1 // SPDX-License-Identifier: GPL-2.0-only
3 * Hitachi (now Renesas) SCA-II HD64572 driver for Linux
5 * Copyright (C) 1998-2008 Krzysztof Halasa <khc@pm.waw.pl>
7 * Source of information: HD64572 SCA-II User's Manual
9 * We use the following SCA memory map:
11 * Packet buffer descriptor rings - starting from card->rambase:
12 * rx_ring_buffers * sizeof(pkt_desc) = logical channel #0 RX ring
13 * tx_ring_buffers * sizeof(pkt_desc) = logical channel #0 TX ring
14 * rx_ring_buffers * sizeof(pkt_desc) = logical channel #1 RX ring (if used)
15 * tx_ring_buffers * sizeof(pkt_desc) = logical channel #1 TX ring (if used)
17 * Packet data buffers - starting from card->rambase + buff_offset:
18 * rx_ring_buffers * HDLC_MAX_MRU = logical channel #0 RX buffers
19 * tx_ring_buffers * HDLC_MAX_MRU = logical channel #0 TX buffers
20 * rx_ring_buffers * HDLC_MAX_MRU = logical channel #0 RX buffers (if used)
21 * tx_ring_buffers * HDLC_MAX_MRU = logical channel #0 TX buffers (if used)
24 #include <linux/bitops.h>
25 #include <linux/errno.h>
26 #include <linux/fcntl.h>
27 #include <linux/hdlc.h>
29 #include <linux/interrupt.h>
30 #include <linux/ioport.h>
31 #include <linux/jiffies.h>
32 #include <linux/kernel.h>
33 #include <linux/module.h>
34 #include <linux/netdevice.h>
35 #include <linux/skbuff.h>
36 #include <linux/string.h>
37 #include <linux/types.h>
39 #include <linux/uaccess.h>
42 #define NAPI_WEIGHT 16
44 #define get_msci(port) ((port)->chan ? MSCI1_OFFSET : MSCI0_OFFSET)
45 #define get_dmac_rx(port) ((port)->chan ? DMAC1RX_OFFSET : DMAC0RX_OFFSET)
46 #define get_dmac_tx(port) ((port)->chan ? DMAC1TX_OFFSET : DMAC0TX_OFFSET)
48 #define sca_in(reg, card) readb((card)->scabase + (reg))
49 #define sca_out(value, reg, card) writeb(value, (card)->scabase + (reg))
50 #define sca_inw(reg, card) readw((card)->scabase + (reg))
51 #define sca_outw(value, reg, card) writew(value, (card)->scabase + (reg))
52 #define sca_inl(reg, card) readl((card)->scabase + (reg))
53 #define sca_outl(value, reg, card) writel(value, (card)->scabase + (reg))
55 static int sca_poll(struct napi_struct *napi, int budget);
57 static inline port_t *dev_to_port(struct net_device *dev)
59 return dev_to_hdlc(dev)->priv;
62 static inline void enable_intr(port_t *port)
64 /* enable DMIB and MSCI RXINTA interrupts */
65 sca_outl(sca_inl(IER0, port->card) |
66 (port->chan ? 0x08002200 : 0x00080022), IER0, port->card);
69 static inline void disable_intr(port_t *port)
71 sca_outl(sca_inl(IER0, port->card) &
72 (port->chan ? 0x00FF00FF : 0xFF00FF00), IER0, port->card);
75 static inline u16 desc_abs_number(port_t *port, u16 desc, int transmit)
77 u16 rx_buffs = port->card->rx_ring_buffers;
78 u16 tx_buffs = port->card->tx_ring_buffers;
80 desc %= (transmit ? tx_buffs : rx_buffs); // called with "X + 1" etc.
