678 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*****************************************************************************/3 4/*5 * baycom_ser_fdx.c -- baycom ser12 fullduplex radio modem driver.6 *7 * Copyright (C) 1996-2000 Thomas Sailer (sailer@ife.ee.ethz.ch)8 *9 * Please note that the GPL allows you to use the driver, NOT the radio.10 * In order to use the radio, you need a license from the communications11 * authority of your country.12 *13 * Supported modems14 *15 * ser12: This is a very simple 1200 baud AFSK modem. The modem consists only16 * of a modulator/demodulator chip, usually a TI TCM3105. The computer17 * is responsible for regenerating the receiver bit clock, as well as18 * for handling the HDLC protocol. The modem connects to a serial port,19 * hence the name. Since the serial port is not used as an async serial20 * port, the kernel driver for serial ports cannot be used, and this21 * driver only supports standard serial hardware (8250, 16450, 16550A)22 *23 * This modem usually draws its supply current out of the otherwise unused24 * TXD pin of the serial port. Thus a contiguous stream of 0x00-bytes25 * is transmitted to achieve a positive supply voltage.26 *27 * hsk: This is a 4800 baud FSK modem, designed for TNC use. It works fine28 * in 'baycom-mode' :-) In contrast to the TCM3105 modem, power is29 * externally supplied. So there's no need to provide the 0x00-byte-stream30 * when receiving or idle, which drastically reduces interrupt load.31 *32 * Command line options (insmod command line)33 *34 * mode ser# hardware DCD35 * ser#* software DCD36 * ser#+ hardware DCD, inverted signal at DCD pin37 * '#' denotes the baud rate / 100, eg. ser12* is '1200 baud, soft DCD'38 * iobase base address of the port; common values are 0x3f8, 0x2f8, 0x3e8, 0x2e839 * baud baud rate (between 300 and 4800)40 * irq interrupt line of the port; common values are 4,341 *42 * History:43 * 0.1 26.06.1996 Adapted from baycom.c and made network driver interface44 * 18.10.1996 Changed to new user space access routines (copy_{to,from}_user)45 * 0.3 26.04.1997 init code/data tagged46 * 0.4 08.07.1997 alternative ser12 decoding algorithm (uses delta CTS ints)47 * 0.5 11.11.1997 ser12/par96 split into separate files48 * 0.6 24.01.1998 Thorsten Kranzkowski, dl8bcu and Thomas Sailer:49 * reduced interrupt load in transmit case50 * reworked receiver51 * 0.7 03.08.1999 adapt to Linus' new __setup/__initcall52 * 0.8 10.08.1999 use module_init/module_exit53 * 0.9 12.02.2000 adapted to softnet driver interface54 * 0.10 03.07.2000 fix interface name handling55 */56 57/*****************************************************************************/58 59#include <linux/capability.h>60#include <linux/module.h>61#include <linux/ioport.h>62#include <linux/string.h>63#include <linux/init.h>64#include <linux/interrupt.h>65#include <linux/hdlcdrv.h>66#include <linux/baycom.h>67#include <linux/jiffies.h>68#include <linux/time64.h>69 70#include <linux/uaccess.h>71#include <asm/io.h>72#include <asm/irq.h>73 74/* --------------------------------------------------------------------- */75 76#define BAYCOM_DEBUG77 78/* --------------------------------------------------------------------- */79 80static const char bc_drvname[] = "baycom_ser_fdx";81static const char bc_drvinfo[] = KERN_INFO "baycom_ser_fdx: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"82"baycom_ser_fdx: version 0.10\n";83 84/* --------------------------------------------------------------------- */85 86#define NR_PORTS 487 88static struct net_device *baycom_device[NR_PORTS];89 90/* --------------------------------------------------------------------- */91 92#define RBR(iobase) (iobase+0)93#define THR(iobase) (iobase+0)94#define IER(iobase) (iobase+1)95#define IIR(iobase) (iobase+2)96#define FCR(iobase) (iobase+2)97#define LCR(iobase) (iobase+3)98#define MCR(iobase) (iobase+4)99#define LSR(iobase) (iobase+5)100#define MSR(iobase) (iobase+6)101#define SCR(iobase) (iobase+7)102#define DLL(iobase) (iobase+0)103#define DLM(iobase) (iobase+1)104 105#define SER12_EXTENT 8106 107/* ---------------------------------------------------------------------- */108/*109 * Information that need to be kept for each board.110 */111 112struct baycom_state {113 struct hdlcdrv_state hdrv;114 115 unsigned int baud, baud_us, baud_arbdiv, baud_uartdiv, baud_dcdtimeout;116 int opt_dcd;117 118 struct modem_state {119 unsigned char flags;120 unsigned char ptt;121 unsigned int shreg;122 struct modem_state_ser12 {123 unsigned char tx_bit;124 unsigned char last_rxbit;125 int dcd_sum0, dcd_sum1, dcd_sum2;126 int dcd_time;127 unsigned int pll_time;128 unsigned int txshreg;129 } ser12;130 } modem;131 132#ifdef BAYCOM_DEBUG133 struct debug_vals {134 unsigned long last_jiffies;135 unsigned cur_intcnt;136 unsigned last_intcnt;137 int cur_pllcorr;138 int last_pllcorr;139 } debug_vals;140#endif /* BAYCOM_DEBUG */141};142 143/* --------------------------------------------------------------------- */144 145static inline void baycom_int_freq(struct baycom_state *bc)146{147#ifdef BAYCOM_DEBUG148 unsigned long cur_jiffies = jiffies;149 /*150 * measure the interrupt frequency151 */152 bc->debug_vals.cur_intcnt++;153 if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) {154 bc->debug_vals.last_jiffies = cur_jiffies;155 bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;156 bc->debug_vals.cur_intcnt = 0;157 bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;158 bc->debug_vals.cur_pllcorr = 0;159 }160#endif /* BAYCOM_DEBUG */161}162 163/* --------------------------------------------------------------------- */164/*165 * ===================== SER12 specific routines =========================166 */167 168/* --------------------------------------------------------------------- */169 170static inline void ser12_set_divisor(struct net_device *dev,171 unsigned int divisor)172{173 outb(0x81, LCR(dev->base_addr)); /* DLAB = 1 */174 outb(divisor, DLL(dev->base_addr));175 outb(divisor >> 8, DLM(dev->base_addr));176 outb(0x01, LCR(dev->base_addr)); /* word length = 6 */177 /*178 * make sure the next interrupt is generated;179 * 0 must be used to power the modem; the modem draws its180 * power from the TxD line181 */182 outb(0x00, THR(dev->base_addr));183 /*184 * it is important not to set the divider while transmitting;185 * this reportedly makes some UARTs generating interrupts186 * in the hundredthousands per second region187 * Reported by: Ignacio.Arenaza@studi.epfl.ch (Ignacio Arenaza Nuno)188 */189}190 191static __inline__ void ser12_rx(struct net_device *dev, struct baycom_state *bc, struct timespec64 *ts, unsigned char curs)192{193 int timediff;194 int bdus8 = bc->baud_us >> 3;195 int bdus4 = bc->baud_us >> 2;196 int bdus2 = bc->baud_us >> 1;197 198 timediff = 1000000 + ts->tv_nsec / NSEC_PER_USEC -199 bc->modem.ser12.pll_time;200 while (timediff >= 500000)201 timediff -= 1000000;202 while (timediff >= bdus2) {203 timediff -= bc->baud_us;204 bc->modem.ser12.pll_time += bc->baud_us;205 bc->modem.ser12.dcd_time--;206 /* first check if there is room to add a bit */207 if (bc->modem.shreg & 1) {208 hdlcdrv_putbits(&bc->hdrv, (bc->modem.shreg >> 1) ^ 0xffff);209 bc->modem.shreg = 0x10000;210 }211 /* add a one bit */212 bc->modem.shreg >>= 1;213 }214 if (bc->modem.ser12.dcd_time <= 0) {215 if (!bc->opt_dcd)216 hdlcdrv_setdcd(&bc->hdrv, (bc->modem.ser12.dcd_sum0 + 217 bc->modem.ser12.dcd_sum1 + 218 bc->modem.ser12.dcd_sum2) < 0);219 bc->modem.ser12.dcd_sum2 = bc->modem.ser12.dcd_sum1;220 bc->modem.ser12.dcd_sum1 = bc->modem.ser12.dcd_sum0;221 bc->modem.ser12.dcd_sum0 = 2; /* slight bias */222 bc->modem.ser12.dcd_time += 120;223 }224 if (bc->modem.ser12.last_rxbit != curs) {225 bc->modem.ser12.last_rxbit = curs;226 bc->modem.shreg |= 0x10000;227 /* adjust the PLL */228 if (timediff > 0)229 bc->modem.ser12.pll_time += bdus8;230 else231 bc->modem.ser12.pll_time += 1000000 - bdus8;232 /* update DCD */233 if (abs(timediff) > bdus4)234 bc->modem.ser12.dcd_sum0 += 4;235 else236 bc->modem.ser12.dcd_sum0--;237#ifdef BAYCOM_DEBUG238 bc->debug_vals.cur_pllcorr = timediff;239#endif /* BAYCOM_DEBUG */240 }241 while (bc->modem.ser12.pll_time >= 1000000)242 bc->modem.ser12.pll_time -= 1000000;243}244 245/* --------------------------------------------------------------------- */246 247static irqreturn_t ser12_interrupt(int irq, void *dev_id)248{249 struct net_device *dev = (struct net_device *)dev_id;250 struct baycom_state *bc = netdev_priv(dev);251 struct timespec64 ts;252 unsigned char iir, msr;253 unsigned int txcount = 0;254 255 if (!bc || bc->hdrv.magic != HDLCDRV_MAGIC)256 return IRQ_NONE;257 /* fast way out for shared irq */258 if ((iir = inb(IIR(dev->base_addr))) & 1) 259 return IRQ_NONE;260 /* get current time */261 ktime_get_ts64(&ts);262 msr = inb(MSR(dev->base_addr));263 /* delta DCD */264 if ((msr & 8) && bc->opt_dcd)265 hdlcdrv_setdcd(&bc->hdrv, !((msr ^ bc->opt_dcd) & 0x80));266 do {267 switch (iir & 6) {268 case 6:269 inb(LSR(dev->base_addr));270 break;271 272 case 4:273 inb(RBR(dev->base_addr));274 break;275 276 case 2:277 /*278 * make sure the next interrupt is generated;279 * 0 must be used to power the modem; the modem draws its280 * power from the TxD line281 */282 outb(0x00, THR(dev->base_addr));283 baycom_int_freq(bc);284 txcount++;285 /*286 * first output the last bit (!) then call HDLC transmitter,287 * since this may take quite long288 */289 if (bc->modem.ptt)290 outb(0x0e | (!!bc->modem.ser12.tx_bit), MCR(dev->base_addr));291 else292 outb(0x0d, MCR(dev->base_addr)); /* transmitter off */293 break;294 295 default:296 msr = inb(MSR(dev->base_addr));297 /* delta DCD */298 if ((msr & 8) && bc->opt_dcd) 299 hdlcdrv_setdcd(&bc->hdrv, !((msr ^ bc->opt_dcd) & 0x80));300 break;301 }302 iir = inb(IIR(dev->base_addr));303 } while (!(iir & 1));304 ser12_rx(dev, bc, &ts, msr & 0x10); /* CTS */305 if (bc->modem.ptt && txcount) {306 if (bc->modem.ser12.txshreg <= 1) {307 bc->modem.ser12.txshreg = 0x10000 | hdlcdrv_getbits(&bc->hdrv);308 if (!hdlcdrv_ptt(&bc->hdrv)) {309 ser12_set_divisor(dev, 115200/100/8);310 bc->modem.ptt = 0;311 goto end_transmit;312 }313 }314 bc->modem.ser12.tx_bit = !