1 /*****************************************************************************/
4 * baycom_ser_hdx.c -- baycom ser12 halfduplex radio modem driver.
6 * Copyright (C) 1996-2000 Thomas Sailer (sailer@ife.ee.ethz.ch)
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 * Please note that the GPL allows you to use the driver, NOT the radio.
23 * In order to use the radio, you need a license from the communications
24 * authority of your country.
29 * ser12: This is a very simple 1200 baud AFSK modem. The modem consists only
30 * of a modulator/demodulator chip, usually a TI TCM3105. The computer
31 * is responsible for regenerating the receiver bit clock, as well as
32 * for handling the HDLC protocol. The modem connects to a serial port,
33 * hence the name. Since the serial port is not used as an async serial
34 * port, the kernel driver for serial ports cannot be used, and this
35 * driver only supports standard serial hardware (8250, 16450, 16550A)
38 * Command line options (insmod command line)
40 * mode ser12 hardware DCD
42 * ser12@ hardware/software DCD, i.e. no explicit DCD signal but hardware
43 * mutes audio input to the modem
44 * ser12+ hardware DCD, inverted signal at DCD pin
45 * iobase base address of the port; common values are 0x3f8, 0x2f8, 0x3e8, 0x2e8
46 * irq interrupt line of the port; common values are 4,3
50 * 0.1 26.06.1996 Adapted from baycom.c and made network driver interface
51 * 18.10.1996 Changed to new user space access routines (copy_{to,from}_user)
52 * 0.3 26.04.1997 init code/data tagged
53 * 0.4 08.07.1997 alternative ser12 decoding algorithm (uses delta CTS ints)
54 * 0.5 11.11.1997 ser12/par96 split into separate files
55 * 0.6 14.04.1998 cleanups
56 * 0.7 03.08.1999 adapt to Linus' new __setup/__initcall
57 * 0.8 10.08.1999 use module_init/module_exit
58 * 0.9 12.02.2000 adapted to softnet driver interface
59 * 0.10 03.07.2000 fix interface name handling
62 /*****************************************************************************/
64 #include <linux/capability.h>
65 #include <linux/module.h>
66 #include <linux/ioport.h>
67 #include <linux/string.h>
68 #include <linux/init.h>
69 #include <linux/interrupt.h>
70 #include <asm/uaccess.h>
72 #include <linux/hdlcdrv.h>
73 #include <linux/baycom.h>
74 #include <linux/jiffies.h>
76 /* --------------------------------------------------------------------- */
80 /* --------------------------------------------------------------------- */
82 static const char bc_drvname
[] = "baycom_ser_hdx";
83 static const char bc_drvinfo
[] = KERN_INFO
"baycom_ser_hdx: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
84 "baycom_ser_hdx: version 0.10\n";
86 /* --------------------------------------------------------------------- */
90 static struct net_device
*baycom_device
[NR_PORTS
];
92 /* --------------------------------------------------------------------- */
94 #define RBR(iobase) (iobase+0)
95 #define THR(iobase) (iobase+0)
96 #define IER(iobase) (iobase+1)
97 #define IIR(iobase) (iobase+2)
98 #define FCR(iobase) (iobase+2)
99 #define LCR(iobase) (iobase+3)
100 #define MCR(iobase) (iobase+4)
101 #define LSR(iobase) (iobase+5)
102 #define MSR(iobase) (iobase+6)
103 #define SCR(iobase) (iobase+7)
104 #define DLL(iobase) (iobase+0)
105 #define DLM(iobase) (iobase+1)
107 #define SER12_EXTENT 8
109 /* ---------------------------------------------------------------------- */
111 * Information that need to be kept for each board.
