xref: /openbmc/linux/drivers/i2c/busses/i2c-piix4.c (revision 2c64e9cb)
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 	Hygon CZ
23 	SMSC Victory66
24 
25    Note: we assume there can only be one device, with one or more
26    SMBus interfaces.
27    The device can register multiple i2c_adapters (up to PIIX4_MAX_ADAPTERS).
28    For devices supporting multiple ports the i2c_adapter should provide
29    an i2c_algorithm to access them.
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/slab.h>
41 #include <linux/dmi.h>
42 #include <linux/acpi.h>
43 #include <linux/io.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 #define KERNCZ_IMC_IDX			0x3e
89 #define KERNCZ_IMC_DATA			0x3f
90 
91 /*
92  * SB800 port is selected by bits 2:1 of the smb_en register (0x2c)
93  * or the smb_sel register (0x2e), depending on bit 0 of register 0x2f.
94  * Hudson-2/Bolton port is always selected by bits 2:1 of register 0x2f.
95  */
96 #define SB800_PIIX4_PORT_IDX		0x2c
97 #define SB800_PIIX4_PORT_IDX_ALT	0x2e
98 #define SB800_PIIX4_PORT_IDX_SEL	0x2f
99 #define SB800_PIIX4_PORT_IDX_MASK	0x06
100 #define SB800_PIIX4_PORT_IDX_SHIFT	1
101 
102 /* On kerncz, SmBus0Sel is at bit 20:19 of PMx00 DecodeEn */
103 #define SB800_PIIX4_PORT_IDX_KERNCZ		0x02
104 #define SB800_PIIX4_PORT_IDX_MASK_KERNCZ	0x18
105 #define SB800_PIIX4_PORT_IDX_SHIFT_KERNCZ	3
106 
107 /* insmod parameters */
108 
109 /* If force is set to anything different from 0, we forcibly enable the
110    PIIX4. DANGEROUS! */
111 static int force;
112 module_param (force, int, 0);
113 MODULE_PARM_DESC(force, "Forcibly enable the PIIX4. DANGEROUS!");
114 
115 /* If force_addr is set to anything different from 0, we forcibly enable
116    the PIIX4 at the given address. VERY DANGEROUS! */
117 static int force_addr;
118 module_param_hw(force_addr, int, ioport, 0);
119 MODULE_PARM_DESC(force_addr,
120 		 "Forcibly enable the PIIX4 at the given address. "
121 		 "EXTREMELY DANGEROUS!");
122 
123 static int srvrworks_csb5_delay;
124 static struct pci_driver piix4_driver;
125 
126 static const struct dmi_system_id piix4_dmi_blacklist[] = {
127 	{
128 		.ident = "Sapphire AM2RD790",
129 		.matches = {
130 			DMI_MATCH(DMI_BOARD_VENDOR, "SAPPHIRE Inc."),
131 			DMI_MATCH(DMI_BOARD_NAME, "PC-AM2RD790"),
132 		},
133 	},
134 	{
135 		.ident = "DFI Lanparty UT 790FX",
136 		.matches = {
137 			DMI_MATCH(DMI_BOARD_VENDOR, "DFI Inc."),
138 			DMI_MATCH(DMI_BOARD_NAME, "LP UT 790FX"),
139 		},
140 	},
141 	{ }
142 };
143 
144 /* The IBM entry is in a separate table because we only check it
145    on Intel-based systems */
146 static const struct dmi_system_id piix4_dmi_ibm[] = {
147 	{
148 		.ident = "IBM",
149 		.matches = { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
150 	},
151 	{ },
152 };
153 
154 /*
155  * SB800 globals
156  */
157 static u8 piix4_port_sel_sb800;
158 static u8 piix4_port_mask_sb800;
159 static u8 piix4_port_shift_sb800;
160 static const char *piix4_main_port_names_sb800[PIIX4_MAX_ADAPTERS] = {
161 	" port 0", " port 2", " port 3", " port 4"
162 };
163 static const char *piix4_aux_port_name_sb800 = " port 1";
164 
165 struct i2c_piix4_adapdata {
166 	unsigned short smba;
167 
168 	/* SB800 */
169 	bool sb800_main;
170 	bool notify_imc;
171 	u8 port;		/* Port number, shifted */
172 };
173 
174 static int piix4_setup(struct pci_dev *PIIX4_dev,
175 		       const struct pci_device_id *id)
176 {
177 	unsigned char temp;
178 	unsigned short piix4_smba;
179 
180 	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_SERVERWORKS) &&
181 	    (PIIX4_dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB5))
182 		srvrworks_csb5_delay = 1;
183 
