drivers/net/wan/dscc4.c

   1 /*
   2  * drivers/net/wan/dscc4/dscc4.c: a DSCC4 HDLC driver for Linux
   3  *
   4  * This software may be used and distributed according to the terms of the
   5  * GNU General Public License.
   6  *
   7  * The author may be reached as romieu@cogenit.fr.
   8  * Specific bug reports/asian food will be welcome.
   9  *
  10  * Special thanks to the nice people at CS-Telecom for the hardware and the
  11  * access to the test/measure tools.
  12  *
  13  *
  14  *                             Theory of Operation
  15  *
  16  * I. Board Compatibility
  17  *
  18  * This device driver is designed for the Siemens PEB20534 4 ports serial
  19  * controller as found on Etinc PCISYNC cards. The documentation for the
  20  * chipset is available at http://www.infineon.com:
  21  * - Data Sheet "DSCC4, DMA Supported Serial Communication Controller with
  22  * 4 Channels, PEB 20534 Version 2.1, PEF 20534 Version 2.1";
  23  * - Application Hint "Management of DSCC4 on-chip FIFO resources".
  24  * - Errata sheet DS5 (courtesy of Michael Skerritt).
  25  * Jens David has built an adapter based on the same chipset. Take a look
  26  * at http://www.afthd.tu-darmstadt.de/~dg1kjd/pciscc4 for a specific
  27  * driver.
  28  * Sample code (2 revisions) is available at Infineon.
  29  *
  30  * II. Board-specific settings
  31  *
  32  * Pcisync can transmit some clock signal to the outside world on the
  33  * *first two* ports provided you put a quartz and a line driver on it and
  34  * remove the jumpers. The operation is described on Etinc web site. If you
  35  * go DCE on these ports, don't forget to use an adequate cable.
  36  *
  37  * Sharing of the PCI interrupt line for this board is possible.
  38  *
  39  * III. Driver operation
  40  *
  41  * The rx/tx operations are based on a linked list of descriptors. The driver
  42  * doesn't use HOLD mode any more. HOLD mode is definitely buggy and the more
  43  * I tried to fix it, the more it started to look like (convoluted) software
  44  * mutation of LxDA method. Errata sheet DS5 suggests to use LxDA: consider
  45  * this a rfc2119 MUST.
  46  *
  47  * Tx direction
  48  * When the tx ring is full, the xmit routine issues a call to netdev_stop.
  49  * The device is supposed to be enabled again during an ALLS irq (we could
  50  * use HI but as it's easy to lose events, it's fscked).
  51  *
  52  * Rx direction
  53  * The received frames aren't supposed to span over multiple receiving areas.
  54  * I may implement it some day but it isn't the highest ranked item.
  55  *
  56  * IV. Notes
  57  * The current error (XDU, RFO) recovery code is untested.
  58  * So far, RDO takes his RX channel down and the right sequence to enable it
  59  * again is still a mistery. If RDO happens, plan a reboot. More details
  60  * in the code (NB: as this happens, TX still works).
  61  * Don't mess the cables during operation, especially on DTE ports. I don't
  62  * suggest it for DCE either but at least one can get some messages instead
  63  * of a complete instant freeze.
  64  * Tests are done on Rev. 20 of the silicium. The RDO handling changes with
  65  * the documentation/chipset releases.
  66  *
  67  * TODO:
  68  * - test X25.
  69  * - use polling at high irq/s,
  70  * - performance analysis,
  71  * - endianness.
  72  *
  73  * 2001/12/10   Daniela Squassoni  <daniela@cyclades.com>
  74  * - Contribution to support the new generic HDLC layer.
  75  *
  76  * 2002/01      Ueimor
  77  * - old style interface removal
  78  * - dscc4_release_ring fix (related to DMA mapping)
  79  * - hard_start_xmit fix (hint: TxSizeMax)
  80  * - misc crapectomy.
  81  */
  82
  83 #include <linux/module.h>
  84 #include <linux/sched.h>
  85 #include <linux/types.h>
  86 #include <linux/errno.h>
  87 #include <linux/list.h>
  88 #include <linux/ioport.h>
  89 #include <linux/pci.h>
  90 #include <linux/kernel.h>
  91 #include <linux/mm.h>
  92
  93 #include <asm/system.h>
  94 #include <asm/cache.h>
  95 #include <asm/byteorder.h>
  96 #include <asm/uaccess.h>
  97 #include <asm/io.h>
  98 #include <asm/irq.h>
  99
 100 #include <linux/init.h>
 101 #include <linux/string.h>
 102
 103 #include <linux/if_arp.h>
 104 #include <linux/netdevice.h>
 105 #include <linux/skbuff.h>
 106 #include <linux/delay.h>
 107 #include <linux/hdlc.h>
 108 #include <linux/mutex.h>
 109
 110 /* Version */
 111 static const char version[] = "$Id: dscc4.c,v 1.173 2003/09/20 23:55:34 romieu Exp $ for Linux\n";
 112 static int debug;
 113 static int quartz;
 114
 115 #ifdef CONFIG_DSCC4_PCI_RST
 116 static DEFINE_MUTEX(dscc4_mutex);
 117 static u32 dscc4_pci_config_store[16];
 118 #endif
 119
 120 #define DRV_NAME        "dscc4"
 121
 122 #undef DSCC4_POLLING
 123
 124 /* Module parameters */
 125
 126 MODULE_AUTHOR("Maintainer: Francois Romieu <romieu@cogenit.fr>");
 127 MODULE_DESCRIPTION("Siemens PEB20534 PCI Controler");
 128 MODULE_LICENSE("GPL");
 129 module_param(debug, int, 0);
 130 MODULE_PARM_DESC(debug,"Enable/disable extra messages");
 131 module_param(quartz, int, 0);
 132 MODULE_PARM_DESC(quartz,"If present, on-board quartz frequency (Hz)");
 133
 134 /* Structures */
 135
 136 struct thingie {
 137         int define;
 138         u32 bits;
 139 };
 140
 141 struct TxFD {
 142         __le32 state;
 143         __le32 next;
 144         __le32 data;
 145         __le32 complete;
 146         u32 jiffies; /* Allows sizeof(TxFD) == sizeof(RxFD) + extra hack */
 147                      /* FWIW, datasheet calls that "dummy" and says that card
 148                       * never looks at it; neither does the driver */
 149 };
 150
 151 struct RxFD {
 152         __le32 state1;
 153         __le32 next;
 154         __le32 data;
 155         __le32 state2;
 156         __le32 end;
 157 };
 158
 159 #define DUMMY_SKB_SIZE          64
 160 #define TX_LOW                  8
 161 #define TX_RING_SIZE            32
 162 #define RX_RING_SIZE            32
 163 #define TX_TOTAL_SIZE           TX_RING_SIZE*sizeof(struct TxFD)
 164 #define RX_TOTAL_SIZE           RX_RING_SIZE*sizeof(struct RxFD)
 165 #define IRQ_RING_SIZE           64              /* Keep it a multiple of 32 */
 166 #define TX_TIMEOUT              (HZ/10)
 167 #define DSCC4_HZ_MAX            33000000
 168 #define BRR_DIVIDER_MAX         64*0x00004000   /* Cf errata DS5 p.10 */
 169 #define dev_per_card            4
 170 #define SCC_REGISTERS_MAX       23              /* Cf errata DS5 p.4 */
 171
 172 #define SOURCE_ID(flags)        (((flags) >> 28) & 0x03)
 173 #define TO_SIZE(state)          (((state) >> 16) & 0x1fff)
 174
 175 /*
 176  * Given the operating range of Linux HDLC, the 2 defines below could be
 177  * made simpler. However they are a fine reminder for the limitations of
 178  * the driver: it's better to stay < TxSizeMax and < RxSizeMax.
 179  */
 180 #define TO_STATE_TX(len)        cpu_to_le32(((len) & TxSizeMax) << 16)
 181 #define TO_STATE_RX(len)        cpu_to_le32((RX_MAX(len) % RxSizeMax) << 16)
 182 #define RX_MAX(len)             ((((len) >> 5) + 1) << 5)       /* Cf RLCR */
 183 #define SCC_REG_START(dpriv)    (SCC_START+(dpriv->dev_id)*SCC_OFFSET)
 184
 185 struct dscc4_pci_priv {
 186         __le32 *iqcfg;
 187         int cfg_cur;
 188         spinlock_t lock;
 189         struct pci_dev *pdev;
 190
 191         struct dscc4_dev_priv *root;
 192         dma_addr_t iqcfg_dma;
 193         u32 xtal_hz;
 194 };
 195
 196 struct dscc4_dev_priv {
 197         struct sk_buff *rx_skbuff[RX_RING_SIZE];
 198         struct sk_buff *tx_skbuff[TX_RING_SIZE];
 199
 200         struct RxFD *rx_fd;
 201         struct TxFD *tx_fd;
 202         __le32 *iqrx;
 203         __le32 *iqtx;
 204
 205         /* FIXME: check all the volatile are required */
 206         volatile u32 tx_current;
 207         u32 rx_current;
 208         u32 iqtx_current;
 209         u32 iqrx_current;
 210
 211         volatile u32 tx_dirty;
 212         volatile u32 ltda;
 213         u32 rx_dirty;
 214         u32 lrda;
 215
 216         dma_addr_t tx_fd_dma;
 217         dma_addr_t rx_fd_dma;
 218         dma_addr_t iqtx_dma;
 219         dma_addr_t iqrx_dma;
 220
 221         u32 scc_regs[SCC_REGISTERS_MAX]; /* Cf errata DS5 p.4 */
 222
 223         struct timer_list timer;
 224
 225         struct dscc4_pci_priv *pci_priv;
 226         spinlock_t lock;
 227
 228         int dev_id;
 229         volatile u32 flags;
 230         u32 timer_help;
 231
 232         unsigned short encoding;
 233         unsigned short parity;
 234         struct net_device *dev;
 235         sync_serial_settings settings;
 236         void __iomem *base_addr;
 237         u32 __pad __attribute__ ((aligned (4)));
 238 };
 239
 240 /* GLOBAL registers definitions */
 241 #define GCMDR   0x00
 242 #define GSTAR   0x04
 243 #define GMODE   0x08
 244 #define IQLENR0 0x0C
 245 #define IQLENR1 0x10
 246 #define IQRX0   0x14
 247 #define IQTX0   0x24
 248 #define IQCFG   0x3c
 249 #define FIFOCR1 0x44
 250 #define FIFOCR2 0x48
 251 #define FIFOCR3 0x4c
 252 #define FIFOCR4 0x34
 253 #define CH0CFG  0x50
 254 #define CH0BRDA 0x54
 255 #define CH0BTDA 0x58
 256 #define CH0FRDA 0x98
 257 #define CH0FTDA 0xb0
 258 #define CH0LRDA 0xc8
 259 #define CH0LTDA 0xe0
 260
 261 /* SCC registers definitions */
 262 #define SCC_START       0x0100
 263 #define SCC_OFFSET      0x80
 264 #define CMDR    0x00
 265 #define STAR    0x04
 266 #define CCR0    0x08
 267 #define CCR1    0x0c
 268 #define CCR2    0x10
 269 #define BRR     0x2C
 270 #define RLCR    0x40
 271 #define IMR     0x54
 272 #define ISR     0x58
 273
 274 #define GPDIR   0x0400
 275 #define GPDATA  0x0404
 276 #define GPIM    0x0408
 277
 278 /* Bit masks */
 279 #define EncodingMask    0x00700000
 280 #define CrcMask         0x00000003
 281
 282 #define IntRxScc0       0x10000000
