xref: /linux/drivers/net/wan/n2.c (revision cc04a46f11ea046ed53e2c832ae29e4790f7e35f)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 
21 #include <linux/module.h>
22 #include <linux/kernel.h>
23 #include <linux/capability.h>
24 #include <linux/slab.h>
25 #include <linux/types.h>
26 #include <linux/fcntl.h>
27 #include <linux/in.h>
28 #include <linux/string.h>
29 #include <linux/errno.h>
30 #include <linux/init.h>
31 #include <linux/ioport.h>
32 #include <linux/moduleparam.h>
33 #include <linux/netdevice.h>
34 #include <linux/hdlc.h>
35 #include <asm/io.h>
36 #include "hd64570.h"
37 
38 
39 static const char* version = "SDL RISCom/N2 driver version: 1.15";
40 static const char* devname = "RISCom/N2";
41 
42 #undef DEBUG_PKT
43 #define DEBUG_RINGS
44 
45 #define USE_WINDOWSIZE 16384
46 #define USE_BUS16BITS 1
47 #define CLOCK_BASE 9830400	/* 9.8304 MHz */
48 #define MAX_PAGES      16	/* 16 RAM pages at max */
49 #define MAX_RAM_SIZE 0x80000	/* 512 KB */
50 #if MAX_RAM_SIZE > MAX_PAGES * USE_WINDOWSIZE
51 #undef MAX_RAM_SIZE
52 #define MAX_RAM_SIZE (MAX_PAGES * USE_WINDOWSIZE)
53 #endif
54 #define N2_IOPORTS 0x10
55 #define NEED_DETECT_RAM
56 #define NEED_SCA_MSCI_INTR
57 #define MAX_TX_BUFFERS 10
58 
59 static char *hw;	/* pointer to hw=xxx command line string */
60 
61 /* RISCom/N2 Board Registers */
62 
63 /* PC Control Register */
64 #define N2_PCR 0
65 #define PCR_RUNSCA 1     /* Run 64570 */
66 #define PCR_VPM    2     /* Enable VPM - needed if using RAM above 1 MB */
67 #define PCR_ENWIN  4     /* Open window */
68 #define PCR_BUS16  8     /* 16-bit bus */
69 
70 
71 /* Memory Base Address Register */
72 #define N2_BAR 2
73 
74 
75 /* Page Scan Register  */
76 #define N2_PSR 4
77 #define WIN16K       0x00
78 #define WIN32K       0x20
79 #define WIN64K       0x40
80 #define PSR_WINBITS  0x60
81 #define PSR_DMAEN    0x80
82 #define PSR_PAGEBITS 0x0F
83 
84 
85 /* Modem Control Reg */
86 #define N2_MCR 6
87 #define CLOCK_OUT_PORT1 0x80
88 #define CLOCK_OUT_PORT0 0x40
89 #define TX422_PORT1     0x20
90 #define TX422_PORT0     0x10
91 #define DSR_PORT1       0x08
92 #define DSR_PORT0       0x04
93 #define DTR_PORT1       0x02
94 #define DTR_PORT0       0x01
95 
96 
97 typedef struct port_s {
98 	struct net_device *dev;
99 	struct card_s *card;
100 	spinlock_t lock;	/* TX lock */
101 	sync_serial_settings settings;
102 	int valid;		/* port enabled */
103 	int rxpart;		/* partial frame received, next frame invalid*/
104 	unsigned short encoding;
105 	unsigned short parity;
106 	u16 rxin;		/* rx ring buffer 'in' pointer */
107 	u16 txin;		/* tx ring buffer 'in' and 'last' pointers */
108 	u16 txlast;
109 	u8 rxs, txs, tmc;	/* SCA registers */
110 	u8 phy_node;		/* physical port # - 0 or 1 */
111 	u8 log_node;		/* logical port # */
112 }port_t;
113 
114 
115 
116 typedef struct card_s {
117 	u8 __iomem *winbase;		/* ISA window base address */
118 	u32 phy_winbase;	/* ISA physical base address */
119 	u32 ram_size;		/* number of bytes */