184 	/* On some motherboards, it was reported that accessing the SMBus
185 	   caused severe hardware problems */
186 	if (dmi_check_system(piix4_dmi_blacklist)) {
187 		dev_err(&PIIX4_dev->dev,
188 			"Accessing the SMBus on this system is unsafe!\n");
189 		return -EPERM;
190 	}
191 
192 	/* Don't access SMBus on IBM systems which get corrupted eeproms */
193 	if (dmi_check_system(piix4_dmi_ibm) &&
194 			PIIX4_dev->vendor == PCI_VENDOR_ID_INTEL) {
195 		dev_err(&PIIX4_dev->dev, "IBM system detected; this module "
196 			"may corrupt your serial eeprom! Refusing to load "
197 			"module!\n");
198 		return -EPERM;
199 	}
200 
201 	/* Determine the address of the SMBus areas */
202 	if (force_addr) {
203 		piix4_smba = force_addr & 0xfff0;
204 		force = 0;
205 	} else {
206 		pci_read_config_word(PIIX4_dev, SMBBA, &piix4_smba);
207 		piix4_smba &= 0xfff0;
208 		if(piix4_smba == 0) {
209 			dev_err(&PIIX4_dev->dev, "SMBus base address "
210 				"uninitialized - upgrade BIOS or use "
211 				"force_addr=0xaddr\n");
212 			return -ENODEV;
213 		}
214 	}
215 
216 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
217 		return -ENODEV;
218 
219 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
220 		dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
221 			piix4_smba);
222 		return -EBUSY;
223 	}
224 
225 	pci_read_config_byte(PIIX4_dev, SMBHSTCFG, &temp);
226 
227 	/* If force_addr is set, we program the new address here. Just to make
228 	   sure, we disable the PIIX4 first. */
229 	if (force_addr) {
230 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp & 0xfe);
231 		pci_write_config_word(PIIX4_dev, SMBBA, piix4_smba);
232 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp | 0x01);
233 		dev_info(&PIIX4_dev->dev, "WARNING: SMBus interface set to "
234 			"new address %04x!\n", piix4_smba);
235 	} else if ((temp & 1) == 0) {
236 		if (force) {
237 			/* This should never need to be done, but has been
238 			 * noted that many Dell machines have the SMBus
239 			 * interface on the PIIX4 disabled!? NOTE: This assumes
240 			 * I/O space and other allocations WERE done by the
241 			 * Bios!  Don't complain if your hardware does weird
242 			 * things after enabling this. :') Check for Bios
243 			 * updates before resorting to this.
244 			 */
245 			pci_write_config_byte(PIIX4_dev, SMBHSTCFG,
246 					      temp | 1);
247 			dev_notice(&PIIX4_dev->dev,
248 				   "WARNING: SMBus interface has been FORCEFULLY ENABLED!\n");
249 		} else {
250 			dev_err(&PIIX4_dev->dev,
251 				"SMBus Host Controller not enabled!\n");
252 			release_region(piix4_smba, SMBIOSIZE);
253 			return -ENODEV;
254 		}
255 	}
256 
257 	if (((temp & 0x0E) == 8) || ((temp & 0x0E) == 2))
258 		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
259 	else if ((temp & 0x0E) == 0)
260 		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");
261 	else
262 		dev_err(&PIIX4_dev->dev, "Illegal Interrupt configuration "
263 			"(or code out of date)!\n");
264 
265 	pci_read_config_byte(PIIX4_dev, SMBREV, &temp);
266 	dev_info(&PIIX4_dev->dev,
267 		 "SMBus Host Controller at 0x%x, revision %d\n",
268 		 piix4_smba, temp);
269 
270 	return piix4_smba;
271 }
272 
273 static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
274 			     const struct pci_device_id *id, u8 aux)
275 {
276 	unsigned short piix4_smba;
277 	u8 smba_en_lo, smba_en_hi, smb_en, smb_en_status, port_sel;
278 	u8 i2ccfg, i2ccfg_offset = 0x10;
279 
280 	/* SB800 and later SMBus does not support forcing address */
281 	if (force || force_addr) {
282 		dev_err(&PIIX4_dev->dev, "SMBus does not support "
283 			"forcing address!\n");
284 		return -EINVAL;
285 	}
286 
