xref: /openbmc/linux/drivers/i2c/busses/i2c-piix4.c (revision 1c2dd16a)
1 /*
2     Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl> and
3     Philip Edelbrock <phil@netroedge.com>
4 
5     This program is free software; you can redistribute it and/or modify
6     it under the terms of the GNU General Public License as published by
7     the Free Software Foundation; either version 2 of the License, or
8     (at your option) any later version.
9 
10     This program is distributed in the hope that it will be useful,
11     but WITHOUT ANY WARRANTY; without even the implied warranty of
12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13     GNU General Public License for more details.
14 */
15 
16 /*
17    Supports:
18 	Intel PIIX4, 440MX
19 	Serverworks OSB4, CSB5, CSB6, HT-1000, HT-1100
20 	ATI IXP200, IXP300, IXP400, SB600, SB700/SP5100, SB800
21 	AMD Hudson-2, ML, CZ
22 	SMSC Victory66
23 
24    Note: we assume there can only be one device, with one or more
25    SMBus interfaces.
26    The device can register multiple i2c_adapters (up to PIIX4_MAX_ADAPTERS).
27    For devices supporting multiple ports the i2c_adapter should provide
28    an i2c_algorithm to access them.
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/ioport.h>
38 #include <linux/i2c.h>
39 #include <linux/slab.h>
40 #include <linux/dmi.h>
41 #include <linux/acpi.h>
42 #include <linux/io.h>
43 #include <linux/mutex.h>
44 
45 
46 /* PIIX4 SMBus address offsets */
47 #define SMBHSTSTS	(0 + piix4_smba)
48 #define SMBHSLVSTS	(1 + piix4_smba)
49 #define SMBHSTCNT	(2 + piix4_smba)
50 #define SMBHSTCMD	(3 + piix4_smba)
51 #define SMBHSTADD	(4 + piix4_smba)
52 #define SMBHSTDAT0	(5 + piix4_smba)
53 #define SMBHSTDAT1	(6 + piix4_smba)
54 #define SMBBLKDAT	(7 + piix4_smba)
55 #define SMBSLVCNT	(8 + piix4_smba)
56 #define SMBSHDWCMD	(9 + piix4_smba)
57 #define SMBSLVEVT	(0xA + piix4_smba)
58 #define SMBSLVDAT	(0xC + piix4_smba)
59 
60 /* count for request_region */
61 #define SMBIOSIZE	9
62 
63 /* PCI Address Constants */
64 #define SMBBA		0x090
65 #define SMBHSTCFG	0x0D2
66 #define SMBSLVC		0x0D3
67 #define SMBSHDW1	0x0D4
68 #define SMBSHDW2	0x0D5
69 #define SMBREV		0x0D6
70 
71 /* Other settings */
72 #define MAX_TIMEOUT	500
73 #define  ENABLE_INT9	0
74 
75 /* PIIX4 constants */
76 #define PIIX4_QUICK		0x00
77 #define PIIX4_BYTE		0x04
78 #define PIIX4_BYTE_DATA		0x08
79 #define PIIX4_WORD_DATA		0x0C
80 #define PIIX4_BLOCK_DATA	0x14
81 
82 /* Multi-port constants */
83 #define PIIX4_MAX_ADAPTERS 4
84 
85 /* SB800 constants */
86 #define SB800_PIIX4_SMB_IDX		0xcd6
87 
88 /*
89  * SB800 port is selected by bits 2:1 of the smb_en register (0x2c)
90  * or the smb_sel register (0x2e), depending on bit 0 of register 0x2f.
91  * Hudson-2/Bolton port is always selected by bits 2:1 of register 0x2f.
