1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 Copyright (c) 2002,2003 Alexander Malysh <amalysh@web.de>
4
5 */
6
7 /*
8 Status: beta
9
10 Supports:
11 SIS 630
12 SIS 730
13 SIS 964
14
15 Notable differences between chips:
16 +------------------------+--------------------+-------------------+
17 | | SIS630/730 | SIS964 |
18 +------------------------+--------------------+-------------------+
19 | Clock | 14kHz/56kHz | 55.56kHz/27.78kHz |
20 | SMBus registers offset | 0x80 | 0xE0 |
21 | SMB_CNT | Bit 1 = Slave Busy | Bit 1 = Bus probe |
22 | (not used yet) | Bit 3 is reserved | Bit 3 = Last byte |
23 | SMB_PCOUNT | Offset + 0x06 | Offset + 0x14 |
24 | SMB_COUNT | 4:0 bits | 5:0 bits |
25 +------------------------+--------------------+-------------------+
26 (Other differences don't affect the functions provided by the driver)
27
28 Note: we assume there can only be one device, with one SMBus interface.
29 */
30
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/delay.h>
34 #include <linux/pci.h>
35 #include <linux/ioport.h>
36 #include <linux/i2c.h>
37 #include <linux/acpi.h>
38 #include <linux/io.h>
39
40 /* SIS964 id is defined here as we are the only file using it */
41 #define PCI_DEVICE_ID_SI_964 0x0964
42
43 /* SIS630/730/964 SMBus registers */
44 #define SMB_STS 0x00 /* status */
45 #define SMB_CNT 0x02 /* control */
46 #define SMBHOST_CNT 0x03 /* host control */
47 #define SMB_ADDR 0x04 /* address */
48 #define SMB_CMD 0x05 /* command */
49 #define SMB_COUNT 0x07 /* byte count */
50 #define SMB_BYTE 0x08 /* ~0x8F data byte field */
51
52 /* SMB_STS register */
53 #define BYTE_DONE_STS 0x10 /* Byte Done Status / Block Array */
54 #define SMBCOL_STS 0x04 /* Collision */
55 #define SMBERR_STS 0x02 /* Device error */
56
57 /* SMB_CNT register */
58 #define MSTO_EN 0x40 /* Host Master Timeout Enable */
59 #define SMBCLK_SEL 0x20 /* Host master clock selection */
60 #define SMB_PROBE 0x02 /* Bus Probe/Slave busy */
61 #define SMB_HOSTBUSY 0x01 /* Host Busy */
62
63 /* SMBHOST_CNT register */
64 #define SMB_KILL 0x20 /* Kill */
65 #define SMB_START 0x10 /* Start */
66
67 /* register count for request_region
68 * As we don't use SMB_PCOUNT, 20 is ok for SiS630 and SiS964
69 */
70 #define SIS630_SMB_IOREGION 20
71
72 /* PCI address constants */
73 /* acpi base address register */
74 #define SIS630_ACPI_BASE_REG 0x74
75 /* bios control register */
76 #define SIS630_BIOS_CTL_REG 0x40
77
78 /* Other settings */
79 #define MAX_TIMEOUT 500
80
81 /* SIS630 constants */
82 #define SIS630_QUICK 0x00
83 #define SIS630_BYTE 0x01
84 #define SIS630_BYTE_DATA 0x02
85 #define SIS630_WORD_DATA 0x03
86 #define SIS630_PCALL 0x04
87 #define SIS630_BLOCK_DATA 0x05
88
89 static struct pci_driver sis630_driver;
90
91 /* insmod parameters */
92 static bool high_clock;
93 static bool force;
94 module_param(high_clock, bool, 0);
95 MODULE_PARM_DESC(high_clock,
96 "Set Host Master Clock to 56KHz (default 14KHz) (SIS630/730 only).");
97 module_param(force, bool, 0);
98 MODULE_PARM_DESC(force, "Forcibly enable the SIS630. DANGEROUS!");
99
100 /* SMBus base address */
101 static unsigned short smbus_base;
102
103 /* supported chips */
