xref: /freebsd/sys/dev/usb/serial/uchcom.c (revision d2b2128a286a00ee53d79cb88b4e59bf42525cf9)
1 /*	$NetBSD: uchcom.c,v 1.1 2007/09/03 17:57:37 tshiozak Exp $	*/
2 
3 /*-
4  * Copyright (c) 2007, Takanori Watanabe
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * Copyright (c) 2007 The NetBSD Foundation, Inc.
31  * All rights reserved.
32  *
33  * This code is derived from software contributed to The NetBSD Foundation
34  * by Takuya SHIOZAKI (tshiozak@netbsd.org).
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. All advertising materials mentioning features or use of this software
45  *    must display the following acknowledgement:
46  *        This product includes software developed by the NetBSD
47  *        Foundation, Inc. and its contributors.
48  * 4. Neither the name of The NetBSD Foundation nor the names of its
49  *    contributors may be used to endorse or promote products derived
50  *    from this software without specific prior written permission.
51  *
52  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
53  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
54  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
55  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
56  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
57  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
58  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
59  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
60  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
61  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
62  * POSSIBILITY OF SUCH DAMAGE.
63  */
64 
65 #include <sys/cdefs.h>
66 __FBSDID("$FreeBSD$");
67 
68 /*
69  * driver for WinChipHead CH341/340, the worst USB-serial chip in the world.
70  */
71 
72 #include "usbdevs.h"
73 #include <dev/usb/usb.h>
74 #include <dev/usb/usb_mfunc.h>
75 #include <dev/usb/usb_error.h>
76 #include <dev/usb/usb_cdc.h>
77 #include <dev/usb/usb_ioctl.h>
78 
79 #define	USB_DEBUG_VAR uchcom_debug
80 
81 #include <dev/usb/usb_core.h>
82 #include <dev/usb/usb_debug.h>
83 #include <dev/usb/usb_process.h>
84 #include <dev/usb/usb_request.h>
85 #include <dev/usb/usb_lookup.h>
86 #include <dev/usb/usb_util.h>
87 #include <dev/usb/usb_busdma.h>
88 
89 #include <dev/usb/serial/usb_serial.h>
90 
91 #if USB_DEBUG
92 static int uchcom_debug = 0;
93 
94 SYSCTL_NODE(_hw_usb2, OID_AUTO, uchcom, CTLFLAG_RW, 0, "USB uchcom");
95 SYSCTL_INT(_hw_usb2_uchcom, OID_AUTO, debug, CTLFLAG_RW,
96     &uchcom_debug, 0, "uchcom debug level");
97 #endif
98 
99 #define	UCHCOM_IFACE_INDEX	0
100 #define	UCHCOM_CONFIG_INDEX	0
101 
102 #define	UCHCOM_REV_CH340	0x0250
103 #define	UCHCOM_INPUT_BUF_SIZE	8
104 
105 #define	UCHCOM_REQ_GET_VERSION	0x5F
106 #define	UCHCOM_REQ_READ_REG	0x95
107 #define	UCHCOM_REQ_WRITE_REG	0x9A
108 #define	UCHCOM_REQ_RESET	0xA1
109 #define	UCHCOM_REQ_SET_DTRRTS	0xA4
110 
111 #define	UCHCOM_REG_STAT1	0x06
112 #define	UCHCOM_REG_STAT2	0x07
113 #define	UCHCOM_REG_BPS_PRE	0x12
114 #define	UCHCOM_REG_BPS_DIV	0x13
115 #define	UCHCOM_REG_BPS_MOD	0x14
