xref: /linux/drivers/i2c/busses/i2c-piix4.c (revision 48c7d73b2362ce61503551ad70052617b3e8857d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3     Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl> and
4     Philip Edelbrock <phil@netroedge.com>
5 
6 */
7 
8 /*
9    Supports:
10 	Intel PIIX4, 440MX
11 	Serverworks OSB4, CSB5, CSB6, HT-1000, HT-1100
12 	ATI IXP200, IXP300, IXP400, SB600, SB700/SP5100, SB800
13 	AMD Hudson-2, ML, CZ
14 	Hygon CZ
15 	SMSC Victory66
16 
17    Note: we assume there can only be one device, with one or more
18    SMBus interfaces.
19    The device can register multiple i2c_adapters (up to PIIX4_MAX_ADAPTERS).
20    For devices supporting multiple ports the i2c_adapter should provide
21    an i2c_algorithm to access them.
22 */
23 
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/pci.h>
27 #include <linux/kernel.h>
28 #include <linux/delay.h>
29 #include <linux/stddef.h>
30 #include <linux/ioport.h>
31 #include <linux/i2c.h>
32 #include <linux/slab.h>
33 #include <linux/dmi.h>
34 #include <linux/acpi.h>
35 #include <linux/io.h>
36 
37 
38 /* PIIX4 SMBus address offsets */
39 #define SMBHSTSTS	(0 + piix4_smba)
40 #define SMBHSLVSTS	(1 + piix4_smba)
41 #define SMBHSTCNT	(2 + piix4_smba)
42 #define SMBHSTCMD	(3 + piix4_smba)
43 #define SMBHSTADD	(4 + piix4_smba)
44 #define SMBHSTDAT0	(5 + piix4_smba)
45 #define SMBHSTDAT1	(6 + piix4_smba)
46 #define SMBBLKDAT	(7 + piix4_smba)
47 #define SMBSLVCNT	(8 + piix4_smba)
48 #define SMBSHDWCMD	(9 + piix4_smba)
49 #define SMBSLVEVT	(0xA + piix4_smba)
50 #define SMBSLVDAT	(0xC + piix4_smba)
51 
52 /* count for request_region */
53 #define SMBIOSIZE	9
54 
55 /* PCI Address Constants */
56 #define SMBBA		0x090
57 #define SMBHSTCFG	0x0D2
58 #define SMBSLVC		0x0D3
59 #define SMBSHDW1	0x0D4
60 #define SMBSHDW2	0x0D5
61 #define SMBREV		0x0D6
62 
63 /* Other settings */
64 #define MAX_TIMEOUT	500
65 #define  ENABLE_INT9	0
66 
67 /* PIIX4 constants */
68 #define PIIX4_QUICK		0x00
69 #define PIIX4_BYTE		0x04
70 #define PIIX4_BYTE_DATA		0x08
71 #define PIIX4_WORD_DATA		0x0C
72 #define PIIX4_BLOCK_DATA	0x14
73 
74 /* Multi-port constants */
75 #define PIIX4_MAX_ADAPTERS 4
76 
77 /* SB800 constants */
78 #define SB800_PIIX4_SMB_IDX		0xcd6
79 
80 #define KERNCZ_IMC_IDX			0x3e
81 #define KERNCZ_IMC_DATA			0x3f
82 
83 /*
84  * SB800 port is selected by bits 2:1 of the smb_en register (0x2c)
85  * or the smb_sel register (0x2e), depending on bit 0 of register 0x2f.
86  * Hudson-2/Bolton port is always selected by bits 2:1 of register 0x2f.