287 	/* Determine the address of the SMBus areas */
288 	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
289 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
290 	     PIIX4_dev->revision >= 0x41) ||
291 	    (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
292 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
293 	     PIIX4_dev->revision >= 0x49) ||
294 	    (PIIX4_dev->vendor == PCI_VENDOR_ID_HYGON &&
295 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS))
296 		smb_en = 0x00;
297 	else
298 		smb_en = (aux) ? 0x28 : 0x2c;
299 
300 	if (!request_muxed_region(SB800_PIIX4_SMB_IDX, 2, "sb800_piix4_smb")) {
301 		dev_err(&PIIX4_dev->dev,
302 			"SMB base address index region 0x%x already in use.\n",
303 			SB800_PIIX4_SMB_IDX);
304 		return -EBUSY;
305 	}
306 
307 	outb_p(smb_en, SB800_PIIX4_SMB_IDX);
308 	smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
309 	outb_p(smb_en + 1, SB800_PIIX4_SMB_IDX);
310 	smba_en_hi = inb_p(SB800_PIIX4_SMB_IDX + 1);
311 
312 	release_region(SB800_PIIX4_SMB_IDX, 2);
313 
314 	if (!smb_en) {
315 		smb_en_status = smba_en_lo & 0x10;
316 		piix4_smba = smba_en_hi << 8;
317 		if (aux)
318 			piix4_smba |= 0x20;
319 	} else {
320 		smb_en_status = smba_en_lo & 0x01;
321 		piix4_smba = ((smba_en_hi << 8) | smba_en_lo) & 0xffe0;
322 	}
323 
324 	if (!smb_en_status) {
325 		dev_err(&PIIX4_dev->dev,
326 			"SMBus Host Controller not enabled!\n");
327 		return -ENODEV;
328 	}
329 
330 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
331 		return -ENODEV;
332 
333 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
334 		dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
335 			piix4_smba);
336 		return -EBUSY;
337 	}
338 
339 	/* Aux SMBus does not support IRQ information */
340 	if (aux) {
341 		dev_info(&PIIX4_dev->dev,
342 			 "Auxiliary SMBus Host Controller at 0x%x\n",
343 			 piix4_smba);
344 		return piix4_smba;
345 	}
346 
347 	/* Request the SMBus I2C bus config region */
348 	if (!request_region(piix4_smba + i2ccfg_offset, 1, "i2ccfg")) {
349 		dev_err(&PIIX4_dev->dev, "SMBus I2C bus config region "
350 			"0x%x already in use!\n", piix4_smba + i2ccfg_offset);
351 		release_region(piix4_smba, SMBIOSIZE);
352 		return -EBUSY;
353 	}
354 	i2ccfg = inb_p(piix4_smba + i2ccfg_offset);
355 	release_region(piix4_smba + i2ccfg_offset, 1);
356 
357 	if (i2ccfg & 1)
358 		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
359 	else
360 		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");
361 
362 	dev_info(&PIIX4_dev->dev,
363 		 "SMBus Host Controller at 0x%x, revision %d\n",
364 		 piix4_smba, i2ccfg >> 4);
365 
366 	/* Find which register is used for port selection */
367 	if (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD ||
368 	    PIIX4_dev->vendor == PCI_VENDOR_ID_HYGON) {
369 		switch (PIIX4_dev->device) {
370 		case PCI_DEVICE_ID_AMD_KERNCZ_SMBUS:
371 			piix4_port_sel_sb800 = SB800_PIIX4_PORT_IDX_KERNCZ;
372 			piix4_port_mask_sb800 = SB800_PIIX4_PORT_IDX_MASK_KERNCZ;
373 			piix4_port_shift_sb800 = SB800_PIIX4_PORT_IDX_SHIFT_KERNCZ;
374 			break;
375 		case PCI_DEVICE_ID_AMD_HUDSON2_SMBUS:
376 		default:
377 			piix4_port_sel_sb800 = SB800_PIIX4_PORT_IDX_ALT;
378 			piix4_port_mask_sb800 = SB800_PIIX4_PORT_IDX_MASK;
379 			piix4_port_shift_sb800 = SB800_PIIX4_PORT_IDX_SHIFT;
380 			break;
381 		}
382 	} else {
383 		if (!request_muxed_region(SB800_PIIX4_SMB_IDX, 2,
384 					  "sb800_piix4_smb")) {
385 			release_region(piix4_smba, SMBIOSIZE);
386 			return -EBUSY;
387 		}
388 
389 		outb_p(SB800_PIIX4_PORT_IDX_SEL, SB800_PIIX4_SMB_IDX);
390 		port_sel = inb_p(SB800_PIIX4_SMB_IDX + 1);
391 		piix4_port_sel_sb800 = (port_sel & 0x01) ?
