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