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/rtnetlink.h>
36 #include <linux/sockios.h>
37 #include <linux/workqueue.h>
38 #include <asm/atomic.h>
39 #include <asm/dma.h>
40 #include <asm/io.h>
41 #include <asm/irq.h>
42 #include <asm/uaccess.h>
43 #include <net/ax25.h>
44 #include "z8530.h"
45
46
47 /* Number of buffers per channel */
48
49 #define NUM_TX_BUF 2 /* NUM_TX_BUF >= 1 (min. 2 recommended) */
50 #define NUM_RX_BUF 6 /* NUM_RX_BUF >= 1 (min. 2 recommended) */
51 #define BUF_SIZE 1576 /* BUF_SIZE >= mtu + hard_header_len */
52
53
54 /* Cards supported */
55
56 #define HW_PI { "Ottawa PI", 0x300, 0x20, 0x10, 8, \
57 0, 8, 1843200, 3686400 }
58 #define HW_PI2 { "Ottawa PI2", 0x300, 0x20, 0x10, 8, \
59 0, 8, 3686400, 7372800 }
60 #define HW_TWIN { "Gracilis PackeTwin", 0x200, 0x10, 0x10, 32, \
61 0, 4, 6144000, 6144000 }
62 #define HW_S5 { "S5SCC/DMA", 0x200, 0x10, 0x10, 32, \
63 0, 8, 4915200, 9830400 }
64
65 #define HARDWARE { HW_PI, HW_PI2, HW_TWIN, HW_S5 }
66
67 #define TMR_0_HZ 25600 /* Frequency of timer 0 */
68
69 #define TYPE_PI 0
70 #define TYPE_PI2 1
71 #define TYPE_TWIN 2
72 #define TYPE_S5 3
73 #define NUM_TYPES 4
74
75 #define MAX_NUM_DEVS 32
76
77
78 /* SCC chips supported */
79
80 #define Z8530 0
81 #define Z85C30 1
82 #define Z85230 2
83
84 #define CHIPNAMES { "Z8530", "Z85C30", "Z85230" }
85
86
87 /* I/O registers */
88
89 /* 8530 registers relative to card base */
90 #define SCCB_CMD 0x00
91 #define SCCB_DATA 0x01
92 #define SCCA_CMD 0x02
93 #define SCCA_DATA 0x03
94
95 /* 8253/8254 registers relative to card base */
96 #define TMR_CNT0 0x00
97 #define TMR_CNT1 0x01
98 #define TMR_CNT2 0x02
99 #define TMR_CTRL 0x03
100
101 /* Additional PI/PI2 registers relative to card base */
102 #define PI_DREQ_MASK 0x04
103
104 /* Additional PackeTwin registers relative to card base */
105 #define TWIN_INT_REG 0x08
106 #define TWIN_CLR_TMR1 0x09
107 #define TWIN_CLR_TMR2 0x0a
108 #define TWIN_SPARE_1 0x0b
109 #define TWIN_DMA_CFG 0x08
110 #define TWIN_SERIAL_CFG 0x09
111 #define TWIN_DMA_CLR_FF 0x0a
112 #define TWIN_SPARE_2 0x0b
113
114
115 /* PackeTwin I/O register values */
116
117 /* INT_REG */
118 #define TWIN_SCC_MSK 0x01
119 #define TWIN_TMR1_MSK 0x02
120 #define TWIN_TMR2_MSK 0x04
121 #define TWIN_INT_MSK 0x07
122
123 /* SERIAL_CFG */
124 #define TWIN_DTRA_ON 0x01
125 #define TWIN_DTRB_ON 0x02
126 #define TWIN_EXTCLKA 0x04
127 #define TWIN_EXTCLKB 0x08
128 #define TWIN_LOOPA_ON 0x10
129 #define TWIN_LOOPB_ON 0x20
130 #define TWIN_EI 0x80
131
132 /* DMA_CFG */
133 #define TWIN_DMA_HDX_T1 0x08
134 #define TWIN_DMA_HDX_R1 0x0a
135 #define TWIN_DMA_HDX_T3 0x14
136 #define TWIN_DMA_HDX_R3 0x16
137 #define TWIN_DMA_FDX_T3R1 0x1b
138 #define TWIN_DMA_FDX_T1R3 0x1d
139
140
141 /* Status values */
142
143 #define IDLE 0
144 #define TX_HEAD 1
145 #define TX_DATA 2
146 #define TX_PAUSE 3
147 #define TX_TAIL 4
148 #define RTS_OFF 5
149 #define WAIT 6
150 #define DCD_ON 7
151 #define RX_ON 8
152 #define DCD_OFF 9
153
154
155 /* Ioctls */
156
157 #define SIOCGSCCPARAM SIOCDEVPRIVATE
158 #define SIOCSSCCPARAM (SIOCDEVPRIVATE+1)
