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tracing/ring-buffer: Add unlock recursion protection on discard
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / net / wan / hd64572.c
blob497b003d72392a1ba87968ba3ea8fc47b077f610
1 /*
2 * Hitachi (now Renesas) SCA-II HD64572 driver for Linux
3 *
4 * Copyright (C) 1998-2008 Krzysztof Halasa <khc@pm.waw.pl>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of version 2 of the GNU General Public License
8 * as published by the Free Software Foundation.
9 *
10 * Source of information: HD64572 SCA-II User's Manual
11 *
12 * We use the following SCA memory map:
13 *
14 * Packet buffer descriptor rings - starting from card->rambase:
15 * rx_ring_buffers * sizeof(pkt_desc) = logical channel #0 RX ring
16 * tx_ring_buffers * sizeof(pkt_desc) = logical channel #0 TX ring
17 * rx_ring_buffers * sizeof(pkt_desc) = logical channel #1 RX ring (if used)
18 * tx_ring_buffers * sizeof(pkt_desc) = logical channel #1 TX ring (if used)
19 *
20 * Packet data buffers - starting from card->rambase + buff_offset:
21 * rx_ring_buffers * HDLC_MAX_MRU = logical channel #0 RX buffers
22 * tx_ring_buffers * HDLC_MAX_MRU = logical channel #0 TX buffers
23 * rx_ring_buffers * HDLC_MAX_MRU = logical channel #0 RX buffers (if used)
24 * tx_ring_buffers * HDLC_MAX_MRU = logical channel #0 TX buffers (if used)
25 */
26
27 #include <linux/bitops.h>
28 #include <linux/errno.h>
29 #include <linux/fcntl.h>
30 #include <linux/hdlc.h>
31 #include <linux/in.h>
32 #include <linux/init.h>
33 #include <linux/interrupt.h>
34 #include <linux/ioport.h>
35 #include <linux/jiffies.h>
36 #include <linux/kernel.h>
37 #include <linux/module.h>
38 #include <linux/netdevice.h>
39 #include <linux/skbuff.h>
40 #include <linux/slab.h>
41 #include <linux/string.h>
42 #include <linux/types.h>
43 #include <asm/io.h>
44 #include <asm/system.h>
45 #include <asm/uaccess.h>
46 #include "hd64572.h"
47
48 #define NAPI_WEIGHT 16
49
50 #define get_msci(port) (port->chan ? MSCI1_OFFSET : MSCI0_OFFSET)
51 #define get_dmac_rx(port) (port->chan ? DMAC1RX_OFFSET : DMAC0RX_OFFSET)
52 #define get_dmac_tx(port) (port->chan ? DMAC1TX_OFFSET : DMAC0TX_OFFSET)
53
54 #define sca_in(reg, card) readb(card->scabase + (reg))
55 #define sca_out(value, reg, card) writeb(value, card->scabase + (reg))
56 #define sca_inw(reg, card) readw(card->scabase + (reg))
57 #define sca_outw(value, reg, card) writew(value, card->scabase + (reg))
58 #define sca_inl(reg, card) readl(card->scabase + (reg))
59 #define sca_outl(value, reg, card) writel(value, card->scabase + (reg))
60
61 static int sca_poll(struct napi_struct *napi, int budget);
62
63 static inline port_t* dev_to_port(struct net_device *dev)
64 {
65 return dev_to_hdlc(dev)->priv;
66 }
67
68 static inline void enable_intr(port_t *port)
69 {
70 /* enable DMIB and MSCI RXINTA interrupts */
71 sca_outl(sca_inl(IER0, port->card) |
72 (port->chan ? 0x08002200 : 0x00080022), IER0, port->card);
73 }
74
75 static inline void disable_intr(port_t *port)
76 {
77 sca_outl(sca_inl(IER0, port->card) &
78 (port->chan ? 0x00FF00FF : 0xFF00FF00), IER0, port->card);
79 }
80
81 static inline u16 desc_abs_number(port_t *port, u16 desc, int transmit)
82 {
83 u16 rx_buffs = port->card->rx_ring_buffers;
84 u16 tx_buffs = port->card->tx_ring_buffers;
85
86 desc %= (transmit ? tx_buffs : rx_buffs); // called with "X + 1" etc.