92  */
93 #define SB800_PIIX4_PORT_IDX		0x2c
94 #define SB800_PIIX4_PORT_IDX_ALT	0x2e
95 #define SB800_PIIX4_PORT_IDX_SEL	0x2f
96 #define SB800_PIIX4_PORT_IDX_MASK	0x06
97 
98 /* insmod parameters */
99 
100 /* If force is set to anything different from 0, we forcibly enable the
101    PIIX4. DANGEROUS! */
102 static int force;
103 module_param (force, int, 0);
104 MODULE_PARM_DESC(force, "Forcibly enable the PIIX4. DANGEROUS!");
105 
106 /* If force_addr is set to anything different from 0, we forcibly enable
107    the PIIX4 at the given address. VERY DANGEROUS! */
108 static int force_addr;
109 module_param (force_addr, int, 0);
110 MODULE_PARM_DESC(force_addr,
111 		 "Forcibly enable the PIIX4 at the given address. "
112 		 "EXTREMELY DANGEROUS!");
113 
114 static int srvrworks_csb5_delay;
115 static struct pci_driver piix4_driver;
116 
117 static const struct dmi_system_id piix4_dmi_blacklist[] = {
118 	{
119 		.ident = "Sapphire AM2RD790",
120 		.matches = {
121 			DMI_MATCH(DMI_BOARD_VENDOR, "SAPPHIRE Inc."),
122 			DMI_MATCH(DMI_BOARD_NAME, "PC-AM2RD790"),
123 		},
124 	},
125 	{
126 		.ident = "DFI Lanparty UT 790FX",
127 		.matches = {
128 			DMI_MATCH(DMI_BOARD_VENDOR, "DFI Inc."),
129 			DMI_MATCH(DMI_BOARD_NAME, "LP UT 790FX"),
130 		},
131 	},
132 	{ }
133 };
134 
135 /* The IBM entry is in a separate table because we only check it
136    on Intel-based systems */
137 static const struct dmi_system_id piix4_dmi_ibm[] = {
138 	{
139 		.ident = "IBM",
140 		.matches = { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
141 	},
142 	{ },
143 };
144 
145 /*
146  * SB800 globals
147  * piix4_mutex_sb800 protects piix4_port_sel_sb800 and the pair
148  * of I/O ports at SB800_PIIX4_SMB_IDX.
149  */
150 static DEFINE_MUTEX(piix4_mutex_sb800);
151 static u8 piix4_port_sel_sb800;
152 static const char *piix4_main_port_names_sb800[PIIX4_MAX_ADAPTERS] = {
153 	" port 0", " port 2", " port 3", " port 4"
154 };
155 static const char *piix4_aux_port_name_sb800 = " port 1";
156 
157 struct i2c_piix4_adapdata {
158 	unsigned short smba;
159 
160 	/* SB800 */
161 	bool sb800_main;
162 	u8 port;		/* Port number, shifted */
163 };
164 
165 static int piix4_setup(struct pci_dev *PIIX4_dev,
166 		       const struct pci_device_id *id)
167 {
168 	unsigned char temp;
169 	unsigned short piix4_smba;
170 
171 	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_SERVERWORKS) &&
172 	    (PIIX4_dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB5))
173 		srvrworks_csb5_delay = 1;
174 
175 	/* On some motherboards, it was reported that accessing the SMBus
176 	   caused severe hardware problems */
177 	if (dmi_check_system(piix4_dmi_blacklist)) {
178 		dev_err(&PIIX4_dev->dev,
179 			"Accessing the SMBus on this system is unsafe!\n");
180 		return -EPERM;
181 	}
182 
183 	/* Don't access SMBus on IBM systems which get corrupted eeproms */
184 	if (dmi_check_system(piix4_dmi_ibm) &&
185 			PIIX4_dev->vendor == PCI_VENDOR_ID_INTEL) {
186 		dev_err(&PIIX4_dev->dev, "IBM system detected; this module "
187 			"may corrupt your serial eeprom! Refusing to load "
188 			"module!\n");
189 		return -EPERM;
190 	}
191 
192 	/* Determine the address of the SMBus areas */
193 	if (force_addr) {
194 		piix4_smba = force_addr & 0xfff0;
195 		force = 0;
196 	} else {
197 		pci_read_config_word(PIIX4_dev, SMBBA, &piix4_smba);
198 		piix4_smba &= 0xfff0;
199 		if(piix4_smba == 0) {
200 			dev_err(&PIIX4_dev->dev, "SMBus base address "
201 				"uninitialized - upgrade BIOS or use "
202 				"force_addr=0xaddr\n");
203 			return -ENODEV;
204 		}
205 	}
206 
207 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
208 		return -ENODEV;
209 
210 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
211 		dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
212 			piix4_smba);
213 		return -EBUSY;
214 	}
215 
216 	pci_read_config_byte(PIIX4_dev, SMBHSTCFG, &temp);
217 
218 	/* If force_addr is set, we program the new address here. Just to make
219 	   sure, we disable the PIIX4 first. */
220 	if (force_addr) {
221 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp & 0xfe);
222 		pci_write_config_word(PIIX4_dev, SMBBA, piix4_smba);
223 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp | 0x01);
224 		dev_info(&PIIX4_dev->dev, "WARNING: SMBus interface set to "
225 			"new address %04x!\n", piix4_smba);
226 	} else if ((temp & 1) == 0) {
227 		if (force) {
228 			/* This should never need to be done, but has been
229 			 * noted that many Dell machines have the SMBus
230 			 * interface on the PIIX4 disabled!? NOTE: This assumes
231 			 * I/O space and other allocations WERE done by the
232 			 * Bios!  Don't complain if your hardware does weird
233 			 * things after enabling this. :') Check for Bios
234 			 * updates before resorting to this.
