1 /*
2 * Driver for high-speed SCC boards (those with DMA support)
3 * Copyright (C) 1997-2000 Klaus Kudielka
4 *
5 * S5SCC/DMA support by Janko Koleznik S52HI
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22
23 #include <linux/module.h>
24 #include <linux/bitops.h>
25 #include <linux/delay.h>
26 #include <linux/errno.h>
27 #include <linux/if_arp.h>
28 #include <linux/in.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/ioport.h>
32 #include <linux/kernel.h>
33 #include <linux/mm.h>
34 #include <linux/netdevice.h>
35 #include <linux/slab.h>
36 #include <linux/rtnetlink.h>
37 #include <linux/sockios.h>
38 #include <linux/workqueue.h>
39 #include <linux/atomic.h>
40 #include <asm/dma.h>
41 #include <asm/io.h>
42 #include <asm/irq.h>
43 #include <linux/uaccess.h>
44 #include <net/ax25.h>
45 #include "z8530.h"
46
47
48 /* Number of buffers per channel */
49
50 #define NUM_TX_BUF 2 /* NUM_TX_BUF >= 1 (min. 2 recommended) */
51 #define NUM_RX_BUF 6 /* NUM_RX_BUF >= 1 (min. 2 recommended) */
52 #define BUF_SIZE 1576 /* BUF_SIZE >= mtu + hard_header_len */
53
54
55 /* Cards supported */
56
57 #define HW_PI { "Ottawa PI", 0x300, 0x20, 0x10, 8, \
58 0, 8, 1843200, 3686400 }
59 #define HW_PI2 { "Ottawa PI2", 0x300, 0x20, 0x10, 8, \
60 0, 8, 3686400, 7372800 }
61 #define HW_TWIN { "Gracilis PackeTwin", 0x200, 0x10, 0x10, 32, \
62 0, 4, 6144000, 6144000 }
63 #define HW_S5 { "S5SCC/DMA", 0x200, 0x10, 0x10, 32, \
64 0, 8, 4915200, 9830400 }
65
66 #define HARDWARE { HW_PI, HW_PI2, HW_TWIN, HW_S5 }
67
68 #define TMR_0_HZ 25600 /* Frequency of timer 0 */
69
70 #define TYPE_PI 0
71 #define TYPE_PI2 1
72 #define TYPE_TWIN 2
73 #define TYPE_S5 3
74 #define NUM_TYPES 4
75
76 #define MAX_NUM_DEVS 32
77
78
79 /* SCC chips supported */
80
81 #define Z8530 0
82 #define Z85C30 1
83 #define Z85230 2
84
85 #define CHIPNAMES { "Z8530", "Z85C30", "Z85230" }
86
87
88 /* I/O registers */
89
90 /* 8530 registers relative to card base */
91 #define SCCB_CMD 0x00
92 #define SCCB_DATA 0x01
93 #define SCCA_CMD 0x02
94 #define SCCA_DATA 0x03
95
96 /* 8253/8254 registers relative to card base */
97 #define TMR_CNT0 0x00
98 #define TMR_CNT1 0x01
99 #define TMR_CNT2 0x02
100 #define TMR_CTRL 0x03
101
102 /* Additional PI/PI2 registers relative to card base */
103 #define PI_DREQ_MASK 0x04
104
105 /* Additional PackeTwin registers relative to card base */
106 #define TWIN_INT_REG 0x08
107 #define TWIN_CLR_TMR1 0x09
108 #define TWIN_CLR_TMR2 0x0a
109 #define TWIN_SPARE_1 0x0b
110 #define TWIN_DMA_CFG 0x08
111 #define TWIN_SERIAL_CFG 0x09
112 #define TWIN_DMA_CLR_FF 0x0a
113 #define TWIN_SPARE_2 0x0b
114
115
116 /* PackeTwin I/O register values */
117
118 /* INT_REG */
119 #define TWIN_SCC_MSK 0x01
120 #define TWIN_TMR1_MSK 0x02
121 #define TWIN_TMR2_MSK 0x04
122 #define TWIN_INT_MSK 0x07
123
124 /* SERIAL_CFG */
125 #define TWIN_DTRA_ON 0x01
126 #define TWIN_DTRB_ON 0x02
127 #define TWIN_EXTCLKA 0x04
128 #define TWIN_EXTCLKB 0x08
129 #define TWIN_LOOPA_ON 0x10
130 #define TWIN_LOOPB_ON 0x20
131 #define TWIN_EI 0x80
132
133 /* DMA_CFG */
134 #define TWIN_DMA_HDX_T1 0x08
135 #define TWIN_DMA_HDX_R1 0x0a
136 #define TWIN_DMA_HDX_T3 0x14
137 #define TWIN_DMA_HDX_R3 0x16
138 #define TWIN_DMA_FDX_T3R1 0x1b
139 #define TWIN_DMA_FDX_T1R3 0x1d
140
141
142 /* Status values */
143
144 #define IDLE 0
145 #define TX_HEAD 1
146 #define TX_DATA 2
147 #define TX_PAUSE 3
148 #define TX_TAIL 4
149 #define RTS_OFF 5
150 #define WAIT 6
151 #define DCD_ON 7
152 #define RX_ON 8
153 #define DCD_OFF 9
154
155
156 /* Ioctls */
157
158 #define SIOCGSCCPARAM SIOCDEVPRIVATE
159 #define SIOCSSCCPARAM (SIOCDEVPRIVATE+1)
160
161
162 /* Data types */
163
164 struct scc_param {
165 int pclk_hz; /* frequency of BRG input (don't change) */
166 int brg_tc; /* BRG terminal count; BRG disabled if < 0 */
167 int nrzi; /* 0 (nrz), 1 (nrzi) */
168 int clocks; /* see dmascc_cfg documentation */
169 int txdelay; /* [1/TMR_0_HZ] */
170 int txtimeout; /* [1/HZ] */
171 int txtail; /* [1/TMR_0_HZ] */
172 int waittime; /* [1/TMR_0_HZ] */
173 int slottime; /* [1/TMR_0_HZ] */
174 int persist; /* 1 ... 256 */
175 int dma; /* -1 (disable), 0, 1, 3 */
176 int txpause; /* [1/TMR_0_HZ] */
177 int rtsoff; /* [1/TMR_0_HZ] */
178 int dcdon; /* [1/TMR_0_HZ] */
179 int dcdoff; /* [1/TMR_0_HZ] */
180 };
181
182 struct scc_hardware {
183 char *name;
184 int io_region;
185 int io_delta;
186 int io_size;
187 int num_devs;
188 int scc_offset;
189 int tmr_offset;
190 int tmr_hz;
191 int pclk_hz;
192 };
193
194 struct scc_priv {
195 int type;
196 int chip;
197 struct net_device *dev;
198 struct scc_info *info;
199
200 int channel;
201 int card_base, scc_cmd, scc_data;
202 int tmr_cnt, tmr_ctrl, tmr_mode;
203 struct scc_param param;
204 char rx_buf[NUM_RX_BUF][BUF_SIZE];
205 int rx_len[NUM_RX_BUF];
206 int rx_ptr;
207 struct work_struct rx_work;
208 int rx_head, rx_tail, rx_count;
209 int rx_over;
210 char tx_buf[NUM_TX_BUF][BUF_SIZE];
211 int tx_len[NUM_TX_BUF];
212 int tx_ptr;
213 int tx_head, tx_tail, tx_count;
214 int state;
215 unsigned long tx_start;
216 int rr0;
217 spinlock_t *register_lock; /* Per scc_info */
218 spinlock_t ring_lock;
219 };
220
221 struct scc_info {
222 int irq_used;
223 int twin_serial_cfg;
224 struct net_device *dev[2];
225 struct scc_priv priv[2];
226 struct scc_info *next;
227 spinlock_t register_lock; /* Per device register lock */
