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v3.5.6
  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/string.h>
 41#include <linux/types.h>
 42#include <asm/io.h>
 43#include <asm/uaccess.h>
 44#include "hd64572.h"
 45
 46#define NAPI_WEIGHT		16
 47
 48#define get_msci(port)	  (port->chan ?   MSCI1_OFFSET :   MSCI0_OFFSET)
 49#define get_dmac_rx(port) (port->chan ? DMAC1RX_OFFSET : DMAC0RX_OFFSET)
 50#define get_dmac_tx(port) (port->chan ? DMAC1TX_OFFSET : DMAC0TX_OFFSET)
 51
 52#define sca_in(reg, card)	     readb(card->scabase + (reg))
 53#define sca_out(value, reg, card)    writeb(value, card->scabase + (reg))
 54#define sca_inw(reg, card)	     readw(card->scabase + (reg))
 55#define sca_outw(value, reg, card)   writew(value, card->scabase + (reg))
 56#define sca_inl(reg, card)	     readl(card->scabase + (reg))
 57#define sca_outl(value, reg, card)   writel(value, card->scabase + (reg))
 58
 59static int sca_poll(struct napi_struct *napi, int budget);
 60
 61static inline port_t* dev_to_port(struct net_device *dev)
 62{
 63	return dev_to_hdlc(dev)->priv;
 64}
 65
 66static inline void enable_intr(port_t *port)
 67{
 68	/* enable DMIB and MSCI RXINTA interrupts */
 69	sca_outl(sca_inl(IER0, port->card) |
 70		 (port->chan ? 0x08002200 : 0x00080022), IER0, port->card);
 71}
 72
 73static inline void disable_intr(port_t *port)
 74{
 75	sca_outl(sca_inl(IER0, port->card) &
 76		 (port->chan ? 0x00FF00FF : 0xFF00FF00), IER0, port->card);
 77}
 78
 79static inline u16 desc_abs_number(port_t *port, u16 desc, int transmit)
 80{
 81	u16 rx_buffs = port->card->rx_ring_buffers;
 82	u16 tx_buffs = port->card->tx_ring_buffers;
 83
 84	desc %= (transmit ? tx_buffs : rx_buffs); // called with "X + 1" etc.
 85	return port->chan * (rx_buffs + tx_buffs) + transmit * rx_buffs + desc;
 86}
 87
 88
 89static inline u16 desc_offset(port_t *port, u16 desc, int transmit)
 90{
 91	/* Descriptor offset always fits in 16 bits */
 92	return desc_abs_number(port, desc, transmit) * sizeof(pkt_desc);
 93}
 94
 95
 96static inline pkt_desc __iomem *desc_address(port_t *port, u16 desc,
 97					     int transmit)
 98{
 99	return (pkt_desc __iomem *)(port->card->rambase +
100				    desc_offset(port, desc, transmit));
101}
102
103
104static inline u32 buffer_offset(port_t *port, u16 desc, int transmit)
105{
106	return port->card->buff_offset +
107		desc_abs_number(port, desc, transmit) * (u32)HDLC_MAX_MRU;
108}
109
110
111static inline void sca_set_carrier(port_t *port)
112{
113	if (!(sca_in(get_msci(port) + ST3, port->card) & ST3_DCD)) {
114#ifdef DEBUG_LINK
115		printk(KERN_DEBUG "%s: sca_set_carrier on\n",
116		       port->netdev.name);
117#endif
118		netif_carrier_on(port->netdev);
119	} else {
120#ifdef DEBUG_LINK
121		printk(KERN_DEBUG "%s: sca_set_carrier off\n",
122		       port->netdev.name);
123#endif
124		netif_carrier_off(port->netdev);
125	}
126}
127
128
129static void sca_init_port(port_t *port)
130{
131	card_t *card = port->card;
132	u16 dmac_rx = get_dmac_rx(port), dmac_tx = get_dmac_tx(port);
133	int transmit, i;
134
135	port->rxin = 0;
136	port->txin = 0;
137	port->txlast = 0;
138
139	for (transmit = 0; transmit < 2; transmit++) {
140		u16 buffs = transmit ? card->tx_ring_buffers
141			: card->rx_ring_buffers;
142
143		for (i = 0; i < buffs; i++) {
144			pkt_desc __iomem *desc = desc_address(port, i, transmit);
145			u16 chain_off = desc_offset(port, i + 1, transmit);
146			u32 buff_off = buffer_offset(port, i, transmit);
147
148			writel(chain_off, &desc->cp);
149			writel(buff_off, &desc->bp);
150			writew(0, &desc->len);
151			writeb(0, &desc->stat);
152		}
153	}
154
155	/* DMA disable - to halt state */
156	sca_out(0, DSR_RX(port->chan), card);
157	sca_out(0, DSR_TX(port->chan), card);
158
159	/* software ABORT - to initial state */
160	sca_out(DCR_ABORT, DCR_RX(port->chan), card);