235 			 */
236 			pci_write_config_byte(PIIX4_dev, SMBHSTCFG,
237 					      temp | 1);
238 			dev_notice(&PIIX4_dev->dev,
239 				   "WARNING: SMBus interface has been FORCEFULLY ENABLED!\n");
240 		} else {
241 			dev_err(&PIIX4_dev->dev,
242 				"SMBus Host Controller not enabled!\n");
243 			release_region(piix4_smba, SMBIOSIZE);
244 			return -ENODEV;
245 		}
246 	}
247 
248 	if (((temp & 0x0E) == 8) || ((temp & 0x0E) == 2))
249 		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
250 	else if ((temp & 0x0E) == 0)
251 		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");
252 	else
253 		dev_err(&PIIX4_dev->dev, "Illegal Interrupt configuration "
254 			"(or code out of date)!\n");
255 
256 	pci_read_config_byte(PIIX4_dev, SMBREV, &temp);
257 	dev_info(&PIIX4_dev->dev,
258 		 "SMBus Host Controller at 0x%x, revision %d\n",
259 		 piix4_smba, temp);
260 
261 	return piix4_smba;
262 }
263 
264 static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
265 			     const struct pci_device_id *id, u8 aux)
266 {
267 	unsigned short piix4_smba;
268 	u8 smba_en_lo, smba_en_hi, smb_en, smb_en_status, port_sel;
269 	u8 i2ccfg, i2ccfg_offset = 0x10;
270 
271 	/* SB800 and later SMBus does not support forcing address */
272 	if (force || force_addr) {
273 		dev_err(&PIIX4_dev->dev, "SMBus does not support "
274 			"forcing address!\n");
275 		return -EINVAL;
276 	}
277 
278 	/* Determine the address of the SMBus areas */
279 	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
280 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
281 	     PIIX4_dev->revision >= 0x41) ||
282 	    (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
283 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
284 	     PIIX4_dev->revision >= 0x49))
285 		smb_en = 0x00;
286 	else
287 		smb_en = (aux) ? 0x28 : 0x2c;
288 
289 	mutex_lock(&piix4_mutex_sb800);
290 	outb_p(smb_en, SB800_PIIX4_SMB_IDX);
291 	smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
292 	outb_p(smb_en + 1, SB800_PIIX4_SMB_IDX);
293 	smba_en_hi = inb_p(SB800_PIIX4_SMB_IDX + 1);
294 	mutex_unlock(&piix4_mutex_sb800);
295 
296 	if (!smb_en) {
297 		smb_en_status = smba_en_lo & 0x10;
298 		piix4_smba = smba_en_hi << 8;
299 		if (aux)
300 			piix4_smba |= 0x20;
301 	} else {
302 		smb_en_status = smba_en_lo & 0x01;
303 		piix4_smba = ((smba_en_hi << 8) | smba_en_lo) & 0xffe0;
304 	}
305 
306 	if (!smb_en_status) {
307 		dev_err(&PIIX4_dev->dev,
308 			"SMBus Host Controller not enabled!\n");
309 		return -ENODEV;
310 	}
311 
312 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
313 		return -ENODEV;
314 
315 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
316 		dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
317 			piix4_smba);
318 		return -EBUSY;
319 	}
320 
321 	/* Aux SMBus does not support IRQ information */
322 	if (aux) {
323 		dev_info(&PIIX4_dev->dev,
324 			 "Auxiliary SMBus Host Controller at 0x%x\n",
325 			 piix4_smba);
326 		return piix4_smba;
327 	}
328 
329 	/* Request the SMBus I2C bus config region */
330 	if (!request_region(piix4_smba + i2ccfg_offset, 1, "i2ccfg")) {
331 		dev_err(&PIIX4_dev->dev, "SMBus I2C bus config region "
332 			"0x%x already in use!\n", piix4_smba + i2ccfg_offset);
333 		release_region(piix4_smba, SMBIOSIZE);
334 		return -EBUSY;
335 	}
336 	i2ccfg = inb_p(piix4_smba + i2ccfg_offset);