 283 #define IntTxScc0       0x01000000
 284
 285 #define TxPollCmd       0x00000400
 286 #define RxActivate      0x08000000
 287 #define MTFi            0x04000000
 288 #define Rdr             0x00400000
 289 #define Rdt             0x00200000
 290 #define Idr             0x00100000
 291 #define Idt             0x00080000
 292 #define TxSccRes        0x01000000
 293 #define RxSccRes        0x00010000
 294 #define TxSizeMax       0x1fff          /* Datasheet DS1 - 11.1.1.1 */
 295 #define RxSizeMax       0x1ffc          /* Datasheet DS1 - 11.1.2.1 */
 296
 297 #define Ccr0ClockMask   0x0000003f
 298 #define Ccr1LoopMask    0x00000200
 299 #define IsrMask         0x000fffff
 300 #define BrrExpMask      0x00000f00
 301 #define BrrMultMask     0x0000003f
 302 #define EncodingMask    0x00700000
 303 #define Hold            cpu_to_le32(0x40000000)
 304 #define SccBusy         0x10000000
 305 #define PowerUp         0x80000000
 306 #define Vis             0x00001000
 307 #define FrameOk         (FrameVfr | FrameCrc)
 308 #define FrameVfr        0x80
 309 #define FrameRdo        0x40
 310 #define FrameCrc        0x20
 311 #define FrameRab        0x10
 312 #define FrameAborted    cpu_to_le32(0x00000200)
 313 #define FrameEnd        cpu_to_le32(0x80000000)
 314 #define DataComplete    cpu_to_le32(0x40000000)
 315 #define LengthCheck     0x00008000
 316 #define SccEvt          0x02000000
 317 #define NoAck           0x00000200
 318 #define Action          0x00000001
 319 #define HiDesc          cpu_to_le32(0x20000000)
 320
 321 /* SCC events */
 322 #define RxEvt           0xf0000000
 323 #define TxEvt           0x0f000000
 324 #define Alls            0x00040000
 325 #define Xdu             0x00010000
 326 #define Cts             0x00004000
 327 #define Xmr             0x00002000
 328 #define Xpr             0x00001000
 329 #define Rdo             0x00000080
 330 #define Rfs             0x00000040
 331 #define Cd              0x00000004
 332 #define Rfo             0x00000002
 333 #define Flex            0x00000001
 334
 335 /* DMA core events */
 336 #define Cfg             0x00200000
 337 #define Hi              0x00040000
 338 #define Fi              0x00020000
 339 #define Err             0x00010000
 340 #define Arf             0x00000002
 341 #define ArAck           0x00000001
 342
 343 /* State flags */
 344 #define Ready           0x00000000
 345 #define NeedIDR         0x00000001
 346 #define NeedIDT         0x00000002
 347 #define RdoSet          0x00000004
 348 #define FakeReset       0x00000008
 349
 350 /* Don't mask RDO. Ever. */
 351 #ifdef DSCC4_POLLING
 352 #define EventsMask      0xfffeef7f
 353 #else
 354 #define EventsMask      0xfffa8f7a
 355 #endif
 356
 357 /* Functions prototypes */
 358 static void dscc4_rx_irq(struct dscc4_pci_priv *, struct dscc4_dev_priv *);
 359 static void dscc4_tx_irq(struct dscc4_pci_priv *, struct dscc4_dev_priv *);
 360 static int dscc4_found1(struct pci_dev *, void __iomem *ioaddr);
 361 static int dscc4_init_one(struct pci_dev *, const struct pci_device_id *ent);
 362 static int dscc4_open(struct net_device *);
 363 static netdev_tx_t dscc4_start_xmit(struct sk_buff *,
 364                                           struct net_device *);
 365 static int dscc4_close(struct net_device *);
 366 static int dscc4_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
 367 static int dscc4_init_ring(struct net_device *);
 368 static void dscc4_release_ring(struct dscc4_dev_priv *);
 369 static void dscc4_timer(unsigned long);
 370 static void dscc4_tx_timeout(struct net_device *);
 371 static irqreturn_t dscc4_irq(int irq, void *dev_id);
 372 static int dscc4_hdlc_attach(struct net_device *, unsigned short, unsigned short);
 373 static int dscc4_set_iface(struct dscc4_dev_priv *, struct net_device *);
 374 #ifdef DSCC4_POLLING
 375 static int dscc4_tx_poll(struct dscc4_dev_priv *, struct net_device *);
 376 #endif
 377
 378 static inline struct dscc4_dev_priv *dscc4_priv(struct net_device *dev)
 379 {
 380         return dev_to_hdlc(dev)->priv;
 381 }
 382
 383 static inline struct net_device *dscc4_to_dev(struct dscc4_dev_priv *p)
 384 {
 385         return p->dev;
 386 }
 387
 388 static void scc_patchl(u32 mask, u32 value, struct dscc4_dev_priv *dpriv,
 389                         struct net_device *dev, int offset)
 390 {
 391         u32 state;
 392
 393         /* Cf scc_writel for concern regarding thread-safety */
 394         state = dpriv->scc_regs[offset >> 2];
 395         state &= ~mask;
 396         state |= value;
 397         dpriv->scc_regs[offset >> 2] = state;
 398         writel(state, dpriv->base_addr + SCC_REG_START(dpriv) + offset);
 399 }
 400
 401 static void scc_writel(u32 bits, struct dscc4_dev_priv *dpriv,
 402                        struct net_device *dev, int offset)
 403 {
 404         /*
 405          * Thread-UNsafe.
 406          * As of 2002/02/16, there are no thread racing for access.
 407          */
 408         dpriv->scc_regs[offset >> 2] = bits;
 409         writel(bits, dpriv->base_addr + SCC_REG_START(dpriv) + offset);
 410 }
 411
 412 static inline u32 scc_readl(struct dscc4_dev_priv *dpriv, int offset)
 413 {
 414         return dpriv->scc_regs[offset >> 2];
 415 }
 416
 417 static u32 scc_readl_star(struct dscc4_dev_priv *dpriv, struct net_device *dev)
 418 {
 419         /* Cf errata DS5 p.4 */
 420         readl(dpriv->base_addr + SCC_REG_START(dpriv) + STAR);
 421         return readl(dpriv->base_addr + SCC_REG_START(dpriv) + STAR);
 422 }
 423
 424 static inline void dscc4_do_tx(struct dscc4_dev_priv *dpriv,
 425                                struct net_device *dev)
 426 {
 427         dpriv->ltda = dpriv->tx_fd_dma +
 428                       ((dpriv->tx_current-1)%TX_RING_SIZE)*sizeof(struct TxFD);
 429         writel(dpriv->ltda, dpriv->base_addr + CH0LTDA + dpriv->dev_id*4);
 430         /* Flush posted writes *NOW* */
 431         readl(dpriv->base_addr + CH0LTDA + dpriv->dev_id*4);
 432 }
 433
 434 static inline void dscc4_rx_update(struct dscc4_dev_priv *dpriv,
 435                                    struct net_device *dev)
 436 {
 437         dpriv->lrda = dpriv->rx_fd_dma +
 438                       ((dpriv->rx_dirty - 1)%RX_RING_SIZE)*sizeof(struct RxFD);
 439         writel(dpriv->lrda, dpriv->base_addr + CH0LRDA + dpriv->dev_id*4);
 440 }
 441
 442 static inline unsigned int dscc4_tx_done(struct dscc4_dev_priv *dpriv)
 443 {
 444         return dpriv->tx_current == dpriv->tx_dirty;
 445 }
 446
 447 static inline unsigned int dscc4_tx_quiescent(struct dscc4_dev_priv *dpriv,
 448                                               struct net_device *dev)
 449 {
 450         return readl(dpriv->base_addr + CH0FTDA + dpriv->dev_id*4) == dpriv->ltda;
 451 }
 452
 453 static int state_check(u32 state, struct dscc4_dev_priv *dpriv,
 454                        struct net_device *dev, const char *msg)
 455 {
 456         int ret = 0;
 457
 458         if (debug > 1) {
 459         if (SOURCE_ID(state) != dpriv->dev_id) {
 460                 printk(KERN_DEBUG "%s (%s): Source Id=%d, state=%08x\n",
 461                        dev->name, msg, SOURCE_ID(state), state );
 462                         ret = -1;
 463         }
 464         if (state & 0x0df80c00) {
 465                 printk(KERN_DEBUG "%s (%s): state=%08x (UFO alert)\n",
 466                        dev->name, msg, state);
 467                         ret = -1;
 468         }
 469         }
 470         return ret;
 471 }
 472
 473 static void dscc4_tx_print(struct net_device *dev,
 474                            struct dscc4_dev_priv *dpriv,
 475                            char *msg)
 476 {
 477         printk(KERN_DEBUG "%s: tx_current=%02d tx_dirty=%02d (%s)\n",
 478                dev->name, dpriv->tx_current, dpriv->tx_dirty, msg);
 479 }
 480
 481 static void dscc4_release_ring(struct dscc4_dev_priv *dpriv)
 482 {
 483         struct pci_dev *pdev = dpriv->pci_priv->pdev;
 484         struct TxFD *tx_fd = dpriv->tx_fd;
 485         struct RxFD *rx_fd = dpriv->rx_fd;
 486         struct sk_buff **skbuff;
 487         int i;
 488
 489         pci_free_consistent(pdev, TX_TOTAL_SIZE, tx_fd, dpriv->tx_fd_dma);
 490         pci_free_consistent(pdev, RX_TOTAL_SIZE, rx_fd, dpriv->rx_fd_dma);
 491
 492         skbuff = dpriv->tx_skbuff;
 493         for (i = 0; i < TX_RING_SIZE; i++) {
 494                 if (*skbuff) {
 495                         pci_unmap_single(pdev, le32_to_cpu(tx_fd->data),
 496                                 (*skbuff)->len, PCI_DMA_TODEVICE);
 497                         dev_kfree_skb(*skbuff);
 498                 }
 499                 skbuff++;
 500                 tx_fd++;
 501         }
 502
 503         skbuff = dpriv->rx_skbuff;
 504         for (i = 0; i < RX_RING_SIZE; i++) {
 505                 if (*skbuff) {
 506                         pci_unmap_single(pdev, le32_to_cpu(rx_fd->data),
 507                                 RX_MAX(HDLC_MAX_MRU), PCI_DMA_FROMDEVICE);
 508                         dev_kfree_skb(*skbuff);
 509                 }
 510                 skbuff++;
 511                 rx_fd++;
 512         }
 513 }
 514
 515 static inline int try_get_rx_skb(struct dscc4_dev_priv *dpriv,
 516                                  struct net_device *dev)
 517 {
 518         unsigned int dirty = dpriv->rx_dirty%RX_RING_SIZE;
 519         struct RxFD *rx_fd = dpriv->rx_fd + dirty;
 520         const int len = RX_MAX(HDLC_MAX_MRU);
 521         struct sk_buff *skb;
 522         int ret = 0;
 523
 524         skb = dev_alloc_skb(len);
 525         dpriv->rx_skbuff[dirty] = skb;
 526         if (skb) {
 527                 skb->protocol = hdlc_type_trans(skb, dev);
 528                 rx_fd->data = cpu_to_le32(pci_map_single(dpriv->pci_priv->pdev,
 529                                           skb->data, len, PCI_DMA_FROMDEVICE));
