xref: /freebsd/sys/dev/usb/serial/umcs.c (revision cbd30a72ca196976c1c700400ecd424baa1b9c16)
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 USB_PNP_HOST_INFO(umcs7840_devs);
282 
283 static int
284 umcs7840_probe(device_t dev)
285 {
286 	struct usb_attach_arg *uaa = device_get_ivars(dev);
287 
288 	if (uaa->usb_mode != USB_MODE_HOST)
289 		return (ENXIO);
290 	if (uaa->info.bConfigIndex != MCS7840_CONFIG_INDEX)
291 		return (ENXIO);
292 	if (uaa->info.bIfaceIndex != MCS7840_IFACE_INDEX)
293 		return (ENXIO);
294 	return (usbd_lookup_id_by_uaa(umcs7840_devs, sizeof(umcs7840_devs), uaa));
295 }
296 
297 static int
298 umcs7840_attach(device_t dev)
299 {
300 	struct usb_config umcs7840_config_tmp[UMCS7840_N_TRANSFERS];
301 	struct usb_attach_arg *uaa = device_get_ivars(dev);
302 	struct umcs7840_softc *sc = device_get_softc(dev);
303 
304 	uint8_t iface_index = MCS7840_IFACE_INDEX;
305 	int error;
306 	int subunit;
307 	int n;
308 	uint8_t data;
309 
310 	for (n = 0; n < UMCS7840_N_TRANSFERS; ++n)
311 		umcs7840_config_tmp[n] = umcs7840_bulk_config_data[n];
312 
313 	device_set_usb_desc(dev);
314 	mtx_init(&sc->sc_mtx, "umcs7840", NULL, MTX_DEF);
315 	ucom_ref(&sc->sc_super_ucom);
316 
317 	sc->sc_dev = dev;
318 	sc->sc_udev = uaa->device;
319 
320 	/*
321 	 * Get number of ports
322 	 * Documentation (full datasheet) says, that number of ports is
323 	 * set as MCS7840_DEV_MODE_SELECT24S bit in MODE R/Only
324 	 * register. But vendor driver uses these undocumented
325 	 * register & bit.
326 	 *
327 	 * Experiments show, that MODE register can have `0'
328 	 * (4 ports) bit on 2-port device, so use vendor driver's way.
329 	 *
330 	 * Also, see notes in header file for these constants.
331 	 */
332 	umcs7840_get_reg_sync(sc, MCS7840_DEV_REG_GPIO, &data);
333 	if (data & MCS7840_DEV_GPIO_4PORTS) {
334 		sc->sc_numports = 4;
335 		/* Store physical port numbers in sc_portno */
336 		sc->sc_ucom[0].sc_portno = 0;
337 		sc->sc_ucom[1].sc_portno = 1;
338 		sc->sc_ucom[2].sc_portno = 2;
339 		sc->sc_ucom[3].sc_portno = 3;
340 	} else {
341 		sc->sc_numports = 2;
342 		/* Store physical port numbers in sc_portno */
343 		sc->sc_ucom[0].sc_portno = 0;
344 		sc->sc_ucom[1].sc_portno = 2;	/* '1' is skipped */
345 	}
346 	device_printf(dev, "Chip mcs%04x, found %d active ports\n", uaa->info.idProduct, sc->sc_numports);
347 	if (!umcs7840_get_reg_sync(sc, MCS7840_DEV_REG_MODE, &data)) {
348 		device_printf(dev, "On-die confguration: RST: active %s, HRD: %s, PLL: %s, POR: %s, Ports: %s, EEPROM write %s, IrDA is %savailable\n",
349 		    (data & MCS7840_DEV_MODE_RESET) ? "low" : "high",
350 		    (data & MCS7840_DEV_MODE_SER_PRSNT) ? "yes" : "no",
351 		    (data & MCS7840_DEV_MODE_PLLBYPASS) ? "bypassed" : "avail",
352 		    (data & MCS7840_DEV_MODE_PORBYPASS) ? "bypassed" : "avail",
353 		    (data & MCS7840_DEV_MODE_SELECT24S) ? "2" : "4",
354 		    (data & MCS7840_DEV_MODE_EEPROMWR) ? "enabled" : "disabled",
355 		    (data & MCS7840_DEV_MODE_IRDA) ? "" : "not ");
