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ping reqs
[cor_2_6_31.git] / drivers / i2c / busses / i2c-ali1535.c
blobd108450df064552b56f5886200231f3e53e8c57b
1 /*
2 Copyright (c) 2000 Frodo Looijaard <frodol@dds.nl>,
3 Philip Edelbrock <phil@netroedge.com>,
4 Mark D. Studebaker <mdsxyz123@yahoo.com>,
5 Dan Eaton <dan.eaton@rocketlogix.com> and
6 Stephen Rousset<stephen.rousset@rocketlogix.com>
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 */
22
23 /*
24 This is the driver for the SMB Host controller on
25 Acer Labs Inc. (ALI) M1535 South Bridge.
26
27 The M1535 is a South bridge for portable systems.
28 It is very similar to the M15x3 South bridges also produced
29 by Acer Labs Inc. Some of the registers within the part
30 have moved and some have been redefined slightly. Additionally,
31 the sequencing of the SMBus transactions has been modified
32 to be more consistent with the sequencing recommended by
33 the manufacturer and observed through testing. These
34 changes are reflected in this driver and can be identified
35 by comparing this driver to the i2c-ali15x3 driver.
36 For an overview of these chips see http://www.acerlabs.com
37
38 The SMB controller is part of the 7101 device, which is an
39 ACPI-compliant Power Management Unit (PMU).
40
41 The whole 7101 device has to be enabled for the SMB to work.
42 You can't just enable the SMB alone.
43 The SMB and the ACPI have separate I/O spaces.
44 We make sure that the SMB is enabled. We leave the ACPI alone.
45
46 This driver controls the SMB Host only.
47
48 This driver does not use interrupts.
49 */
50
51
52 /* Note: we assume there can only be one ALI1535, with one SMBus interface */
53
54 #include <linux/module.h>
55 #include <linux/pci.h>
56 #include <linux/kernel.h>
57 #include <linux/stddef.h>
58 #include <linux/delay.h>
59 #include <linux/ioport.h>
60 #include <linux/i2c.h>
61 #include <linux/init.h>
62 #include <linux/acpi.h>
63 #include <asm/io.h>
64
65
66 /* ALI1535 SMBus address offsets */
67 #define SMBHSTSTS (0 + ali1535_smba)
68 #define SMBHSTTYP (1 + ali1535_smba)
69 #define SMBHSTPORT (2 + ali1535_smba)
70 #define SMBHSTCMD (7 + ali1535_smba)
71 #define SMBHSTADD (3 + ali1535_smba)
72 #define SMBHSTDAT0 (4 + ali1535_smba)
73 #define SMBHSTDAT1 (5 + ali1535_smba)
74 #define SMBBLKDAT (6 + ali1535_smba)
75
76 /* PCI Address Constants */
77 #define SMBCOM 0x004
78 #define SMBREV 0x008
79 #define SMBCFG 0x0D1
80 #define SMBBA 0x0E2
81 #define SMBHSTCFG 0x0F0
82 #define SMBCLK 0x0F2
83
84 /* Other settings */
85 #define MAX_TIMEOUT 500 /* times 1/100 sec */
86 #define ALI1535_SMB_IOSIZE 32
87
88 #define ALI1535_SMB_DEFAULTBASE 0x8040
89
90 /* ALI1535 address lock bits */
91 #define ALI1535_LOCK 0x06 /* dwe */
92
93 /* ALI1535 command constants */
94 #define ALI1535_QUICK 0x00
95 #define ALI1535_BYTE 0x10
96 #define ALI1535_BYTE_DATA 0x20
97 #define ALI1535_WORD_DATA 0x30
98 #define ALI1535_BLOCK_DATA 0x40
99 #define ALI1535_I2C_READ 0x60
100
101 #define ALI1535_DEV10B_EN 0x80 /* Enable 10-bit addressing in */
102 /* I2C read */
103 #define ALI1535_T_OUT 0x08 /* Time-out Command (write) */
104 #define ALI1535_A_HIGH_BIT9 0x08 /* Bit 9 of 10-bit address in */
105 /* Alert-Response-Address */
106 /* (read) */
107 #define ALI1535_KILL 0x04 /* Kill Command (write) */
108 #define ALI1535_A_HIGH_BIT8 0x04 /* Bit 8 of 10-bit address in */
109 /* Alert-Response-Address */
110 /* (read) */
111
112 #define ALI1535_D_HI_MASK 0x03 /* Mask for isolating bits 9-8 */
113 /* of 10-bit address in I2C */
114 /* Read Command */
115
116 /* ALI1535 status register bits */
117 #define ALI1535_STS_IDLE 0x04
118 #define ALI1535_STS_BUSY 0x08 /* host busy */
119 #define ALI1535_STS_DONE 0x10 /* transaction complete */
120 #define ALI1535_STS_DEV 0x20 /* device error */
121 #define ALI1535_STS_BUSERR 0x40 /* bus error */
122 #define ALI1535_STS_FAIL 0x80 /* failed bus transaction */
123 #define ALI1535_STS_ERR 0xE0 /* all the bad error bits */
124
125 #define ALI1535_BLOCK_CLR 0x04 /* reset block data index */
126
127 /* ALI1535 device address register bits */
128 #define ALI1535_RD_ADDR 0x01 /* Read/Write Bit in Device */
129 /* Address field */
130 /* -> Write = 0 */
131 /* -> Read = 1 */
132 #define ALI1535_SMBIO_EN 0x04 /* SMB I/O Space enable */
133
134 static struct pci_driver ali1535_driver;
135 static unsigned short ali1535_smba;
136
137 /* Detect whether a ALI1535 can be found, and initialize it, where necessary.