159
160
161 /* Data types */
162
163 struct scc_param {
164 int pclk_hz; /* frequency of BRG input (don't change) */
165 int brg_tc; /* BRG terminal count; BRG disabled if < 0 */
166 int nrzi; /* 0 (nrz), 1 (nrzi) */
167 int clocks; /* see dmascc_cfg documentation */
168 int txdelay; /* [1/TMR_0_HZ] */
169 int txtimeout; /* [1/HZ] */
170 int txtail; /* [1/TMR_0_HZ] */
171 int waittime; /* [1/TMR_0_HZ] */
172 int slottime; /* [1/TMR_0_HZ] */
173 int persist; /* 1 ... 256 */
174 int dma; /* -1 (disable), 0, 1, 3 */
175 int txpause; /* [1/TMR_0_HZ] */
176 int rtsoff; /* [1/TMR_0_HZ] */
177 int dcdon; /* [1/TMR_0_HZ] */
178 int dcdoff; /* [1/TMR_0_HZ] */
179 };
180
181 struct scc_hardware {
182 char *name;
183 int io_region;
184 int io_delta;
185 int io_size;
186 int num_devs;
187 int scc_offset;
188 int tmr_offset;
189 int tmr_hz;
190 int pclk_hz;
191 };
192
193 struct scc_priv {
194 int type;
195 int chip;
196 struct net_device *dev;
197 struct scc_info *info;
198 struct net_device_stats stats;
199 int channel;
200 int card_base, scc_cmd, scc_data;
201 int tmr_cnt, tmr_ctrl, tmr_mode;
202 struct scc_param param;
203 char rx_buf[NUM_RX_BUF][BUF_SIZE];
204 int rx_len[NUM_RX_BUF];
205 int rx_ptr;
206 struct work_struct rx_work;
207 int rx_head, rx_tail, rx_count;
208 int rx_over;
209 char tx_buf[NUM_TX_BUF][BUF_SIZE];
210 int tx_len[NUM_TX_BUF];
211 int tx_ptr;
212 int tx_head, tx_tail, tx_count;
213 int state;
214 unsigned long tx_start;
215 int rr0;
216 spinlock_t *register_lock; /* Per scc_info */
217 spinlock_t ring_lock;
218 };
219
220 struct scc_info {
221 int irq_used;
222 int twin_serial_cfg;
223 struct net_device *dev[2];
224 struct scc_priv priv[2];
225 struct scc_info *next;
226 spinlock_t register_lock; /* Per device register lock */
227 };
228
229
230 /* Function declarations */
231 static int setup_adapter(int card_base, int type, int n) __init;
232
233 static void write_scc(struct scc_priv *priv, int reg, int val);
234 static void write_scc_data(struct scc_priv *priv, int val, int fast);
235 static int read_scc(struct scc_priv *priv, int reg);
236 static int read_scc_data(struct scc_priv *priv);
237
238 static int scc_open(struct net_device *dev);
239 static int scc_close(struct net_device *dev);
240 static int scc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
241 static int scc_send_packet(struct sk_buff *skb, struct net_device *dev);
242 static struct net_device_stats *scc_get_stats(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_array(io, int, 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
setup_adapter(int card_base,int type,int n)444 static int __init setup_adapter(int card_base, int type, int n)
445 {
446 int i, irq, chip;
447 struct scc_info *info;
448 struct net_device *dev;
449 struct scc_priv *priv;
450 unsigned long time;
451 unsigned int irqs;
452 int tmr_base = card_base + hw[type].tmr_offset;
453 int scc_base = card_base + hw[type].scc_offset;
454 char *chipnames[] = CHIPNAMES;
455
456 /* Initialize what is necessary for write_scc and write_scc_data */