392 				       SB800_PIIX4_PORT_IDX_ALT :
393 				       SB800_PIIX4_PORT_IDX;
394 		piix4_port_mask_sb800 = SB800_PIIX4_PORT_IDX_MASK;
395 		piix4_port_shift_sb800 = SB800_PIIX4_PORT_IDX_SHIFT;
396 		release_region(SB800_PIIX4_SMB_IDX, 2);
397 	}
398 
399 	dev_info(&PIIX4_dev->dev,
400 		 "Using register 0x%02x for SMBus port selection\n",
401 		 (unsigned int)piix4_port_sel_sb800);
402 
403 	return piix4_smba;
404 }
405 
406 static int piix4_setup_aux(struct pci_dev *PIIX4_dev,
407 			   const struct pci_device_id *id,
408 			   unsigned short base_reg_addr)
409 {
410 	/* Set up auxiliary SMBus controllers found on some
411 	 * AMD chipsets e.g. SP5100 (SB700 derivative) */
412 
413 	unsigned short piix4_smba;
414 
415 	/* Read address of auxiliary SMBus controller */
416 	pci_read_config_word(PIIX4_dev, base_reg_addr, &piix4_smba);
417 	if ((piix4_smba & 1) == 0) {
418 		dev_dbg(&PIIX4_dev->dev,
419 			"Auxiliary SMBus controller not enabled\n");
420 		return -ENODEV;
421 	}
422 
423 	piix4_smba &= 0xfff0;
424 	if (piix4_smba == 0) {
425 		dev_dbg(&PIIX4_dev->dev,
426 			"Auxiliary SMBus base address uninitialized\n");
427 		return -ENODEV;
428 	}
429 
430 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
431 		return -ENODEV;
432 
433 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
434 		dev_err(&PIIX4_dev->dev, "Auxiliary SMBus region 0x%x "
435 			"already in use!\n", piix4_smba);
436 		return -EBUSY;
437 	}
438 
439 	dev_info(&PIIX4_dev->dev,
440 		 "Auxiliary SMBus Host Controller at 0x%x\n",
441 		 piix4_smba);
442 
443 	return piix4_smba;
444 }
445 
446 static int piix4_transaction(struct i2c_adapter *piix4_adapter)
447 {
448 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(piix4_adapter);
449 	unsigned short piix4_smba = adapdata->smba;
450 	int temp;
451 	int result = 0;
452 	int timeout = 0;
453 
454 	dev_dbg(&piix4_adapter->dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
455 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
456 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
457 		inb_p(SMBHSTDAT1));
458 
459 	/* Make sure the SMBus host is ready to start transmitting */
460 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
461 		dev_dbg(&piix4_adapter->dev, "SMBus busy (%02x). "
462 			"Resetting...\n", temp);
463 		outb_p(temp, SMBHSTSTS);
464 		if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
465 			dev_err(&piix4_adapter->dev, "Failed! (%02x)\n", temp);
466 			return -EBUSY;
467 		} else {
468 			dev_dbg(&piix4_adapter->dev, "Successful!\n");
469 		}
470 	}
471 
472 	/* start the transaction by setting bit 6 */
473 	outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);
474 
475 	/* We will always wait for a fraction of a second! (See PIIX4 docs errata) */
476 	if (srvrworks_csb5_delay) /* Extra delay for SERVERWORKS_CSB5 */
477 		usleep_range(2000, 2100);
478 	else
479 		usleep_range(250, 500);
480 
481 	while ((++timeout < MAX_TIMEOUT) &&
482 	       ((temp = inb_p(SMBHSTSTS)) & 0x01))
483 		usleep_range(250, 500);
484 
485 	/* If the SMBus is still busy, we give up */
486 	if (timeout == MAX_TIMEOUT) {
487 		dev_err(&piix4_adapter->dev, "SMBus Timeout!\n");
488 		result = -ETIMEDOUT;
489 	}
490 
491 	if (temp & 0x10) {
492 		result = -EIO;
493 		dev_err(&piix4_adapter->dev, "Error: Failed bus transaction\n");
494 	}
495 
496 	if (temp & 0x08) {
497 		result = -EIO;
498 		dev_dbg(&piix4_adapter->dev, "Bus collision! SMBus may be "
499 			"locked until next hard reset. (sorry!)\n");
500 		/* Clock stops and slave is stuck in mid-transmission */
501 	}
502 
503 	if (temp & 0x04) {
504 		result = -ENXIO;
505 		dev_dbg(&piix4_adapter->dev, "Error: no response!\n");
506 	}
507 
508 	if (inb_p(SMBHSTSTS) != 0x00)
509 		outb_p(inb(SMBHSTSTS), SMBHSTSTS);
510 
511 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
512 		dev_err(&piix4_adapter->dev, "Failed reset at end of "
513 			"transaction (%02x)\n", temp);
514 	}
515 	dev_dbg(&piix4_adapter->dev, "Transaction (post): CNT=%02x, CMD=%02x, "
516 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
517 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
518 		inb_p(SMBHSTDAT1));
519 	return result;
520 }
521 