87 return port->chan * (rx_buffs + tx_buffs) + transmit * rx_buffs + desc;
88 }
89
90
91 static inline u16 desc_offset(port_t *port, u16 desc, int transmit)
92 {
93 /* Descriptor offset always fits in 16 bits */
94 return desc_abs_number(port, desc, transmit) * sizeof(pkt_desc);
95 }
96
97
98 static inline pkt_desc __iomem *desc_address(port_t *port, u16 desc,
99 int transmit)
100 {
101 return (pkt_desc __iomem *)(port->card->rambase +
102 desc_offset(port, desc, transmit));
103 }
104
105
106 static inline u32 buffer_offset(port_t *port, u16 desc, int transmit)
107 {
108 return port->card->buff_offset +
109 desc_abs_number(port, desc, transmit) * (u32)HDLC_MAX_MRU;
110 }
111
112
113 static inline void sca_set_carrier(port_t *port)
114 {
115 if (!(sca_in(get_msci(port) + ST3, port->card) & ST3_DCD)) {
116 #ifdef DEBUG_LINK
117 printk(KERN_DEBUG "%s: sca_set_carrier on\n",
118 port->netdev.name);
119 #endif
120 netif_carrier_on(port->netdev);
121 } else {
122 #ifdef DEBUG_LINK
123 printk(KERN_DEBUG "%s: sca_set_carrier off\n",
124 port->netdev.name);
125 #endif
126 netif_carrier_off(port->netdev);
127 }
128 }
129
130
131 static void sca_init_port(port_t *port)
132 {
133 card_t *card = port->card;
134 u16 dmac_rx = get_dmac_rx(port), dmac_tx = get_dmac_tx(port);
135 int transmit, i;
136
137 port->rxin = 0;
138 port->txin = 0;
139 port->txlast = 0;
140
141 for (transmit = 0; transmit < 2; transmit++) {
142 u16 buffs = transmit ? card->tx_ring_buffers
143 : card->rx_ring_buffers;
144
145 for (i = 0; i < buffs; i++) {
146 pkt_desc __iomem *desc = desc_address(port, i, transmit);
147 u16 chain_off = desc_offset(port, i + 1, transmit);
148 u32 buff_off = buffer_offset(port, i, transmit);
149
150 writel(chain_off, &desc->cp);
151 writel(buff_off, &desc->bp);
152 writew(0, &desc->len);
153 writeb(0, &desc->stat);
154 }
155 }
156
157 /* DMA disable - to halt state */
158 sca_out(0, DSR_RX(port->chan), card);
159 sca_out(0, DSR_TX(port->chan), card);
160
161 /* software ABORT - to initial state */
162 sca_out(DCR_ABORT, DCR_RX(port->chan), card);
163 sca_out(DCR_ABORT, DCR_TX(port->chan), card);
164
165 /* current desc addr */
166 sca_outl(desc_offset(port, 0, 0), dmac_rx + CDAL, card);
167 sca_outl(desc_offset(port, card->tx_ring_buffers - 1, 0),
168 dmac_rx + EDAL, card);
169 sca_outl(desc_offset(port, 0, 1), dmac_tx + CDAL, card);
170 sca_outl(desc_offset(port, 0, 1), dmac_tx + EDAL, card);
171
172 /* clear frame end interrupt counter */
173 sca_out(DCR_CLEAR_EOF, DCR_RX(port->chan), card);
174 sca_out(DCR_CLEAR_EOF, DCR_TX(port->chan), card);
175
176 /* Receive */
177 sca_outw(HDLC_MAX_MRU, dmac_rx + BFLL, card); /* set buffer length */
178 sca_out(0x14, DMR_RX(port->chan), card); /* Chain mode, Multi-frame */
179 sca_out(DIR_EOME, DIR_RX(port->chan), card); /* enable interrupts */
180 sca_out(DSR_DE, DSR_RX(port->chan), card); /* DMA enable */
181
182 /* Transmit */
183 sca_out(0x14, DMR_TX(port->chan), card); /* Chain mode, Multi-frame */
184 sca_out(DIR_EOME, DIR_TX(port->chan), card); /* enable interrupts */
185
186 sca_set_carrier(port);
187 netif_napi_add(port->netdev, &port->napi, sca_poll, NAPI_WEIGHT);
188 }
189
190
191 /* MSCI interrupt service */
192 static inline void sca_msci_intr(port_t *port)
193 {