 530         } else {
 531                 rx_fd->data = 0;
 532                 ret = -1;
 533         }
 534         return ret;
 535 }
 536
 537 /*
 538  * IRQ/thread/whatever safe
 539  */
 540 static int dscc4_wait_ack_cec(struct dscc4_dev_priv *dpriv,
 541                               struct net_device *dev, char *msg)
 542 {
 543         s8 i = 0;
 544
 545         do {
 546                 if (!(scc_readl_star(dpriv, dev) & SccBusy)) {
 547                         printk(KERN_DEBUG "%s: %s ack (%d try)\n", dev->name,
 548                                msg, i);
 549                         goto done;
 550                 }
 551                 schedule_timeout_uninterruptible(10);
 552                 rmb();
 553         } while (++i > 0);
 554         printk(KERN_ERR "%s: %s timeout\n", dev->name, msg);
 555 done:
 556         return (i >= 0) ? i : -EAGAIN;
 557 }
 558
 559 static int dscc4_do_action(struct net_device *dev, char *msg)
 560 {
 561         void __iomem *ioaddr = dscc4_priv(dev)->base_addr;
 562         s16 i = 0;
 563
 564         writel(Action, ioaddr + GCMDR);
 565         ioaddr += GSTAR;
 566         do {
 567                 u32 state = readl(ioaddr);
 568
 569                 if (state & ArAck) {
 570                         printk(KERN_DEBUG "%s: %s ack\n", dev->name, msg);
 571                         writel(ArAck, ioaddr);
 572                         goto done;
 573                 } else if (state & Arf) {
 574                         printk(KERN_ERR "%s: %s failed\n", dev->name, msg);
 575                         writel(Arf, ioaddr);
 576                         i = -1;
 577                         goto done;
 578         }
 579                 rmb();
 580         } while (++i > 0);
 581         printk(KERN_ERR "%s: %s timeout\n", dev->name, msg);
 582 done:
 583         return i;
 584 }
 585
 586 static inline int dscc4_xpr_ack(struct dscc4_dev_priv *dpriv)
 587 {
 588         int cur = dpriv->iqtx_current%IRQ_RING_SIZE;
 589         s8 i = 0;
 590
 591         do {
 592                 if (!(dpriv->flags & (NeedIDR | NeedIDT)) ||
 593                     (dpriv->iqtx[cur] & cpu_to_le32(Xpr)))
 594                         break;
 595                 smp_rmb();
 596                 schedule_timeout_uninterruptible(10);
 597         } while (++i > 0);
 598
 599         return (i >= 0 ) ? i : -EAGAIN;
 600 }
 601
 602 #if 0 /* dscc4_{rx/tx}_reset are both unreliable - more tweak needed */
 603 static void dscc4_rx_reset(struct dscc4_dev_priv *dpriv, struct net_device *dev)
 604 {
 605         unsigned long flags;
 606
 607         spin_lock_irqsave(&dpriv->pci_priv->lock, flags);
 608         /* Cf errata DS5 p.6 */
 609         writel(0x00000000, dpriv->base_addr + CH0LRDA + dpriv->dev_id*4);
 610         scc_patchl(PowerUp, 0, dpriv, dev, CCR0);
 611         readl(dpriv->base_addr + CH0LRDA + dpriv->dev_id*4);
 612         writel(MTFi|Rdr, dpriv->base_addr + dpriv->dev_id*0x0c + CH0CFG);
 613         writel(Action, dpriv->base_addr + GCMDR);
 614         spin_unlock_irqrestore(&dpriv->pci_priv->lock, flags);
 615 }
 616
 617 #endif
 618
 619 #if 0
 620 static void dscc4_tx_reset(struct dscc4_dev_priv *dpriv, struct net_device *dev)
 621 {
 622         u16 i = 0;
 623
 624         /* Cf errata DS5 p.7 */
 625         scc_patchl(PowerUp, 0, dpriv, dev, CCR0);
 626         scc_writel(0x00050000, dpriv, dev, CCR2);
 627         /*
 628          * Must be longer than the time required to fill the fifo.
 629          */
 630         while (!dscc4_tx_quiescent(dpriv, dev) && ++i) {
 631                 udelay(1);
 632                 wmb();
 633         }
 634
 635         writel(MTFi|Rdt, dpriv->base_addr + dpriv->dev_id*0x0c + CH0CFG);
 636         if (dscc4_do_action(dev, "Rdt") < 0)
 637                 printk(KERN_ERR "%s: Tx reset failed\n", dev->name);
 638 }
 639 #endif
 640
 641 /* TODO: (ab)use this function to refill a completely depleted RX ring. */
 642 static inline void dscc4_rx_skb(struct dscc4_dev_priv *dpriv,
 643                                 struct net_device *dev)
 644 {
 645         struct RxFD *rx_fd = dpriv->rx_fd + dpriv->rx_current%RX_RING_SIZE;
 646         struct pci_dev *pdev = dpriv->pci_priv->pdev;
 647         struct sk_buff *skb;
 648         int pkt_len;
 649
 650         skb = dpriv->rx_skbuff[dpriv->rx_current++%RX_RING_SIZE];
 651         if (!skb) {
 652                 printk(KERN_DEBUG "%s: skb=0 (%s)\n", dev->name, __func__);
 653                 goto refill;
 654         }
 655         pkt_len = TO_SIZE(le32_to_cpu(rx_fd->state2));
 656         pci_unmap_single(pdev, le32_to_cpu(rx_fd->data),
 657                          RX_MAX(HDLC_MAX_MRU), PCI_DMA_FROMDEVICE);
 658         if ((skb->data[--pkt_len] & FrameOk) == FrameOk) {
 659                 dev->stats.rx_packets++;
 660                 dev->stats.rx_bytes += pkt_len;
 661                 skb_put(skb, pkt_len);
 662                 if (netif_running(dev))
 663                         skb->protocol = hdlc_type_trans(skb, dev);
 664                 netif_rx(skb);
 665         } else {
 666                 if (skb->data[pkt_len] & FrameRdo)
 667                         dev->stats.rx_fifo_errors++;
 668                 else if (!(skb->data[pkt_len] & FrameCrc))
 669                         dev->stats.rx_crc_errors++;
 670                 else if ((skb->data[pkt_len] & (FrameVfr | FrameRab)) !=
 671                          (FrameVfr | FrameRab))
 672                         dev->stats.rx_length_errors++;
 673                 dev->stats.rx_errors++;
 674                 dev_kfree_skb_irq(skb);
 675         }
 676 refill:
 677         while ((dpriv->rx_dirty - dpriv->rx_current) % RX_RING_SIZE) {
 678                 if (try_get_rx_skb(dpriv, dev) < 0)
 679                         break;
 680                 dpriv->rx_dirty++;
 681         }
 682         dscc4_rx_update(dpriv, dev);
 683         rx_fd->state2 = 0x00000000;
 684         rx_fd->end = cpu_to_le32(0xbabeface);
 685 }
 686
 687 static void dscc4_free1(struct pci_dev *pdev)
 688 {
 689         struct dscc4_pci_priv *ppriv;
 690         struct dscc4_dev_priv *root;
 691         int i;
 692
 693         ppriv = pci_get_drvdata(pdev);
 694         root = ppriv->root;
 695
 696         for (i = 0; i < dev_per_card; i++)
 697                 unregister_hdlc_device(dscc4_to_dev(root + i));
 698
 699         pci_set_drvdata(pdev, NULL);
 700
 701         for (i = 0; i < dev_per_card; i++)
 702                 free_netdev(root[i].dev);
 703         kfree(root);
 704         kfree(ppriv);
 705 }
 706
 707 static int __devinit dscc4_init_one(struct pci_dev *pdev,
 708                                   const struct pci_device_id *ent)
 709 {
 710         struct dscc4_pci_priv *priv;
 711         struct dscc4_dev_priv *dpriv;
 712         void __iomem *ioaddr;
 713         int i, rc;
 714
 715         printk(KERN_DEBUG "%s", version);
 716
 717         rc = pci_enable_device(pdev);
 718         if (rc < 0)
 719                 goto out;
 720
 721         rc = pci_request_region(pdev, 0, "registers");
 722         if (rc < 0) {
 723                 printk(KERN_ERR "%s: can't reserve MMIO region (regs)\n",
 724                         DRV_NAME);
 725                 goto err_disable_0;
 726         }
 727         rc = pci_request_region(pdev, 1, "LBI interface");
 728         if (rc < 0) {
 729                 printk(KERN_ERR "%s: can't reserve MMIO region (lbi)\n",
 730                         DRV_NAME);
 731                 goto err_free_mmio_region_1;
 732         }
 733
 734         ioaddr = pci_ioremap_bar(pdev, 0);
 735         if (!ioaddr) {
 736                 printk(KERN_ERR "%s: cannot remap MMIO region %llx @ %llx\n",
 737                         DRV_NAME, (unsigned long long)pci_resource_len(pdev, 0),
 738                         (unsigned long long)pci_resource_start(pdev, 0));
 739                 rc = -EIO;
 740                 goto err_free_mmio_regions_2;
 741         }
 742         printk(KERN_DEBUG "Siemens DSCC4, MMIO at %#llx (regs), %#llx (lbi), IRQ %d\n",
 743                 (unsigned long long)pci_resource_start(pdev, 0),
 744                 (unsigned long long)pci_resource_start(pdev, 1), pdev->irq);
 745
 746         /* Cf errata DS5 p.2 */
 747         pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 0xf8);
 748         pci_set_master(pdev);
 749
 750         rc = dscc4_found1(pdev, ioaddr);
 751         if (rc < 0)
 752                 goto err_iounmap_3;
 753
 754         priv = pci_get_drvdata(pdev);
 755
 756         rc = request_irq(pdev->irq, dscc4_irq, IRQF_SHARED, DRV_NAME, priv->root);
 757         if (rc < 0) {
 758                 printk(KERN_WARNING "%s: IRQ %d busy\n", DRV_NAME, pdev->irq);
 759                 goto err_release_4;
 760         }
 761
 762         /* power up/little endian/dma core controlled via lrda/ltda */
 763         writel(0x00000001, ioaddr + GMODE);
 764         /* Shared interrupt queue */
 765         {
 766                 u32 bits;
 767
 768                 bits = (IRQ_RING_SIZE >> 5) - 1;
 769                 bits |= bits << 4;
 770                 bits |= bits << 8;
 771                 bits |= bits << 16;
 772                 writel(bits, ioaddr + IQLENR0);
 773         }
 774         /* Global interrupt queue */
 775         writel((u32)(((IRQ_RING_SIZE >> 5) - 1) << 20), ioaddr + IQLENR1);
 776         priv->iqcfg = (__le32 *) pci_alloc_consistent(pdev,
 777                 IRQ_RING_SIZE*sizeof(__le32), &priv->iqcfg_dma);
 778         if (!priv->iqcfg)
 779                 goto err_free_irq_5;
 780         writel(priv->iqcfg_dma, ioaddr + IQCFG);
 781
 782         rc = -ENOMEM;
 783
 784         /*
 785          * SCC 0-3 private rx/tx irq structures
 786          * IQRX/TXi needs to be set soon. Learned it the hard way...
