i2c: Fix the i2c_smbus_read_i2c_block_data() prototype
[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                 len = data->block[0];
314                 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
315                         return -EINVAL;
316                 buffer = &data->block[1];
317                 break;
318
319         default:
320                 return -EINVAL;
321         }
322
323         dev_dbg(&adapter->dev,
324                 "size=%d, address=0x%x, command=0x%x, len=%d, read=%d\n",
325                 size, address, command, len, rw);
326
327         if (!len && rw == I2C_SMBUS_READ) {
328                 dev_dbg(&adapter->dev, "zero length read\n");
329                 return -EINVAL;
330         }
331
332         mutex_lock(&iface->mutex);
333
334         iface->address_byte = (address << 1) | rw;
335         iface->command = command;
336         iface->ptr = buffer;
337         iface->len = len;
338         iface->result = -EINVAL;
339         iface->needs_reset = 0;
340
341         outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
342
343         if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE)
344                 iface->state = state_quick;
345         else
346                 iface->state = state_address;
347
348         while (iface->state != state_idle)
349                 scx200_acb_poll(iface);
350
351         if (iface->needs_reset)
352                 scx200_acb_reset(iface);
353
354         rc = iface->result;
355
356         mutex_unlock(&iface->mutex);
357
358         if (rc == 0 && size == I2C_SMBUS_WORD_DATA && rw == I2C_SMBUS_READ)
359                 data->word = le16_to_cpu(cur_word);
360
361 #ifdef DEBUG
362         dev_dbg(&adapter->dev, "transfer done, result: %d", rc);
363         if (buffer) {
364                 int i;
365                 printk(" data:");
366                 for (i = 0; i < len; ++i)
367                         printk(" %02x", buffer[i]);
368         }
369         printk("\n");
370 #endif
371
372         return rc;
373 }
374
375 static u32 scx200_acb_func(struct i2c_adapter *adapter)
376 {
377         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
378                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
379                I2C_FUNC_SMBUS_I2C_BLOCK;
380 }
381
382 /* For now, we only handle combined mode (smbus) */
383 static const struct i2c_algorithm scx200_acb_algorithm = {
384         .smbus_xfer     = scx200_acb_smbus_xfer,
385         .functionality  = scx200_acb_func,
386 };
387
388 static struct scx200_acb_iface *scx200_acb_list;
389 static DEFINE_MUTEX(scx200_acb_list_mutex);
390
391 static __init int scx200_acb_probe(struct scx200_acb_iface *iface)
392 {
393         u8 val;
394
395         /* Disable the ACCESS.bus device and Configure the SCL
396            frequency: 16 clock cycles */
397         outb(0x70, ACBCTL2);
398
399         if (inb(ACBCTL2) != 0x70) {
400                 pr_debug(NAME ": ACBCTL2 readback failed\n");
401                 return -ENXIO;
402         }
403
404         outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
405
406         val = inb(ACBCTL1);
407         if (val) {
408                 pr_debug(NAME ": disabled, but ACBCTL1=0x%02x\n",
409                         val);
410                 return -ENXIO;
411         }
412
413         outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
414
415         outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
416
417         val = inb(ACBCTL1);
418         if ((val & ACBCTL1_NMINTE) != ACBCTL1_NMINTE) {
419                 pr_debug(NAME ": enabled, but NMINTE won't be set, "
420                          "ACBCTL1=0x%02x\n", val);
421                 return -ENXIO;
422         }
423
424         return 0;
425 }
426
427 static __init struct scx200_acb_iface *scx200_create_iface(const char *text,
428                 struct device *dev, int index)
429 {
430         struct scx200_acb_iface *iface;
431         struct i2c_adapter *adapter;
432
433         iface = kzalloc(sizeof(*iface), GFP_KERNEL);
434         if (!iface) {
435                 printk(KERN_ERR NAME ": can't allocate memory\n");
436                 return NULL;
437         }
438
439         adapter = &iface->adapter;
440         i2c_set_adapdata(adapter, iface);
441         snprintf(adapter->name, sizeof(adapter->name), "%s ACB%d", text, index);
442         adapter->owner = THIS_MODULE;
443         adapter->id = I2C_HW_SMBUS_SCX200;
444         adapter->algo = &scx200_acb_algorithm;
445         adapter->class = I2C_CLASS_HWMON;
446         adapter->dev.parent = dev;
447
448         mutex_init(&iface->mutex);
449
450         return iface;
451 }
452
453 static int __init scx200_acb_create(struct scx200_acb_iface *iface)
454 {
455         struct i2c_adapter *adapter;
456         int rc;
457
458         adapter = &iface->adapter;
459
460         rc = scx200_acb_probe(iface);
461         if (rc) {
462                 printk(KERN_WARNING NAME ": probe failed\n");
463                 return rc;
464         }
465
466         scx200_acb_reset(iface);
467
468         if (i2c_add_adapter(adapter) < 0) {
469                 printk(KERN_ERR NAME ": failed to register\n");
470                 return -ENODEV;
471         }
472
473         mutex_lock(&scx200_acb_list_mutex);
474         iface->next = scx200_acb_list;
475         scx200_acb_list = iface;
476         mutex_unlock(&scx200_acb_list_mutex);
477
478         return 0;
479 }
480
481 static __init int scx200_create_pci(const char *text, struct pci_dev *pdev,