337 	release_region(piix4_smba + i2ccfg_offset, 1);
338 
339 	if (i2ccfg & 1)
340 		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
341 	else
342 		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");
343 
344 	dev_info(&PIIX4_dev->dev,
345 		 "SMBus Host Controller at 0x%x, revision %d\n",
346 		 piix4_smba, i2ccfg >> 4);
347 
348 	/* Find which register is used for port selection */
349 	if (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD) {
350 		piix4_port_sel_sb800 = SB800_PIIX4_PORT_IDX_ALT;
351 	} else {
352 		mutex_lock(&piix4_mutex_sb800);
353 		outb_p(SB800_PIIX4_PORT_IDX_SEL, SB800_PIIX4_SMB_IDX);
354 		port_sel = inb_p(SB800_PIIX4_SMB_IDX + 1);
355 		piix4_port_sel_sb800 = (port_sel & 0x01) ?
356 				       SB800_PIIX4_PORT_IDX_ALT :
357 				       SB800_PIIX4_PORT_IDX;
358 		mutex_unlock(&piix4_mutex_sb800);
359 	}
360 
361 	dev_info(&PIIX4_dev->dev,
362 		 "Using register 0x%02x for SMBus port selection\n",
363 		 (unsigned int)piix4_port_sel_sb800);
364 
365 	return piix4_smba;
366 }
367 
368 static int piix4_setup_aux(struct pci_dev *PIIX4_dev,
369 			   const struct pci_device_id *id,
370 			   unsigned short base_reg_addr)
371 {
372 	/* Set up auxiliary SMBus controllers found on some
373 	 * AMD chipsets e.g. SP5100 (SB700 derivative) */
374 
375 	unsigned short piix4_smba;
376 
377 	/* Read address of auxiliary SMBus controller */
378 	pci_read_config_word(PIIX4_dev, base_reg_addr, &piix4_smba);
379 	if ((piix4_smba & 1) == 0) {
380 		dev_dbg(&PIIX4_dev->dev,
381 			"Auxiliary SMBus controller not enabled\n");
382 		return -ENODEV;
383 	}
384 
385 	piix4_smba &= 0xfff0;
386 	if (piix4_smba == 0) {
387 		dev_dbg(&PIIX4_dev->dev,
388 			"Auxiliary SMBus base address uninitialized\n");
389 		return -ENODEV;
390 	}
391 
392 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
393 		return -ENODEV;
394 
395 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
396 		dev_err(&PIIX4_dev->dev, "Auxiliary SMBus region 0x%x "
397 			"already in use!\n", piix4_smba);
398 		return -EBUSY;
399 	}
400 
401 	dev_info(&PIIX4_dev->dev,
402 		 "Auxiliary SMBus Host Controller at 0x%x\n",
403 		 piix4_smba);
404 
405 	return piix4_smba;
406 }
407 
408 static int piix4_transaction(struct i2c_adapter *piix4_adapter)
409 {
410 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(piix4_adapter);
411 	unsigned short piix4_smba = adapdata->smba;
412 	int temp;
413 	int result = 0;
414 	int timeout = 0;
415 
416 	dev_dbg(&piix4_adapter->dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
417 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
418 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
419 		inb_p(SMBHSTDAT1));
420 
421 	/* Make sure the SMBus host is ready to start transmitting */
422 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
423 		dev_dbg(&piix4_adapter->dev, "SMBus busy (%02x). "
424 			"Resetting...\n", temp);
425 		outb_p(temp, SMBHSTSTS);
426 		if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
427 			dev_err(&piix4_adapter->dev, "Failed! (%02x)\n", temp);
428 			return -EBUSY;
429 		} else {
430 			dev_dbg(&piix4_adapter->dev, "Successful!\n");
431 		}
432 	}
433 
434 	/* start the transaction by setting bit 6 */
435 	outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);
436 
437 	/* We will always wait for a fraction of a second! (See PIIX4 docs errata) */
