1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2000 Frodo Looijaard <frodol@dds.nl>,
4 * Philip Edelbrock <phil@netroedge.com>,
5 * Mark D. Studebaker <mdsxyz123@yahoo.com>,
6 * Dan Eaton <dan.eaton@rocketlogix.com> and
7 * Stephen Rousset <stephen.rousset@rocketlogix.com>
8 */
9
10 /*
11 This is the driver for the SMB Host controller on
12 Acer Labs Inc. (ALI) M1535 South Bridge.
13
14 The M1535 is a South bridge for portable systems.
15 It is very similar to the M15x3 South bridges also produced
16 by Acer Labs Inc. Some of the registers within the part
17 have moved and some have been redefined slightly. Additionally,
18 the sequencing of the SMBus transactions has been modified
19 to be more consistent with the sequencing recommended by
20 the manufacturer and observed through testing. These
21 changes are reflected in this driver and can be identified
22 by comparing this driver to the i2c-ali15x3 driver.
23 For an overview of these chips see http://www.acerlabs.com
24
25 The SMB controller is part of the 7101 device, which is an
26 ACPI-compliant Power Management Unit (PMU).
27
28 The whole 7101 device has to be enabled for the SMB to work.
29 You can't just enable the SMB alone.
30 The SMB and the ACPI have separate I/O spaces.
31 We make sure that the SMB is enabled. We leave the ACPI alone.
32
33 This driver controls the SMB Host only.
34
35 This driver does not use interrupts.
36 */
37
38
39 /* Note: we assume there can only be one ALI1535, with one SMBus interface */
40
41 #include <linux/module.h>
42 #include <linux/pci.h>
43 #include <linux/kernel.h>
44 #include <linux/stddef.h>
45 #include <linux/delay.h>
46 #include <linux/ioport.h>
47 #include <linux/i2c.h>
48 #include <linux/acpi.h>
49 #include <linux/io.h>
50
51
52 /* ALI1535 SMBus address offsets */
53 #define SMBHSTSTS (0 + ali1535_smba)
54 #define SMBHSTTYP (1 + ali1535_smba)
55 #define SMBHSTPORT (2 + ali1535_smba)
56 #define SMBHSTCMD (7 + ali1535_smba)
57 #define SMBHSTADD (3 + ali1535_smba)
58 #define SMBHSTDAT0 (4 + ali1535_smba)
59 #define SMBHSTDAT1 (5 + ali1535_smba)
60 #define SMBBLKDAT (6 + ali1535_smba)
61
62 /* PCI Address Constants */
63 #define SMBCOM 0x004
64 #define SMBREV 0x008
65 #define SMBCFG 0x0D1
66 #define SMBBA 0x0E2
67 #define SMBHSTCFG 0x0F0
68 #define SMBCLK 0x0F2
69
70 /* Other settings */
71 #define MAX_TIMEOUT 500 /* times 1/100 sec */
72 #define ALI1535_SMB_IOSIZE 32
73
74 #define ALI1535_SMB_DEFAULTBASE 0x8040
75
76 /* ALI1535 address lock bits */
77 #define ALI1535_LOCK 0x06 /* dwe */
78
79 /* ALI1535 command constants */
80 #define ALI1535_QUICK 0x00
81 #define ALI1535_BYTE 0x10
82 #define ALI1535_BYTE_DATA 0x20
83 #define ALI1535_WORD_DATA 0x30
84 #define ALI1535_BLOCK_DATA 0x40
85 #define ALI1535_I2C_READ 0x60
86
87 #define ALI1535_DEV10B_EN 0x80 /* Enable 10-bit addressing in */
88 /* I2C read */
89 #define ALI1535_T_OUT 0x08 /* Time-out Command (write) */
90 #define ALI1535_A_HIGH_BIT9 0x08 /* Bit 9 of 10-bit address in */
91 /* Alert-Response-Address */
92 /* (read) */
93 #define ALI1535_KILL 0x04 /* Kill Command (write) */
94 #define ALI1535_A_HIGH_BIT8 0x04 /* Bit 8 of 10-bit address in */
95 /* Alert-Response-Address */
96 /* (read) */
97
98 #define ALI1535_D_HI_MASK 0x03 /* Mask for isolating bits 9-8 */
99 /* of 10-bit address in I2C */
100 /* Read Command */
101
102 /* ALI1535 status register bits */
103 #define ALI1535_STS_IDLE 0x04
104 #define ALI1535_STS_BUSY 0x08 /* host busy */
105 #define ALI1535_STS_DONE 0x10 /* transaction complete */
106 #define ALI1535_STS_DEV 0x20 /* device error */
107 #define ALI1535_STS_BUSERR 0x40 /* bus error */
108 #define ALI1535_STS_FAIL 0x80 /* failed bus transaction */
109 #define ALI1535_STS_ERR 0xE0 /* all the bad error bits */
110
111 #define ALI1535_BLOCK_CLR 0x04 /* reset block data index */
112
113 /* ALI1535 device address register bits */
114 #define ALI1535_RD_ADDR 0x01 /* Read/Write Bit in Device */
115 /* Address field */
116 /* -> Write = 0 */
117 /* -> Read = 1 */
118 #define ALI1535_SMBIO_EN 0x04 /* SMB I/O Space enable */
119
120 static struct pci_driver ali1535_driver;
121 static unsigned long ali1535_smba;
122 static unsigned short ali1535_offset;
123
124 /* Detect whether a ALI1535 can be found, and initialize it, where necessary.
