xref: /linux/drivers/i2c/busses/i2c-ali15x3.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2     ali15x3.c - Part of lm_sensors, Linux kernel modules for hardware
3               monitoring
4     Copyright (c) 1999  Frodo Looijaard <frodol@dds.nl> and
5     Philip Edelbrock <phil@netroedge.com> and
6     Mark D. Studebaker <mdsxyz123@yahoo.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) M1541 and M1543C South Bridges.
26 
27     The M1543C is a South bridge for desktop systems.
28     The M1533 is a South bridge for portable systems.
29     They are part of the following ALI chipsets:
30        "Aladdin Pro 2": Includes the M1621 Slot 1 North bridge
31        with AGP and 100MHz CPU Front Side bus
32        "Aladdin V": Includes the M1541 Socket 7 North bridge
33        with AGP and 100MHz CPU Front Side bus
34        "Aladdin IV": Includes the M1541 Socket 7 North bridge
35        with host bus up to 83.3 MHz.
36     For an overview of these chips see http://www.acerlabs.com
37 
38     The M1533/M1543C devices appear as FOUR separate devices
39     on the PCI bus. An output of lspci will show something similar
40     to the following:
41 
42 	00:02.0 USB Controller: Acer Laboratories Inc. M5237
43 	00:03.0 Bridge: Acer Laboratories Inc. M7101
44 	00:07.0 ISA bridge: Acer Laboratories Inc. M1533
45 	00:0f.0 IDE interface: Acer Laboratories Inc. M5229
46 
47     The SMB controller is part of the 7101 device, which is an
48     ACPI-compliant Power Management Unit (PMU).
49 
50     The whole 7101 device has to be enabled for the SMB to work.
51     You can't just enable the SMB alone.
52     The SMB and the ACPI have separate I/O spaces.
53     We make sure that the SMB is enabled. We leave the ACPI alone.
54 
55     This driver controls the SMB Host only.
56     The SMB Slave controller on the M15X3 is not enabled.
57 
58     This driver does not use interrupts.
59 */
60 
61 /* Note: we assume there can only be one ALI15X3, with one SMBus interface */
62 
63 #include <linux/module.h>
64 #include <linux/pci.h>
65 #include <linux/kernel.h>
66 #include <linux/stddef.h>
67 #include <linux/sched.h>
68 #include <linux/ioport.h>
69 #include <linux/delay.h>
70 #include <linux/i2c.h>
71 #include <linux/init.h>
72 #include <asm/io.h>
73 
74 /* ALI15X3 SMBus address offsets */
75 #define SMBHSTSTS	(0 + ali15x3_smba)
76 #define SMBHSTCNT	(1 + ali15x3_smba)
77 #define SMBHSTSTART	(2 + ali15x3_smba)
78 #define SMBHSTCMD	(7 + ali15x3_smba)
79 #define SMBHSTADD	(3 + ali15x3_smba)
80 #define SMBHSTDAT0	(4 + ali15x3_smba)
81 #define SMBHSTDAT1	(5 + ali15x3_smba)
82 #define SMBBLKDAT	(6 + ali15x3_smba)
83 
84 /* PCI Address Constants */
85 #define SMBCOM		0x004
86 #define SMBBA		0x014
87 #define SMBATPC		0x05B	/* used to unlock xxxBA registers */
88 #define SMBHSTCFG	0x0E0
89 #define SMBSLVC		0x0E1
90 #define SMBCLK		0x0E2
91 #define SMBREV		0x008
92 
93 /* Other settings */
94 #define MAX_TIMEOUT		200	/* times 1/100 sec */
95 #define ALI15X3_SMB_IOSIZE	32
96 
97 /* this is what the Award 1004 BIOS sets them to on a ASUS P5A MB.
98    We don't use these here. If the bases aren't set to some value we
99    tell user to upgrade BIOS and we fail.