 787          */
 788         for (i = 0; i < dev_per_card; i++) {
 789                 dpriv = priv->root + i;
 790                 dpriv->iqtx = (__le32 *) pci_alloc_consistent(pdev,
 791                         IRQ_RING_SIZE*sizeof(u32), &dpriv->iqtx_dma);
 792                 if (!dpriv->iqtx)
 793                         goto err_free_iqtx_6;
 794                 writel(dpriv->iqtx_dma, ioaddr + IQTX0 + i*4);
 795         }
 796         for (i = 0; i < dev_per_card; i++) {
 797                 dpriv = priv->root + i;
 798                 dpriv->iqrx = (__le32 *) pci_alloc_consistent(pdev,
 799                         IRQ_RING_SIZE*sizeof(u32), &dpriv->iqrx_dma);
 800                 if (!dpriv->iqrx)
 801                         goto err_free_iqrx_7;
 802                 writel(dpriv->iqrx_dma, ioaddr + IQRX0 + i*4);
 803         }
 804
 805         /* Cf application hint. Beware of hard-lock condition on threshold. */
 806         writel(0x42104000, ioaddr + FIFOCR1);
 807         //writel(0x9ce69800, ioaddr + FIFOCR2);
 808         writel(0xdef6d800, ioaddr + FIFOCR2);
 809         //writel(0x11111111, ioaddr + FIFOCR4);
 810         writel(0x18181818, ioaddr + FIFOCR4);
 811         // FIXME: should depend on the chipset revision
 812         writel(0x0000000e, ioaddr + FIFOCR3);
 813
 814         writel(0xff200001, ioaddr + GCMDR);
 815
 816         rc = 0;
 817 out:
 818         return rc;
 819
 820 err_free_iqrx_7:
 821         while (--i >= 0) {
 822                 dpriv = priv->root + i;
 823                 pci_free_consistent(pdev, IRQ_RING_SIZE*sizeof(u32),
 824                                     dpriv->iqrx, dpriv->iqrx_dma);
 825         }
 826         i = dev_per_card;
 827 err_free_iqtx_6:
 828         while (--i >= 0) {
 829                 dpriv = priv->root + i;
 830                 pci_free_consistent(pdev, IRQ_RING_SIZE*sizeof(u32),
 831                                     dpriv->iqtx, dpriv->iqtx_dma);
 832         }
 833         pci_free_consistent(pdev, IRQ_RING_SIZE*sizeof(u32), priv->iqcfg,
 834                             priv->iqcfg_dma);
 835 err_free_irq_5:
 836         free_irq(pdev->irq, priv->root);
 837 err_release_4:
 838         dscc4_free1(pdev);
 839 err_iounmap_3:
 840         iounmap (ioaddr);
 841 err_free_mmio_regions_2:
 842         pci_release_region(pdev, 1);
 843 err_free_mmio_region_1:
 844         pci_release_region(pdev, 0);
 845 err_disable_0:
 846         pci_disable_device(pdev);
 847         goto out;
 848 };
 849
 850 /*
 851  * Let's hope the default values are decent enough to protect my
 852  * feet from the user's gun - Ueimor
 853  */
 854 static void dscc4_init_registers(struct dscc4_dev_priv *dpriv,
 855                                  struct net_device *dev)
 856 {
 857         /* No interrupts, SCC core disabled. Let's relax */
 858         scc_writel(0x00000000, dpriv, dev, CCR0);
 859
 860         scc_writel(LengthCheck | (HDLC_MAX_MRU >> 5), dpriv, dev, RLCR);
 861
 862         /*
 863          * No address recognition/crc-CCITT/cts enabled
 864          * Shared flags transmission disabled - cf errata DS5 p.11
 865          * Carrier detect disabled - cf errata p.14
 866          * FIXME: carrier detection/polarity may be handled more gracefully.
 867          */
 868         scc_writel(0x02408000, dpriv, dev, CCR1);
 869
 870         /* crc not forwarded - Cf errata DS5 p.11 */
 871         scc_writel(0x00050008 & ~RxActivate, dpriv, dev, CCR2);
 872         // crc forwarded
 873         //scc_writel(0x00250008 & ~RxActivate, dpriv, dev, CCR2);
 874 }
 875
 876 static inline int dscc4_set_quartz(struct dscc4_dev_priv *dpriv, int hz)
 877 {
 878         int ret = 0;
 879
 880         if ((hz < 0) || (hz > DSCC4_HZ_MAX))
 881                 ret = -EOPNOTSUPP;
 882         else
 883                 dpriv->pci_priv->xtal_hz = hz;
 884
 885         return ret;
 886 }
 887
 888 static const struct net_device_ops dscc4_ops = {
 889         .ndo_open       = dscc4_open,
 890         .ndo_stop       = dscc4_close,
 891         .ndo_change_mtu = hdlc_change_mtu,
 892         .ndo_start_xmit = hdlc_start_xmit,
 893         .ndo_do_ioctl   = dscc4_ioctl,
 894         .ndo_tx_timeout = dscc4_tx_timeout,
 895 };
 896
 897 static int dscc4_found1(struct pci_dev *pdev, void __iomem *ioaddr)
 898 {
 899         struct dscc4_pci_priv *ppriv;
 900         struct dscc4_dev_priv *root;
 901         int i, ret = -ENOMEM;
 902
 903         root = kcalloc(dev_per_card, sizeof(*root), GFP_KERNEL);
 904         if (!root) {
 905                 printk(KERN_ERR "%s: can't allocate data\n", DRV_NAME);
 906                 goto err_out;
 907         }
 908
 909         for (i = 0; i < dev_per_card; i++) {
 910                 root[i].dev = alloc_hdlcdev(root + i);
 911                 if (!root[i].dev)
 912                         goto err_free_dev;
 913         }
 914
 915         ppriv = kzalloc(sizeof(*ppriv), GFP_KERNEL);
 916         if (!ppriv) {
 917                 printk(KERN_ERR "%s: can't allocate private data\n", DRV_NAME);
 918                 goto err_free_dev;
 919         }
 920
 921         ppriv->root = root;
 922         spin_lock_init(&ppriv->lock);
 923
 924         for (i = 0; i < dev_per_card; i++) {
 925                 struct dscc4_dev_priv *dpriv = root + i;
 926                 struct net_device *d = dscc4_to_dev(dpriv);
 927                 hdlc_device *hdlc = dev_to_hdlc(d);
 928
 929                 d->base_addr = (unsigned long)ioaddr;
 930                 d->irq = pdev->irq;
 931                 d->netdev_ops = &dscc4_ops;
 932                 d->watchdog_timeo = TX_TIMEOUT;
 933                 SET_NETDEV_DEV(d, &pdev->dev);
 934
 935                 dpriv->dev_id = i;
 936                 dpriv->pci_priv = ppriv;
 937                 dpriv->base_addr = ioaddr;
 938                 spin_lock_init(&dpriv->lock);
 939
 940                 hdlc->xmit = dscc4_start_xmit;
 941                 hdlc->attach = dscc4_hdlc_attach;
 942
 943                 dscc4_init_registers(dpriv, d);
 944                 dpriv->parity = PARITY_CRC16_PR0_CCITT;
 945                 dpriv->encoding = ENCODING_NRZ;
 946
 947                 ret = dscc4_init_ring(d);
 948                 if (ret < 0)
 949                         goto err_unregister;
 950
 951                 ret = register_hdlc_device(d);
 952                 if (ret < 0) {
 953                         printk(KERN_ERR "%s: unable to register\n", DRV_NAME);
 954                         dscc4_release_ring(dpriv);
 955                         goto err_unregister;
 956                 }
 957         }
 958
 959         ret = dscc4_set_quartz(root, quartz);
 960         if (ret < 0)
 961                 goto err_unregister;
 962
 963         pci_set_drvdata(pdev, ppriv);
 964         return ret;
 965
 966 err_unregister:
 967         while (i-- > 0) {
 968                 dscc4_release_ring(root + i);
 969                 unregister_hdlc_device(dscc4_to_dev(root + i));
 970         }
 971         kfree(ppriv);
 972         i = dev_per_card;
 973 err_free_dev:
 974         while (i-- > 0)
 975                 free_netdev(root[i].dev);
 976         kfree(root);
 977 err_out:
 978         return ret;
 979 };
 980
 981 /* FIXME: get rid of the unneeded code */
 982 static void dscc4_timer(unsigned long data)
 983 {
 984         struct net_device *dev = (struct net_device *)data;
 985         struct dscc4_dev_priv *dpriv = dscc4_priv(dev);
 986 //      struct dscc4_pci_priv *ppriv;
 987
 988         goto done;
 989 done:
 990         dpriv->timer.expires = jiffies + TX_TIMEOUT;
 991         add_timer(&dpriv->timer);
 992 }
 993
 994 static void dscc4_tx_timeout(struct net_device *dev)
 995 {
 996         /* FIXME: something is missing there */
 997 }
 998
 999 static int dscc4_loopback_check(struct dscc4_dev_priv *dpriv)
1000 {
1001         sync_serial_settings *settings = &dpriv->settings;
1002
1003         if (settings->loopback && (settings->clock_type != CLOCK_INT)) {
1004                 struct net_device *dev = dscc4_to_dev(dpriv);
1005
1006                 printk(KERN_INFO "%s: loopback requires clock\n", dev->name);
1007                 return -1;
1008         }
1009         return 0;
1010 }
1011
1012 #ifdef CONFIG_DSCC4_PCI_RST
1013 /*
1014  * Some DSCC4-based cards wires the GPIO port and the PCI #RST pin together
1015  * so as to provide a safe way to reset the asic while not the whole machine
1016  * rebooting.
