xref: /openbmc/linux/drivers/i2c/busses/i2c-piix4.c (revision f42b3800)
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, SB700, SB800
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 	dev_info(&PIIX4_dev->dev, "Found %s device\n", pci_name(PIIX4_dev));
125 
126 	/* Don't access SMBus on IBM systems which get corrupted eeproms */
127 	if (dmi_check_system(piix4_dmi_table) &&
128 			PIIX4_dev->vendor == PCI_VENDOR_ID_INTEL) {
129 		dev_err(&PIIX4_dev->dev, "IBM system detected; this module "
130 			"may corrupt your serial eeprom! Refusing to load "
131 			"module!\n");
132 		return -EPERM;
133 	}
134 
135 	/* Determine the address of the SMBus areas */
136 	if (force_addr) {
137 		piix4_smba = force_addr & 0xfff0;
138 		force = 0;
139 	} else {
140 		pci_read_config_word(PIIX4_dev, SMBBA, &piix4_smba);
141 		piix4_smba &= 0xfff0;
142 		if(piix4_smba == 0) {
143 			dev_err(&PIIX4_dev->dev, "SMB base address "
144 				"uninitialized - upgrade BIOS or use "
145 				"force_addr=0xaddr\n");
146 			return -ENODEV;
147 		}
148 	}
149 
150 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
151 		dev_err(&PIIX4_dev->dev, "SMB region 0x%x already in use!\n",
152 			piix4_smba);
153 		return -ENODEV;
154 	}
155 
156 	pci_read_config_byte(PIIX4_dev, SMBHSTCFG, &temp);
157 
158 	/* If force_addr is set, we program the new address here. Just to make
159 	   sure, we disable the PIIX4 first. */
160 	if (force_addr) {
161 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp & 0xfe);
162 		pci_write_config_word(PIIX4_dev, SMBBA, piix4_smba);
163 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp | 0x01);
164 		dev_info(&PIIX4_dev->dev, "WARNING: SMBus interface set to "
165 			"new address %04x!\n", piix4_smba);
166 	} else if ((temp & 1) == 0) {
167 		if (force) {
168 			/* This should never need to be done, but has been
169 			 * noted that many Dell machines have the SMBus
170 			 * interface on the PIIX4 disabled!? NOTE: This assumes
171 			 * I/O space and other allocations WERE done by the
172 			 * Bios!  Don't complain if your hardware does weird
173 			 * things after enabling this. :') Check for Bios
174 			 * updates before resorting to this.
175 			 */
176 			pci_write_config_byte(PIIX4_dev, SMBHSTCFG,
177 					      temp | 1);
178 			dev_printk(KERN_NOTICE, &PIIX4_dev->dev,
179 				"WARNING: SMBus interface has been "
180 				"FORCEFULLY ENABLED!\n");
181 		} else {
182 			dev_err(&PIIX4_dev->dev,
183 				"Host SMBus controller not enabled!\n");
184 			release_region(piix4_smba, SMBIOSIZE);
185 			piix4_smba = 0;
186 			return -ENODEV;
187 		}
188 	}
189 
190 	if (((temp & 0x0E) == 8) || ((temp & 0x0E) == 2))
191 		dev_dbg(&PIIX4_dev->dev, "Using Interrupt 9 for SMBus.\n");
192 	else if ((temp & 0x0E) == 0)
193 		dev_dbg(&PIIX4_dev->dev, "Using Interrupt SMI# for SMBus.\n");
194 	else
195 		dev_err(&PIIX4_dev->dev, "Illegal Interrupt configuration "
196 			"(or code out of date)!\n");
197 
198 	pci_read_config_byte(PIIX4_dev, SMBREV, &temp);
199 	dev_dbg(&PIIX4_dev->dev, "SMBREV = 0x%X\n", temp);
200 	dev_dbg(&PIIX4_dev->dev, "SMBA = 0x%X\n", piix4_smba);
201 
202 	return 0;
203 }
204 
205 /* Another internally used function */
206 static int piix4_transaction(void)
207 {
208 	int temp;
209 	int result = 0;
210 	int timeout = 0;
211 
212 	dev_dbg(&piix4_adapter.dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
213 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
214 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
215 		inb_p(SMBHSTDAT1));
216 
217 	/* Make sure the SMBus host is ready to start transmitting */
218 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
219 		dev_dbg(&piix4_adapter.dev, "SMBus busy (%02x). "
220 			"Resetting...\n", temp);
221 		outb_p(temp, SMBHSTSTS);
222 		if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
223 			dev_err(&piix4_adapter.dev, "Failed! (%02x)\n", temp);
224 			return -1;
225 		} else {
226 			dev_dbg(&piix4_adapter.dev, "Successfull!\n");
227 		}
228 	}
229 
230 	/* start the transaction by setting bit 6 */
231 	outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);
232 
233 	/* We will always wait for a fraction of a second! (See PIIX4 docs errata) */
234 	do {
235 		msleep(1);
236 		temp = inb_p(SMBHSTSTS);
237 	} while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
238 
239 	/* If the SMBus is still busy, we give up */
240 	if (timeout >= MAX_TIMEOUT) {
241 		dev_err(&piix4_adapter.dev, "SMBus Timeout!\n");
242 		result = -1;
243 	}
244 
245 	if (temp & 0x10) {
246 		result = -1;
247 		dev_err(&piix4_adapter.dev, "Error: Failed bus transaction\n");
248 	}
249 
250 	if (temp & 0x08) {
251 		result = -1;
252 		dev_dbg(&piix4_adapter.dev, "Bus collision! SMBus may be "
253 			"locked until next hard reset. (sorry!)\n");
254 		/* Clock stops and slave is stuck in mid-transmission */
255 	}
256 
257 	if (temp & 0x04) {
258 		result = -1;
259 		dev_dbg(&piix4_adapter.dev, "Error: no response!\n");
260 	}
261 
262 	if (inb_p(SMBHSTSTS) != 0x00)
263 		outb_p(inb(SMBHSTSTS), SMBHSTSTS);
264 
265 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
266 		dev_err(&piix4_adapter.dev, "Failed reset at end of "
267 			"transaction (%02x)\n", temp);
268 	}
269 	dev_dbg(&piix4_adapter.dev, "Transaction (post): CNT=%02x, CMD=%02x, "
270 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
271 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
272 		inb_p(SMBHSTDAT1));
273 	return result;
274 }
275 
276 /* Return -1 on error. */
277 static s32 piix4_access(struct i2c_adapter * adap, u16 addr,
278 		 unsigned short flags, char read_write,
279 		 u8 command, int size, union i2c_smbus_data * data)
280 {
281 	int i, len;
282 
283 	switch (size) {
284 	case I2C_SMBUS_PROC_CALL:
285 		dev_err(&adap->dev, "I2C_SMBUS_PROC_CALL not supported!\n");
286 		return -1;
287 	case I2C_SMBUS_QUICK:
288 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
289 		       SMBHSTADD);
290 		size = PIIX4_QUICK;
291 		break;
292 	case I2C_SMBUS_BYTE:
293 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
294 		       SMBHSTADD);
295 		if (read_write == I2C_SMBUS_WRITE)
296 			outb_p(command, SMBHSTCMD);
297 		size = PIIX4_BYTE;
298 		break;
299 	case I2C_SMBUS_BYTE_DATA:
300 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
301 		       SMBHSTADD);
302 		outb_p(command, SMBHSTCMD);
303 		if (read_write == I2C_SMBUS_WRITE)
304 			outb_p(data->byte, SMBHSTDAT0);
305 		size = PIIX4_BYTE_DATA;
306 		break;
307 	case I2C_SMBUS_WORD_DATA:
308 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
309 		       SMBHSTADD);
310 		outb_p(command, SMBHSTCMD);
311 		if (read_write == I2C_SMBUS_WRITE) {
312 			outb_p(data->word & 0xff, SMBHSTDAT0);
313 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
314 		}
315 		size = PIIX4_WORD_DATA;
316 		break;
317 	case I2C_SMBUS_BLOCK_DATA:
318 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
319 		       SMBHSTADD);
320 		outb_p(command, SMBHSTCMD);
321 		if (read_write == I2C_SMBUS_WRITE) {
322 			len = data->block[0];
323 			if (len < 0)
324 				len = 0;
325 			if (len > 32)
326 				len = 32;
327 			outb_p(len, SMBHSTDAT0);
328 			i = inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
329 			for (i = 1; i <= len; i++)
330 				outb_p(data->block[i], SMBBLKDAT);
331 		}
332 		size = PIIX4_BLOCK_DATA;
333 		break;
334 	}
335 
336 	outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);
337 
338 	if (piix4_transaction())	/* Error in transaction */
339 		return -1;
340 
341 	if ((read_write == I2C_SMBUS_WRITE) || (size == PIIX4_QUICK))
342 		return 0;
343 
344 
345 	switch (size) {
346 	case PIIX4_BYTE:	/* Where is the result put? I assume here it is in
347 				   SMBHSTDAT0 but it might just as well be in the
348 				   SMBHSTCMD. No clue in the docs */
349 
350 		data->byte = inb_p(SMBHSTDAT0);
351 		break;
352 	case PIIX4_BYTE_DATA:
353 		data->byte = inb_p(SMBHSTDAT0);
354 		break;
355 	case PIIX4_WORD_DATA:
356 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
357 		break;
358 	case PIIX4_BLOCK_DATA:
359 		data->block[0] = inb_p(SMBHSTDAT0);
360 		i = inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
361 		for (i = 1; i <= data->block[0]; i++)
362 			data->block[i] = inb_p(SMBBLKDAT);
363 		break;
364 	}
365 	return 0;
366 }
367 
368 static u32 piix4_func(struct i2c_adapter *adapter)
369 {
370 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
371 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
372 	    I2C_FUNC_SMBUS_BLOCK_DATA;
373 }
374 
375 static const struct i2c_algorithm smbus_algorithm = {
376 	.smbus_xfer	= piix4_access,
377 	.functionality	= piix4_func,
378 };
379 
380 static struct i2c_adapter piix4_adapter = {
381 	.owner		= THIS_MODULE,
382 	.id		= I2C_HW_SMBUS_PIIX4,
383 	.class		= I2C_CLASS_HWMON,
384 	.algo		= &smbus_algorithm,
385 };
386 
387 static struct pci_device_id piix4_ids[] = {
388 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
389 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3) },
390 	{ PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_SLC90E66_3) },
391 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP200_SMBUS) },
392 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP300_SMBUS) },
393 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS) },
394 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS) },
395 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
396 		     PCI_DEVICE_ID_SERVERWORKS_OSB4) },
397 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
398 		     PCI_DEVICE_ID_SERVERWORKS_CSB5) },
399 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
400 		     PCI_DEVICE_ID_SERVERWORKS_CSB6) },
401 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
402 		     PCI_DEVICE_ID_SERVERWORKS_HT1000SB) },
403 	{ 0, }
404 };
405 
406 MODULE_DEVICE_TABLE (pci, piix4_ids);
407 
408 static int __devinit piix4_probe(struct pci_dev *dev,
409 				const struct pci_device_id *id)
410 {
411 	int retval;
412 
413 	retval = piix4_setup(dev, id);
414 	if (retval)
415 		return retval;
416 
417 	/* set up the sysfs linkage to our parent device */
418 	piix4_adapter.dev.parent = &dev->dev;
419 
420 	snprintf(piix4_adapter.name, sizeof(piix4_adapter.name),
421 		"SMBus PIIX4 adapter at %04x", piix4_smba);
422 
423 	if ((retval = i2c_add_adapter(&piix4_adapter))) {
424 		dev_err(&dev->dev, "Couldn't register adapter!\n");
425 		release_region(piix4_smba, SMBIOSIZE);
426 		piix4_smba = 0;
427 	}
428 
429 	return retval;
430 }
431 
432 static void __devexit piix4_remove(struct pci_dev *dev)
433 {
434 	if (piix4_smba) {
435 		i2c_del_adapter(&piix4_adapter);
436 		release_region(piix4_smba, SMBIOSIZE);
437 		piix4_smba = 0;
438 	}
439 }
440 
441 static struct pci_driver piix4_driver = {
442 	.name		= "piix4_smbus",
443 	.id_table	= piix4_ids,
444 	.probe		= piix4_probe,
445 	.remove		= __devexit_p(piix4_remove),
446 };
447 
448 static int __init i2c_piix4_init(void)
449 {
450 	return pci_register_driver(&piix4_driver);
451 }
452 
453 static void __exit i2c_piix4_exit(void)
454 {
455 	pci_unregister_driver(&piix4_driver);
456 }
457 
458 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
459 		"Philip Edelbrock <phil@netroedge.com>");
460 MODULE_DESCRIPTION("PIIX4 SMBus driver");
461 MODULE_LICENSE("GPL");
462 
463 module_init(i2c_piix4_init);
464 module_exit(i2c_piix4_exit);
465