[PATCH] firmware_class: s/semaphores/mutexes
[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 #include <asm/msr.h>
37
38 #include <linux/scx200.h>
39
40 #define NAME "scx200_acb"
41
42 MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
43 MODULE_DESCRIPTION("NatSemi SCx200 ACCESS.bus Driver");
44 MODULE_LICENSE("GPL");
45
46 #define MAX_DEVICES 4
47 static int base[MAX_DEVICES] = { 0x820, 0x840 };
48 module_param_array(base, int, NULL, 0);
49 MODULE_PARM_DESC(base, "Base addresses for the ACCESS.bus controllers");
50
51 #define POLL_TIMEOUT    (HZ/5)
52
53 enum scx200_acb_state {
54         state_idle,
55         state_address,
56         state_command,
57         state_repeat_start,
58         state_quick,
59         state_read,
60         state_write,
61 };
62
63 static const char *scx200_acb_state_name[] = {
64         "idle",
65         "address",
66         "command",
67         "repeat_start",
68         "quick",
69         "read",
70         "write",
71 };
72
73 /* Physical interface */
74 struct scx200_acb_iface {
75         struct scx200_acb_iface *next;
76         struct i2c_adapter adapter;
77         unsigned base;
78         struct mutex mutex;
79
80         /* State machine data */
81         enum scx200_acb_state state;
82         int result;
83         u8 address_byte;
84         u8 command;
85         u8 *ptr;
86         char needs_reset;
87         unsigned len;
88 };
89
90 /* Register Definitions */
91 #define ACBSDA          (iface->base + 0)
92 #define ACBST           (iface->base + 1)
93 #define    ACBST_SDAST          0x40 /* SDA Status */
94 #define    ACBST_BER            0x20
95 #define    ACBST_NEGACK         0x10 /* Negative Acknowledge */
96 #define    ACBST_STASTR         0x08 /* Stall After Start */
97 #define    ACBST_MASTER         0x02
98 #define ACBCST          (iface->base + 2)
99 #define    ACBCST_BB            0x02
100 #define ACBCTL1         (iface->base + 3)
101 #define    ACBCTL1_STASTRE      0x80
102 #define    ACBCTL1_NMINTE       0x40
103 #define    ACBCTL1_ACK          0x10
104 #define    ACBCTL1_STOP         0x02
105 #define    ACBCTL1_START        0x01
106 #define ACBADDR         (iface->base + 4)
107 #define ACBCTL2         (iface->base + 5)
108 #define    ACBCTL2_ENABLE       0x01
109
110 /************************************************************************/
111
112 static void scx200_acb_machine(struct scx200_acb_iface *iface, u8 status)
113 {
114         const char *errmsg;
115
116         dev_dbg(&iface->adapter.dev, "state %s, status = 0x%02x\n",
117                 scx200_acb_state_name[iface->state], status);
118
119         if (status & ACBST_BER) {
120                 errmsg = "bus error";
121                 goto error;
122         }
123         if (!(status & ACBST_MASTER)) {
124                 errmsg = "not master";
125                 goto error;
126         }
127         if (status & ACBST_NEGACK) {
128                 dev_dbg(&iface->adapter.dev, "negative ack in state %s\n",
129                         scx200_acb_state_name[iface->state]);
130
131                 iface->state = state_idle;
132                 iface->result = -ENXIO;
133
134                 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
135                 outb(ACBST_STASTR | ACBST_NEGACK, ACBST);
136
137                 /* Reset the status register */
138                 outb(0, ACBST);
139                 return;
140         }
141
142         switch (iface->state) {
143         case state_idle:
144                 dev_warn(&iface->adapter.dev, "interrupt in idle state\n");
145                 break;
146
147         case state_address:
148                 /* Do a pointer write first */
149                 outb(iface->address_byte & ~1, ACBSDA);
150
151                 iface->state = state_command;
152                 break;
153
154         case state_command:
155                 outb(iface->command, ACBSDA);
156
157                 if (iface->address_byte & 1)
158                         iface->state = state_repeat_start;
159                 else
160                         iface->state = state_write;
161                 break;
162
163         case state_repeat_start:
164                 outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
165                 /* fallthrough */
166
