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22#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
24#include <linux/module.h>
25#include <linux/errno.h>
26#include <linux/kernel.h>
27#include <linux/init.h>
28#include <linux/i2c.h>
29#include <linux/pci.h>
30#include <linux/platform_device.h>
31#include <linux/delay.h>
32#include <linux/mutex.h>
33#include <linux/slab.h>
34#include <linux/io.h>
35
36#include <linux/scx200.h>
37
38MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
39MODULE_DESCRIPTION("NatSemi SCx200 ACCESS.bus Driver");
40MODULE_ALIAS("platform:cs5535-smb");
41MODULE_LICENSE("GPL");
42
43#define MAX_DEVICES 4
44static int base[MAX_DEVICES] = { 0x820, 0x840 };
45module_param_array(base, int, NULL, 0);
46MODULE_PARM_DESC(base, "Base addresses for the ACCESS.bus controllers");
47
48#define POLL_TIMEOUT (HZ/5)
49
50enum scx200_acb_state {
51 state_idle,
52 state_address,
53 state_command,
54 state_repeat_start,
55 state_quick,
56 state_read,
57 state_write,
58};
59
60static const char *scx200_acb_state_name[] = {
61 "idle",
62 "address",
63 "command",
64 "repeat_start",
65 "quick",
66 "read",
67 "write",
68};
69
70
71struct scx200_acb_iface {
72 struct scx200_acb_iface *next;
73 struct i2c_adapter adapter;
74 unsigned base;
75 struct mutex mutex;
76
77
78 enum scx200_acb_state state;
79 int result;
80 u8 address_byte;
81 u8 command;
82 u8 *ptr;
83 char needs_reset;
84 unsigned len;
85};
86
87
88#define ACBSDA (iface->base + 0)
89#define ACBST (iface->base + 1)
90#define ACBST_SDAST 0x40
91#define ACBST_BER 0x20
92#define ACBST_NEGACK 0x10
93#define ACBST_STASTR 0x08
94#define ACBST_MASTER 0x02
95#define ACBCST (iface->base + 2)
96#define ACBCST_BB 0x02
97#define ACBCTL1 (iface->base + 3)
98#define ACBCTL1_STASTRE 0x80
99#define ACBCTL1_NMINTE 0x40
100#define ACBCTL1_ACK 0x10
101#define ACBCTL1_STOP 0x02
102#define ACBCTL1_START 0x01
103#define ACBADDR (iface->base + 4)
104#define ACBCTL2 (iface->base + 5)
105#define ACBCTL2_ENABLE 0x01
106
107
108
109static void scx200_acb_machine(struct scx200_acb_iface *iface, u8 status)
110{
111 const char *errmsg;
112
113 dev_dbg(&iface->adapter.dev, "state %s, status = 0x%02x\n",
114 scx200_acb_state_name[iface->state], status);
115
116 if (status & ACBST_BER) {
117 errmsg = "bus error";
118 goto error;
119 }
120 if (!(status & ACBST_MASTER)) {
121 errmsg = "not master";
122 goto error;
123 }
124 if (status & ACBST_NEGACK) {
125 dev_dbg(&iface->adapter.dev, "negative ack in state %s\n",
126 scx200_acb_state_name[iface->state]);
127
128 iface->state = state_idle;
129 iface->result = -ENXIO;
130
131 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
132 outb(ACBST_STASTR | ACBST_NEGACK, ACBST);
133
134
135 outb(0, ACBST);
136 return;
137 }
138
139 switch (iface->state) {
140 case state_idle:
141 dev_warn(&iface->adapter.dev, "interrupt in idle state\n");
142 break;
143
144 case state_address:
145
146 outb(iface->address_byte & ~1, ACBSDA);
147
148 iface->state = state_command;
149 break;
150
151 case state_command:
152 outb(iface->command, ACBSDA);
153
154 if (iface->address_byte & 1)
155 iface->state = state_repeat_start;
156 else
157 iface->state = state_write;
158 break;
159
160 case state_repeat_start:
161 outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
162
163
164 case state_quick:
165 if (iface->address_byte & 1) {
166 if (iface->len == 1)