161	sca_out(DCR_ABORT, DCR_TX(port->chan), card);
162
163	/* current desc addr */
164	sca_outl(desc_offset(port, 0, 0), dmac_rx + CDAL, card);
165	sca_outl(desc_offset(port, card->tx_ring_buffers - 1, 0),
166		 dmac_rx + EDAL, card);
167	sca_outl(desc_offset(port, 0, 1), dmac_tx + CDAL, card);
168	sca_outl(desc_offset(port, 0, 1), dmac_tx + EDAL, card);
169
170	/* clear frame end interrupt counter */
171	sca_out(DCR_CLEAR_EOF, DCR_RX(port->chan), card);
172	sca_out(DCR_CLEAR_EOF, DCR_TX(port->chan), card);
173
174	/* Receive */
175	sca_outw(HDLC_MAX_MRU, dmac_rx + BFLL, card); /* set buffer length */
176	sca_out(0x14, DMR_RX(port->chan), card); /* Chain mode, Multi-frame */
177	sca_out(DIR_EOME, DIR_RX(port->chan), card); /* enable interrupts */
178	sca_out(DSR_DE, DSR_RX(port->chan), card); /* DMA enable */
179
180	/* Transmit */
181	sca_out(0x14, DMR_TX(port->chan), card); /* Chain mode, Multi-frame */
182	sca_out(DIR_EOME, DIR_TX(port->chan), card); /* enable interrupts */
183
184	sca_set_carrier(port);
185	netif_napi_add(port->netdev, &port->napi, sca_poll, NAPI_WEIGHT);
186}
187
188
189/* MSCI interrupt service */
190static inline void sca_msci_intr(port_t *port)
191{
192	u16 msci = get_msci(port);
193	card_t* card = port->card;
194
195	if (sca_in(msci + ST1, card) & ST1_CDCD) {
196		/* Reset MSCI CDCD status bit */
197		sca_out(ST1_CDCD, msci + ST1, card);
198		sca_set_carrier(port);
199	}
200}
201
202
203static inline void sca_rx(card_t *card, port_t *port, pkt_desc __iomem *desc,
204			  u16 rxin)
205{
206	struct net_device *dev = port->netdev;
207	struct sk_buff *skb;
208	u16 len;
209	u32 buff;
210
211	len = readw(&desc->len);
212	skb = dev_alloc_skb(len);
213	if (!skb) {
214		dev->stats.rx_dropped++;
215		return;
216	}
217
218	buff = buffer_offset(port, rxin, 0);
219	memcpy_fromio(skb->data, card->rambase + buff, len);
220
221	skb_put(skb, len);
222#ifdef DEBUG_PKT
223	printk(KERN_DEBUG "%s RX(%i):", dev->name, skb->len);
224	debug_frame(skb);
225#endif
226	dev->stats.rx_packets++;
227	dev->stats.rx_bytes += skb->len;
228	skb->protocol = hdlc_type_trans(skb, dev);
229	netif_receive_skb(skb);
230}
231
232
233/* Receive DMA service */
234static inline int sca_rx_done(port_t *port, int budget)
235{
236	struct net_device *dev = port->netdev;
237	u16 dmac = get_dmac_rx(port);
238	card_t *card = port->card;
239	u8 stat = sca_in(DSR_RX(port->chan), card); /* read DMA Status */
240	int received = 0;
241
242	/* Reset DSR status bits */
243	sca_out((stat & (DSR_EOT | DSR_EOM | DSR_BOF | DSR_COF)) | DSR_DWE,
244		DSR_RX(port->chan), card);
245
246	if (stat & DSR_BOF)
247		/* Dropped one or more frames */
248		dev->stats.rx_over_errors++;
249
250	while (received < budget) {
251		u32 desc_off = desc_offset(port, port->rxin, 0);
252		pkt_desc __iomem *desc;
253		u32 cda = sca_inl(dmac + CDAL, card);
254
255		if ((cda >= desc_off) && (cda < desc_off + sizeof(pkt_desc)))
256			break;	/* No frame received */
257
258		desc = desc_address(port, port->rxin, 0);
259		stat = readb(&desc->stat);
260		if (!(stat & ST_RX_EOM))
261			port->rxpart = 1; /* partial frame received */
262		else if ((stat & ST_ERROR_MASK) || port->rxpart) {
263			dev->stats.rx_errors++;
264			if (stat & ST_RX_OVERRUN)
265				dev->stats.rx_fifo_errors++;
266			else if ((stat & (ST_RX_SHORT | ST_RX_ABORT |
267					  ST_RX_RESBIT)) || port->rxpart)
268				dev->stats.rx_frame_errors++;
269			else if (stat & ST_RX_CRC)
270				dev->stats.rx_crc_errors++;
271			if (stat & ST_RX_EOM)
272				port->rxpart = 0; /* received last fragment */
273		} else {
274			sca_rx(card, port, desc, port->rxin);
275			received++;
276		}
277
278		/* Set new error descriptor address */
279		sca_outl(desc_off, dmac + EDAL, card);
280		port->rxin = (port->rxin + 1) % card->rx_ring_buffers;
281	}
282
283	/* make sure RX DMA is enabled */
284	sca_out(DSR_DE, DSR_RX(port->chan), card);
285	return received;