522 /* Return negative errno on error. */
523 static s32 piix4_access(struct i2c_adapter * adap, u16 addr,
524 		 unsigned short flags, char read_write,
525 		 u8 command, int size, union i2c_smbus_data * data)
526 {
527 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
528 	unsigned short piix4_smba = adapdata->smba;
529 	int i, len;
530 	int status;
531 
532 	switch (size) {
533 	case I2C_SMBUS_QUICK:
534 		outb_p((addr << 1) | read_write,
535 		       SMBHSTADD);
536 		size = PIIX4_QUICK;
537 		break;
538 	case I2C_SMBUS_BYTE:
539 		outb_p((addr << 1) | read_write,
540 		       SMBHSTADD);
541 		if (read_write == I2C_SMBUS_WRITE)
542 			outb_p(command, SMBHSTCMD);
543 		size = PIIX4_BYTE;
544 		break;
545 	case I2C_SMBUS_BYTE_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->byte, SMBHSTDAT0);
551 		size = PIIX4_BYTE_DATA;
552 		break;
553 	case I2C_SMBUS_WORD_DATA:
554 		outb_p((addr << 1) | read_write,
555 		       SMBHSTADD);
556 		outb_p(command, SMBHSTCMD);
557 		if (read_write == I2C_SMBUS_WRITE) {
558 			outb_p(data->word & 0xff, SMBHSTDAT0);
559 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
560 		}
561 		size = PIIX4_WORD_DATA;
562 		break;
563 	case I2C_SMBUS_BLOCK_DATA:
564 		outb_p((addr << 1) | read_write,
565 		       SMBHSTADD);
566 		outb_p(command, SMBHSTCMD);
567 		if (read_write == I2C_SMBUS_WRITE) {
568 			len = data->block[0];
569 			if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
570 				return -EINVAL;
571 			outb_p(len, SMBHSTDAT0);
572 			inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
573 			for (i = 1; i <= len; i++)
574 				outb_p(data->block[i], SMBBLKDAT);
575 		}
576 		size = PIIX4_BLOCK_DATA;
577 		break;
578 	default:
579 		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
580 		return -EOPNOTSUPP;
581 	}
582 
583 	outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);
584 
585 	status = piix4_transaction(adap);
586 	if (status)
587 		return status;
588 
589 	if ((read_write == I2C_SMBUS_WRITE) || (size == PIIX4_QUICK))
590 		return 0;
591 
592 
593 	switch (size) {
594 	case PIIX4_BYTE:
595 	case PIIX4_BYTE_DATA:
596 		data->byte = inb_p(SMBHSTDAT0);
597 		break;
598 	case PIIX4_WORD_DATA:
599 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
600 		break;
601 	case PIIX4_BLOCK_DATA:
602 		data->block[0] = inb_p(SMBHSTDAT0);
603 		if (data->block[0] == 0 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
604 			return -EPROTO;
605 		inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
606 		for (i = 1; i <= data->block[0]; i++)
607 			data->block[i] = inb_p(SMBBLKDAT);
608 		break;
609 	}
610 	return 0;
611 }
612 
613 static uint8_t piix4_imc_read(uint8_t idx)
614 {
615 	outb_p(idx, KERNCZ_IMC_IDX);
616 	return inb_p(KERNCZ_IMC_DATA);
617 }
618 
619 static void piix4_imc_write(uint8_t idx, uint8_t value)
620 {
621 	outb_p(idx, KERNCZ_IMC_IDX);
622 	outb_p(value, KERNCZ_IMC_DATA);
623 }
624 
625 static int piix4_imc_sleep(void)
626 {
627 	int timeout = MAX_TIMEOUT;
628 
629 	if (!request_muxed_region(KERNCZ_IMC_IDX, 2, "smbus_kerncz_imc"))
630 		return -EBUSY;
631 
632 	/* clear response register */
633 	piix4_imc_write(0x82, 0x00);
634 	/* request ownership flag */
635 	piix4_imc_write(0x83, 0xB4);
636 	/* kick off IMC Mailbox command 96 */
637 	piix4_imc_write(0x80, 0x96);
638 
639 	while (timeout--) {
640 		if (piix4_imc_read(0x82) == 0xfa) {
641 			release_region(KERNCZ_IMC_IDX, 2);
642 			return 0;
643 		}
644 		usleep_range(1000, 2000);
645 	}
646 
647 	release_region(KERNCZ_IMC_IDX, 2);
648 	return -ETIMEDOUT;
649 }
650 
651 static void piix4_imc_wakeup(void)
652 {
653 	int timeout = MAX_TIMEOUT;
654 
655 	if (!request_muxed_region(KERNCZ_IMC_IDX, 2, "smbus_kerncz_imc"))
656 		return;
657 
658 	/* clear response register */
659 	piix4_imc_write(0x82, 0x00);
660 	/* release ownership flag */
661 	piix4_imc_write(0x83, 0xB5);
662 	/* kick off IMC Mailbox command 96 */
663 	piix4_imc_write(0x80, 0x96);
664 
665 	while (timeout--) {
666 		if (piix4_imc_read(0x82) == 0xfa)
667 			break;
668 		usleep_range(1000, 2000);
669 	}
670 
671 	release_region(KERNCZ_IMC_IDX, 2);
672 }
673 
674 /*
675  * Handles access to multiple SMBus ports on the SB800.