167 outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
168 else
169 outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
170 outb(iface->address_byte, ACBSDA);
171
172 iface->state = state_read;
173 } else {
174 outb(iface->address_byte, ACBSDA);
175
176 iface->state = state_write;
177 }
178 break;
179
180 case state_read:
181
182 if (iface->len == 2)
183 outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
184 else
185 outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
186
187 if (iface->len == 1) {
188 iface->result = 0;
189 iface->state = state_idle;
190 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
191 }
192
193 *iface->ptr++ = inb(ACBSDA);
194 --iface->len;
195
196 break;
197
198 case state_write:
199 if (iface->len == 0) {
200 iface->result = 0;
201 iface->state = state_idle;
202 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
203 break;
204 }
205
206 outb(*iface->ptr++, ACBSDA);
207 --iface->len;
208
209 break;
210 }
211
212 return;
213
214 error:
215 dev_err(&iface->adapter.dev,
216 "%s in state %s (addr=0x%02x, len=%d, status=0x%02x)\n", errmsg,
217 scx200_acb_state_name[iface->state], iface->address_byte,
218 iface->len, status);
219
220 iface->state = state_idle;
221 iface->result = -EIO;
222 iface->needs_reset = 1;
223}
224
225static void scx200_acb_poll(struct scx200_acb_iface *iface)
226{
227 u8 status;
228 unsigned long timeout;
229
230 timeout = jiffies + POLL_TIMEOUT;
231 while (1) {
232 status = inb(ACBST);
233
234
235 outb(0, ACBST);
236
237 if ((status & (ACBST_SDAST|ACBST_BER|ACBST_NEGACK)) != 0) {
238 scx200_acb_machine(iface, status);
239 return;
240 }
241 if (time_after(jiffies, timeout))
242 break;
243 cpu_relax();
244 cond_resched();
245 }
246
247 dev_err(&iface->adapter.dev, "timeout in state %s\n",
248 scx200_acb_state_name[iface->state]);
249
250 iface->state = state_idle;
251 iface->result = -EIO;
252 iface->needs_reset = 1;
253}
254
255static void scx200_acb_reset(struct scx200_acb_iface *iface)
256{
257
258
259 outb(0x70, ACBCTL2);
260
261 outb(0, ACBCTL1);
262
263 outb(0, ACBADDR);
264
265 outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
266
267 outb(inb(ACBCTL1) & ~(ACBCTL1_STASTRE | ACBCTL1_NMINTE), ACBCTL1);
268
269 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
270
271 outb(ACBST_BER | ACBST_NEGACK | ACBST_STASTR, ACBST);
272
273 outb(inb(ACBCST) | ACBCST_BB, ACBCST);
274}
275
276static s32 scx200_acb_smbus_xfer(struct i2c_adapter *adapter,
277 u16 address, unsigned short flags,
278 char rw, u8 command, int size,
279 union i2c_smbus_data *data)
280{
281 struct scx200_acb_iface *iface = i2c_get_adapdata(adapter);
282 int len;
283 u8 *buffer;
284 u16 cur_word;
285 int rc;
286
287 switch (size) {
288 case I2C_SMBUS_QUICK:
289 len = 0;
290 buffer = NULL;
291 break;
292
293 case I2C_SMBUS_BYTE:
294 len = 1;
295 buffer = rw ? &data->byte : &command;
296 break;
297
298 case I2C_SMBUS_BYTE_DATA:
299 len = 1;
300 buffer = &data->byte;
301 break;
302
303 case I2C_SMBUS_WORD_DATA:
304 len = 2;
305 cur_word = cpu_to_le16(data->word);
306 buffer = (u8 *)&cur_word;
307 break;
308
309 case I2C_SMBUS_I2C_BLOCK_DATA:
310 len = data->block[0];
311 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
312 return -EINVAL;
313 buffer = &data->block[1];
314 break;
315
316 default:
317 return -EINVAL;
318 }
319
320 dev_dbg(&adapter->dev,