104 static int supported[] = {
105 PCI_DEVICE_ID_SI_630,
106 PCI_DEVICE_ID_SI_730,
107 PCI_DEVICE_ID_SI_760,
108 0 /* terminates the list */
109 };
110
sis630_read(u8 reg)111 static inline u8 sis630_read(u8 reg)
112 {
113 return inb(smbus_base + reg);
114 }
115
sis630_write(u8 reg,u8 data)116 static inline void sis630_write(u8 reg, u8 data)
117 {
118 outb(data, smbus_base + reg);
119 }
120
sis630_transaction_start(struct i2c_adapter * adap,int size,u8 * oldclock)121 static int sis630_transaction_start(struct i2c_adapter *adap, int size,
122 u8 *oldclock)
123 {
124 int temp;
125
126 /* Make sure the SMBus host is ready to start transmitting. */
127 temp = sis630_read(SMB_CNT);
128 if ((temp & (SMB_PROBE | SMB_HOSTBUSY)) != 0x00) {
129 dev_dbg(&adap->dev, "SMBus busy (%02x). Resetting...\n", temp);
130 /* kill smbus transaction */
131 sis630_write(SMBHOST_CNT, SMB_KILL);
132
133 temp = sis630_read(SMB_CNT);
134 if (temp & (SMB_PROBE | SMB_HOSTBUSY)) {
135 dev_dbg(&adap->dev, "Failed! (%02x)\n", temp);
136 return -EBUSY;
137 } else {
138 dev_dbg(&adap->dev, "Successful!\n");
139 }
140 }
141
142 /* save old clock, so we can prevent machine for hung */
143 *oldclock = sis630_read(SMB_CNT);
144
145 dev_dbg(&adap->dev, "saved clock 0x%02x\n", *oldclock);
146
147 /* disable timeout interrupt,
148 * set Host Master Clock to 56KHz if requested */
149 if (high_clock)
150 sis630_write(SMB_CNT, SMBCLK_SEL);
151 else
152 sis630_write(SMB_CNT, (*oldclock & ~MSTO_EN));
153
154 /* clear all sticky bits */
155 temp = sis630_read(SMB_STS);
156 sis630_write(SMB_STS, temp & 0x1e);
157
158 /* start the transaction by setting bit 4 and size */
159 sis630_write(SMBHOST_CNT, SMB_START | (size & 0x07));
160
161 return 0;
162 }
163
sis630_transaction_wait(struct i2c_adapter * adap,int size)164 static int sis630_transaction_wait(struct i2c_adapter *adap, int size)
165 {
166 int temp, result = 0, timeout = 0;
167
168 /* We will always wait for a fraction of a second! */
169 do {
170 msleep(1);
171 temp = sis630_read(SMB_STS);
172 /* check if block transmitted */
173 if (size == SIS630_BLOCK_DATA && (temp & BYTE_DONE_STS))
174 break;
175 } while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
176
177 /* If the SMBus is still busy, we give up */
178 if (timeout > MAX_TIMEOUT) {
179 dev_dbg(&adap->dev, "SMBus Timeout!\n");
180 result = -ETIMEDOUT;
181 }
182
183 if (temp & SMBERR_STS) {
184 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
185 result = -ENXIO;
186 }
187
188 if (temp & SMBCOL_STS) {
189 dev_err(&adap->dev, "Bus collision!\n");
190 result = -EAGAIN;
191 }
192
193 return result;
194 }
195
sis630_transaction_end(struct i2c_adapter * adap,u8 oldclock)196 static void sis630_transaction_end(struct i2c_adapter *adap, u8 oldclock)
197 {
198 /* clear all status "sticky" bits */
199 sis630_write(SMB_STS, 0xFF);
200
201 dev_dbg(&adap->dev,
202 "SMB_CNT before clock restore 0x%02x\n", sis630_read(SMB_CNT));
203
204 /*
205 * restore old Host Master Clock if high_clock is set
206 * and oldclock was not 56KHz
207 */
208 if (high_clock && !(oldclock & SMBCLK_SEL))
209 sis630_write(SMB_CNT, sis630_read(SMB_CNT) & ~SMBCLK_SEL);
210
211 dev_dbg(&adap->dev,