120 	u16 io;			/* IO Base address */
121 	u16 buff_offset;	/* offset of first buffer of first channel */
122 	u16 rx_ring_buffers;	/* number of buffers in a ring */
123 	u16 tx_ring_buffers;
124 	u8 irq;			/* IRQ (3-15) */
125 
126 	port_t ports[2];
127 	struct card_s *next_card;
128 }card_t;
129 
130 
131 static card_t *first_card;
132 static card_t **new_card = &first_card;
133 
134 
135 #define sca_reg(reg, card) (0x8000 | (card)->io | \
136 			    ((reg) & 0x0F) | (((reg) & 0xF0) << 6))
137 #define sca_in(reg, card)		inb(sca_reg(reg, card))
138 #define sca_out(value, reg, card)	outb(value, sca_reg(reg, card))
139 #define sca_inw(reg, card)		inw(sca_reg(reg, card))
140 #define sca_outw(value, reg, card)	outw(value, sca_reg(reg, card))
141 
142 #define port_to_card(port)		((port)->card)
143 #define log_node(port)			((port)->log_node)
144 #define phy_node(port)			((port)->phy_node)
145 #define winsize(card)			(USE_WINDOWSIZE)
146 #define winbase(card)      	     	((card)->winbase)
147 #define get_port(card, port)		((card)->ports[port].valid ? \
148 					 &(card)->ports[port] : NULL)
149 
150 
151 static __inline__ u8 sca_get_page(card_t *card)
152 {
153 	return inb(card->io + N2_PSR) & PSR_PAGEBITS;
154 }
155 
156 
157 static __inline__ void openwin(card_t *card, u8 page)
158 {
159 	u8 psr = inb(card->io + N2_PSR);
160 	outb((psr & ~PSR_PAGEBITS) | page, card->io + N2_PSR);
161 }
162 
163 
164 #include "hd64570.c"
165 
166 
167 static void n2_set_iface(port_t *port)
168 {
169 	card_t *card = port->card;
170 	int io = card->io;
171 	u8 mcr = inb(io + N2_MCR);
172 	u8 msci = get_msci(port);
173 	u8 rxs = port->rxs & CLK_BRG_MASK;
174 	u8 txs = port->txs & CLK_BRG_MASK;
175 
176 	switch(port->settings.clock_type) {
177 	case CLOCK_INT:
178 		mcr |= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
179 		rxs |= CLK_BRG_RX; /* BRG output */
180 		txs |= CLK_RXCLK_TX; /* RX clock */
181 		break;
182 
183 	case CLOCK_TXINT:
184 		mcr |= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
185 		rxs |= CLK_LINE_RX; /* RXC input */
186 		txs |= CLK_BRG_TX; /* BRG output */
187 		break;
188 
189 	case CLOCK_TXFROMRX:
190 		mcr |= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
191 		rxs |= CLK_LINE_RX; /* RXC input */
192 		txs |= CLK_RXCLK_TX; /* RX clock */
193 		break;
194 
195 	default:		/* Clock EXTernal */
196 		mcr &= port->phy_node ? ~CLOCK_OUT_PORT1 : ~CLOCK_OUT_PORT0;
197 		rxs |= CLK_LINE_RX; /* RXC input */
198 		txs |= CLK_LINE_TX; /* TXC input */
199 	}
200 
201 	outb(mcr, io + N2_MCR);
202 	port->rxs = rxs;
203 	port->txs = txs;
204 	sca_out(rxs, msci + RXS, card);
205 	sca_out(txs, msci + TXS, card);
206 	sca_set_port(port);
207 }
208 
209 
210 
211 static int n2_open(struct net_device *dev)
212 {
213 	port_t *port = dev_to_port(dev);
214 	int io = port->card->io;
215 	u8 mcr = inb(io + N2_MCR) | (port->phy_node ? TX422_PORT1:TX422_PORT0);
216 	int result;
217 
218 	result = hdlc_open(dev);
219 	if (result)
220 		return result;
221 
