1 /*
2 Copyright (c) 2002,2003 Alexander Malysh <amalysh@web.de>
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13 */
14
15 /*
16 Status: beta
17
18 Supports:
19 SIS 630
20 SIS 730
21 SIS 964
22
23 Notable differences between chips:
24 +------------------------+--------------------+-------------------+
25 | | SIS630/730 | SIS964 |
26 +------------------------+--------------------+-------------------+
27 | Clock | 14kHz/56kHz | 55.56kHz/27.78kHz |
28 | SMBus registers offset | 0x80 | 0xE0 |
29 | SMB_CNT | Bit 1 = Slave Busy | Bit 1 = Bus probe |
30 | (not used yet) | Bit 3 is reserved | Bit 3 = Last byte |
31 | SMB_PCOUNT | Offset + 0x06 | Offset + 0x14 |
32 | SMB_COUNT | 4:0 bits | 5:0 bits |
33 +------------------------+--------------------+-------------------+
34 (Other differences don't affect the functions provided by the driver)
35
36 Note: we assume there can only be one device, with one SMBus interface.
37 */
38
39 #include <linux/kernel.h>
40 #include <linux/module.h>
41 #include <linux/delay.h>
42 #include <linux/pci.h>
43 #include <linux/ioport.h>
44 #include <linux/i2c.h>
45 #include <linux/acpi.h>
46 #include <linux/io.h>
47
48 /* SIS964 id is defined here as we are the only file using it */
49 #define PCI_DEVICE_ID_SI_964 0x0964
50
51 /* SIS630/730/964 SMBus registers */
52 #define SMB_STS 0x00 /* status */
53 #define SMB_CNT 0x02 /* control */
54 #define SMBHOST_CNT 0x03 /* host control */
55 #define SMB_ADDR 0x04 /* address */
56 #define SMB_CMD 0x05 /* command */
57 #define SMB_COUNT 0x07 /* byte count */
58 #define SMB_BYTE 0x08 /* ~0x8F data byte field */
59
60 /* SMB_STS register */
61 #define BYTE_DONE_STS 0x10 /* Byte Done Status / Block Array */
62 #define SMBCOL_STS 0x04 /* Collision */
63 #define SMBERR_STS 0x02 /* Device error */
64
65 /* SMB_CNT register */
66 #define MSTO_EN 0x40 /* Host Master Timeout Enable */
67 #define SMBCLK_SEL 0x20 /* Host master clock selection */
68 #define SMB_PROBE 0x02 /* Bus Probe/Slave busy */
69 #define SMB_HOSTBUSY 0x01 /* Host Busy */
70
71 /* SMBHOST_CNT register */
72 #define SMB_KILL 0x20 /* Kill */
73 #define SMB_START 0x10 /* Start */
74
75 /* register count for request_region
76 * As we don't use SMB_PCOUNT, 20 is ok for SiS630 and SiS964
77 */
78 #define SIS630_SMB_IOREGION 20
79
80 /* PCI address constants */
81 /* acpi base address register */
82 #define SIS630_ACPI_BASE_REG 0x74
83 /* bios control register */
84 #define SIS630_BIOS_CTL_REG 0x40
85
86 /* Other settings */
87 #define MAX_TIMEOUT 500
88
89 /* SIS630 constants */
90 #define SIS630_QUICK 0x00
91 #define SIS630_BYTE 0x01
92 #define SIS630_BYTE_DATA 0x02
93 #define SIS630_WORD_DATA 0x03
94 #define SIS630_PCALL 0x04
95 #define SIS630_BLOCK_DATA 0x05
96
97 static struct pci_driver sis630_driver;
98
99 /* insmod parameters */
100 static bool high_clock;
101 static bool force;
102 module_param(high_clock, bool, 0);
103 MODULE_PARM_DESC(high_clock,
104 "Set Host Master Clock to 56KHz (default 14KHz) (SIS630/730 only).");
105 module_param(force, bool, 0);
106 MODULE_PARM_DESC(force, "Forcibly enable the SIS630. DANGEROUS!");
107
108 /* SMBus base adress */
109 static unsigned short smbus_base;
110
111 /* supported chips */