116 #define	UCHCOM_REG_BPS_PAD	0x0F
117 #define	UCHCOM_REG_BREAK1	0x05
118 #define	UCHCOM_REG_BREAK2	0x18
119 #define	UCHCOM_REG_LCR1		0x18
120 #define	UCHCOM_REG_LCR2		0x25
121 
122 #define	UCHCOM_VER_20		0x20
123 
124 #define	UCHCOM_BASE_UNKNOWN	0
125 #define	UCHCOM_BPS_MOD_BASE	20000000
126 #define	UCHCOM_BPS_MOD_BASE_OFS	1100
127 
128 #define	UCHCOM_DTR_MASK		0x20
129 #define	UCHCOM_RTS_MASK		0x40
130 
131 #define	UCHCOM_BRK1_MASK	0x01
132 #define	UCHCOM_BRK2_MASK	0x40
133 
134 #define	UCHCOM_LCR1_MASK	0xAF
135 #define	UCHCOM_LCR2_MASK	0x07
136 #define	UCHCOM_LCR1_PARENB	0x80
137 #define	UCHCOM_LCR2_PAREVEN	0x07
138 #define	UCHCOM_LCR2_PARODD	0x06
139 #define	UCHCOM_LCR2_PARMARK	0x05
140 #define	UCHCOM_LCR2_PARSPACE	0x04
141 
142 #define	UCHCOM_INTR_STAT1	0x02
143 #define	UCHCOM_INTR_STAT2	0x03
144 #define	UCHCOM_INTR_LEAST	4
145 
146 #define	UCHCOM_BULK_BUF_SIZE 1024	/* bytes */
147 
148 enum {
149 	UCHCOM_BULK_DT_WR,
150 	UCHCOM_BULK_DT_RD,
151 	UCHCOM_INTR_DT_RD,
152 	UCHCOM_N_TRANSFER,
153 };
154 
155 struct uchcom_softc {
156 	struct usb2_com_super_softc sc_super_ucom;
157 	struct usb2_com_softc sc_ucom;
158 
159 	struct usb2_xfer *sc_xfer[UCHCOM_N_TRANSFER];
160 	struct usb2_device *sc_udev;
161 	struct mtx sc_mtx;
162 
163 	uint8_t	sc_dtr;			/* local copy */
164 	uint8_t	sc_rts;			/* local copy */
165 	uint8_t	sc_version;
166 	uint8_t	sc_msr;
167 	uint8_t	sc_lsr;			/* local status register */
168 };
169 
170 struct uchcom_divider {
171 	uint8_t	dv_prescaler;
172 	uint8_t	dv_div;
173 	uint8_t	dv_mod;
174 };
175 
176 struct uchcom_divider_record {
177 	uint32_t dvr_high;
178 	uint32_t dvr_low;
179 	uint32_t dvr_base_clock;
180 	struct uchcom_divider dvr_divider;
181 };
182 
183 static const struct uchcom_divider_record dividers[] =
184 {
185 	{307200, 307200, UCHCOM_BASE_UNKNOWN, {7, 0xD9, 0}},
186 	{921600, 921600, UCHCOM_BASE_UNKNOWN, {7, 0xF3, 0}},
187 	{2999999, 23530, 6000000, {3, 0, 0}},
188 	{23529, 2942, 750000, {2, 0, 0}},
189 	{2941, 368, 93750, {1, 0, 0}},
190 	{367, 1, 11719, {0, 0, 0}},
191 };
192 
193 #define	NUM_DIVIDERS	(sizeof (dividers) / sizeof (dividers[0]))
194 
195 static const struct usb2_device_id uchcom_devs[] = {
196 	{USB_VPI(USB_VENDOR_WCH, USB_PRODUCT_WCH_CH341SER, 0)},
197 };
198 
199 /* protypes */
200 
201 static int	uchcom_pre_param(struct usb2_com_softc *, struct termios *);
202 static void	uchcom_cfg_get_status(struct usb2_com_softc *, uint8_t *,
203 		    uint8_t *);
204 static void	uchcom_cfg_param(struct usb2_com_softc *, struct termios *);
205 static void	uchcom_cfg_set_break(struct usb2_com_softc *, uint8_t);
206 static void	uchcom_cfg_set_dtr(struct usb2_com_softc *, uint8_t);
207 static void	uchcom_cfg_set_rts(struct usb2_com_softc *, uint8_t);
208 static void	uchcom_start_read(struct usb2_com_softc *);
209 static void	uchcom_start_write(struct usb2_com_softc *);
210 static void	uchcom_stop_read(struct usb2_com_softc *);
211 static void	uchcom_stop_write(struct usb2_com_softc *);
212 static void	uchcom_update_version(struct uchcom_softc *);