1017  *
1018  * This code doesn't need to be efficient. Keep It Simple
1019  */
1020 static void dscc4_pci_reset(struct pci_dev *pdev, void __iomem *ioaddr)
1021 {
1022         int i;
1023
1024         mutex_lock(&dscc4_mutex);
1025         for (i = 0; i < 16; i++)
1026                 pci_read_config_dword(pdev, i << 2, dscc4_pci_config_store + i);
1027
1028         /* Maximal LBI clock divider (who cares ?) and whole GPIO range. */
1029         writel(0x001c0000, ioaddr + GMODE);
1030         /* Configure GPIO port as output */
1031         writel(0x0000ffff, ioaddr + GPDIR);
1032         /* Disable interruption */
1033         writel(0x0000ffff, ioaddr + GPIM);
1034
1035         writel(0x0000ffff, ioaddr + GPDATA);
1036         writel(0x00000000, ioaddr + GPDATA);
1037
1038         /* Flush posted writes */
1039         readl(ioaddr + GSTAR);
1040
1041         schedule_timeout_uninterruptible(10);
1042
1043         for (i = 0; i < 16; i++)
1044                 pci_write_config_dword(pdev, i << 2, dscc4_pci_config_store[i]);
1045         mutex_unlock(&dscc4_mutex);
1046 }
1047 #else
1048 #define dscc4_pci_reset(pdev,ioaddr)    do {} while (0)
1049 #endif /* CONFIG_DSCC4_PCI_RST */
1050
1051 static int dscc4_open(struct net_device *dev)
1052 {
1053         struct dscc4_dev_priv *dpriv = dscc4_priv(dev);
1054         struct dscc4_pci_priv *ppriv;
1055         int ret = -EAGAIN;
1056
1057         if ((dscc4_loopback_check(dpriv) < 0))
1058                 goto err;
1059
1060         if ((ret = hdlc_open(dev)))
1061                 goto err;
1062
1063         ppriv = dpriv->pci_priv;
1064
1065         /*
1066          * Due to various bugs, there is no way to reliably reset a
1067          * specific port (manufacturer's dependant special PCI #RST wiring
1068          * apart: it affects all ports). Thus the device goes in the best
1069          * silent mode possible at dscc4_close() time and simply claims to
1070          * be up if it's opened again. It still isn't possible to change
1071          * the HDLC configuration without rebooting but at least the ports
1072          * can be up/down ifconfig'ed without killing the host.
1073          */
1074         if (dpriv->flags & FakeReset) {
1075                 dpriv->flags &= ~FakeReset;
1076                 scc_patchl(0, PowerUp, dpriv, dev, CCR0);
1077                 scc_patchl(0, 0x00050000, dpriv, dev, CCR2);
1078                 scc_writel(EventsMask, dpriv, dev, IMR);
1079                 printk(KERN_INFO "%s: up again.\n", dev->name);
1080                 goto done;
1081         }
1082
1083         /* IDT+IDR during XPR */
1084         dpriv->flags = NeedIDR | NeedIDT;
1085
1086         scc_patchl(0, PowerUp | Vis, dpriv, dev, CCR0);
1087
1088         /*
1089          * The following is a bit paranoid...
1090          *
1091          * NB: the datasheet "...CEC will stay active if the SCC is in
1092          * power-down mode or..." and CCR2.RAC = 1 are two different
1093          * situations.
1094          */
1095         if (scc_readl_star(dpriv, dev) & SccBusy) {
1096                 printk(KERN_ERR "%s busy. Try later\n", dev->name);
1097                 ret = -EAGAIN;
1098                 goto err_out;
1099         } else
1100                 printk(KERN_INFO "%s: available. Good\n", dev->name);
1101
1102         scc_writel(EventsMask, dpriv, dev, IMR);
1103
1104         /* Posted write is flushed in the wait_ack loop */
1105         scc_writel(TxSccRes | RxSccRes, dpriv, dev, CMDR);
1106
1107         if ((ret = dscc4_wait_ack_cec(dpriv, dev, "Cec")) < 0)
1108                 goto err_disable_scc_events;
1109
1110         /*
1111          * I would expect XPR near CE completion (before ? after ?).
1112          * At worst, this code won't see a late XPR and people
1113          * will have to re-issue an ifconfig (this is harmless).
1114          * WARNING, a really missing XPR usually means a hardware
1115          * reset is needed. Suggestions anyone ?
1116          */
1117         if ((ret = dscc4_xpr_ack(dpriv)) < 0) {
1118                 printk(KERN_ERR "%s: %s timeout\n", DRV_NAME, "XPR");
1119                 goto err_disable_scc_events;
1120         }
1121
1122         if (debug > 2)
1123                 dscc4_tx_print(dev, dpriv, "Open");
1124
1125 done:
1126         netif_start_queue(dev);
1127
1128         init_timer(&dpriv->timer);
1129         dpriv->timer.expires = jiffies + 10*HZ;
1130         dpriv->timer.data = (unsigned long)dev;
1131         dpriv->timer.function = dscc4_timer;
1132         add_timer(&dpriv->timer);
1133         netif_carrier_on(dev);
1134
1135         return 0;
1136
1137 err_disable_scc_events:
1138         scc_writel(0xffffffff, dpriv, dev, IMR);
1139         scc_patchl(PowerUp | Vis, 0, dpriv, dev, CCR0);
1140 err_out:
1141         hdlc_close(dev);
1142 err:
1143         return ret;
1144 }
1145
1146 #ifdef DSCC4_POLLING
1147 static int dscc4_tx_poll(struct dscc4_dev_priv *dpriv, struct net_device *dev)
1148 {
1149         /* FIXME: it's gonna be easy (TM), for sure */
1150 }
1151 #endif /* DSCC4_POLLING */
1152
1153 static netdev_tx_t dscc4_start_xmit(struct sk_buff *skb,
1154                                           struct net_device *dev)
1155 {
1156         struct dscc4_dev_priv *dpriv = dscc4_priv(dev);
1157         struct dscc4_pci_priv *ppriv = dpriv->pci_priv;
1158         struct TxFD *tx_fd;
1159         int next;
1160
1161         next = dpriv->tx_current%TX_RING_SIZE;
1162         dpriv->tx_skbuff[next] = skb;
1163         tx_fd = dpriv->tx_fd + next;
1164         tx_fd->state = FrameEnd | TO_STATE_TX(skb->len);
1165         tx_fd->data = cpu_to_le32(pci_map_single(ppriv->pdev, skb->data, skb->len,
1166                                      PCI_DMA_TODEVICE));
1167         tx_fd->complete = 0x00000000;
1168         tx_fd->jiffies = jiffies;
1169         mb();
1170
1171 #ifdef DSCC4_POLLING
1172         spin_lock(&dpriv->lock);
1173         while (dscc4_tx_poll(dpriv, dev));
1174         spin_unlock(&dpriv->lock);
1175 #endif
1176
1177         dev->trans_start = jiffies;
1178
1179         if (debug > 2)
1180                 dscc4_tx_print(dev, dpriv, "Xmit");
1181         /* To be cleaned(unsigned int)/optimized. Later, ok ? */
1182         if (!((++dpriv->tx_current - dpriv->tx_dirty)%TX_RING_SIZE))
1183                 netif_stop_queue(dev);
1184
1185         if (dscc4_tx_quiescent(dpriv, dev))
1186                 dscc4_do_tx(dpriv, dev);
1187
1188         return NETDEV_TX_OK;
1189 }
1190
1191 static int dscc4_close(struct net_device *dev)
1192 {
1193         struct dscc4_dev_priv *dpriv = dscc4_priv(dev);
1194
1195         del_timer_sync(&dpriv->timer);
1196         netif_stop_queue(dev);
1197
1198         scc_patchl(PowerUp | Vis, 0, dpriv, dev, CCR0);
1199         scc_patchl(0x00050000, 0, dpriv, dev, CCR2);
1200         scc_writel(0xffffffff, dpriv, dev, IMR);
1201
1202         dpriv->flags |= FakeReset;
1203
1204         hdlc_close(dev);
1205
1206         return 0;
1207 }
1208
1209 static inline int dscc4_check_clock_ability(int port)
1210 {
1211         int ret = 0;
1212
1213 #ifdef CONFIG_DSCC4_PCISYNC
1214         if (port >= 2)
1215                 ret = -1;
1216 #endif
1217         return ret;
1218 }
1219
1220 /*
1221  * DS1 p.137: "There are a total of 13 different clocking modes..."
1222  *                                  ^^
1223  * Design choices:
1224  * - by default, assume a clock is provided on pin RxClk/TxClk (clock mode 0a).
1225  *   Clock mode 3b _should_ work but the testing seems to make this point
1226  *   dubious (DIY testing requires setting CCR0 at 0x00000033).
1227  *   This is supposed to provide least surprise "DTE like" behavior.
1228  * - if line rate is specified, clocks are assumed to be locally generated.
1229  *   A quartz must be available (on pin XTAL1). Modes 6b/7b are used. Choosing
1230  *   between these it automagically done according on the required frequency
1231  *   scaling. Of course some rounding may take place.
1232  * - no high speed mode (40Mb/s). May be trivial to do but I don't have an
1233  *   appropriate external clocking device for testing.
1234  * - no time-slot/clock mode 5: shameless lazyness.
1235  *
1236  * The clock signals wiring can be (is ?) manufacturer dependant. Good luck.
1237  *
1238  * BIG FAT WARNING: if the device isn't provided enough clocking signal, it
1239  * won't pass the init sequence. For example, straight back-to-back DTE without
1240  * external clock will fail when dscc4_open() (<- 'ifconfig hdlcx xxx') is
1241  * called.
1242  *
1243  * Typos lurk in datasheet (missing divier in clock mode 7a figure 51 p.153
1244  * DS0 for example)
1245  *
1246  * Clock mode related bits of CCR0:
1247  *     +------------ TOE: output TxClk (0b/2b/3a/3b/6b/7a/7b only)
1248  *     | +---------- SSEL: sub-mode select 0 -> a, 1 -> b
1249  *     | | +-------- High Speed: say 0
1250  *     | | | +-+-+-- Clock Mode: 0..7
1251  *     | | | | | |
1252  * -+-+-+-+-+-+-+-+
1253  * x|x|5|4|3|2|1|0| lower bits
1254  *
1255  * Division factor of BRR: k = (N+1)x2^M (total divider = 16xk in mode 6b)
1256  *            +-+-+-+------------------ M (0..15)
1257  *            | | | |     +-+-+-+-+-+-- N (0..63)
1258  *    0 0 0 0 | | | | 0 0 | | | | | |
1259  * ...-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1260  *    f|e|d|c|b|a|9|8|7|6|5|4|3|2|1|0| lower bits
1261  *
1262  */
1263 static int dscc4_set_clock(struct net_device *dev, u32 *bps, u32 *state)
1264 {
1265         struct dscc4_dev_priv *dpriv = dscc4_priv(dev);
1266         int ret = -1;
1267         u32 brr;
1268
1269         *state &= ~Ccr0ClockMask;
1270         if (*bps) { /* Clock generated - required for DCE */
1271                 u32 n = 0, m = 0, divider;
1272                 int xtal;
1273
1274                 xtal = dpriv->pci_priv->xtal_hz;
1275                 if (!xtal)
1276                         goto done;
1277                 if (dscc4_check_clock_ability(dpriv->dev_id) < 0)
1278                         goto done;
1279                 divider = xtal / *bps;
1280                 if (divider > BRR_DIVIDER_MAX) {
1281                         divider >>= 4;
1282                         *state |= 0x00000036; /* Clock mode 6b (BRG/16) */
1283                 } else
1284                         *state |= 0x00000037; /* Clock mode 7b (BRG) */
1285                 if (divider >> 22) {
1286                         n = 63;
1287                         m = 15;
1288                 } else if (divider) {
1289                         /* Extraction of the 6 highest weighted bits */
1290                         m = 0;
1291                         while (0xffffffc0 & divider) {
1292                                 m++;
1293                                 divider >>= 1;
1294                         }
1295                         n = divider;
1296                 }
1297                 brr = (m << 8) | n;
1298                 divider = n << m;
1299                 if (!(*state & 0x00000001)) /* ?b mode mask => clock mode 6b */
1300                         divider <<= 4;
1301                 *bps = xtal / divider;
1302         } else {
1303                 /*
1304                  * External clock - DTE
1305                  * "state" already reflects Clock mode 0a (CCR0 = 0xzzzzzz00).