356 	}
357 	/* Setup all transfers */
358 	for (subunit = 0; subunit < sc->sc_numports; ++subunit) {
359 		for (n = 0; n < UMCS7840_N_TRANSFERS; ++n) {
360 			/* Set endpoint address */
361 			umcs7840_config_tmp[n].endpoint = umcs7840_bulk_config_data[n].endpoint + 2 * sc->sc_ucom[subunit].sc_portno;
362 			umcs7840_config_tmp[n].callback = umcs7840_rw_callbacks[subunit][n];
363 		}
364 		error = usbd_transfer_setup(uaa->device,
365 		    &iface_index, sc->sc_ports[sc->sc_ucom[subunit].sc_portno].sc_xfer, umcs7840_config_tmp,
366 		    UMCS7840_N_TRANSFERS, sc, &sc->sc_mtx);
367 		if (error) {
368 			device_printf(dev, "allocating USB transfers failed for subunit %d of %d\n",
369 			    subunit + 1, sc->sc_numports);
370 			goto detach;
371 		}
372 	}
373 	error = usbd_transfer_setup(uaa->device,
374 	    &iface_index, &sc->sc_intr_xfer, umcs7840_intr_config_data,
375 	    1, sc, &sc->sc_mtx);
376 	if (error) {
377 		device_printf(dev, "allocating USB transfers failed for interrupt\n");
378 		goto detach;
379 	}
380 	/* clear stall at first run */
381 	mtx_lock(&sc->sc_mtx);
382 	for (subunit = 0; subunit < sc->sc_numports; ++subunit) {
383 		usbd_xfer_set_stall(sc->sc_ports[sc->sc_ucom[subunit].sc_portno].sc_xfer[UMCS7840_BULK_RD_EP]);
384 		usbd_xfer_set_stall(sc->sc_ports[sc->sc_ucom[subunit].sc_portno].sc_xfer[UMCS7840_BULK_WR_EP]);
385 	}
386 	mtx_unlock(&sc->sc_mtx);
387 
388 	error = ucom_attach(&sc->sc_super_ucom, sc->sc_ucom, sc->sc_numports, sc,
389 	    &umcs7840_callback, &sc->sc_mtx);
390 	if (error)
391 		goto detach;
392 
393 	ucom_set_pnpinfo_usb(&sc->sc_super_ucom, dev);
394 
395 	return (0);
396 
397 detach:
398 	umcs7840_detach(dev);
399 	return (ENXIO);
400 }
401 
402 static int
403 umcs7840_detach(device_t dev)
404 {
405 	struct umcs7840_softc *sc = device_get_softc(dev);
406 	int subunit;
407 
408 	ucom_detach(&sc->sc_super_ucom, sc->sc_ucom);
409 
410 	for (subunit = 0; subunit < sc->sc_numports; ++subunit)
411 		usbd_transfer_unsetup(sc->sc_ports[sc->sc_ucom[subunit].sc_portno].sc_xfer, UMCS7840_N_TRANSFERS);
412 	usbd_transfer_unsetup(&sc->sc_intr_xfer, 1);
413 
414 	device_claim_softc(dev);
415 
416 	umcs7840_free_softc(sc);
417 
418 	return (0);
419 }
420 
421 UCOM_UNLOAD_DRAIN(umcs7840);
422 
423 static void
424 umcs7840_free_softc(struct umcs7840_softc *sc)
425 {
426 	if (ucom_unref(&sc->sc_super_ucom)) {
427 		mtx_destroy(&sc->sc_mtx);
428 		device_free_softc(sc);
429 	}
430 }
431 
432 static void
433 umcs7840_free(struct ucom_softc *ucom)
434 {
435 	umcs7840_free_softc(ucom->sc_parent);
436 }
437 
438 static void
439 umcs7840_cfg_open(struct ucom_softc *ucom)
440 {
441 	struct umcs7840_softc *sc = ucom->sc_parent;
442 	uint16_t pn = ucom->sc_portno;
443 	uint8_t data;
444 
445 	/* If it very first open, finish global configuration */
446 	if (!sc->sc_driver_done) {
447 		/*
448 		 * USB enumeration is finished, pass internal memory to FIFOs
449 		 * If it is done in the end of "attach", kernel panics.