213 static void	uchcom_convert_status(struct uchcom_softc *, uint8_t);
214 static void	uchcom_update_status(struct uchcom_softc *);
215 static void	uchcom_set_dtrrts(struct uchcom_softc *);
216 static int	uchcom_calc_divider_settings(struct uchcom_divider *, uint32_t);
217 static void	uchcom_set_dte_rate(struct uchcom_softc *, uint32_t);
218 static void	uchcom_set_line_control(struct uchcom_softc *, tcflag_t);
219 static void	uchcom_clear_chip(struct uchcom_softc *);
220 static void	uchcom_reset_chip(struct uchcom_softc *);
221 
222 static device_probe_t uchcom_probe;
223 static device_attach_t uchcom_attach;
224 static device_detach_t uchcom_detach;
225 
226 static usb2_callback_t uchcom_intr_callback;
227 static usb2_callback_t uchcom_write_callback;
228 static usb2_callback_t uchcom_read_callback;
229 
230 static const struct usb2_config uchcom_config_data[UCHCOM_N_TRANSFER] = {
231 
232 	[UCHCOM_BULK_DT_WR] = {
233 		.type = UE_BULK,
234 		.endpoint = UE_ADDR_ANY,
235 		.direction = UE_DIR_OUT,
236 		.mh.bufsize = UCHCOM_BULK_BUF_SIZE,
237 		.mh.flags = {.pipe_bof = 1,.force_short_xfer = 1,},
238 		.mh.callback = &uchcom_write_callback,
239 	},
240 
241 	[UCHCOM_BULK_DT_RD] = {
242 		.type = UE_BULK,
243 		.endpoint = UE_ADDR_ANY,
244 		.direction = UE_DIR_IN,
245 		.mh.bufsize = UCHCOM_BULK_BUF_SIZE,
246 		.mh.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
247 		.mh.callback = &uchcom_read_callback,
248 	},
249 
250 	[UCHCOM_INTR_DT_RD] = {
251 		.type = UE_INTERRUPT,
252 		.endpoint = UE_ADDR_ANY,
253 		.direction = UE_DIR_IN,
254 		.mh.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
255 		.mh.bufsize = 0,	/* use wMaxPacketSize */
256 		.mh.callback = &uchcom_intr_callback,
257 	},
258 };
259 
260 struct usb2_com_callback uchcom_callback = {
261 	.usb2_com_cfg_get_status = &uchcom_cfg_get_status,
262 	.usb2_com_cfg_set_dtr = &uchcom_cfg_set_dtr,
263 	.usb2_com_cfg_set_rts = &uchcom_cfg_set_rts,
264 	.usb2_com_cfg_set_break = &uchcom_cfg_set_break,
265 	.usb2_com_cfg_param = &uchcom_cfg_param,
266 	.usb2_com_pre_param = &uchcom_pre_param,
267 	.usb2_com_start_read = &uchcom_start_read,
268 	.usb2_com_stop_read = &uchcom_stop_read,
269 	.usb2_com_start_write = &uchcom_start_write,
270 	.usb2_com_stop_write = &uchcom_stop_write,
271 };
272 
273 /* ----------------------------------------------------------------------
274  * driver entry points
275  */
276 
277 static int
278 uchcom_probe(device_t dev)
279 {
280 	struct usb2_attach_arg *uaa = device_get_ivars(dev);
281 
282 	DPRINTFN(11, "\n");
283 
284 	if (uaa->usb2_mode != USB_MODE_HOST) {
285 		return (ENXIO);
286 	}
287 	if (uaa->info.bConfigIndex != UCHCOM_CONFIG_INDEX) {
288 		return (ENXIO);
289 	}
290 	if (uaa->info.bIfaceIndex != UCHCOM_IFACE_INDEX) {
291 		return (ENXIO);
292 	}
293 	return (usb2_lookup_id_by_uaa(uchcom_devs, sizeof(uchcom_devs), uaa));
294 }
295 
296 static int
297 uchcom_attach(device_t dev)
298 {
299 	struct uchcom_softc *sc = device_get_softc(dev);
300 	struct usb2_attach_arg *uaa = device_get_ivars(dev);
