xref: /linux/drivers/usb/serial/kl5kusb105.c (revision 7fc7f25419f5a6b09199ba4b5026b94ef184fa79)
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  */
54 static int klsi_105_port_probe(struct usb_serial_port *port);
55 static void klsi_105_port_remove(struct usb_serial_port *port);
56 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port);
57 static void klsi_105_close(struct usb_serial_port *port);
58 static void klsi_105_set_termios(struct tty_struct *tty,
59 				 struct usb_serial_port *port,
60 				 const struct ktermios *old_termios);
61 static int  klsi_105_tiocmget(struct tty_struct *tty);
62 static void klsi_105_process_read_urb(struct urb *urb);
63 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
64 						void *dest, size_t size);
65 
66 /*
67  * All of the device info needed for the KLSI converters.
68  */
69 static const struct usb_device_id id_table[] = {
70 	{ USB_DEVICE(PALMCONNECT_VID, PALMCONNECT_PID) },
71 	{ }		/* Terminating entry */
72 };
73 
74 MODULE_DEVICE_TABLE(usb, id_table);
75 
76 static struct usb_serial_driver kl5kusb105d_device = {
77 	.driver = {
78 		.owner =	THIS_MODULE,
79 		.name =		"kl5kusb105d",
80 	},
81 	.description =		"KL5KUSB105D / PalmConnect",
82 	.id_table =		id_table,
83 	.num_ports =		1,
84 	.bulk_out_size =	64,
85 	.open =			klsi_105_open,
86 	.close =		klsi_105_close,
87 	.set_termios =		klsi_105_set_termios,
88 	.tiocmget =		klsi_105_tiocmget,
89 	.port_probe =		klsi_105_port_probe,
90 	.port_remove =		klsi_105_port_remove,
91 	.throttle =		usb_serial_generic_throttle,
92 	.unthrottle =		usb_serial_generic_unthrottle,
93 	.process_read_urb =	klsi_105_process_read_urb,
94 	.prepare_write_buffer =	klsi_105_prepare_write_buffer,
95 };
96 
97 static struct usb_serial_driver * const serial_drivers[] = {
98 	&kl5kusb105d_device, NULL
99 };
100 
101 struct klsi_105_port_settings {
102 	u8	pktlen;		/* always 5, it seems */
103 	u8	baudrate;
104 	u8	databits;
105 	u8	unknown1;
106 	u8	unknown2;
107 };
108 
109 struct klsi_105_private {
110 	struct klsi_105_port_settings	cfg;
111 	unsigned long			line_state; /* modem line settings */
112 	spinlock_t			lock;
113 };
114 
115 
116 /*
117  * Handle vendor specific USB requests
118  */
119 
120 
121 #define KLSI_TIMEOUT	 5000 /* default urb timeout */
122 
123 static int klsi_105_chg_port_settings(struct usb_serial_port *port,
124 				      struct klsi_105_port_settings *settings)
125 {
126 	int rc;
127 
128 	rc = usb_control_msg_send(port->serial->dev,
129 				  0,
130 				  KL5KUSB105A_SIO_SET_DATA,
131 				  USB_TYPE_VENDOR | USB_DIR_OUT |
132 				  USB_RECIP_INTERFACE,
133 				  0, /* value */
134 				  0, /* index */
135 				  settings,
136 				  sizeof(struct klsi_105_port_settings),
137 				  KLSI_TIMEOUT,
138 				  GFP_KERNEL);
139 	if (rc)
140 		dev_err(&port->dev,
141 			"Change port settings failed (error = %d)\n", rc);
142 
143 	dev_dbg(&port->dev,
144 		"pktlen %u, baudrate 0x%02x, databits %u, u1 %u, u2 %u\n",
145 		settings->pktlen, settings->baudrate, settings->databits,
146 		settings->unknown1, settings->unknown2);
147 
148 	return rc;
149 }
150 
151 /*
152  * Read line control via vendor command and return result through
153  * the state pointer.
