xref: /openbmc/linux/drivers/usb/serial/kl5kusb105.c (revision 63705da3)
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, 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_send(port->serial->dev,
128 				  0,
129 				  KL5KUSB105A_SIO_SET_DATA,
130 				  USB_TYPE_VENDOR | USB_DIR_OUT |
131 				  USB_RECIP_INTERFACE,
132 				  0, /* value */
133 				  0, /* index */
134 				  settings,
135 				  sizeof(struct klsi_105_port_settings),
136 				  KLSI_TIMEOUT,
137 				  GFP_KERNEL);
138 	if (rc)
139 		dev_err(&port->dev,
140 			"Change port settings failed (error = %d)\n", rc);
141 
142 	dev_dbg(&port->dev,
143 		"pktlen %u, baudrate 0x%02x, databits %u, u1 %u, u2 %u\n",
144 		settings->pktlen, settings->baudrate, settings->databits,
145 		settings->unknown1, settings->unknown2);
146 
147 	return rc;
148 }
149 
150 /*
151  * Read line control via vendor command and return result through
152  * the state pointer.
153  */
154 static int klsi_105_get_line_state(struct usb_serial_port *port,
155 				   unsigned long *state)
156 {
157 	u16 status;
158 	int rc;
159 
160 	rc = usb_control_msg_recv(port->serial->dev, 0,
161 				  KL5KUSB105A_SIO_POLL,
162 				  USB_TYPE_VENDOR | USB_DIR_IN,
163 				  0, /* value */
164 				  0, /* index */
165 				  &status, sizeof(status),
166 				  10000,
167 				  GFP_KERNEL);
168 	if (rc) {
169 		dev_err(&port->dev, "reading line status failed: %d\n", rc);
170 		return rc;
171 	}
172 
173 	le16_to_cpus(&status);
174 
175 	dev_dbg(&port->dev, "read status %04x\n", status);
176 
177 	*state = ((status & KL5KUSB105A_DSR) ? TIOCM_DSR : 0) |
178 		 ((status & KL5KUSB105A_CTS) ? TIOCM_CTS : 0);
179 
180 	return 0;
181 }
182 
183 
184 /*
185  * Driver's tty interface functions
186  */
187 
188 static int klsi_105_port_probe(struct usb_serial_port *port)
189 {
190 	struct klsi_105_private *priv;
191 
192 	priv = kmalloc(sizeof(*priv), GFP_KERNEL);
193 	if (!priv)
194 		return -ENOMEM;
195 
196 	/* set initial values for control structures */
197 	priv->cfg.pktlen    = 5;
198 	priv->cfg.baudrate  = kl5kusb105a_sio_b9600;
199 	priv->cfg.databits  = kl5kusb105a_dtb_8;
200 	priv->cfg.unknown1  = 0;
201 	priv->cfg.unknown2  = 1;
202 
203 	priv->line_state    = 0;
204 
205 	spin_lock_init(&priv->lock);
206 
207 	usb_set_serial_port_data(port, priv);
208 
209 	return 0;
210 }
211 
212 static void klsi_105_port_remove(struct usb_serial_port *port)
213 {
214 	struct klsi_105_private *priv;
215 
216 	priv = usb_get_serial_port_data(port);
217 	kfree(priv);
218 }
219 
220 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
221 {
222 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
223 	int retval = 0;
224 	int rc;
225 	unsigned long line_state;
226 	struct klsi_105_port_settings cfg;
227 	unsigned long flags;
228 
229 	/* Do a defined restart:
230 	 * Set up sane default baud rate and send the 'READ_ON'
231 	 * vendor command.
232 	 * FIXME: set modem line control (how?)
233 	 * Then read the modem line control and store values in
234 	 * priv->line_state.
