1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * KLSI KL5KUSB105 chip RS232 converter driver
4 *
5 *   Copyright (C) 2010 Johan Hovold <jhovold@gmail.com>
6 *   Copyright (C) 2001 Utz-Uwe Haus <haus@uuhaus.de>
7 *
8 * All information about the device was acquired using SniffUSB ans snoopUSB
9 * on Windows98.
10 * It was written out of frustration with the PalmConnect USB Serial adapter
11 * sold by Palm Inc.
12 * Neither Palm, nor their contractor (MCCI) or their supplier (KLSI) provided
13 * information that was not already available.
14 *
15 * It seems that KLSI bought some silicon-design information from ScanLogic,
16 * whose SL11R processor is at the core of the KL5KUSB chipset from KLSI.
17 * KLSI has firmware available for their devices; it is probable that the
18 * firmware differs from that used by KLSI in their products. If you have an
19 * original KLSI device and can provide some information on it, I would be
20 * most interested in adding support for it here. If you have any information
21 * on the protocol used (or find errors in my reverse-engineered stuff), please
22 * let me know.
23 *
24 * The code was only tested with a PalmConnect USB adapter; if you
25 * are adventurous, try it with any KLSI-based device and let me know how it
26 * breaks so that I can fix it!
27 */
28
29/* TODO:
30 *	check modem line signals
31 *	implement handshaking or decide that we do not support it
32 */
33
34#include <linux/kernel.h>
35#include <linux/errno.h>
36#include <linux/slab.h>
37#include <linux/tty.h>
38#include <linux/tty_driver.h>
39#include <linux/tty_flip.h>
40#include <linux/module.h>
41#include <linux/uaccess.h>
42#include <asm/unaligned.h>
43#include <linux/usb.h>
44#include <linux/usb/serial.h>
45#include "kl5kusb105.h"
46
47#define DRIVER_AUTHOR "Utz-Uwe Haus <haus@uuhaus.de>, Johan Hovold <jhovold@gmail.com>"
48#define DRIVER_DESC "KLSI KL5KUSB105 chipset USB->Serial Converter driver"
49
50
51/*
52 * Function prototypes
53 */
54static int klsi_105_port_probe(struct usb_serial_port *port);
55static int klsi_105_port_remove(struct usb_serial_port *port);
56static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port);
57static void klsi_105_close(struct usb_serial_port *port);
58static void klsi_105_set_termios(struct tty_struct *tty,
59			struct usb_serial_port *port, struct ktermios *old);
60static int  klsi_105_tiocmget(struct tty_struct *tty);
61static void klsi_105_process_read_urb(struct urb *urb);
62static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
63						void *dest, size_t size);
64
65/*
66 * All of the device info needed for the KLSI converters.
67 */
68static const struct usb_device_id id_table[] = {
69	{ USB_DEVICE(PALMCONNECT_VID, PALMCONNECT_PID) },
70	{ }		/* Terminating entry */
71};
72
73MODULE_DEVICE_TABLE(usb, id_table);
74
75static struct usb_serial_driver kl5kusb105d_device = {
76	.driver = {
77		.owner =	THIS_MODULE,
78		.name =		"kl5kusb105d",
79	},
80	.description =		"KL5KUSB105D / PalmConnect",
81	.id_table =		id_table,
82	.num_ports =		1,
83	.bulk_out_size =	64,
84	.open =			klsi_105_open,
85	.close =		klsi_105_close,
86	.set_termios =		klsi_105_set_termios,
87	.tiocmget =		klsi_105_tiocmget,
88	.port_probe =		klsi_105_port_probe,
89	.port_remove =		klsi_105_port_remove,
90	.throttle =		usb_serial_generic_throttle,
91	.unthrottle =		usb_serial_generic_unthrottle,
92	.process_read_urb =	klsi_105_process_read_urb,
93	.prepare_write_buffer =	klsi_105_prepare_write_buffer,
94};
95
96static struct usb_serial_driver * const serial_drivers[] = {
97	&kl5kusb105d_device, NULL
98};
99
100struct klsi_105_port_settings {
101	u8	pktlen;		/* always 5, it seems */
102	u8	baudrate;
103	u8	databits;
104	u8	unknown1;
105	u8	unknown2;
106};
107
108struct klsi_105_private {
109	struct klsi_105_port_settings	cfg;
110	unsigned long			line_state; /* modem line settings */