457 info = kzalloc(sizeof(struct scc_info), GFP_KERNEL | GFP_DMA);
458 if (!info) {
459 printk(KERN_ERR "dmascc: "
460 "could not allocate memory for %s at %#3x\n",
461 hw[type].name, card_base);
462 goto out;
463 }
464
465
466 info->dev[0] = alloc_netdev(0, "", dev_setup);
467 if (!info->dev[0]) {
468 printk(KERN_ERR "dmascc: "
469 "could not allocate memory for %s at %#3x\n",
470 hw[type].name, card_base);
471 goto out1;
472 }
473
474 info->dev[1] = alloc_netdev(0, "", dev_setup);
475 if (!info->dev[1]) {
476 printk(KERN_ERR "dmascc: "
477 "could not allocate memory for %s at %#3x\n",
478 hw[type].name, card_base);
479 goto out2;
480 }
481 spin_lock_init(&info->register_lock);
482
483 priv = &info->priv[0];
484 priv->type = type;
485 priv->card_base = card_base;
486 priv->scc_cmd = scc_base + SCCA_CMD;
487 priv->scc_data = scc_base + SCCA_DATA;
488 priv->register_lock = &info->register_lock;
489
490 /* Reset SCC */
491 write_scc(priv, R9, FHWRES | MIE | NV);
492
493 /* Determine type of chip by enabling SDLC/HDLC enhancements */
494 write_scc(priv, R15, SHDLCE);
495 if (!read_scc(priv, R15)) {
496 /* WR7' not present. This is an ordinary Z8530 SCC. */
497 chip = Z8530;
498 } else {
499 /* Put one character in TX FIFO */
500 write_scc_data(priv, 0, 0);
501 if (read_scc(priv, R0) & Tx_BUF_EMP) {
502 /* TX FIFO not full. This is a Z85230 ESCC with a 4-byte FIFO. */
503 chip = Z85230;
504 } else {
505 /* TX FIFO full. This is a Z85C30 SCC with a 1-byte FIFO. */
506 chip = Z85C30;
507 }
508 }
509 write_scc(priv, R15, 0);
510
511 /* Start IRQ auto-detection */
512 irqs = probe_irq_on();
513
514 /* Enable interrupts */
515 if (type == TYPE_TWIN) {
516 outb(0, card_base + TWIN_DMA_CFG);
517 inb(card_base + TWIN_CLR_TMR1);
518 inb(card_base + TWIN_CLR_TMR2);
519 info->twin_serial_cfg = TWIN_EI;
520 outb(info->twin_serial_cfg, card_base + TWIN_SERIAL_CFG);
521 } else {
522 write_scc(priv, R15, CTSIE);
523 write_scc(priv, R0, RES_EXT_INT);
524 write_scc(priv, R1, EXT_INT_ENAB);
525 }
526
527 /* Start timer */
528 outb(1, tmr_base + TMR_CNT1);
529 outb(0, tmr_base + TMR_CNT1);
530
531 /* Wait and detect IRQ */
532 time = jiffies;
533 while (jiffies - time < 2 + HZ / TMR_0_HZ);
534 irq = probe_irq_off(irqs);
535
536 /* Clear pending interrupt, disable interrupts */
537 if (type == TYPE_TWIN) {
538 inb(card_base + TWIN_CLR_TMR1);
539 } else {
540 write_scc(priv, R1, 0);
541 write_scc(priv, R15, 0);
542 write_scc(priv, R0, RES_EXT_INT);
543 }
544
545 if (irq <= 0) {
546 printk(KERN_ERR
547 "dmascc: could not find irq of %s at %#3x (irq=%d)\n",
548 hw[type].name, card_base, irq);
549 goto out3;
550 }
551
552 /* Set up data structures */
553 for (i = 0; i < 2; i++) {
554 dev = info->dev[i];
555 priv = &info->priv[i];
556 priv->type = type;
557 priv->chip = chip;
558 priv->dev = dev;
559 priv->info = info;
560 priv->channel = i;
561 spin_lock_init(&priv->ring_lock);
562 priv->register_lock = &info->register_lock;
563 priv->card_base = card_base;
564 priv->scc_cmd = scc_base + (i ? SCCB_CMD : SCCA_CMD);
565 priv->scc_data = scc_base + (i ? SCCB_DATA : SCCA_DATA);