100 */
101 #define ALI15X3_SMB_DEFAULTBASE	0xE800
102 
103 /* ALI15X3 address lock bits */
104 #define ALI15X3_LOCK		0x06
105 
106 /* ALI15X3 command constants */
107 #define ALI15X3_ABORT		0x02
108 #define ALI15X3_T_OUT		0x04
109 #define ALI15X3_QUICK		0x00
110 #define ALI15X3_BYTE		0x10
111 #define ALI15X3_BYTE_DATA	0x20
112 #define ALI15X3_WORD_DATA	0x30
113 #define ALI15X3_BLOCK_DATA	0x40
114 #define ALI15X3_BLOCK_CLR	0x80
115 
116 /* ALI15X3 status register bits */
117 #define ALI15X3_STS_IDLE	0x04
118 #define ALI15X3_STS_BUSY	0x08
119 #define ALI15X3_STS_DONE	0x10
120 #define ALI15X3_STS_DEV		0x20	/* device error */
121 #define ALI15X3_STS_COLL	0x40	/* collision or no response */
122 #define ALI15X3_STS_TERM	0x80	/* terminated by abort */
123 #define ALI15X3_STS_ERR		0xE0	/* all the bad error bits */
124 
125 
126 /* If force_addr is set to anything different from 0, we forcibly enable
127    the device at the given address. */
128 static u16 force_addr;
129 module_param(force_addr, ushort, 0);
130 MODULE_PARM_DESC(force_addr,
131 		 "Initialize the base address of the i2c controller");
132 
133 static struct pci_driver ali15x3_driver;
134 static unsigned short ali15x3_smba;
135 
136 static int ali15x3_setup(struct pci_dev *ALI15X3_dev)
137 {
138 	u16 a;
139 	unsigned char temp;
140 
141 	/* Check the following things:
142 		- SMB I/O address is initialized
143 		- Device is enabled
144 		- We can use the addresses
145 	*/
146 
147 	/* Unlock the register.
148 	   The data sheet says that the address registers are read-only
149 	   if the lock bits are 1, but in fact the address registers
150 	   are zero unless you clear the lock bits.
151 	*/
152 	pci_read_config_byte(ALI15X3_dev, SMBATPC, &temp);
153 	if (temp & ALI15X3_LOCK) {
154 		temp &= ~ALI15X3_LOCK;
155 		pci_write_config_byte(ALI15X3_dev, SMBATPC, temp);
156 	}
157 
158 	/* Determine the address of the SMBus area */
159 	pci_read_config_word(ALI15X3_dev, SMBBA, &ali15x3_smba);
160 	ali15x3_smba &= (0xffff & ~(ALI15X3_SMB_IOSIZE - 1));
161 	if (ali15x3_smba == 0 && force_addr == 0) {
162 		dev_err(&ALI15X3_dev->dev, "ALI15X3_smb region uninitialized "
163 			"- upgrade BIOS or use force_addr=0xaddr\n");
164 		return -ENODEV;
165 	}
166 
167 	if(force_addr)
168 		ali15x3_smba = force_addr & ~(ALI15X3_SMB_IOSIZE - 1);
169 
170 	if (!request_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
171 			    ali15x3_driver.name)) {
172 		dev_err(&ALI15X3_dev->dev,
173 			"ALI15X3_smb region 0x%x already in use!\n",
174 			ali15x3_smba);
175 		return -ENODEV;
176 	}
177 
178 	if(force_addr) {
179 		dev_info(&ALI15X3_dev->dev, "forcing ISA address 0x%04X\n",
180 			ali15x3_smba);
181 		if (PCIBIOS_SUCCESSFUL != pci_write_config_word(ALI15X3_dev,
182 								SMBBA,
183 								ali15x3_smba))
184 			goto error;
185 		if (PCIBIOS_SUCCESSFUL != pci_read_config_word(ALI15X3_dev,
186 								SMBBA, &a))
187 			goto error;
188 		if ((a & ~(ALI15X3_SMB_IOSIZE - 1)) != ali15x3_smba) {
189 			/* make sure it works */
190 			dev_err(&ALI15X3_dev->dev,
191 				"force address failed - not supported?\n");
192 			goto error;
193 		}
194 	}
195 	/* check if whole device is enabled */
196 	pci_read_config_byte(ALI15X3_dev, SMBCOM, &temp);
197 	if ((temp & 1) == 0) {
198 		dev_info(&ALI15X3_dev->dev, "enabling SMBus device\n");
199 		pci_write_config_byte(ALI15X3_dev, SMBCOM, temp | 0x01);
200 	}
201 
202 	/* Is SMB Host controller enabled? */
203 	pci_read_config_byte(ALI15X3_dev, SMBHSTCFG, &temp);
204 	if ((temp & 1) == 0) {
205 		dev_info(&ALI15X3_dev->dev, "enabling SMBus controller\n");
206 		pci_write_config_byte(ALI15X3_dev, SMBHSTCFG, temp | 0x01);
207 	}
208 
209 	/* set SMB clock to 74KHz as recommended in data sheet */
210 	pci_write_config_byte(ALI15X3_dev, SMBCLK, 0x20);
211 
212 	/*
213 	  The interrupt routing for SMB is set up in register 0x77 in the
214 	  1533 ISA Bridge device, NOT in the 7101 device.