167         case state_quick:
168                 if (iface->address_byte & 1) {
169                         if (iface->len == 1)
170                                 outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
171                         else
172                                 outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
173                         outb(iface->address_byte, ACBSDA);
174
175                         iface->state = state_read;
176                 } else {
177                         outb(iface->address_byte, ACBSDA);
178
179                         iface->state = state_write;
180                 }
181                 break;
182
183         case state_read:
184                 /* Set ACK if receiving the last byte */
185                 if (iface->len == 1)
186                         outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
187                 else
188                         outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
189
190                 *iface->ptr++ = inb(ACBSDA);
191                 --iface->len;
192
193                 if (iface->len == 0) {
194                         iface->result = 0;
195                         iface->state = state_idle;
196                         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
197                 }
198
199                 break;
200
201         case state_write:
202                 if (iface->len == 0) {
203                         iface->result = 0;
204                         iface->state = state_idle;
205                         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
206                         break;
207                 }
208
209                 outb(*iface->ptr++, ACBSDA);
210                 --iface->len;
211
212                 break;
213         }
214
215         return;
216
217  error:
218         dev_err(&iface->adapter.dev, "%s in state %s\n", errmsg,
219                 scx200_acb_state_name[iface->state]);
220
221         iface->state = state_idle;
222         iface->result = -EIO;
223         iface->needs_reset = 1;
224 }
225
226 static void scx200_acb_poll(struct scx200_acb_iface *iface)
227 {
228         u8 status;
229         unsigned long timeout;
230
231         timeout = jiffies + POLL_TIMEOUT;
232         while (time_before(jiffies, timeout)) {
233                 status = inb(ACBST);
234
235                 /* Reset the status register to avoid the hang */
236                 outb(0, ACBST);
237
238                 if ((status & (ACBST_SDAST|ACBST_BER|ACBST_NEGACK)) != 0) {
239                         scx200_acb_machine(iface, status);
240                         return;
241                 }
242                 yield();
243         }
244
245         dev_err(&iface->adapter.dev, "timeout in state %s\n",
246                 scx200_acb_state_name[iface->state]);
247
248         iface->state = state_idle;
249         iface->result = -EIO;
250         iface->needs_reset = 1;
251 }
252
253 static void scx200_acb_reset(struct scx200_acb_iface *iface)
254 {
255         /* Disable the ACCESS.bus device and Configure the SCL
256            frequency: 16 clock cycles */
257         outb(0x70, ACBCTL2);
258         /* Polling mode */
259         outb(0, ACBCTL1);
260         /* Disable slave address */
261         outb(0, ACBADDR);
262         /* Enable the ACCESS.bus device */
263         outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
264         /* Free STALL after START */
265         outb(inb(ACBCTL1) & ~(ACBCTL1_STASTRE | ACBCTL1_NMINTE), ACBCTL1);
266         /* Send a STOP */
267         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
268         /* Clear BER, NEGACK and STASTR bits */
269         outb(ACBST_BER | ACBST_NEGACK | ACBST_STASTR, ACBST);
270         /* Clear BB bit */
271         outb(inb(ACBCST) | ACBCST_BB, ACBCST);
272 }
273
274 static s32 scx200_acb_smbus_xfer(struct i2c_adapter *adapter,
275                                  u16 address, unsigned short flags,
276                                  char rw, u8 command, int size,
277                                  union i2c_smbus_data *data)
278 {
279         struct scx200_acb_iface *iface = i2c_get_adapdata(adapter);
280         int len;
281         u8 *buffer;
282         u16 cur_word;
283         int rc;
284
