xref: /openbmc/linux/drivers/usb/serial/kl5kusb105.c (revision 82e6fdd6)
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 int 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, struct ktermios *old);
60 static int  klsi_105_tiocmget(struct tty_struct *tty);
61 static void klsi_105_process_read_urb(struct urb *urb);
62 static 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  */
68 static const struct usb_device_id id_table[] = {
69 	{ USB_DEVICE(PALMCONNECT_VID, PALMCONNECT_PID) },
70 	{ USB_DEVICE(KLSI_VID, KLSI_KL5KUSB105D_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(port->serial->dev,
129 			usb_sndctrlpipe(port->serial->dev, 0),
130 			KL5KUSB105A_SIO_SET_DATA,
131 			USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_INTERFACE,
132 			0, /* value */
133 			0, /* index */
134 			settings,
135 			sizeof(struct klsi_105_port_settings),
136 			KLSI_TIMEOUT);
137 	if (rc < 0)
138 		dev_err(&port->dev,
139 			"Change port settings failed (error = %d)\n", rc);
140 
141 	dev_dbg(&port->dev,
142 		"pktlen %u, baudrate 0x%02x, databits %u, u1 %u, u2 %u\n",
143 		settings->pktlen, settings->baudrate, settings->databits,
144 		settings->unknown1, settings->unknown2);
145 
146 	return rc;
147 }
148 
149 /* translate a 16-bit status value from the device to linux's TIO bits */
150 static unsigned long klsi_105_status2linestate(const __u16 status)
151 {
152 	unsigned long res = 0;
153 
154 	res =   ((status & KL5KUSB105A_DSR) ? TIOCM_DSR : 0)
155 	      | ((status & KL5KUSB105A_CTS) ? TIOCM_CTS : 0)
156 	      ;
157 
158 	return res;
159 }
160 
161 /*
162  * Read line control via vendor command and return result through
163  * *line_state_p
164  */
165 /* It seems that the status buffer has always only 2 bytes length */
166 #define KLSI_STATUSBUF_LEN	2
167 static int klsi_105_get_line_state(struct usb_serial_port *port,
168 				   unsigned long *line_state_p)
169 {
170 	int rc;
171 	u8 *status_buf;
172 	__u16 status;
173 
174 	status_buf = kmalloc(KLSI_STATUSBUF_LEN, GFP_KERNEL);
175 	if (!status_buf)
176 		return -ENOMEM;
177 
178 	status_buf[0] = 0xff;
179 	status_buf[1] = 0xff;
180 	rc = usb_control_msg(port->serial->dev,
181 			     usb_rcvctrlpipe(port->serial->dev, 0),
182 			     KL5KUSB105A_SIO_POLL,
183 			     USB_TYPE_VENDOR | USB_DIR_IN,
184 			     0, /* value */
185 			     0, /* index */
186 			     status_buf, KLSI_STATUSBUF_LEN,
187 			     10000
188 			     );
189 	if (rc != KLSI_STATUSBUF_LEN) {
190 		dev_err(&port->dev, "reading line status failed: %d\n", rc);
191 		if (rc >= 0)
192 			rc = -EIO;
193 	} else {
194 		status = get_unaligned_le16(status_buf);
195 
196 		dev_dbg(&port->dev, "read status %02x %02x\n",
197 			status_buf[0], status_buf[1]);
198 
199 		*line_state_p = klsi_105_status2linestate(status);
200 	}
201 
202 	kfree(status_buf);
203 	return rc;
204 }
205 
206 
207 /*
208  * Driver's tty interface functions
209  */
210 
211 static int klsi_105_port_probe(struct usb_serial_port *port)
212 {
213 	struct klsi_105_private *priv;
214 
215 	priv = kmalloc(sizeof(*priv), GFP_KERNEL);
216 	if (!priv)
217 		return -ENOMEM;
218 
219 	/* set initial values for control structures */
220 	priv->cfg.pktlen    = 5;
221 	priv->cfg.baudrate  = kl5kusb105a_sio_b9600;
222 	priv->cfg.databits  = kl5kusb105a_dtb_8;
223 	priv->cfg.unknown1  = 0;
224 	priv->cfg.unknown2  = 1;
225 
226 	priv->line_state    = 0;
227 
228 	spin_lock_init(&priv->lock);
229 
230 	usb_set_serial_port_data(port, priv);
231 
232 	return 0;
233 }
234 
235 static int klsi_105_port_remove(struct usb_serial_port *port)
236 {
237 	struct klsi_105_private *priv;
238 
239 	priv = usb_get_serial_port_data(port);
240 	kfree(priv);
241 
242 	return 0;
243 }
244 
245 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
246 {
247 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
248 	int retval = 0;
249 	int rc;
250 	unsigned long line_state;
251 	struct klsi_105_port_settings *cfg;
252 	unsigned long flags;
253 
254 	/* Do a defined restart:
255 	 * Set up sane default baud rate and send the 'READ_ON'
256 	 * vendor command.
257 	 * FIXME: set modem line control (how?)
258 	 * Then read the modem line control and store values in
259 	 * priv->line_state.