212 "SMB_CNT after clock restore 0x%02x\n", sis630_read(SMB_CNT));
213 }
214
sis630_transaction(struct i2c_adapter * adap,int size)215 static int sis630_transaction(struct i2c_adapter *adap, int size)
216 {
217 int result = 0;
218 u8 oldclock = 0;
219
220 result = sis630_transaction_start(adap, size, &oldclock);
221 if (!result) {
222 result = sis630_transaction_wait(adap, size);
223 sis630_transaction_end(adap, oldclock);
224 }
225
226 return result;
227 }
228
sis630_block_data(struct i2c_adapter * adap,union i2c_smbus_data * data,int read_write)229 static int sis630_block_data(struct i2c_adapter *adap,
230 union i2c_smbus_data *data, int read_write)
231 {
232 int i, len = 0, rc = 0;
233 u8 oldclock = 0;
234
235 if (read_write == I2C_SMBUS_WRITE) {
236 len = data->block[0];
237 if (len < 0)
238 len = 0;
239 else if (len > 32)
240 len = 32;
241 sis630_write(SMB_COUNT, len);
242 for (i = 1; i <= len; i++) {
243 dev_dbg(&adap->dev,
244 "set data 0x%02x\n", data->block[i]);
245 /* set data */
246 sis630_write(SMB_BYTE + (i - 1) % 8, data->block[i]);
247 if (i == 8 || (len < 8 && i == len)) {
248 dev_dbg(&adap->dev,
249 "start trans len=%d i=%d\n", len, i);
250 /* first transaction */
251 rc = sis630_transaction_start(adap,
252 SIS630_BLOCK_DATA, &oldclock);
253 if (rc)
254 return rc;
255 } else if ((i - 1) % 8 == 7 || i == len) {
256 dev_dbg(&adap->dev,
257 "trans_wait len=%d i=%d\n", len, i);
258 if (i > 8) {
259 dev_dbg(&adap->dev,
260 "clear smbary_sts"
261 " len=%d i=%d\n", len, i);
262 /*
263 If this is not first transaction,
264 we must clear sticky bit.
265 clear SMBARY_STS
266 */
267 sis630_write(SMB_STS, BYTE_DONE_STS);
268 }
269 rc = sis630_transaction_wait(adap,
270 SIS630_BLOCK_DATA);
271 if (rc) {
272 dev_dbg(&adap->dev,
273 "trans_wait failed\n");
274 break;
275 }
276 }
277 }
278 } else {
279 /* read request */
280 data->block[0] = len = 0;
281 rc = sis630_transaction_start(adap,
282 SIS630_BLOCK_DATA, &oldclock);
283 if (rc)
284 return rc;
285 do {
286 rc = sis630_transaction_wait(adap, SIS630_BLOCK_DATA);
287 if (rc) {
288 dev_dbg(&adap->dev, "trans_wait failed\n");
289 break;
290 }
291 /* if this first transaction then read byte count */
292 if (len == 0)
293 data->block[0] = sis630_read(SMB_COUNT);
294
295 /* just to be sure */
296 if (data->block[0] > 32)
297 data->block[0] = 32;
298
299 dev_dbg(&adap->dev,
300 "block data read len=0x%x\n", data->block[0]);
301
302 for (i = 0; i < 8 && len < data->block[0]; i++, len++) {
303 dev_dbg(&adap->dev,
304 "read i=%d len=%d\n", i, len);
305 data->block[len + 1] = sis630_read(SMB_BYTE +
306 i);
307 }
308
309 dev_dbg(&adap->dev,
310 "clear smbary_sts len=%d i=%d\n", len, i);
311
312 /* clear SMBARY_STS */
313 sis630_write(SMB_STS, BYTE_DONE_STS);
314 } while (len < data->block[0]);
315 }
316
317 sis630_transaction_end(adap, oldclock);
318
319 return rc;
320 }
321
322 /* 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)323 static s32 sis630_access(struct i2c_adapter *adap, u16 addr,
324 unsigned short flags, char read_write,
325 u8 command, int size, union i2c_smbus_data *data)
326 {
327 int status;
328
329 switch (size) {
330 case I2C_SMBUS_QUICK:
331 sis630_write(SMB_ADDR,