1306                  * Nothing more to be done
1307                  */
1308                 brr = 0;
1309         }
1310         scc_writel(brr, dpriv, dev, BRR);
1311         ret = 0;
1312 done:
1313         return ret;
1314 }
1315
1316 static int dscc4_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1317 {
1318         sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
1319         struct dscc4_dev_priv *dpriv = dscc4_priv(dev);
1320         const size_t size = sizeof(dpriv->settings);
1321         int ret = 0;
1322
1323         if (dev->flags & IFF_UP)
1324                 return -EBUSY;
1325
1326         if (cmd != SIOCWANDEV)
1327                 return -EOPNOTSUPP;
1328
1329         switch(ifr->ifr_settings.type) {
1330         case IF_GET_IFACE:
1331                 ifr->ifr_settings.type = IF_IFACE_SYNC_SERIAL;
1332                 if (ifr->ifr_settings.size < size) {
1333                         ifr->ifr_settings.size = size; /* data size wanted */
1334                         return -ENOBUFS;
1335                 }
1336                 if (copy_to_user(line, &dpriv->settings, size))
1337                         return -EFAULT;
1338                 break;
1339
1340         case IF_IFACE_SYNC_SERIAL:
1341                 if (!capable(CAP_NET_ADMIN))
1342                         return -EPERM;
1343
1344                 if (dpriv->flags & FakeReset) {
1345                         printk(KERN_INFO "%s: please reset the device"
1346                                " before this command\n", dev->name);
1347                         return -EPERM;
1348                 }
1349                 if (copy_from_user(&dpriv->settings, line, size))
1350                         return -EFAULT;
1351                 ret = dscc4_set_iface(dpriv, dev);
1352                 break;
1353
1354         default:
1355                 ret = hdlc_ioctl(dev, ifr, cmd);
1356                 break;
1357         }
1358
1359         return ret;
1360 }
1361
1362 static int dscc4_match(struct thingie *p, int value)
1363 {
1364         int i;
1365
1366         for (i = 0; p[i].define != -1; i++) {
1367                 if (value == p[i].define)
1368                         break;
1369         }
1370         if (p[i].define == -1)
1371                 return -1;
1372         else
1373                 return i;
1374 }
1375
1376 static int dscc4_clock_setting(struct dscc4_dev_priv *dpriv,
1377                                struct net_device *dev)
1378 {
1379         sync_serial_settings *settings = &dpriv->settings;
1380         int ret = -EOPNOTSUPP;
1381         u32 bps, state;
1382
1383         bps = settings->clock_rate;
1384         state = scc_readl(dpriv, CCR0);
1385         if (dscc4_set_clock(dev, &bps, &state) < 0)
1386                 goto done;
1387         if (bps) { /* DCE */
1388                 printk(KERN_DEBUG "%s: generated RxClk (DCE)\n", dev->name);
1389                 if (settings->clock_rate != bps) {
1390                         printk(KERN_DEBUG "%s: clock adjusted (%08d -> %08d)\n",
1391                                 dev->name, settings->clock_rate, bps);
1392                         settings->clock_rate = bps;
1393                 }
1394         } else { /* DTE */
1395                 state |= PowerUp | Vis;
1396                 printk(KERN_DEBUG "%s: external RxClk (DTE)\n", dev->name);
1397         }
1398         scc_writel(state, dpriv, dev, CCR0);
1399         ret = 0;
1400 done:
1401         return ret;
1402 }
1403
1404 static int dscc4_encoding_setting(struct dscc4_dev_priv *dpriv,
1405                                   struct net_device *dev)
1406 {
1407         struct thingie encoding[] = {
1408                 { ENCODING_NRZ,         0x00000000 },
1409                 { ENCODING_NRZI,        0x00200000 },
1410                 { ENCODING_FM_MARK,     0x00400000 },
1411                 { ENCODING_FM_SPACE,    0x00500000 },
1412                 { ENCODING_MANCHESTER,  0x00600000 },
1413                 { -1,                   0}
1414         };
1415         int i, ret = 0;
1416
1417         i = dscc4_match(encoding, dpriv->encoding);
1418         if (i >= 0)
1419                 scc_patchl(EncodingMask, encoding[i].bits, dpriv, dev, CCR0);
1420         else
1421                 ret = -EOPNOTSUPP;
1422         return ret;
1423 }
1424
1425 static int dscc4_loopback_setting(struct dscc4_dev_priv *dpriv,
1426                                   struct net_device *dev)
1427 {
1428         sync_serial_settings *settings = &dpriv->settings;
1429         u32 state;
1430
1431         state = scc_readl(dpriv, CCR1);
1432         if (settings->loopback) {
1433                 printk(KERN_DEBUG "%s: loopback\n", dev->name);
1434                 state |= 0x00000100;
1435         } else {
1436                 printk(KERN_DEBUG "%s: normal\n", dev->name);
1437                 state &= ~0x00000100;
1438         }
1439         scc_writel(state, dpriv, dev, CCR1);
1440         return 0;
1441 }
1442
1443 static int dscc4_crc_setting(struct dscc4_dev_priv *dpriv,
1444                              struct net_device *dev)
1445 {
1446         struct thingie crc[] = {
1447                 { PARITY_CRC16_PR0_CCITT,       0x00000010 },
1448                 { PARITY_CRC16_PR1_CCITT,       0x00000000 },
1449                 { PARITY_CRC32_PR0_CCITT,       0x00000011 },
1450                 { PARITY_CRC32_PR1_CCITT,       0x00000001 }
1451         };
1452         int i, ret = 0;
1453
1454         i = dscc4_match(crc, dpriv->parity);
1455         if (i >= 0)
1456                 scc_patchl(CrcMask, crc[i].bits, dpriv, dev, CCR1);
1457         else
1458                 ret = -EOPNOTSUPP;
1459         return ret;
1460 }
1461
1462 static int dscc4_set_iface(struct dscc4_dev_priv *dpriv, struct net_device *dev)
1463 {
1464         struct {
1465                 int (*action)(struct dscc4_dev_priv *, struct net_device *);
1466         } *p, do_setting[] = {
1467                 { dscc4_encoding_setting },
1468                 { dscc4_clock_setting },
1469                 { dscc4_loopback_setting },
1470                 { dscc4_crc_setting },
1471                 { NULL }
1472         };
1473         int ret = 0;
1474
1475         for (p = do_setting; p->action; p++) {
1476                 if ((ret = p->action(dpriv, dev)) < 0)
1477                         break;
1478         }
1479         return ret;
1480 }
1481
1482 static irqreturn_t dscc4_irq(int irq, void *token)
1483 {
1484         struct dscc4_dev_priv *root = token;
1485         struct dscc4_pci_priv *priv;
1486         struct net_device *dev;
1487         void __iomem *ioaddr;
1488         u32 state;
1489         unsigned long flags;
1490         int i, handled = 1;
1491
1492         priv = root->pci_priv;
1493         dev = dscc4_to_dev(root);
1494
1495         spin_lock_irqsave(&priv->lock, flags);
1496
1497         ioaddr = root->base_addr;
1498
1499         state = readl(ioaddr + GSTAR);
1500         if (!state) {
1501                 handled = 0;
1502                 goto out;
1503         }
1504         if (debug > 3)
1505                 printk(KERN_DEBUG "%s: GSTAR = 0x%08x\n", DRV_NAME, state);
1506         writel(state, ioaddr + GSTAR);
1507
1508         if (state & Arf) {
1509                 printk(KERN_ERR "%s: failure (Arf). Harass the maintener\n",
1510                        dev->name);
1511                 goto out;
1512         }
1513         state &= ~ArAck;
1514         if (state & Cfg) {
1515                 if (debug > 0)
1516                         printk(KERN_DEBUG "%s: CfgIV\n", DRV_NAME);
1517                 if (priv->iqcfg[priv->cfg_cur++%IRQ_RING_SIZE] & cpu_to_le32(Arf))
1518                         printk(KERN_ERR "%s: %s failed\n", dev->name, "CFG");
1519                 if (!(state &= ~Cfg))
1520                         goto out;
1521         }
1522         if (state & RxEvt) {
1523                 i = dev_per_card - 1;
1524                 do {
1525                         dscc4_rx_irq(priv, root + i);
1526                 } while (--i >= 0);
1527                 state &= ~RxEvt;
1528         }
1529         if (state & TxEvt) {
1530                 i = dev_per_card - 1;
1531                 do {
1532                         dscc4_tx_irq(priv, root + i);
1533                 } while (--i >= 0);
1534                 state &= ~TxEvt;
1535         }
1536 out:
1537         spin_unlock_irqrestore(&priv->lock, flags);
1538         return IRQ_RETVAL(handled);
1539 }
1540
1541 static void dscc4_tx_irq(struct dscc4_pci_priv *ppriv,
1542                                 struct dscc4_dev_priv *dpriv)
1543 {
1544         struct net_device *dev = dscc4_to_dev(dpriv);
1545         u32 state;
1546         int cur, loop = 0;
1547
1548 try:
1549         cur = dpriv->iqtx_current%IRQ_RING_SIZE;
1550         state = le32_to_cpu(dpriv->iqtx[cur]);
1551         if (!state) {
1552                 if (debug > 4)
1553                         printk(KERN_DEBUG "%s: Tx ISR = 0x%08x\n", dev->name,
1554                                state);
1555                 if ((debug > 1) && (loop > 1))
1556                         printk(KERN_DEBUG "%s: Tx irq loop=%d\n", dev->name, loop);
1557                 if (loop && netif_queue_stopped(dev))
1558                         if ((dpriv->tx_current - dpriv->tx_dirty)%TX_RING_SIZE)
1559                                 netif_wake_queue(dev);
1560
1561                 if (netif_running(dev) && dscc4_tx_quiescent(dpriv, dev) &&
1562                     !dscc4_tx_done(dpriv))
1563                                 dscc4_do_tx(dpriv, dev);
1564                 return;
1565         }
1566         loop++;
1567         dpriv->iqtx[cur] = 0;
1568         dpriv->iqtx_current++;
1569
1570         if (state_check(state, dpriv, dev, "Tx") < 0)
1571                 return;
1572
1573         if (state & SccEvt) {
1574                 if (state & Alls) {
1575                         struct sk_buff *skb;
1576                         struct TxFD *tx_fd;
1577
1578                         if (debug > 2)
1579                                 dscc4_tx_print(dev, dpriv, "Alls");
1580                         /*
1581                          * DataComplete can't be trusted for Tx completion.