114 struct baycom_state
{
115 struct hdlcdrv_state hdrv
;
123 struct modem_state_ser12
{
124 unsigned char tx_bit
;
125 int dcd_sum0
, dcd_sum1
, dcd_sum2
;
126 unsigned char last_sample
;
127 unsigned char last_rxbit
;
128 unsigned int dcd_shreg
;
129 unsigned int dcd_time
;
130 unsigned int bit_pll
;
131 unsigned char interm_sample
;
137 unsigned long last_jiffies
;
139 unsigned last_intcnt
;
143 #endif /* BAYCOM_DEBUG */
146 /* --------------------------------------------------------------------- */
148 static inline void baycom_int_freq(struct baycom_state
*bc
)
151 unsigned long cur_jiffies
= jiffies
;
153 * measure the interrupt frequency
155 bc
->debug_vals
.cur_intcnt
++;
156 if (time_after_eq(cur_jiffies
, bc
->debug_vals
.last_jiffies
+ HZ
)) {
157 bc
->debug_vals
.last_jiffies
= cur_jiffies
;
158 bc
->debug_vals
.last_intcnt
= bc
->debug_vals
.cur_intcnt
;
159 bc
->debug_vals
.cur_intcnt
= 0;
160 bc
->debug_vals
.last_pllcorr
= bc
->debug_vals
.cur_pllcorr
;
161 bc
->debug_vals
.cur_pllcorr
= 0;
163 #endif /* BAYCOM_DEBUG */
166 /* --------------------------------------------------------------------- */
168 * ===================== SER12 specific routines =========================
171 static inline void ser12_set_divisor(struct net_device
*dev
,
172 unsigned char divisor
)
174 outb(0x81, LCR(dev
->base_addr
)); /* DLAB = 1 */
175 outb(divisor
, DLL(dev
->base_addr
));
176 outb(0, DLM(dev
->base_addr
));
177 outb(0x01, LCR(dev
->base_addr
)); /* word length = 6 */
179 * make sure the next interrupt is generated;
180 * 0 must be used to power the modem; the modem draws its
181 * power from the TxD line
183 outb(0x00, THR(dev
->base_addr
));
185 * it is important not to set the divider while transmitting;
186 * this reportedly makes some UARTs generating interrupts
187 * in the hundredthousands per second region
188 * Reported by: Ignacio.Arenaza@studi.epfl.ch (Ignacio Arenaza Nuno)
192 /* --------------------------------------------------------------------- */
195 * must call the TX arbitrator every 10ms
197 #define SER12_ARB_DIVIDER(bc) (bc->opt_dcd ? 24 : 36)
199 #define SER12_DCD_INTERVAL(bc) (bc->opt_dcd ? 12 : 240)
201 static inline void ser12_tx(struct net_device
*dev
, struct baycom_state
*bc
)
203 /* one interrupt per channel bit */
204 ser12_set_divisor(dev
, 12);
206 * first output the last bit (!) then call HDLC transmitter,
207 * since this may take quite long
209 outb(0x0e | (!!bc
->modem
.ser12
.tx_bit
), MCR(dev
->base_addr
));
210 if (bc
->modem
.shreg
<= 1)
211 bc
->modem
.shreg
= 0x10000 | hdlcdrv_getbits(&bc
->hdrv
);
212 bc
->modem
.ser12
.tx_bit
= !(bc
->modem
.ser12
.tx_bit
^
213 (bc
->modem
.shreg
& 1));
214 bc
->modem
.shreg
>>= 1;
217 /* --------------------------------------------------------------------- */
219 static inline void ser12_rx(struct net_device
*dev
, struct baycom_state
*bc
)
225 cur_s
= inb(MSR(dev
->base_addr
)) & 0x10; /* the CTS line */
226 hdlcdrv_channelbit(&bc
->hdrv
, cur_s
);
227 bc
->modem
.ser12
.dcd_shreg
= (bc
->modem
.ser12
.dcd_shreg
<< 1) |
228 (cur_s
!= bc