215 	  Don't bother with finding the 1533 device and reading the register.
216 	if ((....... & 0x0F) == 1)
217 		dev_dbg(&ALI15X3_dev->dev, "ALI15X3 using Interrupt 9 for SMBus.\n");
218 	*/
219 	pci_read_config_byte(ALI15X3_dev, SMBREV, &temp);
220 	dev_dbg(&ALI15X3_dev->dev, "SMBREV = 0x%X\n", temp);
221 	dev_dbg(&ALI15X3_dev->dev, "iALI15X3_smba = 0x%X\n", ali15x3_smba);
222 
223 	return 0;
224 error:
225 	release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
226 	return -ENODEV;
227 }
228 
229 /* Another internally used function */
230 static int ali15x3_transaction(struct i2c_adapter *adap)
231 {
232 	int temp;
233 	int result = 0;
234 	int timeout = 0;
235 
236 	dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, CNT=%02x, CMD=%02x, "
237 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
238 		inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
239 		inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
240 
241 	/* get status */
242 	temp = inb_p(SMBHSTSTS);
243 
244 	/* Make sure the SMBus host is ready to start transmitting */
245 	/* Check the busy bit first */
246 	if (temp & ALI15X3_STS_BUSY) {
247 	/*
248 	   If the host controller is still busy, it may have timed out in the
249 	   previous transaction, resulting in a "SMBus Timeout" Dev.
250 	   I've tried the following to reset a stuck busy bit.
251 		1. Reset the controller with an ABORT command.
252 		   (this doesn't seem to clear the controller if an external
253 		   device is hung)
254 		2. Reset the controller and the other SMBus devices with a
255 		   T_OUT command.  (this clears the host busy bit if an
256 		   external device is hung, but it comes back upon a new access
257 		   to a device)
258 		3. Disable and reenable the controller in SMBHSTCFG
259 	   Worst case, nothing seems to work except power reset.
260 	*/
261 	/* Abort - reset the host controller */
262 	/*
263 	   Try resetting entire SMB bus, including other devices -
264 	   This may not work either - it clears the BUSY bit but
265 	   then the BUSY bit may come back on when you try and use the chip again.