87  */
88 #define SB800_PIIX4_PORT_IDX		0x2c
89 #define SB800_PIIX4_PORT_IDX_ALT	0x2e
90 #define SB800_PIIX4_PORT_IDX_SEL	0x2f
91 #define SB800_PIIX4_PORT_IDX_MASK	0x06
92 #define SB800_PIIX4_PORT_IDX_SHIFT	1
93 
94 /* On kerncz, SmBus0Sel is at bit 20:19 of PMx00 DecodeEn */
95 #define SB800_PIIX4_PORT_IDX_KERNCZ		0x02
96 #define SB800_PIIX4_PORT_IDX_MASK_KERNCZ	0x18
97 #define SB800_PIIX4_PORT_IDX_SHIFT_KERNCZ	3
98 
99 /* insmod parameters */
100 
101 /* If force is set to anything different from 0, we forcibly enable the
102    PIIX4. DANGEROUS! */
103 static int force;
104 module_param (force, int, 0);
105 MODULE_PARM_DESC(force, "Forcibly enable the PIIX4. DANGEROUS!");
106 
107 /* If force_addr is set to anything different from 0, we forcibly enable
108    the PIIX4 at the given address. VERY DANGEROUS! */
109 static int force_addr;
110 module_param_hw(force_addr, int, ioport, 0);
111 MODULE_PARM_DESC(force_addr,
112 		 "Forcibly enable the PIIX4 at the given address. "
113 		 "EXTREMELY DANGEROUS!");
114 
115 static int srvrworks_csb5_delay;
116 static struct pci_driver piix4_driver;
117 
118 static const struct dmi_system_id piix4_dmi_blacklist[] = {
119 	{
120 		.ident = "Sapphire AM2RD790",
121 		.matches = {
122 			DMI_MATCH(DMI_BOARD_VENDOR, "SAPPHIRE Inc."),
123 			DMI_MATCH(DMI_BOARD_NAME, "PC-AM2RD790"),
124 		},
125 	},
126 	{
127 		.ident = "DFI Lanparty UT 790FX",
128 		.matches = {
129 			DMI_MATCH(DMI_BOARD_VENDOR, "DFI Inc."),
130 			DMI_MATCH(DMI_BOARD_NAME, "LP UT 790FX"),
131 		},
132 	},
133 	{ }
134 };
135 
136 /* The IBM entry is in a separate table because we only check it
137    on Intel-based systems */
138 static const struct dmi_system_id piix4_dmi_ibm[] = {
139 	{
140 		.ident = "IBM",
141 		.matches = { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
142 	},
143 	{ },
144 };
145 
146 /*
147  * SB800 globals
148  */
149 static u8 piix4_port_sel_sb800;
150 static u8 piix4_port_mask_sb800;
151 static u8 piix4_port_shift_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 	bool notify_imc;
163 	u8 port;		/* Port number, shifted */
164 };
165 
166 static int piix4_setup(struct pci_dev *PIIX4_dev,
167 		       const struct pci_device_id *id)
168 {
169 	unsigned char temp;
170 	unsigned short piix4_smba;
171 
172 	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_SERVERWORKS) &&
173 	    (PIIX4_dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB5))
174 		srvrworks_csb5_delay = 1;
175 
176 	/* On some motherboards, it was reported that accessing the SMBus
177 	   caused severe hardware problems */
178 	if (dmi_check_system(piix4_dmi_blacklist)) {
179 		dev_err(&PIIX4_dev->dev,
180 			"Accessing the SMBus on this system is unsafe!\n");
181 		return -EPERM;
182 	}
183 
184 	/* Don't access SMBus on IBM systems which get corrupted eeproms */
185 	if (dmi_check_system(piix4_dmi_ibm) &&
186 			PIIX4_dev->vendor == PCI_VENDOR_ID_INTEL) {
187 		dev_err(&PIIX4_dev->dev, "IBM system detected; this module "
188 			"may corrupt your serial eeprom! Refusing to load "
189 			"module!\n");
190 		return -EPERM;
191 	}
192 
193 	/* Determine the address of the SMBus areas */
194 	if (force_addr) {
195 		piix4_smba = force_addr & 0xfff0;
196 		force = 0;
197 	} else {
198 		pci_read_config_word(PIIX4_dev, SMBBA, &piix4_smba);
199 		piix4_smba &= 0xfff0;
200 		if(piix4_smba == 0) {
201 			dev_err(&PIIX4_dev->dev, "SMBus base address "
202 				"uninitialized - upgrade BIOS or use "
203 				"force_addr=0xaddr\n");
204 			return -ENODEV;
205 		}
206 	}
207 
208 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
209 		return -ENODEV;
210 
211 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
212 		dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
213 			piix4_smba);
214 		return -EBUSY;
215 	}
216 
217 	pci_read_config_byte(PIIX4_dev, SMBHSTCFG, &temp);
218 
219 	/* If force_addr is set, we program the new address here. Just to make
220 	   sure, we disable the PIIX4 first. */
221 	if (force_addr) {
222 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp & 0xfe);
223 		pci_write_config_word(PIIX4_dev, SMBBA, piix4_smba);
224 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp | 0x01);
225 		dev_info(&PIIX4_dev->dev, "WARNING: SMBus interface set to "
226 			"new address %04x!\n", piix4_smba);
227 	} else if ((temp & 1) == 0) {
228 		if (force) {
229 			/* This should never need to be done, but has been
230 			 * noted that many Dell machines have the SMBus
231 			 * interface on the PIIX4 disabled!? NOTE: This assumes
232 			 * I/O space and other allocations WERE done by the
233 			 * Bios!  Don't complain if your hardware does weird
234 			 * things after enabling this. :') Check for Bios
235 			 * updates before resorting to this.