->modem
.ser12
.last_sample
);
229 bc
->modem
.ser12
.last_sample
= cur_s
;
230 if(bc
->modem
.ser12
.dcd_shreg
& 1) {
232 unsigned int dcdspos
, dcdsneg
;
234 dcdspos
= dcdsneg
= 0;
235 dcdspos
+= ((bc
->modem
.ser12
.dcd_shreg
>> 1) & 1);
236 if (!(bc
->modem
.ser12
.dcd_shreg
& 0x7ffffffe))
238 dcdsneg
+= ((bc
->modem
.ser12
.dcd_shreg
>> 2) & 1);
239 dcdsneg
+= ((bc
->modem
.ser12
.dcd_shreg
>> 3) & 1);
240 dcdsneg
+= ((bc
->modem
.ser12
.dcd_shreg
>> 4) & 1);
242 bc
->modem
.ser12
.dcd_sum0
+= 16*dcdspos
- dcdsneg
;
244 bc
->modem
.ser12
.dcd_sum0
--;
246 if(!bc
->modem
.ser12
.dcd_time
) {
247 hdlcdrv_setdcd(&bc
->hdrv
, (bc
->modem
.ser12
.dcd_sum0
+
248 bc
->modem
.ser12
.dcd_sum1
+
249 bc
->modem
.ser12
.dcd_sum2
) < 0);
250 bc
->modem
.ser12
.dcd_sum2
= bc
->modem
.ser12
.dcd_sum1
;
251 bc
->modem
.ser12
.dcd_sum1
= bc
->modem
.ser12
.dcd_sum0
;
252 /* offset to ensure DCD off on silent input */
253 bc
->modem
.ser12
.dcd_sum0
= 2;
254 bc
->modem
.ser12
.dcd_time
= SER12_DCD_INTERVAL(bc
);
256 bc
->modem
.ser12
.dcd_time
--;
259 * PLL code for the improved software DCD algorithm
261 if (bc
->modem
.ser12
.interm_sample
) {
263 * intermediate sample; set timing correction to normal
265 ser12_set_divisor(dev
, 4);
268 * do PLL correction and call HDLC receiver
270 switch (bc
->modem
.ser12
.dcd_shreg
& 7) {
271 case 1: /* transition too late */
272 ser12_set_divisor(dev
, 5);
274 bc
->debug_vals
.cur_pllcorr
++;
275 #endif /* BAYCOM_DEBUG */
277 case 4: /* transition too early */
278 ser12_set_divisor(dev
, 3);
280 bc
->debug_vals
.cur_pllcorr
--;
281 #endif /* BAYCOM_DEBUG */
284 ser12_set_divisor(dev
, 4);
287 bc
->modem
.shreg
>>= 1;
288 if (bc
->modem
.ser12
.last_sample
==
289 bc
->modem
.ser12
.last_rxbit
)
290 bc
->modem
.shreg
|= 0x10000;
291 bc
->modem
.ser12
.last_rxbit
=
292 bc
->modem
.ser12
.last_sample
;
294 if (++bc
->modem
.ser12
.interm_sample
>= 3)
295 bc
->modem
.ser12
.interm_sample
= 0;
299 if (bc
->modem
.ser12
.dcd_shreg
& 1) {
300 unsigned int dcdspos
, dcdsneg
;
302 dcdspos
= dcdsneg
= 0;
303 dcdspos
+= ((bc
->modem
.ser12
.dcd_shreg
>> 1) & 1);
304 dcdspos
+= (!(bc
->modem
.ser12
.dcd_shreg
& 0x7ffffffe))
306 dcdsneg
+= ((bc
->modem
.ser12
.dcd_shreg
>> 2) & 1);
307 dcdsneg
+= ((bc
->modem
.ser12
.dcd_shreg
>> 3) & 1);
308 dcdsneg
+= ((bc
->modem
.ser12
.dcd_shreg
>> 4) & 1);
310 bc
->modem
.ser12
.dcd_sum0
+= 16*dcdspos
- dcdsneg
;
314 * PLL algorithm for the hardware squelch DCD algorithm
316 if (bc
->modem
.ser12
.interm_sample
) {
318 * intermediate sample; set timing correction to normal
320 ser12_set_divisor(dev
, 6);
323 * do PLL correction and call HDLC receiver
325 switch (bc
->modem
.ser12
.dcd_shreg
& 3) {
326 case 1: /* transition too late */
327 ser12_set_divisor(dev
, 7);
329 bc
->debug_vals
.cur_pllcorr
++;
330 #endif /* BAYCOM_DEBUG */
332 case 2: /* transition too early */
333 ser12_set_divisor(dev
, 5);
335 bc
->debug_vals
.cur_pllcorr
--;
336 #endif /* BAYCOM_DEBUG */
339 ser12_set_divisor(dev
, 6);
342 bc
->modem
.shreg
>>= 1;
343 if (bc
->modem
.ser12
.last_sample
==