566 priv->tmr_cnt = tmr_base + (i ? TMR_CNT2 : TMR_CNT1);
567 priv->tmr_ctrl = tmr_base + TMR_CTRL;
568 priv->tmr_mode = i ? 0xb0 : 0x70;
569 priv->param.pclk_hz = hw[type].pclk_hz;
570 priv->param.brg_tc = -1;
571 priv->param.clocks = TCTRxCP | RCRTxCP;
572 priv->param.persist = 256;
573 priv->param.dma = -1;
574 INIT_WORK(&priv->rx_work, rx_bh);
575 dev->ml_priv = priv;
576 sprintf(dev->name, "dmascc%i", 2 * n + i);
577 dev->base_addr = card_base;
578 dev->irq = irq;
579 dev->open = scc_open;
580 dev->stop = scc_close;
581 dev->do_ioctl = scc_ioctl;
582 dev->hard_start_xmit = scc_send_packet;
583 dev->get_stats = scc_get_stats;
584 dev->header_ops = &ax25_header_ops;
585 dev->set_mac_address = scc_set_mac_address;
586 }
587 if (register_netdev(info->dev[0])) {
588 printk(KERN_ERR "dmascc: could not register %s\n",
589 info->dev[0]->name);
590 goto out3;
591 }
592 if (register_netdev(info->dev[1])) {
593 printk(KERN_ERR "dmascc: could not register %s\n",
594 info->dev[1]->name);
595 goto out4;
596 }
597
598
599 info->next = first;
600 first = info;
601 printk(KERN_INFO "dmascc: found %s (%s) at %#3x, irq %d\n",
602 hw[type].name, chipnames[chip], card_base, irq);
603 return 0;
604
605 out4:
606 unregister_netdev(info->dev[0]);
607 out3:
608 if (info->priv[0].type == TYPE_TWIN)
609 outb(0, info->dev[0]->base_addr + TWIN_SERIAL_CFG);
610 write_scc(&info->priv[0], R9, FHWRES);
611 free_netdev(info->dev[1]);
612 out2:
613 free_netdev(info->dev[0]);
614 out1:
615 kfree(info);
616 out:
617 return -1;
618 }
619
620
621 /* Driver functions */
622
write_scc(struct scc_priv * priv,int reg,int val)623 static void write_scc(struct scc_priv *priv, int reg, int val)
624 {
625 unsigned long flags;
626 switch (priv->type) {
627 case TYPE_S5:
628 if (reg)
629 outb(reg, priv->scc_cmd);
630 outb(val, priv->scc_cmd);
631 return;
632 case TYPE_TWIN:
633 if (reg)
634 outb_p(reg, priv->scc_cmd);
635 outb_p(val, priv->scc_cmd);
636 return;
637 default:
638 spin_lock_irqsave(priv->register_lock, flags);
639 outb_p(0, priv->card_base + PI_DREQ_MASK);
640 if (reg)
641 outb_p(reg, priv->scc_cmd);
642 outb_p(val, priv->scc_cmd);
643 outb(1, priv->card_base + PI_DREQ_MASK);
644 spin_unlock_irqrestore(priv->register_lock, flags);
645 return;
646 }
647 }
648
649
write_scc_data(struct scc_priv * priv,int val,int fast)650 static void write_scc_data(struct scc_priv *priv, int val, int fast)
651 {
652 unsigned long flags;
653 switch (priv->type) {
654 case TYPE_S5:
655 outb(val, priv->scc_data);
656 return;
657 case TYPE_TWIN:
658 outb_p(val, priv->scc_data);
659 return;
660 default:
661 if (fast)
662 outb_p(val, priv->scc_data);
663 else {
664 spin_lock_irqsave(priv->register_lock, flags);
665 outb_p(0, priv->card_base + PI_DREQ_MASK);
666 outb_p(val, priv->scc_data);
667 outb(1, priv->card_base + PI_DREQ_MASK);
668 spin_unlock_irqrestore(priv->register_lock, flags);
669 }
670 return;
671 }
672 }
673
674
read_scc(struct scc_priv * priv,int reg)675 static int read_scc(struct scc_priv *priv, int reg)
676 {
677 int rc;
678 unsigned long flags;
679 switch (priv->type) {