286}
287
288
289/* Transmit DMA service */
290static inline void sca_tx_done(port_t *port)
291{
292	struct net_device *dev = port->netdev;
293	card_t* card = port->card;
294	u8 stat;
295	unsigned count = 0;
296
297	spin_lock(&port->lock);
298
299	stat = sca_in(DSR_TX(port->chan), card); /* read DMA Status */
300
301	/* Reset DSR status bits */
302	sca_out((stat & (DSR_EOT | DSR_EOM | DSR_BOF | DSR_COF)) | DSR_DWE,
303		DSR_TX(port->chan), card);
304
305	while (1) {
306		pkt_desc __iomem *desc = desc_address(port, port->txlast, 1);
307		u8 stat = readb(&desc->stat);
308
309		if (!(stat & ST_TX_OWNRSHP))
310			break; /* not yet transmitted */
311		if (stat & ST_TX_UNDRRUN) {
312			dev->stats.tx_errors++;
313			dev->stats.tx_fifo_errors++;
314		} else {
315			dev->stats.tx_packets++;
316			dev->stats.tx_bytes += readw(&desc->len);
317		}
318		writeb(0, &desc->stat);	/* Free descriptor */
319		count++;
320		port->txlast = (port->txlast + 1) % card->tx_ring_buffers;
321	}
322
323	if (count)
324		netif_wake_queue(dev);
325	spin_unlock(&port->lock);
326}
327
328
329static int sca_poll(struct napi_struct *napi, int budget)
330{
331	port_t *port = container_of(napi, port_t, napi);
332	u32 isr0 = sca_inl(ISR0, port->card);
333	int received = 0;
334
335	if (isr0 & (port->chan ? 0x08000000 : 0x00080000))
336		sca_msci_intr(port);
337
338	if (isr0 & (port->chan ? 0x00002000 : 0x00000020))
339		sca_tx_done(port);
340
341	if (isr0 & (port->chan ? 0x00000200 : 0x00000002))
342		received = sca_rx_done(port, budget);
343
344	if (received < budget) {
345		napi_complete(napi);
346		enable_intr(port);
347	}
348
349	return received;
350}
351
352static irqreturn_t sca_intr(int irq, void *dev_id)
353{
354	card_t *card = dev_id;
355	u32 isr0 = sca_inl(ISR0, card);
356	int i, handled = 0;
357
358	for (i = 0; i < 2; i++) {
359		port_t *port = get_port(card, i);
360		if (port && (isr0 & (i ? 0x08002200 : 0x00080022))) {
361			handled = 1;
362			disable_intr(port);
363			napi_schedule(&port->napi);
364		}
365	}
366
367	return IRQ_RETVAL(handled);
368}
369
370
371static void sca_set_port(port_t *port)
372{
373	card_t* card = port->card;
374	u16 msci = get_msci(port);
375	u8 md2 = sca_in(msci + MD2, card);
376	unsigned int tmc, br = 10, brv = 1024;
377
378
379	if (port->settings.clock_rate > 0) {
380		/* Try lower br for better accuracy*/
381		do {
382			br--;
383			brv >>= 1; /* brv = 2^9 = 512 max in specs */
384
385			/* Baud Rate = CLOCK_BASE / TMC / 2^BR */
386			tmc = CLOCK_BASE / brv / port->settings.clock_rate;
387		}while (br > 1 && tmc <= 128);
388
389		if (tmc < 1) {
390			tmc = 1;
391			br = 0;	/* For baud=CLOCK_BASE we use tmc=1 br=0 */
392			brv = 1;
393		} else if (tmc > 255)
394			tmc = 256; /* tmc=0 means 256 - low baud rates */
395
396		port->settings.clock_rate = CLOCK_BASE / brv / tmc;
397	} else {
398		br = 9; /* Minimum clock rate */
399		tmc = 256;	/* 8bit = 0 */
400		port->settings.clock_rate = CLOCK_BASE / (256 * 512);
401	}
402
403	port->rxs = (port->rxs & ~CLK_BRG_MASK) | br;
404	port->txs = (port->txs & ~CLK_BRG_MASK) | br;
405	port->tmc = tmc;
406
407	/* baud divisor - time constant*/
408	sca_out(port->tmc, msci + TMCR, card);
409	sca_out(port->tmc, msci + TMCT, card);
410
411	/* Set BRG bits */
412	sca_out(port->rxs, msci + RXS, card);
413	sca_out(port->txs, msci + TXS, card);
414
415	if (port->settings.loopback)
416		md2 |= MD2_LOOPBACK;
417	else
418		md2 &= ~MD2_LOOPBACK;
419
420	sca_out(md2, msci + MD2, card);
421
422}
423
424
425static void sca_open(struct net_device *dev)
426{
427	port_t *port = dev_to_port(dev);
428	card_t* card = port->card;
429	u16 msci = get_msci(port);
430	u8 md0, md2;
431
432	switch(port->encoding) {
433	case ENCODING_NRZ:	md2 = MD2_NRZ;		break;
434	case ENCODING_NRZI:	md2 = MD2_NRZI;		break;
435	case ENCODING_FM_MARK:	md2 = MD2_FM_MARK;	break;
436	case ENCODING_FM_SPACE:	md2 = MD2_FM_SPACE;	break;