111	spinlock_t			lock;
112};
113
114
115/*
116 * Handle vendor specific USB requests
117 */
118
119
120#define KLSI_TIMEOUT	 5000 /* default urb timeout */
121
122static int klsi_105_chg_port_settings(struct usb_serial_port *port,
123				      struct klsi_105_port_settings *settings)
124{
125	int rc;
126
127	rc = usb_control_msg(port->serial->dev,
128			usb_sndctrlpipe(port->serial->dev, 0),
129			KL5KUSB105A_SIO_SET_DATA,
130			USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_INTERFACE,
131			0, /* value */
132			0, /* index */
133			settings,
134			sizeof(struct klsi_105_port_settings),
135			KLSI_TIMEOUT);
136	if (rc < 0)
137		dev_err(&port->dev,
138			"Change port settings failed (error = %d)\n", rc);
139
140	dev_dbg(&port->dev,
141		"pktlen %u, baudrate 0x%02x, databits %u, u1 %u, u2 %u\n",
142		settings->pktlen, settings->baudrate, settings->databits,
143		settings->unknown1, settings->unknown2);
144
145	return rc;
146}
147
148/* translate a 16-bit status value from the device to linux's TIO bits */
149static unsigned long klsi_105_status2linestate(const __u16 status)
150{
151	unsigned long res = 0;
152
153	res =   ((status & KL5KUSB105A_DSR) ? TIOCM_DSR : 0)
154	      | ((status & KL5KUSB105A_CTS) ? TIOCM_CTS : 0)
155	      ;
156
157	return res;
158}
159
160/*
161 * Read line control via vendor command and return result through
162 * *line_state_p
163 */
164/* It seems that the status buffer has always only 2 bytes length */
165#define KLSI_STATUSBUF_LEN	2
166static int klsi_105_get_line_state(struct usb_serial_port *port,
167				   unsigned long *line_state_p)
168{
169	int rc;
170	u8 *status_buf;
171	__u16 status;
172
173	status_buf = kmalloc(KLSI_STATUSBUF_LEN, GFP_KERNEL);
174	if (!status_buf)
175		return -ENOMEM;
176
177	status_buf[0] = 0xff;
178	status_buf[1] = 0xff;
179	rc = usb_control_msg(port->serial->dev,
180			     usb_rcvctrlpipe(port->serial->dev, 0),
181			     KL5KUSB105A_SIO_POLL,
182			     USB_TYPE_VENDOR | USB_DIR_IN,
183			     0, /* value */
184			     0, /* index */
185			     status_buf, KLSI_STATUSBUF_LEN,
186			     10000
187			     );
188	if (rc != KLSI_STATUSBUF_LEN) {
189		dev_err(&port->dev, "reading line status failed: %d\n", rc);
190		if (rc >= 0)
191			rc = -EIO;
192	} else {
193		status = get_unaligned_le16(status_buf);
194
195		dev_dbg(&port->dev, "read status %02x %02x\n",
196			status_buf[0], status_buf[1]);
197
198		*line_state_p = klsi_105_status2linestate(status);
199	}
200
201	kfree(status_buf);
202	return rc;
203}
204
205
206/*
207 * Driver's tty interface functions
208 */
209
210static int klsi_105_port_probe(struct usb_serial_port *port)
211{
212	struct klsi_105_private *priv;
213
214	priv = kmalloc(sizeof(*priv), GFP_KERNEL);
215	if (!priv)
216		return -ENOMEM;
217
218	/* set initial values for control structures */
219	priv->cfg.pktlen    = 5;
220	priv->cfg.baudrate  = kl5kusb105a_sio_b9600;
221	priv->cfg.databits  = kl5kusb105a_dtb_8;
222	priv->cfg.unknown1  = 0;
223	priv->cfg.unknown2  = 1;
224
225	priv->line_state    = 0;
226
227	spin_lock_init(&priv->lock);
228
229	usb_set_serial_port_data(port, priv);
230
231	return 0;
232}
233
234static int klsi_105_port_remove(struct usb_serial_port *port)
235{
236	struct klsi_105_private *priv;
237
238	priv = usb_get_serial_port_data(port);
239	kfree(priv);
240
241	return 0;
242}
243
244static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
245{
246	struct klsi_105_private *priv = usb_get_serial_port_data(port);
247	int retval = 0;
248	int rc;
249	unsigned long line_state;
250	struct klsi_105_port_settings *cfg;
251	unsigned long flags;
252
253	/* Do a defined restart:
254	 * Set up sane default baud rate and send the 'READ_ON'
255	 * vendor command.
256	 * FIXME: set modem line control (how?)
257	 * Then read the modem line control and store values in
258	 * priv->line_state.