450 		 */
451 		if (umcs7840_get_reg_sync(sc, MCS7840_DEV_REG_CONTROL1, &data))
452 			return;
453 		data |= MCS7840_DEV_CONTROL1_DRIVER_DONE;
454 		if (umcs7840_set_reg_sync(sc, MCS7840_DEV_REG_CONTROL1, data))
455 			return;
456 		sc->sc_driver_done = 1;
457 	}
458 	/* Toggle reset bit on-off */
459 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, &data))
460 		return;
461 	data |= MCS7840_DEV_SPx_UART_RESET;
462 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, data))
463 		return;
464 	data &= ~MCS7840_DEV_SPx_UART_RESET;
465 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, data))
466 		return;
467 
468 	/* Set RS-232 mode */
469 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_SCRATCHPAD, MCS7840_UART_SCRATCHPAD_RS232))
470 		return;
471 
472 	/* Disable RX on time of initialization */
473 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_control, &data))
474 		return;
475 	data |= MCS7840_DEV_CONTROLx_RX_DISABLE;
476 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_control, data))
477 		return;
478 
479 	/* Disable all interrupts */
480 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_IER, 0))
481 		return;
482 
483 	/* Reset FIFO -- documented */
484 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_FCR, 0))
485 		return;
486 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_FCR,
487 	    MCS7840_UART_FCR_ENABLE | MCS7840_UART_FCR_FLUSHRHR |
488 	    MCS7840_UART_FCR_FLUSHTHR | MCS7840_UART_FCR_RTL_1_14))
489 		return;
490 
491 	/* Set 8 bit, no parity, 1 stop bit -- documented */
492 	sc->sc_ports[pn].sc_lcr = MCS7840_UART_LCR_DATALEN8 | MCS7840_UART_LCR_STOPB1;
493 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_LCR, sc->sc_ports[pn].sc_lcr))
494 		return;
495 
496 	/*
497 	 * Enable DTR/RTS on modem control, enable modem interrupts --
498 	 * documented
499 	 */
500 	sc->sc_ports[pn].sc_mcr = MCS7840_UART_MCR_DTR | MCS7840_UART_MCR_RTS | MCS7840_UART_MCR_IE;
501 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, sc->sc_ports[pn].sc_mcr))
502 		return;
503 
504 	/* Clearing Bulkin and Bulkout FIFO */
505 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, &data))
506 		return;
507 	data |= MCS7840_DEV_SPx_RESET_OUT_FIFO | MCS7840_DEV_SPx_RESET_IN_FIFO;
508 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, data))
509 		return;
510 	data &= ~(MCS7840_DEV_SPx_RESET_OUT_FIFO | MCS7840_DEV_SPx_RESET_IN_FIFO);
511 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_sp, data))
512 		return;
513 
514 	/* Set speed 9600 */
515 	if (umcs7840_set_baudrate(sc, pn, 9600))
516 		return;
517 
518 
519 	/* Finally enable all interrupts -- documented */
520 	/*
521 	 * Copied from vendor driver, I don't know why we should read LCR
522 	 * here
523 	 */
524 	if (umcs7840_get_UART_reg_sync(sc, pn, MCS7840_UART_REG_LCR, &sc->sc_ports[pn].sc_lcr))
525 		return;
526 	if (umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_IER,
527 	    MCS7840_UART_IER_RXSTAT | MCS7840_UART_IER_MODEM))
528 		return;
529 
530 	/* Enable RX */
531 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_control, &data))
532 		return;
533 	data &= ~MCS7840_DEV_CONTROLx_RX_DISABLE;
534 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_control, data))
535 		return;
536 
537 	DPRINTF("Port %d has been opened\n", pn);
538 }
539 
540 static void
541 umcs7840_cfg_close(struct ucom_softc *ucom)
542 {
543 	struct umcs7840_softc *sc = ucom->sc_parent;
544 	uint16_t pn = ucom->sc_portno;
545 	uint8_t data;
546 
547 	umcs7840_stop_read(ucom);