437	default:		md2 = MD2_MANCHESTER;
438	}
439
440	if (port->settings.loopback)
441		md2 |= MD2_LOOPBACK;
442
443	switch(port->parity) {
444	case PARITY_CRC16_PR0:	     md0 = MD0_HDLC | MD0_CRC_16_0;  break;
445	case PARITY_CRC16_PR1:	     md0 = MD0_HDLC | MD0_CRC_16;    break;
446	case PARITY_CRC32_PR1_CCITT: md0 = MD0_HDLC | MD0_CRC_ITU32; break;
447	case PARITY_CRC16_PR1_CCITT: md0 = MD0_HDLC | MD0_CRC_ITU;   break;
448	default:		     md0 = MD0_HDLC | MD0_CRC_NONE;
449	}
450
451	sca_out(CMD_RESET, msci + CMD, card);
452	sca_out(md0, msci + MD0, card);
453	sca_out(0x00, msci + MD1, card); /* no address field check */
454	sca_out(md2, msci + MD2, card);
455	sca_out(0x7E, msci + IDL, card); /* flag character 0x7E */
456	/* Skip the rest of underrun frame */
457	sca_out(CTL_IDLE | CTL_URCT | CTL_URSKP, msci + CTL, card);
458	sca_out(0x0F, msci + RNR, card); /* +1=RX DMA activation condition */
459	sca_out(0x3C, msci + TFS, card); /* +1 = TX start */
460	sca_out(0x38, msci + TCR, card); /* =Critical TX DMA activ condition */
461	sca_out(0x38, msci + TNR0, card); /* =TX DMA activation condition */
462	sca_out(0x3F, msci + TNR1, card); /* +1=TX DMA deactivation condition*/
463
464/* We're using the following interrupts:
465   - RXINTA (DCD changes only)
466   - DMIB (EOM - single frame transfer complete)
467*/
468	sca_outl(IE0_RXINTA | IE0_CDCD, msci + IE0, card);
469
470	sca_out(port->tmc, msci + TMCR, card);
471	sca_out(port->tmc, msci + TMCT, card);
472	sca_out(port->rxs, msci + RXS, card);
473	sca_out(port->txs, msci + TXS, card);
474	sca_out(CMD_TX_ENABLE, msci + CMD, card);
475	sca_out(CMD_RX_ENABLE, msci + CMD, card);
476
477	sca_set_carrier(port);
478	enable_intr(port);
479	napi_enable(&port->napi);
480	netif_start_queue(dev);
481}
482
483
484static void sca_close(struct net_device *dev)
485{
486	port_t *port = dev_to_port(dev);
487
488	/* reset channel */
489	sca_out(CMD_RESET, get_msci(port) + CMD, port->card);
490	disable_intr(port);
491	napi_disable(&port->napi);
492	netif_stop_queue(dev);
493}
494
495
496static int sca_attach(struct net_device *dev, unsigned short encoding,
497		      unsigned short parity)
498{
499	if (encoding != ENCODING_NRZ &&
500	    encoding != ENCODING_NRZI &&
501	    encoding != ENCODING_FM_MARK &&
502	    encoding != ENCODING_FM_SPACE &&
503	    encoding != ENCODING_MANCHESTER)
504		return -EINVAL;
505
506	if (parity != PARITY_NONE &&
507	    parity != PARITY_CRC16_PR0 &&
508	    parity != PARITY_CRC16_PR1 &&
509	    parity != PARITY_CRC32_PR1_CCITT &&
510	    parity != PARITY_CRC16_PR1_CCITT)
511		return -EINVAL;
512
513	dev_to_port(dev)->encoding = encoding;
514	dev_to_port(dev)->parity = parity;
515	return 0;
516}
517
518
519#ifdef DEBUG_RINGS
520static void sca_dump_rings(struct net_device *dev)
521{
522	port_t *port = dev_to_port(dev);
523	card_t *card = port->card;
524	u16 cnt;
525
526	printk(KERN_DEBUG "RX ring: CDA=%u EDA=%u DSR=%02X in=%u %sactive",
527	       sca_inl(get_dmac_rx(port) + CDAL, card),
528	       sca_inl(get_dmac_rx(port) + EDAL, card),
529	       sca_in(DSR_RX(port->chan), card), port->rxin,
530	       sca_in(DSR_RX(port->chan), card) & DSR_DE ? "" : "in");
531	for (cnt = 0; cnt < port->card->rx_ring_buffers; cnt++)
532		pr_cont(" %02X", readb(&(desc_address(port, cnt, 0)->stat)));
533	pr_cont("\n");
534
535	printk(KERN_DEBUG "TX ring: CDA=%u EDA=%u DSR=%02X in=%u "
536	       "last=%u %sactive",
537	       sca_inl(get_dmac_tx(port) + CDAL, card),
538	       sca_inl(get_dmac_tx(port) + EDAL, card),
539	       sca_in(DSR_TX(port->chan), card), port->txin, port->txlast,
540	       sca_in(DSR_TX(port->chan), card) & DSR_DE ? "" : "in");
541
542	for (cnt = 0; cnt < port->card->tx_ring_buffers; cnt++)
543		pr_cont(" %02X", readb(&(desc_address(port, cnt, 1)->stat)));
544	pr_cont("\n");
545
546	printk(KERN_DEBUG "MSCI: MD: %02x %02x %02x,"