285         switch (size) {
286         case I2C_SMBUS_QUICK:
287                 len = 0;
288                 buffer = NULL;
289                 break;
290
291         case I2C_SMBUS_BYTE:
292                 len = 1;
293                 buffer = rw ? &data->byte : &command;
294                 break;
295
296         case I2C_SMBUS_BYTE_DATA:
297                 len = 1;
298                 buffer = &data->byte;
299                 break;
300
301         case I2C_SMBUS_WORD_DATA:
302                 len = 2;
303                 cur_word = cpu_to_le16(data->word);
304                 buffer = (u8 *)&cur_word;
305                 break;
306
307         case I2C_SMBUS_BLOCK_DATA:
308                 len = data->block[0];
309                 buffer = &data->block[1];
310                 break;
311
312         default:
313                 return -EINVAL;
314         }
315
316         dev_dbg(&adapter->dev,
317                 "size=%d, address=0x%x, command=0x%x, len=%d, read=%d\n",
318                 size, address, command, len, rw);
319
320         if (!len && rw == I2C_SMBUS_READ) {
321                 dev_dbg(&adapter->dev, "zero length read\n");
322                 return -EINVAL;
323         }
324
325         mutex_lock(&iface->mutex);
326
327         iface->address_byte = (address << 1) | rw;
328         iface->command = command;
329         iface->ptr = buffer;
330         iface->len = len;
331         iface->result = -EINVAL;
332         iface->needs_reset = 0;
333
334         outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
335
336         if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE)
337                 iface->state = state_quick;
338         else
339                 iface->state = state_address;
340
341         while (iface->state != state_idle)
342                 scx200_acb_poll(iface);
343
344         if (iface->needs_reset)
345                 scx200_acb_reset(iface);
346
347         rc = iface->result;
348
349         mutex_unlock(&iface->mutex);
350
351         if (rc == 0 && size == I2C_SMBUS_WORD_DATA && rw == I2C_SMBUS_READ)
352                 data->word = le16_to_cpu(cur_word);
353
354 #ifdef DEBUG
355         dev_dbg(&adapter->dev, "transfer done, result: %d", rc);
356         if (buffer) {
357                 int i;
358                 printk(" data:");
359                 for (i = 0; i < len; ++i)
360                         printk(" %02x", buffer[i]);
361         }
362         printk("\n");
363 #endif
364
365         return rc;
366 }
367
368 static u32 scx200_acb_func(struct i2c_adapter *adapter)
369 {
370         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
371                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
372                I2C_FUNC_SMBUS_BLOCK_DATA;
373 }
374
375 /* For now, we only handle combined mode (smbus) */
376 static struct i2c_algorithm scx200_acb_algorithm = {
377         .smbus_xfer     = scx200_acb_smbus_xfer,
378         .functionality  = scx200_acb_func,
379 };
380
381 static struct scx200_acb_iface *scx200_acb_list;
382 static DECLARE_MUTEX(scx200_acb_list_mutex);
383
384 static int scx200_acb_probe(struct scx200_acb_iface *iface)
385 {
386         u8 val;
387
388         /* Disable the ACCESS.bus device and Configure the SCL
389            frequency: 16 clock cycles */
390         outb(0x70, ACBCTL2);
391
392         if (inb(ACBCTL2) != 0x70) {
393                 pr_debug(NAME ": ACBCTL2 readback failed\n");
394                 return -ENXIO;
395         }
396
397         outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
398
399         val = inb(ACBCTL1);
400         if (val) {
401                 pr_debug(NAME ": disabled, but ACBCTL1=0x%02x\n",
402                         val);
403                 return -ENXIO;
404         }
405
406         outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
407
408         outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
409
410         val = inb(ACBCTL1);
411         if ((val & ACBCTL1_NMINTE) != ACBCTL1_NMINTE) {
412                 pr_debug(NAME ": enabled, but NMINTE won't be set, "
413                          "ACBCTL1=0x%02x\n", val);
414                 return -ENXIO;
415         }
416
417         return 0;
418 }
419
420 static int  __init scx200_acb_create(const char *text, int base, int index)