(bc->modem.ser12.tx_bit ^ (bc->modem.ser12.txshreg & 1));315 bc->modem.ser12.txshreg >>= 1;316 }317 end_transmit:318 local_irq_enable();319 if (!bc->modem.ptt && txcount) {320 hdlcdrv_arbitrate(dev, &bc->hdrv);321 if (hdlcdrv_ptt(&bc->hdrv)) {322 ser12_set_divisor(dev, bc->baud_uartdiv);323 bc->modem.ser12.txshreg = 1;324 bc->modem.ptt = 1;325 }326 }327 hdlcdrv_transmitter(dev, &bc->hdrv);328 hdlcdrv_receiver(dev, &bc->hdrv);329 local_irq_disable();330 return IRQ_HANDLED;331}332 333/* --------------------------------------------------------------------- */334 335enum uart { c_uart_unknown, c_uart_8250,336 c_uart_16450, c_uart_16550, c_uart_16550A};337static const char *uart_str[] = { 338 "unknown", "8250", "16450", "16550", "16550A" 339};340 341static enum uart ser12_check_uart(unsigned int iobase)342{343 unsigned char b1,b2,b3;344 enum uart u;345 enum uart uart_tab[] =346 { c_uart_16450, c_uart_unknown, c_uart_16550, c_uart_16550A };347 348 b1 = inb(MCR(iobase));349 outb(b1 | 0x10, MCR(iobase)); /* loopback mode */350 b2 = inb(MSR(iobase));351 outb(0x1a, MCR(iobase));352 b3 = inb(MSR(iobase)) & 0xf0;353 outb(b1, MCR(iobase)); /* restore old values */354 outb(b2, MSR(iobase));355 if (b3 != 0x90)356 return c_uart_unknown;357 inb(RBR(iobase));358 inb(RBR(iobase));359 outb(0x01, FCR(iobase)); /* enable FIFOs */360 u = uart_tab[(inb(IIR(iobase)) >> 6) & 3];361 if (u == c_uart_16450) {362 outb(0x5a, SCR(iobase));363 b1 = inb(SCR(iobase));364 outb(0xa5, SCR(iobase));365 b2 = inb(SCR(iobase));366 if ((b1 != 0x5a) || (b2 != 0xa5))367 u = c_uart_8250;368 }369 return u;370}371 372/* --------------------------------------------------------------------- */373 374static int ser12_open(struct net_device *dev)375{376 struct baycom_state *bc = netdev_priv(dev);377 enum uart u;378 379 if (!dev || !bc)380 return -ENXIO;381 if (!dev->base_addr || dev->base_addr > 0xffff-SER12_EXTENT ||382 dev->irq < 2 || dev->irq > nr_irqs) {383 printk(KERN_INFO "baycom_ser_fdx: invalid portnumber (max %u) "384 "or irq (2 <= irq <= %d)\n",385 0xffff-SER12_EXTENT, nr_irqs);386 return -ENXIO;387 }388 if (bc->baud < 300 || bc->baud > 4800) {389 printk(KERN_INFO "baycom_ser_fdx: invalid baudrate "390 "(300...4800)\n");391 return -EINVAL;392 }393 if (!request_region(dev->base_addr, SER12_EXTENT, "baycom_ser_fdx")) {394 printk(KERN_WARNING "BAYCOM_SER_FSX: I/O port 0x%04lx busy\n",395 dev->base_addr);396 return -EACCES;397 }398 memset(&bc->modem, 0, sizeof(bc->modem));399 bc->hdrv.par.bitrate = bc->baud;400 bc->baud_us = 1000000/bc->baud;401 bc->baud_uartdiv = (115200/8)/bc->baud;402 if ((u = ser12_check_uart(dev->base_addr)) == c_uart_unknown){403 release_region(dev->base_addr, SER12_EXTENT);404 return -EIO;405 }406 outb(0, FCR(dev->base_addr)); /* disable FIFOs */407 outb(0x0d, MCR(dev->base_addr));408 outb(0, IER(dev->base_addr));409 if (request_irq(dev->irq, ser12_interrupt, IRQF_SHARED,410 "baycom_ser_fdx", dev)) {411 release_region(dev->base_addr, SER12_EXTENT);412 return -EBUSY;413 }414 /*415 * set the SIO to 6 Bits/character; during receive,416 * the baud rate is set to produce 100 ints/sec417 * to feed the channel arbitration process,418 * during transmit to baud ints/sec to run419 * the transmitter420 */421 ser12_set_divisor(dev, 115200/100/8);422 /*423 * enable transmitter empty interrupt and modem status interrupt424 */425 outb(0x0a, IER(dev->base_addr));426 /*427 * make sure the next interrupt is generated;428 * 0 must be used to power the modem; the modem draws its429 * power from the TxD line430 */431 outb(0x00, THR(dev->base_addr));432 hdlcdrv_setdcd(&bc->hdrv, 0);433 printk(KERN_INFO "%s: ser_fdx at iobase 0x%lx irq %u baud %u uart %s\n",434 bc_drvname, dev->base_addr, dev->irq, bc->baud, uart_str[u]);435 return 0;436}437 438/* --------------------------------------------------------------------- */439 440static int ser12_close(struct net_device *dev)441{442 struct baycom_state *bc = netdev_priv(dev);443 444 if (!dev || !bc)445 return -EINVAL;446 /*447 * disable interrupts448 */449 outb(0, IER(dev->base_addr));450 outb(1, MCR(dev->base_addr));451 free_irq(dev->irq, dev);452 release_region(dev->base_addr, SER12_EXTENT);453 printk(KERN_INFO "%s: close ser_fdx at iobase 0x%lx irq %u\n",454 bc_drvname, dev->base_addr, dev->irq);455 return 0;456}457 458/* --------------------------------------------------------------------- */459/*460 * ===================== hdlcdrv driver interface =========================461 */462 463/* --------------------------------------------------------------------- */464 465static int baycom_ioctl(struct net_device *dev, void __user *data,466 struct hdlcdrv_ioctl *hi, int cmd);467 468/* --------------------------------------------------------------------- */469 470static const struct hdlcdrv_ops ser12_ops = {471 .drvname = bc_drvname,472 .drvinfo = bc_drvinfo,473 .open = ser12_open,474 .close = ser12_close,475 .ioctl = baycom_ioctl,476};477 478/* --------------------------------------------------------------------- */479 480static int baycom_setmode(struct baycom_state *bc, const char *modestr)481{482 unsigned int baud;483 484 if (!strncmp(modestr, "ser", 3)) {485 baud = simple_strtoul(modestr+3, NULL, 10);486 if (baud >= 3 && baud <= 48)487 bc->baud = baud*100;488 }489 if (strchr(modestr, '*'))490 bc->opt_dcd = 0;491 else if (strchr(modestr, '+'))492 bc->opt_dcd = -1;493 else494 bc->opt_dcd = 1;495 return 0;496}497 498/* --------------------------------------------------------------------- */499 500static int baycom_ioctl(struct net_device *dev, void __user *data,501 struct hdlcdrv_ioctl *hi, int cmd)502{503 struct baycom_state *bc;504 struct baycom_ioctl bi;505 506 if (!dev)507 return -EINVAL;508 509 bc = netdev_priv(dev);510 BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC);511 512 if (cmd != SIOCDEVPRIVATE)513 return -ENOIOCTLCMD;514 switch (hi->cmd) {515 default:516 break;517 518 case HDLCDRVCTL_GETMODE:519 sprintf(hi->data.modename, "ser%u", bc->baud / 100);520 if (bc->opt_dcd <= 0)521 strcat(hi->data.modename, (!bc->opt_dcd) ? "*" : "+");522 if (copy_to_user(data, hi, sizeof(struct hdlcdrv_ioctl)))523 return -EFAULT;524 return 0;525 526 case HDLCDRVCTL_SETMODE:527 if (netif_running(dev) || !capable(CAP_NET_ADMIN))528 return -EACCES;529 hi->data.modename[sizeof(hi->data.modename)-1] = '\0';530 return baycom_setmode(bc, hi->data.modename);531 532 case HDLCDRVCTL_MODELIST:533 strcpy(hi->data.modename, "ser12,ser3,ser24");534 if (copy_to_user(data, hi, sizeof(struct hdlcdrv_ioctl)))535 return -EFAULT;536 return 0;537 538 case HDLCDRVCTL_MODEMPARMASK:539 return HDLCDRV_PARMASK_IOBASE | HDLCDRV_PARMASK_IRQ;540 