xref: /openbmc/linux/drivers/i2c/busses/i2c-piix4.c (revision 64c70b1c)
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, HT-1000
26 	ATI IXP200, IXP300, IXP400, SB600
27 	SMSC Victory66
28 
29    Note: we assume there can only be one device, with one SMBus interface.
30 */
31 
32 #include <linux/module.h>
33 #include <linux/moduleparam.h>
34 #include <linux/pci.h>
35 #include <linux/kernel.h>
36 #include <linux/delay.h>
37 #include <linux/stddef.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 static int piix4_transaction(void);
106 
107 static unsigned short piix4_smba;
108 static struct pci_driver piix4_driver;
109 static struct i2c_adapter piix4_adapter;
110 
111 static struct dmi_system_id __devinitdata piix4_dmi_table[] = {
112 	{
113 		.ident = "IBM",
114 		.matches = { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
115 	},
116 	{ },
117 };
118 
119 static int __devinit piix4_setup(struct pci_dev *PIIX4_dev,
120 				const struct pci_device_id *id)
121 {
122 	unsigned char temp;
123 
124 	/* match up the function */
125 	if (PCI_FUNC(PIIX4_dev->devfn) != id->driver_data)
126 		return -ENODEV;
127 
128 	dev_info(&PIIX4_dev->dev, "Found %s device\n", pci_name(PIIX4_dev));
129 
130 	/* Don't access SMBus on IBM systems which get corrupted eeproms */
131 	if (dmi_check_system(piix4_dmi_table) &&
132 			PIIX4_dev->vendor == PCI_VENDOR_ID_INTEL) {
133 		dev_err(&PIIX4_dev->dev, "IBM system detected; this module "
134 			"may corrupt your serial eeprom! Refusing to load "
135 			"module!\n");
136 		return -EPERM;
137 	}
138 
139 	/* Determine the address of the SMBus areas */
140 	if (force_addr) {
141 		piix4_smba = force_addr & 0xfff0;
142 		force = 0;
143 	} else {
144 		pci_read_config_word(PIIX4_dev, SMBBA, &piix4_smba);
145 		piix4_smba &= 0xfff0;
146 		if(piix4_smba == 0) {
147 			dev_err(&PIIX4_dev->dev, "SMB base address "
148 				"uninitialized - upgrade BIOS or use "
149 				"force_addr=0xaddr\n");
150 			return -ENODEV;
151 		}
152 	}
153 
154 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
155 		dev_err(&PIIX4_dev->dev, "SMB region 0x%x already in use!\n",
156 			piix4_smba);
157 		return -ENODEV;
158 	}
159 
160 	pci_read_config_byte(PIIX4_dev, SMBHSTCFG, &temp);
161 
162 	/* If force_addr is set, we program the new address here. Just to make
163 	   sure, we disable the PIIX4 first. */
164 	if (force_addr) {
165 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp & 0xfe);
166 		pci_write_config_word(PIIX4_dev, SMBBA, piix4_smba);
167 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp | 0x01);
168 		dev_info(&PIIX4_dev->dev, "WARNING: SMBus interface set to "
169 			"new address %04x!\n", piix4_smba);
170 	} else if ((temp & 1) == 0) {
171 		if (force) {
172 			/* This should never need to be done, but has been
173 			 * noted that many Dell machines have the SMBus
174 			 * interface on the PIIX4 disabled!? NOTE: This assumes
175 			 * I/O space and other allocations WERE done by the
176 			 * Bios!  Don't complain if your hardware does weird
177 			 * things after enabling this. :') Check for Bios
178 			 * updates before resorting to this.
179 			 */
180 			pci_write_config_byte(PIIX4_dev, SMBHSTCFG,
181 					      temp | 1);
182 			dev_printk(KERN_NOTICE, &PIIX4_dev->dev,
183 				"WARNING: SMBus interface has been "
184 				"FORCEFULLY ENABLED!\n");
185 		} else {
186 			dev_err(&PIIX4_dev->dev,
187 				"Host SMBus controller not enabled!\n");
188 			release_region(piix4_smba, SMBIOSIZE);
189 			piix4_smba = 0;
190 			return -ENODEV;
191 		}
192 	}
193 
194 	if (((temp & 0x0E) == 8) || ((temp & 0x0E) == 2))
195 		dev_dbg(&PIIX4_dev->dev, "Using Interrupt 9 for SMBus.\n");
196 	else if ((temp & 0x0E) == 0)
197 		dev_dbg(&PIIX4_dev->dev, "Using Interrupt SMI# for SMBus.\n");
198 	else
199 		dev_err(&PIIX4_dev->dev, "Illegal Interrupt configuration "
200 			"(or code out of date)!\n");
201 
202 	pci_read_config_byte(PIIX4_dev, SMBREV, &temp);
203 	dev_dbg(&PIIX4_dev->dev, "SMBREV = 0x%X\n", temp);
204 	dev_dbg(&PIIX4_dev->dev, "SMBA = 0x%X\n", piix4_smba);
205 
206 	return 0;
207 }
208 
209 /* Another internally used function */
210 static int piix4_transaction(void)
211 {
212 	int temp;
213 	int result = 0;
214 	int timeout = 0;
215 
216 	dev_dbg(&piix4_adapter.dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
217 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
218 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
219 		inb_p(SMBHSTDAT1));
220 
221 	/* Make sure the SMBus host is ready to start transmitting */
222 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
223 		dev_dbg(&piix4_adapter.dev, "SMBus busy (%02x). "
224 			"Resetting...\n", temp);
225 		outb_p(temp, SMBHSTSTS);
226 		if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
227 			dev_err(&piix4_adapter.dev, "Failed! (%02x)\n", temp);
228 			return -1;
229 		} else {
230 			dev_dbg(&piix4_adapter.dev, "Successfull!\n");
231 		}
232 	}
233 
234 	/* start the transaction by setting bit 6 */
235 	outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);
236 
237 	/* We will always wait for a fraction of a second! (See PIIX4 docs errata) */
238 	do {
239 		msleep(1);
240 		temp = inb_p(SMBHSTSTS);
241 	} while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
242 
243 	/* If the SMBus is still busy, we give up */
244 	if (timeout >= MAX_TIMEOUT) {
245 		dev_err(&piix4_adapter.dev, "SMBus Timeout!\n");
246 		result = -1;
247 	}
248 
249 	if (temp & 0x10) {
250 		result = -1;
251 		dev_err(&piix4_adapter.dev, "Error: Failed bus transaction\n");
252 	}
253 
254 	if (temp & 0x08) {
255 		result = -1;
256 		dev_dbg(&piix4_adapter.dev, "Bus collision! SMBus may be "
257 			"locked until next hard reset. (sorry!)\n");
258 		/* Clock stops and slave is stuck in mid-transmission */
259 	}
260 
261 	if (temp & 0x04) {
262 		result = -1;
263 		dev_dbg(&piix4_adapter.dev, "Error: no response!\n");
264 	}
265 
266 	if (inb_p(SMBHSTSTS) != 0x00)
267 		outb_p(inb(SMBHSTSTS), SMBHSTSTS);
268 
269 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
270 		dev_err(&piix4_adapter.dev, "Failed reset at end of "
271 			"transaction (%02x)\n", temp);
272 	}
273 	dev_dbg(&piix4_adapter.dev, "Transaction (post): CNT=%02x, CMD=%02x, "
274 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
275 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
276 		inb_p(SMBHSTDAT1));
277 	return result;
278 }
279 
280 /* Return -1 on error. */
281 static s32 piix4_access(struct i2c_adapter * adap, u16 addr,
282 		 unsigned short flags, char read_write,
283 		 u8 command, int size, union i2c_smbus_data * data)
284 {
285 	int i, len;
286 
287 	switch (size) {
288 	case I2C_SMBUS_PROC_CALL:
289 		dev_err(&adap->dev, "I2C_SMBUS_PROC_CALL not supported!\n");
290 		return -1;
291 	case I2C_SMBUS_QUICK:
292 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
293 		       SMBHSTADD);
294 		size = PIIX4_QUICK;
295 		break;
296 	case I2C_SMBUS_BYTE:
297 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
298 		       SMBHSTADD);
299 		if (read_write == I2C_SMBUS_WRITE)
300 			outb_p(command, SMBHSTCMD);
301 		size = PIIX4_BYTE;
302 		break;
303 	case I2C_SMBUS_BYTE_DATA:
304 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
305 		       SMBHSTADD);
306 		outb_p(command, SMBHSTCMD);
307 		if (read_write == I2C_SMBUS_WRITE)
308 			outb_p(data->byte, SMBHSTDAT0);
309 		size = PIIX4_BYTE_DATA;
310 		break;
311 	case I2C_SMBUS_WORD_DATA:
312 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
313 		       SMBHSTADD);
314 		outb_p(command, SMBHSTCMD);
315 		if (read_write == I2C_SMBUS_WRITE) {
316 			outb_p(data->word & 0xff, SMBHSTDAT0);
317 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
318 		}
319 		size = PIIX4_WORD_DATA;
320 		break;
321 	case I2C_SMBUS_BLOCK_DATA:
322 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
323 		       SMBHSTADD);
324 		outb_p(command, SMBHSTCMD);
325 		if (read_write == I2C_SMBUS_WRITE) {
326 			len = data->block[0];
327 			if (len < 0)
328 				len = 0;
329 			if (len > 32)
330 				len = 32;
331 			outb_p(len, SMBHSTDAT0);
332 			i = inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
333 			for (i = 1; i <= len; i++)
334 				outb_p(data->block[i], SMBBLKDAT);
335 		}
336 		size = PIIX4_BLOCK_DATA;
337 		break;
338 	}
339 
340 	outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);
341 
342 	if (piix4_transaction())	/* Error in transaction */
343 		return -1;
344 
345 	if ((read_write == I2C_SMBUS_WRITE) || (size == PIIX4_QUICK))
346 		return 0;
347 
348 
349 	switch (size) {
350 	case PIIX4_BYTE:	/* Where is the result put? I assume here it is in
351 				   SMBHSTDAT0 but it might just as well be in the
352 				   SMBHSTCMD. No clue in the docs */
353 
354 		data->byte = inb_p(SMBHSTDAT0);
355 		break;
356 	case PIIX4_BYTE_DATA:
357 		data->byte = inb_p(SMBHSTDAT0);
358 		break;
359 	case PIIX4_WORD_DATA:
360 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
361 		break;
362 	case PIIX4_BLOCK_DATA:
363 		data->block[0] = inb_p(SMBHSTDAT0);
364 		i = inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
365 		for (i = 1; i <= data->block[0]; i++)
366 			data->block[i] = inb_p(SMBBLKDAT);
367 		break;
368 	}
369 	return 0;
370 }
371 
372 static u32 piix4_func(struct i2c_adapter *adapter)
373 {
374 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
375 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
376 	    I2C_FUNC_SMBUS_BLOCK_DATA;
377 }
378 
379 static const struct i2c_algorithm smbus_algorithm = {
380 	.smbus_xfer	= piix4_access,
381 	.functionality	= piix4_func,
382 };
383 
384 static struct i2c_adapter piix4_adapter = {
385 	.owner		= THIS_MODULE,
386 	.id		= I2C_HW_SMBUS_PIIX4,
387 	.class		= I2C_CLASS_HWMON,
388 	.algo		= &smbus_algorithm,
389 };
390 
391 static struct pci_device_id piix4_ids[] = {
392 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3),
393 	  .driver_data = 3 },
394 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP200_SMBUS),
395 	  .driver_data = 0 },
396 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP300_SMBUS),
397 	  .driver_data = 0 },
398 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS),
399 	  .driver_data = 0 },
400 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP600_SMBUS),
401 	  .driver_data = 0 },
402 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_OSB4),
403 	  .driver_data = 0 },
404 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_CSB5),
405 	  .driver_data = 0 },
406 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_CSB6),
407 	  .driver_data = 0 },
408 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_HT1000SB),
409 	  .driver_data = 0 },
410 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3),
411 	  .driver_data = 3 },
412 	{ PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_SLC90E66_3),
413 	  .driver_data = 0 },
414 	{ 0, }
415 };
416 
417 MODULE_DEVICE_TABLE (pci, piix4_ids);
418 
419 static int __devinit piix4_probe(struct pci_dev *dev,
420 				const struct pci_device_id *id)
421 {
422 	int retval;
423 
424 	retval = piix4_setup(dev, id);
425 	if (retval)
426 		return retval;
427 
428 	/* set up the sysfs linkage to our parent device */
429 	piix4_adapter.dev.parent = &dev->dev;
430 
431 	snprintf(piix4_adapter.name, sizeof(piix4_adapter.name),
432 		"SMBus PIIX4 adapter at %04x", piix4_smba);
433 
434 	if ((retval = i2c_add_adapter(&piix4_adapter))) {
435 		dev_err(&dev->dev, "Couldn't register adapter!\n");
436 		release_region(piix4_smba, SMBIOSIZE);
437 		piix4_smba = 0;
438 	}
439 
440 	return retval;
441 }
442 
443 static void __devexit piix4_remove(struct pci_dev *dev)
444 {
445 	if (piix4_smba) {
446 		i2c_del_adapter(&piix4_adapter);
447 		release_region(piix4_smba, SMBIOSIZE);
448 		piix4_smba = 0;
449 	}
450 }
451 
452 static struct pci_driver piix4_driver = {
453 	.name		= "piix4_smbus",
454 	.id_table	= piix4_ids,
455 	.probe		= piix4_probe,
456 	.remove		= __devexit_p(piix4_remove),
457 };
458 
459 static int __init i2c_piix4_init(void)
460 {
461 	return pci_register_driver(&piix4_driver);
462 }
463 
464 static void __exit i2c_piix4_exit(void)
465 {
466 	pci_unregister_driver(&piix4_driver);
467 }
468 
469 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
470 		"Philip Edelbrock <phil@netroedge.com>");
471 MODULE_DESCRIPTION("PIIX4 SMBus driver");
472 MODULE_LICENSE("GPL");
473 
474 module_init(i2c_piix4_init);
475 module_exit(i2c_piix4_exit);
476