i2c-i801: SMBus patch for Intel ICH9
[linux-2.6] / drivers / i2c / busses / scx200_acb.c
1 /*
2     Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
3
4     National Semiconductor SCx200 ACCESS.bus support
5     Also supports the AMD CS5535 and AMD CS5536
6
7     Based on i2c-keywest.c which is:
8         Copyright (c) 2001 Benjamin Herrenschmidt <benh@kernel.crashing.org>
9         Copyright (c) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
10
11     This program is free software; you can redistribute it and/or
12     modify it under the terms of the GNU General Public License as
13     published by the Free Software Foundation; either version 2 of the
14     License, or (at your option) any later version.
15
16     This program is distributed in the hope that it will be useful,
17     but WITHOUT ANY WARRANTY; without even the implied warranty of
18     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19     General Public License for more details.
20
21     You should have received a copy of the GNU General Public License
22     along with this program; if not, write to the Free Software
23     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 */
25
26 #include <linux/module.h>
27 #include <linux/errno.h>
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/i2c.h>
31 #include <linux/smp_lock.h>
32 #include <linux/pci.h>
33 #include <linux/delay.h>
34 #include <linux/mutex.h>
35 #include <asm/io.h>
36
37 #include <linux/scx200.h>
38
39 #define NAME "scx200_acb"
40
41 MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
42 MODULE_DESCRIPTION("NatSemi SCx200 ACCESS.bus Driver");
43 MODULE_LICENSE("GPL");
44
45 #define MAX_DEVICES 4
46 static int base[MAX_DEVICES] = { 0x820, 0x840 };
47 module_param_array(base, int, NULL, 0);
48 MODULE_PARM_DESC(base, "Base addresses for the ACCESS.bus controllers");
49
50 #define POLL_TIMEOUT    (HZ/5)
51
52 enum scx200_acb_state {
53         state_idle,
54         state_address,
55         state_command,
56         state_repeat_start,
57         state_quick,
58         state_read,
59         state_write,
60 };
61
62 static const char *scx200_acb_state_name[] = {
63         "idle",
64         "address",
65         "command",
66         "repeat_start",
67         "quick",
68         "read",
69         "write",
70 };
71
72 /* Physical interface */
73 struct scx200_acb_iface {
74         struct scx200_acb_iface *next;
75         struct i2c_adapter adapter;
76         unsigned base;
77         struct mutex mutex;
78
79         /* State machine data */
80         enum scx200_acb_state state;
81         int result;
82         u8 address_byte;
83         u8 command;
84         u8 *ptr;
85         char needs_reset;
86         unsigned len;
87
88         /* PCI device info */
89         struct pci_dev *pdev;
90         int bar;
91 };
92
93 /* Register Definitions */
94 #define ACBSDA          (iface->base + 0)
95 #define ACBST           (iface->base + 1)
96 #define    ACBST_SDAST          0x40 /* SDA Status */
97 #define    ACBST_BER            0x20
98 #define    ACBST_NEGACK         0x10 /* Negative Acknowledge */
99 #define    ACBST_STASTR         0x08 /* Stall After Start */
100 #define    ACBST_MASTER         0x02
101 #define ACBCST          (iface->base + 2)
102 #define    ACBCST_BB            0x02
103 #define ACBCTL1         (iface->base + 3)
104 #define    ACBCTL1_STASTRE      0x80
105 #define    ACBCTL1_NMINTE       0x40
106 #define    ACBCTL1_ACK          0x10
107 #define    ACBCTL1_STOP         0x02
108 #define    ACBCTL1_START        0x01
109 #define ACBADDR         (iface->base + 4)
110 #define ACBCTL2         (iface->base + 5)
111 #define    ACBCTL2_ENABLE       0x01
112
113 /************************************************************************/
114
115 static void scx200_acb_machine(struct scx200_acb_iface *iface, u8 status)
116 {
117         const char *errmsg;
118
119         dev_dbg(&iface->adapter.dev, "state %s, status = 0x%02x\n",
120                 scx200_acb_state_name[iface->state], status);
121
122         if (status & ACBST_BER) {
123                 errmsg = "bus error";
124                 goto error;
125         }
126         if (!(status & ACBST_MASTER)) {
127                 errmsg = "not master";
128                 goto error;
129         }
130         if (status & ACBST_NEGACK) {