260 	 */
261 	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
262 	if (!cfg)
263 		return -ENOMEM;
264 
265 	cfg->pktlen   = 5;
266 	cfg->baudrate = kl5kusb105a_sio_b9600;
267 	cfg->databits = kl5kusb105a_dtb_8;
268 	cfg->unknown1 = 0;
269 	cfg->unknown2 = 1;
270 	klsi_105_chg_port_settings(port, cfg);
271 
272 	spin_lock_irqsave(&priv->lock, flags);
273 	priv->cfg.pktlen   = cfg->pktlen;
274 	priv->cfg.baudrate = cfg->baudrate;
275 	priv->cfg.databits = cfg->databits;
276 	priv->cfg.unknown1 = cfg->unknown1;
277 	priv->cfg.unknown2 = cfg->unknown2;
278 	spin_unlock_irqrestore(&priv->lock, flags);
279 
280 	/* READ_ON and urb submission */
281 	rc = usb_serial_generic_open(tty, port);
282 	if (rc) {
283 		retval = rc;
284 		goto err_free_cfg;
285 	}
286 
287 	rc = usb_control_msg(port->serial->dev,
288 			     usb_sndctrlpipe(port->serial->dev, 0),
289 			     KL5KUSB105A_SIO_CONFIGURE,
290 			     USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_INTERFACE,
291 			     KL5KUSB105A_SIO_CONFIGURE_READ_ON,
292 			     0, /* index */
293 			     NULL,
294 			     0,
295 			     KLSI_TIMEOUT);
296 	if (rc < 0) {
297 		dev_err(&port->dev, "Enabling read failed (error = %d)\n", rc);
298 		retval = rc;
299 		goto err_generic_close;
300 	} else
301 		dev_dbg(&port->dev, "%s - enabled reading\n", __func__);
302 
303 	rc = klsi_105_get_line_state(port, &line_state);
304 	if (rc < 0) {
305 		retval = rc;
306 		goto err_disable_read;
307 	}
308 
309 	spin_lock_irqsave(&priv->lock, flags);
310 	priv->line_state = line_state;
311 	spin_unlock_irqrestore(&priv->lock, flags);
312 	dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__,
313 			line_state);
314 
315 	return 0;
316 
317 err_disable_read:
318 	usb_control_msg(port->serial->dev,
319 			     usb_sndctrlpipe(port->serial->dev, 0),
320 			     KL5KUSB105A_SIO_CONFIGURE,
321 			     USB_TYPE_VENDOR | USB_DIR_OUT,
322 			     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
323 			     0, /* index */
324 			     NULL, 0,
325 			     KLSI_TIMEOUT);
326 err_generic_close:
327 	usb_serial_generic_close(port);
328 err_free_cfg:
329 	kfree(cfg);
330 
331 	return retval;
332 }
333 
334 static void klsi_105_close(struct usb_serial_port *port)
335 {
336 	int rc;
337 
338 	/* send READ_OFF */
339 	rc = usb_control_msg(port->serial->dev,
340 			     usb_sndctrlpipe(port->serial->dev, 0),
341 			     KL5KUSB105A_SIO_CONFIGURE,
342 			     USB_TYPE_VENDOR | USB_DIR_OUT,
343 			     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
344 			     0, /* index */
345 			     NULL, 0,
346 			     KLSI_TIMEOUT);
347 	if (rc < 0)
348 		dev_err(&port->dev, "failed to disable read: %d\n", rc);
349 
350 	/* shutdown our bulk reads and writes */
351 	usb_serial_generic_close(port);
352 }
353 
354 /* We need to write a complete 64-byte data block and encode the
355  * number actually sent in the first double-byte, LSB-order. That
356  * leaves at most 62 bytes of payload.
357  */
358 #define KLSI_HDR_LEN		2
359 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
360 						void *dest, size_t size)
361 {
362 	unsigned char *buf = dest;
363 	int count;
364 
365 	count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size,
366 								&port->lock);
367 	put_unaligned_le16(count, buf);
368 
369 	return count + KLSI_HDR_LEN;
370 }
371 
372 /* The data received is preceded by a length double-byte in LSB-first order.
