xref: /openbmc/linux/drivers/i2c/busses/i2c-piix4.c (revision 87c2ce3b)
1 /*
2     piix4.c - Part of lm_sensors, Linux kernel modules for hardware
3               monitoring
4     Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl> and
5     Philip Edelbrock <phil@netroedge.com>
6 
7     This program is free software; you can redistribute it and/or modify
8     it under the terms of the GNU General Public License as published by
9     the Free Software Foundation; either version 2 of the License, or
10     (at your option) any later version.
11 
12     This program is distributed in the hope that it will be useful,
13     but WITHOUT ANY WARRANTY; without even the implied warranty of
14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15     GNU General Public License for more details.
16 
17     You should have received a copy of the GNU General Public License
18     along with this program; if not, write to the Free Software
19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21 
22 /*
23    Supports:
24 	Intel PIIX4, 440MX
25 	Serverworks OSB4, CSB5, CSB6
26 	SMSC Victory66
27 
28    Note: we assume there can only be one device, with one SMBus interface.
29 */
30 
31 #include <linux/module.h>
32 #include <linux/moduleparam.h>
33 #include <linux/pci.h>
34 #include <linux/kernel.h>
35 #include <linux/delay.h>
36 #include <linux/stddef.h>
37 #include <linux/sched.h>
38 #include <linux/ioport.h>
39 #include <linux/i2c.h>
40 #include <linux/init.h>
41 #include <linux/apm_bios.h>
42 #include <linux/dmi.h>
43 #include <asm/io.h>
44 
45 
46 struct sd {
47 	const unsigned short mfr;
48 	const unsigned short dev;
49 	const unsigned char fn;
50 	const char *name;
51 };
52 
53 /* PIIX4 SMBus address offsets */
54 #define SMBHSTSTS	(0 + piix4_smba)
55 #define SMBHSLVSTS	(1 + piix4_smba)
56 #define SMBHSTCNT	(2 + piix4_smba)
57 #define SMBHSTCMD	(3 + piix4_smba)
58 #define SMBHSTADD	(4 + piix4_smba)
59 #define SMBHSTDAT0	(5 + piix4_smba)
60 #define SMBHSTDAT1	(6 + piix4_smba)
61 #define SMBBLKDAT	(7 + piix4_smba)
62 #define SMBSLVCNT	(8 + piix4_smba)
63 #define SMBSHDWCMD	(9 + piix4_smba)
64 #define SMBSLVEVT	(0xA + piix4_smba)
65 #define SMBSLVDAT	(0xC + piix4_smba)
66 
67 /* count for request_region */
68 #define SMBIOSIZE	8
69 
70 /* PCI Address Constants */
71 #define SMBBA		0x090
72 #define SMBHSTCFG	0x0D2
73 #define SMBSLVC		0x0D3
74 #define SMBSHDW1	0x0D4
75 #define SMBSHDW2	0x0D5
76 #define SMBREV		0x0D6
77 
78 /* Other settings */
79 #define MAX_TIMEOUT	500
80 #define  ENABLE_INT9	0
81 
82 /* PIIX4 constants */
83 #define PIIX4_QUICK		0x00
84 #define PIIX4_BYTE		0x04
85 #define PIIX4_BYTE_DATA		0x08
86 #define PIIX4_WORD_DATA		0x0C
87 #define PIIX4_BLOCK_DATA	0x14
88 
89 /* insmod parameters */
90 
91 /* If force is set to anything different from 0, we forcibly enable the
92    PIIX4. DANGEROUS! */
93 static int force;
94 module_param (force, int, 0);
95 MODULE_PARM_DESC(force, "Forcibly enable the PIIX4. DANGEROUS!");
96 
97 /* If force_addr is set to anything different from 0, we forcibly enable
98    the PIIX4 at the given address. VERY DANGEROUS! */
99 static int force_addr;
100 module_param (force_addr, int, 0);
101 MODULE_PARM_DESC(force_addr,
102 		 "Forcibly enable the PIIX4 at the given address. "
103 		 "EXTREMELY DANGEROUS!");
104 
105 /* If fix_hstcfg is set to anything different from 0, we reset one of the