321 "size=%d, address=0x%x, command=0x%x, len=%d, read=%d\n",
322 size, address, command, len, rw);
323
324 if (!len && rw == I2C_SMBUS_READ) {
325 dev_dbg(&adapter->dev, "zero length read\n");
326 return -EINVAL;
327 }
328
329 mutex_lock(&iface->mutex);
330
331 iface->address_byte = (address << 1) | rw;
332 iface->command = command;
333 iface->ptr = buffer;
334 iface->len = len;
335 iface->result = -EINVAL;
336 iface->needs_reset = 0;
337
338 outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
339
340 if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE)
341 iface->state = state_quick;
342 else
343 iface->state = state_address;
344
345 while (iface->state != state_idle)
346 scx200_acb_poll(iface);
347
348 if (iface->needs_reset)
349 scx200_acb_reset(iface);
350
351 rc = iface->result;
352
353 mutex_unlock(&iface->mutex);
354
355 if (rc == 0 && size == I2C_SMBUS_WORD_DATA && rw == I2C_SMBUS_READ)
356 data->word = le16_to_cpu(cur_word);
357
358#ifdef DEBUG
359 dev_dbg(&adapter->dev, "transfer done, result: %d", rc);
360 if (buffer) {
361 int i;
362 printk(" data:");
363 for (i = 0; i < len; ++i)
364 printk(" %02x", buffer[i]);
365 }
366 printk("\n");
367#endif
368
369 return rc;
370}
371
372static u32 scx200_acb_func(struct i2c_adapter *adapter)
373{
374 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
375 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
376 I2C_FUNC_SMBUS_I2C_BLOCK;
377}
378
379
380static const struct i2c_algorithm scx200_acb_algorithm = {
381 .smbus_xfer = scx200_acb_smbus_xfer,
382 .functionality = scx200_acb_func,
383};
384
385static struct scx200_acb_iface *scx200_acb_list;
386static DEFINE_MUTEX(scx200_acb_list_mutex);
387
388static int scx200_acb_probe(struct scx200_acb_iface *iface)
389{
390 u8 val;
391
392
393
394 outb(0x70, ACBCTL2);
395
396 if (inb(ACBCTL2) != 0x70) {
397 pr_debug("ACBCTL2 readback failed\n");
398 return -ENXIO;
399 }
400
401 outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
402
403 val = inb(ACBCTL1);
404 if (val) {
405 pr_debug("disabled, but ACBCTL1=0x%02x\n", val);
406 return -ENXIO;
407 }
408
409 outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
410
411 outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
412
413 val = inb(ACBCTL1);
414 if ((val & ACBCTL1_NMINTE) != ACBCTL1_NMINTE) {
415 pr_debug("enabled, but NMINTE won't be set, ACBCTL1=0x%02x\n",
416 val);
417 return -ENXIO;
418 }
419
420 return 0;
421}
422
423static struct scx200_acb_iface *scx200_create_iface(const char *text,
424 struct device *dev, int index)
425{
426 struct scx200_acb_iface *iface;
427 struct i2c_adapter *adapter;
428
429 iface = kzalloc(sizeof(*iface), GFP_KERNEL);
430 if (!iface) {
431 pr_err("can't allocate memory\n");
432 return NULL;
433 }
434
435 adapter = &iface->adapter;
436 i2c_set_adapdata(adapter, iface);
437 snprintf(adapter->name, sizeof(adapter->name), "%s ACB%d", text, index);
438 adapter->owner = THIS_MODULE;
439 adapter->algo = &scx200_acb_algorithm;
440 adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
441 adapter->dev.parent = dev;
442
443 mutex_init(&iface->mutex);
444
445 return iface;
446}
447
448static int scx200_acb_create(struct scx200_acb_iface *iface)
449{
450 struct i2c_adapter *adapter;
451 int rc;
452
453 adapter = &iface->adapter;
454
455 rc = scx200_acb_probe(iface);
456 if (rc) {
457 pr_warn("probe failed\n");