548 	umcs7840_stop_write(ucom);
549 
550 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, 0);
551 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_IER, 0);
552 
553 	/* Disable RX */
554 	if (umcs7840_get_reg_sync(sc, umcs7840_port_registers[pn].reg_control, &data))
555 		return;
556 	data |= MCS7840_DEV_CONTROLx_RX_DISABLE;
557 	if (umcs7840_set_reg_sync(sc, umcs7840_port_registers[pn].reg_control, data))
558 		return;
559 	DPRINTF("Port %d has been closed\n", pn);
560 }
561 
562 static void
563 umcs7840_cfg_set_dtr(struct ucom_softc *ucom, uint8_t onoff)
564 {
565 	struct umcs7840_softc *sc = ucom->sc_parent;
566 	uint8_t pn = ucom->sc_portno;
567 
568 	if (onoff)
569 		sc->sc_ports[pn].sc_mcr |= MCS7840_UART_MCR_DTR;
570 	else
571 		sc->sc_ports[pn].sc_mcr &= ~MCS7840_UART_MCR_DTR;
572 
573 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, sc->sc_ports[pn].sc_mcr);
574 	DPRINTF("Port %d DTR set to: %s\n", pn, onoff ? "on" : "off");
575 }
576 
577 static void
578 umcs7840_cfg_set_rts(struct ucom_softc *ucom, uint8_t onoff)
579 {
580 	struct umcs7840_softc *sc = ucom->sc_parent;
581 	uint8_t pn = ucom->sc_portno;
582 
583 	if (onoff)
584 		sc->sc_ports[pn].sc_mcr |= MCS7840_UART_MCR_RTS;
585 	else
586 		sc->sc_ports[pn].sc_mcr &= ~MCS7840_UART_MCR_RTS;
587 
588 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, sc->sc_ports[pn].sc_mcr);
589 	DPRINTF("Port %d RTS set to: %s\n", pn, onoff ? "on" : "off");
590 }
591 
592 static void
593 umcs7840_cfg_set_break(struct ucom_softc *ucom, uint8_t onoff)
594 {
595 	struct umcs7840_softc *sc = ucom->sc_parent;
596 	uint8_t pn = ucom->sc_portno;
597 
598 	if (onoff)
599 		sc->sc_ports[pn].sc_lcr |= MCS7840_UART_LCR_BREAK;
600 	else
601 		sc->sc_ports[pn].sc_lcr &= ~MCS7840_UART_LCR_BREAK;
602 
603 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_LCR, sc->sc_ports[pn].sc_lcr);
604 	DPRINTF("Port %d BREAK set to: %s\n", pn, onoff ? "on" : "off");
605 }
606 
607 
608 static void
609 umcs7840_cfg_param(struct ucom_softc *ucom, struct termios *t)
610 {
611 	struct umcs7840_softc *sc = ucom->sc_parent;
612 	uint8_t pn = ucom->sc_portno;
613 	uint8_t lcr = sc->sc_ports[pn].sc_lcr;
614 	uint8_t mcr = sc->sc_ports[pn].sc_mcr;
615 
616 	DPRINTF("Port %d config:\n", pn);
617 	if (t->c_cflag & CSTOPB) {
618 		DPRINTF("  2 stop bits\n");
619 		lcr |= MCS7840_UART_LCR_STOPB2;
620 	} else {
621 		lcr |= MCS7840_UART_LCR_STOPB1;
622 		DPRINTF("  1 stop bit\n");
623 	}
624 
625 	lcr &= ~MCS7840_UART_LCR_PARITYMASK;
626 	if (t->c_cflag & PARENB) {
627 		lcr |= MCS7840_UART_LCR_PARITYON;
628 		if (t->c_cflag & PARODD) {
629 			lcr = MCS7840_UART_LCR_PARITYODD;
630 			DPRINTF("  parity on - odd\n");
631 		} else {
632 			lcr = MCS7840_UART_LCR_PARITYEVEN;
633 			DPRINTF("  parity on - even\n");
634 		}
635 	} else {
636 		lcr &= ~MCS7840_UART_LCR_PARITYON;
637 		DPRINTF("  parity off\n");
638 	}
639 
640 	lcr &= ~MCS7840_UART_LCR_DATALENMASK;
641 	switch (t->c_cflag & CSIZE) {
642 	case CS5:
643 		lcr |= MCS7840_UART_LCR_DATALEN5;
644 		DPRINTF("  5 bit\n");
645 		break;
646 	case CS6:
647 		lcr |= MCS7840_UART_LCR_DATALEN6;
648 		DPRINTF("  6 bit\n");
649 		break;
650 	case CS7:
651 		lcr |= MCS7840_UART_LCR_DATALEN7;
652 		DPRINTF("  7 bit\n");
653 		break;
654 	case CS8:
655 		lcr |= MCS7840_UART_LCR_DATALEN8;
656 		DPRINTF("  8 bit\n");
657 		break;
658 	}
659 
660 	if (t->c_cflag & CRTSCTS) {
661 		mcr |= MCS7840_UART_MCR_CTSRTS;
662 		DPRINTF("  CTS/RTS\n");
663 	} else
664 		mcr &= ~MCS7840_UART_MCR_CTSRTS;
665 