438 	if (srvrworks_csb5_delay) /* Extra delay for SERVERWORKS_CSB5 */
439 		msleep(2);
440 	else
441 		msleep(1);
442 
443 	while ((++timeout < MAX_TIMEOUT) &&
444 	       ((temp = inb_p(SMBHSTSTS)) & 0x01))
445 		msleep(1);
446 
447 	/* If the SMBus is still busy, we give up */
448 	if (timeout == MAX_TIMEOUT) {
449 		dev_err(&piix4_adapter->dev, "SMBus Timeout!\n");
450 		result = -ETIMEDOUT;
451 	}
452 
453 	if (temp & 0x10) {
454 		result = -EIO;
455 		dev_err(&piix4_adapter->dev, "Error: Failed bus transaction\n");
456 	}
457 
458 	if (temp & 0x08) {
459 		result = -EIO;
460 		dev_dbg(&piix4_adapter->dev, "Bus collision! SMBus may be "
461 			"locked until next hard reset. (sorry!)\n");
462 		/* Clock stops and slave is stuck in mid-transmission */
463 	}
464 
465 	if (temp & 0x04) {
466 		result = -ENXIO;
467 		dev_dbg(&piix4_adapter->dev, "Error: no response!\n");
468 	}
469 
470 	if (inb_p(SMBHSTSTS) != 0x00)
471 		outb_p(inb(SMBHSTSTS), SMBHSTSTS);
472 
473 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
474 		dev_err(&piix4_adapter->dev, "Failed reset at end of "
475 			"transaction (%02x)\n", temp);
476 	}
477 	dev_dbg(&piix4_adapter->dev, "Transaction (post): CNT=%02x, CMD=%02x, "
478 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
479 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
480 		inb_p(SMBHSTDAT1));
481 	return result;
482 }
483 
484 /* Return negative errno on error. */
485 static s32 piix4_access(struct i2c_adapter * adap, u16 addr,
486 		 unsigned short flags, char read_write,
487 		 u8 command, int size, union i2c_smbus_data * data)
488 {
489 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
490 	unsigned short piix4_smba = adapdata->smba;
491 	int i, len;
492 	int status;
493 
494 	switch (size) {
495 	case I2C_SMBUS_QUICK:
496 		outb_p((addr << 1) | read_write,
497 		       SMBHSTADD);
498 		size = PIIX4_QUICK;
499 		break;
500 	case I2C_SMBUS_BYTE:
501 		outb_p((addr << 1) | read_write,
502 		       SMBHSTADD);
503 		if (read_write == I2C_SMBUS_WRITE)
504 			outb_p(command, SMBHSTCMD);
505 		size = PIIX4_BYTE;
506 		break;
507 	case I2C_SMBUS_BYTE_DATA:
508 		outb_p((addr << 1) | read_write,
509 		       SMBHSTADD);
510 		outb_p(command, SMBHSTCMD);
511 		if (read_write == I2C_SMBUS_WRITE)
512 			outb_p(data->byte, SMBHSTDAT0);
513 		size = PIIX4_BYTE_DATA;
514 		break;
515 	case I2C_SMBUS_WORD_DATA:
516 		outb_p((addr << 1) | read_write,
517 		       SMBHSTADD);
518 		outb_p(command, SMBHSTCMD);
519 		if (read_write == I2C_SMBUS_WRITE) {
520 			outb_p(data->word & 0xff, SMBHSTDAT0);
521 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
522 		}
523 		size = PIIX4_WORD_DATA;
524 		break;
525 	case I2C_SMBUS_BLOCK_DATA:
526 		outb_p((addr << 1) | read_write,
527 		       SMBHSTADD);
528 		outb_p(command, SMBHSTCMD);
529 		if (read_write == I2C_SMBUS_WRITE) {
530 			len = data->block[0];
531 			if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
532 				return -EINVAL;
533 			outb_p(len, SMBHSTDAT0);
534 			inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
535 			for (i = 1; i <= len; i++)
536 				outb_p(data->block[i], SMBBLKDAT);
537 		}
538 		size = PIIX4_BLOCK_DATA;
539 		break;
540 	default:
541 		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
542 		return -EOPNOTSUPP;
543 	}
544 
545 	outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);
546 
