linux/drivers/net/wan/n2.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * SDL Inc. RISCom/N2 synchronous serial card driver for Linux
   4 *
   5 * Copyright (C) 1998-2003 Krzysztof Halasa <khc@pm.waw.pl>
   6 *
   7 * For information see <https://www.kernel.org/pub/linux/utils/net/hdlc/>
   8 *
   9 * Note: integrated CSU/DSU/DDS are not supported by this driver
  10 *
  11 * Sources of information:
  12 *    Hitachi HD64570 SCA User's Manual
  13 *    SDL Inc. PPP/HDLC/CISCO driver
  14 */
  15
  16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18#include <linux/module.h>
  19#include <linux/kernel.h>
  20#include <linux/capability.h>
  21#include <linux/slab.h>
  22#include <linux/types.h>
  23#include <linux/fcntl.h>
  24#include <linux/in.h>
  25#include <linux/string.h>
  26#include <linux/errno.h>
  27#include <linux/init.h>
  28#include <linux/ioport.h>
  29#include <linux/moduleparam.h>
  30#include <linux/netdevice.h>
  31#include <linux/hdlc.h>
  32#include <asm/io.h>
  33#include "hd64570.h"
  34
  35
  36static const char* version = "SDL RISCom/N2 driver version: 1.15";
  37static const char* devname = "RISCom/N2";
  38
  39#undef DEBUG_PKT
  40#define DEBUG_RINGS
  41
  42#define USE_WINDOWSIZE 16384
  43#define USE_BUS16BITS 1
  44#define CLOCK_BASE 9830400      /* 9.8304 MHz */
  45#define MAX_PAGES      16       /* 16 RAM pages at max */
  46#define MAX_RAM_SIZE 0x80000    /* 512 KB */
  47#if MAX_RAM_SIZE > MAX_PAGES * USE_WINDOWSIZE
  48#undef MAX_RAM_SIZE
  49#define MAX_RAM_SIZE (MAX_PAGES * USE_WINDOWSIZE)
  50#endif
  51#define N2_IOPORTS 0x10
  52#define NEED_DETECT_RAM
  53#define NEED_SCA_MSCI_INTR
  54#define MAX_TX_BUFFERS 10
  55
  56static char *hw;        /* pointer to hw=xxx command line string */
  57
  58/* RISCom/N2 Board Registers */
  59
  60/* PC Control Register */
  61#define N2_PCR 0
  62#define PCR_RUNSCA 1     /* Run 64570 */
  63#define PCR_VPM    2     /* Enable VPM - needed if using RAM above 1 MB */
  64#define PCR_ENWIN  4     /* Open window */
  65#define PCR_BUS16  8     /* 16-bit bus */
  66
  67
  68/* Memory Base Address Register */
  69#define N2_BAR 2
  70
  71
  72/* Page Scan Register  */
  73#define N2_PSR 4
  74#define WIN16K       0x00
  75#define WIN32K       0x20
  76#define WIN64K       0x40
  77#define PSR_WINBITS  0x60
  78#define PSR_DMAEN    0x80
  79#define PSR_PAGEBITS 0x0F
  80
  81
  82/* Modem Control Reg */
  83#define N2_MCR 6
  84#define CLOCK_OUT_PORT1 0x80
  85#define CLOCK_OUT_PORT0 0x40
  86#define TX422_PORT1     0x20
  87#define TX422_PORT0     0x10
  88#define DSR_PORT1       0x08
  89#define DSR_PORT0       0x04
  90#define DTR_PORT1       0x02
  91#define DTR_PORT0       0x01
  92
  93
  94typedef struct port_s {
  95        struct net_device *dev;
  96        struct card_s *card;
  97        spinlock_t lock;        /* TX lock */
  98        sync_serial_settings settings;
  99        int valid;              /* port enabled */
 100        int rxpart;             /* partial frame received, next frame invalid*/
 101        unsigned short encoding;
 102        unsigned short parity;
 103        u16 rxin;               /* rx ring buffer 'in' pointer */
 104        u16 txin;               /* tx ring buffer 'in' and 'last' pointers */
 105        u16 txlast;
 106        u8 rxs, txs, tmc;       /* SCA registers */
 107        u8 phy_node;            /* physical port # - 0 or 1 */
 108        u8 log_node;            /* logical port # */
 109}port_t;
 110
 111
 112
 113typedef struct card_s {
 114        u8 __iomem *winbase;            /* ISA window base address */
 115        u32 phy_winbase;        /* ISA physical base address */
 116        u32 ram_size;           /* number of bytes */
 117        u16 io;                 /* IO Base address */
 118        u16 buff_offset;        /* offset of first buffer of first channel */