112 static int supported[] = {
113 PCI_DEVICE_ID_SI_630,
114 PCI_DEVICE_ID_SI_730,
115 PCI_DEVICE_ID_SI_760,
116 0 /* terminates the list */
117 };
118
sis630_read(u8 reg)119 static inline u8 sis630_read(u8 reg)
120 {
121 return inb(smbus_base + reg);
122 }
123
sis630_write(u8 reg,u8 data)124 static inline void sis630_write(u8 reg, u8 data)
125 {
126 outb(data, smbus_base + reg);
127 }
128
sis630_transaction_start(struct i2c_adapter * adap,int size,u8 * oldclock)129 static int sis630_transaction_start(struct i2c_adapter *adap, int size,
130 u8 *oldclock)
131 {
132 int temp;
133
134 /* Make sure the SMBus host is ready to start transmitting. */
135 temp = sis630_read(SMB_CNT);
136 if ((temp & (SMB_PROBE | SMB_HOSTBUSY)) != 0x00) {
137 dev_dbg(&adap->dev, "SMBus busy (%02x). Resetting...\n", temp);
138 /* kill smbus transaction */
139 sis630_write(SMBHOST_CNT, SMB_KILL);
140
141 temp = sis630_read(SMB_CNT);
142 if (temp & (SMB_PROBE | SMB_HOSTBUSY)) {
143 dev_dbg(&adap->dev, "Failed! (%02x)\n", temp);
144 return -EBUSY;
145 } else {
146 dev_dbg(&adap->dev, "Successful!\n");
147 }
148 }
149
150 /* save old clock, so we can prevent machine for hung */
151 *oldclock = sis630_read(SMB_CNT);
152
153 dev_dbg(&adap->dev, "saved clock 0x%02x\n", *oldclock);
154
155 /* disable timeout interrupt,
156 * set Host Master Clock to 56KHz if requested */
157 if (high_clock)
158 sis630_write(SMB_CNT, SMBCLK_SEL);
159 else
160 sis630_write(SMB_CNT, (*oldclock & ~MSTO_EN));
161
162 /* clear all sticky bits */
163 temp = sis630_read(SMB_STS);
164 sis630_write(SMB_STS, temp & 0x1e);
165
166 /* start the transaction by setting bit 4 and size */
167 sis630_write(SMBHOST_CNT, SMB_START | (size & 0x07));
168
169 return 0;
170 }
171
sis630_transaction_wait(struct i2c_adapter * adap,int size)172 static int sis630_transaction_wait(struct i2c_adapter *adap, int size)
173 {
174 int temp, result = 0, timeout = 0;
175
176 /* We will always wait for a fraction of a second! */
177 do {
178 msleep(1);
179 temp = sis630_read(SMB_STS);
180 /* check if block transmitted */
181 if (size == SIS630_BLOCK_DATA && (temp & BYTE_DONE_STS))
182 break;
183 } while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
184
185 /* If the SMBus is still busy, we give up */
186 if (timeout > MAX_TIMEOUT) {
187 dev_dbg(&adap->dev, "SMBus Timeout!\n");
188 result = -ETIMEDOUT;
189 }
190
191 if (temp & SMBERR_STS) {
192 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
193 result = -ENXIO;
194 }
195
196 if (temp & SMBCOL_STS) {
197 dev_err(&adap->dev, "Bus collision!\n");
198 result = -EAGAIN;
199 }
200
201 return result;
202 }
203
sis630_transaction_end(struct i2c_adapter * adap,u8 oldclock)204 static void sis630_transaction_end(struct i2c_adapter *adap, u8 oldclock)
205 {
206 /* clear all status "sticky" bits */
207 sis630_write(SMB_STS, 0xFF);
208
209 dev_dbg(&adap->dev,
210 "SMB_CNT before clock restore 0x%02x\n", sis630_read(SMB_CNT));
211
212 /*
213 * restore old Host Master Clock if high_clock is set
214 * and oldclock was not 56KHz
215 */
216 if (high_clock && !(oldclock & SMBCLK_SEL))
217 sis630_write(SMB_CNT, sis630_read(SMB_CNT) & ~SMBCLK_SEL);
218
219 dev_dbg(&adap->dev,