106    registers to be a valid value. */
107 static int fix_hstcfg;
108 module_param (fix_hstcfg, int, 0);
109 MODULE_PARM_DESC(fix_hstcfg,
110 		"Fix config register. Needed on some boards (Force CPCI735).");
111 
112 static int piix4_transaction(void);
113 
114 static unsigned short piix4_smba;
115 static struct pci_driver piix4_driver;
116 static struct i2c_adapter piix4_adapter;
117 
118 static struct dmi_system_id __devinitdata piix4_dmi_table[] = {
119 	{
120 		.ident = "IBM",
121 		.matches = { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
122 	},
123 	{ },
124 };
125 
126 static int __devinit piix4_setup(struct pci_dev *PIIX4_dev,
127 				const struct pci_device_id *id)
128 {
129 	unsigned char temp;
130 
131 	/* match up the function */
132 	if (PCI_FUNC(PIIX4_dev->devfn) != id->driver_data)
133 		return -ENODEV;
134 
135 	dev_info(&PIIX4_dev->dev, "Found %s device\n", pci_name(PIIX4_dev));
136 
137 	/* Don't access SMBus on IBM systems which get corrupted eeproms */
138 	if (dmi_check_system(piix4_dmi_table) &&
139 			PIIX4_dev->vendor == PCI_VENDOR_ID_INTEL) {
140 		dev_err(&PIIX4_dev->dev, "IBM Laptop detected; this module "
141 			"may corrupt your serial eeprom! Refusing to load "
142 			"module!\n");
143 		return -EPERM;
144 	}
145 
146 	/* Determine the address of the SMBus areas */
147 	if (force_addr) {
148 		piix4_smba = force_addr & 0xfff0;
149 		force = 0;
150 	} else {
151 		pci_read_config_word(PIIX4_dev, SMBBA, &piix4_smba);
152 		piix4_smba &= 0xfff0;
153 		if(piix4_smba == 0) {
154 			dev_err(&PIIX4_dev->dev, "SMB base address "
155 				"uninitialized - upgrade BIOS or use "
156 				"force_addr=0xaddr\n");
157 			return -ENODEV;
158 		}
159 	}
160 
161 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
162 		dev_err(&PIIX4_dev->dev, "SMB region 0x%x already in use!\n",
163 			piix4_smba);
164 		return -ENODEV;
165 	}
166 
167 	pci_read_config_byte(PIIX4_dev, SMBHSTCFG, &temp);
168 
169 	/* Some BIOS will set up the chipset incorrectly and leave a register
170 	   in an undefined state (causing I2C to act very strangely). */
171 	if (temp & 0x02) {
172 		if (fix_hstcfg) {
173 			dev_info(&PIIX4_dev->dev, "Working around buggy BIOS "
174 					"(I2C)\n");
175 			temp &= 0xfd;
176 			pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp);
177 		} else {
178 			dev_info(&PIIX4_dev->dev, "Unusual config register "
179 					"value\n");
180 			dev_info(&PIIX4_dev->dev, "Try using fix_hstcfg=1 if "
181 					"you experience problems\n");
182 		}
183 	}
184 
185 	/* If force_addr is set, we program the new address here. Just to make
186 	   sure, we disable the PIIX4 first. */
187 	if (force_addr) {
188 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp & 0xfe);
189 		pci_write_config_word(PIIX4_dev, SMBBA, piix4_smba);
190 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp | 0x01);
191 		dev_info(&PIIX4_dev->dev, "WARNING: SMBus interface set to "
192 			"new address %04x!\n", piix4_smba);
193 	} else if ((temp & 1) == 0) {
194 		if (force) {
195 			/* This should never need to be done, but has been
196 			 * noted that many Dell machines have the SMBus
197 			 * interface on the PIIX4 disabled!? NOTE: This assumes
198 			 * I/O space and other allocations WERE done by the
199 			 * Bios!  Don't complain if your hardware does weird
200 			 * things after enabling this. :') Check for Bios
201 			 * updates before resorting to this.