138 Note the differences between kernels with the old PCI BIOS interface and
139 newer kernels with the real PCI interface. In compat.h some things are
140 defined to make the transition easier. */
141 static int ali1535_setup(struct pci_dev *dev)
142 {
143 int retval = -ENODEV;
144 unsigned char temp;
145
146 /* Check the following things:
147 - SMB I/O address is initialized
148 - Device is enabled
149 - We can use the addresses
150 */
151
152 /* Determine the address of the SMBus area */
153 pci_read_config_word(dev, SMBBA, &ali1535_smba);
154 ali1535_smba &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
155 if (ali1535_smba == 0) {
156 dev_warn(&dev->dev,
157 "ALI1535_smb region uninitialized - upgrade BIOS?\n");
158 goto exit;
159 }
160
161 retval = acpi_check_region(ali1535_smba, ALI1535_SMB_IOSIZE,
162 ali1535_driver.name);
163 if (retval)
164 goto exit;
165
166 if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE,
167 ali1535_driver.name)) {
168 dev_err(&dev->dev, "ALI1535_smb region 0x%x already in use!\n",
169 ali1535_smba);
170 goto exit;
171 }
172
173 /* check if whole device is enabled */
174 pci_read_config_byte(dev, SMBCFG, &temp);
175 if ((temp & ALI1535_SMBIO_EN) == 0) {
176 dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
177 goto exit_free;
178 }
179
180 /* Is SMB Host controller enabled? */
181 pci_read_config_byte(dev, SMBHSTCFG, &temp);
182 if ((temp & 1) == 0) {
183 dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
184 goto exit_free;
185 }
186
187 /* set SMB clock to 74KHz as recommended in data sheet */
188 pci_write_config_byte(dev, SMBCLK, 0x20);
189
190 /*
191 The interrupt routing for SMB is set up in register 0x77 in the
192 1533 ISA Bridge device, NOT in the 7101 device.
193 Don't bother with finding the 1533 device and reading the register.
194 if ((....... & 0x0F) == 1)
195 dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
196 */
197 pci_read_config_byte(dev, SMBREV, &temp);
198 dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
199 dev_dbg(&dev->dev, "ALI1535_smba = 0x%X\n", ali1535_smba);
200
201 retval = 0;
202 exit:
203 return retval;
204
205 exit_free:
206 release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
207 return retval;
208 }
209
210 static int ali1535_transaction(struct i2c_adapter *adap)
211 {
212 int temp;
213 int result = 0;
214 int timeout = 0;
215
216 dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
217 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
218 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
219 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
220
221 /* get status */
222 temp = inb_p(SMBHSTSTS);
223
224 /* Make sure the SMBus host is ready to start transmitting */
225 /* Check the busy bit first */
226 if (temp & ALI1535_STS_BUSY) {
227 /* If the host controller is still busy, it may have timed out
228 * in the previous transaction, resulting in a "SMBus Timeout"
229 * printk. I've tried the following to reset a stuck busy bit.
230 * 1. Reset the controller with an KILL command. (this
231 * doesn't seem to clear the controller if an external
232 * device is hung)
233 * 2. Reset the controller and the other SMBus devices with a
234 * T_OUT command. (this clears the host busy bit if an
235 * external device is hung, but it comes back upon a new
236 * access to a device)
237 * 3. Disable and reenable the controller in SMBHSTCFG. Worst
238 * case, nothing seems to work except power reset.
239 */
240
241 /* Try resetting entire SMB bus, including other devices - This
242 * may not work either - it clears the BUSY bit but then the
243 * BUSY bit may come back on when you try and use the chip
244 * again. If that's the case you are stuck.