547 	status = piix4_transaction(adap);
548 	if (status)
549 		return status;
550 
551 	if ((read_write == I2C_SMBUS_WRITE) || (size == PIIX4_QUICK))
552 		return 0;
553 
554 
555 	switch (size) {
556 	case PIIX4_BYTE:
557 	case PIIX4_BYTE_DATA:
558 		data->byte = inb_p(SMBHSTDAT0);
559 		break;
560 	case PIIX4_WORD_DATA:
561 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
562 		break;
563 	case PIIX4_BLOCK_DATA:
564 		data->block[0] = inb_p(SMBHSTDAT0);
565 		if (data->block[0] == 0 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
566 			return -EPROTO;
567 		inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
568 		for (i = 1; i <= data->block[0]; i++)
569 			data->block[i] = inb_p(SMBBLKDAT);
570 		break;
571 	}
572 	return 0;
573 }
574 
575 /*
576  * Handles access to multiple SMBus ports on the SB800.
577  * The port is selected by bits 2:1 of the smb_en register (0x2c).
578  * Returns negative errno on error.
579  *
580  * Note: The selected port must be returned to the initial selection to avoid
581  * problems on certain systems.
582  */
583 static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
584 		 unsigned short flags, char read_write,
585 		 u8 command, int size, union i2c_smbus_data *data)
586 {
587 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
588 	unsigned short piix4_smba = adapdata->smba;
589 	int retries = MAX_TIMEOUT;
590 	int smbslvcnt;
591 	u8 smba_en_lo;
592 	u8 port;
593 	int retval;
594 
595 	mutex_lock(&piix4_mutex_sb800);
596 
597 	/* Request the SMBUS semaphore, avoid conflicts with the IMC */
598 	smbslvcnt  = inb_p(SMBSLVCNT);
599 	do {
600 		outb_p(smbslvcnt | 0x10, SMBSLVCNT);
601 
602 		/* Check the semaphore status */
603 		smbslvcnt  = inb_p(SMBSLVCNT);
604 		if (smbslvcnt & 0x10)
605 			break;
606 
607 		usleep_range(1000, 2000);
608 	} while (--retries);
609 	/* SMBus is still owned by the IMC, we give up */
610 	if (!retries) {
611 		mutex_unlock(&piix4_mutex_sb800);
612 		return -EBUSY;
613 	}
614 
615 	outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX);
616 	smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
617 
618 	port = adapdata->port;
619 	if ((smba_en_lo & SB800_PIIX4_PORT_IDX_MASK) != port)
620 		outb_p((smba_en_lo & ~SB800_PIIX4_PORT_IDX_MASK) | port,
621 		       SB800_PIIX4_SMB_IDX + 1);
622 
623 	retval = piix4_access(adap, addr, flags, read_write,
624 			      command, size, data);
625 
626 	outb_p(smba_en_lo, SB800_PIIX4_SMB_IDX + 1);
627 
628 	/* Release the semaphore */
629 	outb_p(smbslvcnt | 0x20, SMBSLVCNT);
630 
631 	mutex_unlock(&piix4_mutex_sb800);
632 
633 	return retval;
634 }
635 
636 static u32 piix4_func(struct i2c_adapter *adapter)
637 {
638 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
639 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
640 	    I2C_FUNC_SMBUS_BLOCK_DATA;
641 }
642 
643 static const struct i2c_algorithm smbus_algorithm = {
644 	.smbus_xfer	= piix4_access,
645 	.functionality	= piix4_func,
646 };
647 
648 static const struct i2c_algorithm piix4_smbus_algorithm_sb800 = {
649 	.smbus_xfer	= piix4_access_sb800,
650 	.functionality	= piix4_func,
651 };
652 
653 static const struct pci_device_id piix4_ids[] = {
654 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
655 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3) },
656 	{ PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_SLC90E66_3) },