194 u16 msci = get_msci(port);
195 card_t* card = port->card;
196
197 if (sca_in(msci + ST1, card) & ST1_CDCD) {
198 /* Reset MSCI CDCD status bit */
199 sca_out(ST1_CDCD, msci + ST1, card);
200 sca_set_carrier(port);
201 }
202 }
203
204
205 static inline void sca_rx(card_t *card, port_t *port, pkt_desc __iomem *desc,
206 u16 rxin)
207 {
208 struct net_device *dev = port->netdev;
209 struct sk_buff *skb;
210 u16 len;
211 u32 buff;
212
213 len = readw(&desc->len);
214 skb = dev_alloc_skb(len);
215 if (!skb) {
216 dev->stats.rx_dropped++;
217 return;
218 }
219
220 buff = buffer_offset(port, rxin, 0);
221 memcpy_fromio(skb->data, card->rambase + buff, len);
222
223 skb_put(skb, len);
224 #ifdef DEBUG_PKT
225 printk(KERN_DEBUG "%s RX(%i):", dev->name, skb->len);
226 debug_frame(skb);
227 #endif
228 dev->stats.rx_packets++;
229 dev->stats.rx_bytes += skb->len;
230 skb->protocol = hdlc_type_trans(skb, dev);
231 netif_receive_skb(skb);
232 }
233
234
235 /* Receive DMA service */
236 static inline int sca_rx_done(port_t *port, int budget)
237 {
238 struct net_device *dev = port->netdev;
239 u16 dmac = get_dmac_rx(port);
240 card_t *card = port->card;
241 u8 stat = sca_in(DSR_RX(port->chan), card); /* read DMA Status */
242 int received = 0;
243
244 /* Reset DSR status bits */
245 sca_out((stat & (DSR_EOT | DSR_EOM | DSR_BOF | DSR_COF)) | DSR_DWE,
246 DSR_RX(port->chan), card);
247
248 if (stat & DSR_BOF)
249 /* Dropped one or more frames */
250 dev->stats.rx_over_errors++;
251
252 while (received < budget) {
253 u32 desc_off = desc_offset(port, port->rxin, 0);
254 pkt_desc __iomem *desc;
255 u32 cda = sca_inl(dmac + CDAL, card);
256
257 if ((cda >= desc_off) && (cda < desc_off + sizeof(pkt_desc)))
258 break; /* No frame received */
259
260 desc = desc_address(port, port->rxin, 0);
261 stat = readb(&desc->stat);
262 if (!(stat & ST_RX_EOM))
263 port->rxpart = 1; /* partial frame received */
264 else if ((stat & ST_ERROR_MASK) || port->rxpart) {
265 dev->stats.rx_errors++;
266 if (stat & ST_RX_OVERRUN)
267 dev->stats.rx_fifo_errors++;
268 else if ((stat & (ST_RX_SHORT | ST_RX_ABORT |
269 ST_RX_RESBIT)) || port->rxpart)
270 dev->stats.rx_frame_errors++;
271 else if (stat & ST_RX_CRC)
272 dev->stats.rx_crc_errors++;
273 if (stat & ST_RX_EOM)
274 port->rxpart = 0; /* received last fragment */
275 } else {
276 sca_rx(card, port, desc, port->rxin);
277 received++;
278 }
279
280 /* Set new error descriptor address */
281 sca_outl(desc_off, dmac + EDAL, card);
282 port->rxin = (port->rxin + 1) % card->rx_ring_buffers;
283 }
284
285 /* make sure RX DMA is enabled */
286 sca_out(DSR_DE, DSR_RX(port->chan), card);
287 return received;
288 }
289
290
291 /* Transmit DMA service */
292 static inline void sca_tx_done(port_t *port)
293 {
294 struct net_device *dev = port->netdev;
295 card_t* card = port->card;
296 u8 stat;
297
298 spin_lock(&port->lock);
299
300 stat = sca_in(DSR_TX(port->chan), card); /* read DMA Status */
301
302 /* Reset DSR status bits */
303 sca_out((stat & (DSR_EOT | DSR_EOM | DSR_BOF | DSR_COF)) | DSR_DWE,
304 DSR_TX(port->chan), card);
305
306 while (1) {
307 pkt_desc __iomem *desc = desc_address(port, port->txlast, 1);
308 u8 stat = readb(&desc->stat);
309
310 if (!(stat & ST_TX_OWNRSHP))
