xref: /freebsd/sys/dev/usb/serial/umcs.c (revision b740c88bfb6453416926271c089262e7164dace3)
1 /*-
2  * Copyright (c) 2010 Lev Serebryakov <lev@FreeBSD.org>.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 /*
28  * This driver supports several multiport USB-to-RS232 serial adapters driven
29  * by MosChip mos7820 and mos7840, bridge chips.
30  * The adapters are sold under many different brand names.
31  *
32  * Datasheets are available at MosChip www site at
33  * http://www.moschip.com.  The datasheets don't contain full
34  * programming information for the chip.
35  *
36  * It is nornal to have only two enabled ports in devices, based on
37  * quad-port mos7840.
38  *
39  */
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 #include <sys/stdint.h>
44 #include <sys/stddef.h>
45 #include <sys/param.h>
46 #include <sys/queue.h>
47 #include <sys/types.h>
48 #include <sys/systm.h>
49 #include <sys/kernel.h>
50 #include <sys/bus.h>
51 #include <sys/linker_set.h>
52 #include <sys/module.h>
53 #include <sys/lock.h>
54 #include <sys/mutex.h>
55 #include <sys/condvar.h>
56 #include <sys/sysctl.h>
57 #include <sys/sx.h>
58 #include <sys/unistd.h>
59 #include <sys/callout.h>
60 #include <sys/malloc.h>
61 #include <sys/priv.h>
62 
63 #include <dev/usb/usb.h>
64 #include <dev/usb/usbdi.h>
65 #include <dev/usb/usbdi_util.h>
66 #include <dev/usb/usb_cdc.h>
67 #include "usbdevs.h"
68 
69 #define	USB_DEBUG_VAR umcs_debug
70 #include <dev/usb/usb_debug.h>
71 #include <dev/usb/usb_process.h>
72 
73 #include <dev/usb/serial/usb_serial.h>
74 
75 #include <dev/usb/serial/umcs.h>
76 
77 #define	UMCS7840_MODVER	1
78 
79 #ifdef USB_DEBUG
80 static int umcs_debug = 0;
81 
82 static SYSCTL_NODE(_hw_usb, OID_AUTO, umcs, CTLFLAG_RW, 0, "USB umcs quadport serial adapter");
83 SYSCTL_INT(_hw_usb_umcs, OID_AUTO, debug, CTLFLAG_RWTUN, &umcs_debug, 0, "Debug level");
84 #endif					/* USB_DEBUG */
85 
86 
87 /*
88  * Two-port devices (both with 7820 chip and 7840 chip configured as two-port)
89  * have ports 0 and 2, with ports 1 and 3 omitted.
90  * So,PHYSICAL port numbers (indexes) on two-port device will be 0 and 2.
91  * This driver trys to use physical numbers as much as possible.
92  */
93 
94 /*
95  * Indexed by PHYSICAL port number.
96  * Pack non-regular registers to array to easier if-less access.
97  */
98 struct umcs7840_port_registers {
99 	uint8_t	reg_sp;			/* SP register. */
100 	uint8_t	reg_control;		/* CONTROL register. */
101 	uint8_t	reg_dcr;		/* DCR0 register. DCR1 & DCR2 can be
102 					 * calculated */
103 };
104 
105 static const struct umcs7840_port_registers umcs7840_port_registers[UMCS7840_MAX_PORTS] = {
106 	{.reg_sp = MCS7840_DEV_REG_SP1,.reg_control = MCS7840_DEV_REG_CONTROL1,.reg_dcr = MCS7840_DEV_REG_DCR0_1},
107 	{.reg_sp = MCS7840_DEV_REG_SP2,.reg_control = MCS7840_DEV_REG_CONTROL2,.reg_dcr = MCS7840_DEV_REG_DCR0_2},
108 	{.reg_sp = MCS7840_DEV_REG_SP3,.reg_control = MCS7840_DEV_REG_CONTROL3,.reg_dcr = MCS7840_DEV_REG_DCR0_3},
109 	{.reg_sp = MCS7840_DEV_REG_SP4,.reg_control = MCS7840_DEV_REG_CONTROL4,.reg_dcr = MCS7840_DEV_REG_DCR0_4},
110 };
111 
112 enum {
113 	UMCS7840_BULK_RD_EP,
114 	UMCS7840_BULK_WR_EP,
115 	UMCS7840_N_TRANSFERS
116 };
117 
118 struct umcs7840_softc_oneport {
119 	struct usb_xfer *sc_xfer[UMCS7840_N_TRANSFERS];	/* Control structures
120 							 * for two transfers */
121 
122 	uint8_t	sc_lcr;			/* local line control register */
123 	uint8_t	sc_mcr;			/* local modem control register */
124 };
125 
126 struct umcs7840_softc {
127 	struct ucom_super_softc sc_super_ucom;
128 	struct ucom_softc sc_ucom[UMCS7840_MAX_PORTS];	/* Need to be continuous
129 							 * array, so indexed by
130 							 * LOGICAL port
131 							 * (subunit) number */
132 
133 	struct usb_xfer *sc_intr_xfer;	/* Interrupt endpoint */
134 
135 	device_t sc_dev;		/* Device for error prints */
136 	struct usb_device *sc_udev;	/* USB Device for all operations */
137 	struct mtx sc_mtx;		/* ucom requires this */
138 
139 	uint8_t	sc_driver_done;		/* Flag when enumeration is finished */
140 
141 	uint8_t	sc_numports;		/* Number of ports (subunits) */
142 	struct umcs7840_softc_oneport sc_ports[UMCS7840_MAX_PORTS];	/* Indexed by PHYSICAL
143 									 * port number. */
144 };
145 
146 /* prototypes */
147 static usb_error_t umcs7840_get_reg_sync(struct umcs7840_softc *, uint8_t, uint8_t *);
148 static usb_error_t umcs7840_set_reg_sync(struct umcs7840_softc *, uint8_t, uint8_t);
149 static usb_error_t umcs7840_get_UART_reg_sync(struct umcs7840_softc *, uint8_t, uint8_t, uint8_t *);
