xref: /openbmc/linux/drivers/usb/serial/kl5kusb105.c (revision d198b34f)
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 	{ }		/* Terminating entry */
71 };
72 
73 MODULE_DEVICE_TABLE(usb, id_table);
74 
75 static 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 
96 static struct usb_serial_driver * const serial_drivers[] = {
97 	&kl5kusb105d_device, NULL
98 };
99 
100 struct 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 
108 struct 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 
122 static 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 */
149 static 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
166 static 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 
210 static 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 
234 static 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 
244 static 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 	/* READ_ON and urb submission */
280 	rc = usb_serial_generic_open(tty, port);
281 	if (rc) {
282 		retval = rc;
283 		goto err_free_cfg;
284 	}
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 
316 err_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);
325 err_generic_close:
326 	usb_serial_generic_close(port);
327 err_free_cfg:
328 	kfree(cfg);
329 
330 	return retval;
331 }
332 
333 static void klsi_105_close(struct usb_serial_port *port)
334 {
335 	int rc;
336 
337 	/* send READ_OFF */
338 	rc = usb_control_msg(port->serial->dev,
339 			     usb_sndctrlpipe(port->serial->dev, 0),
340 			     KL5KUSB105A_SIO_CONFIGURE,
341 			     USB_TYPE_VENDOR | USB_DIR_OUT,
342 			     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
343 			     0, /* index */
344 			     NULL, 0,
345 			     KLSI_TIMEOUT);
346 	if (rc < 0)
347 		dev_err(&port->dev, "failed to disable read: %d\n", rc);
348 
349 	/* shutdown our bulk reads and writes */
350 	usb_serial_generic_close(port);
351 }
352 
353 /* We need to write a complete 64-byte data block and encode the
354  * number actually sent in the first double-byte, LSB-order. That
355  * leaves at most 62 bytes of payload.
356  */
357 #define KLSI_HDR_LEN		2
358 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
359 						void *dest, size_t size)
360 {
361 	unsigned char *buf = dest;
362 	int count;
363 
364 	count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size,
365 								&port->lock);
366 	put_unaligned_le16(count, buf);
367 
368 	return count + KLSI_HDR_LEN;
369 }
370 
371 /* The data received is preceded by a length double-byte in LSB-first order.
372  */
373 static void klsi_105_process_read_urb(struct urb *urb)
374 {
375 	struct usb_serial_port *port = urb->context;
376 	unsigned char *data = urb->transfer_buffer;
377 	unsigned len;
378 
379 	/* empty urbs seem to happen, we ignore them */
380 	if (!urb->actual_length)
381 		return;
382 
383 	if (urb->actual_length <= KLSI_HDR_LEN) {
384 		dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
385 		return;
386 	}
387 
388 	len = get_unaligned_le16(data);
389 	if (len > urb->actual_length - KLSI_HDR_LEN) {
390 		dev_dbg(&port->dev, "%s - packet length mismatch\n", __func__);
391 		len = urb->actual_length - KLSI_HDR_LEN;
392 	}
393 
394 	tty_insert_flip_string(&port->port, data + KLSI_HDR_LEN, len);
395 	tty_flip_buffer_push(&port->port);
396 }
397 
398 static void klsi_105_set_termios(struct tty_struct *tty,
399 				 struct usb_serial_port *port,
400 				 struct ktermios *old_termios)
401 {
402 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
403 	struct device *dev = &port->dev;
404 	unsigned int iflag = tty->termios.c_iflag;
405 	unsigned int old_iflag = old_termios->c_iflag;
406 	unsigned int cflag = tty->termios.c_cflag;
407 	unsigned int old_cflag = old_termios->c_cflag;
408 	struct klsi_105_port_settings *cfg;
409 	unsigned long flags;
410 	speed_t baud;
411 
412 	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
413 	if (!cfg)
414 		return;
415 
416 	/* lock while we are modifying the settings */
417 	spin_lock_irqsave(&priv->lock, flags);
418 
419 	/*
420 	 * Update baud rate
421 	 */
422 	baud = tty_get_baud_rate(tty);
423 
424 	switch (baud) {
425 	case 0: /* handled below */
426 		break;
427 	case 1200:
428 		priv->cfg.baudrate = kl5kusb105a_sio_b1200;
429 		break;
430 	case 2400:
431 		priv->cfg.baudrate = kl5kusb105a_sio_b2400;
432 		break;
433 	case 4800:
434 		priv->cfg.baudrate = kl5kusb105a_sio_b4800;
435 		break;
436 	case 9600:
437 		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
438 		break;
439 	case 19200:
440 		priv->cfg.baudrate = kl5kusb105a_sio_b19200;
441 		break;
442 	case 38400:
443 		priv->cfg.baudrate = kl5kusb105a_sio_b38400;
444 		break;
445 	case 57600:
446 		priv->cfg.baudrate = kl5kusb105a_sio_b57600;
447 		break;
448 	case 115200:
449 		priv->cfg.baudrate = kl5kusb105a_sio_b115200;
450 		break;
451 	default:
452 		dev_dbg(dev, "unsupported baudrate, using 9600\n");
453 		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
454 		baud = 9600;
455 		break;
456 	}
457 
458 	/*
459 	 * FIXME: implement B0 handling
460 	 *
461 	 * Maybe this should be simulated by sending read disable and read
462 	 * enable messages?