202 			 */
203 			pci_write_config_byte(PIIX4_dev, SMBHSTCFG,
204 					      temp | 1);
205 			dev_printk(KERN_NOTICE, &PIIX4_dev->dev,
206 				"WARNING: SMBus interface has been "
207 				"FORCEFULLY ENABLED!\n");
208 		} else {
209 			dev_err(&PIIX4_dev->dev,
210 				"Host SMBus controller not enabled!\n");
211 			release_region(piix4_smba, SMBIOSIZE);
212 			piix4_smba = 0;
213 			return -ENODEV;
214 		}
215 	}
216 
217 	if ((temp & 0x0E) == 8)
218 		dev_dbg(&PIIX4_dev->dev, "Using Interrupt 9 for SMBus.\n");
219 	else if ((temp & 0x0E) == 0)
220 		dev_dbg(&PIIX4_dev->dev, "Using Interrupt SMI# for SMBus.\n");
221 	else
222 		dev_err(&PIIX4_dev->dev, "Illegal Interrupt configuration "
223 			"(or code out of date)!\n");
224 
225 	pci_read_config_byte(PIIX4_dev, SMBREV, &temp);
226 	dev_dbg(&PIIX4_dev->dev, "SMBREV = 0x%X\n", temp);
227 	dev_dbg(&PIIX4_dev->dev, "SMBA = 0x%X\n", piix4_smba);
228 
229 	return 0;
230 }
231 
232 /* Another internally used function */
233 static int piix4_transaction(void)
234 {
235 	int temp;
236 	int result = 0;
237 	int timeout = 0;
238 
239 	dev_dbg(&piix4_adapter.dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
240 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
241 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
242 		inb_p(SMBHSTDAT1));
243 
244 	/* Make sure the SMBus host is ready to start transmitting */
245 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
246 		dev_dbg(&piix4_adapter.dev, "SMBus busy (%02x). "
247 			"Resetting...\n", temp);
248 		outb_p(temp, SMBHSTSTS);
249 		if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
250 			dev_err(&piix4_adapter.dev, "Failed! (%02x)\n", temp);
251 			return -1;
252 		} else {
253 			dev_dbg(&piix4_adapter.dev, "Successfull!\n");
254 		}
255 	}
256 
257 	/* start the transaction by setting bit 6 */
258 	outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);
259 
260 	/* We will always wait for a fraction of a second! (See PIIX4 docs errata) */
261 	do {
262 		msleep(1);
263 		temp = inb_p(SMBHSTSTS);
264 	} while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
265 
266 	/* If the SMBus is still busy, we give up */
267 	if (timeout >= MAX_TIMEOUT) {
268 		dev_err(&piix4_adapter.dev, "SMBus Timeout!\n");
269 		result = -1;
270 	}
271 
272 	if (temp & 0x10) {
273 		result = -1;
274 		dev_err(&piix4_adapter.dev, "Error: Failed bus transaction\n");
275 	}
276 
277 	if (temp & 0x08) {
278 		result = -1;
279 		dev_dbg(&piix4_adapter.dev, "Bus collision! SMBus may be "
280 			"locked until next hard reset. (sorry!)\n");
281 		/* Clock stops and slave is stuck in mid-transmission */
282 	}
283 
284 	if (temp & 0x04) {
285 		result = -1;
286 		dev_dbg(&piix4_adapter.dev, "Error: no response!\n");
287 	}
288 
289 	if (inb_p(SMBHSTSTS) != 0x00)
290 		outb_p(inb(SMBHSTSTS), SMBHSTSTS);
291 
292 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
293 		dev_err(&piix4_adapter.dev, "Failed reset at end of "
294 			"transaction (%02x)\n", temp);
295 	}
296 	dev_dbg(&piix4_adapter.dev, "Transaction (post): CNT=%02x, CMD=%02x, "
297 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
298 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
299 		inb_p(SMBHSTDAT1));
300 	return result;
301 }
302 
303 /* Return -1 on error. */
304 static s32 piix4_access(struct i2c_adapter * adap, u16 addr,
305 		 unsigned short flags, char read_write,
306 		 u8 command, int size, union i2c_smbus_data * data)
307 {
308 	int i, len;
309 
310 	switch (size) {
311 	case I2C_SMBUS_PROC_CALL:
312 		dev_err(&adap->dev, "I2C_SMBUS_PROC_CALL not supported!\n");
313 		return -1;
314 	case I2C_SMBUS_QUICK:
315 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
316 		       SMBHSTADD);
317 		size = PIIX4_QUICK;
318 		break;
319 	case I2C_SMBUS_BYTE:
320 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
321 		       SMBHSTADD);
322 		if (read_write == I2C_SMBUS_WRITE)
323 			outb_p(command, SMBHSTCMD);
324 		size = PIIX4_BYTE;
325 		break;
326 	case I2C_SMBUS_BYTE_DATA:
327 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
328 		       SMBHSTADD);
329 		outb_p(command, SMBHSTCMD);
330 		if (read_write == I2C_SMBUS_WRITE)
331 			outb_p(data->byte, SMBHSTDAT0);
332 		size = PIIX4_BYTE_DATA;
333 		break;
334 	case I2C_SMBUS_WORD_DATA:
335 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
336 		       SMBHSTADD);
337 		outb_p(command, SMBHSTCMD);
338 		if (read_write == I2C_SMBUS_WRITE) {
339 			outb_p(data->word & 0xff, SMBHSTDAT0);
340 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
341 		}
342 		size = PIIX4_WORD_DATA;
343 		break;
344 	case I2C_SMBUS_BLOCK_DATA:
345 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
346 		       SMBHSTADD);
347 		outb_p(command, SMBHSTCMD);
348 		if (read_write == I2C_SMBUS_WRITE) {
349 			len = data->block[0];
350 			if (len < 0)
351 				len = 0;
352 			if (len > 32)
353 				len = 32;
354 			outb_p(len, SMBHSTDAT0);
355 			i = inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
356 			for (i = 1; i <= len; i++)
357 				outb_p(data->block[i], SMBBLKDAT);
358 		}
359 		size = PIIX4_BLOCK_DATA;
360 		break;
361 	}
362 
363 	outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);
364 
365 	if (piix4_transaction())	/* Error in transaction */
366 		return -1;
367 
368 	if ((read_write == I2C_SMBUS_WRITE) || (size == PIIX4_QUICK))
369 		return 0;
370 
371 
372 	switch (size) {
373 	case PIIX4_BYTE:	/* Where is the result put? I assume here it is in
374 				   SMBHSTDAT0 but it might just as well be in the
375 				   SMBHSTCMD. No clue in the docs */
376 
377 		data->byte = inb_p(SMBHSTDAT0);
378 		break;
379 	case PIIX4_BYTE_DATA:
380 		data->byte = inb_p(SMBHSTDAT0);
381 		break;
382 	case PIIX4_WORD_DATA:
383 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
384 		break;
385 	case PIIX4_BLOCK_DATA:
386 		data->block[0] = inb_p(SMBHSTDAT0);
387 		i = inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
388 		for (i = 1; i <= data->block[0]; i++)
389 			data->block[i] = inb_p(SMBBLKDAT);
390 		break;
391 	}
392 	return 0;
393 }
394 
395 static u32 piix4_func(struct i2c_adapter *adapter)
396 {
397 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
398 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
399 	    I2C_FUNC_SMBUS_BLOCK_DATA;
400 }
401 
402 static struct i2c_algorithm smbus_algorithm = {
403 	.smbus_xfer	= piix4_access,
404 	.functionality	= piix4_func,
405 };
406 
407 static struct i2c_adapter piix4_adapter = {
408 	.owner		= THIS_MODULE,
409 	.class		= I2C_CLASS_HWMON,
410 	.algo		= &smbus_algorithm,
411 };
412 
413 static struct pci_device_id piix4_ids[] = {
414 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3),
415 	  .driver_data = 3 },
416 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_OSB4),
417 	  .driver_data = 0 },
418 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_CSB5),
419 	  .driver_data = 0 },
420 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_CSB6),
421 	  .driver_data = 0 },
422 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3),
423 	  .driver_data = 3 },
424 	{ PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_SLC90E66_3),
425 	  .driver_data = 0 },
426 	{ 0, }
427 };
428 
429 MODULE_DEVICE_TABLE (pci, piix4_ids);
430 
431 static int __devinit piix4_probe(struct pci_dev *dev,
432 				const struct pci_device_id *id)
433 {
434 	int retval;
435 
436 	retval = piix4_setup(dev, id);
437 	if (retval)
438 		return retval;
439 
440 	/* set up the driverfs linkage to our parent device */
441 	piix4_adapter.dev.parent = &dev->dev;
442 
443 	snprintf(piix4_adapter.name, I2C_NAME_SIZE,
444 		"SMBus PIIX4 adapter at %04x", piix4_smba);
445 
446 	if ((retval = i2c_add_adapter(&piix4_adapter))) {
447 		dev_err(&dev->dev, "Couldn't register adapter!\n");
448 		release_region(piix4_smba, SMBIOSIZE);
449 		piix4_smba = 0;
450 	}
451 
452 	return retval;
453 }
454 
455 static void __devexit piix4_remove(struct pci_dev *dev)
456 {
457 	if (piix4_smba) {
458 		i2c_del_adapter(&piix4_adapter);
459 		release_region(piix4_smba, SMBIOSIZE);
460 		piix4_smba = 0;
461 	}
462 }
463 
464 static struct pci_driver piix4_driver = {
465 	.name		= "piix4_smbus",
466 	.id_table	= piix4_ids,
467 	.probe		= piix4_probe,
468 	.remove		= __devexit_p(piix4_remove),
469 };
470 
471 static int __init i2c_piix4_init(void)
472 {
473 	return pci_register_driver(&piix4_driver);
474 }
475 
476 static void __exit i2c_piix4_exit(void)
477 {
478 	pci_unregister_driver(&piix4_driver);
479 }
480 
481 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
482 		"Philip Edelbrock <phil@netroedge.com>");
483 MODULE_DESCRIPTION("PIIX4 SMBus driver");
484 MODULE_LICENSE("GPL");
485 
486 module_init(i2c_piix4_init);
487 module_exit(i2c_piix4_exit);
488