541 }542 543 if (copy_from_user(&bi, data, sizeof(bi)))544 return -EFAULT;545 switch (bi.cmd) {546 default:547 return -ENOIOCTLCMD;548 549#ifdef BAYCOM_DEBUG550 case BAYCOMCTL_GETDEBUG:551 bi.data.dbg.debug1 = bc->hdrv.ptt_keyed;552 bi.data.dbg.debug2 = bc->debug_vals.last_intcnt;553 bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr;554 break;555#endif /* BAYCOM_DEBUG */556 557 }558 if (copy_to_user(data, &bi, sizeof(bi)))559 return -EFAULT;560 return 0;561 562}563 564/* --------------------------------------------------------------------- */565 566/*567 * command line settable parameters568 */569static char *mode[NR_PORTS] = { "ser12*", };570static int iobase[NR_PORTS] = { 0x3f8, };571static int irq[NR_PORTS] = { 4, };572static int baud[NR_PORTS] = { [0 ... NR_PORTS-1] = 1200 };573 574module_param_array(mode, charp, NULL, 0);575MODULE_PARM_DESC(mode, "baycom operating mode; * for software DCD");576module_param_hw_array(iobase, int, ioport, NULL, 0);577MODULE_PARM_DESC(iobase, "baycom io base address");578module_param_hw_array(irq, int, irq, NULL, 0);579MODULE_PARM_DESC(irq, "baycom irq number");580module_param_array(baud, int, NULL, 0);581MODULE_PARM_DESC(baud, "baycom baud rate (300 to 4800)");582 583MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");584MODULE_DESCRIPTION("Baycom ser12 full duplex amateur radio modem driver");585MODULE_LICENSE("GPL");586 587/* --------------------------------------------------------------------- */588 589static int __init init_baycomserfdx(void)590{591 int i, found = 0;592 char set_hw = 1;593 594 printk(bc_drvinfo);595 /*596 * register net devices597 */598 for (i = 0; i < NR_PORTS; i++) {599 struct net_device *dev;600 struct baycom_state *bc;601 char ifname[IFNAMSIZ];602 603 sprintf(ifname, "bcsf%d", i);604 605 if (!mode[i])606 set_hw = 0;607 if (!set_hw)608 iobase[i] = irq[i] = 0;609 610 dev = hdlcdrv_register(&ser12_ops, 611 sizeof(struct baycom_state),612 ifname, iobase[i], irq[i], 0);613 if (IS_ERR(dev)) 614 break;615 616 bc = netdev_priv(dev);617 if (set_hw && baycom_setmode(bc, mode[i]))618 set_hw = 0;619 bc->baud = baud[i];620 found++;621 baycom_device[i] = dev;622 }623 624 if (!found)625 return -ENXIO;626 return 0;627}628 629static void __exit cleanup_baycomserfdx(void)630{631 int i;632 633 for(i = 0; i < NR_PORTS; i++) {634 struct net_device *dev = baycom_device[i];635 if (dev) 636 hdlcdrv_unregister(dev);637 }638}639 640module_init(init_baycomserfdx);641module_exit(cleanup_baycomserfdx);642 643/* --------------------------------------------------------------------- */644 645#ifndef MODULE646 647/*648 * format: baycom_ser_fdx=io,irq,mode649 * mode: ser# hardware DCD650 * ser#* software DCD651 * ser#+ hardware DCD, inverted signal at DCD pin652 * '#' denotes the baud rate / 100, eg. ser12* is '1200 baud, soft DCD'653 */654 655static int __init baycom_ser_fdx_setup(char *str)656{657 static unsigned nr_dev;658 int ints[4];659 660 if (nr_dev >= NR_PORTS)661 return 0;662 str = get_options(str, 4, ints);663 if (ints[0] < 2)664 return 0;665 mode[nr_dev] = str;666 iobase[nr_dev] = ints[1];667 irq[nr_dev] = ints[2];668 if (ints[0] >= 3)669 baud[nr_dev] = ints[3];670 nr_dev++;671 return 1;672}673 674__setup("baycom_ser_fdx=", baycom_ser_fdx_setup);675 676#endif /* MODULE */677/* --------------------------------------------------------------------- */678