463 	 */
464 
465 	tty_encode_baud_rate(tty, baud, baud);
466 
467 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
468 		/* set the number of data bits */
469 		switch (cflag & CSIZE) {
470 		case CS5:
471 			dev_dbg(dev, "%s - 5 bits/byte not supported\n", __func__);
472 			spin_unlock_irqrestore(&priv->lock, flags);
473 			goto err;
474 		case CS6:
475 			dev_dbg(dev, "%s - 6 bits/byte not supported\n", __func__);
476 			spin_unlock_irqrestore(&priv->lock, flags);
477 			goto err;
478 		case CS7:
479 			priv->cfg.databits = kl5kusb105a_dtb_7;
480 			break;
481 		case CS8:
482 			priv->cfg.databits = kl5kusb105a_dtb_8;
483 			break;
484 		default:
485 			dev_err(dev, "CSIZE was not CS5-CS8, using default of 8\n");
486 			priv->cfg.databits = kl5kusb105a_dtb_8;
487 			break;
488 		}
489 	}
490 
491 	/*
492 	 * Update line control register (LCR)
493 	 */
494 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
495 	    || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
496 		/* Not currently supported */
497 		tty->termios.c_cflag &= ~(PARENB|PARODD|CSTOPB);
498 	}
499 	/*
500 	 * Set flow control: well, I do not really now how to handle DTR/RTS.
501 	 * Just do what we have seen with SniffUSB on Win98.
502 	 */
503 	if ((iflag & IXOFF) != (old_iflag & IXOFF)
504 	    || (iflag & IXON) != (old_iflag & IXON)
505 	    ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
506 		/* Not currently supported */
507 		tty->termios.c_cflag &= ~CRTSCTS;
508 	}
509 	memcpy(cfg, &priv->cfg, sizeof(*cfg));
510 	spin_unlock_irqrestore(&priv->lock, flags);
511 
512 	/* now commit changes to device */
513 	klsi_105_chg_port_settings(port, cfg);
514 err:
515 	kfree(cfg);
516 }
517 
518 static int klsi_105_tiocmget(struct tty_struct *tty)
519 {
520 	struct usb_serial_port *port = tty->driver_data;
521 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
522 	unsigned long flags;
523 	int rc;
524 	unsigned long line_state;
525 
526 	rc = klsi_105_get_line_state(port, &line_state);
527 	if (rc < 0) {
528 		dev_err(&port->dev,
529 			"Reading line control failed (error = %d)\n", rc);
530 		/* better return value? EAGAIN? */
531 		return rc;
532 	}
533 
534 	spin_lock_irqsave(&priv->lock, flags);
535 	priv->line_state = line_state;
536 	spin_unlock_irqrestore(&priv->lock, flags);
537 	dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
538 	return (int)line_state;
539 }
540 
541 module_usb_serial_driver(serial_drivers, id_table);
542 
543 MODULE_AUTHOR(DRIVER_AUTHOR);
544 MODULE_DESCRIPTION(DRIVER_DESC);
545 MODULE_LICENSE("GPL");
546