220 "SMB_CNT after clock restore 0x%02x\n", sis630_read(SMB_CNT));
221 }
222
sis630_transaction(struct i2c_adapter * adap,int size)223 static int sis630_transaction(struct i2c_adapter *adap, int size)
224 {
225 int result = 0;
226 u8 oldclock = 0;
227
228 result = sis630_transaction_start(adap, size, &oldclock);
229 if (!result) {
230 result = sis630_transaction_wait(adap, size);
231 sis630_transaction_end(adap, oldclock);
232 }
233
234 return result;
235 }
236
sis630_block_data(struct i2c_adapter * adap,union i2c_smbus_data * data,int read_write)237 static int sis630_block_data(struct i2c_adapter *adap,
238 union i2c_smbus_data *data, int read_write)
239 {
240 int i, len = 0, rc = 0;
241 u8 oldclock = 0;
242
243 if (read_write == I2C_SMBUS_WRITE) {
244 len = data->block[0];
245 if (len < 0)
246 len = 0;
247 else if (len > 32)
248 len = 32;
249 sis630_write(SMB_COUNT, len);
250 for (i = 1; i <= len; i++) {
251 dev_dbg(&adap->dev,
252 "set data 0x%02x\n", data->block[i]);
253 /* set data */
254 sis630_write(SMB_BYTE + (i - 1) % 8, data->block[i]);
255 if (i == 8 || (len < 8 && i == len)) {
256 dev_dbg(&adap->dev,
257 "start trans len=%d i=%d\n", len, i);
258 /* first transaction */
259 rc = sis630_transaction_start(adap,
260 SIS630_BLOCK_DATA, &oldclock);
261 if (rc)
262 return rc;
263 } else if ((i - 1) % 8 == 7 || i == len) {
264 dev_dbg(&adap->dev,
265 "trans_wait len=%d i=%d\n", len, i);
266 if (i > 8) {
267 dev_dbg(&adap->dev,
268 "clear smbary_sts"
269 " len=%d i=%d\n", len, i);
270 /*
271 If this is not first transaction,
272 we must clear sticky bit.
273 clear SMBARY_STS
274 */
275 sis630_write(SMB_STS, BYTE_DONE_STS);
276 }
277 rc = sis630_transaction_wait(adap,
278 SIS630_BLOCK_DATA);
279 if (rc) {
280 dev_dbg(&adap->dev,
281 "trans_wait failed\n");
282 break;
283 }
284 }
285 }
286 } else {
287 /* read request */
288 data->block[0] = len = 0;
289 rc = sis630_transaction_start(adap,
290 SIS630_BLOCK_DATA, &oldclock);
291 if (rc)
292 return rc;
293 do {
294 rc = sis630_transaction_wait(adap, SIS630_BLOCK_DATA);
295 if (rc) {
296 dev_dbg(&adap->dev, "trans_wait failed\n");
297 break;
298 }
299 /* if this first transaction then read byte count */
300 if (len == 0)
301 data->block[0] = sis630_read(SMB_COUNT);
302
303 /* just to be sure */
304 if (data->block[0] > 32)
305 data->block[0] = 32;
306
307 dev_dbg(&adap->dev,
308 "block data read len=0x%x\n", data->block[0]);
309
310 for (i = 0; i < 8 && len < data->block[0]; i++, len++) {
311 dev_dbg(&adap->dev,
312 "read i=%d len=%d\n", i, len);
313 data->block[len + 1] = sis630_read(SMB_BYTE +
314 i);
315 }
316
317 dev_dbg(&adap->dev,
318 "clear smbary_sts len=%d i=%d\n", len, i);
319
320 /* clear SMBARY_STS */
321 sis630_write(SMB_STS, BYTE_DONE_STS);
322 } while (len < data->block[0]);
323 }
324
325 sis630_transaction_end(adap, oldclock);
326
327 return rc;
328 }
329
330 /* Return negative errno on error. */
sis630_access(struct i2c_adapter * adap,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)331 static s32 sis630_access(struct i2c_adapter *adap, u16 addr,
332 unsigned short flags, char read_write,
333 u8 command, int size, union i2c_smbus_data *data)
334 {
335 int status;
336
337 switch (size) {