344 bc
->modem
.ser12
.last_rxbit
)
345 bc
->modem
.shreg
|= 0x10000;
346 bc
->modem
.ser12
.last_rxbit
=
347 bc
->modem
.ser12
.last_sample
;
349 bc
->modem
.ser12
.interm_sample
= !bc
->modem
.ser12
.interm_sample
;
353 bc
->modem
.ser12
.dcd_sum0
-= (bc
->modem
.ser12
.dcd_shreg
& 1);
355 outb(0x0d, MCR(dev
->base_addr
)); /* transmitter off */
356 if (bc
->modem
.shreg
& 1) {
357 hdlcdrv_putbits(&bc
->hdrv
, bc
->modem
.shreg
>> 1);
358 bc
->modem
.shreg
= 0x10000;
360 if(!bc
->modem
.ser12
.dcd_time
) {
362 hdlcdrv_setdcd(&bc
->hdrv
, !((inb(MSR(dev
->base_addr
)) ^ bc
->opt_dcd
) & 0x80));
364 hdlcdrv_setdcd(&bc
->hdrv
, (bc
->modem
.ser12
.dcd_sum0
+
365 bc
->modem
.ser12
.dcd_sum1
+
366 bc
->modem
.ser12
.dcd_sum2
) < 0);
367 bc
->modem
.ser12
.dcd_sum2
= bc
->modem
.ser12
.dcd_sum1
;
368 bc
->modem
.ser12
.dcd_sum1
= bc
->modem
.ser12
.dcd_sum0
;
369 /* offset to ensure DCD off on silent input */
370 bc
->modem
.ser12
.dcd_sum0
= 2;
371 bc
->modem
.ser12
.dcd_time
= SER12_DCD_INTERVAL(bc
);
373 bc
->modem
.ser12
.dcd_time
--;
376 /* --------------------------------------------------------------------- */
378 static irqreturn_t
ser12_interrupt(int irq
, void *dev_id
)
380 struct net_device
*dev
= (struct net_device
*)dev_id
;
381 struct baycom_state
*bc
= netdev_priv(dev
);
384 if (!dev
|| !bc
|| bc
->hdrv
.magic
!= HDLCDRV_MAGIC
)
387 if ((iir
= inb(IIR(dev
->base_addr
))) & 1)
393 inb(LSR(dev
->base_addr
));
397 inb(RBR(dev
->base_addr
));
402 * check if transmitter active
404 if (hdlcdrv_ptt(&bc
->hdrv
))
408 bc
->modem
.arb_divider
--;
410 outb(0x00, THR(dev
->base_addr
));
414 inb(MSR(dev
->base_addr
));
417 iir
= inb(IIR(dev
->base_addr
));
418 } while (!(iir
& 1));
419 if (bc
->modem
.arb_divider
<= 0) {
420 bc
->modem
.arb_divider
= SER12_ARB_DIVIDER(bc
);
422 hdlcdrv_arbitrate(dev
, &bc
->hdrv
);
425 hdlcdrv_transmitter(dev
, &bc
->hdrv
);
426 hdlcdrv_receiver(dev
, &bc
->hdrv
);
431 /* --------------------------------------------------------------------- */
433 enum uart
{ c_uart_unknown
, c_uart_8250
,
434 c_uart_16450
, c_uart_16550
, c_uart_16550A
};
435 static const char *uart_str
[] = {
436 "unknown", "8250", "16450", "16550", "16550A"
439 static enum uart
ser12_check_uart(unsigned int iobase
)
441 unsigned char b1
,b2
,b3
;
443 enum uart uart_tab
[] =
444 { c_uart_16450
, c_uart_unknown
, c_uart_16550
, c_uart_16550A
};
446 b1
= inb(MCR(iobase
));
447 outb(b1
| 0x10, MCR(iobase
)); /* loopback mode */
448 b2
= inb(MSR(iobase
));
449 outb(0x1a, MCR(iobase
));
450 b3
= inb(MSR(iobase
)) & 0xf0;
451 outb(b1
, MCR(iobase
)); /* restore old values */
452 outb(b2
, MSR(iobase
));
454 return c_uart_unknown
;
457 outb(0x01, FCR(iobase
)); /* enable FIFOs */
458 u
= uart_tab
[(inb(IIR(iobase
)) >> 6) & 3];
459 if (u
== c_uart_16450
) {
460 outb(0x5a, SCR(iobase
));
461 b1
= inb(SCR(iobase
));
462 outb(0xa5, SCR(iobase
));
463 b2
= inb(SCR(iobase
));
464 if ((b1
!= 0x5a) || (b2
!= 0xa5))
470 /* --------------------------------------------------------------------- */
472 static int ser12_open(struct net_device
*dev