125 Note the differences between kernels with the old PCI BIOS interface and
126 newer kernels with the real PCI interface. In compat.h some things are
127 defined to make the transition easier. */
128 static int ali1535_setup(struct pci_dev *dev)
129 {
130 int retval;
131 unsigned char temp;
132
133 /* Check the following things:
134 - SMB I/O address is initialized
135 - Device is enabled
136 - We can use the addresses
137 */
138
139 retval = pci_enable_device(dev);
140 if (retval) {
141 dev_err(&dev->dev, "ALI1535_smb can't enable device\n");
142 goto exit;
143 }
144
145 /* Determine the address of the SMBus area */
146 pci_read_config_word(dev, SMBBA, &ali1535_offset);
147 dev_dbg(&dev->dev, "ALI1535_smb is at offset 0x%04x\n", ali1535_offset);
148 ali1535_offset &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
149 if (ali1535_offset == 0) {
150 dev_warn(&dev->dev,
151 "ALI1535_smb region uninitialized - upgrade BIOS?\n");
152 retval = -ENODEV;
153 goto exit;
154 }
155
156 if (pci_resource_flags(dev, 0) & IORESOURCE_IO)
157 ali1535_smba = pci_resource_start(dev, 0) + ali1535_offset;
158 else
159 ali1535_smba = ali1535_offset;
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%lx already in use!\n",
169 ali1535_smba);
170 retval = -EBUSY;
171 goto exit;
172 }
173
174 /* check if whole device is enabled */
175 pci_read_config_byte(dev, SMBCFG, &temp);
176 if ((temp & ALI1535_SMBIO_EN) == 0) {
177 dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
178 retval = -ENODEV;
179 goto exit_free;
180 }
181
182 /* Is SMB Host controller enabled? */
183 pci_read_config_byte(dev, SMBHSTCFG, &temp);
184 if ((temp & 1) == 0) {
185 dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
186 retval = -ENODEV;
187 goto exit_free;
188 }
189
190 /* set SMB clock to 74KHz as recommended in data sheet */
191 pci_write_config_byte(dev, SMBCLK, 0x20);
192
193 /*
194 The interrupt routing for SMB is set up in register 0x77 in the
195 1533 ISA Bridge device, NOT in the 7101 device.
196 Don't bother with finding the 1533 device and reading the register.
197 if ((....... & 0x0F) == 1)
198 dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
199 */
200 pci_read_config_byte(dev, SMBREV, &temp);
201 dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
202 dev_dbg(&dev->dev, "ALI1535_smba = 0x%lx\n", ali1535_smba);
203
204 return 0;
205
206 exit_free:
207 release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
208 exit:
209 return retval;
210 }
211
212 static int ali1535_transaction(struct i2c_adapter *adap)
213 {
214 int temp;
215 int result = 0;
216 int timeout = 0;
217
218 dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
219 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
220 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
221 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
222
223 /* get status */
224 temp = inb_p(SMBHSTSTS);
225
226 /* Make sure the SMBus host is ready to start transmitting */
227 /* Check the busy bit first */
228 if (temp & ALI1535_STS_BUSY) {
229 /* If the host controller is still busy, it may have timed out
230 * in the previous transaction, resulting in a "SMBus Timeout"
231 * printk. I've tried the following to reset a stuck busy bit.
232 * 1. Reset the controller with an KILL command. (this
233 * doesn't seem to clear the controller if an external
234 * device is hung)
235 * 2. Reset the controller and the other SMBus devices with a
236 * T_OUT command. (this clears the host busy bit if an
237 * external device is hung, but it comes back upon a new
238 * access to a device)
239 * 3. Disable and reenable the controller in SMBHSTCFG. Worst
240 * case, nothing seems to work except power reset.