150 static usb_error_t umcs7840_set_UART_reg_sync(struct umcs7840_softc *, uint8_t, uint8_t, uint8_t);
151 
152 static usb_error_t umcs7840_set_baudrate(struct umcs7840_softc *, uint8_t, uint32_t);
153 static usb_error_t umcs7840_calc_baudrate(uint32_t rate, uint16_t *, uint8_t *);
154 
155 static void	umcs7840_free(struct ucom_softc *);
156 static void umcs7840_cfg_get_status(struct ucom_softc *, uint8_t *, uint8_t *);
157 static void umcs7840_cfg_set_dtr(struct ucom_softc *, uint8_t);
158 static void umcs7840_cfg_set_rts(struct ucom_softc *, uint8_t);
159 static void umcs7840_cfg_set_break(struct ucom_softc *, uint8_t);
160 static void umcs7840_cfg_param(struct ucom_softc *, struct termios *);
161 static void umcs7840_cfg_open(struct ucom_softc *);
162 static void umcs7840_cfg_close(struct ucom_softc *);
163 
164 static int umcs7840_pre_param(struct ucom_softc *, struct termios *);
165 
166 static void umcs7840_start_read(struct ucom_softc *);
167 static void umcs7840_stop_read(struct ucom_softc *);
168 
169 static void umcs7840_start_write(struct ucom_softc *);
170 static void umcs7840_stop_write(struct ucom_softc *);
171 
172 static void umcs7840_poll(struct ucom_softc *ucom);
173 
174 static device_probe_t umcs7840_probe;
175 static device_attach_t umcs7840_attach;
176 static device_detach_t umcs7840_detach;
177 static void umcs7840_free_softc(struct umcs7840_softc *);
178 
179 static usb_callback_t umcs7840_intr_callback;
180 static usb_callback_t umcs7840_read_callback1;
181 static usb_callback_t umcs7840_read_callback2;
182 static usb_callback_t umcs7840_read_callback3;
183 static usb_callback_t umcs7840_read_callback4;
184 static usb_callback_t umcs7840_write_callback1;
185 static usb_callback_t umcs7840_write_callback2;
186 static usb_callback_t umcs7840_write_callback3;
187 static usb_callback_t umcs7840_write_callback4;
188 
189 static void umcs7840_read_callbackN(struct usb_xfer *, usb_error_t, uint8_t);
190 static void umcs7840_write_callbackN(struct usb_xfer *, usb_error_t, uint8_t);
191 
192 /* Indexed by LOGICAL port number (subunit), so two-port device uses 0 & 1 */
193 static usb_callback_t *umcs7840_rw_callbacks[UMCS7840_MAX_PORTS][UMCS7840_N_TRANSFERS] = {
194 	{&umcs7840_read_callback1, &umcs7840_write_callback1},
195 	{&umcs7840_read_callback2, &umcs7840_write_callback2},
196 	{&umcs7840_read_callback3, &umcs7840_write_callback3},
197 	{&umcs7840_read_callback4, &umcs7840_write_callback4},
198 };
199 
200 static const struct usb_config umcs7840_bulk_config_data[UMCS7840_N_TRANSFERS] = {
201 	[UMCS7840_BULK_RD_EP] = {
202 		.type = UE_BULK,
203 		.endpoint = 0x01,
204 		.direction = UE_DIR_IN,
205 		.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
206 		.bufsize = 0,		/* use wMaxPacketSize */
207 		.callback = &umcs7840_read_callback1,
208 		.if_index = 0,
209 	},
210 
211 	[UMCS7840_BULK_WR_EP] = {
212 		.type = UE_BULK,
213 		.endpoint = 0x02,
214 		.direction = UE_DIR_OUT,
215 		.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
216 		.bufsize = 0,		/* use wMaxPacketSize */
217 		.callback = &umcs7840_write_callback1,
218 		.if_index = 0,
219 	},
220 };
221 
222 static const struct usb_config umcs7840_intr_config_data[1] = {
223 	[0] = {
224 		.type = UE_INTERRUPT,
225 		.endpoint = 0x09,
226 		.direction = UE_DIR_IN,
227 		.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
228 		.bufsize = 0,		/* use wMaxPacketSize */
229 		.callback = &umcs7840_intr_callback,
230 		.if_index = 0,
231 	},
232 };
233 
234 static struct ucom_callback umcs7840_callback = {
235 	.ucom_cfg_get_status = &umcs7840_cfg_get_status,
236 
237 	.ucom_cfg_set_dtr = &umcs7840_cfg_set_dtr,
238 	.ucom_cfg_set_rts = &umcs7840_cfg_set_rts,
239 	.ucom_cfg_set_break = &umcs7840_cfg_set_break,
240 
241 	.ucom_cfg_param = &umcs7840_cfg_param,
242 	.ucom_cfg_open = &umcs7840_cfg_open,
243 	.ucom_cfg_close = &umcs7840_cfg_close,
244 
245 	.ucom_pre_param = &umcs7840_pre_param,
246 
247 	.ucom_start_read = &umcs7840_start_read,
248 	.ucom_stop_read = &umcs7840_stop_read,
249 
250 	.ucom_start_write = &umcs7840_start_write,
251 	.ucom_stop_write = &umcs7840_stop_write,
252 
253 	.ucom_poll = &umcs7840_poll,
254 	.ucom_free = &umcs7840_free,
255 };
256 
257 static const STRUCT_USB_HOST_ID umcs7840_devs[] = {
258 	{USB_VPI(USB_VENDOR_MOSCHIP, USB_PRODUCT_MOSCHIP_MCS7820, 0)},
259 	{USB_VPI(USB_VENDOR_MOSCHIP, USB_PRODUCT_MOSCHIP_MCS7840, 0)},
260 };
261 
262 static device_method_t umcs7840_methods[] = {