154  */
155 static int klsi_105_get_line_state(struct usb_serial_port *port,
156 				   unsigned long *state)
157 {
158 	u16 status;
159 	int rc;
160 
161 	rc = usb_control_msg_recv(port->serial->dev, 0,
162 				  KL5KUSB105A_SIO_POLL,
163 				  USB_TYPE_VENDOR | USB_DIR_IN,
164 				  0, /* value */
165 				  0, /* index */
166 				  &status, sizeof(status),
167 				  10000,
168 				  GFP_KERNEL);
169 	if (rc) {
170 		dev_err(&port->dev, "reading line status failed: %d\n", rc);
171 		return rc;
172 	}
173 
174 	le16_to_cpus(&status);
175 
176 	dev_dbg(&port->dev, "read status %04x\n", status);
177 
178 	*state = ((status & KL5KUSB105A_DSR) ? TIOCM_DSR : 0) |
179 		 ((status & KL5KUSB105A_CTS) ? TIOCM_CTS : 0);
180 
181 	return 0;
182 }
183 
184 
185 /*
186  * Driver's tty interface functions
187  */
188 
189 static int klsi_105_port_probe(struct usb_serial_port *port)
190 {
191 	struct klsi_105_private *priv;
192 
193 	priv = kmalloc(sizeof(*priv), GFP_KERNEL);
194 	if (!priv)
195 		return -ENOMEM;
196 
197 	/* set initial values for control structures */
198 	priv->cfg.pktlen    = 5;
199 	priv->cfg.baudrate  = kl5kusb105a_sio_b9600;
200 	priv->cfg.databits  = kl5kusb105a_dtb_8;
201 	priv->cfg.unknown1  = 0;
202 	priv->cfg.unknown2  = 1;
203 
204 	priv->line_state    = 0;
205 
206 	spin_lock_init(&priv->lock);
207 
208 	usb_set_serial_port_data(port, priv);
209 
210 	return 0;
211 }
212 
213 static void klsi_105_port_remove(struct usb_serial_port *port)
214 {
215 	struct klsi_105_private *priv;
216 
217 	priv = usb_get_serial_port_data(port);
218 	kfree(priv);
219 }
220 
221 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
222 {
223 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
224 	int retval = 0;
225 	int rc;
226 	unsigned long line_state;
227 	struct klsi_105_port_settings cfg;
228 	unsigned long flags;
229 
230 	/* Do a defined restart:
231 	 * Set up sane default baud rate and send the 'READ_ON'
232 	 * vendor command.
233 	 * FIXME: set modem line control (how?)
234 	 * Then read the modem line control and store values in
235 	 * priv->line_state.
236 	 */
237 
238 	cfg.pktlen   = 5;
239 	cfg.baudrate = kl5kusb105a_sio_b9600;
240 	cfg.databits = kl5kusb105a_dtb_8;
241 	cfg.unknown1 = 0;
242 	cfg.unknown2 = 1;
243 	klsi_105_chg_port_settings(port, &cfg);
244 
245 	spin_lock_irqsave(&priv->lock, flags);
246 	priv->cfg.pktlen   = cfg.pktlen;
247 	priv->cfg.baudrate = cfg.baudrate;
248 	priv->cfg.databits = cfg.databits;
249 	priv->cfg.unknown1 = cfg.unknown1;
250 	priv->cfg.unknown2 = cfg.unknown2;
251 	spin_unlock_irqrestore(&priv->lock, flags);
252 
253 	/* READ_ON and urb submission */
254 	rc = usb_serial_generic_open(tty, port);
255 	if (rc)
256 		return rc;
257 
258 	rc = usb_control_msg(port->serial->dev,
259 			     usb_sndctrlpipe(port->serial->dev, 0),
260 			     KL5KUSB105A_SIO_CONFIGURE,
261 			     USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_INTERFACE,
262 			     KL5KUSB105A_SIO_CONFIGURE_READ_ON,
263 			     0, /* index */
264 			     NULL,
265 			     0,
266 			     KLSI_TIMEOUT);
267 	if (rc < 0) {
268 		dev_err(&port->dev, "Enabling read failed (error = %d)\n", rc);
269 		retval = rc;
270 		goto err_generic_close;
271 	} else
272 		dev_dbg(&port->dev, "%s - enabled reading\n", __func__);
273 
274 	rc = klsi_105_get_line_state(port, &line_state);
275 	if (rc < 0) {
276 		retval = rc;
277 		goto err_disable_read;
278 	}
279 
280 	spin_lock_irqsave(&priv->lock, flags);
281 	priv->line_state = line_state;
282 	spin_unlock_irqrestore(&priv->lock, flags);
283 	dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__,
284 			line_state);
285 
286 	return 0;
287 
288 err_disable_read:
289 	usb_control_msg(port->serial->dev,
290 			     usb_sndctrlpipe(port->serial->dev, 0),
291 			     KL5KUSB105A_SIO_CONFIGURE,
292 			     USB_TYPE_VENDOR | USB_DIR_OUT,
293 			     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
294 			     0, /* index */
295 			     NULL, 0,