131                 dev_dbg(&iface->adapter.dev, "negative ack in state %s\n",
132                         scx200_acb_state_name[iface->state]);
133
134                 iface->state = state_idle;
135                 iface->result = -ENXIO;
136
137                 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
138                 outb(ACBST_STASTR | ACBST_NEGACK, ACBST);
139
140                 /* Reset the status register */
141                 outb(0, ACBST);
142                 return;
143         }
144
145         switch (iface->state) {
146         case state_idle:
147                 dev_warn(&iface->adapter.dev, "interrupt in idle state\n");
148                 break;
149
150         case state_address:
151                 /* Do a pointer write first */
152                 outb(iface->address_byte & ~1, ACBSDA);
153
154                 iface->state = state_command;
155                 break;
156
157         case state_command:
158                 outb(iface->command, ACBSDA);
159
160                 if (iface->address_byte & 1)
161                         iface->state = state_repeat_start;
162                 else
163                         iface->state = state_write;
164                 break;
165
166         case state_repeat_start:
167                 outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
168                 /* fallthrough */
169
170         case state_quick:
171                 if (iface->address_byte & 1) {
172                         if (iface->len == 1)
173                                 outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
174                         else
175                                 outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
176                         outb(iface->address_byte, ACBSDA);
177
178                         iface->state = state_read;
179                 } else {
180                         outb(iface->address_byte, ACBSDA);
181
182                         iface->state = state_write;
183                 }
184                 break;
185
186         case state_read:
187                 /* Set ACK if _next_ byte will be the last one */
188                 if (iface->len == 2)
189                         outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
190                 else
191                         outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
192
193                 if (iface->len == 1) {
194                         iface->result = 0;
195                         iface->state = state_idle;
196                         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
197                 }
198
199                 *iface->ptr++ = inb(ACBSDA);
200                 --iface->len;
201
202                 break;
203
204         case state_write:
205                 if (iface->len == 0) {
206                         iface->result = 0;
207                         iface->state = state_idle;
208                         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
209                         break;
210                 }
211
212                 outb(*iface->ptr++, ACBSDA);
213                 --iface->len;
214
215                 break;
216         }
217
218         return;
219
220  error:
221         dev_err(&iface->adapter.dev, "%s in state %s\n", errmsg,
222                 scx200_acb_state_name[iface->state]);
223
224         iface->state = state_idle;
225         iface->result = -EIO;
226         iface->needs_reset = 1;
227 }
228
229 static void scx200_acb_poll(struct scx200_acb_iface *iface)
230 {
231         u8 status;
232         unsigned long timeout;
233
234         timeout = jiffies + POLL_TIMEOUT;
235         while (1) {
236                 status = inb(ACBST);
237
238                 /* Reset the status register to avoid the hang */
239                 outb(0, ACBST);
240
241                 if ((status & (ACBST_SDAST|ACBST_BER|ACBST_NEGACK)) != 0) {
242                         scx200_acb_machine(iface, status);
243                         return;
244                 }
245                 if (time_after(jiffies, timeout))
246                         break;
247                 cpu_relax();
248                 cond_resched();
249         }
250
251         dev_err(&iface->adapter.dev, "timeout in state %s\n",
252                 scx200_acb_state_name[iface->state]);
253
254         iface->state = state_idle;