263 	DEVMETHOD(device_probe, umcs7840_probe),
264 	DEVMETHOD(device_attach, umcs7840_attach),
265 	DEVMETHOD(device_detach, umcs7840_detach),
266 	DEVMETHOD_END
267 };
268 
269 static devclass_t umcs7840_devclass;
270 
271 static driver_t umcs7840_driver = {
272 	.name = "umcs7840",
273 	.methods = umcs7840_methods,
274 	.size = sizeof(struct umcs7840_softc),
275 };
276 
277 DRIVER_MODULE(umcs7840, uhub, umcs7840_driver, umcs7840_devclass, 0, 0);
278 MODULE_DEPEND(umcs7840, ucom, 1, 1, 1);
279 MODULE_DEPEND(umcs7840, usb, 1, 1, 1);
280 MODULE_VERSION(umcs7840, UMCS7840_MODVER);
281 
282 static int
283 umcs7840_probe(device_t dev)
284 {
285 	struct usb_attach_arg *uaa = device_get_ivars(dev);
286 
287 	if (uaa->usb_mode != USB_MODE_HOST)
288 		return (ENXIO);
289 	if (uaa->info.bConfigIndex != MCS7840_CONFIG_INDEX)
290 		return (ENXIO);
291 	if (uaa->info.bIfaceIndex != MCS7840_IFACE_INDEX)
292 		return (ENXIO);
293 	return (usbd_lookup_id_by_uaa(umcs7840_devs, sizeof(umcs7840_devs), uaa));
294 }
295 
296 static int
297 umcs7840_attach(device_t dev)
298 {
299 	struct usb_config umcs7840_config_tmp[UMCS7840_N_TRANSFERS];
300 	struct usb_attach_arg *uaa = device_get_ivars(dev);
301 	struct umcs7840_softc *sc = device_get_softc(dev);
302 
303 	uint8_t iface_index = MCS7840_IFACE_INDEX;
304 	int error;
305 	int subunit;
306 	int n;
307 	uint8_t data;
308 
309 	for (n = 0; n < UMCS7840_N_TRANSFERS; ++n)
310 		umcs7840_config_tmp[n] = umcs7840_bulk_config_data[n];
311 
312 	device_set_usb_desc(dev);
313 	mtx_init(&sc->sc_mtx, "umcs7840", NULL, MTX_DEF);
314 	ucom_ref(&sc->sc_super_ucom);
315 
316 	sc->sc_dev = dev;
317 	sc->sc_udev = uaa->device;
318 
319 	/*
320 	 * Get number of ports
321 	 * Documentation (full datasheet) says, that number of ports is
322 	 * set as MCS7840_DEV_MODE_SELECT24S bit in MODE R/Only
323 	 * register. But vendor driver uses these undocumented
324 	 * register & bit.
325 	 *
326 	 * Experiments show, that MODE register can have `0'
327 	 * (4 ports) bit on 2-port device, so use vendor driver's way.
328 	 *
329 	 * Also, see notes in header file for these constants.
330 	 */
331 	umcs7840_get_reg_sync(sc, MCS7840_DEV_REG_GPIO, &data);
332 	if (data & MCS7840_DEV_GPIO_4PORTS) {
333 		sc->sc_numports = 4;
334 		/* Store physical port numbers in sc_portno */
335 		sc->sc_ucom[0].sc_portno = 0;
336 		sc->sc_ucom[1].sc_portno = 1;
337 		sc->sc_ucom[2].sc_portno = 2;
338 		sc->sc_ucom[3].sc_portno = 3;
339 	} else {
340 		sc->sc_numports = 2;
341 		/* Store physical port numbers in sc_portno */
342 		sc->sc_ucom[0].sc_portno = 0;
343 		sc->sc_ucom[1].sc_portno = 2;	/* '1' is skipped */
344 	}
345 	device_printf(dev, "Chip mcs%04x, found %d active ports\n", uaa->info.idProduct, sc->sc_numports);
346 	if (!umcs7840_get_reg_sync(sc, MCS7840_DEV_REG_MODE, &data)) {
347 		device_printf(dev, "On-die confguration: RST: active %s, HRD: %s, PLL: %s, POR: %s, Ports: %s, EEPROM write %s, IrDA is %savailable\n",
348 		    (data & MCS7840_DEV_MODE_RESET) ? "low" : "high",
349 		    (data & MCS7840_DEV_MODE_SER_PRSNT) ? "yes" : "no",
350 		    (data & MCS7840_DEV_MODE_PLLBYPASS) ? "bypassed" : "avail",
351 		    (data & MCS7840_DEV_MODE_PORBYPASS) ? "bypassed" : "avail",
352 		    (data & MCS7840_DEV_MODE_SELECT24S) ? "2" : "4",
353 		    (data & MCS7840_DEV_MODE_EEPROMWR) ? "enabled" : "disabled",
354 		    (data & MCS7840_DEV_MODE_IRDA) ? "" : "not ");
355 	}
356 	/* Setup all transfers */
357 	for (subunit = 0; subunit < sc->sc_numports; ++subunit) {
358 		for (n = 0; n < UMCS7840_N_TRANSFERS; ++n) {
359 			/* Set endpoint address */
360 			umcs7840_config_tmp[n].endpoint = umcs7840_bulk_config_data[n].endpoint + 2 * sc->sc_ucom[subunit].sc_portno;
361 			umcs7840_config_tmp[n].callback = umcs7840_rw_callbacks[subunit][n];
362 		}
363 		error = usbd_transfer_setup(uaa->device,
364 		    &iface_index, sc->sc_ports[sc->sc_ucom[subunit].sc_portno].sc_xfer, umcs7840_config_tmp,
365 		    UMCS7840_N_TRANSFERS, sc, &sc->sc_mtx);
366 		if (error) {
367 			device_printf(dev, "allocating USB transfers failed for subunit %d of %d\n",
368 			    subunit + 1, sc->sc_numports);
369 			goto detach;
370 		}
371 	}
372 	error = usbd_transfer_setup(uaa->device,
373 	    &iface_index, &sc->sc_intr_xfer, umcs7840_intr_config_data,
374 	    1, sc, &sc->sc_mtx);
375 	if (error) {
376 		device_printf(dev, "allocating USB transfers failed for interrupt\n");
377 		goto detach;
378 	}
379 	/* clear stall at first run */
380 	mtx_lock(&sc->sc_mtx);
381 	for (subunit = 0; subunit < sc->sc_numports; ++subunit) {
382 		usbd_xfer_set_stall(sc->sc_ports[sc->sc_ucom[subunit].sc_portno].sc_xfer[UMCS7840_BULK_RD_EP]);
383 		usbd_xfer_set_stall(sc->sc_ports[sc->sc_ucom[subunit].sc_portno].sc_xfer[UMCS7840_BULK_WR_EP]);
384 	}
385 	mtx_unlock(&sc->sc_mtx);
386 
387 	error = ucom_attach(&sc->sc_super_ucom, sc->sc_ucom, sc->sc_numports, sc,
388 	    &umcs7840_callback, &sc->sc_mtx);
389 	if (error)
390 		goto detach;
391 
392 	ucom_set_pnpinfo_usb(&sc->sc_super_ucom, dev);
393 
394 	return (0);
395 
396 detach:
397 	umcs7840_detach(dev);
398 	return (ENXIO);
399 }
400 
401 static int
402 umcs7840_detach(device_t dev)
403 {
404 	struct umcs7840_softc *sc = device_get_softc(dev);
405 	int subunit;
406 
407 	ucom_detach(&sc->sc_super_ucom, sc->sc_ucom);
408 
409 	for (subunit = 0; subunit < sc->sc_numports; ++subunit)
410 		usbd_transfer_unsetup(sc->sc_ports[sc->sc_ucom[subunit].sc_portno].sc_xfer, UMCS7840_N_TRANSFERS);
411 	usbd_transfer_unsetup(&sc->sc_intr_xfer, 1);
412 
413 	device_claim_softc(dev);
414 
415 	umcs7840_free_softc(sc);
416 
417 	return (0);
418 }
419 
420 UCOM_UNLOAD_DRAIN(umcs7840);
421 
422 static void
423 umcs7840_free_softc(struct umcs7840_softc *sc)
424 {
425 	if (ucom_unref(&sc->sc_super_ucom)) {
426 		mtx_destroy(&sc->sc_mtx);
427 		device_free_softc(sc);
428 	}
429 }
430 
431 static void
432 umcs7840_free(struct ucom_softc *ucom)
433 {
434 	umcs7840_free_softc(ucom->sc_parent);
435 }
436 
437 static void
438 umcs7840_cfg_open(struct ucom_softc *ucom)
439 {
440 	struct umcs7840_softc *sc = ucom->sc_parent;
441 	uint16_t pn = ucom->sc_portno;
442 	uint8_t data;
443 
444 	/* If it very first open, finish global configuration */
445 	if (!sc->sc_driver_done) {
446 		/*
447 		 * USB enumeration is finished, pass internal memory to FIFOs
448 		 * If it is done in the end of "attach", kernel panics.
449 		 */
450 		if (umcs7840_get_reg_sync(sc, MCS7840_DEV_REG_CONTROL1, &data))
451 			return;
452 		data |= MCS7840_DEV_CONTROL1_DRIVER_DONE;
453 		if (umcs7840_set_reg_sync(sc, MCS7840_DEV_REG_CONTROL1, data))
454 			return;
455 		sc->sc_driver_done = 1;
456 	}
457 	/* Toggle reset bit on-off */
458 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, &data))
459 		return;
460 	data |= MCS7840_DEV_SPx_UART_RESET;
461 	if (umcs7840_set_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 
467 	/* Set RS-232 mode */
468 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_SCRATCHPAD, MCS7840_UART_SCRATCHPAD_RS232))
469 		return;
470 
471 	/* Disable RX on time of initialization */
472 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_control, &data))
473 		return;
474 	data |= MCS7840_DEV_CONTROLx_RX_DISABLE;
475 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_control, data))
476 		return;
477 
478 	/* Disable all interrupts */
479 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_IER, 0))
480 		return;
481 
482 	/* Reset FIFO -- documented */
483 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_FCR, 0))
484 		return;
485 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_FCR,
486 	    MCS7840_UART_FCR_ENABLE | MCS7840_UART_FCR_FLUSHRHR |
487 	    MCS7840_UART_FCR_FLUSHTHR | MCS7840_UART_FCR_RTL_1_14))
488 		return;
489 
490 	/* Set 8 bit, no parity, 1 stop bit -- documented */
491 	sc->sc_ports[pn].sc_lcr = MCS7840_UART_LCR_DATALEN8 | MCS7840_UART_LCR_STOPB1;
492 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_LCR, sc->sc_ports[pn].sc_lcr))
493 		return;
494 
495 	/*
496 	 * Enable DTR/RTS on modem control, enable modem interrupts --
497 	 * documented
498 	 */
499 	sc->sc_ports[pn].sc_mcr = MCS7840_UART_MCR_DTR | MCS7840_UART_MCR_RTS | MCS7840_UART_MCR_IE;
500 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, sc->sc_ports[pn].sc_mcr))
501 		return;
502 
503 	/* Clearing Bulkin and Bulkout FIFO */
504 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, &data))
505 		return;
506 	data |= MCS7840_DEV_SPx_RESET_OUT_FIFO | MCS7840_DEV_SPx_RESET_IN_FIFO;
507 	if (umcs7840_set_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 
513 	/* Set speed 9600 */
514 	if (umcs7840_set_baudrate(sc, pn, 9600))
515 		return;
516 
517 
518 	/* Finally enable all interrupts -- documented */
519 	/*
520 	 * Copied from vendor driver, I don't know why we should read LCR
521 	 * here
522 	 */
523 	if (umcs7840_get_UART_reg_sync(sc, pn, MCS7840_UART_REG_LCR, &sc->sc_ports[pn].sc_lcr))
524 		return;
525 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_IER,