296 			     KLSI_TIMEOUT);
297 err_generic_close:
298 	usb_serial_generic_close(port);
299 
300 	return retval;
301 }
302 
303 static void klsi_105_close(struct usb_serial_port *port)
304 {
305 	int rc;
306 
307 	/* send READ_OFF */
308 	rc = usb_control_msg(port->serial->dev,
309 			     usb_sndctrlpipe(port->serial->dev, 0),
310 			     KL5KUSB105A_SIO_CONFIGURE,
311 			     USB_TYPE_VENDOR | USB_DIR_OUT,
312 			     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
313 			     0, /* index */
314 			     NULL, 0,
315 			     KLSI_TIMEOUT);
316 	if (rc < 0)
317 		dev_err(&port->dev, "failed to disable read: %d\n", rc);
318 
319 	/* shutdown our bulk reads and writes */
320 	usb_serial_generic_close(port);
321 }
322 
323 /* We need to write a complete 64-byte data block and encode the
324  * number actually sent in the first double-byte, LSB-order. That
325  * leaves at most 62 bytes of payload.
326  */
327 #define KLSI_HDR_LEN		2
328 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
329 						void *dest, size_t size)
330 {
331 	unsigned char *buf = dest;
332 	int count;
333 
334 	count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size,
335 								&port->lock);
336 	put_unaligned_le16(count, buf);
337 
338 	return count + KLSI_HDR_LEN;
339 }
340 
341 /* The data received is preceded by a length double-byte in LSB-first order.
342  */
343 static void klsi_105_process_read_urb(struct urb *urb)
344 {
345 	struct usb_serial_port *port = urb->context;
346 	unsigned char *data = urb->transfer_buffer;
347 	unsigned len;
348 
349 	/* empty urbs seem to happen, we ignore them */
350 	if (!urb->actual_length)
351 		return;
352 
353 	if (urb->actual_length <= KLSI_HDR_LEN) {
354 		dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
355 		return;
356 	}
357 
358 	len = get_unaligned_le16(data);
359 	if (len > urb->actual_length - KLSI_HDR_LEN) {
360 		dev_dbg(&port->dev, "%s - packet length mismatch\n", __func__);
361 		len = urb->actual_length - KLSI_HDR_LEN;
362 	}
363 
364 	tty_insert_flip_string(&port->port, data + KLSI_HDR_LEN, len);
365 	tty_flip_buffer_push(&port->port);
366 }
367 
368 static void klsi_105_set_termios(struct tty_struct *tty,
369 				 struct usb_serial_port *port,
370 				 const struct ktermios *old_termios)
371 {
372 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
373 	struct device *dev = &port->dev;
374 	unsigned int iflag = tty->termios.c_iflag;
375 	unsigned int old_iflag = old_termios->c_iflag;
376 	unsigned int cflag = tty->termios.c_cflag;
377 	unsigned int old_cflag = old_termios->c_cflag;
378 	struct klsi_105_port_settings *cfg;
379 	unsigned long flags;
380 	speed_t baud;
381 
382 	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
383 	if (!cfg)
384 		return;
385 
386 	/* lock while we are modifying the settings */
387 	spin_lock_irqsave(&priv->lock, flags);
388 
389 	/*
390 	 * Update baud rate
391 	 */
392 	baud = tty_get_baud_rate(tty);
393 
394 	switch (baud) {
395 	case 0: /* handled below */
396 		break;
397 	case 1200:
398 		priv->cfg.baudrate = kl5kusb105a_sio_b1200;
399 		break;
400 	case 2400:
401 		priv->cfg.baudrate = kl5kusb105a_sio_b2400;
402 		break;
403 	case 4800:
404 		priv->cfg.baudrate = kl5kusb105a_sio_b4800;
405 		break;
406 	case 9600:
407 		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
408 		break;
409 	case 19200:
410 		priv->cfg.baudrate = kl5kusb105a_sio_b19200;
411 		break;
412 	case 38400:
413 		priv->cfg.baudrate = kl5kusb105a_sio_b38400;
414 		break;
415 	case 57600:
416 		priv->cfg.baudrate = kl5kusb105a_sio_b57600;
417 		break;
418 	case 115200:
419 		priv->cfg.baudrate = kl5kusb105a_sio_b115200;
420 		break;
421 	default:
422 		dev_dbg(dev, "unsupported baudrate, using 9600\n");
423 		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
424 		baud = 9600;
425 		break;
426 	}
427 
428 	/*
429 	 * FIXME: implement B0 handling
430 	 *
431 	 * Maybe this should be simulated by sending read disable and read
432 	 * enable messages?