311 break; /* not yet transmitted */
312 if (stat & ST_TX_UNDRRUN) {
313 dev->stats.tx_errors++;
314 dev->stats.tx_fifo_errors++;
315 } else {
316 dev->stats.tx_packets++;
317 dev->stats.tx_bytes += readw(&desc->len);
318 }
319 writeb(0, &desc->stat); /* Free descriptor */
320 port->txlast = (port->txlast + 1) % card->tx_ring_buffers;
321 }
322
323 netif_wake_queue(dev);
324 spin_unlock(&port->lock);
325 }
326
327
328 static int sca_poll(struct napi_struct *napi, int budget)
329 {
330 port_t *port = container_of(napi, port_t, napi);
331 u32 isr0 = sca_inl(ISR0, port->card);
332 int received = 0;
333
334 if (isr0 & (port->chan ? 0x08000000 : 0x00080000))
335 sca_msci_intr(port);
336
337 if (isr0 & (port->chan ? 0x00002000 : 0x00000020))
338 sca_tx_done(port);
339
340 if (isr0 & (port->chan ? 0x00000200 : 0x00000002))
341 received = sca_rx_done(port, budget);
342
343 if (received < budget) {
344 napi_complete(napi);
345 enable_intr(port);
346 }
347
348 return received;
349 }
350
351 static irqreturn_t sca_intr(int irq, void *dev_id)
352 {
353 card_t *card = dev_id;
354 u32 isr0 = sca_inl(ISR0, card);
355 int i, handled = 0;
356
357 for (i = 0; i < 2; i++) {
358 port_t *port = get_port(card, i);
359 if (port && (isr0 & (i ? 0x08002200 : 0x00080022))) {
360 handled = 1;
361 disable_intr(port);
362 napi_schedule(&port->napi);
363 }
364 }
365
366 return IRQ_RETVAL(handled);
367 }
368
369
370 static void sca_set_port(port_t *port)
371 {
372 card_t* card = port->card;
373 u16 msci = get_msci(port);
374 u8 md2 = sca_in(msci + MD2, card);
375 unsigned int tmc, br = 10, brv = 1024;
376
377
378 if (port->settings.clock_rate > 0) {
379 /* Try lower br for better accuracy*/
380 do {
381 br--;
382 brv >>= 1; /* brv = 2^9 = 512 max in specs */
383
384 /* Baud Rate = CLOCK_BASE / TMC / 2^BR */
385 tmc = CLOCK_BASE / brv / port->settings.clock_rate;
386 }while (br > 1 && tmc <= 128);
387
388 if (tmc < 1) {
389 tmc = 1;
390 br = 0; /* For baud=CLOCK_BASE we use tmc=1 br=0 */
391 brv = 1;
392 } else if (tmc > 255)
393 tmc = 256; /* tmc=0 means 256 - low baud rates */
394
395 port->settings.clock_rate = CLOCK_BASE / brv / tmc;
396 } else {
397 br = 9; /* Minimum clock rate */
398 tmc = 256; /* 8bit = 0 */
399 port->settings.clock_rate = CLOCK_BASE / (256 * 512);
400 }
401
402 port->rxs = (port->rxs & ~CLK_BRG_MASK) | br;
403 port->txs = (port->txs & ~CLK_BRG_MASK) | br;
404 port->tmc = tmc;
405
406 /* baud divisor - time constant*/
407 sca_out(port->tmc, msci + TMCR, card);
408 sca_out(port->tmc, msci + TMCT, card);
409
410 /* Set BRG bits */
411 sca_out(port->rxs, msci + RXS, card);
412 sca_out(port->txs, msci + TXS, card);
413
414 if (port->settings.loopback)
415 md2 |= MD2_LOOPBACK;
416 else
417 md2 &= ~MD2_LOOPBACK;
418
419 sca_out(md2, msci + MD2, card);
420
421 }
422
423
424 static void sca_open(struct net_device *dev)
425 {
426 port_t *port = dev_to_port(dev);
427 card_t* card = port->card;
428 u16 msci = get_msci(port);
429 u8 md0, md2;
430
431 switch(port->encoding) {
432 case ENCODING_NRZ: md2 = MD2_NRZ; break;
433 case ENCODING_NRZI: md2 = MD2_NRZI; break;
434 case ENCODING_FM_MARK: md2 = MD2_FM_MARK; break;
435 case ENCODING_FM_SPACE: md2 = MD2_FM_SPACE; break;
436 default: md2 = MD2_MANCHESTER;
437 }
438
439 if (port->settings.loopback)