526 	    MCS7840_UART_IER_RXSTAT | MCS7840_UART_IER_MODEM))
527 		return;
528 
529 	/* Enable RX */
530 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_control, &data))
531 		return;
532 	data &= ~MCS7840_DEV_CONTROLx_RX_DISABLE;
533 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_control, data))
534 		return;
535 
536 	DPRINTF("Port %d has been opened\n", pn);
537 }
538 
539 static void
540 umcs7840_cfg_close(struct ucom_softc *ucom)
541 {
542 	struct umcs7840_softc *sc = ucom->sc_parent;
543 	uint16_t pn = ucom->sc_portno;
544 	uint8_t data;
545 
546 	umcs7840_stop_read(ucom);
547 	umcs7840_stop_write(ucom);
548 
549 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, 0);
550 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_IER, 0);
551 
552 	/* Disable RX */
553 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_control, &data))
554 		return;
555 	data |= MCS7840_DEV_CONTROLx_RX_DISABLE;
556 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_control, data))
557 		return;
558 	DPRINTF("Port %d has been closed\n", pn);
559 }
560 
561 static void
562 umcs7840_cfg_set_dtr(struct ucom_softc *ucom, uint8_t onoff)
563 {
564 	struct umcs7840_softc *sc = ucom->sc_parent;
565 	uint8_t pn = ucom->sc_portno;
566 
567 	if (onoff)
568 		sc->sc_ports[pn].sc_mcr |= MCS7840_UART_MCR_DTR;
569 	else
570 		sc->sc_ports[pn].sc_mcr &= ~MCS7840_UART_MCR_DTR;
571 
572 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, sc->sc_ports[pn].sc_mcr);
573 	DPRINTF("Port %d DTR set to: %s\n", pn, onoff ? "on" : "off");
574 }
575 
576 static void
577 umcs7840_cfg_set_rts(struct ucom_softc *ucom, uint8_t onoff)
578 {
579 	struct umcs7840_softc *sc = ucom->sc_parent;
580 	uint8_t pn = ucom->sc_portno;
581 
582 	if (onoff)
583 		sc->sc_ports[pn].sc_mcr |= MCS7840_UART_MCR_RTS;
584 	else
585 		sc->sc_ports[pn].sc_mcr &= ~MCS7840_UART_MCR_RTS;
586 
587 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, sc->sc_ports[pn].sc_mcr);
588 	DPRINTF("Port %d RTS set to: %s\n", pn, onoff ? "on" : "off");
589 }
590 
591 static void
592 umcs7840_cfg_set_break(struct ucom_softc *ucom, uint8_t onoff)
593 {
594 	struct umcs7840_softc *sc = ucom->sc_parent;
595 	uint8_t pn = ucom->sc_portno;
596 
597 	if (onoff)
598 		sc->sc_ports[pn].sc_lcr |= MCS7840_UART_LCR_BREAK;
599 	else
600 		sc->sc_ports[pn].sc_lcr &= ~MCS7840_UART_LCR_BREAK;
601 
602 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_LCR, sc->sc_ports[pn].sc_lcr);
603 	DPRINTF("Port %d BREAK set to: %s\n", pn, onoff ? "on" : "off");
604 }
605 
606 
607 static void
608 umcs7840_cfg_param(struct ucom_softc *ucom, struct termios *t)
609 {
610 	struct umcs7840_softc *sc = ucom->sc_parent;
611 	uint8_t pn = ucom->sc_portno;
612 	uint8_t lcr = sc->sc_ports[pn].sc_lcr;
613 	uint8_t mcr = sc->sc_ports[pn].sc_mcr;
614 
615 	DPRINTF("Port %d config:\n", pn);
616 	if (t->c_cflag & CSTOPB) {
617 		DPRINTF("  2 stop bits\n");
618 		lcr |= MCS7840_UART_LCR_STOPB2;
619 	} else {
620 		lcr |= MCS7840_UART_LCR_STOPB1;
621 		DPRINTF("  1 stop bit\n");
622 	}
623 
624 	lcr &= ~MCS7840_UART_LCR_PARITYMASK;
625 	if (t->c_cflag & PARENB) {
626 		lcr |= MCS7840_UART_LCR_PARITYON;
627 		if (t->c_cflag & PARODD) {
628 			lcr = MCS7840_UART_LCR_PARITYODD;
629 			DPRINTF("  parity on - odd\n");
630 		} else {
631 			lcr = MCS7840_UART_LCR_PARITYEVEN;
632 			DPRINTF("  parity on - even\n");
633 		}
634 	} else {
635 		lcr &= ~MCS7840_UART_LCR_PARITYON;
636 		DPRINTF("  parity off\n");
637 	}
638 
639 	lcr &= ~MCS7840_UART_LCR_DATALENMASK;
640 	switch (t->c_cflag & CSIZE) {
641 	case CS5:
642 		lcr |= MCS7840_UART_LCR_DATALEN5;
643 		DPRINTF("  5 bit\n");
644 		break;
645 	case CS6:
646 		lcr |= MCS7840_UART_LCR_DATALEN6;
647 		DPRINTF("  6 bit\n");
648 		break;
649 	case CS7:
650 		lcr |= MCS7840_UART_LCR_DATALEN7;
651 		DPRINTF("  7 bit\n");
652 		break;
653 	case CS8:
654 		lcr |= MCS7840_UART_LCR_DATALEN8;
655 		DPRINTF("  8 bit\n");
656 		break;
657 	}
658 
659 	if (t->c_cflag & CRTSCTS) {
660 		mcr |= MCS7840_UART_MCR_CTSRTS;
661 		DPRINTF("  CTS/RTS\n");
662 	} else
663 		mcr &= ~MCS7840_UART_MCR_CTSRTS;
664 
665 	if (t->c_cflag & (CDTR_IFLOW | CDSR_OFLOW)) {
666 		mcr |= MCS7840_UART_MCR_DTRDSR;
667 		DPRINTF("  DTR/DSR\n");
668 	} else
669 		mcr &= ~MCS7840_UART_MCR_DTRDSR;
670 
671 	sc->sc_ports[pn].sc_lcr = lcr;
672 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_LCR, sc->sc_ports[pn].sc_lcr);
673 	DPRINTF("Port %d LCR=%02x\n", pn, sc->sc_ports[pn].sc_lcr);
674 