657 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP200_SMBUS) },
658 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP300_SMBUS) },
659 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS) },
660 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS) },
661 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) },
662 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) },
663 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
664 		     PCI_DEVICE_ID_SERVERWORKS_OSB4) },
665 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
666 		     PCI_DEVICE_ID_SERVERWORKS_CSB5) },
667 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
668 		     PCI_DEVICE_ID_SERVERWORKS_CSB6) },
669 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
670 		     PCI_DEVICE_ID_SERVERWORKS_HT1000SB) },
671 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
672 		     PCI_DEVICE_ID_SERVERWORKS_HT1100LD) },
673 	{ 0, }
674 };
675 
676 MODULE_DEVICE_TABLE (pci, piix4_ids);
677 
678 static struct i2c_adapter *piix4_main_adapters[PIIX4_MAX_ADAPTERS];
679 static struct i2c_adapter *piix4_aux_adapter;
680 
681 static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
682 			     bool sb800_main, u8 port,
683 			     const char *name, struct i2c_adapter **padap)
684 {
685 	struct i2c_adapter *adap;
686 	struct i2c_piix4_adapdata *adapdata;
687 	int retval;
688 
689 	adap = kzalloc(sizeof(*adap), GFP_KERNEL);
690 	if (adap == NULL) {
691 		release_region(smba, SMBIOSIZE);
692 		return -ENOMEM;
693 	}
694 
695 	adap->owner = THIS_MODULE;
696 	adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
697 	adap->algo = sb800_main ? &piix4_smbus_algorithm_sb800
698 				: &smbus_algorithm;
699 
700 	adapdata = kzalloc(sizeof(*adapdata), GFP_KERNEL);
701 	if (adapdata == NULL) {
702 		kfree(adap);
703 		release_region(smba, SMBIOSIZE);
704 		return -ENOMEM;
705 	}
706 
707 	adapdata->smba = smba;
708 	adapdata->sb800_main = sb800_main;
709 	adapdata->port = port << 1;
710 
711 	/* set up the sysfs linkage to our parent device */
712 	adap->dev.parent = &dev->dev;
713 
714 	snprintf(adap->name, sizeof(adap->name),
715 		"SMBus PIIX4 adapter%s at %04x", name, smba);
716 
717 	i2c_set_adapdata(adap, adapdata);
718 
719 	retval = i2c_add_adapter(adap);
720 	if (retval) {
721 		kfree(adapdata);
722 		kfree(adap);
723 		release_region(smba, SMBIOSIZE);
724 		return retval;
725 	}
726 
727 	*padap = adap;
728 	return 0;
729 }
730 
731 static int piix4_add_adapters_sb800(struct pci_dev *dev, unsigned short smba)
732 {
733 	struct i2c_piix4_adapdata *adapdata;
734 	int port;
735 	int retval;
736 
737 	for (port = 0; port < PIIX4_MAX_ADAPTERS; port++) {
738 		retval = piix4_add_adapter(dev, smba, true, port,
739 					   piix4_main_port_names_sb800[port],
740 					   &piix4_main_adapters[port]);
741 		if (retval < 0)
742 			goto error;
743 	}
744 
745 	return retval;
746 
747 error:
748 	dev_err(&dev->dev,
749 		"Error setting up SB800 adapters. Unregistering!\n");
750 	while (--port >= 0) {
751 		adapdata = i2c_get_adapdata(piix4_main_adapters[port]);
752 		if (adapdata->smba) {
753 			i2c_del_adapter(piix4_main_adapters[port]);
754 			kfree(adapdata);
755 			kfree(piix4_main_adapters[port]);
756 			piix4_main_adapters[port] = NULL;
757 		}
758 	}
759 
760 	return retval;
761 }
762 
763 static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