235 	 */
236 
237 	cfg.pktlen   = 5;
238 	cfg.baudrate = kl5kusb105a_sio_b9600;
239 	cfg.databits = kl5kusb105a_dtb_8;
240 	cfg.unknown1 = 0;
241 	cfg.unknown2 = 1;
242 	klsi_105_chg_port_settings(port, &cfg);
243 
244 	spin_lock_irqsave(&priv->lock, flags);
245 	priv->cfg.pktlen   = cfg.pktlen;
246 	priv->cfg.baudrate = cfg.baudrate;
247 	priv->cfg.databits = cfg.databits;
248 	priv->cfg.unknown1 = cfg.unknown1;
249 	priv->cfg.unknown2 = cfg.unknown2;
250 	spin_unlock_irqrestore(&priv->lock, flags);
251 
252 	/* READ_ON and urb submission */
253 	rc = usb_serial_generic_open(tty, port);
254 	if (rc)
255 		return rc;
256 
257 	rc = usb_control_msg(port->serial->dev,
258 			     usb_sndctrlpipe(port->serial->dev, 0),
259 			     KL5KUSB105A_SIO_CONFIGURE,
260 			     USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_INTERFACE,
261 			     KL5KUSB105A_SIO_CONFIGURE_READ_ON,
262 			     0, /* index */
263 			     NULL,
264 			     0,
265 			     KLSI_TIMEOUT);
266 	if (rc < 0) {
267 		dev_err(&port->dev, "Enabling read failed (error = %d)\n", rc);
268 		retval = rc;
269 		goto err_generic_close;
270 	} else
271 		dev_dbg(&port->dev, "%s - enabled reading\n", __func__);
272 
273 	rc = klsi_105_get_line_state(port, &line_state);
274 	if (rc < 0) {
275 		retval = rc;
276 		goto err_disable_read;
277 	}
278 
279 	spin_lock_irqsave(&priv->lock, flags);
280 	priv->line_state = line_state;
281 	spin_unlock_irqrestore(&priv->lock, flags);
282 	dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__,
283 			line_state);
284 
285 	return 0;
286 
287 err_disable_read:
288 	usb_control_msg(port->serial->dev,
289 			     usb_sndctrlpipe(port->serial->dev, 0),
290 			     KL5KUSB105A_SIO_CONFIGURE,
291 			     USB_TYPE_VENDOR | USB_DIR_OUT,
292 			     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
293 			     0, /* index */
294 			     NULL, 0,
295 			     KLSI_TIMEOUT);
296 err_generic_close:
297 	usb_serial_generic_close(port);
298 
299 	return retval;
300 }
301 
302 static void klsi_105_close(struct usb_serial_port *port)
303 {
304 	int rc;
305 
306 	/* send READ_OFF */
307 	rc = usb_control_msg(port->serial->dev,
308 			     usb_sndctrlpipe(port->serial->dev, 0),
309 			     KL5KUSB105A_SIO_CONFIGURE,
310 			     USB_TYPE_VENDOR | USB_DIR_OUT,
311 			     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
312 			     0, /* index */
313 			     NULL, 0,
314 			     KLSI_TIMEOUT);
315 	if (rc < 0)
316 		dev_err(&port->dev, "failed to disable read: %d\n", rc);
317 
318 	/* shutdown our bulk reads and writes */
319 	usb_serial_generic_close(port);
320 }
321 
322 /* We need to write a complete 64-byte data block and encode the
323  * number actually sent in the first double-byte, LSB-order. That
324  * leaves at most 62 bytes of payload.
325  */
326 #define KLSI_HDR_LEN		2
327 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
328 						void *dest, size_t size)
329 {
330 	unsigned char *buf = dest;
331 	int count;
332 
333 	count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size,
334 								&port->lock);
335 	put_unaligned_le16(count, buf);
336 
337 	return count + KLSI_HDR_LEN;
338 }
339 
340 /* The data received is preceded by a length double-byte in LSB-first order.
341  */
342 static void klsi_105_process_read_urb(struct urb *urb)
343 {
344 	struct usb_serial_port *port = urb->context;
345 	unsigned char *data = urb->transfer_buffer;
346 	unsigned len;
347 
348 	/* empty urbs seem to happen, we ignore them */
349 	if (!urb->actual_length)
350 		return;
351 
352 	if (urb->actual_length <= KLSI_HDR_LEN) {
353 		dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
354 		return;
355 	}
356 
357 	len = get_unaligned_le16(data);
358 	if (len > urb->actual_length - KLSI_HDR_LEN) {
359 		dev_dbg(&port->dev, "%s - packet length mismatch\n", __func__);
360 		len = urb->actual_length - KLSI_HDR_LEN;
361 	}
362 
363 	tty_insert_flip_string(&port->port, data + KLSI_HDR_LEN, len);
364 	tty_flip_buffer_push(&port->port);
365 }
366 
367 static void klsi_105_set_termios(struct tty_struct *tty,
368 				 struct usb_serial_port *port,
369 				 struct ktermios *old_termios)
370 {
371 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