236 			 */
237 			pci_write_config_byte(PIIX4_dev, SMBHSTCFG,
238 					      temp | 1);
239 			dev_notice(&PIIX4_dev->dev,
240 				   "WARNING: SMBus interface has been FORCEFULLY ENABLED!\n");
241 		} else {
242 			dev_err(&PIIX4_dev->dev,
243 				"SMBus Host Controller not enabled!\n");
244 			release_region(piix4_smba, SMBIOSIZE);
245 			return -ENODEV;
246 		}
247 	}
248 
249 	if (((temp & 0x0E) == 8) || ((temp & 0x0E) == 2))
250 		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
251 	else if ((temp & 0x0E) == 0)
252 		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");
253 	else
254 		dev_err(&PIIX4_dev->dev, "Illegal Interrupt configuration "
255 			"(or code out of date)!\n");
256 
257 	pci_read_config_byte(PIIX4_dev, SMBREV, &temp);
258 	dev_info(&PIIX4_dev->dev,
259 		 "SMBus Host Controller at 0x%x, revision %d\n",
260 		 piix4_smba, temp);
261 
262 	return piix4_smba;
263 }
264 
265 static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
266 			     const struct pci_device_id *id, u8 aux)
267 {
268 	unsigned short piix4_smba;
269 	u8 smba_en_lo, smba_en_hi, smb_en, smb_en_status, port_sel;
270 	u8 i2ccfg, i2ccfg_offset = 0x10;
271 
272 	/* SB800 and later SMBus does not support forcing address */
273 	if (force || force_addr) {
274 		dev_err(&PIIX4_dev->dev, "SMBus does not support "
275 			"forcing address!\n");
276 		return -EINVAL;
277 	}
278 
279 	/* Determine the address of the SMBus areas */
280 	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
281 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
282 	     PIIX4_dev->revision >= 0x41) ||
283 	    (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
284 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
285 	     PIIX4_dev->revision >= 0x49) ||
286 	    (PIIX4_dev->vendor == PCI_VENDOR_ID_HYGON &&
287 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS))
288 		smb_en = 0x00;
289 	else
290 		smb_en = (aux) ? 0x28 : 0x2c;
291 
292 	if (!request_muxed_region(SB800_PIIX4_SMB_IDX, 2, "sb800_piix4_smb")) {
293 		dev_err(&PIIX4_dev->dev,
294 			"SMB base address index region 0x%x already in use.\n",
295 			SB800_PIIX4_SMB_IDX);
296 		return -EBUSY;
297 	}
298 
299 	outb_p(smb_en, SB800_PIIX4_SMB_IDX);
300 	smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
301 	outb_p(smb_en + 1, SB800_PIIX4_SMB_IDX);
302 	smba_en_hi = inb_p(SB800_PIIX4_SMB_IDX + 1);
303 
304 	release_region(SB800_PIIX4_SMB_IDX, 2);
305 
306 	if (!smb_en) {
307 		smb_en_status = smba_en_lo & 0x10;
308 		piix4_smba = smba_en_hi << 8;
309 		if (aux)
310 			piix4_smba |= 0x20;
311 	} else {
312 		smb_en_status = smba_en_lo & 0x01;
313 		piix4_smba = ((smba_en_hi << 8) | smba_en_lo) & 0xffe0;
314 	}
315 
316 	if (!smb_en_status) {
317 		dev_err(&PIIX4_dev->dev,
318 			"SMBus Host Controller not enabled!\n");
319 		return -ENODEV;
320 	}
321 
322 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
323 		return -ENODEV;
324 
325 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
326 		dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
327 			piix4_smba);
328 		return -EBUSY;
329 	}
330 
331 	/* Aux SMBus does not support IRQ information */
332 	if (aux) {
333 		dev_info(&PIIX4_dev->dev,
334 			 "Auxiliary SMBus Host Controller at 0x%x\n",
335 			 piix4_smba);
336 		return piix4_smba;
337 	}
338 
339 	/* Request the SMBus I2C bus config region */
340 	if (!request_region(piix4_smba + i2ccfg_offset, 1, "i2ccfg")) {
341 		dev_err(&PIIX4_dev->dev, "SMBus I2C bus config region "
342 			"0x%x already in use!\n", piix4_smba + i2ccfg_offset);
343 		release_region(piix4_smba, SMBIOSIZE);
344 		return -EBUSY;
345 	}
346 	i2ccfg = inb_p(piix4_smba + i2ccfg_offset);
347 	release_region(piix4_smba + i2ccfg_offset, 1);
348 
349 	if (i2ccfg & 1)
350 		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
351 	else
352 		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");
353 
354 	dev_info(&PIIX4_dev->dev,
355 		 "SMBus Host Controller at 0x%x, revision %d\n",
356 		 piix4_smba, i2ccfg >> 4);
357 
358 	/* Find which register is used for port selection */
359 	if (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD ||
360 	    PIIX4_dev->vendor == PCI_VENDOR_ID_HYGON) {
361 		switch (PIIX4_dev->device) {
362 		case PCI_DEVICE_ID_AMD_KERNCZ_SMBUS:
363 			piix4_port_sel_sb800 = SB800_PIIX4_PORT_IDX_KERNCZ;
364 			piix4_port_mask_sb800 = SB800_PIIX4_PORT_IDX_MASK_KERNCZ;
365 			piix4_port_shift_sb800 = SB800_PIIX4_PORT_IDX_SHIFT_KERNCZ;
366 			break;
367 		case PCI_DEVICE_ID_AMD_HUDSON2_SMBUS:
368 		default:
369 			piix4_port_sel_sb800 = SB800_PIIX4_PORT_IDX_ALT;
370 			piix4_port_mask_sb800 = SB800_PIIX4_PORT_IDX_MASK;
371 			piix4_port_shift_sb800 = SB800_PIIX4_PORT_IDX_SHIFT;
372 			break;
373 		}
374 	} else {
375 		if (!request_muxed_region(SB800_PIIX4_SMB_IDX, 2,
376 					  "sb800_piix4_smb")) {
377 			release_region(piix4_smba, SMBIOSIZE);
378 			return -EBUSY;
379 		}
380 
381 		outb_p(SB800_PIIX4_PORT_IDX_SEL, SB800_PIIX4_SMB_IDX);
382 		port_sel = inb_p(SB800_PIIX4_SMB_IDX + 1);
383 		piix4_port_sel_sb800 = (port_sel & 0x01) ?
