1039		dev_err(dev, "%s - unexpected nonzero read status received: %d\n",
1040			__func__, status);
1041		cypress_set_dead(port);
1042		return;
1043	}
1044
1045	spin_lock_irqsave(&priv->lock, flags);
1046	if (priv->rx_flags & THROTTLED) {
1047		dev_dbg(dev, "%s - now throttling\n", __func__);
1048		priv->rx_flags |= ACTUALLY_THROTTLED;
1049		spin_unlock_irqrestore(&priv->lock, flags);
1050		return;
1051	}
1052	spin_unlock_irqrestore(&priv->lock, flags);
1053
1054	tty = tty_port_tty_get(&port->port);
1055	if (!tty) {
1056		dev_dbg(dev, "%s - bad tty pointer - exiting\n", __func__);
1057		return;
1058	}
1059
1060	spin_lock_irqsave(&priv->lock, flags);
1061	result = urb->actual_length;
1062	switch (priv->pkt_fmt) {
1063	default:
1064	case packet_format_1:
1065		/* This is for the CY7C64013... */
1066		priv->current_status = data[0] & 0xF8;
1067		bytes = data[1] + 2;
1068		i = 2;
1069		break;
1070	case packet_format_2:
1071		/* This is for the CY7C63743... */
1072		priv->current_status = data[0] & 0xF8;
1073		bytes = (data[0] & 0x07) + 1;
1074		i = 1;
1075		break;
1076	}
1077	spin_unlock_irqrestore(&priv->lock, flags);
1078	if (result < bytes) {
1079		dev_dbg(dev,
1080			"%s - wrong packet size - received %d bytes but packet said %d bytes\n",
1081			__func__, result, bytes);
1082		goto continue_read;
1083	}
1084
1085	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
1086
1087	spin_lock_irqsave(&priv->lock, flags);
1088	/* check to see if status has changed */
1089	if (priv->current_status != priv->prev_status) {
1090		u8 delta = priv->current_status ^ priv->prev_status;
1091
1092		if (delta & UART_MSR_MASK) {
1093			if (delta & UART_CTS)
1094				port->icount.cts++;
1095			if (delta & UART_DSR)
1096				port->icount.dsr++;
1097			if (delta & UART_RI)
1098				port->icount.rng++;
1099			if (delta & UART_CD)
1100				port->icount.dcd++;
1101
1102			wake_up_interruptible(&port->port.delta_msr_wait);
1103		}
1104
1105		priv->prev_status = priv->current_status;
1106	}
1107	spin_unlock_irqrestore(&priv->lock, flags);
1108
1109	/* hangup, as defined in acm.c... this might be a bad place for it
1110	 * though */
1111	if (tty && !C_CLOCAL(tty) && !(priv->current_status & UART_CD)) {
1112		dev_dbg(dev, "%s - calling hangup\n", __func__);
1113		tty_hangup(tty);
1114		goto continue_read;
1115	}
1116
1117	/* There is one error bit... I'm assuming it is a parity error
1118	 * indicator as the generic firmware will set this bit to 1 if a
1119	 * parity error occurs.
1120	 * I can not find reference to any other error events. */
1121	spin_lock_irqsave(&priv->lock, flags);
1122	if (priv->current_status & CYP_ERROR) {
1123		spin_unlock_irqrestore(&priv->lock, flags);
1124		tty_flag = TTY_PARITY;
1125		dev_dbg(dev, "%s - Parity Error detected\n", __func__);
1126	} else
1127		spin_unlock_irqrestore(&priv->lock, flags);
1128
1129	/* process read if there is data other than line status */
1130	if (bytes > i) {
1131		tty_insert_flip_string_fixed_flag(&port->port, data + i,
1132				tty_flag, bytes - i);
1133		tty_flip_buffer_push(&port->port);
1134	}
1135
1136	spin_lock_irqsave(&priv->lock, flags);
1137	/* control and status byte(s) are also counted */
1138	priv->bytes_in += bytes;
1139	spin_unlock_irqrestore(&priv->lock, flags);
1140
1141continue_read:
1142	tty_kref_put(tty);
1143
1144	/* Continue trying to always read */
1145
1146	if (priv->comm_is_ok) {
1147		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1148				usb_rcvintpipe(port->serial->dev,
1149					port->interrupt_in_endpointAddress),
1150				port->interrupt_in_urb->transfer_buffer,
1151				port->interrupt_in_urb->transfer_buffer_length,
1152				cypress_read_int_callback, port,
1153				priv->read_urb_interval);
1154		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1155		if (result && result != -EPERM) {
1156			dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
1157				__func__, result);
1158			cypress_set_dead(port);
1159		}
1160	}
1161} /* cypress_read_int_callback */
1162
1163
1164static void cypress_write_int_callback(struct urb *urb)
1165{
1166	struct usb_serial_port *port = urb->context;
1167	struct cypress_private *priv = usb_get_serial_port_data(port);
1168	struct device *dev = &urb->dev->dev;
1169	int status = urb->status;
1170
1171	switch (status) {
1172	case 0:
1173		/* success */
1174		break;
1175	case -ECONNRESET:
1176	case -ENOENT:
1177	case -ESHUTDOWN:
1178		/* this urb is terminated, clean up */
1179		dev_dbg(dev, "%s - urb shutting down with status: %d\n",
1180			__func__, status);
1181		priv->write_urb_in_use = 0;
1182		return;
1183	case -EPIPE:
1184		/* Cannot call usb_clear_halt while in_interrupt */
1185		fallthrough;
1186	default:
1187		dev_err(dev, "%s - unexpected nonzero write status received: %d\n",
1188			__func__, status);
1189		cypress_set_dead(port);
1190		break;
1191	}
1192	priv->write_urb_in_use = 0;
1193
1194	/* send any buffered data */
1195	cypress_send(port);
1196}
1197
1198module_usb_serial_driver(serial_drivers, id_table_combined);
1199
1200MODULE_AUTHOR(DRIVER_AUTHOR);
1201MODULE_DESCRIPTION(DRIVER_DESC);
1202MODULE_LICENSE("GPL");
1203
1204module_param(stats, bool, 0644);
1205MODULE_PARM_DESC(stats, "Enable statistics or not");
1206module_param(interval, int, 0644);
1207MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1208module_param(unstable_bauds, bool, 0644);
1209MODULE_PARM_DESC(unstable_bauds, "Allow unstable baud rates");
1210