xref: /freebsd/sys/dev/usb/serial/umcs.c (revision 3c5ba95ad12285ad37c182a4bfc1b240ec6d18a7)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2010 Lev Serebryakov <lev@FreeBSD.org>.
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  * This driver supports several multiport USB-to-RS232 serial adapters driven
31  * by MosChip mos7820 and mos7840, bridge chips.
32  * The adapters are sold under many different brand names.
33  *
34  * Datasheets are available at MosChip www site at
35  * http://www.moschip.com.  The datasheets don't contain full
36  * programming information for the chip.
37  *
38  * It is nornal to have only two enabled ports in devices, based on
39  * quad-port mos7840.
40  *
41  */
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include <sys/stdint.h>
46 #include <sys/stddef.h>
47 #include <sys/param.h>
48 #include <sys/queue.h>
49 #include <sys/types.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/bus.h>
53 #include <sys/linker_set.h>
54 #include <sys/module.h>
55 #include <sys/lock.h>
56 #include <sys/mutex.h>
57 #include <sys/condvar.h>
58 #include <sys/sysctl.h>
59 #include <sys/sx.h>
60 #include <sys/unistd.h>
61 #include <sys/callout.h>
62 #include <sys/malloc.h>
63 #include <sys/priv.h>
64 
65 #include <dev/usb/usb.h>
66 #include <dev/usb/usbdi.h>
67 #include <dev/usb/usbdi_util.h>
68 #include <dev/usb/usb_cdc.h>
69 #include "usbdevs.h"
70 
71 #define	USB_DEBUG_VAR umcs_debug
72 #include <dev/usb/usb_debug.h>
73 #include <dev/usb/usb_process.h>
74 
75 #include <dev/usb/serial/usb_serial.h>
76 
77 #include <dev/usb/serial/umcs.h>
78 
79 #define	UMCS7840_MODVER	1
80 
81 #ifdef USB_DEBUG
82 static int umcs_debug = 0;
83 
84 static SYSCTL_NODE(_hw_usb, OID_AUTO, umcs, CTLFLAG_RW, 0, "USB umcs quadport serial adapter");
85 SYSCTL_INT(_hw_usb_umcs, OID_AUTO, debug, CTLFLAG_RWTUN, &umcs_debug, 0, "Debug level");
86 #endif					/* USB_DEBUG */
87 
88 
89 /*
90  * Two-port devices (both with 7820 chip and 7840 chip configured as two-port)
91  * have ports 0 and 2, with ports 1 and 3 omitted.
92  * So,PHYSICAL port numbers (indexes) on two-port device will be 0 and 2.
93  * This driver trys to use physical numbers as much as possible.
94  */
95 
96 /*
97  * Indexed by PHYSICAL port number.
98  * Pack non-regular registers to array to easier if-less access.
99  */
100 struct umcs7840_port_registers {
101 	uint8_t	reg_sp;			/* SP register. */
102 	uint8_t	reg_control;		/* CONTROL register. */
103 	uint8_t	reg_dcr;		/* DCR0 register. DCR1 & DCR2 can be
104 					 * calculated */
105 };
106 
107 static const struct umcs7840_port_registers umcs7840_port_registers[UMCS7840_MAX_PORTS] = {
108 	{.reg_sp = MCS7840_DEV_REG_SP1,.reg_control = MCS7840_DEV_REG_CONTROL1,.reg_dcr = MCS7840_DEV_REG_DCR0_1},
109 	{.reg_sp = MCS7840_DEV_REG_SP2,.reg_control = MCS7840_DEV_REG_CONTROL2,.reg_dcr = MCS7840_DEV_REG_DCR0_2},
110 	{.reg_sp = MCS7840_DEV_REG_SP3,.reg_control = MCS7840_DEV_REG_CONTROL3,.reg_dcr = MCS7840_DEV_REG_DCR0_3},
111 	{.reg_sp = MCS7840_DEV_REG_SP4,.reg_control = MCS7840_DEV_REG_CONTROL4,.reg_dcr = MCS7840_DEV_REG_DCR0_4},
112 };
113 
114 enum {
115 	UMCS7840_BULK_RD_EP,
116 	UMCS7840_BULK_WR_EP,
117 	UMCS7840_N_TRANSFERS
118 };
119 
120 struct umcs7840_softc_oneport {
121 	struct usb_xfer *sc_xfer[UMCS7840_N_TRANSFERS];	/* Control structures
122 							 * for two transfers */
123 
124 	uint8_t	sc_lcr;			/* local line control register */
125 	uint8_t	sc_mcr;			/* local modem control register */
126 };
127 
128 struct umcs7840_softc {
129 	struct ucom_super_softc sc_super_ucom;
130 	struct ucom_softc sc_ucom[UMCS7840_MAX_PORTS];	/* Need to be continuous
131 							 * array, so indexed by
132 							 * LOGICAL port
133 							 * (subunit) number */
134 
135 	struct usb_xfer *sc_intr_xfer;	/* Interrupt endpoint */
136 
137 	device_t sc_dev;		/* Device for error prints */
138 	struct usb_device *sc_udev;	/* USB Device for all operations */
139 	struct mtx sc_mtx;		/* ucom requires this */
140 
141 	uint8_t	sc_driver_done;		/* Flag when enumeration is finished */
142 
143 	uint8_t	sc_numports;		/* Number of ports (subunits) */
144 	struct umcs7840_softc_oneport sc_ports[UMCS7840_MAX_PORTS];	/* Indexed by PHYSICAL
145 									 * port number. */
146 };
147 
148 /* prototypes */
149 static usb_error_t umcs7840_get_reg_sync(struct umcs7840_softc *, uint8_t, uint8_t *);
150 static usb_error_t umcs7840_set_reg_sync(struct umcs7840_softc *, uint8_t, uint8_t);
151 static usb_error_t umcs7840_get_UART_reg_sync(struct umcs7840_softc *, uint8_t, uint8_t, uint8_t *);