81 return port->chan * (rx_buffs + tx_buffs) + transmit * rx_buffs + desc;
84 static inline u16 desc_offset(port_t *port, u16 desc, int transmit)
86 /* Descriptor offset always fits in 16 bits */
87 return desc_abs_number(port, desc, transmit) * sizeof(pkt_desc);
90 static inline pkt_desc __iomem *desc_address(port_t *port, u16 desc,
93 return (pkt_desc __iomem *)(port->card->rambase +
94 desc_offset(port, desc, transmit));
97 static inline u32 buffer_offset(port_t *port, u16 desc, int transmit)
99 return port->card->buff_offset +
100 desc_abs_number(port, desc, transmit) * (u32)HDLC_MAX_MRU;
103 static inline void sca_set_carrier(port_t *port)
105 if (!(sca_in(get_msci(port) + ST3, port->card) & ST3_DCD)) {
107 printk(KERN_DEBUG "%s: sca_set_carrier on\n",
110 netif_carrier_on(port->netdev);
113 printk(KERN_DEBUG "%s: sca_set_carrier off\n",
116 netif_carrier_off(port->netdev);
120 static void sca_init_port(port_t *port)
122 card_t *card = port->card;
123 u16 dmac_rx = get_dmac_rx(port), dmac_tx = get_dmac_tx(port);
130 for (transmit = 0; transmit < 2; transmit++) {
131 u16 buffs = transmit ? card->tx_ring_buffers
132 : card->rx_ring_buffers;
134 for (i = 0; i < buffs; i++) {
135 pkt_desc __iomem *desc = desc_address(port, i, transmit);
136 u16 chain_off = desc_offset(port, i + 1, transmit);
137 u32 buff_off = buffer_offset(port, i, transmit);
139 writel(chain_off, &desc->cp);
140 writel(buff_off, &desc->bp);
141 writew(0, &desc->len);
142 writeb(0, &desc->stat);
146 /* DMA disable - to halt state */
147 sca_out(0, DSR_RX(port->chan), card);
148 sca_out(0, DSR_TX(port->chan), card);
150 /* software ABORT - to initial state */
151 sca_out(DCR_ABORT, DCR_RX(port->chan), card);
152 sca_out(DCR_ABORT, DCR_TX(port->chan), card);
154 /* current desc addr */
155 sca_outl(desc_offset(port, 0, 0), dmac_rx + CDAL, card);
156 sca_outl(desc_offset(port, card->tx_ring_buffers - 1, 0),
157 dmac_rx + EDAL, card);
158 sca_outl(desc_offset(port, 0, 1), dmac_tx + CDAL, card);
159 sca_outl(desc_offset(port, 0, 1), dmac_tx + EDAL, card);
161 /* clear frame end interrupt counter */
162 sca_out(DCR_CLEAR_EOF, DCR_RX(port->chan), card);
163 sca_out(DCR_CLEAR_EOF, DCR_TX(port->chan), card);
166 sca_outw(HDLC_MAX_MRU, dmac_rx + BFLL, card); /* set buffer length */
167 sca_out(0x14, DMR_RX(port->chan), card); /* Chain mode, Multi-frame */
168 sca_out(DIR_EOME, DIR_RX(port->chan), card); /* enable interrupts */
169 sca_out(DSR_DE, DSR_RX(port->chan), card); /* DMA enable */
172 sca_out(0x14, DMR_TX(port->chan), card); /* Chain mode, Multi-frame */
173 sca_out(DIR_EOME, DIR_TX(port->chan), card); /* enable interrupts */
175 sca_set_carrier(port);
176 netif_napi_add(port->netdev, &port->napi, sca_poll, NAPI_WEIGHT);
179 /* MSCI interrupt service */
180 static inline void sca_msci_intr(port_t *port)
182 u16 msci = get_msci(port);
183 card_t *card = port->card;
185 if (sca_in(msci + ST1, card) & ST1_CDCD) {
186 /* Reset MSCI CDCD status bit */
187 sca_out(ST1_CDCD, msci + ST1, card);
188 sca_set_carrier(port);
192 static inline void sca_rx(card_t *card, port_t *port, pkt_desc __iomem *desc,
195 struct net_device *dev = port->netdev;
200 len = readw(&desc->len);
201 skb = dev_alloc_skb(len);
203 dev->stats.rx_dropped++;
207 buff = buffer_offset(port, rxin, 0);