)
474 struct baycom_state
*bc
= netdev_priv(dev
);
479 if (!dev
->base_addr
|| dev
->base_addr
> 0x1000-SER12_EXTENT
||
480 dev
->irq
< 2 || dev
->irq
> 15)
482 if (!request_region(dev
->base_addr
, SER12_EXTENT
, "baycom_ser12"))
484 memset(&bc
->modem
, 0, sizeof(bc
->modem
));
485 bc
->hdrv
.par
.bitrate
= 1200;
486 if ((u
= ser12_check_uart(dev
->base_addr
)) == c_uart_unknown
) {
487 release_region(dev
->base_addr
, SER12_EXTENT
);
490 outb(0, FCR(dev
->base_addr
)); /* disable FIFOs */
491 outb(0x0d, MCR(dev
->base_addr
));
492 outb(0, IER(dev
->base_addr
));
493 if (request_irq(dev
->irq
, ser12_interrupt
, IRQF_SHARED
,
494 "baycom_ser12", dev
)) {
495 release_region(dev
->base_addr
, SER12_EXTENT
);
499 * enable transmitter empty interrupt
501 outb(2, IER(dev
->base_addr
));
503 * set the SIO to 6 Bits/character and 19200 or 28800 baud, so that
504 * we get exactly (hopefully) 2 or 3 interrupts per radio symbol,
505 * depending on the usage of the software DCD routine
507 ser12_set_divisor(dev
, bc
->opt_dcd
? 6 : 4);
508 printk(KERN_INFO
"%s: ser12 at iobase 0x%lx irq %u uart %s\n",
509 bc_drvname
, dev
->base_addr
, dev
->irq
, uart_str
[u
]);
513 /* --------------------------------------------------------------------- */
515 static int ser12_close(struct net_device
*dev
)
517 struct baycom_state
*bc
= netdev_priv(dev
);
524 outb(0, IER(dev
->base_addr
));
525 outb(1, MCR(dev
->base_addr
));
526 free_irq(dev
->irq
, dev
);
527 release_region(dev
->base_addr
, SER12_EXTENT
);
528 printk(KERN_INFO
"%s: close ser12 at iobase 0x%lx irq %u\n",
529 bc_drvname
, dev
->base_addr
, dev
->irq
);
533 /* --------------------------------------------------------------------- */
535 * ===================== hdlcdrv driver interface =========================
538 /* --------------------------------------------------------------------- */
540 static int baycom_ioctl(struct net_device
*dev
, struct ifreq
*ifr
,
541 struct hdlcdrv_ioctl
*hi
, int cmd
);
543 /* --------------------------------------------------------------------- */
545 static struct hdlcdrv_ops ser12_ops
= {
546 .drvname
= bc_drvname
,
547 .drvinfo
= bc_drvinfo
,
549 .close
= ser12_close
,
550 .ioctl
= baycom_ioctl
,
553 /* --------------------------------------------------------------------- */
555 static int baycom_setmode(struct baycom_state
*bc
, const char *modestr
)
557 if (strchr(modestr
, '*'))
559 else if (strchr(modestr
, '+'))
561 else if (strchr(modestr
, '@'))
568 /* --------------------------------------------------------------------- */
570 static int baycom_ioctl(struct net_device
*dev
, struct ifreq
*ifr
,
571 struct hdlcdrv_ioctl
*hi
, int cmd
)
573 struct baycom_state
*bc
;
574 struct baycom_ioctl bi
;
579 bc
= netdev_priv(dev
);
580 BUG_ON(bc
->hdrv
.magic
!= HDLCDRV_MAGIC
);
582 if (cmd
!= SIOCDEVPRIVATE
)
588 case HDLCDRVCTL_GETMODE
:
589 strcpy(hi
->data
.modename
, "ser12");
590 if (bc
->opt_dcd
<= 0)
591 strcat(hi
->data
.modename
, (!bc
->opt_dcd
) ? "*" : (bc
->opt_dcd
== -2) ? "@" : "+");
592 if (copy_to_user(ifr
->ifr_data
, hi