152 static usb_error_t umcs7840_set_UART_reg_sync(struct umcs7840_softc *, uint8_t, uint8_t, uint8_t);
153 
154 static usb_error_t umcs7840_set_baudrate(struct umcs7840_softc *, uint8_t, uint32_t);
155 static usb_error_t umcs7840_calc_baudrate(uint32_t rate, uint16_t *, uint8_t *);
156 
157 static void	umcs7840_free(struct ucom_softc *);
158 static void umcs7840_cfg_get_status(struct ucom_softc *, uint8_t *, uint8_t *);
159 static void umcs7840_cfg_set_dtr(struct ucom_softc *, uint8_t);
160 static void umcs7840_cfg_set_rts(struct ucom_softc *, uint8_t);
161 static void umcs7840_cfg_set_break(struct ucom_softc *, uint8_t);
162 static void umcs7840_cfg_param(struct ucom_softc *, struct termios *);
163 static void umcs7840_cfg_open(struct ucom_softc *);
164 static void umcs7840_cfg_close(struct ucom_softc *);
165 
166 static int umcs7840_pre_param(struct ucom_softc *, struct termios *);
167 
168 static void umcs7840_start_read(struct ucom_softc *);
169 static void umcs7840_stop_read(struct ucom_softc *);
170 
171 static void umcs7840_start_write(struct ucom_softc *);
172 static void umcs7840_stop_write(struct ucom_softc *);
173 
174 static void umcs7840_poll(struct ucom_softc *ucom);
175 
176 static device_probe_t umcs7840_probe;
177 static device_attach_t umcs7840_attach;
178 static device_detach_t umcs7840_detach;
179 static void umcs7840_free_softc(struct umcs7840_softc *);
180 
181 static usb_callback_t umcs7840_intr_callback;
182 static usb_callback_t umcs7840_read_callback1;
183 static usb_callback_t umcs7840_read_callback2;
184 static usb_callback_t umcs7840_read_callback3;
185 static usb_callback_t umcs7840_read_callback4;
186 static usb_callback_t umcs7840_write_callback1;
187 static usb_callback_t umcs7840_write_callback2;
188 static usb_callback_t umcs7840_write_callback3;
189 static usb_callback_t umcs7840_write_callback4;
190 
191 static void umcs7840_read_callbackN(struct usb_xfer *, usb_error_t, uint8_t);
192 static void umcs7840_write_callbackN(struct usb_xfer *, usb_error_t, uint8_t);
193 
194 /* Indexed by LOGICAL port number (subunit), so two-port device uses 0 & 1 */
195 static usb_callback_t *umcs7840_rw_callbacks[UMCS7840_MAX_PORTS][UMCS7840_N_TRANSFERS] = {
196 	{&umcs7840_read_callback1, &umcs7840_write_callback1},
197 	{&umcs7840_read_callback2, &umcs7840_write_callback2},
198 	{&umcs7840_read_callback3, &umcs7840_write_callback3},
199 	{&umcs7840_read_callback4, &umcs7840_write_callback4},
200 };
201 
202 static const struct usb_config umcs7840_bulk_config_data[UMCS7840_N_TRANSFERS] = {
203 	[UMCS7840_BULK_RD_EP] = {
204 		.type = UE_BULK,
205 		.endpoint = 0x01,
206 		.direction = UE_DIR_IN,
207 		.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
208 		.bufsize = 0,		/* use wMaxPacketSize */
209 		.callback = &umcs7840_read_callback1,
210 		.if_index = 0,
211 	},
212 
213 	[UMCS7840_BULK_WR_EP] = {
214 		.type = UE_BULK,
215 		.endpoint = 0x02,
216 		.direction = UE_DIR_OUT,
217 		.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
218 		.bufsize = 0,		/* use wMaxPacketSize */
219 		.callback = &umcs7840_write_callback1,
220 		.if_index = 0,
221 	},
222 };
223 
224 static const struct usb_config umcs7840_intr_config_data[1] = {
225 	[0] = {
226 		.type = UE_INTERRUPT,
227 		.endpoint = 0x09,
228 		.direction = UE_DIR_IN,
229 		.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
230 		.bufsize = 0,		/* use wMaxPacketSize */
231 		.callback = &umcs7840_intr_callback,
232 		.if_index = 0,
233 	},
234 };
235 
236 static struct ucom_callback umcs7840_callback = {
237 	.ucom_cfg_get_status = &umcs7840_cfg_get_status,
238 
239 	.ucom_cfg_set_dtr = &umcs7840_cfg_set_dtr,
240 	.ucom_cfg_set_rts = &umcs7840_cfg_set_rts,
241 	.ucom_cfg_set_break = &umcs7840_cfg_set_break,
242 
243 	.ucom_cfg_param = &umcs7840_cfg_param,
244 	.ucom_cfg_open = &umcs7840_cfg_open,
245 	.ucom_cfg_close = &umcs7840_cfg_close,
246 
247 	.ucom_pre_param = &umcs7840_pre_param,
248 
249 	.ucom_start_read = &umcs7840_start_read,
250 	.ucom_stop_read = &umcs7840_stop_read,
251 
252 	.ucom_start_write = &umcs7840_start_write,
253 	.ucom_stop_write = &umcs7840_stop_write,
254 
255 	.ucom_poll = &umcs7840_poll,
256 	.ucom_free = &umcs7840_free,
257 };
258 
259 static const STRUCT_USB_HOST_ID umcs7840_devs[] = {
260 	{USB_VPI(USB_VENDOR_MOSCHIP, USB_PRODUCT_MOSCHIP_MCS7820, 0)},
261 	{USB_VPI(USB_VENDOR_MOSCHIP, USB_PRODUCT_MOSCHIP_MCS7840, 0)},
262 };
263 
264 static device_method_t umcs7840_methods[] = {
265 	DEVMETHOD(device_probe, umcs7840_probe),
266 	DEVMETHOD(device_attach, umcs7840_attach),
267 	DEVMETHOD(device_detach, umcs7840_detach),