228 };
229
230
231 /* Function declarations */
232 static int setup_adapter(int card_base, int type, int n) __init;
233
234 static void write_scc(struct scc_priv *priv, int reg, int val);
235 static void write_scc_data(struct scc_priv *priv, int val, int fast);
236 static int read_scc(struct scc_priv *priv, int reg);
237 static int read_scc_data(struct scc_priv *priv);
238
239 static int scc_open(struct net_device *dev);
240 static int scc_close(struct net_device *dev);
241 static int scc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
242 static int scc_send_packet(struct sk_buff *skb, struct net_device *dev);
243 static int scc_set_mac_address(struct net_device *dev, void *sa);
244
245 static inline void tx_on(struct scc_priv *priv);
246 static inline void rx_on(struct scc_priv *priv);
247 static inline void rx_off(struct scc_priv *priv);
248 static void start_timer(struct scc_priv *priv, int t, int r15);
249 static inline unsigned char random(void);
250
251 static inline void z8530_isr(struct scc_info *info);
252 static irqreturn_t scc_isr(int irq, void *dev_id);
253 static void rx_isr(struct scc_priv *priv);
254 static void special_condition(struct scc_priv *priv, int rc);
255 static void rx_bh(struct work_struct *);
256 static void tx_isr(struct scc_priv *priv);
257 static void es_isr(struct scc_priv *priv);
258 static void tm_isr(struct scc_priv *priv);
259
260
261 /* Initialization variables */
262
263 static int io[MAX_NUM_DEVS] __initdata = { 0, };
264
265 /* Beware! hw[] is also used in dmascc_exit(). */
266 static struct scc_hardware hw[NUM_TYPES] = HARDWARE;
267
268
269 /* Global variables */
270
271 static struct scc_info *first;
272 static unsigned long rand;
273
274
275 MODULE_AUTHOR("Klaus Kudielka");
276 MODULE_DESCRIPTION("Driver for high-speed SCC boards");
277 module_param_hw_array(io, int, ioport, NULL, 0);
278 MODULE_LICENSE("GPL");
279
dmascc_exit(void)280 static void __exit dmascc_exit(void)
281 {
282 int i;
283 struct scc_info *info;
284
285 while (first) {
286 info = first;
287
288 /* Unregister devices */
289 for (i = 0; i < 2; i++)
290 unregister_netdev(info->dev[i]);
291
292 /* Reset board */
293 if (info->priv[0].type == TYPE_TWIN)
294 outb(0, info->dev[0]->base_addr + TWIN_SERIAL_CFG);
295 write_scc(&info->priv[0], R9, FHWRES);
296 release_region(info->dev[0]->base_addr,
297 hw[info->priv[0].type].io_size);
298
299 for (i = 0; i < 2; i++)
300 free_netdev(info->dev[i]);
301
302 /* Free memory */
303 first = info->next;
304 kfree(info);
305 }
306 }
307
dmascc_init(void)308 static int __init dmascc_init(void)
309 {
310 int h, i, j, n;
311 int base[MAX_NUM_DEVS], tcmd[MAX_NUM_DEVS], t0[MAX_NUM_DEVS],
312 t1[MAX_NUM_DEVS];
313 unsigned t_val;
314 unsigned long time, start[MAX_NUM_DEVS], delay[MAX_NUM_DEVS],
315 counting[MAX_NUM_DEVS];
316
317 /* Initialize random number generator */
318 rand = jiffies;
319 /* Cards found = 0 */
320 n = 0;
321 /* Warning message */
322 if (!io[0])
323 printk(KERN_INFO "dmascc: autoprobing (dangerous)\n");
324
325 /* Run autodetection for each card type */
326 for (h = 0; h < NUM_TYPES; h++) {
327
328 if (io[0]) {
329 /* User-specified I/O address regions */
330 for (i = 0; i < hw[h].num_devs; i++)
331 base[i] = 0;
332 for (i = 0; i < MAX_NUM_DEVS && io[i]; i++) {
333 j = (io[i] -
334 hw[h].io_region) / hw[h].io_delta;
335 if (j >= 0 && j < hw[h].num_devs &&
336 hw[h].io_region +
337 j * hw[h].io_delta == io[i]) {
338 base[j] = io[i];
339 }
340 }
341 } else {
342 /* Default I/O address regions */
343 for (i = 0; i < hw[h].num_devs; i++) {
344 base[i] =
345 hw[h].io_region + i * hw[h].io_delta;
346 }
347 }
348
349 /* Check valid I/O address regions */
350 for (i = 0; i < hw[h].num_devs; i++)
351 if (base[i]) {
352 if (!request_region
353 (base[i], hw[h].io_size, "dmascc"))
354 base[i] = 0;
355 else {
356 tcmd[i] =
357 base[i] + hw[h].tmr_offset +
358 TMR_CTRL;
359 t0[i] =
360 base[i] + hw[h].tmr_offset +
361 TMR_CNT0;
362 t1[i] =
363 base[i] + hw[h].tmr_offset +
364 TMR_CNT1;
365 }
366 }
367
368 /* Start timers */
369 for (i = 0; i < hw[h].num_devs; i++)
370 if (base[i]) {
371 /* Timer 0: LSB+MSB, Mode 3, TMR_0_HZ */
372 outb(0x36, tcmd[i]);
373 outb((hw[h].tmr_hz / TMR_0_HZ) & 0xFF,
374 t0[i]);
375 outb((hw[h].tmr_hz / TMR_0_HZ) >> 8,
376 t0[i]);
377 /* Timer 1: LSB+MSB, Mode 0, HZ/10 */
378 outb(0x70, tcmd[i]);
379 outb((TMR_0_HZ / HZ * 10) & 0xFF, t1[i]);
380 outb((TMR_0_HZ / HZ * 10) >> 8, t1[i]);
381 start[i] = jiffies;
382 delay[i] = 0;
383 counting[i] = 1;
384 /* Timer 2: LSB+MSB, Mode 0 */
385 outb(0xb0, tcmd[i]);
386 }
387 time = jiffies;
388 /* Wait until counter registers are loaded */
389 udelay(2000000 / TMR_0_HZ);
390
391 /* Timing loop */
392 while (jiffies - time < 13) {
393 for (i = 0; i < hw[h].num_devs; i++)
394 if (base[i] && counting[i]) {
395 /* Read back Timer 1: latch; read LSB; read MSB */
396 outb(0x40, tcmd[i]);
397 t_val =
398 inb(t1[i]) + (inb(t1[i]) << 8);
399 /* Also check whether counter did wrap */
400 if (t_val == 0 ||
401 t_val > TMR_0_HZ / HZ * 10)
402 counting[i] = 0;
403 delay[i] = jiffies - start[i];
404 }
405 }
406
407 /* Evaluate measurements */
408 for (i = 0; i < hw[h].num_devs; i++)
409 if (base[i]) {
410 if ((delay[i] >= 9 && delay[i] <= 11) &&
411 /* Ok, we have found an adapter */
412 (setup_adapter(base[i], h, n) == 0))