372 	struct device *dev = &port->dev;
373 	unsigned int iflag = tty->termios.c_iflag;
374 	unsigned int old_iflag = old_termios->c_iflag;
375 	unsigned int cflag = tty->termios.c_cflag;
376 	unsigned int old_cflag = old_termios->c_cflag;
377 	struct klsi_105_port_settings *cfg;
378 	unsigned long flags;
379 	speed_t baud;
380 
381 	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
382 	if (!cfg)
383 		return;
384 
385 	/* lock while we are modifying the settings */
386 	spin_lock_irqsave(&priv->lock, flags);
387 
388 	/*
389 	 * Update baud rate
390 	 */
391 	baud = tty_get_baud_rate(tty);
392 
393 	switch (baud) {
394 	case 0: /* handled below */
395 		break;
396 	case 1200:
397 		priv->cfg.baudrate = kl5kusb105a_sio_b1200;
398 		break;
399 	case 2400:
400 		priv->cfg.baudrate = kl5kusb105a_sio_b2400;
401 		break;
402 	case 4800:
403 		priv->cfg.baudrate = kl5kusb105a_sio_b4800;
404 		break;
405 	case 9600:
406 		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
407 		break;
408 	case 19200:
409 		priv->cfg.baudrate = kl5kusb105a_sio_b19200;
410 		break;
411 	case 38400:
412 		priv->cfg.baudrate = kl5kusb105a_sio_b38400;
413 		break;
414 	case 57600:
415 		priv->cfg.baudrate = kl5kusb105a_sio_b57600;
416 		break;
417 	case 115200:
418 		priv->cfg.baudrate = kl5kusb105a_sio_b115200;
419 		break;
420 	default:
421 		dev_dbg(dev, "unsupported baudrate, using 9600\n");
422 		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
423 		baud = 9600;
424 		break;
425 	}
426 
427 	/*
428 	 * FIXME: implement B0 handling
429 	 *
430 	 * Maybe this should be simulated by sending read disable and read
431 	 * enable messages?
432 	 */
433 
434 	tty_encode_baud_rate(tty, baud, baud);
435 
436 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
437 		/* set the number of data bits */
438 		switch (cflag & CSIZE) {
439 		case CS5:
440 			dev_dbg(dev, "%s - 5 bits/byte not supported\n", __func__);
441 			spin_unlock_irqrestore(&priv->lock, flags);
442 			goto err;
443 		case CS6:
444 			dev_dbg(dev, "%s - 6 bits/byte not supported\n", __func__);
445 			spin_unlock_irqrestore(&priv->lock, flags);
446 			goto err;
447 		case CS7:
448 			priv->cfg.databits = kl5kusb105a_dtb_7;
449 			break;
450 		case CS8:
451 			priv->cfg.databits = kl5kusb105a_dtb_8;
452 			break;
453 		default:
454 			dev_err(dev, "CSIZE was not CS5-CS8, using default of 8\n");
455 			priv->cfg.databits = kl5kusb105a_dtb_8;
456 			break;
457 		}
458 	}
459 
460 	/*
461 	 * Update line control register (LCR)
462 	 */
463 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
464 	    || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
465 		/* Not currently supported */
466 		tty->termios.c_cflag &= ~(PARENB|PARODD|CSTOPB);
467 	}
468 	/*
469 	 * Set flow control: well, I do not really now how to handle DTR/RTS.
470 	 * Just do what we have seen with SniffUSB on Win98.
471 	 */
472 	if ((iflag & IXOFF) != (old_iflag & IXOFF)
473 	    || (iflag & IXON) != (old_iflag & IXON)
474 	    ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
475 		/* Not currently supported */
476 		tty->termios.c_cflag &= ~CRTSCTS;
477 	}
478 	memcpy(cfg, &priv->cfg, sizeof(*cfg));
479 	spin_unlock_irqrestore(&priv->lock, flags);
480 
481 	/* now commit changes to device */
482 	klsi_105_chg_port_settings(port, cfg);
483 err:
484 	kfree(cfg);
485 }
486 
487 static int klsi_105_tiocmget(struct tty_struct *tty)
488 {
489 	struct usb_serial_port *port = tty->driver_data;
490 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
491 	unsigned long flags;
492 	int rc;
493 	unsigned long line_state;
494 
495 	rc = klsi_105_get_line_state(port, &line_state);
496 	if (rc < 0) {
497 		dev_err(&port->dev,
498 			"Reading line control failed (error = %d)\n", rc);
499 		/* better return value? EAGAIN? */
500 		return rc;
501 	}
502 
503 	spin_lock_irqsave(&priv->lock, flags);
504 	priv->line_state = line_state;
505 	spin_unlock_irqrestore(&priv->lock, flags);
506 	dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
507 	return (int)line_state;
508 }
509 
510 module_usb_serial_driver(serial_drivers, id_table);
511 
512 MODULE_AUTHOR(DRIVER_AUTHOR);
513 MODULE_DESCRIPTION(DRIVER_DESC);
514 MODULE_LICENSE("GPL");
515