547	       " ST: %02x %02x %02x %02x %02x, FST: %02x CST: %02x %02x\n",
548	       sca_in(get_msci(port) + MD0, card),
549	       sca_in(get_msci(port) + MD1, card),
550	       sca_in(get_msci(port) + MD2, card),
551	       sca_in(get_msci(port) + ST0, card),
552	       sca_in(get_msci(port) + ST1, card),
553	       sca_in(get_msci(port) + ST2, card),
554	       sca_in(get_msci(port) + ST3, card),
555	       sca_in(get_msci(port) + ST4, card),
556	       sca_in(get_msci(port) + FST, card),
557	       sca_in(get_msci(port) + CST0, card),
558	       sca_in(get_msci(port) + CST1, card));
559
560	printk(KERN_DEBUG "ILAR: %02x ISR: %08x %08x\n", sca_in(ILAR, card),
561	       sca_inl(ISR0, card), sca_inl(ISR1, card));
562}
563#endif /* DEBUG_RINGS */
564
565
566static netdev_tx_t sca_xmit(struct sk_buff *skb, struct net_device *dev)
567{
568	port_t *port = dev_to_port(dev);
569	card_t *card = port->card;
570	pkt_desc __iomem *desc;
571	u32 buff, len;
572
573	spin_lock_irq(&port->lock);
574
575	desc = desc_address(port, port->txin + 1, 1);
576	BUG_ON(readb(&desc->stat)); /* previous xmit should stop queue */
577
578#ifdef DEBUG_PKT
579	printk(KERN_DEBUG "%s TX(%i):", dev->name, skb->len);
580	debug_frame(skb);
581#endif
582
583	desc = desc_address(port, port->txin, 1);
584	buff = buffer_offset(port, port->txin, 1);
585	len = skb->len;
586	memcpy_toio(card->rambase + buff, skb->data, len);
587
588	writew(len, &desc->len);
589	writeb(ST_TX_EOM, &desc->stat);
590
591	port->txin = (port->txin + 1) % card->tx_ring_buffers;
592	sca_outl(desc_offset(port, port->txin, 1),
593		 get_dmac_tx(port) + EDAL, card);
594
595	sca_out(DSR_DE, DSR_TX(port->chan), card); /* Enable TX DMA */
596
597	desc = desc_address(port, port->txin + 1, 1);
598	if (readb(&desc->stat)) /* allow 1 packet gap */
599		netif_stop_queue(dev);
600
601	spin_unlock_irq(&port->lock);
602
603	dev_kfree_skb(skb);
604	return NETDEV_TX_OK;
605}
606
607
608static u32 __devinit sca_detect_ram(card_t *card, u8 __iomem *rambase,
609				    u32 ramsize)
610{
611	/* Round RAM size to 32 bits, fill from end to start */
612	u32 i = ramsize &= ~3;
613
614	do {
615		i -= 4;
616		writel(i ^ 0x12345678, rambase + i);
617	} while (i > 0);
618
619	for (i = 0; i < ramsize ; i += 4) {
620		if (readl(rambase + i) != (i ^ 0x12345678))
621			break;
622	}
623
624	return i;
625}
626
627
628static void __devinit sca_init(card_t *card, int wait_states)
629{
630	sca_out(wait_states, WCRL, card); /* Wait Control */
631	sca_out(wait_states, WCRM, card);
632	sca_out(wait_states, WCRH, card);
633
634	sca_out(0, DMER, card);	/* DMA Master disable */
635	sca_out(0x03, PCR, card); /* DMA priority */
636	sca_out(0, DSR_RX(0), card); /* DMA disable - to halt state */
637	sca_out(0, DSR_TX(0), card);
638	sca_out(0, DSR_RX(1), card);
639	sca_out(0, DSR_TX(1), card);
640	sca_out(DMER_DME, DMER, card); /* DMA Master enable */
641}
v4.17
  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/interrupt.h>
 33#include <linux/ioport.h>
 34#include <linux/jiffies.h>
 35#include <linux/kernel.h>
 36#include <linux/module.h>
 37#include <linux/netdevice.h>
 38#include <linux/skbuff.h>
 39#include <linux/string.h>
 40#include <linux/types.h>
 41#include <asm/io.h>
 42#include <linux/uaccess.h>
 43#include "hd64572.h"
 44
 45#define NAPI_WEIGHT		16
 46
 47#define get_msci(port)	  (port->chan ?   MSCI1_OFFSET :   MSCI0_OFFSET)
 48#define get_dmac_rx(port) (port->chan ? DMAC1RX_OFFSET : DMAC0RX_OFFSET)
 49#define get_dmac_tx(port) (port->chan ? DMAC1TX_OFFSET : DMAC0TX_OFFSET)
 50
 51#define sca_in(reg, card)	     readb(card->scabase + (reg))
 52#define sca_out(value, reg, card)    writeb(value, card->scabase + (reg))
 53#define sca_inw(reg, card)	     readw(card->scabase + (reg))
 54#define sca_outw(value, reg, card)   writew(value, card->scabase + (reg))
 55#define sca_inl(reg, card)	     readl(card->scabase + (reg))