384 				       SB800_PIIX4_PORT_IDX_ALT :
385 				       SB800_PIIX4_PORT_IDX;
386 		piix4_port_mask_sb800 = SB800_PIIX4_PORT_IDX_MASK;
387 		piix4_port_shift_sb800 = SB800_PIIX4_PORT_IDX_SHIFT;
388 		release_region(SB800_PIIX4_SMB_IDX, 2);
389 	}
390 
391 	dev_info(&PIIX4_dev->dev,
392 		 "Using register 0x%02x for SMBus port selection\n",
393 		 (unsigned int)piix4_port_sel_sb800);
394 
395 	return piix4_smba;
396 }
397 
398 static int piix4_setup_aux(struct pci_dev *PIIX4_dev,
399 			   const struct pci_device_id *id,
400 			   unsigned short base_reg_addr)
401 {
402 	/* Set up auxiliary SMBus controllers found on some
403 	 * AMD chipsets e.g. SP5100 (SB700 derivative) */
404 
405 	unsigned short piix4_smba;
406 
407 	/* Read address of auxiliary SMBus controller */
408 	pci_read_config_word(PIIX4_dev, base_reg_addr, &piix4_smba);
409 	if ((piix4_smba & 1) == 0) {
410 		dev_dbg(&PIIX4_dev->dev,
411 			"Auxiliary SMBus controller not enabled\n");
412 		return -ENODEV;
413 	}
414 
415 	piix4_smba &= 0xfff0;
416 	if (piix4_smba == 0) {
417 		dev_dbg(&PIIX4_dev->dev,
418 			"Auxiliary SMBus base address uninitialized\n");
419 		return -ENODEV;
420 	}
421 
422 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
423 		return -ENODEV;
424 
425 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
426 		dev_err(&PIIX4_dev->dev, "Auxiliary SMBus region 0x%x "
427 			"already in use!\n", piix4_smba);
428 		return -EBUSY;
429 	}
430 
431 	dev_info(&PIIX4_dev->dev,
432 		 "Auxiliary SMBus Host Controller at 0x%x\n",
433 		 piix4_smba);
434 
435 	return piix4_smba;
436 }
437 
438 static int piix4_transaction(struct i2c_adapter *piix4_adapter)
439 {
440 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(piix4_adapter);
441 	unsigned short piix4_smba = adapdata->smba;
442 	int temp;
443 	int result = 0;
444 	int timeout = 0;
445 
446 	dev_dbg(&piix4_adapter->dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
447 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
448 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
449 		inb_p(SMBHSTDAT1));
450 
451 	/* Make sure the SMBus host is ready to start transmitting */
452 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
453 		dev_dbg(&piix4_adapter->dev, "SMBus busy (%02x). "
454 			"Resetting...\n", temp);
455 		outb_p(temp, SMBHSTSTS);
456 		if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
457 			dev_err(&piix4_adapter->dev, "Failed! (%02x)\n", temp);
458 			return -EBUSY;
459 		} else {
460 			dev_dbg(&piix4_adapter->dev, "Successful!\n");
461 		}
462 	}
463 
464 	/* start the transaction by setting bit 6 */
465 	outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);
466 
467 	/* We will always wait for a fraction of a second! (See PIIX4 docs errata) */
468 	if (srvrworks_csb5_delay) /* Extra delay for SERVERWORKS_CSB5 */
469 		usleep_range(2000, 2100);
470 	else
471 		usleep_range(250, 500);
472 
473 	while ((++timeout < MAX_TIMEOUT) &&
474 	       ((temp = inb_p(SMBHSTSTS)) & 0x01))
475 		usleep_range(250, 500);
476 
477 	/* If the SMBus is still busy, we give up */
478 	if (timeout == MAX_TIMEOUT) {
479 		dev_err(&piix4_adapter->dev, "SMBus Timeout!\n");
480 		result = -ETIMEDOUT;
481 	}
482 
483 	if (temp & 0x10) {
484 		result = -EIO;
485 		dev_err(&piix4_adapter->dev, "Error: Failed bus transaction\n");
486 	}
487 
488 	if (temp & 0x08) {
489 		result = -EIO;