373  */
374 static void klsi_105_process_read_urb(struct urb *urb)
375 {
376 	struct usb_serial_port *port = urb->context;
377 	unsigned char *data = urb->transfer_buffer;
378 	unsigned len;
379 
380 	/* empty urbs seem to happen, we ignore them */
381 	if (!urb->actual_length)
382 		return;
383 
384 	if (urb->actual_length <= KLSI_HDR_LEN) {
385 		dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
386 		return;
387 	}
388 
389 	len = get_unaligned_le16(data);
390 	if (len > urb->actual_length - KLSI_HDR_LEN) {
391 		dev_dbg(&port->dev, "%s - packet length mismatch\n", __func__);
392 		len = urb->actual_length - KLSI_HDR_LEN;
393 	}
394 
395 	tty_insert_flip_string(&port->port, data + KLSI_HDR_LEN, len);
396 	tty_flip_buffer_push(&port->port);
397 }
398 
399 static void klsi_105_set_termios(struct tty_struct *tty,
400 				 struct usb_serial_port *port,
401 				 struct ktermios *old_termios)
402 {
403 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
404 	struct device *dev = &port->dev;
405 	unsigned int iflag = tty->termios.c_iflag;
406 	unsigned int old_iflag = old_termios->c_iflag;
407 	unsigned int cflag = tty->termios.c_cflag;
408 	unsigned int old_cflag = old_termios->c_cflag;
409 	struct klsi_105_port_settings *cfg;
410 	unsigned long flags;
411 	speed_t baud;
412 
413 	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
414 	if (!cfg)
415 		return;
416 
417 	/* lock while we are modifying the settings */
418 	spin_lock_irqsave(&priv->lock, flags);
419 
420 	/*
421 	 * Update baud rate
422 	 */
423 	baud = tty_get_baud_rate(tty);
424 
425 	switch (baud) {
426 	case 0: /* handled below */
427 		break;
428 	case 1200:
429 		priv->cfg.baudrate = kl5kusb105a_sio_b1200;
430 		break;
431 	case 2400:
432 		priv->cfg.baudrate = kl5kusb105a_sio_b2400;
433 		break;
434 	case 4800:
435 		priv->cfg.baudrate = kl5kusb105a_sio_b4800;
436 		break;
437 	case 9600:
438 		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
439 		break;
440 	case 19200:
441 		priv->cfg.baudrate = kl5kusb105a_sio_b19200;
442 		break;
443 	case 38400:
444 		priv->cfg.baudrate = kl5kusb105a_sio_b38400;
445 		break;
446 	case 57600:
447 		priv->cfg.baudrate = kl5kusb105a_sio_b57600;
448 		break;
449 	case 115200:
450 		priv->cfg.baudrate = kl5kusb105a_sio_b115200;
451 		break;
452 	default:
453 		dev_dbg(dev, "unsupported baudrate, using 9600\n");
454 		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
455 		baud = 9600;
456 		break;
457 	}
458 
459 	/*
460 	 * FIXME: implement B0 handling
461 	 *
462 	 * Maybe this should be simulated by sending read disable and read
463 	 * enable messages?
464 	 */
465 
466 	tty_encode_baud_rate(tty, baud, baud);
467 
468 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
469 		/* set the number of data bits */
470 		switch (cflag & CSIZE) {
471 		case CS5:
472 			dev_dbg(dev, "%s - 5 bits/byte not supported\n", __func__);
473 			spin_unlock_irqrestore(&priv->lock, flags);
474 			goto err;
475 		case CS6:
476 			dev_dbg(dev, "%s - 6 bits/byte not supported\n", __func__);
477 			spin_unlock_irqrestore(&priv->lock, flags);
478 			goto err;
479 		case CS7:
480 			priv->cfg.databits = kl5kusb105a_dtb_7;
481 			break;
482 		case CS8:
483 			priv->cfg.databits = kl5kusb105a_dtb_8;
484 			break;
485 		default:
486 			dev_err(dev, "CSIZE was not CS5-CS8, using default of 8\n");
487 			priv->cfg.databits = kl5kusb105a_dtb_8;
488 			break;
489 		}
490 	}
491 
492 	/*
493 	 * Update line control register (LCR)
494 	 */
495 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
496 	    || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
497 		/* Not currently supported */
498 		tty->termios.c_cflag &= ~(PARENB|PARODD|CSTOPB);
499 	}
500 	/*
501 	 * Set flow control: well, I do not really now how to handle DTR/RTS.
502 	 * Just do what we have seen with SniffUSB on Win98.
503 	 */
504 	if ((iflag & IXOFF) != (old_iflag & IXOFF)
505 	    || (iflag & IXON) != (old_iflag & IXON)
506 	    ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
507 		/* Not currently supported */
508 		tty->termios.c_cflag &= ~CRTSCTS;
509 	}
510 	memcpy(cfg, &priv->cfg, sizeof(*cfg));
511 	spin_unlock_irqrestore(&priv->lock, flags);
512 
513 	/* now commit changes to device */
514 	klsi_105_chg_port_settings(port, cfg);
515 err:
516 	kfree(cfg);
517 }
518 
519 static int klsi_105_tiocmget(struct tty_struct *tty)
520 {
521 	struct usb_serial_port *port = tty->driver_data;
522 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
523 	unsigned long flags;
524 	int rc;
525 	unsigned long line_state;
526 
527 	rc = klsi_105_get_line_state(port, &line_state);
528 	if (rc < 0) {
529 		dev_err(&port->dev,
530 			"Reading line control failed (error = %d)\n", rc);
531 		/* better return value? EAGAIN? */
532 		return rc;
533 	}
534 
535 	spin_lock_irqsave(&priv->lock, flags);
536 	priv->line_state = line_state;
537 	spin_unlock_irqrestore(&priv->lock, flags);
538 	dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
539 	return (int)line_state;
540 }
541 
542 module_usb_serial_driver(serial_drivers, id_table);
543 
544 MODULE_AUTHOR(DRIVER_AUTHOR);
545 MODULE_DESCRIPTION(DRIVER_DESC);
546 MODULE_LICENSE("GPL");
547