xref: /linux/drivers/net/wan/n2.c (revision 8ea636848aca35b9f97c5b5dee30225cf2dd0fe6)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SDL Inc. RISCom/N2 synchronous serial card driver for Linux
4  *
5  * Copyright (C) 1998-2003 Krzysztof Halasa <khc@pm.waw.pl>
6  *
7  * For information see <https://www.kernel.org/pub/linux/utils/net/hdlc/>
8  *
9  * Note: integrated CSU/DSU/DDS are not supported by this driver
10  *
11  * Sources of information:
12  *    Hitachi HD64570 SCA User's Manual
13  *    SDL Inc. PPP/HDLC/CISCO driver
14  */
15 
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 
18 #include <linux/module.h>
19 #include <linux/kernel.h>
20 #include <linux/capability.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_start_xmit = hdlc_start_xmit,
331 	.ndo_do_ioctl   = n2_ioctl,
332 };
333 
334 static int __init n2_run(unsigned long io, unsigned long irq,
335 			 unsigned long winbase, long valid0, long valid1)
336 {
337 	card_t *card;
338 	u8 cnt, pcr;
339 	int i;
340 
341 	if (io < 0x200 || io > 0x3FF || (io % N2_IOPORTS) != 0) {
342 		pr_err("invalid I/O port value\n");
343 		return -ENODEV;
344 	}
345 
346 	if (irq < 3 || irq > 15 || irq == 6) /* FIXME */ {
347 		pr_err("invalid IRQ value\n");
348 		return -ENODEV;
349 	}
350 
351 	if (winbase < 0xA0000 || winbase > 0xFFFFF || (winbase & 0xFFF) != 0) {
352 		pr_err("invalid RAM value\n");
353 		return -ENODEV;
354 	}
355 
356 	card = kzalloc(sizeof(card_t), GFP_KERNEL);
357 	if (card == NULL)
358 		return -ENOBUFS;
359 
360 	card->ports[0].dev = alloc_hdlcdev(&card->ports[0]);
361 	card->ports[1].dev = alloc_hdlcdev(&card->ports[1]);
362 	if (!card->ports[0].dev || !card->ports[1].dev) {
363 		pr_err("unable to allocate memory\n");
364 		n2_destroy_card(card);
365 		return -ENOMEM;
366 	}
367 
368 	if (!request_region(io, N2_IOPORTS, devname)) {
369 		pr_err("I/O port region in use\n");
370 		n2_destroy_card(card);
371 		return -EBUSY;
372 	}
373 	card->io = io;
374 
375 	if (request_irq(irq, sca_intr, 0, devname, card)) {
376 		pr_err("could not allocate IRQ\n");
377 		n2_destroy_card(card);
378 		return -EBUSY;
379 	}
380 	card->irq = irq;
381 
382 	if (!request_mem_region(winbase, USE_WINDOWSIZE, devname)) {
383 		pr_err("could not request RAM window\n");
384 		n2_destroy_card(card);
385 		return -EBUSY;
386 	}
387 	card->phy_winbase = winbase;
388 	card->winbase = ioremap(winbase, USE_WINDOWSIZE);
389 	if (!card->winbase) {
390 		pr_err("ioremap() failed\n");
391 		n2_destroy_card(card);
392 		return -EFAULT;
393 	}
394 
395 	outb(0, io + N2_PCR);
396 	outb(winbase >> 12, io + N2_BAR);
397 
398 	switch (USE_WINDOWSIZE) {
399 	case 16384:
400 		outb(WIN16K, io + N2_PSR);
401 		break;
402 
403 	case 32768:
404 		outb(WIN32K, io + N2_PSR);
405 		break;
406 
407 	case 65536:
408 		outb(WIN64K, io + N2_PSR);
409 		break;
410 
411 	default:
412 		pr_err("invalid window size\n");
413 		n2_destroy_card(card);
414 		return -ENODEV;
415 	}
416 
417 	pcr = PCR_ENWIN | PCR_VPM | (USE_BUS16BITS ? PCR_BUS16 : 0);
418 	outb(pcr, io + N2_PCR);
419 
420 	card->ram_size = sca_detect_ram(card, card->winbase, MAX_RAM_SIZE);
421 
422 	/* number of TX + RX buffers for one port */
423 	i = card->ram_size / ((valid0 + valid1) * (sizeof(pkt_desc) +
424 						   HDLC_MAX_MRU));
425 
426 	card->tx_ring_buffers = min(i / 2, MAX_TX_BUFFERS);
427 	card->rx_ring_buffers = i - card->tx_ring_buffers;
428 