259	 */
260	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
261	if (!cfg)
262		return -ENOMEM;
263
264	cfg->pktlen   = 5;
265	cfg->baudrate = kl5kusb105a_sio_b9600;
266	cfg->databits = kl5kusb105a_dtb_8;
267	cfg->unknown1 = 0;
268	cfg->unknown2 = 1;
269	klsi_105_chg_port_settings(port, cfg);
270
271	spin_lock_irqsave(&priv->lock, flags);
272	priv->cfg.pktlen   = cfg->pktlen;
273	priv->cfg.baudrate = cfg->baudrate;
274	priv->cfg.databits = cfg->databits;
275	priv->cfg.unknown1 = cfg->unknown1;
276	priv->cfg.unknown2 = cfg->unknown2;
277	spin_unlock_irqrestore(&priv->lock, flags);
278
279	kfree(cfg);
280
281	/* READ_ON and urb submission */
282	rc = usb_serial_generic_open(tty, port);
283	if (rc)
284		return rc;
285
286	rc = usb_control_msg(port->serial->dev,
287			     usb_sndctrlpipe(port->serial->dev, 0),
288			     KL5KUSB105A_SIO_CONFIGURE,
289			     USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_INTERFACE,
290			     KL5KUSB105A_SIO_CONFIGURE_READ_ON,
291			     0, /* index */
292			     NULL,
293			     0,
294			     KLSI_TIMEOUT);
295	if (rc < 0) {
296		dev_err(&port->dev, "Enabling read failed (error = %d)\n", rc);
297		retval = rc;
298		goto err_generic_close;
299	} else
300		dev_dbg(&port->dev, "%s - enabled reading\n", __func__);
301
302	rc = klsi_105_get_line_state(port, &line_state);
303	if (rc < 0) {
304		retval = rc;
305		goto err_disable_read;
306	}
307
308	spin_lock_irqsave(&priv->lock, flags);
309	priv->line_state = line_state;
310	spin_unlock_irqrestore(&priv->lock, flags);
311	dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__,
312			line_state);
313
314	return 0;
315
316err_disable_read:
317	usb_control_msg(port->serial->dev,
318			     usb_sndctrlpipe(port->serial->dev, 0),
319			     KL5KUSB105A_SIO_CONFIGURE,
320			     USB_TYPE_VENDOR | USB_DIR_OUT,
321			     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
322			     0, /* index */
323			     NULL, 0,
324			     KLSI_TIMEOUT);
325err_generic_close:
326	usb_serial_generic_close(port);
327
328	return retval;
329}
330
331static void klsi_105_close(struct usb_serial_port *port)
332{
333	int rc;
334
335	/* send READ_OFF */
336	rc = usb_control_msg(port->serial->dev,
337			     usb_sndctrlpipe(port->serial->dev, 0),
338			     KL5KUSB105A_SIO_CONFIGURE,
339			     USB_TYPE_VENDOR | USB_DIR_OUT,
340			     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
341			     0, /* index */
342			     NULL, 0,
343			     KLSI_TIMEOUT);
344	if (rc < 0)
345		dev_err(&port->dev, "failed to disable read: %d\n", rc);
346
347	/* shutdown our bulk reads and writes */
348	usb_serial_generic_close(port);
349}
350
351/* We need to write a complete 64-byte data block and encode the
352 * number actually sent in the first double-byte, LSB-order. That
353 * leaves at most 62 bytes of payload.
354 */
355#define KLSI_HDR_LEN		2
356static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
357						void *dest, size_t size)
358{
359	unsigned char *buf = dest;
360	int count;
361
362	count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size,
363								&port->lock);
364	put_unaligned_le16(count, buf);
365
366	return count + KLSI_HDR_LEN;
367}
368
369/* The data received is preceded by a length double-byte in LSB-first order.