208 memcpy_fromio(skb->data, card->rambase + buff, len);
212 printk(KERN_DEBUG "%s RX(%i):", dev->name, skb->len);
215 dev->stats.rx_packets++;
216 dev->stats.rx_bytes += skb->len;
217 skb->protocol = hdlc_type_trans(skb, dev);
218 netif_receive_skb(skb);
221 /* Receive DMA service */
222 static inline int sca_rx_done(port_t *port, int budget)
224 struct net_device *dev = port->netdev;
225 u16 dmac = get_dmac_rx(port);
226 card_t *card = port->card;
227 u8 stat = sca_in(DSR_RX(port->chan), card); /* read DMA Status */
230 /* Reset DSR status bits */
231 sca_out((stat & (DSR_EOT | DSR_EOM | DSR_BOF | DSR_COF)) | DSR_DWE,
232 DSR_RX(port->chan), card);
235 /* Dropped one or more frames */
236 dev->stats.rx_over_errors++;
238 while (received < budget) {
239 u32 desc_off = desc_offset(port, port->rxin, 0);
240 pkt_desc __iomem *desc;
241 u32 cda = sca_inl(dmac + CDAL, card);
243 if ((cda >= desc_off) && (cda < desc_off + sizeof(pkt_desc)))
244 break; /* No frame received */
246 desc = desc_address(port, port->rxin, 0);
247 stat = readb(&desc->stat);
248 if (!(stat & ST_RX_EOM))
249 port->rxpart = 1; /* partial frame received */
250 else if ((stat & ST_ERROR_MASK) || port->rxpart) {
251 dev->stats.rx_errors++;
252 if (stat & ST_RX_OVERRUN)
253 dev->stats.rx_fifo_errors++;
254 else if ((stat & (ST_RX_SHORT | ST_RX_ABORT |
255 ST_RX_RESBIT)) || port->rxpart)
256 dev->stats.rx_frame_errors++;
257 else if (stat & ST_RX_CRC)
258 dev->stats.rx_crc_errors++;
259 if (stat & ST_RX_EOM)
260 port->rxpart = 0; /* received last fragment */
262 sca_rx(card, port, desc, port->rxin);
266 /* Set new error descriptor address */
267 sca_outl(desc_off, dmac + EDAL, card);
268 port->rxin = (port->rxin + 1) % card->rx_ring_buffers;
271 /* make sure RX DMA is enabled */
272 sca_out(DSR_DE, DSR_RX(port->chan), card);
276 /* Transmit DMA service */
277 static inline void sca_tx_done(port_t *port)
279 struct net_device *dev = port->netdev;
280 card_t *card = port->card;
284 spin_lock(&port->lock);
286 stat = sca_in(DSR_TX(port->chan), card); /* read DMA Status */
288 /* Reset DSR status bits */
289 sca_out((stat & (DSR_EOT | DSR_EOM | DSR_BOF | DSR_COF)) | DSR_DWE,
290 DSR_TX(port->chan), card);
293 pkt_desc __iomem *desc = desc_address(port, port->txlast, 1);
294 u8 stat = readb(&desc->stat);
296 if (!(stat & ST_TX_OWNRSHP))
297 break; /* not yet transmitted */
298 if (stat & ST_TX_UNDRRUN) {
299 dev->stats.tx_errors++;
300 dev->stats.tx_fifo_errors++;
302 dev->stats.tx_packets++;
303 dev->stats.tx_bytes += readw(&desc->len);
305 writeb(0, &desc->stat); /* Free descriptor */
307 port->txlast = (port->txlast + 1) % card->tx_ring_buffers;
311 netif_wake_queue(dev);
312 spin_unlock(&port->lock);
315 static int sca_poll(struct napi_struct *napi, int budget)
317 port_t *port = container_of(napi, port_t, napi);
318 u32 isr0 = sca_inl(ISR0, port->card);
321 if (isr0 & (port->chan ? 0x08000000 : 0x00080000))
324 if (isr0 & (port->chan ? 0x00002000 : 0x00000020))
327 if (isr0 & (port->chan ? 0x00000200 : 0x00000002))
328 received = sca_rx_done(port, budget);
330 if (received < budget) {
331 napi_complete_done(napi, received);
338 static irqreturn_t sca_intr(int irq, void *dev_id)
340 card_t *card = dev_id;
341 u32 isr0 = sca_inl(ISR0, card);
344 for (i = 0; i < 2; i++) {
345 port_t *port = get_port(card, i);
346 if (port && (isr0 & (i ? 0x08002200 : 0x00080022))) {
349 napi_schedule(&port->napi);
353 return IRQ_RETVAL(handled);
356 static void sca_set_port(port_t *port)
358 card_t *card = port->card;
359 u16 msci = get_msci(port);
360 u8 md2 = sca_in(msci + MD2, card);
361 unsigned int tmc, br = 10, brv = 1024;
363 if (port->settings.clock_rate > 0) {
364 /* Try lower br for better accuracy*/
367 brv >>= 1; /* brv = 2^9 = 512 max in specs */
369 /* Baud Rate = CLOCK_BASE / TMC / 2^BR */
370 tmc = CLOCK_BASE / brv / port->settings.clock_rate;
371 } while (br > 1 && tmc <= 128);
375 br = 0; /* For baud=CLOCK_BASE we use tmc=1 br=0 */
377 } else if (tmc > 255) {
378 tmc = 256; /* tmc=0 means 256 - low baud rates */
381 port->settings.clock_rate = CLOCK_BASE / brv / tmc;
383 br = 9; /* Minimum clock rate */
384 tmc = 256; /* 8bit = 0 */
385 port->settings.clock_rate = CLOCK_BASE / (256 * 512);
388 port->rxs = (port->rxs & ~CLK_BRG_MASK) | br;
389 port->txs = (port->txs & ~CLK_BRG_MASK) | br;
392 /* baud divisor - time constant*/
393 sca_out(port->tmc, msci + TMCR, card);
394 sca_out(port->tmc, msci + TMCT, card);
397 sca_out(port->rxs, msci + RXS, card);
398 sca_out(port->txs, msci + TXS, card);
400 if (port->settings.loopback)
403 md2 &= ~MD2_LOOPBACK;
405 sca_out(md2, msci + MD2, card);
408 static void sca_open(struct net_device *dev)
410 port_t *port = dev_to_port(dev);
411 card_t *card = port->card;
412 u16 msci = get_msci(port);
415 switch (port->encoding) {
422 case ENCODING_FM_MARK:
425 case ENCODING_FM_SPACE:
429 md2 = MD2_MANCHESTER;
432 if (port->settings.loopback)
435 switch (port->parity) {
436 case PARITY_CRC16_PR0:
437 md0 = MD0_HDLC | MD0_CRC_16_0;
439 case PARITY_CRC16_PR1:
440 md0 = MD0_HDLC | MD0_CRC_16;
442 case PARITY_CRC32_PR1_CCITT:
443 md0 = MD0_HDLC | MD0_CRC_ITU32;
445 case PARITY_CRC16_PR1_CCITT:
446 md0 = MD0_HDLC | MD0_CRC_ITU;
449 md0 = MD0_HDLC | MD0_CRC_NONE;
452 sca_out(CMD_RESET, msci + CMD, card);
453 sca_out(md0, msci + MD0, card);
454 sca_out(0x00, msci + MD1, card); /* no address field check */
455 sca_out(md2, msci + MD2, card);
456 sca_out(0x7E, msci + IDL, card); /* flag character 0x7E */
457 /* Skip the rest of underrun frame */
458 sca_out(CTL_IDLE | CTL_URCT | CTL_URSKP, msci + CTL, card);
459 sca_out(0x0F, msci + RNR, card); /* +1=RX DMA activation condition */
460 sca_out(0x3C, msci + TFS, card); /* +1 = TX start */
461 sca_out(0x38, msci + TCR, card); /* =Critical TX DMA activ condition */
462 sca_out(0x38, msci + TNR0, card); /* =TX DMA activation condition */
463 sca_out(0x3F, msci + TNR1, card); /* +1=TX DMA deactivation condition*/
465 /* We're using the following interrupts:
466 - RXINTA (DCD changes only)
467 - DMIB (EOM - single frame transfer complete)
469 sca_outl(IE0_RXINTA | IE0_CDCD, msci + IE0, card);
471 sca_out(port->tmc, msci + TMCR, card);
472 sca_out(port->tmc, msci + TMCT, card);
473 sca_out(port->rxs, msci + RXS, card);
474 sca_out(port->txs, msci + TXS, card);
475 sca_out(CMD_TX_ENABLE, msci + CMD, card);
476 sca_out(CMD_RX_ENABLE, msci + CMD, card);
478 sca_set_carrier(port);
480 napi_enable(&port->napi);
481 netif_start_queue(dev);
484 static void sca_close(struct net_device *dev)
486 port_t *port = dev_to_port(dev);
489 sca_out(CMD_RESET, get_msci(port) + CMD, port->card);
491 napi_disable(&port->napi);
492 netif_stop_queue(dev);
495 static int sca_attach(struct net_device *dev, unsigned short encoding,
496 unsigned short parity)
498 if (encoding != ENCODING_NRZ &&
499 encoding != ENCODING_NRZI &&
500 encoding != ENCODING_FM_MARK &&
501 encoding != ENCODING_FM_SPACE &&
502 encoding != ENCODING_MANCHESTER)
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)
512 dev_to_port(dev)->encoding = encoding;
513 dev_to_port(dev)->parity = parity;
518 static void sca_dump_rings(struct net_device *dev)
520 port_t *port = dev_to_port(dev);
521 card_t *card = port->card;
524 printk(KERN_DEBUG "RX ring: CDA=%u EDA=%u DSR=%02X in=%u %sactive",
525 sca_inl(get_dmac_rx(port) + CDAL, card),
526 sca_inl(get_dmac_rx(port) + EDAL, card),
527 sca_in(DSR_RX(port->chan), card), port->rxin,
528 sca_in(DSR_RX(port->chan), card) & DSR_DE ? "" : "in");
529 for (cnt = 0; cnt < port->card->rx_ring_buffers; cnt++)
530 pr_cont(" %02X", readb(&(desc_address(port, cnt, 0)->stat)));
533 printk(KERN_DEBUG "TX ring: CDA=%u EDA=%u DSR=%02X in=%u "
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");
540 for (cnt = 0; cnt < port->card->tx_ring_buffers; cnt++)
541 pr_cont(" %02X", readb(&(desc_address(port, cnt, 1)->stat)));
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));
558 printk(KERN_DEBUG "ILAR: %02x ISR: %08x %08x\n", sca_in(ILAR, card),
559 sca_inl(ISR0, card), sca_inl(ISR1, card));
561 #endif /* DEBUG_RINGS */
563 static netdev_tx_t sca_xmit(struct sk_buff *skb, struct net_device *dev)
565 port_t *port = dev_to_port(dev);
566 card_t *card = port->card;
567 pkt_desc __iomem *desc;
570 spin_lock_irq(&port->lock);
572 desc = desc_address(port, port->txin + 1, 1);
573 BUG_ON(readb(&desc->stat)); /* previous xmit should stop queue */
576 printk(KERN_DEBUG "%s TX(%i):", dev->name, skb->len);
580 desc = desc_address(port, port->txin, 1);
581 buff = buffer_offset(port, port->txin, 1);
583 memcpy_toio(card->rambase + buff, skb->data, len);
585 writew(len, &desc->len);
586 writeb(ST_TX_EOM, &desc->stat);
588 port->txin = (port->txin + 1) % card->tx_ring_buffers;
589 sca_outl(desc_offset(port, port->txin, 1),
590 get_dmac_tx(port) + EDAL, card);
592 sca_out(DSR_DE, DSR_TX(port->chan), card); /* Enable TX DMA */
594 desc = desc_address(port, port->txin + 1, 1);
595 if (readb(&desc->stat)) /* allow 1 packet gap */
596 netif_stop_queue(dev);
598 spin_unlock_irq(&port->lock);
604 static u32 sca_detect_ram(card_t *card, u8 __iomem *rambase, u32 ramsize)
606 /* Round RAM size to 32 bits, fill from end to start */
607 u32 i = ramsize &= ~3;
611 writel(i ^ 0x12345678, rambase + i);
614 for (i = 0; i < ramsize ; i += 4) {
615 if (readl(rambase + i) != (i ^ 0x12345678))
622 static void sca_init(card_t *card, int wait_states)
624 sca_out(wait_states, WCRL, card); /* Wait Control */
625 sca_out(wait_states, WCRM, card);
626 sca_out(wait_states, WCRH, card);
628 sca_out(0, DMER, card); /* DMA Master disable */
629 sca_out(0x03, PCR, card); /* DMA priority */
630 sca_out(0, DSR_RX(0), card); /* DMA disable - to halt state */
631 sca_out(0, DSR_TX(0), card);
632 sca_out(0, DSR_RX(1), card);
633 sca_out(0, DSR_TX(1), card);
634 sca_out(DMER_DME, DMER, card); /* DMA Master enable */