268 	DEVMETHOD_END
269 };
270 
271 static devclass_t umcs7840_devclass;
272 
273 static driver_t umcs7840_driver = {
274 	.name = "umcs7840",
275 	.methods = umcs7840_methods,
276 	.size = sizeof(struct umcs7840_softc),
277 };
278 
279 DRIVER_MODULE(umcs7840, uhub, umcs7840_driver, umcs7840_devclass, 0, 0);
280 MODULE_DEPEND(umcs7840, ucom, 1, 1, 1);
281 MODULE_DEPEND(umcs7840, usb, 1, 1, 1);
282 MODULE_VERSION(umcs7840, UMCS7840_MODVER);
283 USB_PNP_HOST_INFO(umcs7840_devs);
284 
285 static int
286 umcs7840_probe(device_t dev)
287 {
288 	struct usb_attach_arg *uaa = device_get_ivars(dev);
289 
290 	if (uaa->usb_mode != USB_MODE_HOST)
291 		return (ENXIO);
292 	if (uaa->info.bConfigIndex != MCS7840_CONFIG_INDEX)
293 		return (ENXIO);
294 	if (uaa->info.bIfaceIndex != MCS7840_IFACE_INDEX)
295 		return (ENXIO);
296 	return (usbd_lookup_id_by_uaa(umcs7840_devs, sizeof(umcs7840_devs), uaa));
297 }
298 
299 static int
300 umcs7840_attach(device_t dev)
301 {
302 	struct usb_config umcs7840_config_tmp[UMCS7840_N_TRANSFERS];
303 	struct usb_attach_arg *uaa = device_get_ivars(dev);
304 	struct umcs7840_softc *sc = device_get_softc(dev);
305 
306 	uint8_t iface_index = MCS7840_IFACE_INDEX;
307 	int error;
308 	int subunit;
309 	int n;
310 	uint8_t data;
311 
312 	for (n = 0; n < UMCS7840_N_TRANSFERS; ++n)
313 		umcs7840_config_tmp[n] = umcs7840_bulk_config_data[n];
314 
315 	device_set_usb_desc(dev);
316 	mtx_init(&sc->sc_mtx, "umcs7840", NULL, MTX_DEF);
317 	ucom_ref(&sc->sc_super_ucom);
318 
319 	sc->sc_dev = dev;
320 	sc->sc_udev = uaa->device;
321 
322 	/*
323 	 * Get number of ports
324 	 * Documentation (full datasheet) says, that number of ports is
325 	 * set as MCS7840_DEV_MODE_SELECT24S bit in MODE R/Only
326 	 * register. But vendor driver uses these undocumented
327 	 * register & bit.
328 	 *
329 	 * Experiments show, that MODE register can have `0'
330 	 * (4 ports) bit on 2-port device, so use vendor driver's way.
331 	 *
332 	 * Also, see notes in header file for these constants.
333 	 */
334 	umcs7840_get_reg_sync(sc, MCS7840_DEV_REG_GPIO, &data);
335 	if (data & MCS7840_DEV_GPIO_4PORTS) {
336 		sc->sc_numports = 4;
337 		/* Store physical port numbers in sc_portno */
338 		sc->sc_ucom[0].sc_portno = 0;
339 		sc->sc_ucom[1].sc_portno = 1;
340 		sc->sc_ucom[2].sc_portno = 2;
341 		sc->sc_ucom[3].sc_portno = 3;
342 	} else {
343 		sc->sc_numports = 2;
344 		/* Store physical port numbers in sc_portno */
345 		sc->sc_ucom[0].sc_portno = 0;
346 		sc->sc_ucom[1].sc_portno = 2;	/* '1' is skipped */
347 	}
348 	device_printf(dev, "Chip mcs%04x, found %d active ports\n", uaa->info.idProduct, sc->sc_numports);
349 	if (!umcs7840_get_reg_sync(sc, MCS7840_DEV_REG_MODE, &data)) {
350 		device_printf(dev, "On-die confguration: RST: active %s, HRD: %s, PLL: %s, POR: %s, Ports: %s, EEPROM write %s, IrDA is %savailable\n",
351 		    (data & MCS7840_DEV_MODE_RESET) ? "low" : "high",
352 		    (data & MCS7840_DEV_MODE_SER_PRSNT) ? "yes" : "no",
353 		    (data & MCS7840_DEV_MODE_PLLBYPASS) ? "bypassed" : "avail",
354 		    (data & MCS7840_DEV_MODE_PORBYPASS) ? "bypassed" : "avail",
355 		    (data & MCS7840_DEV_MODE_SELECT24S) ? "2" : "4",
356 		    (data & MCS7840_DEV_MODE_EEPROMWR) ? "enabled" : "disabled",
357 		    (data & MCS7840_DEV_MODE_IRDA) ? "" : "not ");
358 	}
359 	/* Setup all transfers */
360 	for (subunit = 0; subunit < sc->sc_numports; ++subunit) {
361 		for (n = 0; n < UMCS7840_N_TRANSFERS; ++n) {
362 			/* Set endpoint address */
363 			umcs7840_config_tmp[n].endpoint = umcs7840_bulk_config_data[n].endpoint + 2 * sc->sc_ucom[subunit].sc_portno;
364 			umcs7840_config_tmp[n].callback = umcs7840_rw_callbacks[subunit][n];
365 		}
366 		error = usbd_transfer_setup(uaa->device,
367 		    &iface_index, sc->sc_ports[sc->sc_ucom[subunit].sc_portno].sc_xfer, umcs7840_config_tmp,
368 		    UMCS7840_N_TRANSFERS, sc, &sc->sc_mtx);
369 		if (error) {
370 			device_printf(dev, "allocating USB transfers failed for subunit %d of %d\n",
371 			    subunit + 1, sc->sc_numports);
372 			goto detach;
373 		}
374 	}
375 	error = usbd_transfer_setup(uaa->device,
376 	    &iface_index, &sc->sc_intr_xfer, umcs7840_intr_config_data,
377 	    1, sc, &sc->sc_mtx);
378 	if (error) {
379 		device_printf(dev, "allocating USB transfers failed for interrupt\n");
380 		goto detach;
381 	}
382 	/* clear stall at first run */
383 	mtx_lock(&sc->sc_mtx);
384 	for (subunit = 0; subunit < sc->sc_numports; ++subunit) {
385 		usbd_xfer_set_stall(sc->sc_ports[sc->sc_ucom[subunit].sc_portno].sc_xfer[UMCS7840_BULK_RD_EP]);