255         iface->result = -EIO;
256         iface->needs_reset = 1;
257 }
258
259 static void scx200_acb_reset(struct scx200_acb_iface *iface)
260 {
261         /* Disable the ACCESS.bus device and Configure the SCL
262            frequency: 16 clock cycles */
263         outb(0x70, ACBCTL2);
264         /* Polling mode */
265         outb(0, ACBCTL1);
266         /* Disable slave address */
267         outb(0, ACBADDR);
268         /* Enable the ACCESS.bus device */
269         outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
270         /* Free STALL after START */
271         outb(inb(ACBCTL1) & ~(ACBCTL1_STASTRE | ACBCTL1_NMINTE), ACBCTL1);
272         /* Send a STOP */
273         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
274         /* Clear BER, NEGACK and STASTR bits */
275         outb(ACBST_BER | ACBST_NEGACK | ACBST_STASTR, ACBST);
276         /* Clear BB bit */
277         outb(inb(ACBCST) | ACBCST_BB, ACBCST);
278 }
279
280 static s32 scx200_acb_smbus_xfer(struct i2c_adapter *adapter,
281                                  u16 address, unsigned short flags,
282                                  char rw, u8 command, int size,
283                                  union i2c_smbus_data *data)
284 {
285         struct scx200_acb_iface *iface = i2c_get_adapdata(adapter);
286         int len;
287         u8 *buffer;
288         u16 cur_word;
289         int rc;
290
291         switch (size) {
292         case I2C_SMBUS_QUICK:
293                 len = 0;
294                 buffer = NULL;
295                 break;
296
297         case I2C_SMBUS_BYTE:
298                 len = 1;
299                 buffer = rw ? &data->byte : &command;
300                 break;
301
302         case I2C_SMBUS_BYTE_DATA:
303                 len = 1;
304                 buffer = &data->byte;
305                 break;
306
307         case I2C_SMBUS_WORD_DATA:
308                 len = 2;
309                 cur_word = cpu_to_le16(data->word);
310                 buffer = (u8 *)&cur_word;
311                 break;
312
313         case I2C_SMBUS_I2C_BLOCK_DATA:
314                 if (rw == I2C_SMBUS_READ)
315                         data->block[0] = I2C_SMBUS_BLOCK_MAX; /* For now */
316                 len = data->block[0];
317                 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
318                         return -EINVAL;
319                 buffer = &data->block[1];
320                 break;
321
322         default:
323                 return -EINVAL;
324         }
325
326         dev_dbg(&adapter->dev,
327                 "size=%d, address=0x%x, command=0x%x, len=%d, read=%d\n",
328                 size, address, command, len, rw);
329
330         if (!len && rw == I2C_SMBUS_READ) {
331                 dev_dbg(&adapter->dev, "zero length read\n");
332                 return -EINVAL;
333         }
334
335         mutex_lock(&iface->mutex);
336
337         iface->address_byte = (address << 1) | rw;
338         iface->command = command;
339         iface->ptr = buffer;
340         iface->len = len;
341         iface->result = -EINVAL;
342         iface->needs_reset = 0;
343
344         outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
345
346         if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE)
347                 iface->state = state_quick;
348         else
349                 iface->state = state_address;
350
351         while (iface->state != state_idle)
352                 scx200_acb_poll(iface);
353
354         if (iface->needs_reset)
355                 scx200_acb_reset(iface);
356
357         rc = iface->result;
358
359         mutex_unlock(&iface->mutex);
360
361         if (rc == 0 && size == I2C_SMBUS_WORD_DATA && rw == I2C_SMBUS_READ)
362                 data->word = le16_to_cpu(cur_word);
363
364 #ifdef DEBUG
365         dev_dbg(&adapter->dev, "transfer done, result: %d", rc);
366         if (buffer) {
367                 int i;
368                 printk(" data:");
369                 for (i = 0; i < len; ++i)
370                         printk(" %02x", buffer[i]);
371         }
372         printk("\n");
373 #endif
374
375         return rc;
376 }
377
378 static u32 scx200_acb_func(struct i2c_adapter *adapter)
379 {
380         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