301 	int error;
302 	uint8_t iface_index;
303 
304 	DPRINTFN(11, "\n");
305 
306 	device_set_usb2_desc(dev);
307 	mtx_init(&sc->sc_mtx, "uchcom", NULL, MTX_DEF);
308 
309 	sc->sc_udev = uaa->device;
310 
311 	switch (uaa->info.bcdDevice) {
312 	case UCHCOM_REV_CH340:
313 		device_printf(dev, "CH340 detected\n");
314 		break;
315 	default:
316 		device_printf(dev, "CH341 detected\n");
317 		break;
318 	}
319 
320 	iface_index = UCHCOM_IFACE_INDEX;
321 	error = usb2_transfer_setup(uaa->device,
322 	    &iface_index, sc->sc_xfer, uchcom_config_data,
323 	    UCHCOM_N_TRANSFER, sc, &sc->sc_mtx);
324 
325 	if (error) {
326 		DPRINTF("one or more missing USB endpoints, "
327 		    "error=%s\n", usb2_errstr(error));
328 		goto detach;
329 	}
330 	/*
331 	 * Do the initialization during attach so that the system does not
332 	 * sleep during open:
333 	 */
334 	uchcom_update_version(sc);
335 	uchcom_clear_chip(sc);
336 	uchcom_reset_chip(sc);
337 	uchcom_update_status(sc);
338 
339 	sc->sc_dtr = 1;
340 	sc->sc_rts = 1;
341 
342 	/* clear stall at first run */
343 	mtx_lock(&sc->sc_mtx);
344 	usb2_transfer_set_stall(sc->sc_xfer[UCHCOM_BULK_DT_WR]);
345 	usb2_transfer_set_stall(sc->sc_xfer[UCHCOM_BULK_DT_RD]);
346 	mtx_unlock(&sc->sc_mtx);
347 
348 	error = usb2_com_attach(&sc->sc_super_ucom, &sc->sc_ucom, 1, sc,
349 	    &uchcom_callback, &sc->sc_mtx);
350 	if (error) {
351 		goto detach;
352 	}
353 	return (0);
354 
355 detach:
356 	uchcom_detach(dev);
357 	return (ENXIO);
358 }
359 
360 static int
361 uchcom_detach(device_t dev)
362 {
363 	struct uchcom_softc *sc = device_get_softc(dev);
364 
365 	DPRINTFN(11, "\n");
366 
367 	usb2_com_detach(&sc->sc_super_ucom, &sc->sc_ucom, 1);
368 	usb2_transfer_unsetup(sc->sc_xfer, UCHCOM_N_TRANSFER);
369 	mtx_destroy(&sc->sc_mtx);
370 
371 	return (0);
372 }
373 
374 /* ----------------------------------------------------------------------
375  * low level i/o
376  */
377 
378 static void
379 uchcom_ctrl_write(struct uchcom_softc *sc, uint8_t reqno,
380     uint16_t value, uint16_t index)
381 {
382 	struct usb2_device_request req;
383 
384 	req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
385 	req.bRequest = reqno;
386 	USETW(req.wValue, value);
387 	USETW(req.wIndex, index);
388 	USETW(req.wLength, 0);
389 
390 	usb2_com_cfg_do_request(sc->sc_udev,
391 	    &sc->sc_ucom, &req, NULL, 0, 1000);
392 }
393 
394 static void
395 uchcom_ctrl_read(struct uchcom_softc *sc, uint8_t reqno,
396     uint16_t value, uint16_t index, void *buf, uint16_t buflen)
397 {
398 	struct usb2_device_request req;
399 
400 	req.bmRequestType = UT_READ_VENDOR_DEVICE;
401 	req.bRequest = reqno;
402 	USETW(req.wValue, value);
403 	USETW(req.wIndex, index);
404 	USETW(req.wLength, buflen);
405 
406 	usb2_com_cfg_do_request(sc->sc_udev,
407 	    &sc->sc_ucom, &req, buf, USB_SHORT_XFER_OK, 1000);
408 }
409 
410 static void
411 uchcom_write_reg(struct uchcom_softc *sc,
412     uint8_t reg1, uint8_t val1, uint8_t reg2, uint8_t val2)
413 {