433 	 */
434 
435 	tty_encode_baud_rate(tty, baud, baud);
436 
437 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
438 		/* set the number of data bits */
439 		switch (cflag & CSIZE) {
440 		case CS5:
441 			dev_dbg(dev, "%s - 5 bits/byte not supported\n", __func__);
442 			spin_unlock_irqrestore(&priv->lock, flags);
443 			goto err;
444 		case CS6:
445 			dev_dbg(dev, "%s - 6 bits/byte not supported\n", __func__);
446 			spin_unlock_irqrestore(&priv->lock, flags);
447 			goto err;
448 		case CS7:
449 			priv->cfg.databits = kl5kusb105a_dtb_7;
450 			break;
451 		case CS8:
452 			priv->cfg.databits = kl5kusb105a_dtb_8;
453 			break;
454 		default:
455 			dev_err(dev, "CSIZE was not CS5-CS8, using default of 8\n");
456 			priv->cfg.databits = kl5kusb105a_dtb_8;
457 			break;
458 		}
459 	}
460 
461 	/*
462 	 * Update line control register (LCR)
463 	 */
464 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
465 	    || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
466 		/* Not currently supported */
467 		tty->termios.c_cflag &= ~(PARENB|PARODD|CSTOPB);
468 	}
469 	/*
470 	 * Set flow control: well, I do not really now how to handle DTR/RTS.
471 	 * Just do what we have seen with SniffUSB on Win98.
472 	 */
473 	if ((iflag & IXOFF) != (old_iflag & IXOFF)
474 	    || (iflag & IXON) != (old_iflag & IXON)
475 	    ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
476 		/* Not currently supported */
477 		tty->termios.c_cflag &= ~CRTSCTS;
478 	}
479 	memcpy(cfg, &priv->cfg, sizeof(*cfg));
480 	spin_unlock_irqrestore(&priv->lock, flags);
481 
482 	/* now commit changes to device */
483 	klsi_105_chg_port_settings(port, cfg);
484 err:
485 	kfree(cfg);
486 }
487 
488 static int klsi_105_tiocmget(struct tty_struct *tty)
489 {
490 	struct usb_serial_port *port = tty->driver_data;
491 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
492 	unsigned long flags;
493 	int rc;
494 	unsigned long line_state;
495 
496 	rc = klsi_105_get_line_state(port, &line_state);
497 	if (rc < 0) {
498 		dev_err(&port->dev,
499 			"Reading line control failed (error = %d)\n", rc);
500 		/* better return value? EAGAIN? */
501 		return rc;
502 	}
503 
504 	spin_lock_irqsave(&priv->lock, flags);
505 	priv->line_state = line_state;
506 	spin_unlock_irqrestore(&priv->lock, flags);
507 	dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
508 	return (int)line_state;
509 }
510 
511 module_usb_serial_driver(serial_drivers, id_table);
512 
513 MODULE_AUTHOR(DRIVER_AUTHOR);
514 MODULE_DESCRIPTION(DRIVER_DESC);
515 MODULE_LICENSE("GPL");
516