386 		usbd_xfer_set_stall(sc->sc_ports[sc->sc_ucom[subunit].sc_portno].sc_xfer[UMCS7840_BULK_WR_EP]);
387 	}
388 	mtx_unlock(&sc->sc_mtx);
389 
390 	error = ucom_attach(&sc->sc_super_ucom, sc->sc_ucom, sc->sc_numports, sc,
391 	    &umcs7840_callback, &sc->sc_mtx);
392 	if (error)
393 		goto detach;
394 
395 	ucom_set_pnpinfo_usb(&sc->sc_super_ucom, dev);
396 
397 	return (0);
398 
399 detach:
400 	umcs7840_detach(dev);
401 	return (ENXIO);
402 }
403 
404 static int
405 umcs7840_detach(device_t dev)
406 {
407 	struct umcs7840_softc *sc = device_get_softc(dev);
408 	int subunit;
409 
410 	ucom_detach(&sc->sc_super_ucom, sc->sc_ucom);
411 
412 	for (subunit = 0; subunit < sc->sc_numports; ++subunit)
413 		usbd_transfer_unsetup(sc->sc_ports[sc->sc_ucom[subunit].sc_portno].sc_xfer, UMCS7840_N_TRANSFERS);
414 	usbd_transfer_unsetup(&sc->sc_intr_xfer, 1);
415 
416 	device_claim_softc(dev);
417 
418 	umcs7840_free_softc(sc);
419 
420 	return (0);
421 }
422 
423 UCOM_UNLOAD_DRAIN(umcs7840);
424 
425 static void
426 umcs7840_free_softc(struct umcs7840_softc *sc)
427 {
428 	if (ucom_unref(&sc->sc_super_ucom)) {
429 		mtx_destroy(&sc->sc_mtx);
430 		device_free_softc(sc);
431 	}
432 }
433 
434 static void
435 umcs7840_free(struct ucom_softc *ucom)
436 {
437 	umcs7840_free_softc(ucom->sc_parent);
438 }
439 
440 static void
441 umcs7840_cfg_open(struct ucom_softc *ucom)
442 {
443 	struct umcs7840_softc *sc = ucom->sc_parent;
444 	uint16_t pn = ucom->sc_portno;
445 	uint8_t data;
446 
447 	/* If it very first open, finish global configuration */
448 	if (!sc->sc_driver_done) {
449 		/*
450 		 * USB enumeration is finished, pass internal memory to FIFOs
451 		 * If it is done in the end of "attach", kernel panics.
452 		 */
453 		if (umcs7840_get_reg_sync(sc, MCS7840_DEV_REG_CONTROL1, &data))
454 			return;
455 		data |= MCS7840_DEV_CONTROL1_DRIVER_DONE;
456 		if (umcs7840_set_reg_sync(sc, MCS7840_DEV_REG_CONTROL1, data))
457 			return;
458 		sc->sc_driver_done = 1;
459 	}
460 	/* Toggle reset bit on-off */
461 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, &data))
462 		return;
463 	data |= MCS7840_DEV_SPx_UART_RESET;
464 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, data))
465 		return;
466 	data &= ~MCS7840_DEV_SPx_UART_RESET;
467 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, data))
468 		return;
469 
470 	/* Set RS-232 mode */
471 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_SCRATCHPAD, MCS7840_UART_SCRATCHPAD_RS232))
472 		return;
473 
474 	/* Disable RX on time of initialization */
475 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_control, &data))
476 		return;
477 	data |= MCS7840_DEV_CONTROLx_RX_DISABLE;
478 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_control, data))
479 		return;
480 
481 	/* Disable all interrupts */
482 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_IER, 0))
483 		return;
484 
485 	/* Reset FIFO -- documented */
486 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_FCR, 0))
487 		return;
488 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_FCR,
489 	    MCS7840_UART_FCR_ENABLE | MCS7840_UART_FCR_FLUSHRHR |
490 	    MCS7840_UART_FCR_FLUSHTHR | MCS7840_UART_FCR_RTL_1_14))
491 		return;
492 
493 	/* Set 8 bit, no parity, 1 stop bit -- documented */
494 	sc->sc_ports[pn].sc_lcr = MCS7840_UART_LCR_DATALEN8 | MCS7840_UART_LCR_STOPB1;
495 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_LCR, sc->sc_ports[pn].sc_lcr))
496 		return;
497 
498 	/*
499 	 * Enable DTR/RTS on modem control, enable modem interrupts --
500 	 * documented
501 	 */
502 	sc->sc_ports[pn].sc_mcr = MCS7840_UART_MCR_DTR | MCS7840_UART_MCR_RTS | MCS7840_UART_MCR_IE;
503 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, sc->sc_ports[pn].sc_mcr))
504 		return;
505 
506 	/* Clearing Bulkin and Bulkout FIFO */
507 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, &data))
508 		return;
509 	data |= MCS7840_DEV_SPx_RESET_OUT_FIFO | MCS7840_DEV_SPx_RESET_IN_FIFO;
510 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, data))
511 		return;
512 	data &= ~(MCS7840_DEV_SPx_RESET_OUT_FIFO | MCS7840_DEV_SPx_RESET_IN_FIFO);
513 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, data))
514 		return;
515 
516 	/* Set speed 9600 */
517 	if (umcs7840_set_baudrate(sc, pn, 9600))
518 		return;
519 
520 
521 	/* Finally enable all interrupts -- documented */
522 	/*
523 	 * Copied from vendor driver, I don't know why we should read LCR
524 	 * here
525 	 */
526 	if (umcs7840_get_UART_reg_sync(sc, pn, MCS7840_UART_REG_LCR, &sc->sc_ports[pn].sc_lcr))
527 		return;