241 */
242
243 /* Try resetting entire SMB bus, including other devices - This
244 * may not work either - it clears the BUSY bit but then the
245 * BUSY bit may come back on when you try and use the chip
246 * again. If that's the case you are stuck.
247 */
248 dev_info(&adap->dev,
249 "Resetting entire SMB Bus to clear busy condition (%02x)\n",
250 temp);
251 outb_p(ALI1535_T_OUT, SMBHSTTYP);
252 temp = inb_p(SMBHSTSTS);
253 }
254
255 /* now check the error bits and the busy bit */
256 if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
257 /* do a clear-on-write */
258 outb_p(0xFF, SMBHSTSTS);
259 temp = inb_p(SMBHSTSTS);
260 if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
261 /* This is probably going to be correctable only by a
262 * power reset as one of the bits now appears to be
263 * stuck */
264 /* This may be a bus or device with electrical problems. */
265 dev_err(&adap->dev,
266 "SMBus reset failed! (0x%02x) - controller or "
267 "device on bus is probably hung\n", temp);
268 return -EBUSY;
269 }
270 } else {
271 /* check and clear done bit */
272 if (temp & ALI1535_STS_DONE)
273 outb_p(temp, SMBHSTSTS);
274 }
275
276 /* start the transaction by writing anything to the start register */
277 outb_p(0xFF, SMBHSTPORT);
278
279 /* We will always wait for a fraction of a second! */
280 timeout = 0;
281 do {
282 usleep_range(1000, 2000);
283 temp = inb_p(SMBHSTSTS);
284 } while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
285 && (timeout++ < MAX_TIMEOUT));
286
287 /* If the SMBus is still busy, we give up */
288 if (timeout > MAX_TIMEOUT) {
289 result = -ETIMEDOUT;
290 dev_err(&adap->dev, "SMBus Timeout!\n");
291 }
292
293 if (temp & ALI1535_STS_FAIL) {
294 result = -EIO;
295 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
296 }
297
298 /* Unfortunately the ALI SMB controller maps "no response" and "bus
299 * collision" into a single bit. No response is the usual case so don't
300 * do a printk. This means that bus collisions go unreported.
301 */
302 if (temp & ALI1535_STS_BUSERR) {
303 result = -ENXIO;
304 dev_dbg(&adap->dev,
305 "Error: no response or bus collision ADD=%02x\n",
306 inb_p(SMBHSTADD));
307 }
308
309 /* haven't ever seen this */
310 if (temp & ALI1535_STS_DEV) {
311 result = -EIO;
312 dev_err(&adap->dev, "Error: device error\n");
313 }
314
315 /* check to see if the "command complete" indication is set */
316 if (!(temp & ALI1535_STS_DONE)) {
317 result = -ETIMEDOUT;
318 dev_err(&adap->dev, "Error: command never completed\n");
319 }
320
321 dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
322 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
323 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
324 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
325
326 /* take consequent actions for error conditions */
327 if (!(temp & ALI1535_STS_DONE)) {
328 /* issue "kill" to reset host controller */
329 outb_p(ALI1535_KILL, SMBHSTTYP);
330 outb_p(0xFF, SMBHSTSTS);
331 } else if (temp & ALI1535_STS_ERR) {
332 /* issue "timeout" to reset all devices on bus */
333 outb_p(ALI1535_T_OUT, SMBHSTTYP);
334 outb_p(0xFF, SMBHSTSTS);
335 }
336
337 return result;
338 }
339
340 /* Return negative errno on error. */
341 static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
342 unsigned short flags, char read_write, u8 command,
343 int size, union i2c_smbus_data *data)
344 {
345 int i, len;
346 int temp;
347 int timeout;
348 s32 result = 0;
349
350 /* make sure SMBus is idle */
351 temp = inb_p(SMBHSTSTS);
352 for (timeout = 0;
353 (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
354 timeout++) {
355 usleep_range(1000, 2000);
356 temp = inb_p(SMBHSTSTS);
357 }
358 if (timeout >= MAX_TIMEOUT)
359 dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
360
361 /* clear status register (clear-on-write) */
362 outb_p(0xFF, SMBHSTSTS);
363
364 switch (size) {
365 case I2C_SMBUS_QUICK:
366 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
367 SMBHSTADD);
368 size = ALI1535_QUICK;
369 outb_p(size, SMBHSTTYP); /* output command */
370 break;
371 case I2C_SMBUS_BYTE:
372 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
373 SMBHSTADD);
374 size = ALI1535_BYTE;
375 outb_p(size, SMBHSTTYP); /* output command */