413 n++;
414 else
415 release_region(base[i],
416 hw[h].io_size);
417 }
418
419 } /* NUM_TYPES */
420
421 /* If any adapter was successfully initialized, return ok */
422 if (n)
423 return 0;
424
425 /* If no adapter found, return error */
426 printk(KERN_INFO "dmascc: no adapters found\n");
427 return -EIO;
428 }
429
430 module_init(dmascc_init);
431 module_exit(dmascc_exit);
432
dev_setup(struct net_device * dev)433 static void __init dev_setup(struct net_device *dev)
434 {
435 dev->type = ARPHRD_AX25;
436 dev->hard_header_len = AX25_MAX_HEADER_LEN;
437 dev->mtu = 1500;
438 dev->addr_len = AX25_ADDR_LEN;
439 dev->tx_queue_len = 64;
440 memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
441 memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
442 }
443
444 static const struct net_device_ops scc_netdev_ops = {
445 .ndo_open = scc_open,
446 .ndo_stop = scc_close,
447 .ndo_start_xmit = scc_send_packet,
448 .ndo_do_ioctl = scc_ioctl,
449 .ndo_set_mac_address = scc_set_mac_address,
450 };
451
setup_adapter(int card_base,int type,int n)452 static int __init setup_adapter(int card_base, int type, int n)
453 {
454 int i, irq, chip, err;
455 struct scc_info *info;
456 struct net_device *dev;
457 struct scc_priv *priv;
458 unsigned long time;
459 unsigned int irqs;
460 int tmr_base = card_base + hw[type].tmr_offset;
461 int scc_base = card_base + hw[type].scc_offset;
462 char *chipnames[] = CHIPNAMES;
463
464 /* Initialize what is necessary for write_scc and write_scc_data */
465 info = kzalloc(sizeof(struct scc_info), GFP_KERNEL | GFP_DMA);
466 if (!info) {
467 err = -ENOMEM;
468 goto out;
469 }
470
471 info->dev[0] = alloc_netdev(0, "", NET_NAME_UNKNOWN, dev_setup);
472 if (!info->dev[0]) {
473 printk(KERN_ERR "dmascc: "
474 "could not allocate memory for %s at %#3x\n",
475 hw[type].name, card_base);
476 err = -ENOMEM;
477 goto out1;
478 }
479
480 info->dev[1] = alloc_netdev(0, "", NET_NAME_UNKNOWN, dev_setup);
481 if (!info->dev[1]) {
482 printk(KERN_ERR "dmascc: "
483 "could not allocate memory for %s at %#3x\n",
484 hw[type].name, card_base);
485 err = -ENOMEM;
486 goto out2;
487 }
488 spin_lock_init(&info->register_lock);
489
490 priv = &info->priv[0];
491 priv->type = type;
492 priv->card_base = card_base;
493 priv->scc_cmd = scc_base + SCCA_CMD;
494 priv->scc_data = scc_base + SCCA_DATA;
495 priv->register_lock = &info->register_lock;
496
497 /* Reset SCC */
498 write_scc(priv, R9, FHWRES | MIE | NV);
499
500 /* Determine type of chip by enabling SDLC/HDLC enhancements */
501 write_scc(priv, R15, SHDLCE);
502 if (!read_scc(priv, R15)) {
503 /* WR7' not present. This is an ordinary Z8530 SCC. */
504 chip = Z8530;
505 } else {
506 /* Put one character in TX FIFO */
507 write_scc_data(priv, 0, 0);
508 if (read_scc(priv, R0) & Tx_BUF_EMP) {
509 /* TX FIFO not full. This is a Z85230 ESCC with a 4-byte FIFO. */
510 chip = Z85230;
511 } else {
512 /* TX FIFO full. This is a Z85C30 SCC with a 1-byte FIFO. */
513 chip = Z85C30;
514 }
515 }
516 write_scc(priv, R15, 0);
517
518 /* Start IRQ auto-detection */
519 irqs = probe_irq_on();
520
521 /* Enable interrupts */
522 if (type == TYPE_TWIN) {
523 outb(0, card_base + TWIN_DMA_CFG);
524 inb(card_base + TWIN_CLR_TMR1);
525 inb(card_base + TWIN_CLR_TMR2);
526 info->twin_serial_cfg = TWIN_EI;
527 outb(info->twin_serial_cfg, card_base + TWIN_SERIAL_CFG);
528 } else {
529 write_scc(priv, R15, CTSIE);
530 write_scc(priv, R0, RES_EXT_INT);
531 write_scc(priv, R1, EXT_INT_ENAB);
532 }
533
534 /* Start timer */
535 outb(1, tmr_base + TMR_CNT1);
536 outb(0, tmr_base + TMR_CNT1);
537
538 /* Wait and detect IRQ */
539 time = jiffies;
540 while (jiffies - time < 2 + HZ / TMR_0_HZ);
541 irq = probe_irq_off(irqs);
542
543 /* Clear pending interrupt, disable interrupts */
544 if (type == TYPE_TWIN) {
545 inb(card_base + TWIN_CLR_TMR1);
546 } else {
547 write_scc(priv, R1, 0);
548 write_scc(priv, R15, 0);
549 write_scc(priv, R0, RES_EXT_INT);
550 }
551
552 if (irq <= 0) {
553 printk(KERN_ERR
554 "dmascc: could not find irq of %s at %#3x (irq=%d)\n",
555 hw[type].name, card_base, irq);
556 err = -ENODEV;
557 goto out3;
558 }
559
560 /* Set up data structures */
561 for (i = 0; i < 2; i++) {
562 dev = info->dev[i];
563 priv = &info->priv[i];
564 priv->type = type;
565 priv->chip = chip;
566 priv->dev = dev;
567 priv->info = info;
568 priv->channel = i;
569 spin_lock_init(&priv->ring_lock);
570 priv->register_lock = &info->register_lock;
571 priv->card_base = card_base;
572 priv->scc_cmd = scc_base + (i ? SCCB_CMD : SCCA_CMD);
573 priv->scc_data = scc_base + (i ? SCCB_DATA : SCCA_DATA);
574 priv->tmr_cnt = tmr_base + (i ? TMR_CNT2 : TMR_CNT1);
575 priv->tmr_ctrl = tmr_base + TMR_CTRL;
576 priv->tmr_mode = i ? 0xb0 : 0x70;
577 priv->param.pclk_hz = hw[type].pclk_hz;
578 priv->param.brg_tc = -1;
579 priv->param.clocks = TCTRxCP | RCRTxCP;
580 priv->param.persist = 256;
581 priv->param.dma = -1;
582 INIT_WORK(&priv->rx_work, rx_bh);
583 dev->ml_priv = priv;
584 snprintf(dev->name, sizeof(dev->name), "dmascc%i", 2 * n + i);
585 dev->base_addr = card_base;
586 dev->irq = irq;
587 dev->netdev_ops = &scc_netdev_ops;
588 dev->header_ops = &ax25_header_ops;
589 }
590 if (register_netdev(info->dev[0])) {
591 printk(KERN_ERR "dmascc: could not register %s\n",
592 info->dev[0]->name);
593 err = -ENODEV;
594 goto out3;