676  * The port is selected by bits 2:1 of the smb_en register (0x2c).
677  * Returns negative errno on error.
678  *
679  * Note: The selected port must be returned to the initial selection to avoid
680  * problems on certain systems.
681  */
682 static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
683 		 unsigned short flags, char read_write,
684 		 u8 command, int size, union i2c_smbus_data *data)
685 {
686 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
687 	unsigned short piix4_smba = adapdata->smba;
688 	int retries = MAX_TIMEOUT;
689 	int smbslvcnt;
690 	u8 smba_en_lo;
691 	u8 port;
692 	int retval;
693 
694 	if (!request_muxed_region(SB800_PIIX4_SMB_IDX, 2, "sb800_piix4_smb"))
695 		return -EBUSY;
696 
697 	/* Request the SMBUS semaphore, avoid conflicts with the IMC */
698 	smbslvcnt  = inb_p(SMBSLVCNT);
699 	do {
700 		outb_p(smbslvcnt | 0x10, SMBSLVCNT);
701 
702 		/* Check the semaphore status */
703 		smbslvcnt  = inb_p(SMBSLVCNT);
704 		if (smbslvcnt & 0x10)
705 			break;
706 
707 		usleep_range(1000, 2000);
708 	} while (--retries);
709 	/* SMBus is still owned by the IMC, we give up */
710 	if (!retries) {
711 		retval = -EBUSY;
712 		goto release;
713 	}
714 
715 	/*
716 	 * Notify the IMC (Integrated Micro Controller) if required.
717 	 * Among other responsibilities, the IMC is in charge of monitoring
718 	 * the System fans and temperature sensors, and act accordingly.
719 	 * All this is done through SMBus and can/will collide
720 	 * with our transactions if they are long (BLOCK_DATA).
721 	 * Therefore we need to request the ownership flag during those
722 	 * transactions.
723 	 */
724 	if ((size == I2C_SMBUS_BLOCK_DATA) && adapdata->notify_imc) {
725 		int ret;
726 
727 		ret = piix4_imc_sleep();
728 		switch (ret) {
729 		case -EBUSY:
730 			dev_warn(&adap->dev,
731 				 "IMC base address index region 0x%x already in use.\n",
732 				 KERNCZ_IMC_IDX);
733 			break;
734 		case -ETIMEDOUT:
735 			dev_warn(&adap->dev,
736 				 "Failed to communicate with the IMC.\n");
737 			break;
738 		default:
739 			break;
740 		}
741 
742 		/* If IMC communication fails do not retry */
743 		if (ret) {
744 			dev_warn(&adap->dev,
745 				 "Continuing without IMC notification.\n");
746 			adapdata->notify_imc = false;
747 		}
748 	}
749 
750 	outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX);
751 	smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
752 
753 	port = adapdata->port;
754 	if ((smba_en_lo & piix4_port_mask_sb800) != port)
755 		outb_p((smba_en_lo & ~piix4_port_mask_sb800) | port,
756 		       SB800_PIIX4_SMB_IDX + 1);
757 
758 	retval = piix4_access(adap, addr, flags, read_write,
759 			      command, size, data);
760 
761 	outb_p(smba_en_lo, SB800_PIIX4_SMB_IDX + 1);
762 
763 	/* Release the semaphore */
764 	outb_p(smbslvcnt | 0x20, SMBSLVCNT);
765 
766 	if ((size == I2C_SMBUS_BLOCK_DATA) && adapdata->notify_imc)
767 		piix4_imc_wakeup();
768 
769 release:
770 	release_region(SB800_PIIX4_SMB_IDX, 2);
771 	return retval;
772 }
773 
774 static u32 piix4_func(struct i2c_adapter *adapter)
775 {
776 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
777 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
778 	    I2C_FUNC_SMBUS_BLOCK_DATA;
779 }
780 
781 static const struct i2c_algorithm smbus_algorithm = {
782 	.smbus_xfer	= piix4_access,
783 	.functionality	= piix4_func,
784 };
785 
786 static const struct i2c_algorithm piix4_smbus_algorithm_sb800 = {
787 	.smbus_xfer	= piix4_access_sb800,
788 	.functionality	= piix4_func,
789 };
790 
791 static const struct pci_device_id piix4_ids[] = {
792 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