376 if (read_write == I2C_SMBUS_WRITE)
377 outb_p(command, SMBHSTCMD);
378 break;
379 case I2C_SMBUS_BYTE_DATA:
380 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
381 SMBHSTADD);
382 size = ALI1535_BYTE_DATA;
383 outb_p(size, SMBHSTTYP); /* output command */
384 outb_p(command, SMBHSTCMD);
385 if (read_write == I2C_SMBUS_WRITE)
386 outb_p(data->byte, SMBHSTDAT0);
387 break;
388 case I2C_SMBUS_WORD_DATA:
389 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
390 SMBHSTADD);
391 size = ALI1535_WORD_DATA;
392 outb_p(size, SMBHSTTYP); /* output command */
393 outb_p(command, SMBHSTCMD);
394 if (read_write == I2C_SMBUS_WRITE) {
395 outb_p(data->word & 0xff, SMBHSTDAT0);
396 outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
397 }
398 break;
399 case I2C_SMBUS_BLOCK_DATA:
400 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
401 SMBHSTADD);
402 size = ALI1535_BLOCK_DATA;
403 outb_p(size, SMBHSTTYP); /* output command */
404 outb_p(command, SMBHSTCMD);
405 if (read_write == I2C_SMBUS_WRITE) {
406 len = data->block[0];
407 if (len < 0) {
408 len = 0;
409 data->block[0] = len;
410 }
411 if (len > 32) {
412 len = 32;
413 data->block[0] = len;
414 }
415 outb_p(len, SMBHSTDAT0);
416 /* Reset SMBBLKDAT */
417 outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
418 for (i = 1; i <= len; i++)
419 outb_p(data->block[i], SMBBLKDAT);
420 }
421 break;
422 default:
423 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
424 result = -EOPNOTSUPP;
425 goto EXIT;
426 }
427
428 result = ali1535_transaction(adap);
429 if (result)
430 goto EXIT;
431
432 if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
433 result = 0;
434 goto EXIT;
435 }
436
437 switch (size) {
438 case ALI1535_BYTE: /* Result put in SMBHSTDAT0 */
439 data->byte = inb_p(SMBHSTDAT0);
440 break;
441 case ALI1535_BYTE_DATA:
442 data->byte = inb_p(SMBHSTDAT0);
443 break;
444 case ALI1535_WORD_DATA:
445 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
446 break;
447 case ALI1535_BLOCK_DATA:
448 len = inb_p(SMBHSTDAT0);
449 if (len > 32)
450 len = 32;
451 data->block[0] = len;
452 /* Reset SMBBLKDAT */
453 outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
454 for (i = 1; i <= data->block[0]; i++) {
455 data->block[i] = inb_p(SMBBLKDAT);
456 dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
457 len, i, data->block[i]);
458 }
459 break;
460 }
461 EXIT:
462 return result;
463 }
464
465
466 static u32 ali1535_func(struct i2c_adapter *adapter)
467 {
468 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
469 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
470 I2C_FUNC_SMBUS_BLOCK_DATA;
471 }
472
473 static const struct i2c_algorithm smbus_algorithm = {
474 .smbus_xfer = ali1535_access,
475 .functionality = ali1535_func,
476 };
477
478 static struct i2c_adapter ali1535_adapter = {
479 .owner = THIS_MODULE,
480 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
481 .algo = &smbus_algorithm,
482 };
483
484 static const struct pci_device_id ali1535_ids[] = {
485 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
486 { },
487 };
488
489 MODULE_DEVICE_TABLE(pci, ali1535_ids);
490
491 static int ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
492 {
493 if (ali1535_setup(dev)) {
494 dev_warn(&dev->dev,
495 "ALI1535 not detected, module not inserted.\n");
496 return -ENODEV;
497 }
498
499 /* set up the sysfs linkage to our parent device */
500 ali1535_adapter.dev.parent = &dev->dev;
501
502 snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
503 "SMBus ALI1535 adapter at %04x", ali1535_offset);
504 return i2c_add_adapter(&ali1535_adapter);
505 }
506
507 static void ali1535_remove(struct pci_dev *dev)
508 {
509 i2c_del_adapter(&ali1535_adapter);
510 release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
511 }
512
513 static struct pci_driver ali1535_driver = {
514 .name = "ali1535_smbus",
515 .id_table = ali1535_ids,
516 .probe = ali1535_probe,
517 .remove = ali1535_remove,
518 };
519
520 module_pci_driver(ali1535_driver);
521
522 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
523 "Philip Edelbrock <phil@netroedge.com>, "
524 "Mark D. Studebaker <mdsxyz123@yahoo.com> "
525 "and Dan Eaton <dan.eaton@rocketlogix.com>");
526 MODULE_DESCRIPTION("ALI1535 SMBus driver");
527 MODULE_LICENSE("GPL");