482                 int bar)
483 {
484         struct scx200_acb_iface *iface;
485         int rc;
486
487         iface = scx200_create_iface(text, &pdev->dev, 0);
488
489         if (iface == NULL)
490                 return -ENOMEM;
491
492         iface->pdev = pdev;
493         iface->bar = bar;
494
495         rc = pci_enable_device_bars(iface->pdev, 1 << iface->bar);
496         if (rc)
497                 goto errout_free;
498
499         rc = pci_request_region(iface->pdev, iface->bar, iface->adapter.name);
500         if (rc) {
501                 printk(KERN_ERR NAME ": can't allocate PCI BAR %d\n",
502                                 iface->bar);
503                 goto errout_free;
504         }
505
506         iface->base = pci_resource_start(iface->pdev, iface->bar);
507         rc = scx200_acb_create(iface);
508
509         if (rc == 0)
510                 return 0;
511
512         pci_release_region(iface->pdev, iface->bar);
513         pci_dev_put(iface->pdev);
514  errout_free:
515         kfree(iface);
516         return rc;
517 }
518
519 static int __init scx200_create_isa(const char *text, unsigned long base,
520                 int index)
521 {
522         struct scx200_acb_iface *iface;
523         int rc;
524
525         iface = scx200_create_iface(text, NULL, index);
526
527         if (iface == NULL)
528                 return -ENOMEM;
529
530         if (request_region(base, 8, iface->adapter.name) == 0) {
531                 printk(KERN_ERR NAME ": can't allocate io 0x%lx-0x%lx\n",
532                        base, base + 8 - 1);
533                 rc = -EBUSY;
534                 goto errout_free;
535         }
536
537         iface->base = base;
538         rc = scx200_acb_create(iface);
539
540         if (rc == 0)
541                 return 0;
542
543         release_region(base, 8);
544  errout_free:
545         kfree(iface);
546         return rc;
547 }
548
549 /* Driver data is an index into the scx200_data array that indicates
550  * the name and the BAR where the I/O address resource is located.  ISA
551  * devices are flagged with a bar value of -1 */
552
553 static struct pci_device_id scx200_pci[] = {
554         { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE),
555           .driver_data = 0 },
556         { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE),
557           .driver_data = 0 },
558         { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_CS5535_ISA),
559           .driver_data = 1 },
560         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA),
561           .driver_data = 2 }
562 };
563
564 static struct {
565         const char *name;
566         int bar;
567 } scx200_data[] = {
568         { "SCx200", -1 },
569         { "CS5535",  0 },
570         { "CS5536",  0 }
571 };
572
573 static __init int scx200_scan_pci(void)
574 {
575         int data, dev;
576         int rc = -ENODEV;
577         struct pci_dev *pdev;
578
579         for(dev = 0; dev < ARRAY_SIZE(scx200_pci); dev++) {
580                 pdev = pci_get_device(scx200_pci[dev].vendor,
581                                 scx200_pci[dev].device, NULL);
582
583                 if (pdev == NULL)
584                         continue;
585
586                 data = scx200_pci[dev].driver_data;
587
588                 /* if .bar is greater or equal to zero, this is a
589                  * PCI device - otherwise, we assume
590                    that the ports are ISA based
591                 */
592
593                 if (scx200_data[data].bar >= 0)
594                         rc = scx200_create_pci(scx200_data[data].name, pdev,
595                                         scx200_data[data].bar);
596                 else {
597                         int i;
598
599                         pci_dev_put(pdev);
600                         for (i = 0; i < MAX_DEVICES; ++i) {
601                                 if (base[i] == 0)
602                                         continue;
603
604                                 rc = scx200_create_isa(scx200_data[data].name,
605                                                 base[i],
606                                                 i);
607                         }
608                 }
609
610                 break;
611         }
612
613         return rc;
614 }
615
616 static int __init scx200_acb_init(void)
617 {
618         int rc;
619
620         pr_debug(NAME ": NatSemi SCx200 ACCESS.bus Driver\n");
621
622         rc = scx200_scan_pci();
623
624         /* If at least one bus was created, init must succeed */
625         if (scx200_acb_list)
626                 return 0;
627         return rc;
628 }
629
630 static void __exit scx200_acb_cleanup(void)
631 {
632         struct scx200_acb_iface *iface;
633
634         mutex_lock(&scx200_acb_list_mutex);
635         while ((iface = scx200_acb_list) != NULL) {
636                 scx200_acb_list = iface->next;
637                 mutex_unlock(&scx200_acb_list_mutex);
638
639                 i2c_del_adapter(&iface->adapter);
640
641                 if (iface->pdev) {
642                         pci_release_region(iface->pdev, iface->bar);
643                         pci_dev_put(iface->pdev);
644                 }
645                 else
646                         release_region(iface->base, 8);
647
648                 kfree(iface);
649                 mutex_lock(&scx200_acb_list_mutex);
650         }
651         mutex_unlock(&scx200_acb_list_mutex);
652 }
653
654 module_init(scx200_acb_init);
655 module_exit(scx200_acb_cleanup);