793 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3) },
794 	{ PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_SLC90E66_3) },
795 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP200_SMBUS) },
796 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP300_SMBUS) },
797 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS) },
798 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS) },
799 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) },
800 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) },
801 	{ PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) },
802 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
803 		     PCI_DEVICE_ID_SERVERWORKS_OSB4) },
804 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
805 		     PCI_DEVICE_ID_SERVERWORKS_CSB5) },
806 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
807 		     PCI_DEVICE_ID_SERVERWORKS_CSB6) },
808 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
809 		     PCI_DEVICE_ID_SERVERWORKS_HT1000SB) },
810 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
811 		     PCI_DEVICE_ID_SERVERWORKS_HT1100LD) },
812 	{ 0, }
813 };
814 
815 MODULE_DEVICE_TABLE (pci, piix4_ids);
816 
817 static struct i2c_adapter *piix4_main_adapters[PIIX4_MAX_ADAPTERS];
818 static struct i2c_adapter *piix4_aux_adapter;
819 
820 static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
821 			     bool sb800_main, u8 port, bool notify_imc,
822 			     const char *name, struct i2c_adapter **padap)
823 {
824 	struct i2c_adapter *adap;
825 	struct i2c_piix4_adapdata *adapdata;
826 	int retval;
827 
828 	adap = kzalloc(sizeof(*adap), GFP_KERNEL);
829 	if (adap == NULL) {
830 		release_region(smba, SMBIOSIZE);
831 		return -ENOMEM;
832 	}
833 
834 	adap->owner = THIS_MODULE;
835 	adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
836 	adap->algo = sb800_main ? &piix4_smbus_algorithm_sb800
837 				: &smbus_algorithm;
838 
839 	adapdata = kzalloc(sizeof(*adapdata), GFP_KERNEL);
840 	if (adapdata == NULL) {
841 		kfree(adap);
842 		release_region(smba, SMBIOSIZE);
843 		return -ENOMEM;
844 	}
845 
846 	adapdata->smba = smba;
847 	adapdata->sb800_main = sb800_main;
848 	adapdata->port = port << piix4_port_shift_sb800;
849 	adapdata->notify_imc = notify_imc;
850 
851 	/* set up the sysfs linkage to our parent device */
852 	adap->dev.parent = &dev->dev;
853 
854 	snprintf(adap->name, sizeof(adap->name),
855 		"SMBus PIIX4 adapter%s at %04x", name, smba);
856 
857 	i2c_set_adapdata(adap, adapdata);
858 
859 	retval = i2c_add_adapter(adap);
860 	if (retval) {
861 		kfree(adapdata);
862 		kfree(adap);
863 		release_region(smba, SMBIOSIZE);
864 		return retval;
865 	}
866 
867 	*padap = adap;
868 	return 0;
869 }
870 
871 static int piix4_add_adapters_sb800(struct pci_dev *dev, unsigned short smba,
872 				    bool notify_imc)
873 {
874 	struct i2c_piix4_adapdata *adapdata;
875 	int port;
876 	int retval;
877 
878 	for (port = 0; port < PIIX4_MAX_ADAPTERS; port++) {
879 		retval = piix4_add_adapter(dev, smba, true, port, notify_imc,
880 					   piix4_main_port_names_sb800[port],
881 					   &piix4_main_adapters[port]);
882 		if (retval < 0)
883 			goto error;
884 	}
885 
886 	return retval;
887 
888 error:
889 	dev_err(&dev->dev,
890 		"Error setting up SB800 adapters. Unregistering!\n");
891 	while (--port >= 0) {
892 		adapdata = i2c_get_adapdata(piix4_main_adapters[port]);
893 		if (adapdata->smba) {
894 			i2c_del_adapter(piix4_main_adapters[port]);
895 			kfree(adapdata);
896 			kfree(piix4_main_adapters[port]);
897 			piix4_main_adapters[port] = NULL;
898 		}
899 	}
900 
901 	return retval;