421 {
422         struct scx200_acb_iface *iface;
423         struct i2c_adapter *adapter;
424         int rc;
425
426         iface = kzalloc(sizeof(*iface), GFP_KERNEL);
427         if (!iface) {
428                 printk(KERN_ERR NAME ": can't allocate memory\n");
429                 rc = -ENOMEM;
430                 goto errout;
431         }
432
433         adapter = &iface->adapter;
434         i2c_set_adapdata(adapter, iface);
435         snprintf(adapter->name, I2C_NAME_SIZE, "%s ACB%d", text, index);
436         adapter->owner = THIS_MODULE;
437         adapter->id = I2C_HW_SMBUS_SCX200;
438         adapter->algo = &scx200_acb_algorithm;
439         adapter->class = I2C_CLASS_HWMON;
440
441         mutex_init(&iface->mutex);
442
443         if (!request_region(base, 8, adapter->name)) {
444                 printk(KERN_ERR NAME ": can't allocate io 0x%x-0x%x\n",
445                         base, base + 8-1);
446                 rc = -EBUSY;
447                 goto errout_free;
448         }
449         iface->base = base;
450
451         rc = scx200_acb_probe(iface);
452         if (rc) {
453                 printk(KERN_WARNING NAME ": probe failed\n");
454                 goto errout_release;
455         }
456
457         scx200_acb_reset(iface);
458
459         if (i2c_add_adapter(adapter) < 0) {
460                 printk(KERN_ERR NAME ": failed to register\n");
461                 rc = -ENODEV;
462                 goto errout_release;
463         }
464
465         down(&scx200_acb_list_mutex);
466         iface->next = scx200_acb_list;
467         scx200_acb_list = iface;
468         up(&scx200_acb_list_mutex);
469
470         return 0;
471
472  errout_release:
473         release_region(iface->base, 8);
474  errout_free:
475         kfree(iface);
476  errout:
477         return rc;
478 }
479
480 static struct pci_device_id scx200[] = {
481         { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE) },
482         { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE) },
483         { },
484 };
485
486 static struct pci_device_id divil_pci[] = {
487         { PCI_DEVICE(PCI_VENDOR_ID_NS,  PCI_DEVICE_ID_NS_CS5535_ISA) },
488         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA) },
489         { } /* NULL entry */
490 };
491
492 #define MSR_LBAR_SMB            0x5140000B
493
494 static __init int scx200_add_cs553x(void)
495 {
496         u32     low, hi;
497         u32     smb_base;
498
499         /* Grab & reserve the SMB I/O range */
500         rdmsr(MSR_LBAR_SMB, low, hi);
501
502         /* Check the IO mask and whether SMB is enabled */
503         if (hi != 0x0000F001) {
504                 printk(KERN_WARNING NAME ": SMBus not enabled\n");
505                 return -ENODEV;
506         }
507
508         /* SMBus IO size is 8 bytes */
509         smb_base = low & 0x0000FFF8;
510
511         return scx200_acb_create("CS5535", smb_base, 0);
512 }
513
514 static int __init scx200_acb_init(void)
515 {
516         int i;
517         int     rc = -ENODEV;
518
519         pr_debug(NAME ": NatSemi SCx200 ACCESS.bus Driver\n");
520
521         /* Verify that this really is a SCx200 processor */
522         if (pci_dev_present(scx200)) {
523                 for (i = 0; i < MAX_DEVICES; ++i) {
524                         if (base[i] > 0)
525                                 rc = scx200_acb_create("SCx200", base[i], i);
526                 }
527         } else if (pci_dev_present(divil_pci))
528                 rc = scx200_add_cs553x();
529
530         /* If at least one bus was created, init must succeed */
531         if (scx200_acb_list)
532                 return 0;
533         return rc;
534 }
535
536 static void __exit scx200_acb_cleanup(void)
537 {
538         struct scx200_acb_iface *iface;
539
540         down(&scx200_acb_list_mutex);
541         while ((iface = scx200_acb_list) != NULL) {
542                 scx200_acb_list = iface->next;
543                 up(&scx200_acb_list_mutex);
544
545                 i2c_del_adapter(&iface->adapter);
546                 release_region(iface->base, 8);
547                 kfree(iface);
548                 down(&scx200_acb_list_mutex);
549         }
550         up(&scx200_acb_list_mutex);
551 }
552
553 module_init(scx200_acb_init);
554 module_exit(scx200_acb_cleanup);