 119        u16 rx_ring_buffers;    /* number of buffers in a ring */
 120        u16 tx_ring_buffers;
 121        u8 irq;                 /* IRQ (3-15) */
 122
 123        port_t ports[2];
 124        struct card_s *next_card;
 125}card_t;
 126
 127
 128static card_t *first_card;
 129static card_t **new_card = &first_card;
 130
 131
 132#define sca_reg(reg, card) (0x8000 | (card)->io | \
 133                            ((reg) & 0x0F) | (((reg) & 0xF0) << 6))
 134#define sca_in(reg, card)               inb(sca_reg(reg, card))
 135#define sca_out(value, reg, card)       outb(value, sca_reg(reg, card))
 136#define sca_inw(reg, card)              inw(sca_reg(reg, card))
 137#define sca_outw(value, reg, card)      outw(value, sca_reg(reg, card))
 138
 139#define port_to_card(port)              ((port)->card)
 140#define log_node(port)                  ((port)->log_node)
 141#define phy_node(port)                  ((port)->phy_node)
 142#define winsize(card)                   (USE_WINDOWSIZE)
 143#define winbase(card)                   ((card)->winbase)
 144#define get_port(card, port)            ((card)->ports[port].valid ? \
 145                                         &(card)->ports[port] : NULL)
 146
 147
 148static __inline__ u8 sca_get_page(card_t *card)
 149{
 150        return inb(card->io + N2_PSR) & PSR_PAGEBITS;
 151}
 152
 153
 154static __inline__ void openwin(card_t *card, u8 page)
 155{
 156        u8 psr = inb(card->io + N2_PSR);
 157        outb((psr & ~PSR_PAGEBITS) | page, card->io + N2_PSR);
 158}
 159
 160
 161#include "hd64570.c"
 162
 163
 164static void n2_set_iface(port_t *port)
 165{
 166        card_t *card = port->card;
 167        int io = card->io;
 168        u8 mcr = inb(io + N2_MCR);
 169        u8 msci = get_msci(port);
 170        u8 rxs = port->rxs & CLK_BRG_MASK;
 171        u8 txs = port->txs & CLK_BRG_MASK;
 172
 173        switch(port->settings.clock_type) {
 174        case CLOCK_INT:
 175                mcr |= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
 176                rxs |= CLK_BRG_RX; /* BRG output */
 177                txs |= CLK_RXCLK_TX; /* RX clock */
 178                break;
 179
 180        case CLOCK_TXINT:
 181                mcr |= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
 182                rxs |= CLK_LINE_RX; /* RXC input */
 183                txs |= CLK_BRG_TX; /* BRG output */
 184                break;
 185
 186        case CLOCK_TXFROMRX:
 187                mcr |= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
 188                rxs |= CLK_LINE_RX; /* RXC input */
 189                txs |= CLK_RXCLK_TX; /* RX clock */
 190                break;
 191
 192        default:                /* Clock EXTernal */
 193                mcr &= port->phy_node ? ~CLOCK_OUT_PORT1 : ~CLOCK_OUT_PORT0;
 194                rxs |= CLK_LINE_RX; /* RXC input */
 195                txs |= CLK_LINE_TX; /* TXC input */
 196        }
 197
 198        outb(mcr, io + N2_MCR);
 199        port->rxs = rxs;
 200        port->txs = txs;
 201        sca_out(rxs, msci + RXS, card);
 202        sca_out(txs, msci + TXS, card);
 203        sca_set_port(port);
 204}
 205
 206
 207
 208static int n2_open(struct net_device *dev)
 209{
 210        port_t *port = dev_to_port(dev);
 211        int io = port->card->io;
 212        u8 mcr = inb(io + N2_MCR) | (port->phy_node ? TX422_PORT1:TX422_PORT0);
 213        int result;
 214
 215        result = hdlc_open(dev);
 216        if (result)
 217                return result;
 218
 219        mcr &= port->phy_node ? ~DTR_PORT1 : ~DTR_PORT0; /* set DTR ON */
 220        outb(mcr, io + N2_MCR);
 221
 222        outb(inb(io + N2_PCR) | PCR_ENWIN, io + N2_PCR); /* open window */
 223        outb(inb(io + N2_PSR) | PSR_DMAEN, io + N2_PSR); /* enable dma */
 224        sca_open(dev);
 225        n2_set_iface(port);
 226        return 0;
 227}
 228
 229
 230
 231static int n2_close(struct net_device *dev)
 232{
 233        port_t *port = dev_to_port(dev);
 234        int io = port->card->io;
 235        u8 mcr = inb(io+N2_MCR) | (port->phy_node ? TX422_PORT1 : TX422_PORT0);
 236
 237        sca_close(dev);
 238        mcr |= port->phy_node ? DTR_PORT1 : DTR_PORT0; /* set DTR OFF */
 239        outb(mcr, io + N2_MCR);
 240        hdlc_close(dev);
 241        return 0;
 242}
 243
 244
 245
 246static int n2_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 247{
 248        const size_t size = sizeof(sync_serial_settings);
 249        sync_serial_settings new_line;
 250        sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
 251        port_t *port = dev_to_port(dev);
 252
 253#ifdef DEBUG_RINGS
 254        if (cmd == SIOCDEVPRIVATE) {
 255                sca_dump_rings(dev);
 256                return 0;
 257        }
 258#endif
 259        if (cmd != SIOCWANDEV)
 260                return hdlc_ioctl(dev, ifr, cmd);
 261
 262        switch(ifr->ifr_settings.type) {
 263        case IF_GET_IFACE:
 264                ifr->ifr_settings.type = IF_IFACE_SYNC_SERIAL;
 265                if (ifr->ifr_settings.size < size) {
 266                        ifr->ifr_settings.size = size; /* data size wanted */
 267                        return -ENOBUFS;
 268                }
 269                if (copy_to_user(line, &port->settings, size))
 270                        return -EFAULT;
 271                return 0;
 272
 273        case IF_IFACE_SYNC_SERIAL:
 274                if(!capable(CAP_NET_ADMIN))
 275                        return -EPERM;
 276
 277                if (copy_from_user(&new_line, line, size))
 278                        return -EFAULT;
 279
 280                if (new_line.clock_type != CLOCK_EXT &&
 281                    new_line.clock_type != CLOCK_TXFROMRX &&
 282                    new_line.clock_type != CLOCK_INT &&
 283                    new_line.clock_type != CLOCK_TXINT)
 284                        return -EINVAL; /* No such clock setting */
 285
 286                if (new_line.loopback != 0 && new_line.loopback != 1)
 287                        return -EINVAL;
 288
 289                memcpy(&port->settings, &new_line, size); /* Update settings */
 290                n2_set_iface(port);
 291                return 0;
 292
 293        default:
 294                return hdlc_ioctl(dev, ifr, cmd);
 295        }
 296}
 297
 298
 299
 300static void n2_destroy_card(card_t *card)
 301{
 302        int cnt;
 303
 304        for (cnt = 0; cnt < 2; cnt++)
 305                if (card->ports[cnt].card) {
 306                        struct net_device *dev = port_to_dev(&card->ports[cnt]);
 307                        unregister_hdlc_device(dev);
 308                }
 309
 310        if (card->irq)
 311                free_irq(card->irq, card);
 312
 313        if (card->winbase) {
 314                iounmap(card->winbase);
 315                release_mem_region(card->phy_winbase, USE_WINDOWSIZE);
 316        }
 317
 318        if (card->io)
 319                release_region(card->io, N2_IOPORTS);
 320        if (card->ports[0].dev)
 321                free_netdev(card->ports[0].dev);
 322        if (card->ports[1].dev)
 323                free_netdev(card->ports[1].dev);
 324        kfree(card);
 325}
 326
 327static const struct net_device_ops n2_ops = {
 328        .ndo_open       = n2_open,
 329        .ndo_stop       = n2_close,
 330        .ndo_start_xmit = hdlc_start_xmit,
 331        .ndo_do_ioctl   = n2_ioctl,
 332};
 333
 334static int __init n2_run(unsigned long io, unsigned long irq,
 335                         unsigned long winbase, long valid0, long valid1)
 336{
 337        card_t *card;
 338        u8 cnt, pcr;
 339        int i;
 340
 341        if (io < 0x200 || io > 0x3FF || (io % N2_IOPORTS) != 0) {
 342                pr_err("invalid I/O port value\n");
 343                return -ENODEV;
 344        }
 345
 346        if (irq < 3 || irq > 15 || irq == 6) /* FIXME */ {
 347                pr_err("invalid IRQ value\n");
 348                return -ENODEV;
 349        }
 350
 351        if (winbase < 0xA0000 || winbase > 0xFFFFF || (winbase & 0xFFF) != 0) {
 352                pr_err("invalid RAM value\n");
 353                return -ENODEV;
 354        }
 355
 356        card = kzalloc(sizeof(card_t), GFP_KERNEL);
 357        if (card == NULL)
 358                return -ENOBUFS;
 359
 360        card->ports[0].dev = alloc_hdlcdev(&card->ports[0]);
 361        card->ports[1].dev = alloc_hdlcdev(&card->ports[1]);
 362        if (!card->ports[0].dev || !card->ports[1].dev) {
 363                pr_err("unable to allocate memory\n");
 364                n2_destroy_card(card);
 365                return -ENOMEM;
 366        }
 367
 368        if (!request_region(io, N2_IOPORTS, devname)) {
 369                pr_err("I/O port region in use\n");
 370                n2_destroy_card(card);
 371                return -EBUSY;
 372        }
 373        card->io = io;
 374
 375        if (request_irq(irq, sca_intr, 0, devname, card)) {
 376                pr_err("could not allocate IRQ\n");
 377                n2_destroy_card(card);
 378                return -EBUSY;
 379        }
 380        card->irq = irq;
 381
 382        if (!request_mem_region(winbase, USE_WINDOWSIZE, devname)) {
 383                pr_err("could not request RAM window\n");
 384                n2_destroy_card(card);
 385                return -EBUSY;
 386        }
 387        card->phy_winbase = winbase;
 388        card->winbase = ioremap(winbase, USE_WINDOWSIZE);
 389        if (!card->winbase) {
 390                pr_err("ioremap() failed\n");
 391                n2_destroy_card(card);
 392                return -EFAULT;
 393        }
 394
 395        outb(0, io + N2_PCR);
 396        outb(winbase >> 12, io + N2_BAR);
 397
 398        switch (USE_WINDOWSIZE) {
 399        case 16384:
 400                outb(WIN16K, io + N2_PSR);
 401                break;
 402
 403        case 32768:
 404                outb(WIN32K, io + N2_PSR);
 405                break;
 406
 407        case 65536:
 408                outb(WIN64K, io + N2_PSR);
 409                break;
 410
 411        default:
 412                pr_err("invalid window size\n");
 413                n2_destroy_card(card);
 414                return -ENODEV;
 415        }
 416
 417        pcr = PCR_ENWIN | PCR_VPM | (USE_BUS16BITS ? PCR_BUS16 : 0);
 418        outb(pcr, io + N2_PCR);
 419
 420        card->ram_size = sca_detect_ram(card, card->winbase, MAX_RAM_SIZE);
 421
 422        /* number of TX + RX buffers for one port */
 423        i = card->ram_size / ((valid0 + valid1) * (sizeof(pkt_desc) +
 424                                                   HDLC_MAX_MRU));
 425
 426        card->tx_ring_buffers = min(i / 2, MAX_TX_BUFFERS);
 427        card->rx_ring_buffers = i - card->tx_ring_buffers;
 428
 429        card->buff_offset = (valid0 + valid1) * sizeof(pkt_desc) *
 430                (card->tx_ring_buffers + card->rx_ring_buffers);
 431
 432        pr_info("RISCom/N2 %u KB RAM, IRQ%u, using %u TX + %u RX packets rings\n",
 433                card->ram_size / 1024, card->irq,
 434                card->tx_ring_buffers, card->rx_ring_buffers);
 435
 436        if (card->tx_ring_buffers < 1) {
 437                pr_err("RAM test failed\n");
 438                n2_destroy_card(card);
 439                return -EIO;
 440        }
 441
 442        pcr |= PCR_RUNSCA;              /* run SCA */
 443        outb(pcr, io + N2_PCR);
 444        outb(0, io + N2_MCR);
 445
 446        sca_init(card, 0);
 447        for (cnt = 0; cnt < 2; cnt++) {
 448                port_t *port = &card->ports[cnt];
 449                struct net_device *dev = port_to_dev(port);
 450                hdlc_device *hdlc = dev_to_hdlc(dev);
 451
 452                if ((cnt == 0 && !valid0) || (cnt == 1 && !valid1))
 453                        continue;
 454
 455                port->phy_node = cnt;
 456                port->valid = 1;
 457
 458                if ((cnt == 1) && valid0)
 459                        port->log_node = 1;
 460
 461                spin_lock_init(&port->lock);
 462                dev->irq = irq;
 463                dev->mem_start = winbase;
 464                dev->mem_end = winbase + USE_WINDOWSIZE - 1;
 465                dev->tx_queue_len = 50;
 466                dev->netdev_ops = &n2_ops;
 467                hdlc->attach = sca_attach;
 468                hdlc->xmit = sca_xmit;
 469                port->settings.clock_type = CLOCK_EXT;
 470                port->card = card;
 471
 472                if (register_hdlc_device(dev)) {
 473                        pr_warn("unable to register hdlc device\n");
 474                        port->card = NULL;
 475                        n2_destroy_card(card);
 476                        return -ENOBUFS;
 477                }
 478                sca_init_port(port); /* Set up SCA memory */
 479
 480                netdev_info(dev, "RISCom/N2 node %d\n", port->phy_node);
 481        }
 482
 483        *new_card = card;
 484        new_card = &card->next_card;
 485
 486        return 0;
 487}
 488
 489
 490
 491static int __init n2_init(void)
 492{
 493        if (hw==NULL) {
 494#ifdef MODULE
 495                pr_info("no card initialized\n");
 496#endif
 497                return -EINVAL; /* no parameters specified, abort */
 498        }
 499
 500        pr_info("%s\n", version);
 501
 502        do {
 503                unsigned long io, irq, ram;
 504                long valid[2] = { 0, 0 }; /* Default = both ports disabled */
 505
 506                io = simple_strtoul(hw, &hw, 0);
 507
 508                if (*hw++ != ',')
 509                        break;
 510                irq = simple_strtoul(hw, &hw, 0);
 511
 512                if (*hw++ != ',')
 513                        break;
 514                ram = simple_strtoul(hw, &hw, 0);
 515
 516                if (*hw++ != ',')
 517                        break;
 518                while(1) {
 519                        if (*hw == '0' && !valid[0])
 520                                valid[0] = 1; /* Port 0 enabled */
 521                        else if (*hw == '1' && !valid[1])
 522                                valid[1] = 1; /* Port 1 enabled */
 523                        else
 524                                break;
 525                        hw++;
 526                }
 527
 528                if (!valid[0] && !valid[1])
 529                        break;  /* at least one port must be used */
 530
 531                if (*hw == ':' || *hw == '\x0')
 532                        n2_run(io, irq, ram, valid[0], valid[1]);
 533
 534                if (*hw == '\x0')
 535                        return first_card ? 0 : -EINVAL;
 536        }while(*hw++ == ':');
 537
 538        pr_err("invalid hardware parameters\n");
 539        return first_card ? 0 : -EINVAL;
 540}
 541
 542
 543static void __exit n2_cleanup(void)
 544{
 545        card_t *card = first_card;
 546
 547        while (card) {
 548                card_t *ptr = card;
 549                card = card->next_card;
 550                n2_destroy_card(ptr);
 551        }
 552}
 553
 554
 555module_init(n2_init);
 556module_exit(n2_cleanup);
 557
 558MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
 559MODULE_DESCRIPTION("RISCom/N2 serial port driver");
 560MODULE_LICENSE("GPL v2");
 561module_param(hw, charp, 0444);
 562MODULE_PARM_DESC(hw, "io,irq,ram,ports:io,irq,...");
 563