1582                          * Cf errata DS5 p.8
1583                          */
1584                         cur = dpriv->tx_dirty%TX_RING_SIZE;
1585                         tx_fd = dpriv->tx_fd + cur;
1586                         skb = dpriv->tx_skbuff[cur];
1587                         if (skb) {
1588                                 pci_unmap_single(ppriv->pdev, le32_to_cpu(tx_fd->data),
1589                                                  skb->len, PCI_DMA_TODEVICE);
1590                                 if (tx_fd->state & FrameEnd) {
1591                                         dev->stats.tx_packets++;
1592                                         dev->stats.tx_bytes += skb->len;
1593                                 }
1594                                 dev_kfree_skb_irq(skb);
1595                                 dpriv->tx_skbuff[cur] = NULL;
1596                                 ++dpriv->tx_dirty;
1597                         } else {
1598                                 if (debug > 1)
1599                                         printk(KERN_ERR "%s Tx: NULL skb %d\n",
1600                                                 dev->name, cur);
1601                         }
1602                         /*
1603                          * If the driver ends sending crap on the wire, it
1604                          * will be way easier to diagnose than the (not so)
1605                          * random freeze induced by null sized tx frames.
1606                          */
1607                         tx_fd->data = tx_fd->next;
1608                         tx_fd->state = FrameEnd | TO_STATE_TX(2*DUMMY_SKB_SIZE);
1609                         tx_fd->complete = 0x00000000;
1610                         tx_fd->jiffies = 0;
1611
1612                         if (!(state &= ~Alls))
1613                                 goto try;
1614                 }
1615                 /*
1616                  * Transmit Data Underrun
1617                  */
1618                 if (state & Xdu) {
1619                         printk(KERN_ERR "%s: XDU. Ask maintainer\n", DRV_NAME);
1620                         dpriv->flags = NeedIDT;
1621                         /* Tx reset */
1622                         writel(MTFi | Rdt,
1623                                dpriv->base_addr + 0x0c*dpriv->dev_id + CH0CFG);
1624                         writel(Action, dpriv->base_addr + GCMDR);
1625                         return;
1626                 }
1627                 if (state & Cts) {
1628                         printk(KERN_INFO "%s: CTS transition\n", dev->name);
1629                         if (!(state &= ~Cts)) /* DEBUG */
1630                                 goto try;
1631                 }
1632                 if (state & Xmr) {
1633                         /* Frame needs to be sent again - FIXME */
1634                         printk(KERN_ERR "%s: Xmr. Ask maintainer\n", DRV_NAME);
1635                         if (!(state &= ~Xmr)) /* DEBUG */
1636                                 goto try;
1637                 }
1638                 if (state & Xpr) {
1639                         void __iomem *scc_addr;
1640                         unsigned long ring;
1641                         int i;
1642
1643                         /*
1644                          * - the busy condition happens (sometimes);
1645                          * - it doesn't seem to make the handler unreliable.
1646                          */
1647                         for (i = 1; i; i <<= 1) {
1648                                 if (!(scc_readl_star(dpriv, dev) & SccBusy))
1649                                         break;
1650                         }
1651                         if (!i)
1652                                 printk(KERN_INFO "%s busy in irq\n", dev->name);
1653
1654                         scc_addr = dpriv->base_addr + 0x0c*dpriv->dev_id;
1655                         /* Keep this order: IDT before IDR */
1656                         if (dpriv->flags & NeedIDT) {
1657                                 if (debug > 2)
1658                                         dscc4_tx_print(dev, dpriv, "Xpr");
1659                                 ring = dpriv->tx_fd_dma +
1660                                        (dpriv->tx_dirty%TX_RING_SIZE)*
1661                                        sizeof(struct TxFD);
1662                                 writel(ring, scc_addr + CH0BTDA);
1663                                 dscc4_do_tx(dpriv, dev);
1664                                 writel(MTFi | Idt, scc_addr + CH0CFG);
1665                                 if (dscc4_do_action(dev, "IDT") < 0)
1666                                         goto err_xpr;
1667                                 dpriv->flags &= ~NeedIDT;
1668                         }
1669                         if (dpriv->flags & NeedIDR) {
1670                                 ring = dpriv->rx_fd_dma +
1671                                        (dpriv->rx_current%RX_RING_SIZE)*
1672                                        sizeof(struct RxFD);
1673                                 writel(ring, scc_addr + CH0BRDA);
1674                                 dscc4_rx_update(dpriv, dev);
1675                                 writel(MTFi | Idr, scc_addr + CH0CFG);
1676                                 if (dscc4_do_action(dev, "IDR") < 0)
1677                                         goto err_xpr;
1678                                 dpriv->flags &= ~NeedIDR;
1679                                 smp_wmb();
1680                                 /* Activate receiver and misc */
1681                                 scc_writel(0x08050008, dpriv, dev, CCR2);
1682                         }
1683                 err_xpr:
1684                         if (!(state &= ~Xpr))
1685                                 goto try;
1686                 }
1687                 if (state & Cd) {
1688                         if (debug > 0)
1689                                 printk(KERN_INFO "%s: CD transition\n", dev->name);
1690                         if (!(state &= ~Cd)) /* DEBUG */
1691                                 goto try;
1692                 }
1693         } else { /* ! SccEvt */
1694                 if (state & Hi) {
1695 #ifdef DSCC4_POLLING
1696                         while (!dscc4_tx_poll(dpriv, dev));
1697 #endif
1698                         printk(KERN_INFO "%s: Tx Hi\n", dev->name);
1699                         state &= ~Hi;
1700                 }
1701                 if (state & Err) {
1702                         printk(KERN_INFO "%s: Tx ERR\n", dev->name);
1703                         dev->stats.tx_errors++;
1704                         state &= ~Err;
1705                 }
1706         }
1707         goto try;
1708 }
1709
1710 static void dscc4_rx_irq(struct dscc4_pci_priv *priv,
1711                                     struct dscc4_dev_priv *dpriv)
1712 {
1713         struct net_device *dev = dscc4_to_dev(dpriv);
1714         u32 state;
1715         int cur;
1716
1717 try:
1718         cur = dpriv->iqrx_current%IRQ_RING_SIZE;
1719         state = le32_to_cpu(dpriv->iqrx[cur]);
1720         if (!state)
1721                 return;
1722         dpriv->iqrx[cur] = 0;
1723         dpriv->iqrx_current++;
1724
1725         if (state_check(state, dpriv, dev, "Rx") < 0)
1726                 return;
1727
1728         if (!(state & SccEvt)){
1729                 struct RxFD *rx_fd;
1730
1731                 if (debug > 4)
1732                         printk(KERN_DEBUG "%s: Rx ISR = 0x%08x\n", dev->name,
1733                                state);
1734                 state &= 0x00ffffff;
1735                 if (state & Err) { /* Hold or reset */
1736                         printk(KERN_DEBUG "%s: Rx ERR\n", dev->name);
1737                         cur = dpriv->rx_current%RX_RING_SIZE;
1738                         rx_fd = dpriv->rx_fd + cur;
1739                         /*
1740                          * Presume we're not facing a DMAC receiver reset.
1741                          * As We use the rx size-filtering feature of the
1742                          * DSCC4, the beginning of a new frame is waiting in
1743                          * the rx fifo. I bet a Receive Data Overflow will
1744                          * happen most of time but let's try and avoid it.
1745                          * Btw (as for RDO) if one experiences ERR whereas
1746                          * the system looks rather idle, there may be a
1747                          * problem with latency. In this case, increasing
1748                          * RX_RING_SIZE may help.
1749                          */
1750                         //while (dpriv->rx_needs_refill) {
1751                                 while (!(rx_fd->state1 & Hold)) {
1752                                         rx_fd++;
1753                                         cur++;
1754                                         if (!(cur = cur%RX_RING_SIZE))
1755                                                 rx_fd = dpriv->rx_fd;
1756                                 }
1757                                 //dpriv->rx_needs_refill--;
1758                                 try_get_rx_skb(dpriv, dev);
1759                                 if (!rx_fd->data)
1760                                         goto try;
1761                                 rx_fd->state1 &= ~Hold;
1762                                 rx_fd->state2 = 0x00000000;
1763                                 rx_fd->end = cpu_to_le32(0xbabeface);
1764                         //}
1765                         goto try;
1766                 }
1767                 if (state & Fi) {
1768                         dscc4_rx_skb(dpriv, dev);
1769                         goto try;
1770                 }
1771                 if (state & Hi ) { /* HI bit */
1772                         printk(KERN_INFO "%s: Rx Hi\n", dev->name);
1773                         state &= ~Hi;
1774                         goto try;
1775                 }
1776         } else { /* SccEvt */
1777                 if (debug > 1) {
1778                         //FIXME: verifier la presence de tous les evenements
1779                 static struct {
1780                         u32 mask;
1781                         const char *irq_name;
1782                 } evts[] = {
1783                         { 0x00008000, "TIN"},
1784                         { 0x00000020, "RSC"},
1785                         { 0x00000010, "PCE"},
1786                         { 0x00000008, "PLLA"},
1787                         { 0, NULL}
1788                 }, *evt;
1789
1790                 for (evt = evts; evt->irq_name; evt++) {
1791                         if (state & evt->mask) {
1792                                         printk(KERN_DEBUG "%s: %s\n",
1793                                                 dev->name, evt->irq_name);
1794                                 if (!(state &= ~evt->mask))
1795                                         goto try;
1796                         }
1797                 }
1798                 } else {
1799                         if (!(state &= ~0x0000c03c))
1800                                 goto try;
1801                 }
1802                 if (state & Cts) {
1803                         printk(KERN_INFO "%s: CTS transition\n", dev->name);
1804                         if (!(state &= ~Cts)) /* DEBUG */
1805                                 goto try;
1806                 }
1807                 /*
1808                  * Receive Data Overflow (FIXME: fscked)
1809                  */
1810                 if (state & Rdo) {
1811                         struct RxFD *rx_fd;
1812                         void __iomem *scc_addr;
1813                         int cur;
1814
1815                         //if (debug)
1816                         //      dscc4_rx_dump(dpriv);
1817                         scc_addr = dpriv->base_addr + 0x0c*dpriv->dev_id;
1818
1819                         scc_patchl(RxActivate, 0, dpriv, dev, CCR2);
1820                         /*
1821                          * This has no effect. Why ?
1822                          * ORed with TxSccRes, one sees the CFG ack (for
1823                          * the TX part only).
1824                          */
1825                         scc_writel(RxSccRes, dpriv, dev, CMDR);
1826                         dpriv->flags |= RdoSet;
1827
1828                         /*
1829                          * Let's try and save something in the received data.
1830                          * rx_current must be incremented at least once to
1831                          * avoid HOLD in the BRDA-to-be-pointed desc.