332 ((addr & 0x7f) << 1) | (read_write & 0x01));
333 size = SIS630_QUICK;
334 break;
335 case I2C_SMBUS_BYTE:
336 sis630_write(SMB_ADDR,
337 ((addr & 0x7f) << 1) | (read_write & 0x01));
338 if (read_write == I2C_SMBUS_WRITE)
339 sis630_write(SMB_CMD, command);
340 size = SIS630_BYTE;
341 break;
342 case I2C_SMBUS_BYTE_DATA:
343 sis630_write(SMB_ADDR,
344 ((addr & 0x7f) << 1) | (read_write & 0x01));
345 sis630_write(SMB_CMD, command);
346 if (read_write == I2C_SMBUS_WRITE)
347 sis630_write(SMB_BYTE, data->byte);
348 size = SIS630_BYTE_DATA;
349 break;
350 case I2C_SMBUS_PROC_CALL:
351 case I2C_SMBUS_WORD_DATA:
352 sis630_write(SMB_ADDR,
353 ((addr & 0x7f) << 1) | (read_write & 0x01));
354 sis630_write(SMB_CMD, command);
355 if (read_write == I2C_SMBUS_WRITE) {
356 sis630_write(SMB_BYTE, data->word & 0xff);
357 sis630_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8);
358 }
359 size = (size == I2C_SMBUS_PROC_CALL ?
360 SIS630_PCALL : SIS630_WORD_DATA);
361 break;
362 case I2C_SMBUS_BLOCK_DATA:
363 sis630_write(SMB_ADDR,
364 ((addr & 0x7f) << 1) | (read_write & 0x01));
365 sis630_write(SMB_CMD, command);
366 size = SIS630_BLOCK_DATA;
367 return sis630_block_data(adap, data, read_write);
368 default:
369 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
370 return -EOPNOTSUPP;
371 }
372
373 status = sis630_transaction(adap, size);
374 if (status)
375 return status;
376
377 if ((size != SIS630_PCALL) &&
378 ((read_write == I2C_SMBUS_WRITE) || (size == SIS630_QUICK))) {
379 return 0;
380 }
381
382 switch (size) {
383 case SIS630_BYTE:
384 case SIS630_BYTE_DATA:
385 data->byte = sis630_read(SMB_BYTE);
386 break;
387 case SIS630_PCALL:
388 case SIS630_WORD_DATA:
389 data->word = sis630_read(SMB_BYTE) +
390 (sis630_read(SMB_BYTE + 1) << 8);
391 break;
392 }
393
394 return 0;
395 }
396
sis630_func(struct i2c_adapter * adapter)397 static u32 sis630_func(struct i2c_adapter *adapter)
398 {
399 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
400 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
401 I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_DATA;
402 }
403
sis630_setup(struct pci_dev * sis630_dev)404 static int sis630_setup(struct pci_dev *sis630_dev)
405 {
406 unsigned char b;
407 struct pci_dev *dummy = NULL;
408 int retval, i;
409 /* acpi base address */
410 unsigned short acpi_base;
411
412 /* check for supported SiS devices */
413 for (i = 0; supported[i] > 0; i++) {
414 dummy = pci_get_device(PCI_VENDOR_ID_SI, supported[i], dummy);
415 if (dummy)
416 break; /* found */
417 }
418
419 if (dummy) {
420 pci_dev_put(dummy);
421 } else if (force) {
422 dev_err(&sis630_dev->dev,
423 "WARNING: Can't detect SIS630 compatible device, but "
424 "loading because of force option enabled\n");
425 } else {
426 return -ENODEV;
427 }
428
429 /*
430 Enable ACPI first , so we can accsess reg 74-75
431 in acpi io space and read acpi base addr
432 */
433 if (pci_read_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, &b)) {
434 dev_err(&sis630_dev->dev, "Error: Can't read bios ctl reg\n");
435 retval = -ENODEV;
436 goto exit;
437 }
438 /* if ACPI already enabled , do nothing */
439 if (!(b & 0x80) &&