666 	if (t->c_cflag & (CDTR_IFLOW | CDSR_OFLOW)) {
667 		mcr |= MCS7840_UART_MCR_DTRDSR;
668 		DPRINTF("  DTR/DSR\n");
669 	} else
670 		mcr &= ~MCS7840_UART_MCR_DTRDSR;
671 
672 	sc->sc_ports[pn].sc_lcr = lcr;
673 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_LCR, sc->sc_ports[pn].sc_lcr);
674 	DPRINTF("Port %d LCR=%02x\n", pn, sc->sc_ports[pn].sc_lcr);
675 
676 	sc->sc_ports[pn].sc_mcr = mcr;
677 	umcs7840_set_UART_reg_sync(sc, pn, MCS7840_UART_REG_MCR, sc->sc_ports[pn].sc_mcr);
678 	DPRINTF("Port %d MCR=%02x\n", pn, sc->sc_ports[pn].sc_mcr);
679 
680 	umcs7840_set_baudrate(sc, pn, t->c_ospeed);
681 }
682 
683 
684 static int
685 umcs7840_pre_param(struct ucom_softc *ucom, struct termios *t)
686 {
687 	uint8_t clk;
688 	uint16_t divisor;
689 
690 	if (umcs7840_calc_baudrate(t->c_ospeed, &divisor, &clk) || !divisor)
691 		return (EINVAL);
692 	return (0);
693 }
694 
695 static void
696 umcs7840_start_read(struct ucom_softc *ucom)
697 {
698 	struct umcs7840_softc *sc = ucom->sc_parent;
699 	uint8_t pn = ucom->sc_portno;
700 
701 	/* Start interrupt transfer */
702 	usbd_transfer_start(sc->sc_intr_xfer);
703 
704 	/* Start read transfer */
705 	usbd_transfer_start(sc->sc_ports[pn].sc_xfer[UMCS7840_BULK_RD_EP]);
706 }
707 
708 static void
709 umcs7840_stop_read(struct ucom_softc *ucom)
710 {
711 	struct umcs7840_softc *sc = ucom->sc_parent;
712 	uint8_t pn = ucom->sc_portno;
713 
714 	/* Stop read transfer */
715 	usbd_transfer_stop(sc->sc_ports[pn].sc_xfer[UMCS7840_BULK_RD_EP]);
716 }
717 
718 static void
719 umcs7840_start_write(struct ucom_softc *ucom)
720 {
721 	struct umcs7840_softc *sc = ucom->sc_parent;
722 	uint8_t pn = ucom->sc_portno;
723 
724 	/* Start interrupt transfer */
725 	usbd_transfer_start(sc->sc_intr_xfer);
726 
727 	/* Start write transfer */
728 	usbd_transfer_start(sc->sc_ports[pn].sc_xfer[UMCS7840_BULK_WR_EP]);
729 }
730 
731 static void
732 umcs7840_stop_write(struct ucom_softc *ucom)
733 {
734 	struct umcs7840_softc *sc = ucom->sc_parent;
735 	uint8_t pn = ucom->sc_portno;
736 
737 	/* Stop write transfer */
738 	usbd_transfer_stop(sc->sc_ports[pn].sc_xfer[UMCS7840_BULK_WR_EP]);
739 }
740 
741 static void
742 umcs7840_cfg_get_status(struct ucom_softc *ucom, uint8_t *lsr, uint8_t *msr)
743 {
744 	struct umcs7840_softc *sc = ucom->sc_parent;
745 	uint8_t pn = ucom->sc_portno;
746 	uint8_t	hw_msr = 0;	/* local modem status register */
747 
748 	/*
749 	 * Read status registers.  MSR bits need translation from ns16550 to
750 	 * SER_* values.  LSR bits are ns16550 in hardware and ucom.
751 	 */
752 	umcs7840_get_UART_reg_sync(sc, pn, MCS7840_UART_REG_LSR, lsr);
753 	umcs7840_get_UART_reg_sync(sc, pn, MCS7840_UART_REG_MSR, &hw_msr);
754 
755 	if (hw_msr & MCS7840_UART_MSR_NEGCTS)
756 		*msr |= SER_CTS;
757 
758 	if (hw_msr & MCS7840_UART_MSR_NEGDCD)
759 		*msr |= SER_DCD;
760 
761 	if (hw_msr & MCS7840_UART_MSR_NEGRI)
762 		*msr |= SER_RI;
763 
764 	if (hw_msr & MCS7840_UART_MSR_NEGDSR)
765 		*msr |= SER_DSR;
766 
767 	DPRINTF("Port %d status: LSR=%02x MSR=%02x\n", ucom->sc_portno, *lsr, *msr);
768 }
769 
770 static void
771 umcs7840_intr_callback(struct usb_xfer *xfer, usb_error_t error)
772 {
773 	struct umcs7840_softc *sc = usbd_xfer_softc(xfer);
774 	struct usb_page_cache *pc;
775 	uint8_t buf[13];
776 	int actlen;
777 	int subunit;
778 
779 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
780 
781 	switch (USB_GET_STATE(xfer)) {
782 	case USB_ST_TRANSFERRED:
783 		if (actlen == 5 || actlen == 13) {
784 			pc = usbd_xfer_get_frame(xfer, 0);
785 			usbd_copy_out(pc, 0, buf, actlen);