902 }
903 
904 static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
905 {
906 	int retval;
907 	bool is_sb800 = false;
908 
909 	if ((dev->vendor == PCI_VENDOR_ID_ATI &&
910 	     dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
911 	     dev->revision >= 0x40) ||
912 	    dev->vendor == PCI_VENDOR_ID_AMD ||
913 	    dev->vendor == PCI_VENDOR_ID_HYGON) {
914 		bool notify_imc = false;
915 		is_sb800 = true;
916 
917 		if ((dev->vendor == PCI_VENDOR_ID_AMD ||
918 		     dev->vendor == PCI_VENDOR_ID_HYGON) &&
919 		    dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) {
920 			u8 imc;
921 
922 			/*
923 			 * Detect if IMC is active or not, this method is
924 			 * described on coreboot's AMD IMC notes
925 			 */
926 			pci_bus_read_config_byte(dev->bus, PCI_DEVFN(0x14, 3),
927 						 0x40, &imc);
928 			if (imc & 0x80)
929 				notify_imc = true;
930 		}
931 
932 		/* base address location etc changed in SB800 */
933 		retval = piix4_setup_sb800(dev, id, 0);
934 		if (retval < 0)
935 			return retval;
936 
937 		/*
938 		 * Try to register multiplexed main SMBus adapter,
939 		 * give up if we can't
940 		 */
941 		retval = piix4_add_adapters_sb800(dev, retval, notify_imc);
942 		if (retval < 0)
943 			return retval;
944 	} else {
945 		retval = piix4_setup(dev, id);
946 		if (retval < 0)
947 			return retval;
948 
949 		/* Try to register main SMBus adapter, give up if we can't */
950 		retval = piix4_add_adapter(dev, retval, false, 0, false, "",
951 					   &piix4_main_adapters[0]);
952 		if (retval < 0)
953 			return retval;
954 	}
955 
956 	/* Check for auxiliary SMBus on some AMD chipsets */
957 	retval = -ENODEV;
958 
959 	if (dev->vendor == PCI_VENDOR_ID_ATI &&
960 	    dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS) {
961 		if (dev->revision < 0x40) {
962 			retval = piix4_setup_aux(dev, id, 0x58);
963 		} else {
964 			/* SB800 added aux bus too */
965 			retval = piix4_setup_sb800(dev, id, 1);
966 		}
967 	}
968 
969 	if (dev->vendor == PCI_VENDOR_ID_AMD &&
970 	    dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) {
971 		retval = piix4_setup_sb800(dev, id, 1);
972 	}
973 
974 	if (retval > 0) {
975 		/* Try to add the aux adapter if it exists,
976 		 * piix4_add_adapter will clean up if this fails */
977 		piix4_add_adapter(dev, retval, false, 0, false,
978 				  is_sb800 ? piix4_aux_port_name_sb800 : "",
979 				  &piix4_aux_adapter);
980 	}
981 
982 	return 0;
983 }
984 
985 static void piix4_adap_remove(struct i2c_adapter *adap)
986 {
987 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
988 
989 	if (adapdata->smba) {
990 		i2c_del_adapter(adap);
991 		if (adapdata->port == (0 << piix4_port_shift_sb800))
992 			release_region(adapdata->smba, SMBIOSIZE);
993 		kfree(adapdata);
994 		kfree(adap);
995 	}
996 }
997 
998 static void piix4_remove(struct pci_dev *dev)
999 {
1000 	int port = PIIX4_MAX_ADAPTERS;
1001 
1002 	while (--port >= 0) {
1003 		if (piix4_main_adapters[port]) {
1004 			piix4_adap_remove(piix4_main_adapters[port]);
1005 			piix4_main_adapters[port] = NULL;
1006 		}
1007 	}
1008 
1009 	if (piix4_aux_adapter) {
1010 		piix4_adap_remove(piix4_aux_adapter);
1011 		piix4_aux_adapter = NULL;
1012 	}
1013 }
1014 
1015 static struct pci_driver piix4_driver = {
1016 	.name		= "piix4_smbus",
1017 	.id_table	= piix4_ids,
1018 	.probe		= piix4_probe,
1019 	.remove		= piix4_remove,
1020 };
1021 
1022 module_pci_driver(piix4_driver);
1023 
1024 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
1025 		"Philip Edelbrock <phil@netroedge.com>");
1026 MODULE_DESCRIPTION("PIIX4 SMBus driver");
1027 MODULE_LICENSE("GPL");
1028