440 md2 |= MD2_LOOPBACK;
441
442 switch(port->parity) {
443 case PARITY_CRC16_PR0: md0 = MD0_HDLC | MD0_CRC_16_0; break;
444 case PARITY_CRC16_PR1: md0 = MD0_HDLC | MD0_CRC_16; break;
445 case PARITY_CRC32_PR1_CCITT: md0 = MD0_HDLC | MD0_CRC_ITU32; break;
446 case PARITY_CRC16_PR1_CCITT: md0 = MD0_HDLC | MD0_CRC_ITU; break;
447 default: md0 = MD0_HDLC | MD0_CRC_NONE;
448 }
449
450 sca_out(CMD_RESET, msci + CMD, card);
451 sca_out(md0, msci + MD0, card);
452 sca_out(0x00, msci + MD1, card); /* no address field check */
453 sca_out(md2, msci + MD2, card);
454 sca_out(0x7E, msci + IDL, card); /* flag character 0x7E */
455 /* Skip the rest of underrun frame */
456 sca_out(CTL_IDLE | CTL_URCT | CTL_URSKP, msci + CTL, card);
457 sca_out(0x0F, msci + RNR, card); /* +1=RX DMA activation condition */
458 sca_out(0x3C, msci + TFS, card); /* +1 = TX start */
459 sca_out(0x38, msci + TCR, card); /* =Critical TX DMA activ condition */
460 sca_out(0x38, msci + TNR0, card); /* =TX DMA activation condition */
461 sca_out(0x3F, msci + TNR1, card); /* +1=TX DMA deactivation condition*/
462
463 /* We're using the following interrupts:
464 - RXINTA (DCD changes only)
465 - DMIB (EOM - single frame transfer complete)
466 */
467 sca_outl(IE0_RXINTA | IE0_CDCD, msci + IE0, card);
468
469 sca_out(port->tmc, msci + TMCR, card);
470 sca_out(port->tmc, msci + TMCT, card);
471 sca_out(port->rxs, msci + RXS, card);
472 sca_out(port->txs, msci + TXS, card);
473 sca_out(CMD_TX_ENABLE, msci + CMD, card);
474 sca_out(CMD_RX_ENABLE, msci + CMD, card);
475
476 sca_set_carrier(port);
477 enable_intr(port);
478 napi_enable(&port->napi);
479 netif_start_queue(dev);
480 }
481
482
483 static void sca_close(struct net_device *dev)
484 {
485 port_t *port = dev_to_port(dev);
486
487 /* reset channel */
488 sca_out(CMD_RESET, get_msci(port) + CMD, port->card);
489 disable_intr(port);
490 napi_disable(&port->napi);
491 netif_stop_queue(dev);
492 }
493
494
495 static int sca_attach(struct net_device *dev, unsigned short encoding,
496 unsigned short parity)
497 {
498 if (encoding != ENCODING_NRZ &&
499 encoding != ENCODING_NRZI &&
500 encoding != ENCODING_FM_MARK &&
501 encoding != ENCODING_FM_SPACE &&
502 encoding != ENCODING_MANCHESTER)
503 return -EINVAL;
504
505 if (parity != PARITY_NONE &&
506 parity != PARITY_CRC16_PR0 &&
507 parity != PARITY_CRC16_PR1 &&
508 parity != PARITY_CRC32_PR1_CCITT &&
509 parity != PARITY_CRC16_PR1_CCITT)
510 return -EINVAL;
511
512 dev_to_port(dev)->encoding = encoding;
513 dev_to_port(dev)->parity = parity;
514 return 0;
515 }
516
517
518 #ifdef DEBUG_RINGS
519 static void sca_dump_rings(struct net_device *dev)
520 {
521 port_t *port = dev_to_port(dev);
522 card_t *card = port->card;
523 u16 cnt;
524
525 printk(KERN_DEBUG "RX ring: CDA=%u EDA=%u DSR=%02X in=%u %sactive",
526 sca_inl(get_dmac_rx(port) + CDAL, card),
527 sca_inl(get_dmac_rx(port) + EDAL, card),
528 sca_in(DSR_RX(port->chan), card), port->rxin,
529 sca_in(DSR_RX(port->chan), card) & DSR_DE ? "" : "in");
530 for (cnt = 0; cnt < port->card->rx_ring_buffers; cnt++)
531 printk(" %02X", readb(&(desc_address(port, cnt, 0)->stat)));
532
533 printk("\n" KERN_DEBUG "TX ring: CDA=%u EDA=%u DSR=%02X in=%u "
534 "last=%u %sactive",
