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MIPS: Yosemite, Emma: Fix off-by-two in arcs_cmdline buffer size check
[linux-2.6/linux-mips.git] / drivers / i2c / busses / i2c-ali1535.c
blobb6807db7b36f98f03ff00d15f6677906c4ddc8aa
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 <linux/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 __devinit 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 temp = inb_p(SMBHSTSTS);
258 if (temp & (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 /* start the transaction by writing anything to the start register */
275 outb_p(0xFF, SMBHSTPORT);
276
277 /* We will always wait for a fraction of a second! */
278 timeout = 0;
279 do {
280 usleep_range(1000, 2000);
281 temp = inb_p(SMBHSTSTS);
282 } while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
283 && (timeout++ < MAX_TIMEOUT));
284
285 /* If the SMBus is still busy, we give up */
286 if (timeout > MAX_TIMEOUT) {
287 result = -ETIMEDOUT;
288 dev_err(&adap->dev, "SMBus Timeout!\n");
289 }
290
291 if (temp & ALI1535_STS_FAIL) {
292 result = -EIO;
293 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
294 }
295
296 /* Unfortunately the ALI SMB controller maps "no response" and "bus
297 * collision" into a single bit. No response is the usual case so don't
298 * do a printk. This means that bus collisions go unreported.
299 */
300 if (temp & ALI1535_STS_BUSERR) {
301 result = -ENXIO;
302 dev_dbg(&adap->dev,
303 "Error: no response or bus collision ADD=%02x\n",
304 inb_p(SMBHSTADD));
305 }
306
307 /* haven't ever seen this */
308 if (temp & ALI1535_STS_DEV) {
309 result = -EIO;
310 dev_err(&adap->dev, "Error: device error\n");
311 }
312
313 /* check to see if the "command complete" indication is set */
314 if (!(temp & ALI1535_STS_DONE)) {
315 result = -ETIMEDOUT;
316 dev_err(&adap->dev, "Error: command never completed\n");
317 }
318
319 dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
320 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
321 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
322 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
323
324 /* take consequent actions for error conditions */
325 if (!(temp & ALI1535_STS_DONE)) {
326 /* issue "kill" to reset host controller */
327 outb_p(ALI1535_KILL, SMBHSTTYP);
328 outb_p(0xFF, SMBHSTSTS);
329 } else if (temp & ALI1535_STS_ERR) {
330 /* issue "timeout" to reset all devices on bus */
331 outb_p(ALI1535_T_OUT, SMBHSTTYP);
332 outb_p(0xFF, SMBHSTSTS);
333 }
334
335 return result;
336 }
337
338 /* Return negative errno on error. */
339 static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
340 unsigned short flags, char read_write, u8 command,
341 int size, union i2c_smbus_data *data)
342 {
343 int i, len;
344 int temp;
345 int timeout;
346 s32 result = 0;
347
348 /* make sure SMBus is idle */
349 temp = inb_p(SMBHSTSTS);
350 for (timeout = 0;
351 (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
352 timeout++) {
353 usleep_range(1000, 2000);
354 temp = inb_p(SMBHSTSTS);
355 }
356 if (timeout >= MAX_TIMEOUT)
357 dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
358
359 /* clear status register (clear-on-write) */
360 outb_p(0xFF, SMBHSTSTS);
361
362 switch (size) {
363 case I2C_SMBUS_QUICK:
364 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
365 SMBHSTADD);
366 size = ALI1535_QUICK;
367 outb_p(size, SMBHSTTYP); /* output command */
368 break;
369 case I2C_SMBUS_BYTE:
370 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
371 SMBHSTADD);
372 size = ALI1535_BYTE;
373 outb_p(size, SMBHSTTYP); /* output command */
374 if (read_write == I2C_SMBUS_WRITE)
375 outb_p(command, SMBHSTCMD);
376 break;
377 case I2C_SMBUS_BYTE_DATA:
378 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
379 SMBHSTADD);
380 size = ALI1535_BYTE_DATA;
381 outb_p(size, SMBHSTTYP); /* output command */
382 outb_p(command, SMBHSTCMD);
383 if (read_write == I2C_SMBUS_WRITE)
384 outb_p(data->byte, SMBHSTDAT0);
385 break;
386 case I2C_SMBUS_WORD_DATA:
387 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
388 SMBHSTADD);
389 size = ALI1535_WORD_DATA;