490 		dev_dbg(&piix4_adapter->dev, "Bus collision! SMBus may be "
491 			"locked until next hard reset. (sorry!)\n");
492 		/* Clock stops and slave is stuck in mid-transmission */
493 	}
494 
495 	if (temp & 0x04) {
496 		result = -ENXIO;
497 		dev_dbg(&piix4_adapter->dev, "Error: no response!\n");
498 	}
499 
500 	if (inb_p(SMBHSTSTS) != 0x00)
501 		outb_p(inb(SMBHSTSTS), SMBHSTSTS);
502 
503 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
504 		dev_err(&piix4_adapter->dev, "Failed reset at end of "
505 			"transaction (%02x)\n", temp);
506 	}
507 	dev_dbg(&piix4_adapter->dev, "Transaction (post): CNT=%02x, CMD=%02x, "
508 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
509 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
510 		inb_p(SMBHSTDAT1));
511 	return result;
512 }
513 
514 /* Return negative errno on error. */
515 static s32 piix4_access(struct i2c_adapter * adap, u16 addr,
516 		 unsigned short flags, char read_write,
517 		 u8 command, int size, union i2c_smbus_data * data)
518 {
519 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
520 	unsigned short piix4_smba = adapdata->smba;
521 	int i, len;
522 	int status;
523 
524 	switch (size) {
525 	case I2C_SMBUS_QUICK:
526 		outb_p((addr << 1) | read_write,
527 		       SMBHSTADD);
528 		size = PIIX4_QUICK;
529 		break;
530 	case I2C_SMBUS_BYTE:
531 		outb_p((addr << 1) | read_write,
532 		       SMBHSTADD);
533 		if (read_write == I2C_SMBUS_WRITE)
534 			outb_p(command, SMBHSTCMD);
535 		size = PIIX4_BYTE;
536 		break;
537 	case I2C_SMBUS_BYTE_DATA:
538 		outb_p((addr << 1) | read_write,
539 		       SMBHSTADD);
540 		outb_p(command, SMBHSTCMD);
541 		if (read_write == I2C_SMBUS_WRITE)
542 			outb_p(data->byte, SMBHSTDAT0);
543 		size = PIIX4_BYTE_DATA;
544 		break;
545 	case I2C_SMBUS_WORD_DATA:
546 		outb_p((addr << 1) | read_write,
547 		       SMBHSTADD);
548 		outb_p(command, SMBHSTCMD);
549 		if (read_write == I2C_SMBUS_WRITE) {
550 			outb_p(data->word & 0xff, SMBHSTDAT0);
551 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
552 		}
553 		size = PIIX4_WORD_DATA;
554 		break;
555 	case I2C_SMBUS_BLOCK_DATA:
556 		outb_p((addr << 1) | read_write,
557 		       SMBHSTADD);
558 		outb_p(command, SMBHSTCMD);
559 		if (read_write == I2C_SMBUS_WRITE) {
560 			len = data->block[0];
561 			if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
562 				return -EINVAL;
563 			outb_p(len, SMBHSTDAT0);
564 			inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
565 			for (i = 1; i <= len; i++)
566 				outb_p(data->block[i], SMBBLKDAT);
567 		}
568 		size = PIIX4_BLOCK_DATA;
569 		break;
570 	default:
571 		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
572 		return -EOPNOTSUPP;
573 	}
574 
575 	outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);
576 
577 	status = piix4_transaction(adap);
578 	if (status)
579 		return status;
580 
581 	if ((read_write == I2C_SMBUS_WRITE) || (size == PIIX4_QUICK))
582 		return 0;
583 
584 
585 	switch (size) {
586 	case PIIX4_BYTE:
587 	case PIIX4_BYTE_DATA:
588 		data->byte = inb_p(SMBHSTDAT0);
589 		break;
590 	case PIIX4_WORD_DATA:
591 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
592 		break;
593 	case PIIX4_BLOCK_DATA:
594 		data->block[0] = inb_p(SMBHSTDAT0);
595 		if (data->block[0] == 0 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
596 			return -EPROTO;
