dc64f8b6b24ab6768ed958c4737b724a450c81cd
[linux-2.6.git] / 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/pci.h>
32 #include <linux/delay.h>
33 #include <linux/mutex.h>
34 #include <asm/io.h>
35
36 #include <linux/scx200.h>
37
38 #define NAME "scx200_acb"
39
40 MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
41 MODULE_DESCRIPTION("NatSemi SCx200 ACCESS.bus Driver");
42 MODULE_LICENSE("GPL");
43
44 #define MAX_DEVICES 4
45 static int base[MAX_DEVICES] = { 0x820, 0x840 };
46 module_param_array(base, int, NULL, 0);
47 MODULE_PARM_DESC(base, "Base addresses for the ACCESS.bus controllers");
48
49 #define POLL_TIMEOUT    (HZ/5)
50
51 enum scx200_acb_state {
52         state_idle,
53         state_address,
54         state_command,
55         state_repeat_start,
56         state_quick,
57         state_read,
58         state_write,
59 };
60
61 static const char *scx200_acb_state_name[] = {
62         "idle",
63         "address",
64         "command",
65         "repeat_start",
66         "quick",
67         "read",
68         "write",
69 };
70
71 /* Physical interface */
72 struct scx200_acb_iface {
73         struct scx200_acb_iface *next;
74         struct i2c_adapter adapter;
75         unsigned base;
76         struct mutex mutex;
77
78         /* State machine data */
79         enum scx200_acb_state state;
80         int result;
81         u8 address_byte;
82         u8 command;
83         u8 *ptr;
84         char needs_reset;
85         unsigned len;
86
87         /* PCI device info */
88         struct pci_dev *pdev;
89         int bar;
90 };
91
92 /* Register Definitions */
93 #define ACBSDA          (iface->base + 0)
94 #define ACBST           (iface->base + 1)
95 #define    ACBST_SDAST          0x40 /* SDA Status */
96 #define    ACBST_BER            0x20
97 #define    ACBST_NEGACK         0x10 /* Negative Acknowledge */
98 #define    ACBST_STASTR         0x08 /* Stall After Start */
99 #define    ACBST_MASTER         0x02
100 #define ACBCST          (iface->base + 2)
101 #define    ACBCST_BB            0x02
102 #define ACBCTL1         (iface->base + 3)
103 #define    ACBCTL1_STASTRE      0x80
104 #define    ACBCTL1_NMINTE       0x40
105 #define    ACBCTL1_ACK          0x10
106 #define    ACBCTL1_STOP         0x02
107 #define    ACBCTL1_START        0x01
108 #define ACBADDR         (iface->base + 4)
109 #define ACBCTL2         (iface->base + 5)
110 #define    ACBCTL2_ENABLE       0x01
111
112 /************************************************************************/
113
114 static void scx200_acb_machine(struct scx200_acb_iface *iface, u8 status)
115 {
116         const char *errmsg;
117
118         dev_dbg(&iface->adapter.dev, "state %s, status = 0x%02x\n",
119                 scx200_acb_state_name[iface->state], status);
120
121         if (status & ACBST_BER) {
122                 errmsg = "bus error";
123                 goto error;
124         }
125         if (!(status & ACBST_MASTER)) {
126                 errmsg = "not master";
127                 goto error;
128         }
129         if (status & ACBST_NEGACK) {
130                 dev_dbg(&iface->adapter.dev, "negative ack in state %s\n",
131                         scx200_acb_state_name[iface->state]);
132
133                 iface->state = state_idle;
134                 iface->result = -ENXIO;
135
136                 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
137                 outb(ACBST_STASTR | ACBST_NEGACK, ACBST);
138
139                 /* Reset the status register */
140                 outb(0, ACBST);
141                 return;
142         }
143
144         switch (iface->state) {
145         case state_idle:
146                 dev_warn(&iface->adapter.dev, "interrupt in idle state\n");
147                 break;
148
149         case state_address:
150                 /* Do a pointer write first */
151                 outb(iface->address_byte & ~1, ACBSDA);
152
153                 iface->state = state_command;
154                 break;
155
156         case state_command:
157                 outb(iface->command, ACBSDA);
158
159                 if (iface->address_byte & 1)
160                         iface->state = state_repeat_start;
161                 else
162                         iface->state = state_write;
163                 break;
164
165         case state_repeat_start:
166                 outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
167                 /* fallthrough */
168
169         case state_quick:
170                 if (iface->address_byte & 1) {
171                         if (iface->len == 1)
172                                 outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
173                         else
174                                 outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
175                         outb(iface->address_byte, ACBSDA);
176
177                         iface->state = state_read;
178                 } else {
179                         outb(iface->address_byte, ACBSDA);
180
181                         iface->state = state_write;
182                 }
183                 break;
184
185         case state_read:
186                 /* Set ACK if _next_ byte will be the last one */
187                 if (iface->len == 2)
188                         outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
189                 else
190                         outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