429 	card->buff_offset = (valid0 + valid1) * sizeof(pkt_desc) *
430 		(card->tx_ring_buffers + card->rx_ring_buffers);
431 
432 	pr_info("RISCom/N2 %u KB RAM, IRQ%u, using %u TX + %u RX packets rings\n",
433 		card->ram_size / 1024, card->irq,
434 		card->tx_ring_buffers, card->rx_ring_buffers);
435 
436 	if (card->tx_ring_buffers < 1) {
437 		pr_err("RAM test failed\n");
438 		n2_destroy_card(card);
439 		return -EIO;
440 	}
441 
442 	pcr |= PCR_RUNSCA;		/* run SCA */
443 	outb(pcr, io + N2_PCR);
444 	outb(0, io + N2_MCR);
445 
446 	sca_init(card, 0);
447 	for (cnt = 0; cnt < 2; cnt++) {
448 		port_t *port = &card->ports[cnt];
449 		struct net_device *dev = port_to_dev(port);
450 		hdlc_device *hdlc = dev_to_hdlc(dev);
451 
452 		if ((cnt == 0 && !valid0) || (cnt == 1 && !valid1))
453 			continue;
454 
455 		port->phy_node = cnt;
456 		port->valid = 1;
457 
458 		if ((cnt == 1) && valid0)
459 			port->log_node = 1;
460 
461 		spin_lock_init(&port->lock);
462 		dev->irq = irq;
463 		dev->mem_start = winbase;
464 		dev->mem_end = winbase + USE_WINDOWSIZE - 1;
465 		dev->tx_queue_len = 50;
466 		dev->netdev_ops = &n2_ops;
467 		hdlc->attach = sca_attach;
468 		hdlc->xmit = sca_xmit;
469 		port->settings.clock_type = CLOCK_EXT;
470 		port->card = card;
471 
472 		if (register_hdlc_device(dev)) {
473 			pr_warn("unable to register hdlc device\n");
474 			port->card = NULL;
475 			n2_destroy_card(card);
476 			return -ENOBUFS;
477 		}
478 		sca_init_port(port); /* Set up SCA memory */
479 
480 		netdev_info(dev, "RISCom/N2 node %d\n", port->phy_node);
481 	}
482 
483 	*new_card = card;
484 	new_card = &card->next_card;
485 
486 	return 0;
487 }
488 
489 
490 
491 static int __init n2_init(void)
492 {
493 	if (hw==NULL) {
494 #ifdef MODULE
495 		pr_info("no card initialized\n");
496 #endif
497 		return -EINVAL;	/* no parameters specified, abort */
498 	}
499 
500 	pr_info("%s\n", version);
501 
502 	do {
503 		unsigned long io, irq, ram;
504 		long valid[2] = { 0, 0 }; /* Default = both ports disabled */
505 
506 		io = simple_strtoul(hw, &hw, 0);
507 
508 		if (*hw++ != ',')
509 			break;
510 		irq = simple_strtoul(hw, &hw, 0);
511 
512 		if (*hw++ != ',')
513 			break;
514 		ram = simple_strtoul(hw, &hw, 0);
515 
516 		if (*hw++ != ',')
517 			break;
518 		while(1) {
519 			if (*hw == '0' && !valid[0])
520 				valid[0] = 1; /* Port 0 enabled */
521 			else if (*hw == '1' && !valid[1])
522 				valid[1] = 1; /* Port 1 enabled */
523 			else
524 				break;
525 			hw++;
526 		}
527 
528 		if (!valid[0] && !valid[1])
529 			break;	/* at least one port must be used */
530 
531 		if (*hw == ':' || *hw == '\x0')
532 			n2_run(io, irq, ram, valid[0], valid[1]);
533 
534 		if (*hw == '\x0')
535 			return first_card ? 0 : -EINVAL;
536 	}while(*hw++ == ':');
537 
538 	pr_err("invalid hardware parameters\n");
539 	return first_card ? 0 : -EINVAL;
540 }
541 
542 
543 static void __exit n2_cleanup(void)
544 {
545 	card_t *card = first_card;
546 
547 	while (card) {
548 		card_t *ptr = card;
549 		card = card->next_card;
550 		n2_destroy_card(ptr);
551 	}
552 }
553 
554 
555 module_init(n2_init);
556 module_exit(n2_cleanup);
557 
558 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
559 MODULE_DESCRIPTION("RISCom/N2 serial port driver");
560 MODULE_LICENSE("GPL v2");
561 module_param(hw, charp, 0444);
562 MODULE_PARM_DESC(hw, "io,irq,ram,ports:io,irq,...");
563