414 	DPRINTF("0x%02X<-0x%02X, 0x%02X<-0x%02X\n",
415 	    (unsigned)reg1, (unsigned)val1,
416 	    (unsigned)reg2, (unsigned)val2);
417 	uchcom_ctrl_write(
418 	    sc, UCHCOM_REQ_WRITE_REG,
419 	    reg1 | ((uint16_t)reg2 << 8), val1 | ((uint16_t)val2 << 8));
420 }
421 
422 static void
423 uchcom_read_reg(struct uchcom_softc *sc,
424     uint8_t reg1, uint8_t *rval1, uint8_t reg2, uint8_t *rval2)
425 {
426 	uint8_t buf[UCHCOM_INPUT_BUF_SIZE];
427 
428 	uchcom_ctrl_read(
429 	    sc, UCHCOM_REQ_READ_REG,
430 	    reg1 | ((uint16_t)reg2 << 8), 0, buf, sizeof(buf));
431 
432 	DPRINTF("0x%02X->0x%02X, 0x%02X->0x%02X\n",
433 	    (unsigned)reg1, (unsigned)buf[0],
434 	    (unsigned)reg2, (unsigned)buf[1]);
435 
436 	if (rval1)
437 		*rval1 = buf[0];
438 	if (rval2)
439 		*rval2 = buf[1];
440 }
441 
442 static void
443 uchcom_get_version(struct uchcom_softc *sc, uint8_t *rver)
444 {
445 	uint8_t buf[UCHCOM_INPUT_BUF_SIZE];
446 
447 	uchcom_ctrl_read(
448 	    sc, UCHCOM_REQ_GET_VERSION, 0, 0, buf, sizeof(buf));
449 
450 	if (rver)
451 		*rver = buf[0];
452 }
453 
454 static void
455 uchcom_get_status(struct uchcom_softc *sc, uint8_t *rval)
456 {
457 	uchcom_read_reg(sc, UCHCOM_REG_STAT1, rval, UCHCOM_REG_STAT2, NULL);
458 }
459 
460 static void
461 uchcom_set_dtrrts_10(struct uchcom_softc *sc, uint8_t val)
462 {
463 	uchcom_write_reg(sc, UCHCOM_REG_STAT1, val, UCHCOM_REG_STAT1, val);
464 }
465 
466 static void
467 uchcom_set_dtrrts_20(struct uchcom_softc *sc, uint8_t val)
468 {
469 	uchcom_ctrl_write(sc, UCHCOM_REQ_SET_DTRRTS, val, 0);
470 }
471 
472 
473 /* ----------------------------------------------------------------------
474  * middle layer
475  */
476 
477 static void
478 uchcom_update_version(struct uchcom_softc *sc)
479 {
480 	uchcom_get_version(sc, &sc->sc_version);
481 }
482 
483 static void
484 uchcom_convert_status(struct uchcom_softc *sc, uint8_t cur)
485 {
486 	sc->sc_dtr = !(cur & UCHCOM_DTR_MASK);
487 	sc->sc_rts = !(cur & UCHCOM_RTS_MASK);
488 
489 	cur = ~cur & 0x0F;
490 	sc->sc_msr = (cur << 4) | ((sc->sc_msr >> 4) ^ cur);
491 }
492 
493 static void
494 uchcom_update_status(struct uchcom_softc *sc)
495 {
496 	uint8_t cur;
497 
498 	uchcom_get_status(sc, &cur);
499 	uchcom_convert_status(sc, cur);
500 }
501 
502 
503 static void
504 uchcom_set_dtrrts(struct uchcom_softc *sc)
505 {
506 	uint8_t val = 0;
507 
508 	if (sc->sc_dtr)
509 		val |= UCHCOM_DTR_MASK;
510 	if (sc->sc_rts)
511 		val |= UCHCOM_RTS_MASK;
512 
513 	if (sc->sc_version < UCHCOM_VER_20)
514 		uchcom_set_dtrrts_10(sc, ~val);
515 	else
516 		uchcom_set_dtrrts_20(sc, ~val);
517 }
518 
519 static void
520 uchcom_cfg_set_break(struct usb2_com_softc *ucom, uint8_t onoff)
521 {
522 	struct uchcom_softc *sc = ucom->sc_parent;
523 	uint8_t brk1;
524 	uint8_t brk2;
525 
526 	uchcom_read_reg(sc, UCHCOM_REG_BREAK1, &brk1, UCHCOM_REG_BREAK2, &brk2);
527 	if (onoff) {
528 		/* on - clear bits */
529 		brk1 &= ~UCHCOM_BRK1_MASK;
530 		brk2 &= ~UCHCOM_BRK2_MASK;
531 	} else {
532 		/* off - set bits */
533 		brk1 |= UCHCOM_BRK1_MASK;
534 		brk2 |= UCHCOM_BRK2_MASK;
535 	}
536 	uchcom_write_reg(sc, UCHCOM_REG_BREAK1, brk1, UCHCOM_REG_BREAK2, brk2);
537 }
538 
539 static int
540 uchcom_calc_divider_settings(struct uchcom_divider *dp, uint32_t rate)
541 {
542 	const struct uchcom_divider_record *rp;
543 	uint32_t div;
544 	uint32_t rem;
545 	uint32_t mod;
546 	uint8_t i;
547 
548 	/* find record */
549 	for (i = 0; i != NUM_DIVIDERS; i++) {
550 		if (dividers[i].dvr_high >= rate &&
551 		    dividers[i].dvr_low <= rate) {
552 			rp = &dividers[i];
553 			goto found;
554 		}
555 	}
556 	return (-1);
557 
558 found:
559 	dp->dv_prescaler = rp->dvr_divider.dv_prescaler;
560 	if (rp->dvr_base_clock == UCHCOM_BASE_UNKNOWN)
561 		dp->dv_div = rp->dvr_divider.dv_div;
562 	else {
563 		div = rp->dvr_base_clock / rate;
564 		rem = rp->dvr_base_clock % rate;
565 		if (div == 0 || div >= 0xFF)
566 			return (-1);
567 		if ((rem << 1) >= rate)
568 			div += 1;
569 		dp->dv_div = (uint8_t)-div;
570 	}
571 
572 	mod = UCHCOM_BPS_MOD_BASE / rate + UCHCOM_BPS_MOD_BASE_OFS;
573 	mod = mod + mod / 2;
574 
575 	dp->dv_mod = mod / 0x100;
576 
577 	return (0);
578 }
579 
580 static void
581 uchcom_set_dte_rate(struct uchcom_softc *sc, uint32_t rate)
582 {
583 	struct uchcom_divider dv;
584 
585 	if (uchcom_calc_divider_settings(&dv, rate))
586 		return;
587 
588 	uchcom_write_reg(sc,
589 	    UCHCOM_REG_BPS_PRE, dv.dv_prescaler,
590 	    UCHCOM_REG_BPS_DIV, dv.dv_div);
591 	uchcom_write_reg(sc,
592 	    UCHCOM_REG_BPS_MOD, dv.dv_mod,
593 	    UCHCOM_REG_BPS_PAD, 0);
594 }
595 
596 static void
597 uchcom_set_line_control(struct uchcom_softc *sc, tcflag_t cflag)
598 {
599 	uint8_t lcr1 = 0;
600 	uint8_t lcr2 = 0;
601 
602 	uchcom_read_reg(sc, UCHCOM_REG_LCR1, &lcr1, UCHCOM_REG_LCR2, &lcr2);
603 
604 	lcr1 &= ~UCHCOM_LCR1_MASK;
605 	lcr2 &= ~UCHCOM_LCR2_MASK;
606 
607 	/*
608 	 * XXX: it is difficult to handle the line control appropriately:
609 	 *   - CS8, !CSTOPB and any parity mode seems ok, but
610 	 *   - the chip doesn't have the function to calculate parity
611 	 *     in !CS8 mode.
612 	 *   - it is unclear that the chip supports CS5,6 mode.
613 	 *   - it is unclear how to handle stop bits.
614 	 */
615 
616 	if (cflag & PARENB) {
617 		lcr1 |= UCHCOM_LCR1_PARENB;
618 		if (cflag & PARODD)
619 			lcr2 |= UCHCOM_LCR2_PARODD;
620 		else
621 			lcr2 |= UCHCOM_LCR2_PAREVEN;
622 	}
623 	uchcom_write_reg(sc, UCHCOM_REG_LCR1, lcr1, UCHCOM_REG_LCR2, lcr2);
624 }
625 
626 static void
627 uchcom_clear_chip(struct uchcom_softc *sc)
628 {
629 	DPRINTF("\n");
630 	uchcom_ctrl_write(sc, UCHCOM_REQ_RESET, 0, 0);
631 }
632 
633 static void
634 uchcom_reset_chip(struct uchcom_softc *sc)
635 {
636 	uint16_t val;
637 	uint16_t idx;
638 	uint8_t lcr1;
639 	uint8_t lcr2;
640 	uint8_t pre;
641 	uint8_t div;
642 	uint8_t mod;
643 
644 	uchcom_read_reg(sc, UCHCOM_REG_LCR1, &lcr1, UCHCOM_REG_LCR2, &lcr2);
645 	uchcom_read_reg(sc, UCHCOM_REG_BPS_PRE, &pre, UCHCOM_REG_BPS_DIV, &div);
646 	uchcom_read_reg(sc, UCHCOM_REG_BPS_MOD, &mod, UCHCOM_REG_BPS_PAD, NULL);
647 
648 	val = 0;
649 	idx = 0;
650 	val |= (uint16_t)(lcr1 & 0xF0) << 8;
651 	val |= 0x01;
652 	val |= (uint16_t)(lcr2 & 0x0F) << 8;
653 	val |= 0x02;
654 	idx |= pre & 0x07;
655 	val |= 0x04;
656 	idx |= (uint16_t)div << 8;
657 	val |= 0x08;
658 	idx |= mod & 0xF8;
659 	val |= 0x10;
660 
661 	DPRINTF("reset v=0x%04X, i=0x%04X\n", val, idx);
662 
663 	uchcom_ctrl_write(sc, UCHCOM_REQ_RESET, val, idx);
664 }
665 
666 /* ----------------------------------------------------------------------
667  * methods for ucom
668  */
669 static void
670 uchcom_cfg_get_status(struct usb2_com_softc *ucom, uint8_t *lsr, uint8_t *msr)
671 {
672 	struct uchcom_softc *sc = ucom->sc_parent;
673 
674 	DPRINTF("\n");
675 
676 	*lsr = sc->sc_lsr;
677 	*msr = sc->sc_msr;
678 }
679 
680 static void
681 uchcom_cfg_set_dtr(struct usb2_com_softc *ucom, uint8_t onoff)
682 {
683 	struct uchcom_softc *sc = ucom->sc_parent;
684 
685 	DPRINTF("onoff = %d\n", onoff);
686 
687 	sc->sc_dtr = onoff;
688 	uchcom_set_dtrrts(sc);
689 }
690 
691 static void
692 uchcom_cfg_set_rts(struct usb2_com_softc *ucom, uint8_t onoff)
693 {
694 	struct uchcom_softc *sc = ucom->sc_parent;
695 
696 	DPRINTF("onoff = %d\n", onoff);
697 
698 	sc->sc_rts = onoff;
699 	uchcom_set_dtrrts(sc);
700 }
701 
702 static int
703 uchcom_pre_param(struct usb2_com_softc *ucom, struct termios *t)
704 {
705 	struct uchcom_divider dv;
706 
707 	switch (t->c_cflag & CSIZE) {
708 	case CS5:
709 	case CS6:
710 	case CS7:
711 		return (EIO);
712 	default:
713 		break;
714 	}
715 
716 	if (uchcom_calc_divider_settings(&dv, t->c_ospeed)) {
717 		return (EIO);
718 	}
719 	return (0);			/* success */
720 }
721 
722 static void
723 uchcom_cfg_param(struct usb2_com_softc *ucom, struct termios *t)
724 {
725 	struct uchcom_softc *sc = ucom->sc_parent;
726 
727 	uchcom_set_line_control(sc, t->c_cflag);
728 	uchcom_set_dte_rate(sc, t->c_ospeed);
729 }
730 
731 static void
732 uchcom_start_read(struct usb2_com_softc *ucom)
733 {
734 	struct uchcom_softc *sc = ucom->sc_parent;
735 
736 	/* start interrupt endpoint */
737 	usb2_transfer_start(sc->sc_xfer[UCHCOM_INTR_DT_RD]);
738 
739 	/* start read endpoint */
740 	usb2_transfer_start(sc->sc_xfer[UCHCOM_BULK_DT_RD]);
741 }
742 
743 static void
744 uchcom_stop_read(struct usb2_com_softc *ucom)
745 {
746 	struct uchcom_softc *sc = ucom->sc_parent;
747 
748 	/* stop interrupt endpoint */
749 	usb2_transfer_stop(sc->sc_xfer[UCHCOM_INTR_DT_RD]);
750 
751 	/* stop read endpoint */
752 	usb2_transfer_stop(sc->sc_xfer[UCHCOM_BULK_DT_RD]);
753 }
754 
755 static void
756 uchcom_start_write(struct usb2_com_softc *ucom)
757 {
758 	struct uchcom_softc *sc = ucom->sc_parent;
759 
760 	usb2_transfer_start(sc->sc_xfer[UCHCOM_BULK_DT_WR]);
761 }
762 
763 static void
764 uchcom_stop_write(struct usb2_com_softc *ucom)
765 {
766 	struct uchcom_softc *sc = ucom->sc_parent;
767 
768 	usb2_transfer_stop(sc->sc_xfer[UCHCOM_BULK_DT_WR]);
769 }
770 
771 /* ----------------------------------------------------------------------
772  * callback when the modem status is changed.