338 case I2C_SMBUS_QUICK:
339 sis630_write(SMB_ADDR,
340 ((addr & 0x7f) << 1) | (read_write & 0x01));
341 size = SIS630_QUICK;
342 break;
343 case I2C_SMBUS_BYTE:
344 sis630_write(SMB_ADDR,
345 ((addr & 0x7f) << 1) | (read_write & 0x01));
346 if (read_write == I2C_SMBUS_WRITE)
347 sis630_write(SMB_CMD, command);
348 size = SIS630_BYTE;
349 break;
350 case I2C_SMBUS_BYTE_DATA:
351 sis630_write(SMB_ADDR,
352 ((addr & 0x7f) << 1) | (read_write & 0x01));
353 sis630_write(SMB_CMD, command);
354 if (read_write == I2C_SMBUS_WRITE)
355 sis630_write(SMB_BYTE, data->byte);
356 size = SIS630_BYTE_DATA;
357 break;
358 case I2C_SMBUS_PROC_CALL:
359 case I2C_SMBUS_WORD_DATA:
360 sis630_write(SMB_ADDR,
361 ((addr & 0x7f) << 1) | (read_write & 0x01));
362 sis630_write(SMB_CMD, command);
363 if (read_write == I2C_SMBUS_WRITE) {
364 sis630_write(SMB_BYTE, data->word & 0xff);
365 sis630_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8);
366 }
367 size = (size == I2C_SMBUS_PROC_CALL ?
368 SIS630_PCALL : SIS630_WORD_DATA);
369 break;
370 case I2C_SMBUS_BLOCK_DATA:
371 sis630_write(SMB_ADDR,
372 ((addr & 0x7f) << 1) | (read_write & 0x01));
373 sis630_write(SMB_CMD, command);
374 size = SIS630_BLOCK_DATA;
375 return sis630_block_data(adap, data, read_write);
376 default:
377 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
378 return -EOPNOTSUPP;
379 }
380
381 status = sis630_transaction(adap, size);
382 if (status)
383 return status;
384
385 if ((size != SIS630_PCALL) &&
386 ((read_write == I2C_SMBUS_WRITE) || (size == SIS630_QUICK))) {
387 return 0;
388 }
389
390 switch (size) {
391 case SIS630_BYTE:
392 case SIS630_BYTE_DATA:
393 data->byte = sis630_read(SMB_BYTE);
394 break;
395 case SIS630_PCALL:
396 case SIS630_WORD_DATA:
397 data->word = sis630_read(SMB_BYTE) +
398 (sis630_read(SMB_BYTE + 1) << 8);
399 break;
400 }
401
402 return 0;
403 }
404
sis630_func(struct i2c_adapter * adapter)405 static u32 sis630_func(struct i2c_adapter *adapter)
406 {
407 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
408 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
409 I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_DATA;
410 }
411
sis630_setup(struct pci_dev * sis630_dev)412 static int sis630_setup(struct pci_dev *sis630_dev)
413 {
414 unsigned char b;
415 struct pci_dev *dummy = NULL;
416 int retval, i;
417 /* acpi base address */
418 unsigned short acpi_base;
419
420 /* check for supported SiS devices */
421 for (i = 0; supported[i] > 0; i++) {
422 dummy = pci_get_device(PCI_VENDOR_ID_SI, supported[i], dummy);
423 if (dummy)
424 break; /* found */
425 }
426
427 if (dummy) {
428 pci_dev_put(dummy);
429 } else if (force) {
430 dev_err(&sis630_dev->dev,
431 "WARNING: Can't detect SIS630 compatible device, but "
432 "loading because of force option enabled\n");
433 } else {
434 return -ENODEV;
435 }
436
437 /*
438 Enable ACPI first , so we can accsess reg 74-75
439 in acpi io space and read acpi base addr
440 */
441 if (pci_read_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, &b)) {
442 dev_err(&sis630_dev->dev, "Error: Can't read bios ctl reg\n");
443 retval = -ENODEV;
444 goto exit;
445 }
446 /* if ACPI already enabled , do nothing */