191
192                 if (iface->len == 1) {
193                         iface->result = 0;
194                         iface->state = state_idle;
195                         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
196                 }
197
198                 *iface->ptr++ = inb(ACBSDA);
199                 --iface->len;
200
201                 break;
202
203         case state_write:
204                 if (iface->len == 0) {
205                         iface->result = 0;
206                         iface->state = state_idle;
207                         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
208                         break;
209                 }
210
211                 outb(*iface->ptr++, ACBSDA);
212                 --iface->len;
213
214                 break;
215         }
216
217         return;
218
219  error:
220         dev_err(&iface->adapter.dev, "%s in state %s\n", errmsg,
221                 scx200_acb_state_name[iface->state]);
222
223         iface->state = state_idle;
224         iface->result = -EIO;
225         iface->needs_reset = 1;
226 }
227
228 static void scx200_acb_poll(struct scx200_acb_iface *iface)
229 {
230         u8 status;
231         unsigned long timeout;
232
233         timeout = jiffies + POLL_TIMEOUT;
234         while (1) {
235                 status = inb(ACBST);
236
237                 /* Reset the status register to avoid the hang */
238                 outb(0, ACBST);
239
240                 if ((status & (ACBST_SDAST|ACBST_BER|ACBST_NEGACK)) != 0) {
241                         scx200_acb_machine(iface, status);
242                         return;
243                 }
244                 if (time_after(jiffies, timeout))
245                         break;
246                 cpu_relax();
247                 cond_resched();
248         }
249
250         dev_err(&iface->adapter.dev, "timeout in state %s\n",
251                 scx200_acb_state_name[iface->state]);
252
253         iface->state = state_idle;
254         iface->result = -EIO;
255         iface->needs_reset = 1;
256 }
257
258 static void scx200_acb_reset(struct scx200_acb_iface *iface)
259 {
260         /* Disable the ACCESS.bus device and Configure the SCL
261            frequency: 16 clock cycles */
262         outb(0x70, ACBCTL2);
263         /* Polling mode */
264         outb(0, ACBCTL1);
265         /* Disable slave address */
266         outb(0, ACBADDR);
267         /* Enable the ACCESS.bus device */
268         outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
269         /* Free STALL after START */
270         outb(inb(ACBCTL1) & ~(ACBCTL1_STASTRE | ACBCTL1_NMINTE), ACBCTL1);
271         /* Send a STOP */
272         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
273         /* Clear BER, NEGACK and STASTR bits */
274         outb(ACBST_BER | ACBST_NEGACK | ACBST_STASTR, ACBST);
275         /* Clear BB bit */
276         outb(inb(ACBCST) | ACBCST_BB, ACBCST);
277 }
278
279 static s32 scx200_acb_smbus_xfer(struct i2c_adapter *adapter,
280                                  u16 address, unsigned short flags,
281                                  char rw, u8 command, int size,
282                                  union i2c_smbus_data *data)
283 {
284         struct scx200_acb_iface *iface = i2c_get_adapdata(adapter);
285         int len;
286         u8 *buffer;
287         u16 cur_word;
288         int rc;
289
290         switch (size) {
291         case I2C_SMBUS_QUICK:
292                 len = 0;
293                 buffer = NULL;
294                 break;
295
296         case I2C_SMBUS_BYTE:
297                 len = 1;
298                 buffer = rw ? &data->byte : &command;
299                 break;
300
301         case I2C_SMBUS_BYTE_DATA:
302                 len = 1;
303                 buffer = &data->byte;
304                 break;
305
306         case I2C_SMBUS_WORD_DATA:
307                 len = 2;
308                 cur_word = cpu_to_le16(data->word);
309                 buffer = (u8 *)&cur_word;
310                 break;
311
312         case I2C_SMBUS_I2C_BLOCK_DATA:
313                 if (rw == I2C_SMBUS_READ)
314                         data->block[0] = I2C_SMBUS_BLOCK_MAX; /* For now */
315                 len = data->block[0];
316                 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
317                         return -EINVAL;
318                 buffer = &data->block[1];
319                 break;
320
321         default:
322                 return -EINVAL;
323         }
324
325         dev_dbg(&adapter->dev,
326                 "size=%d, address=0x%x, command=0x%x, len=%d, read=%d\n",
327                 size, address, command, len, rw);
328
329         if (!len && rw == I2C_SMBUS_READ) {
330                 dev_dbg(&adapter->dev, "zero length read\n");
331                 return -EINVAL;
332         }
333
334         mutex_lock(&iface->mutex);
335
336         iface->address_byte = (address << 1) | rw;
337         iface->command = command;
338         iface->ptr = buffer;
339         iface->len = len;
340         iface->result = -EINVAL;
341         iface->needs_reset = 0;
342
343         outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
344
345         if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE)
346                 iface->state = state_quick;
347         else
348                 iface->state = state_address;
349
350         while (iface->state != state_idle)