222 	mcr &= port->phy_node ? ~DTR_PORT1 : ~DTR_PORT0; /* set DTR ON */
223 	outb(mcr, io + N2_MCR);
224 
225 	outb(inb(io + N2_PCR) | PCR_ENWIN, io + N2_PCR); /* open window */
226 	outb(inb(io + N2_PSR) | PSR_DMAEN, io + N2_PSR); /* enable dma */
227 	sca_open(dev);
228 	n2_set_iface(port);
229 	return 0;
230 }
231 
232 
233 
234 static int n2_close(struct net_device *dev)
235 {
236 	port_t *port = dev_to_port(dev);
237 	int io = port->card->io;
238 	u8 mcr = inb(io+N2_MCR) | (port->phy_node ? TX422_PORT1 : TX422_PORT0);
239 
240 	sca_close(dev);
241 	mcr |= port->phy_node ? DTR_PORT1 : DTR_PORT0; /* set DTR OFF */
242 	outb(mcr, io + N2_MCR);
243 	hdlc_close(dev);
244 	return 0;
245 }
246 
247 
248 
249 static int n2_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
250 {
251 	const size_t size = sizeof(sync_serial_settings);
252 	sync_serial_settings new_line;
253 	sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
254 	port_t *port = dev_to_port(dev);
255 
256 #ifdef DEBUG_RINGS
257 	if (cmd == SIOCDEVPRIVATE) {
258 		sca_dump_rings(dev);
259 		return 0;
260 	}
261 #endif
262 	if (cmd != SIOCWANDEV)
263 		return hdlc_ioctl(dev, ifr, cmd);
264 
265 	switch(ifr->ifr_settings.type) {
266 	case IF_GET_IFACE:
267 		ifr->ifr_settings.type = IF_IFACE_SYNC_SERIAL;
268 		if (ifr->ifr_settings.size < size) {
269 			ifr->ifr_settings.size = size; /* data size wanted */
270 			return -ENOBUFS;
271 		}
272 		if (copy_to_user(line, &port->settings, size))
273 			return -EFAULT;
274 		return 0;
275 
276 	case IF_IFACE_SYNC_SERIAL:
277 		if(!capable(CAP_NET_ADMIN))
278 			return -EPERM;
279 
280 		if (copy_from_user(&new_line, line, size))
281 			return -EFAULT;
282 
283 		if (new_line.clock_type != CLOCK_EXT &&
284 		    new_line.clock_type != CLOCK_TXFROMRX &&
285 		    new_line.clock_type != CLOCK_INT &&
286 		    new_line.clock_type != CLOCK_TXINT)
287 			return -EINVAL;	/* No such clock setting */
288 
289 		if (new_line.loopback != 0 && new_line.loopback != 1)
290 			return -EINVAL;
291 
292 		memcpy(&port->settings, &new_line, size); /* Update settings */
293 		n2_set_iface(port);
294 		return 0;
295 
296 	default:
297 		return hdlc_ioctl(dev, ifr, cmd);
298 	}
299 }
300 
301 
302 
303 static void n2_destroy_card(card_t *card)
304 {
305 	int cnt;
306 
307 	for (cnt = 0; cnt < 2; cnt++)
308 		if (card->ports[cnt].card) {
309 			struct net_device *dev = port_to_dev(&card->ports[cnt]);
310 			unregister_hdlc_device(dev);
311 		}
312 
313 	if (card->irq)
314 		free_irq(card->irq, card);
315 
316 	if (card->winbase) {
317 		iounmap(card->winbase);
318 		release_mem_region(card->phy_winbase, USE_WINDOWSIZE);
319 	}
320 
321 	if (card->io)
322 		release_region(card->io, N2_IOPORTS);
323 	if (card->ports[0].dev)
324 		free_netdev(card->ports[0].dev);
325 	if (card->ports[1].dev)
326 		free_netdev(card->ports[1].dev);
327 	kfree(card);
328 }
329 
330 static const struct net_device_ops n2_ops = {
331 	.ndo_open       = n2_open,
332 	.ndo_stop       = n2_close,