266 	   If that's the case you are stuck.
267 	*/
268 		dev_info(&adap->dev, "Resetting entire SMB Bus to "
269 			"clear busy condition (%02x)\n", temp);
270 		outb_p(ALI15X3_T_OUT, SMBHSTCNT);
271 		temp = inb_p(SMBHSTSTS);
272 	}
273 
274 	/* now check the error bits and the busy bit */
275 	if (temp & (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
276 		/* do a clear-on-write */
277 		outb_p(0xFF, SMBHSTSTS);
278 		if ((temp = inb_p(SMBHSTSTS)) &
279 		    (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
280 			/* this is probably going to be correctable only by a power reset
281 			   as one of the bits now appears to be stuck */
282 			/* This may be a bus or device with electrical problems. */
283 			dev_err(&adap->dev, "SMBus reset failed! (0x%02x) - "
284 				"controller or device on bus is probably hung\n",
285 				temp);
286 			return -1;
287 		}
288 	} else {
289 		/* check and clear done bit */
290 		if (temp & ALI15X3_STS_DONE) {
291 			outb_p(temp, SMBHSTSTS);
292 		}
293 	}
294 
295 	/* start the transaction by writing anything to the start register */
296 	outb_p(0xFF, SMBHSTSTART);
297 
298 	/* We will always wait for a fraction of a second! */
299 	timeout = 0;
300 	do {
301 		msleep(1);
302 		temp = inb_p(SMBHSTSTS);
303 	} while ((!(temp & (ALI15X3_STS_ERR | ALI15X3_STS_DONE)))
304 		 && (timeout++ < MAX_TIMEOUT));
305 
306 	/* If the SMBus is still busy, we give up */
307 	if (timeout >= MAX_TIMEOUT) {
308 		result = -1;
309 		dev_err(&adap->dev, "SMBus Timeout!\n");
310 	}
311 
312 	if (temp & ALI15X3_STS_TERM) {
313 		result = -1;
314 		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
315 	}
316 
317 	/*
318 	  Unfortunately the ALI SMB controller maps "no response" and "bus
319 	  collision" into a single bit. No reponse is the usual case so don't
320 	  do a printk.
321 	  This means that bus collisions go unreported.
322 	*/
323 	if (temp & ALI15X3_STS_COLL) {
324 		result = -1;
325 		dev_dbg(&adap->dev,
326 			"Error: no response or bus collision ADD=%02x\n",
327 			inb_p(SMBHSTADD));
328 	}
329 
330 	/* haven't ever seen this */
331 	if (temp & ALI15X3_STS_DEV) {
332 		result = -1;
333 		dev_err(&adap->dev, "Error: device error\n");
334 	}
335 	dev_dbg(&adap->dev, "Transaction (post): STS=%02x, CNT=%02x, CMD=%02x, "
336 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
337 		inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
338 		inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
339 	return result;
340 }
341 
342 /* Return -1 on error. */
343 static s32 ali15x3_access(struct i2c_adapter * adap, u16 addr,
344 		   unsigned short flags, char read_write, u8 command,
345 		   int size, union i2c_smbus_data * data)
346 {
347 	int i, len;
348 	int temp;
349 	int timeout;
350 
351 	/* clear all the bits (clear-on-write) */
352 	outb_p(0xFF, SMBHSTSTS);
353 	/* make sure SMBus is idle */
354 	temp = inb_p(SMBHSTSTS);
355 	for (timeout = 0;
356 	     (timeout < MAX_TIMEOUT) && !(temp & ALI15X3_STS_IDLE);
357 	     timeout++) {
358 		msleep(1);
359 		temp = inb_p(SMBHSTSTS);
360 	}
361 	if (timeout >= MAX_TIMEOUT) {
362 		dev_err(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
363 	}
364 
365 	switch (size) {
366 	case I2C_SMBUS_PROC_CALL:
367 		dev_err(&adap->dev, "I2C_SMBUS_PROC_CALL not supported!\n");
368 		return -1;
369 	case I2C_SMBUS_QUICK:
370 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
371 		       SMBHSTADD);
372 		size = ALI15X3_QUICK;
373 		break;
374 	case I2C_SMBUS_BYTE:
375 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
376 		       SMBHSTADD);
377 		if (read_write == I2C_SMBUS_WRITE)
378 			outb_p(command, SMBHSTCMD);
379 		size = ALI15X3_BYTE;
380 		break;
381 	case I2C_SMBUS_BYTE_DATA:
382 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
383 		       SMBHSTADD);