597 		inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
598 		for (i = 1; i <= data->block[0]; i++)
599 			data->block[i] = inb_p(SMBBLKDAT);
600 		break;
601 	}
602 	return 0;
603 }
604 
605 static uint8_t piix4_imc_read(uint8_t idx)
606 {
607 	outb_p(idx, KERNCZ_IMC_IDX);
608 	return inb_p(KERNCZ_IMC_DATA);
609 }
610 
611 static void piix4_imc_write(uint8_t idx, uint8_t value)
612 {
613 	outb_p(idx, KERNCZ_IMC_IDX);
614 	outb_p(value, KERNCZ_IMC_DATA);
615 }
616 
617 static int piix4_imc_sleep(void)
618 {
619 	int timeout = MAX_TIMEOUT;
620 
621 	if (!request_muxed_region(KERNCZ_IMC_IDX, 2, "smbus_kerncz_imc"))
622 		return -EBUSY;
623 
624 	/* clear response register */
625 	piix4_imc_write(0x82, 0x00);
626 	/* request ownership flag */
627 	piix4_imc_write(0x83, 0xB4);
628 	/* kick off IMC Mailbox command 96 */
629 	piix4_imc_write(0x80, 0x96);
630 
631 	while (timeout--) {
632 		if (piix4_imc_read(0x82) == 0xfa) {
633 			release_region(KERNCZ_IMC_IDX, 2);
634 			return 0;
635 		}
636 		usleep_range(1000, 2000);
637 	}
638 
639 	release_region(KERNCZ_IMC_IDX, 2);
640 	return -ETIMEDOUT;
641 }
642 
643 static void piix4_imc_wakeup(void)
644 {
645 	int timeout = MAX_TIMEOUT;
646 
647 	if (!request_muxed_region(KERNCZ_IMC_IDX, 2, "smbus_kerncz_imc"))
648 		return;
649 
650 	/* clear response register */
651 	piix4_imc_write(0x82, 0x00);
652 	/* release ownership flag */
653 	piix4_imc_write(0x83, 0xB5);
654 	/* kick off IMC Mailbox command 96 */
655 	piix4_imc_write(0x80, 0x96);
656 
657 	while (timeout--) {
658 		if (piix4_imc_read(0x82) == 0xfa)
659 			break;
660 		usleep_range(1000, 2000);
661 	}
662 
663 	release_region(KERNCZ_IMC_IDX, 2);
664 }
665 
666 /*
667  * Handles access to multiple SMBus ports on the SB800.
668  * The port is selected by bits 2:1 of the smb_en register (0x2c).
669  * Returns negative errno on error.
670  *
671  * Note: The selected port must be returned to the initial selection to avoid
672  * problems on certain systems.
673  */
674 static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
675 		 unsigned short flags, char read_write,
676 		 u8 command, int size, union i2c_smbus_data *data)
677 {
678 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
679 	unsigned short piix4_smba = adapdata->smba;
680 	int retries = MAX_TIMEOUT;
681 	int smbslvcnt;
682 	u8 smba_en_lo;
683 	u8 port;
684 	int retval;
685 
686 	if (!request_muxed_region(SB800_PIIX4_SMB_IDX, 2, "sb800_piix4_smb"))
687 		return -EBUSY;
688 
689 	/* Request the SMBUS semaphore, avoid conflicts with the IMC */
690 	smbslvcnt  = inb_p(SMBSLVCNT);
691 	do {
692 		outb_p(smbslvcnt | 0x10, SMBSLVCNT);
693 
694 		/* Check the semaphore status */
695 		smbslvcnt  = inb_p(SMBSLVCNT);
696 		if (smbslvcnt & 0x10)
697 			break;
698 
699 		usleep_range(1000, 2000);
700 	} while (--retries);
701 	/* SMBus is still owned by the IMC, we give up */
702 	if (!retries) {
703 		retval = -EBUSY;
704 		goto release;
705 	}
706 
707 	/*
708 	 * Notify the IMC (Integrated Micro Controller) if required.
709 	 * Among other responsibilities, the IMC is in charge of monitoring
710 	 * the System fans and temperature sensors, and act accordingly.
711 	 * All this is done through SMBus and can/will collide
712 	 * with our transactions if they are long (BLOCK_DATA).
713 	 * Therefore we need to request the ownership flag during those
714 	 * transactions.