, sizeof(struct hdlcdrv_ioctl
)))
596 case HDLCDRVCTL_SETMODE
:
597 if (netif_running(dev
) || !capable(CAP_NET_ADMIN
))
599 hi
->data
.modename
[sizeof(hi
->data
.modename
)-1] = '\0';
600 return baycom_setmode(bc
, hi
->data
.modename
);
602 case HDLCDRVCTL_MODELIST
:
603 strcpy(hi
->data
.modename
, "ser12");
604 if (copy_to_user(ifr
->ifr_data
, hi
, sizeof(struct hdlcdrv_ioctl
)))
608 case HDLCDRVCTL_MODEMPARMASK
:
609 return HDLCDRV_PARMASK_IOBASE
| HDLCDRV_PARMASK_IRQ
;
613 if (copy_from_user(&bi
, ifr
->ifr_data
, sizeof(bi
)))
620 case BAYCOMCTL_GETDEBUG
:
621 bi
.data
.dbg
.debug1
= bc
->hdrv
.ptt_keyed
;
622 bi
.data
.dbg
.debug2
= bc
->debug_vals
.last_intcnt
;
623 bi
.data
.dbg
.debug3
= bc
->debug_vals
.last_pllcorr
;
625 #endif /* BAYCOM_DEBUG */
628 if (copy_to_user(ifr
->ifr_data
, &bi
, sizeof(bi
)))
634 /* --------------------------------------------------------------------- */
637 * command line settable parameters
639 static char *mode
[NR_PORTS
] = { "ser12*", };
640 static int iobase
[NR_PORTS
] = { 0x3f8, };
641 static int irq
[NR_PORTS
] = { 4, };
643 module_param_array(mode
, charp
, NULL
, 0);
644 MODULE_PARM_DESC(mode
, "baycom operating mode; * for software DCD");
645 module_param_array(iobase
, int, NULL
, 0);
646 MODULE_PARM_DESC(iobase
, "baycom io base address");
647 module_param_array(irq
, int, NULL
, 0);
648 MODULE_PARM_DESC(irq
, "baycom irq number");
650 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
651 MODULE_DESCRIPTION("Baycom ser12 half duplex amateur radio modem driver");
652 MODULE_LICENSE("GPL");
654 /* --------------------------------------------------------------------- */
656 static int __init
init_baycomserhdx(void)
663 * register net devices
665 for (i
= 0; i
< NR_PORTS
; i
++) {
666 struct net_device
*dev
;
667 struct baycom_state
*bc
;
668 char ifname
[IFNAMSIZ
];
670 sprintf(ifname
, "bcsh%d", i
);
675 iobase
[i
] = irq
[i
] = 0;
677 dev
= hdlcdrv_register(&ser12_ops
,
678 sizeof(struct baycom_state
),
679 ifname
, iobase
[i
], irq
[i
], 0);
683 bc
= netdev_priv(dev
);
684 if (set_hw
&& baycom_setmode(bc
, mode
[i
]))
687 baycom_device
[i
] = dev
;
695 static void __exit
cleanup_baycomserhdx(void)
699 for(i
= 0; i
< NR_PORTS
; i
++) {
700 struct net_device
*dev
= baycom_device
[i
];
703 hdlcdrv_unregister(dev
);
707 module_init(init_baycomserhdx
);
708 module_exit(cleanup_baycomserhdx
);
710 /* --------------------------------------------------------------------- */
715 * format: baycom_ser_hdx=io,irq,mode
716 * mode: ser12 hardware DCD
717 * ser12* software DCD
718 * ser12@ hardware/software DCD, i.e. no explicit DCD signal but hardware
719 * mutes audio input to the modem
720 * ser12+ hardware DCD, inverted signal at DCD pin
723 static int __init
baycom_ser_hdx_setup(char *str
)
725 static unsigned nr_dev
;
728 if (nr_dev
>= NR_PORTS
)
730 str
= get_options(str
, 3, ints
);
734 iobase
[nr_dev
] = ints
[1];
735 irq
[nr_dev
] = ints
[2];
740 __setup("baycom_ser_hdx=", baycom_ser_hdx_setup
);
743 /* --------------------------------------------------------------------- */