680 case TYPE_S5:
681 if (reg)
682 outb(reg, priv->scc_cmd);
683 return inb(priv->scc_cmd);
684 case TYPE_TWIN:
685 if (reg)
686 outb_p(reg, priv->scc_cmd);
687 return inb_p(priv->scc_cmd);
688 default:
689 spin_lock_irqsave(priv->register_lock, flags);
690 outb_p(0, priv->card_base + PI_DREQ_MASK);
691 if (reg)
692 outb_p(reg, priv->scc_cmd);
693 rc = inb_p(priv->scc_cmd);
694 outb(1, priv->card_base + PI_DREQ_MASK);
695 spin_unlock_irqrestore(priv->register_lock, flags);
696 return rc;
697 }
698 }
699
700
read_scc_data(struct scc_priv * priv)701 static int read_scc_data(struct scc_priv *priv)
702 {
703 int rc;
704 unsigned long flags;
705 switch (priv->type) {
706 case TYPE_S5:
707 return inb(priv->scc_data);
708 case TYPE_TWIN:
709 return inb_p(priv->scc_data);
710 default:
711 spin_lock_irqsave(priv->register_lock, flags);
712 outb_p(0, priv->card_base + PI_DREQ_MASK);
713 rc = inb_p(priv->scc_data);
714 outb(1, priv->card_base + PI_DREQ_MASK);
715 spin_unlock_irqrestore(priv->register_lock, flags);
716 return rc;
717 }
718 }
719
720
scc_open(struct net_device * dev)721 static int scc_open(struct net_device *dev)
722 {
723 struct scc_priv *priv = dev->ml_priv;
724 struct scc_info *info = priv->info;
725 int card_base = priv->card_base;
726
727 /* Request IRQ if not already used by other channel */
728 if (!info->irq_used) {
729 if (request_irq(dev->irq, scc_isr, 0, "dmascc", info)) {
730 return -EAGAIN;
731 }
732 }
733 info->irq_used++;
734
735 /* Request DMA if required */
736 if (priv->param.dma >= 0) {
737 if (request_dma(priv->param.dma, "dmascc")) {
738 if (--info->irq_used == 0)
739 free_irq(dev->irq, info);
740 return -EAGAIN;
741 } else {
742 unsigned long flags = claim_dma_lock();
743 clear_dma_ff(priv->param.dma);
744 release_dma_lock(flags);
745 }
746 }
747
748 /* Initialize local variables */
749 priv->rx_ptr = 0;
750 priv->rx_over = 0;
751 priv->rx_head = priv->rx_tail = priv->rx_count = 0;
752 priv->state = IDLE;
753 priv->tx_head = priv->tx_tail = priv->tx_count = 0;
754 priv->tx_ptr = 0;
755
756 /* Reset channel */
757 write_scc(priv, R9, (priv->channel ? CHRB : CHRA) | MIE | NV);
758 /* X1 clock, SDLC mode */
759 write_scc(priv, R4, SDLC | X1CLK);
760 /* DMA */
761 write_scc(priv, R1, EXT_INT_ENAB | WT_FN_RDYFN);
762 /* 8 bit RX char, RX disable */
763 write_scc(priv, R3, Rx8);
764 /* 8 bit TX char, TX disable */
765 write_scc(priv, R5, Tx8);
766 /* SDLC address field */
767 write_scc(priv, R6, 0);
768 /* SDLC flag */
769 write_scc(priv, R7, FLAG);
770 switch (priv->chip) {
771 case Z85C30:
772 /* Select WR7' */
773 write_scc(priv, R15, SHDLCE);
774 /* Auto EOM reset */
775 write_scc(priv, R7, AUTOEOM);
776 write_scc(priv, R15, 0);
777 break;
778 case Z85230:
779 /* Select WR7' */
780 write_scc(priv, R15, SHDLCE);
781 /* The following bits are set (see 2.5.2.1):
782 - Automatic EOM reset
783 - Interrupt request if RX FIFO is half full
784 This bit should be ignored in DMA mode (according to the
785 documentation), but actually isn't. The receiver doesn't work if
786 it is set. Thus, we have to clear it in DMA mode.