715 	 */
716 	if ((size == I2C_SMBUS_BLOCK_DATA) && adapdata->notify_imc) {
717 		int ret;
718 
719 		ret = piix4_imc_sleep();
720 		switch (ret) {
721 		case -EBUSY:
722 			dev_warn(&adap->dev,
723 				 "IMC base address index region 0x%x already in use.\n",
724 				 KERNCZ_IMC_IDX);
725 			break;
726 		case -ETIMEDOUT:
727 			dev_warn(&adap->dev,
728 				 "Failed to communicate with the IMC.\n");
729 			break;
730 		default:
731 			break;
732 		}
733 
734 		/* If IMC communication fails do not retry */
735 		if (ret) {
736 			dev_warn(&adap->dev,
737 				 "Continuing without IMC notification.\n");
738 			adapdata->notify_imc = false;
739 		}
740 	}
741 
742 	outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX);
743 	smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
744 
745 	port = adapdata->port;
746 	if ((smba_en_lo & piix4_port_mask_sb800) != port)
747 		outb_p((smba_en_lo & ~piix4_port_mask_sb800) | port,
748 		       SB800_PIIX4_SMB_IDX + 1);
749 
750 	retval = piix4_access(adap, addr, flags, read_write,
751 			      command, size, data);
752 
753 	outb_p(smba_en_lo, SB800_PIIX4_SMB_IDX + 1);
754 
755 	/* Release the semaphore */
756 	outb_p(smbslvcnt | 0x20, SMBSLVCNT);
757 
758 	if ((size == I2C_SMBUS_BLOCK_DATA) && adapdata->notify_imc)
759 		piix4_imc_wakeup();
760 
761 release:
762 	release_region(SB800_PIIX4_SMB_IDX, 2);
763 	return retval;
764 }
765 
766 static u32 piix4_func(struct i2c_adapter *adapter)
767 {
768 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
769 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
770 	    I2C_FUNC_SMBUS_BLOCK_DATA;
771 }
772 
773 static const struct i2c_algorithm smbus_algorithm = {
774 	.smbus_xfer	= piix4_access,
775 	.functionality	= piix4_func,
776 };
777 
778 static const struct i2c_algorithm piix4_smbus_algorithm_sb800 = {
779 	.smbus_xfer	= piix4_access_sb800,
780 	.functionality	= piix4_func,
781 };
782 
783 static const struct pci_device_id piix4_ids[] = {
784 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
785 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3) },
786 	{ PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_SLC90E66_3) },
787 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP200_SMBUS) },
788 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP300_SMBUS) },
789 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS) },
790 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS) },
791 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) },
792 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) },
793 	{ PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) },
794 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
795 		     PCI_DEVICE_ID_SERVERWORKS_OSB4) },
796 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
797 		     PCI_DEVICE_ID_SERVERWORKS_CSB5) },
798 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
799 		     PCI_DEVICE_ID_SERVERWORKS_CSB6) },
800 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
801 		     PCI_DEVICE_ID_SERVERWORKS_HT1000SB) },
802 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
803 		     PCI_DEVICE_ID_SERVERWORKS_HT1100LD) },
804 	{ 0, }
805 };
806 
807 MODULE_DEVICE_TABLE (pci, piix4_ids);
808 
809 static struct i2c_adapter *piix4_main_adapters[PIIX4_MAX_ADAPTERS];
810 static struct i2c_adapter *piix4_aux_adapter;
811 
812 static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
813 			     bool sb800_main, u8 port, bool notify_imc,
814 			     const char *name, struct i2c_adapter **padap)
815 {
816 	struct i2c_adapter *adap;
817 	struct i2c_piix4_adapdata *adapdata;
818 	int retval;
819 
820 	adap = kzalloc(sizeof(*adap), GFP_KERNEL);
821 	if (adap == NULL) {
822 		release_region(smba, SMBIOSIZE);
823 		return -ENOMEM;
824 	}
825 
826 	adap->owner = THIS_MODULE;
827 	adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
828 	adap->algo = sb800_main ? &piix4_smbus_algorithm_sb800
829 				: &smbus_algorithm;
830 
831 	adapdata = kzalloc(sizeof(*adapdata), GFP_KERNEL);
832 	if (adapdata == NULL) {
833 		kfree(adap);
834 		release_region(smba, SMBIOSIZE);
835 		return -ENOMEM;
836 	}
837 
838 	adapdata->smba = smba;
839 	adapdata->sb800_main = sb800_main;
840 	adapdata->port = port << piix4_port_shift_sb800;
841 	adapdata->notify_imc = notify_imc;
842 
843 	/* set up the sysfs linkage to our parent device */
844 	adap->dev.parent = &dev->dev;
845 
846 	snprintf(adap->name, sizeof(adap->name),
847 		"SMBus PIIX4 adapter%s at %04x", name, smba);
848 
849 	i2c_set_adapdata(adap, adapdata);
850 
851 	retval = i2c_add_adapter(adap);
852 	if (retval) {
853 		kfree(adapdata);
854 		kfree(adap);