764 {
765 	int retval;
766 	bool is_sb800 = false;
767 
768 	if ((dev->vendor == PCI_VENDOR_ID_ATI &&
769 	     dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
770 	     dev->revision >= 0x40) ||
771 	    dev->vendor == PCI_VENDOR_ID_AMD) {
772 		is_sb800 = true;
773 
774 		if (!request_region(SB800_PIIX4_SMB_IDX, 2, "smba_idx")) {
775 			dev_err(&dev->dev,
776 			"SMBus base address index region 0x%x already in use!\n",
777 			SB800_PIIX4_SMB_IDX);
778 			return -EBUSY;
779 		}
780 
781 		/* base address location etc changed in SB800 */
782 		retval = piix4_setup_sb800(dev, id, 0);
783 		if (retval < 0) {
784 			release_region(SB800_PIIX4_SMB_IDX, 2);
785 			return retval;
786 		}
787 
788 		/*
789 		 * Try to register multiplexed main SMBus adapter,
790 		 * give up if we can't
791 		 */
792 		retval = piix4_add_adapters_sb800(dev, retval);
793 		if (retval < 0) {
794 			release_region(SB800_PIIX4_SMB_IDX, 2);
795 			return retval;
796 		}
797 	} else {
798 		retval = piix4_setup(dev, id);
799 		if (retval < 0)
800 			return retval;
801 
802 		/* Try to register main SMBus adapter, give up if we can't */
803 		retval = piix4_add_adapter(dev, retval, false, 0, "",
804 					   &piix4_main_adapters[0]);
805 		if (retval < 0)
806 			return retval;
807 	}
808 
809 	/* Check for auxiliary SMBus on some AMD chipsets */
810 	retval = -ENODEV;
811 
812 	if (dev->vendor == PCI_VENDOR_ID_ATI &&
813 	    dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS) {
814 		if (dev->revision < 0x40) {
815 			retval = piix4_setup_aux(dev, id, 0x58);
816 		} else {
817 			/* SB800 added aux bus too */
818 			retval = piix4_setup_sb800(dev, id, 1);
819 		}
820 	}
821 
822 	if (dev->vendor == PCI_VENDOR_ID_AMD &&
823 	    dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) {
824 		retval = piix4_setup_sb800(dev, id, 1);
825 	}
826 
827 	if (retval > 0) {
828 		/* Try to add the aux adapter if it exists,
829 		 * piix4_add_adapter will clean up if this fails */
830 		piix4_add_adapter(dev, retval, false, 0,
831 				  is_sb800 ? piix4_aux_port_name_sb800 : "",
832 				  &piix4_aux_adapter);
833 	}
834 
835 	return 0;
836 }
837 
838 static void piix4_adap_remove(struct i2c_adapter *adap)
839 {
840 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
841 
842 	if (adapdata->smba) {
843 		i2c_del_adapter(adap);
844 		if (adapdata->port == (0 << 1)) {
845 			release_region(adapdata->smba, SMBIOSIZE);
846 			if (adapdata->sb800_main)
847 				release_region(SB800_PIIX4_SMB_IDX, 2);
848 		}
849 		kfree(adapdata);
850 		kfree(adap);
851 	}
852 }
853 
854 static void piix4_remove(struct pci_dev *dev)
855 {
856 	int port = PIIX4_MAX_ADAPTERS;
857 
858 	while (--port >= 0) {
859 		if (piix4_main_adapters[port]) {
860 			piix4_adap_remove(piix4_main_adapters[port]);
861 			piix4_main_adapters[port] = NULL;
862 		}
863 	}
864 
865 	if (piix4_aux_adapter) {
866 		piix4_adap_remove(piix4_aux_adapter);
867 		piix4_aux_adapter = NULL;
868 	}
869 }
870 
871 static struct pci_driver piix4_driver = {
872 	.name		= "piix4_smbus",
873 	.id_table	= piix4_ids,
874 	.probe		= piix4_probe,
875 	.remove		= piix4_remove,
876 };
877 
878 module_pci_driver(piix4_driver);
879 
880 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
881 		"Philip Edelbrock <phil@netroedge.com>");
882 MODULE_DESCRIPTION("PIIX4 SMBus driver");
883 MODULE_LICENSE("GPL");
884