675 	sc->sc_ports[pn].sc_mcr = mcr;
676 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, sc->sc_ports[pn].sc_mcr);
677 	DPRINTF("Port %d MCR=%02x\n", pn, sc->sc_ports[pn].sc_mcr);
678 
679 	umcs7840_set_baudrate(sc, pn, t->c_ospeed);
680 }
681 
682 
683 static int
684 umcs7840_pre_param(struct ucom_softc *ucom, struct termios *t)
685 {
686 	uint8_t clk;
687 	uint16_t divisor;
688 
689 	if (umcs7840_calc_baudrate(t->c_ospeed, &divisor, &clk) || !divisor)
690 		return (EINVAL);
691 	return (0);
692 }
693 
694 static void
695 umcs7840_start_read(struct ucom_softc *ucom)
696 {
697 	struct umcs7840_softc *sc = ucom->sc_parent;
698 	uint8_t pn = ucom->sc_portno;
699 
700 	/* Start interrupt transfer */
701 	usbd_transfer_start(sc->sc_intr_xfer);
702 
703 	/* Start read transfer */
704 	usbd_transfer_start(sc->sc_ports[pn].sc_xfer[UMCS7840_BULK_RD_EP]);
705 }
706 
707 static void
708 umcs7840_stop_read(struct ucom_softc *ucom)
709 {
710 	struct umcs7840_softc *sc = ucom->sc_parent;
711 	uint8_t pn = ucom->sc_portno;
712 
713 	/* Stop read transfer */
714 	usbd_transfer_stop(sc->sc_ports[pn].sc_xfer[UMCS7840_BULK_RD_EP]);
715 }
716 
717 static void
718 umcs7840_start_write(struct ucom_softc *ucom)
719 {
720 	struct umcs7840_softc *sc = ucom->sc_parent;
721 	uint8_t pn = ucom->sc_portno;
722 
723 	/* Start interrupt transfer */
724 	usbd_transfer_start(sc->sc_intr_xfer);
725 
726 	/* Start write transfer */
727 	usbd_transfer_start(sc->sc_ports[pn].sc_xfer[UMCS7840_BULK_WR_EP]);
728 }
729 
730 static void
731 umcs7840_stop_write(struct ucom_softc *ucom)
732 {
733 	struct umcs7840_softc *sc = ucom->sc_parent;
734 	uint8_t pn = ucom->sc_portno;
735 
736 	/* Stop write transfer */
737 	usbd_transfer_stop(sc->sc_ports[pn].sc_xfer[UMCS7840_BULK_WR_EP]);
738 }
739 
740 static void
741 umcs7840_cfg_get_status(struct ucom_softc *ucom, uint8_t *lsr, uint8_t *msr)
742 {
743 	struct umcs7840_softc *sc = ucom->sc_parent;
744 	uint8_t pn = ucom->sc_portno;
745 	uint8_t	hw_lsr = 0;	/* local line status register */
746 	uint8_t	hw_msr = 0;	/* local modem status register */
747 
748 	/* Read LSR & MSR */
749 	umcs7840_get_UART_reg_sync(sc, pn, MCS7840_UART_REG_LSR, &hw_lsr);
750 	umcs7840_get_UART_reg_sync(sc, pn, MCS7840_UART_REG_MSR, &hw_msr);
751 
752 	*lsr = hw_lsr;
753 	*msr = hw_msr;
754 
755 	DPRINTF("Port %d status: LSR=%02x MSR=%02x\n", ucom->sc_portno, *lsr, *msr);
756 }
757 
758 static void
759 umcs7840_intr_callback(struct usb_xfer *xfer, usb_error_t error)
760 {
761 	struct umcs7840_softc *sc = usbd_xfer_softc(xfer);
762 	struct usb_page_cache *pc;
763 	uint8_t buf[13];
764 	int actlen;
765 	int subunit;
766 
767 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
768 
769 	switch (USB_GET_STATE(xfer)) {
770 	case USB_ST_TRANSFERRED:
771 		if (actlen == 5 || actlen == 13) {
772 			pc = usbd_xfer_get_frame(xfer, 0);
773 			usbd_copy_out(pc, 0, buf, actlen);
774 			/* Check status of all ports */
775 			for (subunit = 0; subunit < sc->sc_numports; ++subunit) {
776 				uint8_t pn = sc->sc_ucom[subunit].sc_portno;
777 
778 				if (buf[pn] & MCS7840_UART_ISR_NOPENDING)
779 					continue;
780 				DPRINTF("Port %d has pending interrupt: %02x (FIFO: %02x)\n", pn, buf[pn] & MCS7840_UART_ISR_INTMASK, buf[pn] & (~MCS7840_UART_ISR_INTMASK));
781 				switch (buf[pn] & MCS7840_UART_ISR_INTMASK) {
782 				case MCS7840_UART_ISR_RXERR:
783 				case MCS7840_UART_ISR_RXHASDATA:
784 				case MCS7840_UART_ISR_RXTIMEOUT:
785 				case MCS7840_UART_ISR_MSCHANGE:
786 					ucom_status_change(&sc->sc_ucom[subunit]);
787 					break;
788 				default:
789 					/* Do nothing */
790 					break;
791 				}
792 			}
793 		} else
794 			device_printf(sc->sc_dev, "Invalid interrupt data length %d", actlen);
795 		/* FALLTHROUGH */
796 	case USB_ST_SETUP:
797 tr_setup:
798 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
799 		usbd_transfer_submit(xfer);
800 		return;
801 
802 	default:			/* Error */
803 		if (error != USB_ERR_CANCELLED) {
804 			/* try to clear stall first */
805 			usbd_xfer_set_stall(xfer);
806 			goto tr_setup;
807 		}
808 		return;
809 	}
810 }
811 
812 static void
813 umcs7840_read_callback1(struct usb_xfer *xfer, usb_error_t error)
814 {
815 	umcs7840_read_callbackN(xfer, error, 0);
816 }
817 
818 static void
819 umcs7840_read_callback2(struct usb_xfer *xfer, usb_error_t error)
820 {
821 	umcs7840_read_callbackN(xfer, error, 1);
822 }
823 static void
824 umcs7840_read_callback3(struct usb_xfer *xfer, usb_error_t error)
825 {