 56#define sca_outl(value, reg, card)   writel(value, card->scabase + (reg))
 57
 58static int sca_poll(struct napi_struct *napi, int budget);
 59
 60static inline port_t* dev_to_port(struct net_device *dev)
 61{
 62	return dev_to_hdlc(dev)->priv;
 63}
 64
 65static inline void enable_intr(port_t *port)
 66{
 67	/* enable DMIB and MSCI RXINTA interrupts */
 68	sca_outl(sca_inl(IER0, port->card) |
 69		 (port->chan ? 0x08002200 : 0x00080022), IER0, port->card);
 70}
 71
 72static inline void disable_intr(port_t *port)
 73{
 74	sca_outl(sca_inl(IER0, port->card) &
 75		 (port->chan ? 0x00FF00FF : 0xFF00FF00), IER0, port->card);
 76}
 77
 78static inline u16 desc_abs_number(port_t *port, u16 desc, int transmit)
 79{
 80	u16 rx_buffs = port->card->rx_ring_buffers;
 81	u16 tx_buffs = port->card->tx_ring_buffers;
 82
 83	desc %= (transmit ? tx_buffs : rx_buffs); // called with "X + 1" etc.
 84	return port->chan * (rx_buffs + tx_buffs) + transmit * rx_buffs + desc;
 85}
 86
 87
 88static inline u16 desc_offset(port_t *port, u16 desc, int transmit)
 89{
 90	/* Descriptor offset always fits in 16 bits */
 91	return desc_abs_number(port, desc, transmit) * sizeof(pkt_desc);
 92}
 93
 94
 95static inline pkt_desc __iomem *desc_address(port_t *port, u16 desc,
 96					     int transmit)
 97{
 98	return (pkt_desc __iomem *)(port->card->rambase +
 99				    desc_offset(port, desc, transmit));
100}
101
102
103static inline u32 buffer_offset(port_t *port, u16 desc, int transmit)
104{
105	return port->card->buff_offset +
106		desc_abs_number(port, desc, transmit) * (u32)HDLC_MAX_MRU;
107}
108
109
110static inline void sca_set_carrier(port_t *port)
111{
112	if (!(sca_in(get_msci(port) + ST3, port->card) & ST3_DCD)) {
113#ifdef DEBUG_LINK
114		printk(KERN_DEBUG "%s: sca_set_carrier on\n",
115		       port->netdev.name);
116#endif
117		netif_carrier_on(port->netdev);
118	} else {
119#ifdef DEBUG_LINK
120		printk(KERN_DEBUG "%s: sca_set_carrier off\n",
121		       port->netdev.name);
122#endif
123		netif_carrier_off(port->netdev);
124	}
125}
126
127
128static void sca_init_port(port_t *port)
129{
130	card_t *card = port->card;
131	u16 dmac_rx = get_dmac_rx(port), dmac_tx = get_dmac_tx(port);
132	int transmit, i;
133
134	port->rxin = 0;
135	port->txin = 0;
136	port->txlast = 0;
137
138	for (transmit = 0; transmit < 2; transmit++) {
139		u16 buffs = transmit ? card->tx_ring_buffers
140			: card->rx_ring_buffers;
141
142		for (i = 0; i < buffs; i++) {
143			pkt_desc __iomem *desc = desc_address(port, i, transmit);
144			u16 chain_off = desc_offset(port, i + 1, transmit);
145			u32 buff_off = buffer_offset(port, i, transmit);
146
147			writel(chain_off, &desc->cp);
148			writel(buff_off, &desc->bp);
149			writew(0, &desc->len);
150			writeb(0, &desc->stat);
151		}
152	}
153
154	/* DMA disable - to halt state */
155	sca_out(0, DSR_RX(port->chan), card);
156	sca_out(0, DSR_TX(port->chan), card);
157
158	/* software ABORT - to initial state */
159	sca_out(DCR_ABORT, DCR_RX(port->chan), card);
160	sca_out(DCR_ABORT, DCR_TX(port->chan), card);
161
162	/* current desc addr */
163	sca_outl(desc_offset(port, 0, 0), dmac_rx + CDAL, card);
164	sca_outl(desc_offset(port, card->tx_ring_buffers - 1, 0),
165		 dmac_rx + EDAL, card);
166	sca_outl(desc_offset(port, 0, 1), dmac_tx + CDAL, card);
167	sca_outl(desc_offset(port, 0, 1), dmac_tx + EDAL, card);
168
169	/* clear frame end interrupt counter */
170	sca_out(DCR_CLEAR_EOF, DCR_RX(port->chan), card);
171	sca_out(DCR_CLEAR_EOF, DCR_TX(port->chan), card);
172
173	/* Receive */
174	sca_outw(HDLC_MAX_MRU, dmac_rx + BFLL, card); /* set buffer length */
175	sca_out(0x14, DMR_RX(port->chan), card); /* Chain mode, Multi-frame */
176	sca_out(DIR_EOME, DIR_RX(port->chan), card); /* enable interrupts */
177	sca_out(DSR_DE, DSR_RX(port->chan), card); /* DMA enable */
178
179	/* Transmit */