384 		outb_p(command, SMBHSTCMD);
385 		if (read_write == I2C_SMBUS_WRITE)
386 			outb_p(data->byte, SMBHSTDAT0);
387 		size = ALI15X3_BYTE_DATA;
388 		break;
389 	case I2C_SMBUS_WORD_DATA:
390 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
391 		       SMBHSTADD);
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 		size = ALI15X3_WORD_DATA;
398 		break;
399 	case I2C_SMBUS_BLOCK_DATA:
400 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
401 		       SMBHSTADD);
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(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
416 			for (i = 1; i <= len; i++)
417 				outb_p(data->block[i], SMBBLKDAT);
418 		}
419 		size = ALI15X3_BLOCK_DATA;
420 		break;
421 	}
422 
423 	outb_p(size, SMBHSTCNT);	/* output command */
424 
425 	if (ali15x3_transaction(adap))	/* Error in transaction */
426 		return -1;
427 
428 	if ((read_write == I2C_SMBUS_WRITE) || (size == ALI15X3_QUICK))
429 		return 0;
430 
431 
432 	switch (size) {
433 	case ALI15X3_BYTE:	/* Result put in SMBHSTDAT0 */
434 		data->byte = inb_p(SMBHSTDAT0);
435 		break;
436 	case ALI15X3_BYTE_DATA:
437 		data->byte = inb_p(SMBHSTDAT0);
438 		break;
439 	case ALI15X3_WORD_DATA:
440 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
441 		break;
442 	case ALI15X3_BLOCK_DATA:
443 		len = inb_p(SMBHSTDAT0);
444 		if (len > 32)
445 			len = 32;
446 		data->block[0] = len;
447 		/* Reset SMBBLKDAT */
448 		outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
449 		for (i = 1; i <= data->block[0]; i++) {
450 			data->block[i] = inb_p(SMBBLKDAT);
451 			dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
452 				len, i, data->block[i]);
453 		}
454 		break;
455 	}
456 	return 0;
457 }
458 
459 static u32 ali15x3_func(struct i2c_adapter *adapter)
460 {
461 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
462 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
463 	    I2C_FUNC_SMBUS_BLOCK_DATA;
464 }
465 
466 static struct i2c_algorithm smbus_algorithm = {
467 	.smbus_xfer	= ali15x3_access,
468 	.functionality	= ali15x3_func,
469 };
470 
471 static struct i2c_adapter ali15x3_adapter = {
472 	.owner		= THIS_MODULE,
473 	.class          = I2C_CLASS_HWMON,
474 	.algo		= &smbus_algorithm,
475 };
476 
477 static struct pci_device_id ali15x3_ids[] = {
478 	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
479 	{ 0, }
480 };
481 
482 MODULE_DEVICE_TABLE (pci, ali15x3_ids);
483 
484 static int __devinit ali15x3_probe(struct pci_dev *dev, const struct pci_device_id *id)
485 {
486 	if (ali15x3_setup(dev)) {
487 		dev_err(&dev->dev,
488 			"ALI15X3 not detected, module not inserted.\n");
489 		return -ENODEV;
490 	}
491 
492 	/* set up the driverfs linkage to our parent device */
493 	ali15x3_adapter.dev.parent = &dev->dev;
494 
495 	snprintf(ali15x3_adapter.name, I2C_NAME_SIZE,
496 		"SMBus ALI15X3 adapter at %04x", ali15x3_smba);
497 	return i2c_add_adapter(&ali15x3_adapter);
498 }
499 
500 static void __devexit ali15x3_remove(struct pci_dev *dev)
501 {
502 	i2c_del_adapter(&ali15x3_adapter);
503 	release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
504 }
505 
506 static struct pci_driver ali15x3_driver = {
507 	.name		= "ali15x3_smbus",
508 	.id_table	= ali15x3_ids,
509 	.probe		= ali15x3_probe,
510 	.remove		= __devexit_p(ali15x3_remove),
511 };
512 
513 static int __init i2c_ali15x3_init(void)
514 {
515 	return pci_register_driver(&ali15x3_driver);
516 }
517 
518 static void __exit i2c_ali15x3_exit(void)
519 {
520 	pci_unregister_driver(&ali15x3_driver);
521 }
522 
523 MODULE_AUTHOR ("Frodo Looijaard <frodol@dds.nl>, "
524 		"Philip Edelbrock <phil@netroedge.com>, "
525 		"and Mark D. Studebaker <mdsxyz123@yahoo.com>");
526 MODULE_DESCRIPTION("ALI15X3 SMBus driver");
527 MODULE_LICENSE("GPL");
528 
529 module_init(i2c_ali15x3_init);
530 module_exit(i2c_ali15x3_exit);
531