595 }
596 if (register_netdev(info->dev[1])) {
597 printk(KERN_ERR "dmascc: could not register %s\n",
598 info->dev[1]->name);
599 err = -ENODEV;
600 goto out4;
601 }
602
603
604 info->next = first;
605 first = info;
606 printk(KERN_INFO "dmascc: found %s (%s) at %#3x, irq %d\n",
607 hw[type].name, chipnames[chip], card_base, irq);
608 return 0;
609
610 out4:
611 unregister_netdev(info->dev[0]);
612 out3:
613 if (info->priv[0].type == TYPE_TWIN)
614 outb(0, info->dev[0]->base_addr + TWIN_SERIAL_CFG);
615 write_scc(&info->priv[0], R9, FHWRES);
616 free_netdev(info->dev[1]);
617 out2:
618 free_netdev(info->dev[0]);
619 out1:
620 kfree(info);
621 out:
622 return err;
623 }
624
625
626 /* Driver functions */
627
write_scc(struct scc_priv * priv,int reg,int val)628 static void write_scc(struct scc_priv *priv, int reg, int val)
629 {
630 unsigned long flags;
631 switch (priv->type) {
632 case TYPE_S5:
633 if (reg)
634 outb(reg, priv->scc_cmd);
635 outb(val, priv->scc_cmd);
636 return;
637 case TYPE_TWIN:
638 if (reg)
639 outb_p(reg, priv->scc_cmd);
640 outb_p(val, priv->scc_cmd);
641 return;
642 default:
643 spin_lock_irqsave(priv->register_lock, flags);
644 outb_p(0, priv->card_base + PI_DREQ_MASK);
645 if (reg)
646 outb_p(reg, priv->scc_cmd);
647 outb_p(val, priv->scc_cmd);
648 outb(1, priv->card_base + PI_DREQ_MASK);
649 spin_unlock_irqrestore(priv->register_lock, flags);
650 return;
651 }
652 }
653
654
write_scc_data(struct scc_priv * priv,int val,int fast)655 static void write_scc_data(struct scc_priv *priv, int val, int fast)
656 {
657 unsigned long flags;
658 switch (priv->type) {
659 case TYPE_S5:
660 outb(val, priv->scc_data);
661 return;
662 case TYPE_TWIN:
663 outb_p(val, priv->scc_data);
664 return;
665 default:
666 if (fast)
667 outb_p(val, priv->scc_data);
668 else {
669 spin_lock_irqsave(priv->register_lock, flags);
670 outb_p(0, priv->card_base + PI_DREQ_MASK);
671 outb_p(val, priv->scc_data);
672 outb(1, priv->card_base + PI_DREQ_MASK);
673 spin_unlock_irqrestore(priv->register_lock, flags);
674 }
675 return;
676 }
677 }
678
679
read_scc(struct scc_priv * priv,int reg)680 static int read_scc(struct scc_priv *priv, int reg)
681 {
682 int rc;
683 unsigned long flags;
684 switch (priv->type) {
685 case TYPE_S5:
686 if (reg)
687 outb(reg, priv->scc_cmd);
688 return inb(priv->scc_cmd);
689 case TYPE_TWIN:
690 if (reg)
691 outb_p(reg, priv->scc_cmd);
692 return inb_p(priv->scc_cmd);
693 default:
694 spin_lock_irqsave(priv->register_lock, flags);
695 outb_p(0, priv->card_base + PI_DREQ_MASK);
696 if (reg)
697 outb_p(reg, priv->scc_cmd);
698 rc = inb_p(priv->scc_cmd);
699 outb(1, priv->card_base + PI_DREQ_MASK);
700 spin_unlock_irqrestore(priv->register_lock, flags);
701 return rc;
702 }
703 }
704
705
read_scc_data(struct scc_priv * priv)706 static int read_scc_data(struct scc_priv *priv)
707 {
708 int rc;
709 unsigned long flags;
710 switch (priv->type) {
711 case TYPE_S5:
712 return inb(priv->scc_data);
713 case TYPE_TWIN:
714 return inb_p(priv->scc_data);
715 default:
716 spin_lock_irqsave(priv->register_lock, flags);
717 outb_p(0, priv->card_base + PI_DREQ_MASK);
718 rc = inb_p(priv->scc_data);
719 outb(1, priv->card_base + PI_DREQ_MASK);
720 spin_unlock_irqrestore(priv->register_lock, flags);
721 return rc;
722 }
723 }
724
725
scc_open(struct net_device * dev)726 static int scc_open(struct net_device *dev)
727 {
728 struct scc_priv *priv = dev->ml_priv;
729 struct scc_info *info = priv->info;
730 int card_base = priv->card_base;
731
732 /* Request IRQ if not already used by other channel */
733 if (!info->irq_used) {
734 if (request_irq(dev->irq, scc_isr, 0, "dmascc", info)) {
735 return -EAGAIN;
736 }
737 }
738 info->irq_used++;
739
740 /* Request DMA if required */
741 if (priv->param.dma >= 0) {
742 if (request_dma(priv->param.dma, "dmascc")) {
743 if (--info->irq_used == 0)
744 free_irq(dev->irq, info);
745 return -EAGAIN;
746 } else {
747 unsigned long flags = claim_dma_lock();
748 clear_dma_ff(priv->param.dma);
749 release_dma_lock(flags);
750 }
751 }
752
753 /* Initialize local variables */
754 priv->rx_ptr = 0;
755 priv->rx_over = 0;
756 priv->rx_head = priv->rx_tail = priv->rx_count = 0;
757 priv->state = IDLE;
758 priv->tx_head = priv->tx_tail = priv->tx_count = 0;
759 priv->tx_ptr = 0;
760
761 /* Reset channel */
762 write_scc(priv, R9, (priv->channel ? CHRB : CHRA) | MIE | NV);
763 /* X1 clock, SDLC mode */
764 write_scc(priv, R4, SDLC | X1CLK);
765 /* DMA */
766 write_scc(priv, R1, EXT_INT_ENAB | WT_FN_RDYFN);
767 /* 8 bit RX char, RX disable */
768 write_scc(priv, R3, Rx8);
769 /* 8 bit TX char, TX disable */
770 write_scc(priv, R5, Tx8);
771 /* SDLC address field */
772 write_scc(priv, R6, 0);
773 /* SDLC flag */
774 write_scc(priv, R7, FLAG);
775 switch (priv->chip) {
776 case Z85C30:
777 /* Select WR7' */
778 write_scc(priv, R15, SHDLCE);
779 /* Auto EOM reset */
780 write_scc(priv, R7, AUTOEOM);
781 write_scc(priv, R15, 0);
782 break;
783 case Z85230:
784 /* Select WR7' */
785 write_scc(priv, R15, SHDLCE);
786 /* The following bits are set (see 2.5.2.1):
787 - Automatic EOM reset
788 - Interrupt request if RX FIFO is half full
789 This bit should be ignored in DMA mode (according to the
790 documentation), but actually isn't. The receiver doesn't work if
791 it is set. Thus, we have to clear it in DMA mode.