786 			/* Check status of all ports */
787 			for (subunit = 0; subunit < sc->sc_numports; ++subunit) {
788 				uint8_t pn = sc->sc_ucom[subunit].sc_portno;
789 
790 				if (buf[pn] & MCS7840_UART_ISR_NOPENDING)
791 					continue;
792 				DPRINTF("Port %d has pending interrupt: %02x (FIFO: %02x)\n", pn, buf[pn] & MCS7840_UART_ISR_INTMASK, buf[pn] & (~MCS7840_UART_ISR_INTMASK));
793 				switch (buf[pn] & MCS7840_UART_ISR_INTMASK) {
794 				case MCS7840_UART_ISR_RXERR:
795 				case MCS7840_UART_ISR_RXHASDATA:
796 				case MCS7840_UART_ISR_RXTIMEOUT:
797 				case MCS7840_UART_ISR_MSCHANGE:
798 					ucom_status_change(&sc->sc_ucom[subunit]);
799 					break;
800 				default:
801 					/* Do nothing */
802 					break;
803 				}
804 			}
805 		} else
806 			device_printf(sc->sc_dev, "Invalid interrupt data length %d", actlen);
807 		/* FALLTHROUGH */
808 	case USB_ST_SETUP:
809 tr_setup:
810 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
811 		usbd_transfer_submit(xfer);
812 		return;
813 
814 	default:			/* Error */
815 		if (error != USB_ERR_CANCELLED) {
816 			/* try to clear stall first */
817 			usbd_xfer_set_stall(xfer);
818 			goto tr_setup;
819 		}
820 		return;
821 	}
822 }
823 
824 static void
825 umcs7840_read_callback1(struct usb_xfer *xfer, usb_error_t error)
826 {
827 	umcs7840_read_callbackN(xfer, error, 0);
828 }
829 
830 static void
831 umcs7840_read_callback2(struct usb_xfer *xfer, usb_error_t error)
832 {
833 	umcs7840_read_callbackN(xfer, error, 1);
834 }
835 static void
836 umcs7840_read_callback3(struct usb_xfer *xfer, usb_error_t error)
837 {
838 	umcs7840_read_callbackN(xfer, error, 2);
839 }
840 
841 static void
842 umcs7840_read_callback4(struct usb_xfer *xfer, usb_error_t error)
843 {
844 	umcs7840_read_callbackN(xfer, error, 3);
845 }
846 
847 static void
848 umcs7840_read_callbackN(struct usb_xfer *xfer, usb_error_t error, uint8_t subunit)
849 {
850 	struct umcs7840_softc *sc = usbd_xfer_softc(xfer);
851 	struct ucom_softc *ucom = &sc->sc_ucom[subunit];
852 	struct usb_page_cache *pc;
853 	int actlen;
854 
855 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
856 
857 	DPRINTF("Port %d read, state = %d, data length = %d\n", ucom->sc_portno, USB_GET_STATE(xfer), actlen);
858 
859 	switch (USB_GET_STATE(xfer)) {
860 	case USB_ST_TRANSFERRED:
861 		pc = usbd_xfer_get_frame(xfer, 0);
862 		ucom_put_data(ucom, pc, 0, actlen);
863 		/* FALLTHROUGH */
864 	case USB_ST_SETUP:
865 tr_setup:
866 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
867 		usbd_transfer_submit(xfer);
868 		return;
869 
870 	default:			/* Error */
871 		if (error != USB_ERR_CANCELLED) {
872 			/* try to clear stall first */
873 			usbd_xfer_set_stall(xfer);
874 			goto tr_setup;
875 		}
876 		return;
877 	}
878 }
879 
880 static void
881 umcs7840_write_callback1(struct usb_xfer *xfer, usb_error_t error)
882 {
883 	umcs7840_write_callbackN(xfer, error, 0);
884 }
885 
886 static void
887 umcs7840_write_callback2(struct usb_xfer *xfer, usb_error_t error)
888 {
889 	umcs7840_write_callbackN(xfer, error, 1);
890 }
891 
892 static void
893 umcs7840_write_callback3(struct usb_xfer *xfer, usb_error_t error)
894 {
895 	umcs7840_write_callbackN(xfer, error, 2);
896 }
897 
898 static void
899 umcs7840_write_callback4(struct usb_xfer *xfer, usb_error_t error)
900 {
901 	umcs7840_write_callbackN(xfer, error, 3);
902 }
903 
904 static void
905 umcs7840_write_callbackN(struct usb_xfer *xfer, usb_error_t error, uint8_t subunit)
906 {
907 	struct umcs7840_softc *sc = usbd_xfer_softc(xfer);