535 sca_inl(get_dmac_tx(port) + CDAL, card),
536 sca_inl(get_dmac_tx(port) + EDAL, card),
537 sca_in(DSR_TX(port->chan), card), port->txin, port->txlast,
538 sca_in(DSR_TX(port->chan), card) & DSR_DE ? "" : "in");
539
540 for (cnt = 0; cnt < port->card->tx_ring_buffers; cnt++)
541 printk(" %02X", readb(&(desc_address(port, cnt, 1)->stat)));
542 printk("\n");
543
544 printk(KERN_DEBUG "MSCI: MD: %02x %02x %02x,"
545 " ST: %02x %02x %02x %02x %02x, FST: %02x CST: %02x %02x\n",
546 sca_in(get_msci(port) + MD0, card),
547 sca_in(get_msci(port) + MD1, card),
548 sca_in(get_msci(port) + MD2, card),
549 sca_in(get_msci(port) + ST0, card),
550 sca_in(get_msci(port) + ST1, card),
551 sca_in(get_msci(port) + ST2, card),
552 sca_in(get_msci(port) + ST3, card),
553 sca_in(get_msci(port) + ST4, card),
554 sca_in(get_msci(port) + FST, card),
555 sca_in(get_msci(port) + CST0, card),
556 sca_in(get_msci(port) + CST1, card));
557
558 printk(KERN_DEBUG "ILAR: %02x ISR: %08x %08x\n", sca_in(ILAR, card),
559 sca_inl(ISR0, card), sca_inl(ISR1, card));
560 }
561 #endif /* DEBUG_RINGS */
562
563
564 static int sca_xmit(struct sk_buff *skb, struct net_device *dev)
565 {
566 port_t *port = dev_to_port(dev);
567 card_t *card = port->card;
568 pkt_desc __iomem *desc;
569 u32 buff, len;
570
571 spin_lock_irq(&port->lock);
572
573 desc = desc_address(port, port->txin + 1, 1);
574 BUG_ON(readb(&desc->stat)); /* previous xmit should stop queue */
575
576 #ifdef DEBUG_PKT
577 printk(KERN_DEBUG "%s TX(%i):", dev->name, skb->len);
578 debug_frame(skb);
579 #endif
580
581 desc = desc_address(port, port->txin, 1);
582 buff = buffer_offset(port, port->txin, 1);
583 len = skb->len;
584 memcpy_toio(card->rambase + buff, skb->data, len);
585
586 writew(len, &desc->len);
587 writeb(ST_TX_EOM, &desc->stat);
588 dev->trans_start = jiffies;
589
590 port->txin = (port->txin + 1) % card->tx_ring_buffers;
591 sca_outl(desc_offset(port, port->txin, 1),
592 get_dmac_tx(port) + EDAL, card);
593
594 sca_out(DSR_DE, DSR_TX(port->chan), card); /* Enable TX DMA */
595
596 desc = desc_address(port, port->txin + 1, 1);
597 if (readb(&desc->stat)) /* allow 1 packet gap */
598 netif_stop_queue(dev);
599
600 spin_unlock_irq(&port->lock);
601
602 dev_kfree_skb(skb);
603 return 0;
604 }
605
606
607 static u32 __devinit sca_detect_ram(card_t *card, u8 __iomem *rambase,
608 u32 ramsize)
609 {
610 /* Round RAM size to 32 bits, fill from end to start */
611 u32 i = ramsize &= ~3;
612
613 do {
614 i -= 4;
615 writel(i ^ 0x12345678, rambase + i);
616 } while (i > 0);
617
618 for (i = 0; i < ramsize ; i += 4) {
619 if (readl(rambase + i) != (i ^ 0x12345678))
620 break;
621 }
622
623 return i;
624 }
625
626
627 static void __devinit sca_init(card_t *card, int wait_states)
628 {
629 sca_out(wait_states, WCRL, card); /* Wait Control */
630 sca_out(wait_states, WCRM, card);
631 sca_out(wait_states, WCRH, card);
632
633 sca_out(0, DMER, card); /* DMA Master disable */
634 sca_out(0x03, PCR, card); /* DMA priority */
635 sca_out(0, DSR_RX(0), card); /* DMA disable - to halt state */
636 sca_out(0, DSR_TX(0), card);
637 sca_out(0, DSR_RX(1), card);
638 sca_out(0, DSR_TX(1), card);
639 sca_out(DMER_DME, DMER, card); /* DMA Master enable */
640 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree