xref: /openbmc/linux/drivers/net/wan/n2.c (revision b627b4ed)
1 /*
2  * SDL Inc. RISCom/N2 synchronous serial card driver for Linux
3  *
4  * Copyright (C) 1998-2003 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  * For information see <http://www.kernel.org/pub/linux/utils/net/hdlc/>
11  *
12  * Note: integrated CSU/DSU/DDS are not supported by this driver
13  *
14  * Sources of information:
15  *    Hitachi HD64570 SCA User's Manual
16  *    SDL Inc. PPP/HDLC/CISCO driver
17  */
18 
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/slab.h>
22 #include <linux/types.h>
23 #include <linux/fcntl.h>
24 #include <linux/in.h>
25 #include <linux/string.h>
26 #include <linux/errno.h>
27 #include <linux/init.h>
28 #include <linux/ioport.h>
29 #include <linux/moduleparam.h>
30 #include <linux/netdevice.h>
31 #include <linux/hdlc.h>
32 #include <asm/io.h>
33 #include "hd64570.h"
34 
35 
36 static const char* version = "SDL RISCom/N2 driver version: 1.15";
37 static const char* devname = "RISCom/N2";
38 
39 #undef DEBUG_PKT
40 #define DEBUG_RINGS
41 
42 #define USE_WINDOWSIZE 16384
43 #define USE_BUS16BITS 1
44 #define CLOCK_BASE 9830400	/* 9.8304 MHz */
45 #define MAX_PAGES      16	/* 16 RAM pages at max */
46 #define MAX_RAM_SIZE 0x80000	/* 512 KB */
47 #if MAX_RAM_SIZE > MAX_PAGES * USE_WINDOWSIZE
48 #undef MAX_RAM_SIZE
49 #define MAX_RAM_SIZE (MAX_PAGES * USE_WINDOWSIZE)
50 #endif
51 #define N2_IOPORTS 0x10
52 #define NEED_DETECT_RAM
53 #define NEED_SCA_MSCI_INTR
54 #define MAX_TX_BUFFERS 10
55 
56 static char *hw;	/* pointer to hw=xxx command line string */
57 
58 /* RISCom/N2 Board Registers */
59 
60 /* PC Control Register */
61 #define N2_PCR 0
62 #define PCR_RUNSCA 1     /* Run 64570 */
63 #define PCR_VPM    2     /* Enable VPM - needed if using RAM above 1 MB */
64 #define PCR_ENWIN  4     /* Open window */
65 #define PCR_BUS16  8     /* 16-bit bus */
66 
67 
68 /* Memory Base Address Register */
69 #define N2_BAR 2
70 
71 
72 /* Page Scan Register  */
73 #define N2_PSR 4
74 #define WIN16K       0x00
75 #define WIN32K       0x20
76 #define WIN64K       0x40
77 #define PSR_WINBITS  0x60
78 #define PSR_DMAEN    0x80
79 #define PSR_PAGEBITS 0x0F
80 
81 
82 /* Modem Control Reg */
83 #define N2_MCR 6
84 #define CLOCK_OUT_PORT1 0x80
85 #define CLOCK_OUT_PORT0 0x40
86 #define TX422_PORT1     0x20
87 #define TX422_PORT0     0x10
88 #define DSR_PORT1       0x08
89 #define DSR_PORT0       0x04
90 #define DTR_PORT1       0x02
91 #define DTR_PORT0       0x01
92 
93 
94 typedef struct port_s {
95 	struct net_device *dev;
96 	struct card_s *card;
97 	spinlock_t lock;	/* TX lock */
98 	sync_serial_settings settings;
99 	int valid;		/* port enabled */
100 	int rxpart;		/* partial frame received, next frame invalid*/
101 	unsigned short encoding;
102 	unsigned short parity;
103 	u16 rxin;		/* rx ring buffer 'in' pointer */
104 	u16 txin;		/* tx ring buffer 'in' and 'last' pointers */
105 	u16 txlast;
106 	u8 rxs, txs, tmc;	/* SCA registers */
107 	u8 phy_node;		/* physical port # - 0 or 1 */
108 	u8 log_node;		/* logical port # */
109 }port_t;
110 
111 
112 
113 typedef struct card_s {
114 	u8 __iomem *winbase;		/* ISA window base address */
115 	u32 phy_winbase;	/* ISA physical base address */
116 	u32 ram_size;		/* number of bytes */
117 	u16 io;			/* IO Base address */
118 	u16 buff_offset;	/* offset of first buffer of first channel */
119 	u16 rx_ring_buffers;	/* number of buffers in a ring */
120 	u16 tx_ring_buffers;
121 	u8 irq;			/* IRQ (3-15) */
122 
123 	port_t ports[2];
124 	struct card_s *next_card;
125 }card_t;
126 
127 
128 static card_t *first_card;
129 static card_t **new_card = &first_card;
130 
131 
132 #define sca_reg(reg, card) (0x8000 | (card)->io | \
133 			    ((reg) & 0x0F) | (((reg) & 0xF0) << 6))
134 #define sca_in(reg, card)		inb(sca_reg(reg, card))
135 #define sca_out(value, reg, card)	outb(value, sca_reg(reg, card))
136 #define sca_inw(reg, card)		inw(sca_reg(reg, card))
137 #define sca_outw(value, reg, card)	outw(value, sca_reg(reg, card))
138 
139 #define port_to_card(port)		((port)->card)
140 #define log_node(port)			((port)->log_node)
141 #define phy_node(port)			((port)->phy_node)
142 #define winsize(card)			(USE_WINDOWSIZE)
143 #define winbase(card)      	     	((card)->winbase)
144 #define get_port(card, port)		((card)->ports[port].valid ? \
145 					 &(card)->ports[port] : NULL)
146 
147 
148 static __inline__ u8 sca_get_page(card_t *card)
149 {
150 	return inb(card->io + N2_PSR) & PSR_PAGEBITS;
151 }
152 
153 
154 static __inline__ void openwin(card_t *card, u8 page)
155 {
156 	u8 psr = inb(card->io + N2_PSR);
157 	outb((psr & ~PSR_PAGEBITS) | page, card->io + N2_PSR);
158 }
159 
160 
161 #include "hd64570.c"
162 
163 
164 static void n2_set_iface(port_t *port)
165 {
166 	card_t *card = port->card;
167 	int io = card->io;
168 	u8 mcr = inb(io + N2_MCR);
169 	u8 msci = get_msci(port);
170 	u8 rxs = port->rxs & CLK_BRG_MASK;
171 	u8 txs = port->txs & CLK_BRG_MASK;
172 
173 	switch(port->settings.clock_type) {
174 	case CLOCK_INT:
175 		mcr |= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
176 		rxs |= CLK_BRG_RX; /* BRG output */
177 		txs |= CLK_RXCLK_TX; /* RX clock */
178 		break;
179 
180 	case CLOCK_TXINT:
181 		mcr |= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
182 		rxs |= CLK_LINE_RX; /* RXC input */
183 		txs |= CLK_BRG_TX; /* BRG output */
184 		break;
185 
186 	case CLOCK_TXFROMRX:
187 		mcr |= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
188 		rxs |= CLK_LINE_RX; /* RXC input */
189 		txs |= CLK_RXCLK_TX; /* RX clock */
190 		break;
191 
192 	default:		/* Clock EXTernal */
193 		mcr &= port->phy_node ? ~CLOCK_OUT_PORT1 : ~CLOCK_OUT_PORT0;
194 		rxs |= CLK_LINE_RX; /* RXC input */
195 		txs |= CLK_LINE_TX; /* TXC input */
196 	}
197 
198 	outb(mcr, io + N2_MCR);
199 	port->rxs = rxs;
200 	port->txs = txs;
201 	sca_out(rxs, msci + RXS, card);
202 	sca_out(txs, msci + TXS, card);
203 	sca_set_port(port);
204 }
205 
206 
207 
208 static int n2_open(struct net_device *dev)
209 {
210 	port_t *port = dev_to_port(dev);
211 	int io = port->card->io;
212 	u8 mcr = inb(io + N2_MCR) | (port->phy_node ? TX422_PORT1:TX422_PORT0);
213 	int result;
214 
215 	result = hdlc_open(dev);
216 	if (result)
217 		return result;
218 
219 	mcr &= port->phy_node ? ~DTR_PORT1 : ~DTR_PORT0; /* set DTR ON */
220 	outb(mcr, io + N2_MCR);
221 
222 	outb(inb(io + N2_PCR) | PCR_ENWIN, io + N2_PCR); /* open window */
223 	outb(inb(io + N2_PSR) | PSR_DMAEN, io + N2_PSR); /* enable dma */
224 	sca_open(dev);
225 	n2_set_iface(port);
226 	return 0;
227 }
228 
229 
230 
231 static int n2_close(struct net_device *dev)
232 {
233 	port_t *port = dev_to_port(dev);
234 	int io = port->card->io;
235 	u8 mcr = inb(io+N2_MCR) | (port->phy_node ? TX422_PORT1 : TX422_PORT0);
236 
237 	sca_close(dev);
238 	mcr |= port->phy_node ? DTR_PORT1 : DTR_PORT0; /* set DTR OFF */
239 	outb(mcr, io + N2_MCR);
240 	hdlc_close(dev);
241 	return 0;
242 }
243 
244 
245 
246 static int n2_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
247 {
248 	const size_t size = sizeof(sync_serial_settings);
249 	sync_serial_settings new_line;
250 	sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
251 	port_t *port = dev_to_port(dev);
252 
253 #ifdef DEBUG_RINGS
254 	if (cmd == SIOCDEVPRIVATE) {
255 		sca_dump_rings(dev);
256 		return 0;
257 	}
258 #endif
259 	if (cmd != SIOCWANDEV)
260 		return hdlc_ioctl(dev, ifr, cmd);
261 
262 	switch(ifr->ifr_settings.type) {
263 	case IF_GET_IFACE:
264 		ifr->ifr_settings.type = IF_IFACE_SYNC_SERIAL;
265 		if (ifr->ifr_settings.size < size) {
266 			ifr->ifr_settings.size = size; /* data size wanted */
267 			return -ENOBUFS;
268 		}
269 		if (copy_to_user(line, &port->settings, size))
270 			return -EFAULT;
271 		return 0;
272 
273 	case IF_IFACE_SYNC_SERIAL:
274 		if(!capable(CAP_NET_ADMIN))
275 			return -EPERM;
276 
277 		if (copy_from_user(&new_line, line, size))
278 			return -EFAULT;
279 
280 		if (new_line.clock_type != CLOCK_EXT &&
281 		    new_line.clock_type != CLOCK_TXFROMRX &&
282 		    new_line.clock_type != CLOCK_INT &&
283 		    new_line.clock_type != CLOCK_TXINT)
284 		return -EINVAL;	/* No such clock setting */
285 
286 		if (new_line.loopback != 0 && new_line.loopback != 1)
287 			return -EINVAL;
288 
289 		memcpy(&port->settings, &new_line, size); /* Update settings */
290 		n2_set_iface(port);
291 		return 0;
292 
293 	default:
294 		return hdlc_ioctl(dev, ifr, cmd);
295 	}
296 }
297 
298 
299 
300 static void n2_destroy_card(card_t *card)
301 {
302 	int cnt;
303 
304 	for (cnt = 0; cnt < 2; cnt++)
305 		if (card->ports[cnt].card) {
306 			struct net_device *dev = port_to_dev(&card->ports[cnt]);
307 			unregister_hdlc_device(dev);
308 		}
309 
310 	if (card->irq)
311 		free_irq(card->irq, card);
312 
313 	if (card->winbase) {
314 		iounmap(card->winbase);
315 		release_mem_region(card->phy_winbase, USE_WINDOWSIZE);
316 	}
317 
318 	if (card->io)
319 		release_region(card->io, N2_IOPORTS);
320 	if (card->ports[0].dev)
321 		free_netdev(card->ports[0].dev);
322 	if (card->ports[1].dev)
323 		free_netdev(card->ports[1].dev);
324 	kfree(card);
325 }
326 
327 static const struct net_device_ops n2_ops = {
328 	.ndo_open       = n2_open,
329 	.ndo_stop       = n2_close,
330 	.ndo_change_mtu = hdlc_change_mtu,
331 	.ndo_start_xmit = hdlc_start_xmit,
332 	.ndo_do_ioctl   = n2_ioctl,
333 };
334 
335 static int __init n2_run(unsigned long io, unsigned long irq,
336 			 unsigned long winbase, long valid0, long valid1)
337 {
338 	card_t *card;
339 	u8 cnt, pcr;
340 	int i;
341 
342 	if (io < 0x200 || io > 0x3FF || (io % N2_IOPORTS) != 0) {
343 		printk(KERN_ERR "n2: invalid I/O port value\n");
344 		return -ENODEV;
345 	}
346 
347 	if (irq < 3 || irq > 15 || irq == 6) /* FIXME */ {
348 		printk(KERN_ERR "n2: invalid IRQ value\n");
349 		return -ENODEV;
350 	}
351 
352 	if (winbase < 0xA0000 || winbase > 0xFFFFF || (winbase & 0xFFF) != 0) {
353 		printk(KERN_ERR "n2: invalid RAM value\n");
354 		return -ENODEV;
355 	}
356 
357 	card = kzalloc(sizeof(card_t), GFP_KERNEL);
358 	if (card == NULL) {
359 		printk(KERN_ERR "n2: unable to allocate memory\n");
360 		return -ENOBUFS;
361 	}
362 
363 	card->ports[0].dev = alloc_hdlcdev(&card->ports[0]);
364 	card->ports[1].dev = alloc_hdlcdev(&card->ports[1]);
365 	if (!card->ports[0].dev || !card->ports[1].dev) {
366 		printk(KERN_ERR "n2: unable to allocate memory\n");
367 		n2_destroy_card(card);
368 		return -ENOMEM;
369 	}
370 
371 	if (!request_region(io, N2_IOPORTS, devname)) {
372 		printk(KERN_ERR "n2: I/O port region in use\n");
373 		n2_destroy_card(card);
374 		return -EBUSY;
375 	}
376 	card->io = io;
377 
378 	if (request_irq(irq, &sca_intr, 0, devname, card)) {
379 		printk(KERN_ERR "n2: could not allocate IRQ\n");
380 		n2_destroy_card(card);
381 		return(-EBUSY);
382 	}
383 	card->irq = irq;
384 
385 	if (!request_mem_region(winbase, USE_WINDOWSIZE, devname)) {
386 		printk(KERN_ERR "n2: could not request RAM window\n");
387 		n2_destroy_card(card);
388 		return(-EBUSY);
389 	}
390 	card->phy_winbase = winbase;
391 	card->winbase = ioremap(winbase, USE_WINDOWSIZE);
392 	if (!card->winbase) {
393 		printk(KERN_ERR "n2: ioremap() failed\n");
394 		n2_destroy_card(card);
395 		return -EFAULT;
396 	}
397 
398 	outb(0, io + N2_PCR);
399 	outb(winbase >> 12, io + N2_BAR);
400 
401 	switch (USE_WINDOWSIZE) {
402 	case 16384:
403 		outb(WIN16K, io + N2_PSR);
404 		break;
405 
406 	case 32768:
407 		outb(WIN32K, io + N2_PSR);
408 		break;
409 
410 	case 65536:
411 		outb(WIN64K, io + N2_PSR);
412 		break;
413 
414 	default:
415 		printk(KERN_ERR "n2: invalid window size\n");
416 		n2_destroy_card(card);
417 		return -ENODEV;
418 	}
419 
420 	pcr = PCR_ENWIN | PCR_VPM | (USE_BUS16BITS ? PCR_BUS16 : 0);
421 	outb(pcr, io + N2_PCR);
422 
423 	card->ram_size = sca_detect_ram(card, card->winbase, MAX_RAM_SIZE);
424 
425 	/* number of TX + RX buffers for one port */
426 	i = card->ram_size / ((valid0 + valid1) * (sizeof(pkt_desc) +
427 						   HDLC_MAX_MRU));
428 
429 	card->tx_ring_buffers = min(i / 2, MAX_TX_BUFFERS);
430 	card->rx_ring_buffers = i - card->tx_ring_buffers;
431 
432 	card->buff_offset = (valid0 + valid1) * sizeof(pkt_desc) *
433 		(card->tx_ring_buffers + card->rx_ring_buffers);
434 
435 	printk(KERN_INFO "n2: RISCom/N2 %u KB RAM, IRQ%u, "
436 	       "using %u TX + %u RX packets rings\n", card->ram_size / 1024,
437 	       card->irq, card->tx_ring_buffers, card->rx_ring_buffers);
438 
439 	if (card->tx_ring_buffers < 1) {
440 		printk(KERN_ERR "n2: RAM test failed\n");
441 		n2_destroy_card(card);
442 		return -EIO;
443 	}
444 
445 	pcr |= PCR_RUNSCA;		/* run SCA */
446 	outb(pcr, io + N2_PCR);
447 	outb(0, io + N2_MCR);
448 
449 	sca_init(card, 0);
450 	for (cnt = 0; cnt < 2; cnt++) {
451 		port_t *port = &card->ports[cnt];
452 		struct net_device *dev = port_to_dev(port);
453 		hdlc_device *hdlc = dev_to_hdlc(dev);
454 
455 		if ((cnt == 0 && !valid0) || (cnt == 1 && !valid1))
456 			continue;
457 
458 		port->phy_node = cnt;
459 		port->valid = 1;
460 
461 		if ((cnt == 1) && valid0)
462 			port->log_node = 1;
463 
464 		spin_lock_init(&port->lock);
465 		dev->irq = irq;
466 		dev->mem_start = winbase;
467 		dev->mem_end = winbase + USE_WINDOWSIZE - 1;
468 		dev->tx_queue_len = 50;
469 		dev->netdev_ops = &n2_ops;
470 		hdlc->attach = sca_attach;
471 		hdlc->xmit = sca_xmit;
472 		port->settings.clock_type = CLOCK_EXT;
473 		port->card = card;
474 
475 		if (register_hdlc_device(dev)) {
476 			printk(KERN_WARNING "n2: unable to register hdlc "
477 			       "device\n");
478 			port->card = NULL;
479 			n2_destroy_card(card);
480 			return -ENOBUFS;
481 		}
482 		sca_init_port(port); /* Set up SCA memory */
483 
484 		printk(KERN_INFO "%s: RISCom/N2 node %d\n",
485 		       dev->name, port->phy_node);
486 	}
487 
488 	*new_card = card;
489 	new_card = &card->next_card;
490 
491 	return 0;
492 }
493 
494 
495 
496 static int __init n2_init(void)
497 {
498 	if (hw==NULL) {
499 #ifdef MODULE
500 		printk(KERN_INFO "n2: no card initialized\n");
501 #endif
502 		return -EINVAL;	/* no parameters specified, abort */
503 	}
504 
505 	printk(KERN_INFO "%s\n", version);
506 
507 	do {
508 		unsigned long io, irq, ram;
509 		long valid[2] = { 0, 0 }; /* Default = both ports disabled */
510 
511 		io = simple_strtoul(hw, &hw, 0);
512 
513 		if (*hw++ != ',')
514 			break;
515 		irq = simple_strtoul(hw, &hw, 0);
516 
517 		if (*hw++ != ',')
518 			break;
519 		ram = simple_strtoul(hw, &hw, 0);
520 
521 		if (*hw++ != ',')
522 			break;
523 		while(1) {
524 			if (*hw == '0' && !valid[0])
525 				valid[0] = 1; /* Port 0 enabled */
526 			else if (*hw == '1' && !valid[1])
527 				valid[1] = 1; /* Port 1 enabled */
528 			else
529 				break;
530 			hw++;
531 		}
532 
533 		if (!valid[0] && !valid[1])
534 			break;	/* at least one port must be used */
535 
536 		if (*hw == ':' || *hw == '\x0')
537 			n2_run(io, irq, ram, valid[0], valid[1]);
538 
539 		if (*hw == '\x0')
540 			return first_card ? 0 : -EINVAL;
541 	}while(*hw++ == ':');
542 
543 	printk(KERN_ERR "n2: invalid hardware parameters\n");
544 	return first_card ? 0 : -EINVAL;
545 }
546 
547 
548 static void __exit n2_cleanup(void)
549 {
550 	card_t *card = first_card;
551 
552 	while (card) {
553 		card_t *ptr = card;
554 		card = card->next_card;
555 		n2_destroy_card(ptr);
556 	}
557 }
558 
559 
560 module_init(n2_init);
561 module_exit(n2_cleanup);
562 
563 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
564 MODULE_DESCRIPTION("RISCom/N2 serial port driver");
565 MODULE_LICENSE("GPL v2");
566 module_param(hw, charp, 0444);
567 MODULE_PARM_DESC(hw, "io,irq,ram,ports:io,irq,...");
568