245 */
246 dev_info(&adap->dev,
247 "Resetting entire SMB Bus to clear busy condition (%02x)\n",
248 temp);
249 outb_p(ALI1535_T_OUT, SMBHSTTYP);
250 temp = inb_p(SMBHSTSTS);
251 }
252
253 /* now check the error bits and the busy bit */
254 if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
255 /* do a clear-on-write */
256 outb_p(0xFF, SMBHSTSTS);
257 if ((temp = inb_p(SMBHSTSTS)) &
258 (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
259 /* This is probably going to be correctable only by a
260 * power reset as one of the bits now appears to be
261 * stuck */
262 /* This may be a bus or device with electrical problems. */
263 dev_err(&adap->dev,
264 "SMBus reset failed! (0x%02x) - controller or "
265 "device on bus is probably hung\n", temp);
266 return -EBUSY;
267 }
268 } else {
269 /* check and clear done bit */
270 if (temp & ALI1535_STS_DONE) {
271 outb_p(temp, SMBHSTSTS);
272 }
273 }
274
275 /* start the transaction by writing anything to the start register */
276 outb_p(0xFF, SMBHSTPORT);
277
278 /* We will always wait for a fraction of a second! */
279 timeout = 0;
280 do {
281 msleep(1);
282 temp = inb_p(SMBHSTSTS);
283 } while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
284 && (timeout++ < MAX_TIMEOUT));
285
286 /* If the SMBus is still busy, we give up */
287 if (timeout > MAX_TIMEOUT) {
288 result = -ETIMEDOUT;
289 dev_err(&adap->dev, "SMBus Timeout!\n");
290 }
291
292 if (temp & ALI1535_STS_FAIL) {
293 result = -EIO;
294 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
295 }
296
297 /* Unfortunately the ALI SMB controller maps "no response" and "bus
298 * collision" into a single bit. No reponse is the usual case so don't
299 * do a printk. This means that bus collisions go unreported.
300 */
301 if (temp & ALI1535_STS_BUSERR) {
302 result = -ENXIO;
303 dev_dbg(&adap->dev,
304 "Error: no response or bus collision ADD=%02x\n",
305 inb_p(SMBHSTADD));
306 }
307
308 /* haven't ever seen this */
309 if (temp & ALI1535_STS_DEV) {
310 result = -EIO;
311 dev_err(&adap->dev, "Error: device error\n");
312 }
313
314 /* check to see if the "command complete" indication is set */
315 if (!(temp & ALI1535_STS_DONE)) {
316 result = -ETIMEDOUT;
317 dev_err(&adap->dev, "Error: command never completed\n");
318 }
319
320 dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
321 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
322 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
323 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
324
325 /* take consequent actions for error conditions */
326 if (!(temp & ALI1535_STS_DONE)) {
327 /* issue "kill" to reset host controller */
328 outb_p(ALI1535_KILL,SMBHSTTYP);
329 outb_p(0xFF,SMBHSTSTS);
330 } else if (temp & ALI1535_STS_ERR) {
331 /* issue "timeout" to reset all devices on bus */
332 outb_p(ALI1535_T_OUT,SMBHSTTYP);
333 outb_p(0xFF,SMBHSTSTS);
334 }
335
336 return result;
337 }
338
339 /* Return negative errno on error. */
340 static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
341 unsigned short flags, char read_write, u8 command,
342 int size, union i2c_smbus_data *data)
343 {
344 int i, len;
345 int temp;
346 int timeout;
347 s32 result = 0;
348
349 /* make sure SMBus is idle */
350 temp = inb_p(SMBHSTSTS);
351 for (timeout = 0;
352 (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
353 timeout++) {
354 msleep(1);
355 temp = inb_p(SMBHSTSTS);
356 }
357 if (timeout >= MAX_TIMEOUT)
358 dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
359
360 /* clear status register (clear-on-write) */
361 outb_p(0xFF, SMBHSTSTS);
362
363 switch (size) {
364 case I2C_SMBUS_QUICK:
365 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
366 SMBHSTADD);
367 size = ALI1535_QUICK;
368 outb_p(size, SMBHSTTYP); /* output command */
369 break;
370 case I2C_SMBUS_BYTE:
371 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
372 SMBHSTADD);
373 size = ALI1535_BYTE;
374 outb_p(size, SMBHSTTYP); /* output command */
375 if (read_write == I2C_SMBUS_WRITE)
376 outb_p(command, SMBHSTCMD);
377 break;
378 case I2C_SMBUS_BYTE_DATA:
379 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
380 SMBHSTADD);
381 size = ALI1535_BYTE_DATA;
382 outb_p(size, SMBHSTTYP); /* output command */
383 outb_p(command, SMBHSTCMD);
384 if (read_write == I2C_SMBUS_WRITE)