792 - Interrupt/DMA request if TX FIFO is completely empty
793 a) If set, the ESCC behaves as if it had no TX FIFO (Z85C30
794 compatibility).
795 b) If cleared, DMA requests may follow each other very quickly,
796 filling up the TX FIFO.
797 Advantage: TX works even in case of high bus latency.
798 Disadvantage: Edge-triggered DMA request circuitry may miss
799 a request. No more data is delivered, resulting
800 in a TX FIFO underrun.
801 Both PI2 and S5SCC/DMA seem to work fine with TXFIFOE cleared.
802 The PackeTwin doesn't. I don't know about the PI, but let's
803 assume it behaves like the PI2.
804 */
805 if (priv->param.dma >= 0) {
806 if (priv->type == TYPE_TWIN)
807 write_scc(priv, R7, AUTOEOM | TXFIFOE);
808 else
809 write_scc(priv, R7, AUTOEOM);
810 } else {
811 write_scc(priv, R7, AUTOEOM | RXFIFOH);
812 }
813 write_scc(priv, R15, 0);
814 break;
815 }
816 /* Preset CRC, NRZ(I) encoding */
817 write_scc(priv, R10, CRCPS | (priv->param.nrzi ? NRZI : NRZ));
818
819 /* Configure baud rate generator */
820 if (priv->param.brg_tc >= 0) {
821 /* Program BR generator */
822 write_scc(priv, R12, priv->param.brg_tc & 0xFF);
823 write_scc(priv, R13, (priv->param.brg_tc >> 8) & 0xFF);
824 /* BRG source = SYS CLK; enable BRG; DTR REQ function (required by
825 PackeTwin, not connected on the PI2); set DPLL source to BRG */
826 write_scc(priv, R14, SSBR | DTRREQ | BRSRC | BRENABL);
827 /* Enable DPLL */
828 write_scc(priv, R14, SEARCH | DTRREQ | BRSRC | BRENABL);
829 } else {
830 /* Disable BR generator */
831 write_scc(priv, R14, DTRREQ | BRSRC);
832 }
833
834 /* Configure clocks */
835 if (priv->type == TYPE_TWIN) {
836 /* Disable external TX clock receiver */
837 outb((info->twin_serial_cfg &=
838 ~(priv->channel ? TWIN_EXTCLKB : TWIN_EXTCLKA)),
839 card_base + TWIN_SERIAL_CFG);
840 }
841 write_scc(priv, R11, priv->param.clocks);
842 if ((priv->type == TYPE_TWIN) && !(priv->param.clocks & TRxCOI)) {
843 /* Enable external TX clock receiver */
844 outb((info->twin_serial_cfg |=
845 (priv->channel ? TWIN_EXTCLKB : TWIN_EXTCLKA)),
846 card_base + TWIN_SERIAL_CFG);
847 }
848
849 /* Configure PackeTwin */
850 if (priv->type == TYPE_TWIN) {
851 /* Assert DTR, enable interrupts */
852 outb((info->twin_serial_cfg |= TWIN_EI |
853 (priv->channel ? TWIN_DTRB_ON : TWIN_DTRA_ON)),
854 card_base + TWIN_SERIAL_CFG);
855 }
856
857 /* Read current status */
858 priv->rr0 = read_scc(priv, R0);
859 /* Enable DCD interrupt */
860 write_scc(priv, R15, DCDIE);
861
862 netif_start_queue(dev);
863
864 return 0;
865 }
866
867
scc_close(struct net_device * dev)868 static int scc_close(struct net_device *dev)
869 {
870 struct scc_priv *priv = dev->ml_priv;
871 struct scc_info *info = priv->info;
872 int card_base = priv->card_base;
873
874 netif_stop_queue(dev);
875
876 if (priv->type == TYPE_TWIN) {
877 /* Drop DTR */
878 outb((info->twin_serial_cfg &=
879 (priv->channel ? ~TWIN_DTRB_ON : ~TWIN_DTRA_ON)),
880 card_base + TWIN_SERIAL_CFG);
881 }
882
883 /* Reset channel, free DMA and IRQ */
884 write_scc(priv, R9, (priv->channel ? CHRB : CHRA) | MIE | NV);
885 if (priv->param.dma >= 0) {
886 if (priv->type == TYPE_TWIN)
887 outb(0, card_base + TWIN_DMA_CFG);
888 free_dma(priv->param.dma);
889 }
890 if (--info->irq_used == 0)
891 free_irq(dev->irq, info);
892
893 return 0;
894 }
895
896
scc_ioctl(struct net_device * dev,struct ifreq * ifr,int cmd)897 static int scc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
898 {
899 struct scc_priv *priv = dev->ml_priv;
900
901 switch (cmd) {
902 case SIOCGSCCPARAM:
903 if (copy_to_user
904 (ifr->ifr_data, &priv->param,
905 sizeof(struct scc_param)))
906 return -EFAULT;
907 return 0;
908 case SIOCSSCCPARAM:
909 if (!capable(CAP_NET_ADMIN))
910 return -EPERM;
911 if (netif_running(dev))
912 return -EAGAIN;
913 if (copy_from_user
914 (&priv->param, ifr->ifr_data,
915 sizeof(struct scc_param)))
916 return -EFAULT;
917 return 0;
918 default:
919 return -EINVAL;
920 }
921 }
922
923
scc_send_packet(struct sk_buff * skb,struct net_device * dev)924 static int scc_send_packet(struct sk_buff *skb, struct net_device *dev)
925 {
926 struct scc_priv *priv = dev->ml_priv;
927 unsigned long flags;
928 int i;
929
930 if (skb->protocol == htons(ETH_P_IP))
931 return ax25_ip_xmit(skb);
932
933 /* Temporarily stop the scheduler feeding us packets */
934 netif_stop_queue(dev);
935
936 /* Transfer data to DMA buffer */
937 i = priv->tx_head;
938 skb_copy_from_linear_data_offset(skb, 1, priv->tx_buf[i], skb->len - 1);
939 priv->tx_len[i] = skb->len - 1;
940
941 /* Clear interrupts while we touch our circular buffers */
942
943 spin_lock_irqsave(&priv->ring_lock, flags);
944 /* Move the ring buffer's head */
945 priv->tx_head = (i + 1) % NUM_TX_BUF;
946 priv->tx_count++;
947
948 /* If we just filled up the last buffer, leave queue stopped.