787 - Interrupt/DMA request if TX FIFO is completely empty
788 a) If set, the ESCC behaves as if it had no TX FIFO (Z85C30
789 compatibility).
790 b) If cleared, DMA requests may follow each other very quickly,
791 filling up the TX FIFO.
792 Advantage: TX works even in case of high bus latency.
793 Disadvantage: Edge-triggered DMA request circuitry may miss
794 a request. No more data is delivered, resulting
795 in a TX FIFO underrun.
796 Both PI2 and S5SCC/DMA seem to work fine with TXFIFOE cleared.
797 The PackeTwin doesn't. I don't know about the PI, but let's
798 assume it behaves like the PI2.
799 */
800 if (priv->param.dma >= 0) {
801 if (priv->type == TYPE_TWIN)
802 write_scc(priv, R7, AUTOEOM | TXFIFOE);
803 else
804 write_scc(priv, R7, AUTOEOM);
805 } else {
806 write_scc(priv, R7, AUTOEOM | RXFIFOH);
807 }
808 write_scc(priv, R15, 0);
809 break;
810 }
811 /* Preset CRC, NRZ(I) encoding */
812 write_scc(priv, R10, CRCPS | (priv->param.nrzi ? NRZI : NRZ));
813
814 /* Configure baud rate generator */
815 if (priv->param.brg_tc >= 0) {
816 /* Program BR generator */
817 write_scc(priv, R12, priv->param.brg_tc & 0xFF);
818 write_scc(priv, R13, (priv->param.brg_tc >> 8) & 0xFF);
819 /* BRG source = SYS CLK; enable BRG; DTR REQ function (required by
820 PackeTwin, not connected on the PI2); set DPLL source to BRG */
821 write_scc(priv, R14, SSBR | DTRREQ | BRSRC | BRENABL);
822 /* Enable DPLL */
823 write_scc(priv, R14, SEARCH | DTRREQ | BRSRC | BRENABL);
824 } else {
825 /* Disable BR generator */
826 write_scc(priv, R14, DTRREQ | BRSRC);
827 }
828
829 /* Configure clocks */
830 if (priv->type == TYPE_TWIN) {
831 /* Disable external TX clock receiver */
832 outb((info->twin_serial_cfg &=
833 ~(priv->channel ? TWIN_EXTCLKB : TWIN_EXTCLKA)),
834 card_base + TWIN_SERIAL_CFG);
835 }
836 write_scc(priv, R11, priv->param.clocks);
837 if ((priv->type == TYPE_TWIN) && !(priv->param.clocks & TRxCOI)) {
838 /* Enable external TX clock receiver */
839 outb((info->twin_serial_cfg |=
840 (priv->channel ? TWIN_EXTCLKB : TWIN_EXTCLKA)),
841 card_base + TWIN_SERIAL_CFG);
842 }
843
844 /* Configure PackeTwin */
845 if (priv->type == TYPE_TWIN) {
846 /* Assert DTR, enable interrupts */
847 outb((info->twin_serial_cfg |= TWIN_EI |
848 (priv->channel ? TWIN_DTRB_ON : TWIN_DTRA_ON)),
849 card_base + TWIN_SERIAL_CFG);
850 }
851
852 /* Read current status */
853 priv->rr0 = read_scc(priv, R0);
854 /* Enable DCD interrupt */
855 write_scc(priv, R15, DCDIE);
856
857 netif_start_queue(dev);
858
859 return 0;
860 }
861
862
scc_close(struct net_device * dev)863 static int scc_close(struct net_device *dev)
864 {
865 struct scc_priv *priv = dev->ml_priv;
866 struct scc_info *info = priv->info;
867 int card_base = priv->card_base;
868
869 netif_stop_queue(dev);
870
871 if (priv->type == TYPE_TWIN) {
872 /* Drop DTR */
873 outb((info->twin_serial_cfg &=
874 (priv->channel ? ~TWIN_DTRB_ON : ~TWIN_DTRA_ON)),
875 card_base + TWIN_SERIAL_CFG);
876 }
877
878 /* Reset channel, free DMA and IRQ */
879 write_scc(priv, R9, (priv->channel ? CHRB : CHRA) | MIE | NV);
880 if (priv->param.dma >= 0) {
881 if (priv->type == TYPE_TWIN)