180	sca_out(0x14, DMR_TX(port->chan), card); /* Chain mode, Multi-frame */
181	sca_out(DIR_EOME, DIR_TX(port->chan), card); /* enable interrupts */
182
183	sca_set_carrier(port);
184	netif_napi_add(port->netdev, &port->napi, sca_poll, NAPI_WEIGHT);
185}
186
187
188/* MSCI interrupt service */
189static inline void sca_msci_intr(port_t *port)
190{
191	u16 msci = get_msci(port);
192	card_t* card = port->card;
193
194	if (sca_in(msci + ST1, card) & ST1_CDCD) {
195		/* Reset MSCI CDCD status bit */
196		sca_out(ST1_CDCD, msci + ST1, card);
197		sca_set_carrier(port);
198	}
199}
200
201
202static inline void sca_rx(card_t *card, port_t *port, pkt_desc __iomem *desc,
203			  u16 rxin)
204{
205	struct net_device *dev = port->netdev;
206	struct sk_buff *skb;
207	u16 len;
208	u32 buff;
209
210	len = readw(&desc->len);
211	skb = dev_alloc_skb(len);
212	if (!skb) {
213		dev->stats.rx_dropped++;
214		return;
215	}
216
217	buff = buffer_offset(port, rxin, 0);
218	memcpy_fromio(skb->data, card->rambase + buff, len);
219
220	skb_put(skb, len);
221#ifdef DEBUG_PKT
222	printk(KERN_DEBUG "%s RX(%i):", dev->name, skb->len);
223	debug_frame(skb);
224#endif
225	dev->stats.rx_packets++;
226	dev->stats.rx_bytes += skb->len;
227	skb->protocol = hdlc_type_trans(skb, dev);
228	netif_receive_skb(skb);
229}
230
231
232/* Receive DMA service */
233static inline int sca_rx_done(port_t *port, int budget)
234{
235	struct net_device *dev = port->netdev;
236	u16 dmac = get_dmac_rx(port);
237	card_t *card = port->card;
238	u8 stat = sca_in(DSR_RX(port->chan), card); /* read DMA Status */
239	int received = 0;
240
241	/* Reset DSR status bits */
242	sca_out((stat & (DSR_EOT | DSR_EOM | DSR_BOF | DSR_COF)) | DSR_DWE,
243		DSR_RX(port->chan), card);
244
245	if (stat & DSR_BOF)
246		/* Dropped one or more frames */
247		dev->stats.rx_over_errors++;
248
249	while (received < budget) {
250		u32 desc_off = desc_offset(port, port->rxin, 0);
251		pkt_desc __iomem *desc;
252		u32 cda = sca_inl(dmac + CDAL, card);
253
254		if ((cda >= desc_off) && (cda < desc_off + sizeof(pkt_desc)))
255			break;	/* No frame received */
256
257		desc = desc_address(port, port->rxin, 0);
258		stat = readb(&desc->stat);
259		if (!(stat & ST_RX_EOM))
260			port->rxpart = 1; /* partial frame received */
261		else if ((stat & ST_ERROR_MASK) || port->rxpart) {
262			dev->stats.rx_errors++;
263			if (stat & ST_RX_OVERRUN)
264				dev->stats.rx_fifo_errors++;
265			else if ((stat & (ST_RX_SHORT | ST_RX_ABORT |
266					  ST_RX_RESBIT)) || port->rxpart)
267				dev->stats.rx_frame_errors++;
268			else if (stat & ST_RX_CRC)
269				dev->stats.rx_crc_errors++;
270			if (stat & ST_RX_EOM)
271				port->rxpart = 0; /* received last fragment */
272		} else {
273			sca_rx(card, port, desc, port->rxin);
274			received++;
275		}
276
277		/* Set new error descriptor address */
278		sca_outl(desc_off, dmac + EDAL, card);
279		port->rxin = (port->rxin + 1) % card->rx_ring_buffers;
280	}
281
282	/* make sure RX DMA is enabled */
283	sca_out(DSR_DE, DSR_RX(port->chan), card);
284	return received;
285}
286
287
288/* Transmit DMA service */
289static inline void sca_tx_done(port_t *port)
290{
291	struct net_device *dev = port->netdev;
292	card_t* card = port->card;
293	u8 stat;
294	unsigned count = 0;
295
296	spin_lock(&port->lock);
297
298	stat = sca_in(DSR_TX(port->chan), card); /* read DMA Status */
299
300	/* Reset DSR status bits */
301	sca_out((stat & (DSR_EOT | DSR_EOM | DSR_BOF | DSR_COF)) | DSR_DWE,
302		DSR_TX(port->chan), card);
303
304	while (1) {
305		pkt_desc __iomem *desc = desc_address(port, port->txlast, 1);
306		u8 stat = readb(&desc->stat);
307
308		if (!(stat & ST_TX_OWNRSHP))
309			break; /* not yet transmitted */
310		if (stat & ST_TX_UNDRRUN) {
311			dev->stats.tx_errors++;
312			dev->stats.tx_fifo_errors++;
313		} else {
314			dev->stats.tx_packets++;
315			dev->stats.tx_bytes += readw(&desc->len);