528 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_IER,
529 	    MCS7840_UART_IER_RXSTAT | MCS7840_UART_IER_MODEM))
530 		return;
531 
532 	/* Enable RX */
533 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_control, &data))
534 		return;
535 	data &= ~MCS7840_DEV_CONTROLx_RX_DISABLE;
536 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_control, data))
537 		return;
538 
539 	DPRINTF("Port %d has been opened\n", pn);
540 }
541 
542 static void
543 umcs7840_cfg_close(struct ucom_softc *ucom)
544 {
545 	struct umcs7840_softc *sc = ucom->sc_parent;
546 	uint16_t pn = ucom->sc_portno;
547 	uint8_t data;
548 
549 	umcs7840_stop_read(ucom);
550 	umcs7840_stop_write(ucom);
551 
552 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, 0);
553 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_IER, 0);
554 
555 	/* Disable RX */
556 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_control, &data))
557 		return;
558 	data |= MCS7840_DEV_CONTROLx_RX_DISABLE;
559 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_control, data))
560 		return;
561 	DPRINTF("Port %d has been closed\n", pn);
562 }
563 
564 static void
565 umcs7840_cfg_set_dtr(struct ucom_softc *ucom, uint8_t onoff)
566 {
567 	struct umcs7840_softc *sc = ucom->sc_parent;
568 	uint8_t pn = ucom->sc_portno;
569 
570 	if (onoff)
571 		sc->sc_ports[pn].sc_mcr |= MCS7840_UART_MCR_DTR;
572 	else
573 		sc->sc_ports[pn].sc_mcr &= ~MCS7840_UART_MCR_DTR;
574 
575 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, sc->sc_ports[pn].sc_mcr);
576 	DPRINTF("Port %d DTR set to: %s\n", pn, onoff ? "on" : "off");
577 }
578 
579 static void
580 umcs7840_cfg_set_rts(struct ucom_softc *ucom, uint8_t onoff)
581 {
582 	struct umcs7840_softc *sc = ucom->sc_parent;
583 	uint8_t pn = ucom->sc_portno;
584 
585 	if (onoff)
586 		sc->sc_ports[pn].sc_mcr |= MCS7840_UART_MCR_RTS;
587 	else
588 		sc->sc_ports[pn].sc_mcr &= ~MCS7840_UART_MCR_RTS;
589 
590 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, sc->sc_ports[pn].sc_mcr);
591 	DPRINTF("Port %d RTS set to: %s\n", pn, onoff ? "on" : "off");
592 }
593 
594 static void
595 umcs7840_cfg_set_break(struct ucom_softc *ucom, uint8_t onoff)
596 {
597 	struct umcs7840_softc *sc = ucom->sc_parent;
598 	uint8_t pn = ucom->sc_portno;
599 
600 	if (onoff)
601 		sc->sc_ports[pn].sc_lcr |= MCS7840_UART_LCR_BREAK;
602 	else
603 		sc->sc_ports[pn].sc_lcr &= ~MCS7840_UART_LCR_BREAK;
604 
605 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_LCR, sc->sc_ports[pn].sc_lcr);
606 	DPRINTF("Port %d BREAK set to: %s\n", pn, onoff ? "on" : "off");
607 }
608 
609 
610 static void
611 umcs7840_cfg_param(struct ucom_softc *ucom, struct termios *t)
612 {
613 	struct umcs7840_softc *sc = ucom->sc_parent;
614 	uint8_t pn = ucom->sc_portno;
615 	uint8_t lcr = sc->sc_ports[pn].sc_lcr;
616 	uint8_t mcr = sc->sc_ports[pn].sc_mcr;
617 
618 	DPRINTF("Port %d config:\n", pn);
619 	if (t->c_cflag & CSTOPB) {
620 		DPRINTF("  2 stop bits\n");
621 		lcr |= MCS7840_UART_LCR_STOPB2;
622 	} else {
623 		lcr |= MCS7840_UART_LCR_STOPB1;
624 		DPRINTF("  1 stop bit\n");
625 	}
626 
627 	lcr &= ~MCS7840_UART_LCR_PARITYMASK;
628 	if (t->c_cflag & PARENB) {
629 		lcr |= MCS7840_UART_LCR_PARITYON;
630 		if (t->c_cflag & PARODD) {
631 			lcr = MCS7840_UART_LCR_PARITYODD;
632 			DPRINTF("  parity on - odd\n");
633 		} else {
634 			lcr = MCS7840_UART_LCR_PARITYEVEN;
635 			DPRINTF("  parity on - even\n");
636 		}
637 	} else {
638 		lcr &= ~MCS7840_UART_LCR_PARITYON;
639 		DPRINTF("  parity off\n");
640 	}
641 
642 	lcr &= ~MCS7840_UART_LCR_DATALENMASK;
643 	switch (t->c_cflag & CSIZE) {
644 	case CS5:
645 		lcr |= MCS7840_UART_LCR_DATALEN5;
646 		DPRINTF("  5 bit\n");
647 		break;
648 	case CS6:
649 		lcr |= MCS7840_UART_LCR_DATALEN6;
650 		DPRINTF("  6 bit\n");
651 		break;
652 	case CS7:
653 		lcr |= MCS7840_UART_LCR_DATALEN7;
654 		DPRINTF("  7 bit\n");
655 		break;
656 	case CS8:
657 		lcr |= MCS7840_UART_LCR_DATALEN8;
658 		DPRINTF("  8 bit\n");
659 		break;
660 	}
661 
662 	if (t->c_cflag & CRTSCTS) {
663 		mcr |= MCS7840_UART_MCR_CTSRTS;
664 		DPRINTF("  CTS/RTS\n");
665 	} else
666 		mcr &= ~MCS7840_UART_MCR_CTSRTS;
667 
668 	if (t->c_cflag & (CDTR_IFLOW | CDSR_OFLOW)) {
669 		mcr |= MCS7840_UART_MCR_DTRDSR;
670 		DPRINTF("  DTR/DSR\n");
671 	} else
672 		mcr &= ~MCS7840_UART_MCR_DTRDSR;
673 
674 	sc->sc_ports[pn].sc_lcr = lcr;
675 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_LCR, sc->sc_ports[pn].sc_lcr);
676 	DPRINTF("Port %d LCR=%02x\n", pn, sc->sc_ports[pn].sc_lcr);
677 
678 	sc->sc_ports[pn].sc_mcr = mcr;
679 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, sc->sc_ports[pn].sc_mcr);
680 	DPRINTF("Port %d MCR=%02x\n", pn, sc->sc_ports[pn].sc_mcr);
681 
682 	umcs7840_set_baudrate(sc, pn, t->c_ospeed);
683 }
684 
685 
686 static int
687 umcs7840_pre_param(struct ucom_softc *ucom, struct termios *t)
688 {
689 	uint8_t clk;
690 	uint16_t divisor;
691 
692 	if (umcs7840_calc_baudrate(t->c_ospeed, &divisor, &clk) || !divisor)
693 		return (EINVAL);
694 	return (0);
695 }
696 
697 static void
698 umcs7840_start_read(struct ucom_softc *ucom)
699 {
700 	struct umcs7840_softc *sc = ucom->sc_parent;
701 	uint8_t pn = ucom->sc_portno;
702 
703 	/* Start interrupt transfer */
704 	usbd_transfer_start(sc->sc_intr_xfer);
705 
706 	/* Start read transfer */
707 	usbd_transfer_start(sc->sc_ports[pn].sc_xfer[UMCS7840_BULK_RD_EP]);
708 }
709 
710 static void
711 umcs7840_stop_read(struct ucom_softc *ucom)
712 {
713 	struct umcs7840_softc *sc = ucom->sc_parent;
714 	uint8_t pn = ucom->sc_portno;
715 
716 	/* Stop read transfer */
717 	usbd_transfer_stop(sc->sc_ports[pn].sc_xfer[UMCS7840_BULK_RD_EP]);
718 }
719 
720 static void
721 umcs7840_start_write(struct ucom_softc *ucom)
722 {
723 	struct umcs7840_softc *sc = ucom->sc_parent;
724 	uint8_t pn = ucom->sc_portno;
725 
726 	/* Start interrupt transfer */
727 	usbd_transfer_start(sc->sc_intr_xfer);
728 
729 	/* Start write transfer */
730 	usbd_transfer_start(sc->sc_ports[pn].sc_xfer[UMCS7840_BULK_WR_EP]);
731 }
732 
733 static void
734 umcs7840_stop_write(struct ucom_softc *ucom)
735 {
736 	struct umcs7840_softc *sc = ucom->sc_parent;
737 	uint8_t pn = ucom->sc_portno;
738 
739 	/* Stop write transfer */
740 	usbd_transfer_stop(sc->sc_ports[pn].sc_xfer[UMCS7840_BULK_WR_EP]);
741 }
742 
743 static void
744 umcs7840_cfg_get_status(struct ucom_softc *ucom, uint8_t *lsr, uint8_t *msr)
745 {
746 	struct umcs7840_softc *sc = ucom->sc_parent;
747 	uint8_t pn = ucom->sc_portno;
748 	uint8_t	hw_msr = 0;	/* local modem status register */
749 
750 	/*
751 	 * Read status registers.  MSR bits need translation from ns16550 to
752 	 * SER_* values.  LSR bits are ns16550 in hardware and ucom.
753 	 */
754 	umcs7840_get_UART_reg_sync(sc, pn, MCS7840_UART_REG_LSR, lsr);
755 	umcs7840_get_UART_reg_sync(sc, pn, MCS7840_UART_REG_MSR, &hw_msr);
756 
757 	if (hw_msr & MCS7840_UART_MSR_NEGCTS)
758 		*msr |= SER_CTS;
759 
760 	if (hw_msr & MCS7840_UART_MSR_NEGDCD)
761 		*msr |= SER_DCD;
762 
763 	if (hw_msr & MCS7840_UART_MSR_NEGRI)
764 		*msr |= SER_RI;
765 
766 	if (hw_msr & MCS7840_UART_MSR_NEGDSR)
767 		*msr |= SER_DSR;
768 
769 	DPRINTF("Port %d status: LSR=%02x MSR=%02x\n", ucom->sc_portno, *lsr, *msr);
770 }
771 
772 static void
773 umcs7840_intr_callback(struct usb_xfer *xfer, usb_error_t error)
774 {
775 	struct umcs7840_softc *sc = usbd_xfer_softc(xfer);
776 	struct usb_page_cache *pc;
777 	uint8_t buf[13];
778 	int actlen;
779 	int subunit;
780 
781 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
782 
783 	switch (USB_GET_STATE(xfer)) {
784 	case USB_ST_TRANSFERRED:
785 		if (actlen == 5 || actlen == 13) {
786 			pc = usbd_xfer_get_frame(xfer, 0);
787 			usbd_copy_out(pc, 0, buf, actlen);
788 			/* Check status of all ports */
789 			for (subunit = 0; subunit < sc->sc_numports; ++subunit) {
790 				uint8_t pn = sc->sc_ucom[subunit].sc_portno;
791 
792 				if (buf[pn] & MCS7840_UART_ISR_NOPENDING)
793 					continue;
794 				DPRINTF("Port %d has pending interrupt: %02x (FIFO: %02x)\n", pn, buf[pn] & MCS7840_UART_ISR_INTMASK, buf[pn] & (~MCS7840_UART_ISR_INTMASK));
795 				switch (buf[pn] & MCS7840_UART_ISR_INTMASK) {
796 				case MCS7840_UART_ISR_RXERR:
797 				case MCS7840_UART_ISR_RXHASDATA:
798 				case MCS7840_UART_ISR_RXTIMEOUT:
799 				case MCS7840_UART_ISR_MSCHANGE:
800 					ucom_status_change(&sc->sc_ucom[subunit]);
801 					break;
802 				default:
803 					/* Do nothing */
804 					break;
805 				}
806 			}
807 		} else
808 			device_printf(sc->sc_dev, "Invalid interrupt data length %d", actlen);
809 		/* FALLTHROUGH */
810 	case USB_ST_SETUP:
811 tr_setup:
812 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
813 		usbd_transfer_submit(xfer);
814 		return;
815 
816 	default:			/* Error */
817 		if (error != USB_ERR_CANCELLED) {
818 			/* try to clear stall first */
819 			usbd_xfer_set_stall(xfer);
820 			goto tr_setup;
821 		}
822 		return;
823 	}
824 }
825 
826 static void
827 umcs7840_read_callback1(struct usb_xfer *xfer, usb_error_t error)
828 {
829 	umcs7840_read_callbackN(xfer, error, 0);
830 }
831 
832 static void
833 umcs7840_read_callback2(struct usb_xfer *xfer, usb_error_t error)
834 {
835 	umcs7840_read_callbackN(xfer, error, 1);
836 }
837 static void
838 umcs7840_read_callback3(struct usb_xfer *xfer, usb_error_t error)
839 {
840 	umcs7840_read_callbackN(xfer, error, 2);
841 }
842 
843 static void
844 umcs7840_read_callback4(struct usb_xfer *xfer, usb_error_t error)
845 {
846 	umcs7840_read_callbackN(xfer, error, 3);
847 }
848 
849 static void
850 umcs7840_read_callbackN(struct usb_xfer *xfer, usb_error_t error, uint8_t subunit)
851 {
852 	struct umcs7840_softc *sc = usbd_xfer_softc(xfer);
853 	struct ucom_softc *ucom = &sc->sc_ucom[subunit];
854 	struct usb_page_cache *pc;
855 	int actlen;
856 
857 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
858 
859 	DPRINTF("Port %d read, state = %d, data length = %d\n", ucom->sc_portno, USB_GET_STATE(xfer), actlen);
860 
861 	switch (USB_GET_STATE(xfer)) {
862 	case USB_ST_TRANSFERRED:
863 		pc = usbd_xfer_get_frame(xfer, 0);
864 		ucom_put_data(ucom, pc, 0, actlen);
865 		/* FALLTHROUGH */
866 	case USB_ST_SETUP:
867 tr_setup:
868 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
869 		usbd_transfer_submit(xfer);
870 		return;
871 
872 	default:			/* Error */
873 		if (error != USB_ERR_CANCELLED) {
874 			/* try to clear stall first */
875 			usbd_xfer_set_stall(xfer);
876 			goto tr_setup;
877 		}
878 		return;
879 	}
880 }
881 
882 static void
883 umcs7840_write_callback1(struct usb_xfer *xfer, usb_error_t error)
884 {
885 	umcs7840_write_callbackN(xfer, error, 0);
886 }
887 
888 static void
889 umcs7840_write_callback2(struct usb_xfer *xfer, usb_error_t error)
890 {
891 	umcs7840_write_callbackN(xfer, error, 1);
892 }
893 
894 static void
895 umcs7840_write_callback3(struct usb_xfer *xfer, usb_error_t error)
896 {
897 	umcs7840_write_callbackN(xfer, error, 2);
898 }
899 
900 static void
901 umcs7840_write_callback4(struct usb_xfer *xfer, usb_error_t error)
902 {
903 	umcs7840_write_callbackN(xfer, error, 3);
904 }
905 
906 static void
907 umcs7840_write_callbackN(struct usb_xfer *xfer, usb_error_t error, uint8_t subunit)
908 {
909 	struct umcs7840_softc *sc = usbd_xfer_softc(xfer);
910 	struct ucom_softc *ucom = &sc->sc_ucom[subunit];
911 	struct usb_page_cache *pc;
912 	uint32_t actlen;
913 
914 	DPRINTF("Port %d write, state = %d\n", ucom->sc_portno, USB_GET_STATE(xfer));
915 
916 	switch (USB_GET_STATE(xfer)) {
917 	case USB_ST_SETUP:
918 	case USB_ST_TRANSFERRED:
919 tr_setup:
920 		pc = usbd_xfer_get_frame(xfer, 0);
921 		if (ucom_get_data(ucom, pc, 0, usbd_xfer_max_len(xfer), &actlen)) {
922 			DPRINTF("Port %d write, has %d bytes\n", ucom->sc_portno, actlen);
923 			usbd_xfer_set_frame_len(xfer, 0, actlen);
924 			usbd_transfer_submit(xfer);
925 		}
926 		return;
927 
928 	default:			/* Error */
929 		if (error != USB_ERR_CANCELLED) {
930 			/* try to clear stall first */
931 			usbd_xfer_set_stall(xfer);
932 			goto tr_setup;
933 		}
934 		return;
935 	}
936 }
937 
938 static void
939 umcs7840_poll(struct ucom_softc *ucom)
940 {
941 	struct umcs7840_softc *sc = ucom->sc_parent;
942 
943 	DPRINTF("Port %d poll\n", ucom->sc_portno);
944 	usbd_transfer_poll(sc->sc_ports[ucom->sc_portno].sc_xfer, UMCS7840_N_TRANSFERS);
945 	usbd_transfer_poll(&sc->sc_intr_xfer, 1);
946 }
947 
948 static usb_error_t
949 umcs7840_get_reg_sync(struct umcs7840_softc *sc, uint8_t reg, uint8_t *data)
950 {
951 	struct usb_device_request req;
952 	usb_error_t err;
953 	uint16_t len;
954 
955 	req.bmRequestType = UT_READ_VENDOR_DEVICE;
956 	req.bRequest = MCS7840_RDREQ;
957 	USETW(req.wValue, 0);
958 	USETW(req.wIndex, reg);
959 	USETW(req.wLength, UMCS7840_READ_LENGTH);
960 
961 	err = usbd_do_request_proc(sc->sc_udev, &sc->sc_super_ucom.sc_tq, &req, (void *)data, 0, &len, UMCS7840_CTRL_TIMEOUT);
962 	if (err == USB_ERR_NORMAL_COMPLETION && len != 1) {
963 		device_printf(sc->sc_dev, "Reading register %d failed: invalid length %d\n", reg, len);
964 		return (USB_ERR_INVAL);
965 	} else if (err)
966 		device_printf(sc->sc_dev, "Reading register %d failed: %s\n", reg, usbd_errstr(err));
967 	return (err);
968 }
969 
970 static usb_error_t
971 umcs7840_set_reg_sync(struct umcs7840_softc *sc, uint8_t reg, uint8_t data)
972 {
973 	struct usb_device_request req;
974 	usb_error_t err;
975 
976 	req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
977 	req.bRequest = MCS7840_WRREQ;
978 	USETW(req.wValue, data);
979 	USETW(req.wIndex, reg);
980 	USETW(req.wLength, 0);
981 
982 	err = usbd_do_request_proc(sc->sc_udev, &sc->sc_super_ucom.sc_tq, &req, NULL, 0, NULL, UMCS7840_CTRL_TIMEOUT);
983 	if (err)