949 The higher layers must wait until we have a DMA buffer
950 to accept the data. */
951 if (priv->tx_count < NUM_TX_BUF)
952 netif_wake_queue(dev);
953
954 /* Set new TX state */
955 if (priv->state == IDLE) {
956 /* Assert RTS, start timer */
957 priv->state = TX_HEAD;
958 priv->tx_start = jiffies;
959 write_scc(priv, R5, TxCRC_ENAB | RTS | TxENAB | Tx8);
960 write_scc(priv, R15, 0);
961 start_timer(priv, priv->param.txdelay, 0);
962 }
963
964 /* Turn interrupts back on and free buffer */
965 spin_unlock_irqrestore(&priv->ring_lock, flags);
966 dev_kfree_skb(skb);
967
968 return NETDEV_TX_OK;
969 }
970
971
scc_set_mac_address(struct net_device * dev,void * sa)972 static int scc_set_mac_address(struct net_device *dev, void *sa)
973 {
974 memcpy(dev->dev_addr, ((struct sockaddr *) sa)->sa_data,
975 dev->addr_len);
976 return 0;
977 }
978
979
tx_on(struct scc_priv * priv)980 static inline void tx_on(struct scc_priv *priv)
981 {
982 int i, n;
983 unsigned long flags;
984
985 if (priv->param.dma >= 0) {
986 n = (priv->chip == Z85230) ? 3 : 1;
987 /* Program DMA controller */
988 flags = claim_dma_lock();
989 set_dma_mode(priv->param.dma, DMA_MODE_WRITE);
990 set_dma_addr(priv->param.dma,
991 (int) priv->tx_buf[priv->tx_tail] + n);
992 set_dma_count(priv->param.dma,
993 priv->tx_len[priv->tx_tail] - n);
994 release_dma_lock(flags);
995 /* Enable TX underrun interrupt */
996 write_scc(priv, R15, TxUIE);
997 /* Configure DREQ */
998 if (priv->type == TYPE_TWIN)
999 outb((priv->param.dma ==
1000 1) ? TWIN_DMA_HDX_T1 : TWIN_DMA_HDX_T3,
1001 priv->card_base + TWIN_DMA_CFG);
1002 else
1003 write_scc(priv, R1,
1004 EXT_INT_ENAB | WT_FN_RDYFN |
1005 WT_RDY_ENAB);
1006 /* Write first byte(s) */
1007 spin_lock_irqsave(priv->register_lock, flags);
1008 for (i = 0; i < n; i++)
1009 write_scc_data(priv,
1010 priv->tx_buf[priv->tx_tail][i], 1);
1011 enable_dma(priv->param.dma);
1012 spin_unlock_irqrestore(priv->register_lock, flags);
1013 } else {
1014 write_scc(priv, R15, TxUIE);
1015 write_scc(priv, R1,
1016 EXT_INT_ENAB | WT_FN_RDYFN | TxINT_ENAB);
1017 tx_isr(priv);
1018 }
1019 /* Reset EOM latch if we do not have the AUTOEOM feature */
1020 if (priv->chip == Z8530)
1021 write_scc(priv, R0, RES_EOM_L);
1022 }
1023
1024
rx_on(struct scc_priv * priv)1025 static inline void rx_on(struct scc_priv *priv)
1026 {
1027 unsigned long flags;
1028
1029 /* Clear RX FIFO */
1030 while (read_scc(priv, R0) & Rx_CH_AV)
1031 read_scc_data(priv);
1032 priv->rx_over = 0;
1033 if (priv->param.dma >= 0) {
1034 /* Program DMA controller */
1035 flags = claim_dma_lock();
1036 set_dma_mode(priv->param.dma, DMA_MODE_READ);
1037 set_dma_addr(priv->param.dma,
1038 (int) priv->rx_buf[priv->rx_head]);
1039 set_dma_count(priv->param.dma, BUF_SIZE);
1040 release_dma_lock(flags);
1041 enable_dma(priv->param.dma);
1042 /* Configure PackeTwin DMA */
1043 if (priv->type == TYPE_TWIN) {
1044 outb((priv->param.dma ==
1045 1) ? TWIN_DMA_HDX_R1 : TWIN_DMA_HDX_R3,
1046 priv->card_base + TWIN_DMA_CFG);
1047 }
1048 /* Sp. cond. intr. only, ext int enable, RX DMA enable */
1049 write_scc(priv, R1, EXT_INT_ENAB | INT_ERR_Rx |
1050 WT_RDY_RT | WT_FN_RDYFN | WT_RDY_ENAB);
1051 } else {
1052 /* Reset current frame */
1053 priv->rx_ptr = 0;
1054 /* Intr. on all Rx characters and Sp. cond., ext int enable */
1055 write_scc(priv, R1, EXT_INT_ENAB | INT_ALL_Rx | WT_RDY_RT |
1056 WT_FN_RDYFN);
1057 }
1058 write_scc(priv, R0, ERR_RES);
1059 write_scc(priv, R3, RxENABLE | Rx8 | RxCRC_ENAB);
1060 }
1061
1062
rx_off(struct scc_priv * priv)1063 static inline void rx_off(struct scc_priv *priv)
1064 {
1065 /* Disable receiver */
1066 write_scc(priv, R3, Rx8);
1067 /* Disable DREQ / RX interrupt */
1068 if (priv->param.dma >= 0 && priv->type == TYPE_TWIN)
1069 outb(0, priv->card_base + TWIN_DMA_CFG);
1070 else
1071 write_scc(priv, R1, EXT_INT_ENAB | WT_FN_RDYFN);
1072 /* Disable DMA */
1073 if (priv->param.dma >= 0)
1074 disable_dma(priv->param.dma);
1075 }
1076
1077
start_timer(struct scc_priv * priv,int t,int r15)1078 static void start_timer(struct scc_priv *priv, int t, int r15)
1079 {
1080 outb(priv->tmr_mode, priv->tmr_ctrl);
1081 if (t == 0) {
1082 tm_isr(priv);
1083 } else if (t > 0) {
1084 outb(t & 0xFF, priv->tmr_cnt);
1085 outb((t >> 8) & 0xFF, priv->tmr_cnt);
1086 if (priv->type != TYPE_TWIN) {
1087 write_scc(priv, R15, r15 | CTSIE);
1088 priv->rr0 |= CTS;
1089 }
1090 }
1091 }
1092
1093
random(void)1094 static inline unsigned char random(void)
1095 {
1096 /* See "Numerical Recipes in C", second edition, p. 284 */
1097 rand = rand * 1664525L + 1013904223L;
1098 return (unsigned char) (rand >> 24);
1099 }
1100
z8530_isr(struct scc_info * info)1101 static inline void z8530_isr(struct scc_info *info)
1102 {
1103 int is, i = 100;
1104
1105 while ((is = read_scc(&info->priv[0], R3)) && i--) {
1106 if (is & CHARxIP) {
1107 rx_isr(&info->priv[0]);
1108 } else if (is & CHATxIP) {
1109 tx_isr(&info->priv[0]);
1110 } else if (is & CHAEXT) {
1111 es_isr(&info->priv[0]);
1112 } else if (is & CHBRxIP) {
1113 rx_isr(&info->priv[1]);
1114 } else if (is & CHBTxIP) {
1115 tx_isr(&info->priv[1]);
1116 } else {
1117 es_isr(&info->priv[1]);
1118 }
1119 write_scc(&info->priv[0], R0, RES_H_IUS);
1120 i++;
1121 }
1122 if (i < 0) {
1123 printk(KERN_ERR "dmascc: stuck in ISR with RR3=0x%02x.\n",
1124 is);
1125 }
1126 /* Ok, no interrupts pending from this 8530. The INT line should
1127 be inactive now. */
1128 }
1129
1130
scc_isr(int irq,void * dev_id)1131 static irqreturn_t scc_isr(int irq, void *dev_id)
1132 {
1133 struct scc_info *info = dev_id;
1134
1135 spin_lock(info->priv[0].register_lock);
1136 /* At this point interrupts are enabled, and the interrupt under service
1137 is already acknowledged, but masked off.