316		}
317		writeb(0, &desc->stat);	/* Free descriptor */
318		count++;
319		port->txlast = (port->txlast + 1) % card->tx_ring_buffers;
320	}
321
322	if (count)
323		netif_wake_queue(dev);
324	spin_unlock(&port->lock);
325}
326
327
328static 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_done(napi, received);
345		enable_intr(port);
346	}
347
348	return received;
349}
350
351static 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
370static 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
424static 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
483static 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
495static 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
519static 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		pr_cont(" %02X", readb(&(desc_address(port, cnt, 0)->stat)));
532	pr_cont("\n");
533
534	printk(KERN_DEBUG "TX ring: CDA=%u EDA=%u DSR=%02X in=%u "
535	       "last=%u %sactive",
536	       sca_inl(get_dmac_tx(port) + CDAL, card),
537	       sca_inl(get_dmac_tx(port) + EDAL, card),
538	       sca_in(DSR_TX(port->chan), card), port->txin, port->txlast,
539	       sca_in(DSR_TX(port->chan), card) & DSR_DE ? "" : "in");
540
541	for (cnt = 0; cnt < port->card->tx_ring_buffers; cnt++)
542		pr_cont(" %02X", readb(&(desc_address(port, cnt, 1)->stat)));
543	pr_cont("\n");
544
545	printk(KERN_DEBUG "MSCI: MD: %02x %02x %02x,"
546	       " ST: %02x %02x %02x %02x %02x, FST: %02x CST: %02x %02x\n",
547	       sca_in(get_msci(port) + MD0, card),
548	       sca_in(get_msci(port) + MD1, card),
549	       sca_in(get_msci(port) + MD2, card),
550	       sca_in(get_msci(port) + ST0, card),
551	       sca_in(get_msci(port) + ST1, card),
552	       sca_in(get_msci(port) + ST2, card),
553	       sca_in(get_msci(port) + ST3, card),
554	       sca_in(get_msci(port) + ST4, card),
555	       sca_in(get_msci(port) + FST, card),
556	       sca_in(get_msci(port) + CST0, card),
557	       sca_in(get_msci(port) + CST1, card));
558
559	printk(KERN_DEBUG "ILAR: %02x ISR: %08x %08x\n", sca_in(ILAR, card),
560	       sca_inl(ISR0, card), sca_inl(ISR1, card));
561}
562#endif /* DEBUG_RINGS */
563
564
565static netdev_tx_t sca_xmit(struct sk_buff *skb, struct net_device *dev)
566{
567	port_t *port = dev_to_port(dev);
568	card_t *card = port->card;
569	pkt_desc __iomem *desc;
570	u32 buff, len;
571
572	spin_lock_irq(&port->lock);
573
574	desc = desc_address(port, port->txin + 1, 1);
575	BUG_ON(readb(&desc->stat)); /* previous xmit should stop queue */
576
577#ifdef DEBUG_PKT
578	printk(KERN_DEBUG "%s TX(%i):", dev->name, skb->len);
579	debug_frame(skb);
580#endif
581
582	desc = desc_address(port, port->txin, 1);
583	buff = buffer_offset(port, port->txin, 1);
584	len = skb->len;
585	memcpy_toio(card->rambase + buff, skb->data, len);
586
587	writew(len, &desc->len);
588	writeb(ST_TX_EOM, &desc->stat);
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 NETDEV_TX_OK;
604}
605
606
607static u32 sca_detect_ram(card_t *card, u8 __iomem *rambase, u32 ramsize)
 
608{
609	/* Round RAM size to 32 bits, fill from end to start */
610	u32 i = ramsize &= ~3;
611
612	do {
613		i -= 4;
614		writel(i ^ 0x12345678, rambase + i);
615	} while (i > 0);
616
617	for (i = 0; i < ramsize ; i += 4) {
618		if (readl(rambase + i) != (i ^ 0x12345678))
619			break;
620	}
621
622	return i;
623}
624
625
626static void sca_init(card_t *card, int wait_states)
627{
628	sca_out(wait_states, WCRL, card); /* Wait Control */
629	sca_out(wait_states, WCRM, card);
630	sca_out(wait_states, WCRH, card);
631
632	sca_out(0, DMER, card);	/* DMA Master disable */
633	sca_out(0x03, PCR, card); /* DMA priority */
634	sca_out(0, DSR_RX(0), card); /* DMA disable - to halt state */
635	sca_out(0, DSR_TX(0), card);
636	sca_out(0, DSR_RX(1), card);
637	sca_out(0, DSR_TX(1), card);
638	sca_out(DMER_DME, DMER, card); /* DMA Master enable */
639}