1832                          */
1833                         do {
1834                                 cur = dpriv->rx_current++%RX_RING_SIZE;
1835                                 rx_fd = dpriv->rx_fd + cur;
1836                                 if (!(rx_fd->state2 & DataComplete))
1837                                         break;
1838                                 if (rx_fd->state2 & FrameAborted) {
1839                                         dev->stats.rx_over_errors++;
1840                                         rx_fd->state1 |= Hold;
1841                                         rx_fd->state2 = 0x00000000;
1842                                         rx_fd->end = cpu_to_le32(0xbabeface);
1843                                 } else
1844                                         dscc4_rx_skb(dpriv, dev);
1845                         } while (1);
1846
1847                         if (debug > 0) {
1848                                 if (dpriv->flags & RdoSet)
1849                                         printk(KERN_DEBUG
1850                                                "%s: no RDO in Rx data\n", DRV_NAME);
1851                         }
1852 #ifdef DSCC4_RDO_EXPERIMENTAL_RECOVERY
1853                         /*
1854                          * FIXME: must the reset be this violent ?
1855                          */
1856 #warning "FIXME: CH0BRDA"
1857                         writel(dpriv->rx_fd_dma +
1858                                (dpriv->rx_current%RX_RING_SIZE)*
1859                                sizeof(struct RxFD), scc_addr + CH0BRDA);
1860                         writel(MTFi|Rdr|Idr, scc_addr + CH0CFG);
1861                         if (dscc4_do_action(dev, "RDR") < 0) {
1862                                 printk(KERN_ERR "%s: RDO recovery failed(%s)\n",
1863                                        dev->name, "RDR");
1864                                 goto rdo_end;
1865                         }
1866                         writel(MTFi|Idr, scc_addr + CH0CFG);
1867                         if (dscc4_do_action(dev, "IDR") < 0) {
1868                                 printk(KERN_ERR "%s: RDO recovery failed(%s)\n",
1869                                        dev->name, "IDR");
1870                                 goto rdo_end;
1871                         }
1872                 rdo_end:
1873 #endif
1874                         scc_patchl(0, RxActivate, dpriv, dev, CCR2);
1875                         goto try;
1876                 }
1877                 if (state & Cd) {
1878                         printk(KERN_INFO "%s: CD transition\n", dev->name);
1879                         if (!(state &= ~Cd)) /* DEBUG */
1880                                 goto try;
1881                 }
1882                 if (state & Flex) {
1883                         printk(KERN_DEBUG "%s: Flex. Ttttt...\n", DRV_NAME);
1884                         if (!(state &= ~Flex))
1885                                 goto try;
1886                 }
1887         }
1888 }
1889
1890 /*
1891  * I had expected the following to work for the first descriptor
1892  * (tx_fd->state = 0xc0000000)
1893  * - Hold=1 (don't try and branch to the next descripto);
1894  * - No=0 (I want an empty data section, i.e. size=0);
1895  * - Fe=1 (required by No=0 or we got an Err irq and must reset).
1896  * It failed and locked solid. Thus the introduction of a dummy skb.
1897  * Problem is acknowledged in errata sheet DS5. Joy :o/
1898  */
1899 static struct sk_buff *dscc4_init_dummy_skb(struct dscc4_dev_priv *dpriv)
1900 {
1901         struct sk_buff *skb;
1902
1903         skb = dev_alloc_skb(DUMMY_SKB_SIZE);
1904         if (skb) {
1905                 int last = dpriv->tx_dirty%TX_RING_SIZE;
1906                 struct TxFD *tx_fd = dpriv->tx_fd + last;
1907
1908                 skb->len = DUMMY_SKB_SIZE;
1909                 skb_copy_to_linear_data(skb, version,
1910                                         strlen(version) % DUMMY_SKB_SIZE);
1911                 tx_fd->state = FrameEnd | TO_STATE_TX(DUMMY_SKB_SIZE);
1912                 tx_fd->data = cpu_to_le32(pci_map_single(dpriv->pci_priv->pdev,
1913                                              skb->data, DUMMY_SKB_SIZE,
1914                                              PCI_DMA_TODEVICE));
1915                 dpriv->tx_skbuff[last] = skb;
1916         }
1917         return skb;
1918 }
1919
1920 static int dscc4_init_ring(struct net_device *dev)
1921 {
1922         struct dscc4_dev_priv *dpriv = dscc4_priv(dev);
1923         struct pci_dev *pdev = dpriv->pci_priv->pdev;
1924         struct TxFD *tx_fd;
1925         struct RxFD *rx_fd;
1926         void *ring;
1927         int i;
1928
1929         ring = pci_alloc_consistent(pdev, RX_TOTAL_SIZE, &dpriv->rx_fd_dma);
1930         if (!ring)
1931                 goto err_out;
1932         dpriv->rx_fd = rx_fd = (struct RxFD *) ring;
1933
1934         ring = pci_alloc_consistent(pdev, TX_TOTAL_SIZE, &dpriv->tx_fd_dma);
1935         if (!ring)
1936                 goto err_free_dma_rx;
1937         dpriv->tx_fd = tx_fd = (struct TxFD *) ring;
1938
1939         memset(dpriv->tx_skbuff, 0, sizeof(struct sk_buff *)*TX_RING_SIZE);
1940         dpriv->tx_dirty = 0xffffffff;
1941         i = dpriv->tx_current = 0;
1942         do {
1943                 tx_fd->state = FrameEnd | TO_STATE_TX(2*DUMMY_SKB_SIZE);
1944                 tx_fd->complete = 0x00000000;
1945                 /* FIXME: NULL should be ok - to be tried */
1946                 tx_fd->data = cpu_to_le32(dpriv->tx_fd_dma);
1947                 (tx_fd++)->next = cpu_to_le32(dpriv->tx_fd_dma +
1948                                         (++i%TX_RING_SIZE)*sizeof(*tx_fd));
1949         } while (i < TX_RING_SIZE);
1950
1951         if (!dscc4_init_dummy_skb(dpriv))
1952                 goto err_free_dma_tx;
1953
1954         memset(dpriv->rx_skbuff, 0, sizeof(struct sk_buff *)*RX_RING_SIZE);
1955         i = dpriv->rx_dirty = dpriv->rx_current = 0;
1956         do {
1957                 /* size set by the host. Multiple of 4 bytes please */
1958                 rx_fd->state1 = HiDesc;
1959                 rx_fd->state2 = 0x00000000;
1960                 rx_fd->end = cpu_to_le32(0xbabeface);
1961                 rx_fd->state1 |= TO_STATE_RX(HDLC_MAX_MRU);
1962                 // FIXME: return value verifiee mais traitement suspect
1963                 if (try_get_rx_skb(dpriv, dev) >= 0)
1964                         dpriv->rx_dirty++;
1965                 (rx_fd++)->next = cpu_to_le32(dpriv->rx_fd_dma +
1966                                         (++i%RX_RING_SIZE)*sizeof(*rx_fd));
1967         } while (i < RX_RING_SIZE);
1968
1969         return 0;
1970
1971 err_free_dma_tx:
1972         pci_free_consistent(pdev, TX_TOTAL_SIZE, ring, dpriv->tx_fd_dma);
1973 err_free_dma_rx:
1974         pci_free_consistent(pdev, RX_TOTAL_SIZE, rx_fd, dpriv->rx_fd_dma);
1975 err_out:
1976         return -ENOMEM;
1977 }
1978
1979 static void __devexit dscc4_remove_one(struct pci_dev *pdev)
1980 {
1981         struct dscc4_pci_priv *ppriv;
1982         struct dscc4_dev_priv *root;
1983         void __iomem *ioaddr;
1984         int i;
1985
1986         ppriv = pci_get_drvdata(pdev);
1987         root = ppriv->root;
1988
1989         ioaddr = root->base_addr;
1990
1991         dscc4_pci_reset(pdev, ioaddr);
1992
1993         free_irq(pdev->irq, root);
1994         pci_free_consistent(pdev, IRQ_RING_SIZE*sizeof(u32), ppriv->iqcfg,
1995                             ppriv->iqcfg_dma);
1996         for (i = 0; i < dev_per_card; i++) {
1997                 struct dscc4_dev_priv *dpriv = root + i;
1998
1999                 dscc4_release_ring(dpriv);
2000                 pci_free_consistent(pdev, IRQ_RING_SIZE*sizeof(u32),
2001                                     dpriv->iqrx, dpriv->iqrx_dma);
2002                 pci_free_consistent(pdev, IRQ_RING_SIZE*sizeof(u32),
2003                                     dpriv->iqtx, dpriv->iqtx_dma);
2004         }
2005
2006         dscc4_free1(pdev);
2007
2008         iounmap(ioaddr);
2009
2010         pci_release_region(pdev, 1);
2011         pci_release_region(pdev, 0);
2012
2013         pci_disable_device(pdev);
2014 }
2015
2016 static int dscc4_hdlc_attach(struct net_device *dev, unsigned short encoding,
2017         unsigned short parity)
2018 {
2019         struct dscc4_dev_priv *dpriv = dscc4_priv(dev);
2020
2021         if (encoding != ENCODING_NRZ &&
2022             encoding != ENCODING_NRZI &&
2023             encoding != ENCODING_FM_MARK &&
2024             encoding != ENCODING_FM_SPACE &&
2025             encoding != ENCODING_MANCHESTER)
2026                 return -EINVAL;
2027
2028         if (parity != PARITY_NONE &&
2029             parity != PARITY_CRC16_PR0_CCITT &&
2030             parity != PARITY_CRC16_PR1_CCITT &&
2031             parity != PARITY_CRC32_PR0_CCITT &&
2032             parity != PARITY_CRC32_PR1_CCITT)
2033                 return -EINVAL;
2034
2035         dpriv->encoding = encoding;
2036         dpriv->parity = parity;
2037         return 0;
2038 }
2039
2040 #ifndef MODULE
2041 static int __init dscc4_setup(char *str)
2042 {
2043         int *args[] = { &debug, &quartz, NULL }, **p = args;
2044
2045         while (*p && (get_option(&str, *p) == 2))
2046                 p++;
2047         return 1;
2048 }
2049
2050 __setup("dscc4.setup=", dscc4_setup);
2051 #endif
2052
2053 static struct pci_device_id dscc4_pci_tbl[] = {
2054         { PCI_VENDOR_ID_SIEMENS, PCI_DEVICE_ID_SIEMENS_DSCC4,
2055                 PCI_ANY_ID, PCI_ANY_ID, },
2056         { 0,}
2057 };
2058 MODULE_DEVICE_TABLE(pci, dscc4_pci_tbl);
2059
2060 static struct pci_driver dscc4_driver = {
2061         .name           = DRV_NAME,
2062         .id_table       = dscc4_pci_tbl,
2063         .probe          = dscc4_init_one,
2064         .remove         = __devexit_p(dscc4_remove_one),
2065 };
2066
2067 static int __init dscc4_init_module(void)
2068 {
2069         return pci_register_driver(&dscc4_driver);
2070 }
2071
2072 static void __exit dscc4_cleanup_module(void)
2073 {
2074         pci_unregister_driver(&dscc4_driver);
2075 }
2076
2077 module_init(dscc4_init_module);
2078 module_exit(dscc4_cleanup_module);