458 return rc;
459 }
460
461 scx200_acb_reset(iface);
462
463 if (i2c_add_adapter(adapter) < 0) {
464 pr_err("failed to register\n");
465 return -ENODEV;
466 }
467
468 if (!adapter->dev.parent) {
469
470 mutex_lock(&scx200_acb_list_mutex);
471 iface->next = scx200_acb_list;
472 scx200_acb_list = iface;
473 mutex_unlock(&scx200_acb_list_mutex);
474 }
475
476 return 0;
477}
478
479static struct scx200_acb_iface *scx200_create_dev(const char *text,
480 unsigned long base, int index, struct device *dev)
481{
482 struct scx200_acb_iface *iface;
483 int rc;
484
485 iface = scx200_create_iface(text, dev, index);
486
487 if (iface == NULL)
488 return NULL;
489
490 if (!request_region(base, 8, iface->adapter.name)) {
491 pr_err("can't allocate io 0x%lx-0x%lx\n", base, base + 8 - 1);
492 goto errout_free;
493 }
494
495 iface->base = base;
496 rc = scx200_acb_create(iface);
497
498 if (rc == 0)
499 return iface;
500
501 release_region(base, 8);
502 errout_free:
503 kfree(iface);
504 return NULL;
505}
506
507static int scx200_probe(struct platform_device *pdev)
508{
509 struct scx200_acb_iface *iface;
510 struct resource *res;
511
512 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
513 if (!res) {
514 dev_err(&pdev->dev, "can't fetch device resource info\n");
515 return -ENODEV;
516 }
517
518 iface = scx200_create_dev("CS5535", res->start, 0, &pdev->dev);
519 if (!iface)
520 return -EIO;
521
522 dev_info(&pdev->dev, "SCx200 device '%s' registered\n",
523 iface->adapter.name);
524 platform_set_drvdata(pdev, iface);
525
526 return 0;
527}
528
529static void scx200_cleanup_iface(struct scx200_acb_iface *iface)
530{
531 i2c_del_adapter(&iface->adapter);
532 release_region(iface->base, 8);
533 kfree(iface);
534}
535
536static int scx200_remove(struct platform_device *pdev)
537{
538 struct scx200_acb_iface *iface;
539
540 iface = platform_get_drvdata(pdev);
541 scx200_cleanup_iface(iface);
542
543 return 0;
544}
545
546static struct platform_driver scx200_pci_driver = {
547 .driver = {
548 .name = "cs5535-smb",
549 .owner = THIS_MODULE,
550 },
551 .probe = scx200_probe,
552 .remove = scx200_remove,
553};
554
555static const struct pci_device_id scx200_isa[] = {
556 { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE) },
557 { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE) },
558 { 0, }
559};
560
561static __init void scx200_scan_isa(void)
562{
563 int i;
564
565 if (!pci_dev_present(scx200_isa))
566 return;
567
568 for (i = 0; i < MAX_DEVICES; ++i) {
569 if (base[i] == 0)
570 continue;
571
572
573 scx200_create_dev("SCx200", base[i], i, NULL);
574 }
575}
576
577static int __init scx200_acb_init(void)
578{
579 pr_debug("NatSemi SCx200 ACCESS.bus Driver\n");
580
581
582 scx200_scan_isa();
583
584
585 if (scx200_acb_list)
586 return 0;
587
588
589 return platform_driver_register(&scx200_pci_driver);
590}
591
592static void __exit scx200_acb_cleanup(void)
593{
594 struct scx200_acb_iface *iface;
595
596 platform_driver_unregister(&scx200_pci_driver);
597
598 mutex_lock(&scx200_acb_list_mutex);
599 while ((iface = scx200_acb_list) != NULL) {
600 scx200_acb_list = iface->next;
601 mutex_unlock(&scx200_acb_list_mutex);
602
603 scx200_cleanup_iface(iface);
604
605 mutex_lock(&scx200_acb_list_mutex);
606 }
607 mutex_unlock(&scx200_acb_list_mutex);
608}
609
610module_init(scx200_acb_init);
611module_exit(scx200_acb_cleanup);
612
