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