440 pci_write_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, b | 0x80)) {
441 dev_err(&sis630_dev->dev, "Error: Can't enable ACPI\n");
442 retval = -ENODEV;
443 goto exit;
444 }
445
446 /* Determine the ACPI base address */
447 if (pci_read_config_word(sis630_dev,
448 SIS630_ACPI_BASE_REG, &acpi_base)) {
449 dev_err(&sis630_dev->dev,
450 "Error: Can't determine ACPI base address\n");
451 retval = -ENODEV;
452 goto exit;
453 }
454
455 dev_dbg(&sis630_dev->dev, "ACPI base at 0x%04hx\n", acpi_base);
456
457 if (supported[i] == PCI_DEVICE_ID_SI_760)
458 smbus_base = acpi_base + 0xE0;
459 else
460 smbus_base = acpi_base + 0x80;
461
462 dev_dbg(&sis630_dev->dev, "SMBus base at 0x%04hx\n", smbus_base);
463
464 retval = acpi_check_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION,
465 sis630_driver.name);
466 if (retval)
467 goto exit;
468
469 /* Everything is happy, let's grab the memory and set things up. */
470 if (!request_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION,
471 sis630_driver.name)) {
472 dev_err(&sis630_dev->dev,
473 "I/O Region 0x%04x-0x%04x for SMBus already in use.\n",
474 smbus_base + SMB_STS,
475 smbus_base + SMB_STS + SIS630_SMB_IOREGION - 1);
476 retval = -EBUSY;
477 goto exit;
478 }
479
480 retval = 0;
481
482 exit:
483 if (retval)
484 smbus_base = 0;
485 return retval;
486 }
487
488
489 static const struct i2c_algorithm smbus_algorithm = {
490 .smbus_xfer = sis630_access,
491 .functionality = sis630_func,
492 };
493
494 static struct i2c_adapter sis630_adapter = {
495 .owner = THIS_MODULE,
496 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
497 .algo = &smbus_algorithm,
498 .retries = 3
499 };
500
501 static const struct pci_device_id sis630_ids[] = {
502 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
503 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_LPC) },
504 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_964) },
505 { 0, }
506 };
507
508 MODULE_DEVICE_TABLE(pci, sis630_ids);
509
sis630_probe(struct pci_dev * dev,const struct pci_device_id * id)510 static int sis630_probe(struct pci_dev *dev, const struct pci_device_id *id)
511 {
512 if (sis630_setup(dev)) {
513 dev_err(&dev->dev,
514 "SIS630 compatible bus not detected, "
515 "module not inserted.\n");
516 return -ENODEV;
517 }
518
519 /* set up the sysfs linkage to our parent device */
520 sis630_adapter.dev.parent = &dev->dev;
521
522 snprintf(sis630_adapter.name, sizeof(sis630_adapter.name),
523 "SMBus SIS630 adapter at %04x", smbus_base + SMB_STS);
524
525 return i2c_add_adapter(&sis630_adapter);
526 }
527
sis630_remove(struct pci_dev * dev)528 static void sis630_remove(struct pci_dev *dev)
529 {
530 if (smbus_base) {
531 i2c_del_adapter(&sis630_adapter);
532 release_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION);
533 smbus_base = 0;
534 }
535 }
536
537
538 static struct pci_driver sis630_driver = {
539 .name = "sis630_smbus",
540 .id_table = sis630_ids,
541 .probe = sis630_probe,
542 .remove = sis630_remove,
543 };
544
545 module_pci_driver(sis630_driver);
546
547 MODULE_LICENSE("GPL");
548 MODULE_AUTHOR("Alexander Malysh <amalysh@web.de>");
549 MODULE_DESCRIPTION("SIS630 SMBus driver");
550