370 */
371static void klsi_105_process_read_urb(struct urb *urb)
372{
373	struct usb_serial_port *port = urb->context;
374	unsigned char *data = urb->transfer_buffer;
375	unsigned len;
376
377	/* empty urbs seem to happen, we ignore them */
378	if (!urb->actual_length)
379		return;
380
381	if (urb->actual_length <= KLSI_HDR_LEN) {
382		dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
383		return;
384	}
385
386	len = get_unaligned_le16(data);
387	if (len > urb->actual_length - KLSI_HDR_LEN) {
388		dev_dbg(&port->dev, "%s - packet length mismatch\n", __func__);
389		len = urb->actual_length - KLSI_HDR_LEN;
390	}
391
392	tty_insert_flip_string(&port->port, data + KLSI_HDR_LEN, len);
393	tty_flip_buffer_push(&port->port);
394}
395
396static void klsi_105_set_termios(struct tty_struct *tty,
397				 struct usb_serial_port *port,
398				 struct ktermios *old_termios)
399{
400	struct klsi_105_private *priv = usb_get_serial_port_data(port);
401	struct device *dev = &port->dev;
402	unsigned int iflag = tty->termios.c_iflag;
403	unsigned int old_iflag = old_termios->c_iflag;
404	unsigned int cflag = tty->termios.c_cflag;
405	unsigned int old_cflag = old_termios->c_cflag;
406	struct klsi_105_port_settings *cfg;
407	unsigned long flags;
408	speed_t baud;
409
410	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
411	if (!cfg)
412		return;
413
414	/* lock while we are modifying the settings */
415	spin_lock_irqsave(&priv->lock, flags);
416
417	/*
418	 * Update baud rate
419	 */
420	baud = tty_get_baud_rate(tty);
421
422	switch (baud) {
423	case 0: /* handled below */
424		break;
425	case 1200:
426		priv->cfg.baudrate = kl5kusb105a_sio_b1200;
427		break;
428	case 2400:
429		priv->cfg.baudrate = kl5kusb105a_sio_b2400;
430		break;
431	case 4800:
432		priv->cfg.baudrate = kl5kusb105a_sio_b4800;
433		break;
434	case 9600:
435		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
436		break;
437	case 19200:
438		priv->cfg.baudrate = kl5kusb105a_sio_b19200;
439		break;
440	case 38400:
441		priv->cfg.baudrate = kl5kusb105a_sio_b38400;
442		break;
443	case 57600:
444		priv->cfg.baudrate = kl5kusb105a_sio_b57600;
445		break;
446	case 115200:
447		priv->cfg.baudrate = kl5kusb105a_sio_b115200;
448		break;
449	default:
450		dev_dbg(dev, "unsupported baudrate, using 9600\n");
451		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
452		baud = 9600;
453		break;
454	}
455
456	/*
457	 * FIXME: implement B0 handling
458	 *
459	 * Maybe this should be simulated by sending read disable and read
460	 * enable messages?
461	 */
462
463	tty_encode_baud_rate(tty, baud, baud);
464
465	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
466		/* set the number of data bits */
467		switch (cflag & CSIZE) {
468		case CS5:
469			dev_dbg(dev, "%s - 5 bits/byte not supported\n", __func__);
470			spin_unlock_irqrestore(&priv->lock, flags);
471			goto err;
472		case CS6:
473			dev_dbg(dev, "%s - 6 bits/byte not supported\n", __func__);
474			spin_unlock_irqrestore(&priv->lock, flags);
475			goto err;
476		case CS7:
477			priv->cfg.databits = kl5kusb105a_dtb_7;
478			break;
479		case CS8:
480			priv->cfg.databits = kl5kusb105a_dtb_8;
481			break;
482		default:
483			dev_err(dev, "CSIZE was not CS5-CS8, using default of 8\n");
484			priv->cfg.databits = kl5kusb105a_dtb_8;
485			break;
486		}
487	}
488
489	/*
490	 * Update line control register (LCR)
491	 */
492	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
493	    || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
494		/* Not currently supported */
495		tty->termios.c_cflag &= ~(PARENB|PARODD|CSTOPB);
496	}
497	/*
498	 * Set flow control: well, I do not really now how to handle DTR/RTS.
499	 * Just do what we have seen with SniffUSB on Win98.
500	 */
501	if ((iflag & IXOFF) != (old_iflag & IXOFF)
502	    || (iflag & IXON) != (old_iflag & IXON)
503	    ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
504		/* Not currently supported */
505		tty->termios.c_cflag &= ~CRTSCTS;
506	}
507	memcpy(cfg, &priv->cfg, sizeof(*cfg));
508	spin_unlock_irqrestore(&priv->lock, flags);
509
510	/* now commit changes to device */
511	klsi_105_chg_port_settings(port, cfg);
512err:
513	kfree(cfg);
514}
515
516static int klsi_105_tiocmget(struct tty_struct *tty)
517{
518	struct usb_serial_port *port = tty->driver_data;
519	struct klsi_105_private *priv = usb_get_serial_port_data(port);
520	unsigned long flags;
521	int rc;
522	unsigned long line_state;
523
524	rc = klsi_105_get_line_state(port, &line_state);
525	if (rc < 0) {
526		dev_err(&port->dev,
527			"Reading line control failed (error = %d)\n", rc);
528		/* better return value? EAGAIN? */
529		return rc;
530	}
531
532	spin_lock_irqsave(&priv->lock, flags);
533	priv->line_state = line_state;
534	spin_unlock_irqrestore(&priv->lock, flags);
535	dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
536	return (int)line_state;
537}
538
539module_usb_serial_driver(serial_drivers, id_table);
540
541MODULE_AUTHOR(DRIVER_AUTHOR);
542MODULE_DESCRIPTION(DRIVER_DESC);
543MODULE_LICENSE("GPL");
544