773  */
774 static void
775 uchcom_intr_callback(struct usb2_xfer *xfer)
776 {
777 	struct uchcom_softc *sc = xfer->priv_sc;
778 	uint8_t buf[UCHCOM_INTR_LEAST];
779 
780 	switch (USB_GET_STATE(xfer)) {
781 	case USB_ST_TRANSFERRED:
782 
783 		DPRINTF("actlen = %u\n", xfer->actlen);
784 
785 		if (xfer->actlen >= UCHCOM_INTR_LEAST) {
786 			usb2_copy_out(xfer->frbuffers, 0, buf,
787 			    UCHCOM_INTR_LEAST);
788 
789 			DPRINTF("data = 0x%02X 0x%02X 0x%02X 0x%02X\n",
790 			    (unsigned)buf[0], (unsigned)buf[1],
791 			    (unsigned)buf[2], (unsigned)buf[3]);
792 
793 			uchcom_convert_status(sc, buf[UCHCOM_INTR_STAT1]);
794 			usb2_com_status_change(&sc->sc_ucom);
795 		}
796 	case USB_ST_SETUP:
797 tr_setup:
798 		xfer->frlengths[0] = xfer->max_data_length;
799 		usb2_start_hardware(xfer);
800 		break;
801 
802 	default:			/* Error */
803 		if (xfer->error != USB_ERR_CANCELLED) {
804 			/* try to clear stall first */
805 			xfer->flags.stall_pipe = 1;
806 			goto tr_setup;
807 		}
808 		break;
809 	}
810 }
811 
812 static void
813 uchcom_write_callback(struct usb2_xfer *xfer)
814 {
815 	struct uchcom_softc *sc = xfer->priv_sc;
816 	uint32_t actlen;
817 
818 	switch (USB_GET_STATE(xfer)) {
819 	case USB_ST_SETUP:
820 	case USB_ST_TRANSFERRED:
821 tr_setup:
822 		if (usb2_com_get_data(&sc->sc_ucom, xfer->frbuffers, 0,
823 		    UCHCOM_BULK_BUF_SIZE, &actlen)) {
824 
825 			DPRINTF("actlen = %d\n", actlen);
826 
827 			xfer->frlengths[0] = actlen;
828 			usb2_start_hardware(xfer);
829 		}
830 		return;
831 
832 	default:			/* Error */
833 		if (xfer->error != USB_ERR_CANCELLED) {
834 			/* try to clear stall first */
835 			xfer->flags.stall_pipe = 1;
836 			goto tr_setup;
837 		}
838 		return;
839 
840 	}
841 }
842 
843 static void
844 uchcom_read_callback(struct usb2_xfer *xfer)
845 {
846 	struct uchcom_softc *sc = xfer->priv_sc;
847 
848 	switch (USB_GET_STATE(xfer)) {
849 	case USB_ST_TRANSFERRED:
850 		usb2_com_put_data(&sc->sc_ucom, xfer->frbuffers, 0, xfer->actlen);
851 
852 	case USB_ST_SETUP:
853 tr_setup:
854 		xfer->frlengths[0] = xfer->max_data_length;
855 		usb2_start_hardware(xfer);
856 		return;
857 
858 	default:			/* Error */
859 		if (xfer->error != USB_ERR_CANCELLED) {
860 			/* try to clear stall first */
861 			xfer->flags.stall_pipe = 1;
862 			goto tr_setup;
863 		}
864 		return;
865 	}
866 }
867 
868 static device_method_t uchcom_methods[] = {
869 	/* Device interface */
870 	DEVMETHOD(device_probe, uchcom_probe),
871 	DEVMETHOD(device_attach, uchcom_attach),
872 	DEVMETHOD(device_detach, uchcom_detach),
873 
874 	{0, 0}
875 };
876 
877 static driver_t uchcom_driver = {
878 	"ucom",
879 	uchcom_methods,
880 	sizeof(struct uchcom_softc)
881 };
882 
883 static devclass_t uchcom_devclass;
884 
885 DRIVER_MODULE(uchcom, uhub, uchcom_driver, uchcom_devclass, NULL, 0);
886 MODULE_DEPEND(uchcom, ucom, 1, 1, 1);
887 MODULE_DEPEND(uchcom, usb, 1, 1, 1);
888