908 	struct ucom_softc *ucom = &sc->sc_ucom[subunit];
909 	struct usb_page_cache *pc;
910 	uint32_t actlen;
911 
912 	DPRINTF("Port %d write, state = %d\n", ucom->sc_portno, USB_GET_STATE(xfer));
913 
914 	switch (USB_GET_STATE(xfer)) {
915 	case USB_ST_SETUP:
916 	case USB_ST_TRANSFERRED:
917 tr_setup:
918 		pc = usbd_xfer_get_frame(xfer, 0);
919 		if (ucom_get_data(ucom, pc, 0, usbd_xfer_max_len(xfer), &actlen)) {
920 			DPRINTF("Port %d write, has %d bytes\n", ucom->sc_portno, actlen);
921 			usbd_xfer_set_frame_len(xfer, 0, actlen);
922 			usbd_transfer_submit(xfer);
923 		}
924 		return;
925 
926 	default:			/* Error */
927 		if (error != USB_ERR_CANCELLED) {
928 			/* try to clear stall first */
929 			usbd_xfer_set_stall(xfer);
930 			goto tr_setup;
931 		}
932 		return;
933 	}
934 }
935 
936 static void
937 umcs7840_poll(struct ucom_softc *ucom)
938 {
939 	struct umcs7840_softc *sc = ucom->sc_parent;
940 
941 	DPRINTF("Port %d poll\n", ucom->sc_portno);
942 	usbd_transfer_poll(sc->sc_ports[ucom->sc_portno].sc_xfer, UMCS7840_N_TRANSFERS);
943 	usbd_transfer_poll(&sc->sc_intr_xfer, 1);
944 }
945 
946 static usb_error_t
947 umcs7840_get_reg_sync(struct umcs7840_softc *sc, uint8_t reg, uint8_t *data)
948 {
949 	struct usb_device_request req;
950 	usb_error_t err;
951 	uint16_t len;
952 
953 	req.bmRequestType = UT_READ_VENDOR_DEVICE;
954 	req.bRequest = MCS7840_RDREQ;
955 	USETW(req.wValue, 0);
956 	USETW(req.wIndex, reg);
957 	USETW(req.wLength, UMCS7840_READ_LENGTH);
958 
959 	err = usbd_do_request_proc(sc->sc_udev, &sc->sc_super_ucom.sc_tq, &req, (void *)data, 0, &len, UMCS7840_CTRL_TIMEOUT);
960 	if (err == USB_ERR_NORMAL_COMPLETION && len != 1) {
961 		device_printf(sc->sc_dev, "Reading register %d failed: invalid length %d\n", reg, len);
962 		return (USB_ERR_INVAL);
963 	} else if (err)
964 		device_printf(sc->sc_dev, "Reading register %d failed: %s\n", reg, usbd_errstr(err));
965 	return (err);
966 }
967 
968 static usb_error_t
969 umcs7840_set_reg_sync(struct umcs7840_softc *sc, uint8_t reg, uint8_t data)
970 {
971 	struct usb_device_request req;
972 	usb_error_t err;
973 
974 	req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
975 	req.bRequest = MCS7840_WRREQ;
976 	USETW(req.wValue, data);
977 	USETW(req.wIndex, reg);
978 	USETW(req.wLength, 0);
979 
980 	err = usbd_do_request_proc(sc->sc_udev, &sc->sc_super_ucom.sc_tq, &req, NULL, 0, NULL, UMCS7840_CTRL_TIMEOUT);
981 	if (err)
982 		device_printf(sc->sc_dev, "Writing register %d failed: %s\n", reg, usbd_errstr(err));
983 
984 	return (err);
985 }
986 
987 static usb_error_t
988 umcs7840_get_UART_reg_sync(struct umcs7840_softc *sc, uint8_t portno, uint8_t reg, uint8_t *data)
989 {
990 	struct usb_device_request req;
991 	uint16_t wVal;
992 	usb_error_t err;
993 	uint16_t len;
994 
995 	/* portno is port number */
996 	wVal = ((uint16_t)(portno + 1)) << 8;
997 
998 	req.bmRequestType = UT_READ_VENDOR_DEVICE;
999 	req.bRequest = MCS7840_RDREQ;
1000 	USETW(req.wValue, wVal);
1001 	USETW(req.wIndex, reg);
1002 	USETW(req.wLength, UMCS7840_READ_LENGTH);
1003 
1004 	err = usbd_do_request_proc(sc->sc_udev, &sc->sc_super_ucom.sc_tq, &req, (void *)data, 0, &len, UMCS7840_CTRL_TIMEOUT);
1005 	if (err == USB_ERR_NORMAL_COMPLETION && len != 1) {
1006 		device_printf(sc->sc_dev, "Reading UART%d register %d failed: invalid length %d\n", portno, reg, len);
1007 		return (USB_ERR_INVAL);
1008 	} else if (err)
1009 		device_printf(sc->sc_dev, "Reading UART%d register %d failed: %s\n", portno, reg, usbd_errstr(err));