381                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
382                I2C_FUNC_SMBUS_I2C_BLOCK;
383 }
384
385 /* For now, we only handle combined mode (smbus) */
386 static const struct i2c_algorithm scx200_acb_algorithm = {
387         .smbus_xfer     = scx200_acb_smbus_xfer,
388         .functionality  = scx200_acb_func,
389 };
390
391 static struct scx200_acb_iface *scx200_acb_list;
392 static DECLARE_MUTEX(scx200_acb_list_mutex);
393
394 static __init int scx200_acb_probe(struct scx200_acb_iface *iface)
395 {
396         u8 val;
397
398         /* Disable the ACCESS.bus device and Configure the SCL
399            frequency: 16 clock cycles */
400         outb(0x70, ACBCTL2);
401
402         if (inb(ACBCTL2) != 0x70) {
403                 pr_debug(NAME ": ACBCTL2 readback failed\n");
404                 return -ENXIO;
405         }
406
407         outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
408
409         val = inb(ACBCTL1);
410         if (val) {
411                 pr_debug(NAME ": disabled, but ACBCTL1=0x%02x\n",
412                         val);
413                 return -ENXIO;
414         }
415
416         outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
417
418         outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
419
420         val = inb(ACBCTL1);
421         if ((val & ACBCTL1_NMINTE) != ACBCTL1_NMINTE) {
422                 pr_debug(NAME ": enabled, but NMINTE won't be set, "
423                          "ACBCTL1=0x%02x\n", val);
424                 return -ENXIO;
425         }
426
427         return 0;
428 }
429
430 static __init struct scx200_acb_iface *scx200_create_iface(const char *text,
431                 int index)
432 {
433         struct scx200_acb_iface *iface;
434         struct i2c_adapter *adapter;
435
436         iface = kzalloc(sizeof(*iface), GFP_KERNEL);
437         if (!iface) {
438                 printk(KERN_ERR NAME ": can't allocate memory\n");
439                 return NULL;
440         }
441
442         adapter = &iface->adapter;
443         i2c_set_adapdata(adapter, iface);
444         snprintf(adapter->name, I2C_NAME_SIZE, "%s ACB%d", text, index);
445         adapter->owner = THIS_MODULE;
446         adapter->id = I2C_HW_SMBUS_SCX200;
447         adapter->algo = &scx200_acb_algorithm;
448         adapter->class = I2C_CLASS_HWMON;
449
450         mutex_init(&iface->mutex);
451
452         return iface;
453 }
454
455 static int __init scx200_acb_create(struct scx200_acb_iface *iface)
456 {
457         struct i2c_adapter *adapter;
458         int rc;
459
460         adapter = &iface->adapter;
461
462         rc = scx200_acb_probe(iface);
463         if (rc) {
464                 printk(KERN_WARNING NAME ": probe failed\n");
465                 return rc;
466         }
467
468         scx200_acb_reset(iface);
469
470         if (i2c_add_adapter(adapter) < 0) {
471                 printk(KERN_ERR NAME ": failed to register\n");
472                 return -ENODEV;
473         }
474
475         down(&scx200_acb_list_mutex);
476         iface->next = scx200_acb_list;
477         scx200_acb_list = iface;
478         up(&scx200_acb_list_mutex);
479
480         return 0;
481 }
482
483 static __init int scx200_create_pci(const char *text, struct pci_dev *pdev,
484                 int bar)
485 {
486         struct scx200_acb_iface *iface;
487         int rc;
488
489         iface = scx200_create_iface(text, 0);
490
491         if (iface == NULL)
492                 return -ENOMEM;
493
494         iface->pdev = pdev;
495         iface->bar = bar;
496
497         rc = pci_enable_device_bars(iface->pdev, 1 << iface->bar);
498         if (rc)
499                 goto errout_free;
500
501         rc = pci_request_region(iface->pdev, iface->bar, iface->adapter.name);
502         if (rc) {
503                 printk(KERN_ERR NAME ": can't allocate PCI BAR %d\n",
504                                 iface->bar);
505                 goto errout_free;
506         }
507
508         iface->base = pci_resource_start(iface->pdev, iface->bar);
509         rc = scx200_acb_create(iface);
510
511         if (rc == 0)
512                 return 0;
513
514         pci_release_region(iface->pdev, iface->bar);
515         pci_dev_put(iface->pdev);
516  errout_free:
517         kfree(iface);
518         return rc;
519 }
520