333 	.ndo_change_mtu = hdlc_change_mtu,
334 	.ndo_start_xmit = hdlc_start_xmit,
335 	.ndo_do_ioctl   = n2_ioctl,
336 };
337 
338 static int __init n2_run(unsigned long io, unsigned long irq,
339 			 unsigned long winbase, long valid0, long valid1)
340 {
341 	card_t *card;
342 	u8 cnt, pcr;
343 	int i;
344 
345 	if (io < 0x200 || io > 0x3FF || (io % N2_IOPORTS) != 0) {
346 		pr_err("invalid I/O port value\n");
347 		return -ENODEV;
348 	}
349 
350 	if (irq < 3 || irq > 15 || irq == 6) /* FIXME */ {
351 		pr_err("invalid IRQ value\n");
352 		return -ENODEV;
353 	}
354 
355 	if (winbase < 0xA0000 || winbase > 0xFFFFF || (winbase & 0xFFF) != 0) {
356 		pr_err("invalid RAM value\n");
357 		return -ENODEV;
358 	}
359 
360 	card = kzalloc(sizeof(card_t), GFP_KERNEL);
361 	if (card == NULL)
362 		return -ENOBUFS;
363 
364 	card->ports[0].dev = alloc_hdlcdev(&card->ports[0]);
365 	card->ports[1].dev = alloc_hdlcdev(&card->ports[1]);
366 	if (!card->ports[0].dev || !card->ports[1].dev) {
367 		pr_err("unable to allocate memory\n");
368 		n2_destroy_card(card);
369 		return -ENOMEM;
370 	}
371 
372 	if (!request_region(io, N2_IOPORTS, devname)) {
373 		pr_err("I/O port region in use\n");
374 		n2_destroy_card(card);
375 		return -EBUSY;
376 	}
377 	card->io = io;
378 
379 	if (request_irq(irq, sca_intr, 0, devname, card)) {
380 		pr_err("could not allocate IRQ\n");
381 		n2_destroy_card(card);
382 		return -EBUSY;
383 	}
384 	card->irq = irq;
385 
386 	if (!request_mem_region(winbase, USE_WINDOWSIZE, devname)) {
387 		pr_err("could not request RAM window\n");
388 		n2_destroy_card(card);
389 		return -EBUSY;
390 	}
391 	card->phy_winbase = winbase;
392 	card->winbase = ioremap(winbase, USE_WINDOWSIZE);
393 	if (!card->winbase) {
394 		pr_err("ioremap() failed\n");
395 		n2_destroy_card(card);
396 		return -EFAULT;
397 	}
398 
399 	outb(0, io + N2_PCR);
400 	outb(winbase >> 12, io + N2_BAR);
401 
402 	switch (USE_WINDOWSIZE) {
403 	case 16384:
404 		outb(WIN16K, io + N2_PSR);
405 		break;
406 
407 	case 32768:
408 		outb(WIN32K, io + N2_PSR);
409 		break;
410 
411 	case 65536:
412 		outb(WIN64K, io + N2_PSR);
413 		break;
414 
415 	default:
416 		pr_err("invalid window size\n");
417 		n2_destroy_card(card);
418 		return -ENODEV;
419 	}
420 
421 	pcr = PCR_ENWIN | PCR_VPM | (USE_BUS16BITS ? PCR_BUS16 : 0);
422 	outb(pcr, io + N2_PCR);
423 
424 	card->ram_size = sca_detect_ram(card, card->winbase, MAX_RAM_SIZE);
425 
426 	/* number of TX + RX buffers for one port */
427 	i = card->ram_size / ((valid0 + valid1) * (sizeof(pkt_desc) +
428 						   HDLC_MAX_MRU));
429 
430 	card->tx_ring_buffers = min(i / 2, MAX_TX_BUFFERS);
431 	card->rx_ring_buffers = i - card->tx_ring_buffers;
432 
433 	card->buff_offset = (valid0 + valid1) * sizeof(pkt_desc) *
434 		(card->tx_ring_buffers + card->rx_ring_buffers);
435 
436 	pr_info("RISCom/N2 %u KB RAM, IRQ%u, using %u TX + %u RX packets rings\n",
437 		card->ram_size / 1024, card->irq,
438 		card->tx_ring_buffers, card->rx_ring_buffers);