855 		release_region(smba, SMBIOSIZE);
856 		return retval;
857 	}
858 
859 	*padap = adap;
860 	return 0;
861 }
862 
863 static int piix4_add_adapters_sb800(struct pci_dev *dev, unsigned short smba,
864 				    bool notify_imc)
865 {
866 	struct i2c_piix4_adapdata *adapdata;
867 	int port;
868 	int retval;
869 
870 	for (port = 0; port < PIIX4_MAX_ADAPTERS; port++) {
871 		retval = piix4_add_adapter(dev, smba, true, port, notify_imc,
872 					   piix4_main_port_names_sb800[port],
873 					   &piix4_main_adapters[port]);
874 		if (retval < 0)
875 			goto error;
876 	}
877 
878 	return retval;
879 
880 error:
881 	dev_err(&dev->dev,
882 		"Error setting up SB800 adapters. Unregistering!\n");
883 	while (--port >= 0) {
884 		adapdata = i2c_get_adapdata(piix4_main_adapters[port]);
885 		if (adapdata->smba) {
886 			i2c_del_adapter(piix4_main_adapters[port]);
887 			kfree(adapdata);
888 			kfree(piix4_main_adapters[port]);
889 			piix4_main_adapters[port] = NULL;
890 		}
891 	}
892 
893 	return retval;
894 }
895 
896 static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
897 {
898 	int retval;
899 	bool is_sb800 = false;
900 
901 	if ((dev->vendor == PCI_VENDOR_ID_ATI &&
902 	     dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
903 	     dev->revision >= 0x40) ||
904 	    dev->vendor == PCI_VENDOR_ID_AMD ||
905 	    dev->vendor == PCI_VENDOR_ID_HYGON) {
906 		bool notify_imc = false;
907 		is_sb800 = true;
908 
909 		if ((dev->vendor == PCI_VENDOR_ID_AMD ||
910 		     dev->vendor == PCI_VENDOR_ID_HYGON) &&
911 		    dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) {
912 			u8 imc;
913 
914 			/*
915 			 * Detect if IMC is active or not, this method is
916 			 * described on coreboot's AMD IMC notes
917 			 */
918 			pci_bus_read_config_byte(dev->bus, PCI_DEVFN(0x14, 3),
919 						 0x40, &imc);
920 			if (imc & 0x80)
921 				notify_imc = true;
922 		}
923 
924 		/* base address location etc changed in SB800 */
925 		retval = piix4_setup_sb800(dev, id, 0);
926 		if (retval < 0)
927 			return retval;
928 
929 		/*
930 		 * Try to register multiplexed main SMBus adapter,
931 		 * give up if we can't
932 		 */
933 		retval = piix4_add_adapters_sb800(dev, retval, notify_imc);
934 		if (retval < 0)
935 			return retval;
936 	} else {
937 		retval = piix4_setup(dev, id);
938 		if (retval < 0)
939 			return retval;
940 
941 		/* Try to register main SMBus adapter, give up if we can't */
942 		retval = piix4_add_adapter(dev, retval, false, 0, false, "",
943 					   &piix4_main_adapters[0]);
944 		if (retval < 0)
945 			return retval;
946 	}
947 
948 	/* Check for auxiliary SMBus on some AMD chipsets */
949 	retval = -ENODEV;
950 
951 	if (dev->vendor == PCI_VENDOR_ID_ATI &&
952 	    dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS) {
953 		if (dev->revision < 0x40) {
954 			retval = piix4_setup_aux(dev, id, 0x58);
955 		} else {
956 			/* SB800 added aux bus too */
957 			retval = piix4_setup_sb800(dev, id, 1);
958 		}
959 	}
960 
961 	if (dev->vendor == PCI_VENDOR_ID_AMD &&
962 	    dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) {
963 		retval = piix4_setup_sb800(dev, id, 1);
964 	}
965 
966 	if (retval > 0) {
967 		/* Try to add the aux adapter if it exists,
968 		 * piix4_add_adapter will clean up if this fails */
969 		piix4_add_adapter(dev, retval, false, 0, false,
970 				  is_sb800 ? piix4_aux_port_name_sb800 : "",
971 				  &piix4_aux_adapter);
972 	}
973 
974 	return 0;
975 }
976 
977 static void piix4_adap_remove(struct i2c_adapter *adap)
978 {
979 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
980 
981 	if (adapdata->smba) {
982 		i2c_del_adapter(adap);
983 		if (adapdata->port == (0 << piix4_port_shift_sb800))
984 			release_region(adapdata->smba, SMBIOSIZE);
985 		kfree(adapdata);
986 		kfree(adap);
987 	}
988 }
989 
990 static void piix4_remove(struct pci_dev *dev)
991 {
992 	int port = PIIX4_MAX_ADAPTERS;
993 
994 	while (--port >= 0) {
995 		if (piix4_main_adapters[port]) {
996 			piix4_adap_remove(piix4_main_adapters[port]);
997 			piix4_main_adapters[port] = NULL;
998 		}
999 	}
1000 
1001 	if (piix4_aux_adapter) {
1002 		piix4_adap_remove(piix4_aux_adapter);
1003 		piix4_aux_adapter = NULL;
1004 	}
1005 }
1006 
1007 static struct pci_driver piix4_driver = {
1008 	.name		= "piix4_smbus",
1009 	.id_table	= piix4_ids,
1010 	.probe		= piix4_probe,
1011 	.remove		= piix4_remove,
1012 };
1013 
1014 module_pci_driver(piix4_driver);
1015 
1016 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
1017 		"Philip Edelbrock <phil@netroedge.com>");
1018 MODULE_DESCRIPTION("PIIX4 SMBus driver");
1019 MODULE_LICENSE("GPL");
1020