1138
1139 Interrupt processing: We loop until we know that the IRQ line is
1140 low. If another positive edge occurs afterwards during the ISR,
1141 another interrupt will be triggered by the interrupt controller
1142 as soon as the IRQ level is enabled again (see asm/irq.h).
1143
1144 Bottom-half handlers will be processed after scc_isr(). This is
1145 important, since we only have small ringbuffers and want new data
1146 to be fetched/delivered immediately. */
1147
1148 if (info->priv[0].type == TYPE_TWIN) {
1149 int is, card_base = info->priv[0].card_base;
1150 while ((is = ~inb(card_base + TWIN_INT_REG)) &
1151 TWIN_INT_MSK) {
1152 if (is & TWIN_SCC_MSK) {
1153 z8530_isr(info);
1154 } else if (is & TWIN_TMR1_MSK) {
1155 inb(card_base + TWIN_CLR_TMR1);
1156 tm_isr(&info->priv[0]);
1157 } else {
1158 inb(card_base + TWIN_CLR_TMR2);
1159 tm_isr(&info->priv[1]);
1160 }
1161 }
1162 } else
1163 z8530_isr(info);
1164 spin_unlock(info->priv[0].register_lock);
1165 return IRQ_HANDLED;
1166 }
1167
1168
rx_isr(struct scc_priv * priv)1169 static void rx_isr(struct scc_priv *priv)
1170 {
1171 if (priv->param.dma >= 0) {
1172 /* Check special condition and perform error reset. See 2.4.7.5. */
1173 special_condition(priv, read_scc(priv, R1));
1174 write_scc(priv, R0, ERR_RES);
1175 } else {
1176 /* Check special condition for each character. Error reset not necessary.
1177 Same algorithm for SCC and ESCC. See 2.4.7.1 and 2.4.7.4. */
1178 int rc;
1179 while (read_scc(priv, R0) & Rx_CH_AV) {
1180 rc = read_scc(priv, R1);
1181 if (priv->rx_ptr < BUF_SIZE)
1182 priv->rx_buf[priv->rx_head][priv->
1183 rx_ptr++] =
1184 read_scc_data(priv);
1185 else {
1186 priv->rx_over = 2;
1187 read_scc_data(priv);
1188 }
1189 special_condition(priv, rc);
1190 }
1191 }
1192 }
1193
1194
special_condition(struct scc_priv * priv,int rc)1195 static void special_condition(struct scc_priv *priv, int rc)
1196 {
1197 int cb;
1198 unsigned long flags;
1199
1200 /* See Figure 2-15. Only overrun and EOF need to be checked. */
1201
1202 if (rc & Rx_OVR) {
1203 /* Receiver overrun */
1204 priv->rx_over = 1;
1205 if (priv->param.dma < 0)
1206 write_scc(priv, R0, ERR_RES);
1207 } else if (rc & END_FR) {
1208 /* End of frame. Get byte count */
1209 if (priv->param.dma >= 0) {
1210 flags = claim_dma_lock();
1211 cb = BUF_SIZE - get_dma_residue(priv->param.dma) -
1212 2;
1213 release_dma_lock(flags);
1214 } else {
1215 cb = priv->rx_ptr - 2;
1216 }
1217 if (priv->rx_over) {
1218 /* We had an overrun */
1219 priv->dev->stats.rx_errors++;
1220 if (priv->rx_over == 2)
1221 priv->dev->stats.rx_length_errors++;
1222 else
1223 priv->dev->stats.rx_fifo_errors++;
1224 priv->rx_over = 0;
1225 } else if (rc & CRC_ERR) {
1226 /* Count invalid CRC only if packet length >= minimum */
1227 if (cb >= 15) {
1228 priv->dev->stats.rx_errors++;
1229 priv->dev->stats.rx_crc_errors++;
1230 }
1231 } else {
1232 if (cb >= 15) {
1233 if (priv->rx_count < NUM_RX_BUF - 1) {
1234 /* Put good frame in FIFO */
1235 priv->rx_len[priv->rx_head] = cb;
1236 priv->rx_head =
1237 (priv->rx_head +
1238 1) % NUM_RX_BUF;
1239 priv->rx_count++;
1240 schedule_work(&priv->rx_work);
1241 } else {
1242 priv->dev->stats.rx_errors++;
1243 priv->dev->stats.rx_over_errors++;
1244 }
1245 }
1246 }
1247 /* Get ready for new frame */
1248 if (priv->param.dma >= 0) {
1249 flags = claim_dma_lock();
1250 set_dma_addr(priv->param.dma,
1251 (int) priv->rx_buf[priv->rx_head]);
1252 set_dma_count(priv->param.dma, BUF_SIZE);
1253 release_dma_lock(flags);
1254 } else {
1255 priv->rx_ptr = 0;
1256 }
1257 }
1258 }
1259
1260
rx_bh(struct work_struct * ugli_api)1261 static void rx_bh(struct work_struct *ugli_api)
1262 {
1263 struct scc_priv *priv = container_of(ugli_api, struct scc_priv, rx_work);
1264 int i = priv->rx_tail;
1265 int cb;
1266 unsigned long flags;
1267 struct sk_buff *skb;
1268 unsigned char *data;
1269
1270 spin_lock_irqsave(&priv->ring_lock, flags);
1271 while (priv->rx_count) {
1272 spin_unlock_irqrestore(&priv->ring_lock, flags);
1273 cb = priv->rx_len[i];
1274 /* Allocate buffer */
1275 skb = dev_alloc_skb(cb + 1);
1276 if (skb == NULL) {
1277 /* Drop packet */
1278 priv->dev->stats.rx_dropped++;
1279 } else {
1280 /* Fill buffer */
1281 data = skb_put(skb, cb + 1);
1282 data[0] = 0;
1283 memcpy(&data[1], priv->rx_buf[i], cb);
1284 skb->protocol = ax25_type_trans(skb, priv->dev);
1285 netif_rx(skb);
1286 priv->dev->stats.rx_packets++;
1287 priv->dev->stats.rx_bytes += cb;
1288 }
1289 spin_lock_irqsave(&priv->ring_lock, flags);
1290 /* Move tail */
1291 priv->rx_tail = i = (i + 1) % NUM_RX_BUF;
1292 priv->rx_count--;
1293 }
1294 spin_unlock_irqrestore(&priv->ring_lock, flags);
1295 }
1296
1297
tx_isr(struct scc_priv * priv)1298 static void tx_isr(struct scc_priv *priv)
1299 {
1300 int i = priv->tx_tail, p = priv->tx_ptr;
1301
1302 /* Suspend TX interrupts if we don't want to send anything.