439 
440 	if (card->tx_ring_buffers < 1) {
441 		pr_err("RAM test failed\n");
442 		n2_destroy_card(card);
443 		return -EIO;
444 	}
445 
446 	pcr |= PCR_RUNSCA;		/* run SCA */
447 	outb(pcr, io + N2_PCR);
448 	outb(0, io + N2_MCR);
449 
450 	sca_init(card, 0);
451 	for (cnt = 0; cnt < 2; cnt++) {
452 		port_t *port = &card->ports[cnt];
453 		struct net_device *dev = port_to_dev(port);
454 		hdlc_device *hdlc = dev_to_hdlc(dev);
455 
456 		if ((cnt == 0 && !valid0) || (cnt == 1 && !valid1))
457 			continue;
458 
459 		port->phy_node = cnt;
460 		port->valid = 1;
461 
462 		if ((cnt == 1) && valid0)
463 			port->log_node = 1;
464 
465 		spin_lock_init(&port->lock);
466 		dev->irq = irq;
467 		dev->mem_start = winbase;
468 		dev->mem_end = winbase + USE_WINDOWSIZE - 1;
469 		dev->tx_queue_len = 50;
470 		dev->netdev_ops = &n2_ops;
471 		hdlc->attach = sca_attach;
472 		hdlc->xmit = sca_xmit;
473 		port->settings.clock_type = CLOCK_EXT;
474 		port->card = card;
475 
476 		if (register_hdlc_device(dev)) {
477 			pr_warn("unable to register hdlc 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 		netdev_info(dev, "RISCom/N2 node %d\n", port->phy_node);
485 	}
486 
487 	*new_card = card;
488 	new_card = &card->next_card;
489 
490 	return 0;
491 }
492 
493 
494 
495 static int __init n2_init(void)
496 {
497 	if (hw==NULL) {
498 #ifdef MODULE
499 		pr_info("no card initialized\n");
500 #endif
501 		return -EINVAL;	/* no parameters specified, abort */
502 	}
503 
504 	pr_info("%s\n", version);
505 
506 	do {
507 		unsigned long io, irq, ram;
508 		long valid[2] = { 0, 0 }; /* Default = both ports disabled */
509 
510 		io = simple_strtoul(hw, &hw, 0);
511 
512 		if (*hw++ != ',')
513 			break;
514 		irq = simple_strtoul(hw, &hw, 0);
515 
516 		if (*hw++ != ',')
517 			break;
518 		ram = simple_strtoul(hw, &hw, 0);
519 
520 		if (*hw++ != ',')
521 			break;
522 		while(1) {
523 			if (*hw == '0' && !valid[0])
524 				valid[0] = 1; /* Port 0 enabled */
525 			else if (*hw == '1' && !valid[1])
526 				valid[1] = 1; /* Port 1 enabled */
527 			else
528 				break;
529 			hw++;
530 		}
531 
532 		if (!valid[0] && !valid[1])
533 			break;	/* at least one port must be used */
534 
535 		if (*hw == ':' || *hw == '\x0')
536 			n2_run(io, irq, ram, valid[0], valid[1]);
537 
538 		if (*hw == '\x0')
539 			return first_card ? 0 : -EINVAL;
540 	}while(*hw++ == ':');
541 
542 	pr_err("invalid hardware parameters\n");
543 	return first_card ? 0 : -EINVAL;
544 }
545 
546 
547 static void __exit n2_cleanup(void)
548 {
549 	card_t *card = first_card;
550 
551 	while (card) {
552 		card_t *ptr = card;
553 		card = card->next_card;
554 		n2_destroy_card(ptr);
555 	}
556 }
557 
558 
559 module_init(n2_init);
560 module_exit(n2_cleanup);
561 
562 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
563 MODULE_DESCRIPTION("RISCom/N2 serial port driver");
564 MODULE_LICENSE("GPL v2");
565 module_param(hw, charp, 0444);
566 MODULE_PARM_DESC(hw, "io,irq,ram,ports:io,irq,...");
567