390 outb_p(size, SMBHSTTYP); /* output command */
391 outb_p(command, SMBHSTCMD);
392 if (read_write == I2C_SMBUS_WRITE) {
393 outb_p(data->word & 0xff, SMBHSTDAT0);
394 outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
395 }
396 break;
397 case I2C_SMBUS_BLOCK_DATA:
398 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
399 SMBHSTADD);
400 size = ALI1535_BLOCK_DATA;
401 outb_p(size, SMBHSTTYP); /* output command */
402 outb_p(command, SMBHSTCMD);
403 if (read_write == I2C_SMBUS_WRITE) {
404 len = data->block[0];
405 if (len < 0) {
406 len = 0;
407 data->block[0] = len;
408 }
409 if (len > 32) {
410 len = 32;
411 data->block[0] = len;
412 }
413 outb_p(len, SMBHSTDAT0);
414 /* Reset SMBBLKDAT */
415 outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
416 for (i = 1; i <= len; i++)
417 outb_p(data->block[i], SMBBLKDAT);
418 }
419 break;
420 default:
421 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
422 result = -EOPNOTSUPP;
423 goto EXIT;
424 }
425
426 result = ali1535_transaction(adap);
427 if (result)
428 goto EXIT;
429
430 if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
431 result = 0;
432 goto EXIT;
433 }
434
435 switch (size) {
436 case ALI1535_BYTE: /* Result put in SMBHSTDAT0 */
437 data->byte = inb_p(SMBHSTDAT0);
438 break;
439 case ALI1535_BYTE_DATA:
440 data->byte = inb_p(SMBHSTDAT0);
441 break;
442 case ALI1535_WORD_DATA:
443 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
444 break;
445 case ALI1535_BLOCK_DATA:
446 len = inb_p(SMBHSTDAT0);
447 if (len > 32)
448 len = 32;
449 data->block[0] = len;
450 /* Reset SMBBLKDAT */
451 outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
452 for (i = 1; i <= data->block[0]; i++) {
453 data->block[i] = inb_p(SMBBLKDAT);
454 dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
455 len, i, data->block[i]);
456 }
457 break;
458 }
459 EXIT:
460 return result;
461 }
462
463
464 static u32 ali1535_func(struct i2c_adapter *adapter)
465 {
466 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
467 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
468 I2C_FUNC_SMBUS_BLOCK_DATA;
469 }
470
471 static const struct i2c_algorithm smbus_algorithm = {
472 .smbus_xfer = ali1535_access,
473 .functionality = ali1535_func,
474 };
475
476 static struct i2c_adapter ali1535_adapter = {
477 .owner = THIS_MODULE,
478 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
479 .algo = &smbus_algorithm,
480 };
481
482 static DEFINE_PCI_DEVICE_TABLE(ali1535_ids) = {
483 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
484 { },
485 };
486
487 MODULE_DEVICE_TABLE(pci, ali1535_ids);
488
489 static int __devinit ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
490 {
491 if (ali1535_setup(dev)) {
492 dev_warn(&dev->dev,
493 "ALI1535 not detected, module not inserted.\n");
494 return -ENODEV;
495 }
496
497 /* set up the sysfs linkage to our parent device */
498 ali1535_adapter.dev.parent = &dev->dev;
499
500 snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
501 "SMBus ALI1535 adapter at %04x", ali1535_smba);
502 return i2c_add_adapter(&ali1535_adapter);
503 }
504
505 static void __devexit ali1535_remove(struct pci_dev *dev)
506 {
507 i2c_del_adapter(&ali1535_adapter);
508 release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
509 }
510
511 static struct pci_driver ali1535_driver = {
512 .name = "ali1535_smbus",
513 .id_table = ali1535_ids,
514 .probe = ali1535_probe,
515 .remove = __devexit_p(ali1535_remove),
516 };
517
518 static int __init i2c_ali1535_init(void)
519 {
520 return pci_register_driver(&ali1535_driver);
521 }
522
523 static void __exit i2c_ali1535_exit(void)
524 {
525 pci_unregister_driver(&ali1535_driver);
526 }
527
528 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
529 "Philip Edelbrock <phil@netroedge.com>, "
530 "Mark D. Studebaker <mdsxyz123@yahoo.com> "
531 "and Dan Eaton <dan.eaton@rocketlogix.com>");
532 MODULE_DESCRIPTION("ALI1535 SMBus driver");
533 MODULE_LICENSE("GPL");
534
535 module_init(i2c_ali1535_init);
536 module_exit(i2c_ali1535_exit);
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