826 	umcs7840_read_callbackN(xfer, error, 2);
827 }
828 
829 static void
830 umcs7840_read_callback4(struct usb_xfer *xfer, usb_error_t error)
831 {
832 	umcs7840_read_callbackN(xfer, error, 3);
833 }
834 
835 static void
836 umcs7840_read_callbackN(struct usb_xfer *xfer, usb_error_t error, uint8_t subunit)
837 {
838 	struct umcs7840_softc *sc = usbd_xfer_softc(xfer);
839 	struct ucom_softc *ucom = &sc->sc_ucom[subunit];
840 	struct usb_page_cache *pc;
841 	int actlen;
842 
843 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
844 
845 	DPRINTF("Port %d read, state = %d, data length = %d\n", ucom->sc_portno, USB_GET_STATE(xfer), actlen);
846 
847 	switch (USB_GET_STATE(xfer)) {
848 	case USB_ST_TRANSFERRED:
849 		pc = usbd_xfer_get_frame(xfer, 0);
850 		ucom_put_data(ucom, pc, 0, actlen);
851 		/* FALLTHROUGH */
852 	case USB_ST_SETUP:
853 tr_setup:
854 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
855 		usbd_transfer_submit(xfer);
856 		return;
857 
858 	default:			/* Error */
859 		if (error != USB_ERR_CANCELLED) {
860 			/* try to clear stall first */
861 			usbd_xfer_set_stall(xfer);
862 			goto tr_setup;
863 		}
864 		return;
865 	}
866 }
867 
868 static void
869 umcs7840_write_callback1(struct usb_xfer *xfer, usb_error_t error)
870 {
871 	umcs7840_write_callbackN(xfer, error, 0);
872 }
873 
874 static void
875 umcs7840_write_callback2(struct usb_xfer *xfer, usb_error_t error)
876 {
877 	umcs7840_write_callbackN(xfer, error, 1);
878 }
879 
880 static void
881 umcs7840_write_callback3(struct usb_xfer *xfer, usb_error_t error)
882 {
883 	umcs7840_write_callbackN(xfer, error, 2);
884 }
885 
886 static void
887 umcs7840_write_callback4(struct usb_xfer *xfer, usb_error_t error)
888 {
889 	umcs7840_write_callbackN(xfer, error, 3);
890 }
891 
892 static void
893 umcs7840_write_callbackN(struct usb_xfer *xfer, usb_error_t error, uint8_t subunit)
894 {
895 	struct umcs7840_softc *sc = usbd_xfer_softc(xfer);
896 	struct ucom_softc *ucom = &sc->sc_ucom[subunit];
897 	struct usb_page_cache *pc;
898 	uint32_t actlen;
899 
900 	DPRINTF("Port %d write, state = %d\n", ucom->sc_portno, USB_GET_STATE(xfer));
901 
902 	switch (USB_GET_STATE(xfer)) {
903 	case USB_ST_SETUP:
904 	case USB_ST_TRANSFERRED:
905 tr_setup:
906 		pc = usbd_xfer_get_frame(xfer, 0);
907 		if (ucom_get_data(ucom, pc, 0, usbd_xfer_max_len(xfer), &actlen)) {
908 			DPRINTF("Port %d write, has %d bytes\n", ucom->sc_portno, actlen);
909 			usbd_xfer_set_frame_len(xfer, 0, actlen);
910 			usbd_transfer_submit(xfer);
911 		}
912 		return;
913 
914 	default:			/* Error */
915 		if (error != USB_ERR_CANCELLED) {
916 			/* try to clear stall first */
917 			usbd_xfer_set_stall(xfer);
918 			goto tr_setup;
919 		}
920 		return;
921 	}
922 }
923 
924 static void
925 umcs7840_poll(struct ucom_softc *ucom)
926 {
927 	struct umcs7840_softc *sc = ucom->sc_parent;
928 
929 	DPRINTF("Port %d poll\n", ucom->sc_portno);
930 	usbd_transfer_poll(sc->sc_ports[ucom->sc_portno].sc_xfer, UMCS7840_N_TRANSFERS);
931 	usbd_transfer_poll(&sc->sc_intr_xfer, 1);
932 }
933 
934 static usb_error_t
935 umcs7840_get_reg_sync(struct umcs7840_softc *sc, uint8_t reg, uint8_t *data)
936 {
937 	struct usb_device_request req;
938 	usb_error_t err;
939 	uint16_t len;
940 
941 	req.bmRequestType = UT_READ_VENDOR_DEVICE;
942 	req.bRequest = MCS7840_RDREQ;
943 	USETW(req.wValue, 0);
944 	USETW(req.wIndex, reg);
945 	USETW(req.wLength, UMCS7840_READ_LENGTH);
946 
947 	err = usbd_do_request_proc(sc->sc_udev, &sc->sc_super_ucom.sc_tq, &req, (void *)data, 0, &len, UMCS7840_CTRL_TIMEOUT);
948 	if (err == USB_ERR_NORMAL_COMPLETION && len != 1) {
949 		device_printf(sc->sc_dev, "Reading register %d failed: invalid length %d\n", reg, len);
950 		return (USB_ERR_INVAL);
951 	} else if (err)
952 		device_printf(sc->sc_dev, "Reading register %d failed: %s\n", reg, usbd_errstr(err));
953 	return (err);
954 }
955 
956 static usb_error_t
957 umcs7840_set_reg_sync(struct umcs7840_softc *sc, uint8_t reg, uint8_t data)
958 {
959 	struct usb_device_request req;
960 	usb_error_t err;
961 
962 	req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
963 	req.bRequest = MCS7840_WRREQ;
964 	USETW(req.wValue, data);
965 	USETW(req.wIndex, reg);
966 	USETW(req.wLength, 0);
967 
968 	err = usbd_do_request_proc(sc->sc_udev, &sc->sc_super_ucom.sc_tq, &req, NULL, 0, NULL, UMCS7840_CTRL_TIMEOUT);
969 	if (err)
970 		device_printf(sc->sc_dev, "Writing register %d failed: %s\n", reg, usbd_errstr(err));
971 
972 	return (err);
973 }
974 
975 static usb_error_t