1010 	return (err);
1011 }
1012 
1013 static usb_error_t
1014 umcs7840_set_UART_reg_sync(struct umcs7840_softc *sc, uint8_t portno, uint8_t reg, uint8_t data)
1015 {
1016 	struct usb_device_request req;
1017 	usb_error_t err;
1018 	uint16_t wVal;
1019 
1020 	/* portno is port number */
1021 	wVal = ((uint16_t)(portno + 1)) << 8 | data;
1022 
1023 	req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
1024 	req.bRequest = MCS7840_WRREQ;
1025 	USETW(req.wValue, wVal);
1026 	USETW(req.wIndex, reg);
1027 	USETW(req.wLength, 0);
1028 
1029 	err = usbd_do_request_proc(sc->sc_udev, &sc->sc_super_ucom.sc_tq, &req, NULL, 0, NULL, UMCS7840_CTRL_TIMEOUT);
1030 	if (err)
1031 		device_printf(sc->sc_dev, "Writing UART%d register %d failed: %s\n", portno, reg, usbd_errstr(err));
1032 	return (err);
1033 }
1034 
1035 static usb_error_t
1036 umcs7840_set_baudrate(struct umcs7840_softc *sc, uint8_t portno, uint32_t rate)
1037 {
1038 	usb_error_t err;
1039 	uint16_t divisor;
1040 	uint8_t clk;
1041 	uint8_t data;
1042 
1043 	if (umcs7840_calc_baudrate(rate, &divisor, &clk)) {
1044 		DPRINTF("Port %d bad speed: %d\n", portno, rate);
1045 		return (-1);
1046 	}
1047 	if (divisor == 0 || (clk & MCS7840_DEV_SPx_CLOCK_MASK) != clk) {
1048 		DPRINTF("Port %d bad speed calculation: %d\n", portno, rate);
1049 		return (-1);
1050 	}
1051 	DPRINTF("Port %d set speed: %d (%02x / %d)\n", portno, rate, clk, divisor);
1052 
1053 	/* Set clock source for standard BAUD frequences */
1054 	err = umcs7840_get_reg_sync(sc, umcs7840_port_registers[portno].reg_sp, &data);
1055 	if (err)
1056 		return (err);
1057 	data &= MCS7840_DEV_SPx_CLOCK_MASK;
1058 	data |= clk;
1059 	err = umcs7840_set_reg_sync(sc, umcs7840_port_registers[portno].reg_sp, data);
1060 	if (err)
1061 		return (err);
1062 
1063 	/* Set divider */
1064 	sc->sc_ports[portno].sc_lcr |= MCS7840_UART_LCR_DIVISORS;
1065 	err = umcs7840_set_UART_reg_sync(sc, portno, MCS7840_UART_REG_LCR, sc->sc_ports[portno].sc_lcr);
1066 	if (err)
1067 		return (err);
1068 
1069 	err = umcs7840_set_UART_reg_sync(sc, portno, MCS7840_UART_REG_DLL, (uint8_t)(divisor & 0xff));
1070 	if (err)
1071 		return (err);
1072 	err = umcs7840_set_UART_reg_sync(sc, portno, MCS7840_UART_REG_DLM, (uint8_t)((divisor >> 8) & 0xff));
1073 	if (err)
1074 		return (err);
1075 
1076 	/* Turn off access to DLL/DLM registers of UART */
1077 	sc->sc_ports[portno].sc_lcr &= ~MCS7840_UART_LCR_DIVISORS;
1078 	err = umcs7840_set_UART_reg_sync(sc, portno, MCS7840_UART_REG_LCR, sc->sc_ports[portno].sc_lcr);
1079 	if (err)
1080 		return (err);
1081 	return (0);
1082 }
1083 
1084 /* Maximum speeds for standard frequences, when PLL is not used */
1085 static const uint32_t umcs7840_baudrate_divisors[] = {0, 115200, 230400, 403200, 460800, 806400, 921600, 1572864, 3145728,};
1086 static const uint8_t umcs7840_baudrate_divisors_len = nitems(umcs7840_baudrate_divisors);
1087 
1088 static usb_error_t
1089 umcs7840_calc_baudrate(uint32_t rate, uint16_t *divisor, uint8_t *clk)
1090 {
1091 	uint8_t i = 0;
1092 
1093 	if (rate > umcs7840_baudrate_divisors[umcs7840_baudrate_divisors_len - 1])
1094 		return (-1);
1095 
1096 	for (i = 0; i < umcs7840_baudrate_divisors_len - 1 &&
1097 	    !(rate > umcs7840_baudrate_divisors[i] && rate <= umcs7840_baudrate_divisors[i + 1]); ++i);
1098 	if (rate == 0)
1099 		*divisor = 1;	/* XXX */
1100 	else
1101 		*divisor = umcs7840_baudrate_divisors[i + 1] / rate;
1102 	/* 0x00 .. 0x70 */
1103 	*clk = i << MCS7840_DEV_SPx_CLOCK_SHIFT;
1104 	return (0);
1105 }
1106