351                 scx200_acb_poll(iface);
352
353         if (iface->needs_reset)
354                 scx200_acb_reset(iface);
355
356         rc = iface->result;
357
358         mutex_unlock(&iface->mutex);
359
360         if (rc == 0 && size == I2C_SMBUS_WORD_DATA && rw == I2C_SMBUS_READ)
361                 data->word = le16_to_cpu(cur_word);
362
363 #ifdef DEBUG
364         dev_dbg(&adapter->dev, "transfer done, result: %d", rc);
365         if (buffer) {
366                 int i;
367                 printk(" data:");
368                 for (i = 0; i < len; ++i)
369                         printk(" %02x", buffer[i]);
370         }
371         printk("\n");
372 #endif
373
374         return rc;
375 }
376
377 static u32 scx200_acb_func(struct i2c_adapter *adapter)
378 {
379         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
380                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
381                I2C_FUNC_SMBUS_I2C_BLOCK;
382 }
383
384 /* For now, we only handle combined mode (smbus) */
385 static const struct i2c_algorithm scx200_acb_algorithm = {
386         .smbus_xfer     = scx200_acb_smbus_xfer,
387         .functionality  = scx200_acb_func,
388 };
389
390 static struct scx200_acb_iface *scx200_acb_list;
391 static DEFINE_MUTEX(scx200_acb_list_mutex);
392
393 static __init int scx200_acb_probe(struct scx200_acb_iface *iface)
394 {
395         u8 val;
396
397         /* Disable the ACCESS.bus device and Configure the SCL
398            frequency: 16 clock cycles */
399         outb(0x70, ACBCTL2);
400
401         if (inb(ACBCTL2) != 0x70) {
402                 pr_debug(NAME ": ACBCTL2 readback failed\n");
403                 return -ENXIO;
404         }
405
406         outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
407
408         val = inb(ACBCTL1);
409         if (val) {
410                 pr_debug(NAME ": disabled, but ACBCTL1=0x%02x\n",
411                         val);
412                 return -ENXIO;
413         }
414
415         outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
416
417         outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
418
419         val = inb(ACBCTL1);
420         if ((val & ACBCTL1_NMINTE) != ACBCTL1_NMINTE) {
421                 pr_debug(NAME ": enabled, but NMINTE won't be set, "
422                          "ACBCTL1=0x%02x\n", val);
423                 return -ENXIO;
424         }
425
426         return 0;
427 }
428
429 static __init struct scx200_acb_iface *scx200_create_iface(const char *text,
430                 struct device *dev, int index)
431 {
432         struct scx200_acb_iface *iface;
433         struct i2c_adapter *adapter;
434
435         iface = kzalloc(sizeof(*iface), GFP_KERNEL);
436         if (!iface) {
437                 printk(KERN_ERR NAME ": can't allocate memory\n");
438                 return NULL;
439         }
440
441         adapter = &iface->adapter;
442         i2c_set_adapdata(adapter, iface);
443         snprintf(adapter->name, sizeof(adapter->name), "%s ACB%d", text, index);
444         adapter->owner = THIS_MODULE;
445         adapter->id = I2C_HW_SMBUS_SCX200;
446         adapter->algo = &scx200_acb_algorithm;
447         adapter->class = I2C_CLASS_HWMON;
448         adapter->dev.parent = dev;
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         mutex_lock(&scx200_acb_list_mutex);
476         iface->next = scx200_acb_list;
477         scx200_acb_list = iface;
478         mutex_unlock(&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, &pdev->dev, 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, NULL, 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                         pci_dev_put(pdev);
602                         for (i = 0; i < MAX_DEVICES; ++i) {
603                                 if (base[i] == 0)
604                                         continue;
605
606                                 rc = scx200_create_isa(scx200_data[data].name,
607                                                 base[i],
608                                                 i);
609                         }
610                 }
611
612                 break;
613         }
614
615         return rc;
616 }
617
618 static int __init scx200_acb_init(void)
619 {
620         int rc;
621
622         pr_debug(NAME ": NatSemi SCx200 ACCESS.bus Driver\n");
623
624         rc = scx200_scan_pci();
625
626         /* If at least one bus was created, init must succeed */
627         if (scx200_acb_list)
628                 return 0;
629         return rc;
630 }
631
632 static void __exit scx200_acb_cleanup(void)
633 {
634         struct scx200_acb_iface *iface;
635
636         mutex_lock(&scx200_acb_list_mutex);
637         while ((iface = scx200_acb_list) != NULL) {
638                 scx200_acb_list = iface->next;
639                 mutex_unlock(&scx200_acb_list_mutex);
640
641                 i2c_del_adapter(&iface->adapter);
642
643                 if (iface->pdev) {
644                         pci_release_region(iface->pdev, iface->bar);
645                         pci_dev_put(iface->pdev);
646                 }
647                 else
648                         release_region(iface->base, 8);
649
650                 kfree(iface);
651                 mutex_lock(&scx200_acb_list_mutex);
652         }
653         mutex_unlock(&scx200_acb_list_mutex);
654 }
655
656 module_init(scx200_acb_init);
657 module_exit(scx200_acb_cleanup);