976 umcs7840_get_UART_reg_sync(struct umcs7840_softc *sc, uint8_t portno, uint8_t reg, uint8_t *data)
977 {
978 	struct usb_device_request req;
979 	uint16_t wVal;
980 	usb_error_t err;
981 	uint16_t len;
982 
983 	/* portno is port number */
984 	wVal = ((uint16_t)(portno + 1)) << 8;
985 
986 	req.bmRequestType = UT_READ_VENDOR_DEVICE;
987 	req.bRequest = MCS7840_RDREQ;
988 	USETW(req.wValue, wVal);
989 	USETW(req.wIndex, reg);
990 	USETW(req.wLength, UMCS7840_READ_LENGTH);
991 
992 	err = usbd_do_request_proc(sc->sc_udev, &sc->sc_super_ucom.sc_tq, &req, (void *)data, 0, &len, UMCS7840_CTRL_TIMEOUT);
993 	if (err == USB_ERR_NORMAL_COMPLETION && len != 1) {
994 		device_printf(sc->sc_dev, "Reading UART%d register %d failed: invalid length %d\n", portno, reg, len);
995 		return (USB_ERR_INVAL);
996 	} else if (err)
997 		device_printf(sc->sc_dev, "Reading UART%d register %d failed: %s\n", portno, reg, usbd_errstr(err));
998 	return (err);
999 }
1000 
1001 static usb_error_t
1002 umcs7840_set_UART_reg_sync(struct umcs7840_softc *sc, uint8_t portno, uint8_t reg, uint8_t data)
1003 {
1004 	struct usb_device_request req;
1005 	usb_error_t err;
1006 	uint16_t wVal;
1007 
1008 	/* portno is port number */
1009 	wVal = ((uint16_t)(portno + 1)) << 8 | data;
1010 
1011 	req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
1012 	req.bRequest = MCS7840_WRREQ;
1013 	USETW(req.wValue, wVal);
1014 	USETW(req.wIndex, reg);
1015 	USETW(req.wLength, 0);
1016 
1017 	err = usbd_do_request_proc(sc->sc_udev, &sc->sc_super_ucom.sc_tq, &req, NULL, 0, NULL, UMCS7840_CTRL_TIMEOUT);
1018 	if (err)
1019 		device_printf(sc->sc_dev, "Writing UART%d register %d failed: %s\n", portno, reg, usbd_errstr(err));
1020 	return (err);
1021 }
1022 
1023 static usb_error_t
1024 umcs7840_set_baudrate(struct umcs7840_softc *sc, uint8_t portno, uint32_t rate)
1025 {
1026 	usb_error_t err;
1027 	uint16_t divisor;
1028 	uint8_t clk;
1029 	uint8_t data;
1030 
1031 	if (umcs7840_calc_baudrate(rate, &divisor, &clk)) {
1032 		DPRINTF("Port %d bad speed: %d\n", portno, rate);
1033 		return (-1);
1034 	}
1035 	if (divisor == 0 || (clk & MCS7840_DEV_SPx_CLOCK_MASK) != clk) {
1036 		DPRINTF("Port %d bad speed calculation: %d\n", portno, rate);
1037 		return (-1);
1038 	}
1039 	DPRINTF("Port %d set speed: %d (%02x / %d)\n", portno, rate, clk, divisor);
1040 
1041 	/* Set clock source for standard BAUD frequences */
1042 	err = umcs7840_get_reg_sync(sc, umcs7840_port_registers[portno].reg_sp, &data);
1043 	if (err)
1044 		return (err);
1045 	data &= MCS7840_DEV_SPx_CLOCK_MASK;
1046 	data |= clk;
1047 	err = umcs7840_set_reg_sync(sc, umcs7840_port_registers[portno].reg_sp, data);
1048 	if (err)
1049 		return (err);
1050 
1051 	/* Set divider */
1052 	sc->sc_ports[portno].sc_lcr |= MCS7840_UART_LCR_DIVISORS;
1053 	err = umcs7840_set_UART_reg_sync(sc, portno, MCS7840_UART_REG_LCR, sc->sc_ports[portno].sc_lcr);
1054 	if (err)
1055 		return (err);
1056 
1057 	err = umcs7840_set_UART_reg_sync(sc, portno, MCS7840_UART_REG_DLL, (uint8_t)(divisor & 0xff));
1058 	if (err)
1059 		return (err);
1060 	err = umcs7840_set_UART_reg_sync(sc, portno, MCS7840_UART_REG_DLM, (uint8_t)((divisor >> 8) & 0xff));
1061 	if (err)
1062 		return (err);
1063 
1064 	/* Turn off access to DLL/DLM registers of UART */
1065 	sc->sc_ports[portno].sc_lcr &= ~MCS7840_UART_LCR_DIVISORS;
1066 	err = umcs7840_set_UART_reg_sync(sc, portno, MCS7840_UART_REG_LCR, sc->sc_ports[portno].sc_lcr);
1067 	if (err)
1068 		return (err);
1069 	return (0);
1070 }
1071 
1072 /* Maximum speeds for standard frequences, when PLL is not used */
1073 static const uint32_t umcs7840_baudrate_divisors[] = {0, 115200, 230400, 403200, 460800, 806400, 921600, 1572864, 3145728,};
1074 static const uint8_t umcs7840_baudrate_divisors_len = sizeof(umcs7840_baudrate_divisors) / sizeof(umcs7840_baudrate_divisors[0]);
1075 
1076 static usb_error_t
1077 umcs7840_calc_baudrate(uint32_t rate, uint16_t *divisor, uint8_t *clk)
1078 {
1079 	uint8_t i = 0;
1080 
1081 	if (rate > umcs7840_baudrate_divisors[umcs7840_baudrate_divisors_len - 1])
1082 		return (-1);
1083 
1084 	for (i = 0; i < umcs7840_baudrate_divisors_len - 1 &&
1085 	    !(rate > umcs7840_baudrate_divisors[i] && rate <= umcs7840_baudrate_divisors[i + 1]); ++i);
1086 	if (rate == 0)
1087 		*divisor = 1;	/* XXX */
1088 	else
1089 		*divisor = umcs7840_baudrate_divisors[i + 1] / rate;
1090 	/* 0x00 .. 0x70 */
1091 	*clk = i << MCS7840_DEV_SPx_CLOCK_SHIFT;
1092 	return (0);
1093 }
1094