1303 See Figure 2-22. */
1304 if (p == priv->tx_len[i]) {
1305 write_scc(priv, R0, RES_Tx_P);
1306 return;
1307 }
1308
1309 /* Write characters */
1310 while ((read_scc(priv, R0) & Tx_BUF_EMP) && p < priv->tx_len[i]) {
1311 write_scc_data(priv, priv->tx_buf[i][p++], 0);
1312 }
1313
1314 /* Reset EOM latch of Z8530 */
1315 if (!priv->tx_ptr && p && priv->chip == Z8530)
1316 write_scc(priv, R0, RES_EOM_L);
1317
1318 priv->tx_ptr = p;
1319 }
1320
1321
es_isr(struct scc_priv * priv)1322 static void es_isr(struct scc_priv *priv)
1323 {
1324 int i, rr0, drr0, res;
1325 unsigned long flags;
1326
1327 /* Read status, reset interrupt bit (open latches) */
1328 rr0 = read_scc(priv, R0);
1329 write_scc(priv, R0, RES_EXT_INT);
1330 drr0 = priv->rr0 ^ rr0;
1331 priv->rr0 = rr0;
1332
1333 /* Transmit underrun (2.4.9.6). We can't check the TxEOM flag, since
1334 it might have already been cleared again by AUTOEOM. */
1335 if (priv->state == TX_DATA) {
1336 /* Get remaining bytes */
1337 i = priv->tx_tail;
1338 if (priv->param.dma >= 0) {
1339 disable_dma(priv->param.dma);
1340 flags = claim_dma_lock();
1341 res = get_dma_residue(priv->param.dma);
1342 release_dma_lock(flags);
1343 } else {
1344 res = priv->tx_len[i] - priv->tx_ptr;
1345 priv->tx_ptr = 0;
1346 }
1347 /* Disable DREQ / TX interrupt */
1348 if (priv->param.dma >= 0 && priv->type == TYPE_TWIN)
1349 outb(0, priv->card_base + TWIN_DMA_CFG);
1350 else
1351 write_scc(priv, R1, EXT_INT_ENAB | WT_FN_RDYFN);
1352 if (res) {
1353 /* Update packet statistics */
1354 priv->dev->stats.tx_errors++;
1355 priv->dev->stats.tx_fifo_errors++;
1356 /* Other underrun interrupts may already be waiting */
1357 write_scc(priv, R0, RES_EXT_INT);
1358 write_scc(priv, R0, RES_EXT_INT);
1359 } else {
1360 /* Update packet statistics */
1361 priv->dev->stats.tx_packets++;
1362 priv->dev->stats.tx_bytes += priv->tx_len[i];
1363 /* Remove frame from FIFO */
1364 priv->tx_tail = (i + 1) % NUM_TX_BUF;
1365 priv->tx_count--;
1366 /* Inform upper layers */
1367 netif_wake_queue(priv->dev);
1368 }
1369 /* Switch state */
1370 write_scc(priv, R15, 0);
1371 if (priv->tx_count &&
1372 (jiffies - priv->tx_start) < priv->param.txtimeout) {
1373 priv->state = TX_PAUSE;
1374 start_timer(priv, priv->param.txpause, 0);
1375 } else {
1376 priv->state = TX_TAIL;
1377 start_timer(priv, priv->param.txtail, 0);
1378 }
1379 }
1380
1381 /* DCD transition */
1382 if (drr0 & DCD) {
1383 if (rr0 & DCD) {
1384 switch (priv->state) {
1385 case IDLE:
1386 case WAIT:
1387 priv->state = DCD_ON;
1388 write_scc(priv, R15, 0);
1389 start_timer(priv, priv->param.dcdon, 0);
1390 }
1391 } else {
1392 switch (priv->state) {
1393 case RX_ON:
1394 rx_off(priv);
1395 priv->state = DCD_OFF;
1396 write_scc(priv, R15, 0);
1397 start_timer(priv, priv->param.dcdoff, 0);
1398 }
1399 }
1400 }
1401
1402 /* CTS transition */
1403 if ((drr0 & CTS) && (~rr0 & CTS) && priv->type != TYPE_TWIN)
1404 tm_isr(priv);
1405
1406 }
1407
1408
tm_isr(struct scc_priv * priv)1409 static void tm_isr(struct scc_priv *priv)
1410 {
1411 switch (priv->state) {
1412 case TX_HEAD:
1413 case TX_PAUSE:
1414 tx_on(priv);
1415 priv->state = TX_DATA;
1416 break;
1417 case TX_TAIL:
1418 write_scc(priv, R5, TxCRC_ENAB | Tx8);
1419 priv->state = RTS_OFF;
1420 if (priv->type != TYPE_TWIN)
1421 write_scc(priv, R15, 0);
1422 start_timer(priv, priv->param.rtsoff, 0);
1423 break;
1424 case RTS_OFF:
1425 write_scc(priv, R15, DCDIE);
1426 priv->rr0 = read_scc(priv, R0);
1427 if (priv->rr0 & DCD) {
1428 priv->dev->stats.collisions++;
1429 rx_on(priv);
1430 priv->state = RX_ON;
1431 } else {
1432 priv->state = WAIT;
1433 start_timer(priv, priv->param.waittime, DCDIE);
1434 }
1435 break;
1436 case WAIT:
1437 if (priv->tx_count) {
1438 priv->state = TX_HEAD;
1439 priv->tx_start = jiffies;
1440 write_scc(priv, R5,
1441 TxCRC_ENAB | RTS | TxENAB | Tx8);
1442 write_scc(priv, R15, 0);
1443 start_timer(priv, priv->param.txdelay, 0);
1444 } else {
1445 priv->state = IDLE;
1446 if (priv->type != TYPE_TWIN)
1447 write_scc(priv, R15, DCDIE);
1448 }
1449 break;
1450 case DCD_ON:
1451 case DCD_OFF:
1452 write_scc(priv, R15, DCDIE);
1453 priv->rr0 = read_scc(priv, R0);
1454 if (priv->rr0 & DCD) {
1455 rx_on(priv);
1456 priv->state = RX_ON;
1457 } else {
1458 priv->state = WAIT;
1459 start_timer(priv,
1460 random() / priv->param.persist *
1461 priv->param.slottime, DCDIE);
1462 }
1463 break;
1464 }
1465 }
1466