984 		device_printf(sc->sc_dev, "Writing register %d failed: %s\n", reg, usbd_errstr(err));
985 
986 	return (err);
987 }
988 
989 static usb_error_t
990 umcs7840_get_UART_reg_sync(struct umcs7840_softc *sc, uint8_t portno, uint8_t reg, uint8_t *data)
991 {
992 	struct usb_device_request req;
993 	uint16_t wVal;
994 	usb_error_t err;
995 	uint16_t len;
996 
997 	/* portno is port number */
998 	wVal = ((uint16_t)(portno + 1)) << 8;
999 
1000 	req.bmRequestType = UT_READ_VENDOR_DEVICE;
1001 	req.bRequest = MCS7840_RDREQ;
1002 	USETW(req.wValue, wVal);
1003 	USETW(req.wIndex, reg);
1004 	USETW(req.wLength, UMCS7840_READ_LENGTH);
1005 
1006 	err = usbd_do_request_proc(sc->sc_udev, &sc->sc_super_ucom.sc_tq, &req, (void *)data, 0, &len, UMCS7840_CTRL_TIMEOUT);
1007 	if (err == USB_ERR_NORMAL_COMPLETION && len != 1) {
1008 		device_printf(sc->sc_dev, "Reading UART%d register %d failed: invalid length %d\n", portno, reg, len);
1009 		return (USB_ERR_INVAL);
1010 	} else if (err)
1011 		device_printf(sc->sc_dev, "Reading UART%d register %d failed: %s\n", portno, reg, usbd_errstr(err));
1012 	return (err);
1013 }
1014 
1015 static usb_error_t
1016 umcs7840_set_UART_reg_sync(struct umcs7840_softc *sc, uint8_t portno, uint8_t reg, uint8_t data)
1017 {
1018 	struct usb_device_request req;
1019 	usb_error_t err;
1020 	uint16_t wVal;
1021 
1022 	/* portno is port number */
1023 	wVal = ((uint16_t)(portno + 1)) << 8 | data;
1024 
1025 	req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
1026 	req.bRequest = MCS7840_WRREQ;
1027 	USETW(req.wValue, wVal);
1028 	USETW(req.wIndex, reg);
1029 	USETW(req.wLength, 0);
1030 
1031 	err = usbd_do_request_proc(sc->sc_udev, &sc->sc_super_ucom.sc_tq, &req, NULL, 0, NULL, UMCS7840_CTRL_TIMEOUT);
1032 	if (err)
1033 		device_printf(sc->sc_dev, "Writing UART%d register %d failed: %s\n", portno, reg, usbd_errstr(err));
1034 	return (err);
1035 }
1036 
1037 static usb_error_t
1038 umcs7840_set_baudrate(struct umcs7840_softc *sc, uint8_t portno, uint32_t rate)
1039 {
1040 	usb_error_t err;
1041 	uint16_t divisor;
1042 	uint8_t clk;
1043 	uint8_t data;
1044 
1045 	if (umcs7840_calc_baudrate(rate, &divisor, &clk)) {
1046 		DPRINTF("Port %d bad speed: %d\n", portno, rate);
1047 		return (-1);
1048 	}
1049 	if (divisor == 0 || (clk & MCS7840_DEV_SPx_CLOCK_MASK) != clk) {
1050 		DPRINTF("Port %d bad speed calculation: %d\n", portno, rate);
1051 		return (-1);
1052 	}
1053 	DPRINTF("Port %d set speed: %d (%02x / %d)\n", portno, rate, clk, divisor);
1054 
1055 	/* Set clock source for standard BAUD frequences */
1056 	err = umcs7840_get_reg_sync(sc, umcs7840_port_registers[portno].reg_sp, &data);
1057 	if (err)
1058 		return (err);
1059 	data &= MCS7840_DEV_SPx_CLOCK_MASK;
1060 	data |= clk;
1061 	err = umcs7840_set_reg_sync(sc, umcs7840_port_registers[portno].reg_sp, data);
1062 	if (err)
1063 		return (err);
1064 
1065 	/* Set divider */
1066 	sc->sc_ports[portno].sc_lcr |= MCS7840_UART_LCR_DIVISORS;
1067 	err = umcs7840_set_UART_reg_sync(sc, portno, MCS7840_UART_REG_LCR, sc->sc_ports[portno].sc_lcr);
1068 	if (err)
1069 		return (err);
1070 
1071 	err = umcs7840_set_UART_reg_sync(sc, portno, MCS7840_UART_REG_DLL, (uint8_t)(divisor & 0xff));
1072 	if (err)
1073 		return (err);
1074 	err = umcs7840_set_UART_reg_sync(sc, portno, MCS7840_UART_REG_DLM, (uint8_t)((divisor >> 8) & 0xff));
1075 	if (err)
1076 		return (err);
1077 
1078 	/* Turn off access to DLL/DLM registers of UART */
1079 	sc->sc_ports[portno].sc_lcr &= ~MCS7840_UART_LCR_DIVISORS;
1080 	err = umcs7840_set_UART_reg_sync(sc, portno, MCS7840_UART_REG_LCR, sc->sc_ports[portno].sc_lcr);
1081 	if (err)
1082 		return (err);
1083 	return (0);
1084 }
1085 
1086 /* Maximum speeds for standard frequences, when PLL is not used */
1087 static const uint32_t umcs7840_baudrate_divisors[] = {0, 115200, 230400, 403200, 460800, 806400, 921600, 1572864, 3145728,};
1088 static const uint8_t umcs7840_baudrate_divisors_len = nitems(umcs7840_baudrate_divisors);
1089 
1090 static usb_error_t
1091 umcs7840_calc_baudrate(uint32_t rate, uint16_t *divisor, uint8_t *clk)
1092 {
1093 	uint8_t i = 0;
1094 
1095 	if (rate > umcs7840_baudrate_divisors[umcs7840_baudrate_divisors_len - 1])
1096 		return (-1);
1097 
1098 	for (i = 0; i < umcs7840_baudrate_divisors_len - 1 &&
1099 	    !(rate > umcs7840_baudrate_divisors[i] && rate <= umcs7840_baudrate_divisors[i + 1]); ++i);
1100 	if (rate == 0)
1101 		*divisor = 1;	/* XXX */
1102 	else
1103 		*divisor = umcs7840_baudrate_divisors[i + 1] / rate;
1104 	/* 0x00 .. 0x70 */
1105 	*clk = i << MCS7840_DEV_SPx_CLOCK_SHIFT;
1106 	return (0);
1107 }
1108