xref: /openbmc/linux/drivers/net/wan/n2.c (revision e2c75e76)
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_start_xmit = hdlc_start_xmit,
334 	.ndo_do_ioctl   = n2_ioctl,
335 };
336 
337 static int __init n2_run(unsigned long io, unsigned long irq,
338 			 unsigned long winbase, long valid0, long valid1)
339 {
340 	card_t *card;
341 	u8 cnt, pcr;
342 	int i;
343 
344 	if (io < 0x200 || io > 0x3FF || (io % N2_IOPORTS) != 0) {
345 		pr_err("invalid I/O port value\n");
346 		return -ENODEV;
347 	}
348 
349 	if (irq < 3 || irq > 15 || irq == 6) /* FIXME */ {
350 		pr_err("invalid IRQ value\n");
351 		return -ENODEV;
352 	}
353 
354 	if (winbase < 0xA0000 || winbase > 0xFFFFF || (winbase & 0xFFF) != 0) {
355 		pr_err("invalid RAM value\n");
356 		return -ENODEV;
357 	}
358 
359 	card = kzalloc(sizeof(card_t), GFP_KERNEL);
360 	if (card == NULL)
361 		return -ENOBUFS;
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 		pr_err("unable to allocate memory\n");
367 		n2_destroy_card(card);
368 		return -ENOMEM;
369 	}
370 
371 	if (!request_region(io, N2_IOPORTS, devname)) {
372 		pr_err("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 		pr_err("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 		pr_err("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 		pr_err("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 		pr_err("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 	pr_info("RISCom/N2 %u KB RAM, IRQ%u, using %u TX + %u RX packets rings\n",
436 		card->ram_size / 1024, card->irq,
437 		card->tx_ring_buffers, card->rx_ring_buffers);
438 
439 	if (card->tx_ring_buffers < 1) {
440 		pr_err("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 			pr_warn("unable to register hdlc device\n");
477 			port->card = NULL;
478 			n2_destroy_card(card);
479 			return -ENOBUFS;
480 		}
481 		sca_init_port(port); /* Set up SCA memory */
482 
483 		netdev_info(dev, "RISCom/N2 node %d\n", port->phy_node);
484 	}
485 
486 	*new_card = card;
487 	new_card = &card->next_card;
488 
489 	return 0;
490 }
491 
492 
493 
494 static int __init n2_init(void)
495 {
496 	if (hw==NULL) {
497 #ifdef MODULE
498 		pr_info("no card initialized\n");
499 #endif
500 		return -EINVAL;	/* no parameters specified, abort */
501 	}
502 
503 	pr_info("%s\n", version);
504 
505 	do {
506 		unsigned long io, irq, ram;
507 		long valid[2] = { 0, 0 }; /* Default = both ports disabled */
508 
509 		io = simple_strtoul(hw, &hw, 0);
510 
511 		if (*hw++ != ',')
512 			break;
513 		irq = simple_strtoul(hw, &hw, 0);
514 
515 		if (*hw++ != ',')
516 			break;
517 		ram = simple_strtoul(hw, &hw, 0);
518 
519 		if (*hw++ != ',')
520 			break;
521 		while(1) {
522 			if (*hw == '0' && !valid[0])
523 				valid[0] = 1; /* Port 0 enabled */
524 			else if (*hw == '1' && !valid[1])
525 				valid[1] = 1; /* Port 1 enabled */
526 			else
527 				break;
528 			hw++;
529 		}
530 
531 		if (!valid[0] && !valid[1])
532 			break;	/* at least one port must be used */
533 
534 		if (*hw == ':' || *hw == '\x0')
535 			n2_run(io, irq, ram, valid[0], valid[1]);
536 
537 		if (*hw == '\x0')
538 			return first_card ? 0 : -EINVAL;
539 	}while(*hw++ == ':');
540 
541 	pr_err("invalid hardware parameters\n");
542 	return first_card ? 0 : -EINVAL;
543 }
544 
545 
546 static void __exit n2_cleanup(void)
547 {
548 	card_t *card = first_card;
549 
550 	while (card) {
551 		card_t *ptr = card;
552 		card = card->next_card;
553 		n2_destroy_card(ptr);
554 	}
555 }
556 
557 
558 module_init(n2_init);
559 module_exit(n2_cleanup);
560 
561 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
562 MODULE_DESCRIPTION("RISCom/N2 serial port driver");
563 MODULE_LICENSE("GPL v2");
564 module_param(hw, charp, 0444);
565 MODULE_PARM_DESC(hw, "io,irq,ram,ports:io,irq,...");
566