521 static int __init scx200_create_isa(const char *text, unsigned long base,
522                 int index)
523 {
524         struct scx200_acb_iface *iface;
525         int rc;
526
527         iface = scx200_create_iface(text, index);
528
529         if (iface == NULL)
530                 return -ENOMEM;
531
532         if (request_region(base, 8, iface->adapter.name) == 0) {
533                 printk(KERN_ERR NAME ": can't allocate io 0x%lx-0x%lx\n",
534                        base, base + 8 - 1);
535                 rc = -EBUSY;
536                 goto errout_free;
537         }
538
539         iface->base = base;
540         rc = scx200_acb_create(iface);
541
542         if (rc == 0)
543                 return 0;
544
545         release_region(base, 8);
546  errout_free:
547         kfree(iface);
548         return rc;
549 }
550
551 /* Driver data is an index into the scx200_data array that indicates
552  * the name and the BAR where the I/O address resource is located.  ISA
553  * devices are flagged with a bar value of -1 */
554
555 static struct pci_device_id scx200_pci[] = {
556         { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE),
557           .driver_data = 0 },
558         { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE),
559           .driver_data = 0 },
560         { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_CS5535_ISA),
561           .driver_data = 1 },
562         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA),
563           .driver_data = 2 }
564 };
565
566 static struct {
567         const char *name;
568         int bar;
569 } scx200_data[] = {
570         { "SCx200", -1 },
571         { "CS5535",  0 },
572         { "CS5536",  0 }
573 };
574
575 static __init int scx200_scan_pci(void)
576 {
577         int data, dev;
578         int rc = -ENODEV;
579         struct pci_dev *pdev;
580
581         for(dev = 0; dev < ARRAY_SIZE(scx200_pci); dev++) {
582                 pdev = pci_get_device(scx200_pci[dev].vendor,
583                                 scx200_pci[dev].device, NULL);
584
585                 if (pdev == NULL)
586                         continue;
587
588                 data = scx200_pci[dev].driver_data;
589
590                 /* if .bar is greater or equal to zero, this is a
591                  * PCI device - otherwise, we assume
592                    that the ports are ISA based
593                 */
594
595                 if (scx200_data[data].bar >= 0)
596                         rc = scx200_create_pci(scx200_data[data].name, pdev,
597                                         scx200_data[data].bar);
598                 else {
599                         int i;
600
601                         for (i = 0; i < MAX_DEVICES; ++i) {
602                                 if (base[i] == 0)
603                                         continue;
604
605                                 rc = scx200_create_isa(scx200_data[data].name,
606                                                 base[i],
607                                                 i);
608                         }
609                 }
610
611                 break;
612         }
613
614         return rc;
615 }
616
617 static int __init scx200_acb_init(void)
618 {
619         int rc;
620
621         pr_debug(NAME ": NatSemi SCx200 ACCESS.bus Driver\n");
622
623         rc = scx200_scan_pci();
624
625         /* If at least one bus was created, init must succeed */
626         if (scx200_acb_list)
627                 return 0;
628         return rc;
629 }
630
631 static void __exit scx200_acb_cleanup(void)
632 {
633         struct scx200_acb_iface *iface;
634
635         down(&scx200_acb_list_mutex);
636         while ((iface = scx200_acb_list) != NULL) {
637                 scx200_acb_list = iface->next;
638                 up(&scx200_acb_list_mutex);
639
640                 i2c_del_adapter(&iface->adapter);
641
642                 if (iface->pdev) {
643                         pci_release_region(iface->pdev, iface->bar);
644                         pci_dev_put(iface->pdev);
645                 }
646                 else
647                         release_region(iface->base, 8);
648
649                 kfree(iface);
650                 down(&scx200_acb_list_mutex);
651         }
652         up(&scx200_acb_list_mutex);
653 }
654
655 module_init(scx200_acb_init);
656 module_exit(scx200_acb_cleanup);