447 if (!(b & 0x80) &&
448 pci_write_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, b | 0x80)) {
449 dev_err(&sis630_dev->dev, "Error: Can't enable ACPI\n");
450 retval = -ENODEV;
451 goto exit;
452 }
453
454 /* Determine the ACPI base address */
455 if (pci_read_config_word(sis630_dev,
456 SIS630_ACPI_BASE_REG, &acpi_base)) {
457 dev_err(&sis630_dev->dev,
458 "Error: Can't determine ACPI base address\n");
459 retval = -ENODEV;
460 goto exit;
461 }
462
463 dev_dbg(&sis630_dev->dev, "ACPI base at 0x%04hx\n", acpi_base);
464
465 if (supported[i] == PCI_DEVICE_ID_SI_760)
466 smbus_base = acpi_base + 0xE0;
467 else
468 smbus_base = acpi_base + 0x80;
469
470 dev_dbg(&sis630_dev->dev, "SMBus base at 0x%04hx\n", smbus_base);
471
472 retval = acpi_check_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION,
473 sis630_driver.name);
474 if (retval)
475 goto exit;
476
477 /* Everything is happy, let's grab the memory and set things up. */
478 if (!request_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION,
479 sis630_driver.name)) {
480 dev_err(&sis630_dev->dev,
481 "I/O Region 0x%04hx-0x%04hx for SMBus already in use.\n",
482 smbus_base + SMB_STS,
483 smbus_base + SMB_STS + SIS630_SMB_IOREGION - 1);
484 retval = -EBUSY;
485 goto exit;
486 }
487
488 retval = 0;
489
490 exit:
491 if (retval)
492 smbus_base = 0;
493 return retval;
494 }
495
496
497 static const struct i2c_algorithm smbus_algorithm = {
498 .smbus_xfer = sis630_access,
499 .functionality = sis630_func,
500 };
501
502 static struct i2c_adapter sis630_adapter = {
503 .owner = THIS_MODULE,
504 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
505 .algo = &smbus_algorithm,
506 .retries = 3
507 };
508
509 static const struct pci_device_id sis630_ids[] = {
510 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
511 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_LPC) },
512 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_964) },
513 { 0, }
514 };
515
516 MODULE_DEVICE_TABLE(pci, sis630_ids);
517
sis630_probe(struct pci_dev * dev,const struct pci_device_id * id)518 static int sis630_probe(struct pci_dev *dev, const struct pci_device_id *id)
519 {
520 if (sis630_setup(dev)) {
521 dev_err(&dev->dev,
522 "SIS630 compatible bus not detected, "
523 "module not inserted.\n");
524 return -ENODEV;
525 }
526
527 /* set up the sysfs linkage to our parent device */
528 sis630_adapter.dev.parent = &dev->dev;
529
530 snprintf(sis630_adapter.name, sizeof(sis630_adapter.name),
531 "SMBus SIS630 adapter at %04hx", smbus_base + SMB_STS);
532
533 return i2c_add_adapter(&sis630_adapter);
534 }
535
sis630_remove(struct pci_dev * dev)536 static void sis630_remove(struct pci_dev *dev)
537 {
538 if (smbus_base) {
539 i2c_del_adapter(&sis630_adapter);
540 release_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION);
541 smbus_base = 0;
542 }
543 }
544
545
546 static struct pci_driver sis630_driver = {
547 .name = "sis630_smbus",
548 .id_table = sis630_ids,
549 .probe = sis630_probe,
550 .remove = sis630_remove,
551 };
552
553 module_pci_driver(sis630_driver);
554
555 MODULE_LICENSE("GPL");
556 MODULE_AUTHOR("Alexander Malysh <amalysh@web.de>");
557 MODULE_DESCRIPTION("SIS630 SMBus driver");
558