882 outb(0, card_base + TWIN_DMA_CFG);
883 free_dma(priv->param.dma);
884 }
885 if (--info->irq_used == 0)
886 free_irq(dev->irq, info);
887
888 return 0;
889 }
890
891
scc_ioctl(struct net_device * dev,struct ifreq * ifr,int cmd)892 static int scc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
893 {
894 struct scc_priv *priv = dev->ml_priv;
895
896 switch (cmd) {
897 case SIOCGSCCPARAM:
898 if (copy_to_user
899 (ifr->ifr_data, &priv->param,
900 sizeof(struct scc_param)))
901 return -EFAULT;
902 return 0;
903 case SIOCSSCCPARAM:
904 if (!capable(CAP_NET_ADMIN))
905 return -EPERM;
906 if (netif_running(dev))
907 return -EAGAIN;
908 if (copy_from_user
909 (&priv->param, ifr->ifr_data,
910 sizeof(struct scc_param)))
911 return -EFAULT;
912 return 0;
913 default:
914 return -EINVAL;
915 }
916 }
917
918
scc_send_packet(struct sk_buff * skb,struct net_device * dev)919 static int scc_send_packet(struct sk_buff *skb, struct net_device *dev)
920 {
921 struct scc_priv *priv = dev->ml_priv;
922 unsigned long flags;
923 int i;
924
925 /* Temporarily stop the scheduler feeding us packets */
926 netif_stop_queue(dev);
927
928 /* Transfer data to DMA buffer */
929 i = priv->tx_head;
930 skb_copy_from_linear_data_offset(skb, 1, priv->tx_buf[i], skb->len - 1);
931 priv->tx_len[i] = skb->len - 1;
932
933 /* Clear interrupts while we touch our circular buffers */
934
935 spin_lock_irqsave(&priv->ring_lock, flags);
936 /* Move the ring buffer's head */
937 priv->tx_head = (i + 1) % NUM_TX_BUF;
938 priv->tx_count++;
939
940 /* If we just filled up the last buffer, leave queue stopped.
941 The higher layers must wait until we have a DMA buffer
942 to accept the data. */
943 if (priv->tx_count < NUM_TX_BUF)
944 netif_wake_queue(dev);
945
946 /* Set new TX state */
947 if (priv->state == IDLE) {
948 /* Assert RTS, start timer */
949 priv->state = TX_HEAD;
950 priv->tx_start = jiffies;
951 write_scc(priv, R5, TxCRC_ENAB | RTS | TxENAB | Tx8);
952 write_scc(priv, R15, 0);
953 start_timer(priv, priv->param.txdelay, 0);
954 }
955
956 /* Turn interrupts back on and free buffer */
957 spin_unlock_irqrestore(&priv->ring_lock, flags);
958 dev_kfree_skb(skb);
959
960 return 0;
961 }
962
963
scc_get_stats(struct net_device * dev)964 static struct net_device_stats *scc_get_stats(struct net_device *dev)
965 {
966 struct scc_priv *priv = dev->ml_priv;
967
968 return &priv->stats;
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->stats.rx_errors++;
1220 if (priv->rx_over == 2)
1221 priv->stats.rx_length_errors++;
1222 else
1223 priv->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->stats.rx_errors++;
1229 priv->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->stats.rx_errors++;
1243 priv->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->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->stats.rx_packets++;
1287 priv->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->stats.tx_errors++;
1355 priv->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->stats.tx_packets++;
1362 priv->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->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