385 outb_p(data->byte, SMBHSTDAT0);
386 break;
387 case I2C_SMBUS_WORD_DATA:
388 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
389 SMBHSTADD);
390 size = ALI1535_WORD_DATA;
391 outb_p(size, SMBHSTTYP); /* output command */
392 outb_p(command, SMBHSTCMD);
393 if (read_write == I2C_SMBUS_WRITE) {
394 outb_p(data->word & 0xff, SMBHSTDAT0);
395 outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
396 }
397 break;
398 case I2C_SMBUS_BLOCK_DATA:
399 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
400 SMBHSTADD);
401 size = ALI1535_BLOCK_DATA;
402 outb_p(size, SMBHSTTYP); /* output command */
403 outb_p(command, SMBHSTCMD);
404 if (read_write == I2C_SMBUS_WRITE) {
405 len = data->block[0];
406 if (len < 0) {
407 len = 0;
408 data->block[0] = len;
409 }
410 if (len > 32) {
411 len = 32;
412 data->block[0] = len;
413 }
414 outb_p(len, SMBHSTDAT0);
415 /* Reset SMBBLKDAT */
416 outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
417 for (i = 1; i <= len; i++)
418 outb_p(data->block[i], SMBBLKDAT);
419 }
420 break;
421 default:
422 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
423 result = -EOPNOTSUPP;
424 goto EXIT;
425 }
426
427 result = ali1535_transaction(adap);
428 if (result)
429 goto EXIT;
430
431 if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
432 result = 0;
433 goto EXIT;
434 }
435
436 switch (size) {
437 case ALI1535_BYTE: /* Result put in SMBHSTDAT0 */
438 data->byte = inb_p(SMBHSTDAT0);
439 break;
440 case ALI1535_BYTE_DATA:
441 data->byte = inb_p(SMBHSTDAT0);
442 break;
443 case ALI1535_WORD_DATA:
444 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
445 break;
446 case ALI1535_BLOCK_DATA:
447 len = inb_p(SMBHSTDAT0);
448 if (len > 32)
449 len = 32;
450 data->block[0] = len;
451 /* Reset SMBBLKDAT */
452 outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
453 for (i = 1; i <= data->block[0]; i++) {
454 data->block[i] = inb_p(SMBBLKDAT);
455 dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
456 len, i, data->block[i]);
457 }
458 break;
459 }
460 EXIT:
461 return result;
462 }
463
464
465 static u32 ali1535_func(struct i2c_adapter *adapter)
466 {
467 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
468 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
469 I2C_FUNC_SMBUS_BLOCK_DATA;
470 }
471
472 static const struct i2c_algorithm smbus_algorithm = {
473 .smbus_xfer = ali1535_access,
474 .functionality = ali1535_func,
475 };
476
477 static struct i2c_adapter ali1535_adapter = {
478 .owner = THIS_MODULE,
479 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
480 .algo = &smbus_algorithm,
481 };
482
483 static struct pci_device_id ali1535_ids[] = {
484 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
485 { },
486 };
487
488 MODULE_DEVICE_TABLE (pci, ali1535_ids);
489
490 static int __devinit ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
491 {
492 if (ali1535_setup(dev)) {
493 dev_warn(&dev->dev,
494 "ALI1535 not detected, module not inserted.\n");
495 return -ENODEV;
496 }
497
498 /* set up the sysfs linkage to our parent device */
499 ali1535_adapter.dev.parent = &dev->dev;
500
501 snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
502 "SMBus ALI1535 adapter at %04x", ali1535_smba);
503 return i2c_add_adapter(&ali1535_adapter);
504 }
505
506 static void __devexit ali1535_remove(struct pci_dev *dev)
507 {
508 i2c_del_adapter(&ali1535_adapter);
509 release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
510 }
511
512 static struct pci_driver ali1535_driver = {
513 .name = "ali1535_smbus",
514 .id_table = ali1535_ids,
515 .probe = ali1535_probe,
516 .remove = __devexit_p(ali1535_remove),
517 };
518
519 static int __init i2c_ali1535_init(void)
520 {
521 return pci_register_driver(&ali1535_driver);
522 }
523
524 static void __exit i2c_ali1535_exit(void)
525 {
526 pci_unregister_driver(&ali1535_driver);
527 }
528
529 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
530 "Philip Edelbrock <phil@netroedge.com>, "
531 "Mark D. Studebaker <mdsxyz123@yahoo.com> "
532 "and Dan Eaton <dan.eaton@rocketlogix.com>");
533 MODULE_DESCRIPTION("ALI1535 SMBus driver");
534 MODULE_LICENSE("GPL");
535
536 module_init(i2c_ali1535_init);
537 module_exit(i2c_ali1535_exit);
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