xref: /openbmc/linux/drivers/i2c/busses/i2c-piix4.c (revision 20e2fc42)
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 #define HUDSON2_MAIN_PORTS	2 /* HUDSON2, KERNCZ reserves ports 3, 4 */
77 
78 /* SB800 constants */
79 #define SB800_PIIX4_SMB_IDX		0xcd6
80 
81 #define KERNCZ_IMC_IDX			0x3e
82 #define KERNCZ_IMC_DATA			0x3f
83 
84 /*
85  * SB800 port is selected by bits 2:1 of the smb_en register (0x2c)
86  * or the smb_sel register (0x2e), depending on bit 0 of register 0x2f.
87  * Hudson-2/Bolton port is always selected by bits 2:1 of register 0x2f.
88  */
89 #define SB800_PIIX4_PORT_IDX		0x2c
90 #define SB800_PIIX4_PORT_IDX_ALT	0x2e
91 #define SB800_PIIX4_PORT_IDX_SEL	0x2f
92 #define SB800_PIIX4_PORT_IDX_MASK	0x06
93 #define SB800_PIIX4_PORT_IDX_SHIFT	1
94 
95 /* On kerncz and Hudson2, SmBus0Sel is at bit 20:19 of PMx00 DecodeEn */
96 #define SB800_PIIX4_PORT_IDX_KERNCZ		0x02
97 #define SB800_PIIX4_PORT_IDX_MASK_KERNCZ	0x18
98 #define SB800_PIIX4_PORT_IDX_SHIFT_KERNCZ	3
99 
100 /* insmod parameters */
101 
102 /* If force is set to anything different from 0, we forcibly enable the
103    PIIX4. DANGEROUS! */
104 static int force;
105 module_param (force, int, 0);
106 MODULE_PARM_DESC(force, "Forcibly enable the PIIX4. DANGEROUS!");
107 
108 /* If force_addr is set to anything different from 0, we forcibly enable
109    the PIIX4 at the given address. VERY DANGEROUS! */
110 static int force_addr;
111 module_param_hw(force_addr, int, ioport, 0);
112 MODULE_PARM_DESC(force_addr,
113 		 "Forcibly enable the PIIX4 at the given address. "
114 		 "EXTREMELY DANGEROUS!");
115 
116 static int srvrworks_csb5_delay;
117 static struct pci_driver piix4_driver;
118 
119 static const struct dmi_system_id piix4_dmi_blacklist[] = {
120 	{
121 		.ident = "Sapphire AM2RD790",
122 		.matches = {
123 			DMI_MATCH(DMI_BOARD_VENDOR, "SAPPHIRE Inc."),
124 			DMI_MATCH(DMI_BOARD_NAME, "PC-AM2RD790"),
125 		},
126 	},
127 	{
128 		.ident = "DFI Lanparty UT 790FX",
129 		.matches = {
130 			DMI_MATCH(DMI_BOARD_VENDOR, "DFI Inc."),
131 			DMI_MATCH(DMI_BOARD_NAME, "LP UT 790FX"),
132 		},
133 	},
134 	{ }
135 };
136 
137 /* The IBM entry is in a separate table because we only check it
138    on Intel-based systems */
139 static const struct dmi_system_id piix4_dmi_ibm[] = {
140 	{
141 		.ident = "IBM",
142 		.matches = { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
143 	},
144 	{ },
145 };
146 
147 /*
148  * SB800 globals
149  */
150 static u8 piix4_port_sel_sb800;
151 static u8 piix4_port_mask_sb800;
152 static u8 piix4_port_shift_sb800;
153 static const char *piix4_main_port_names_sb800[PIIX4_MAX_ADAPTERS] = {
154 	" port 0", " port 2", " port 3", " port 4"
155 };
156 static const char *piix4_aux_port_name_sb800 = " port 1";
157 
158 struct i2c_piix4_adapdata {
159 	unsigned short smba;
160 
161 	/* SB800 */
162 	bool sb800_main;
163 	bool notify_imc;
164 	u8 port;		/* Port number, shifted */
165 };
166 
167 static int piix4_setup(struct pci_dev *PIIX4_dev,
168 		       const struct pci_device_id *id)
169 {
170 	unsigned char temp;
171 	unsigned short piix4_smba;
172 
173 	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_SERVERWORKS) &&
174 	    (PIIX4_dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB5))
175 		srvrworks_csb5_delay = 1;
176 
177 	/* On some motherboards, it was reported that accessing the SMBus
178 	   caused severe hardware problems */
179 	if (dmi_check_system(piix4_dmi_blacklist)) {
180 		dev_err(&PIIX4_dev->dev,
181 			"Accessing the SMBus on this system is unsafe!\n");
182 		return -EPERM;
183 	}
184 
185 	/* Don't access SMBus on IBM systems which get corrupted eeproms */
186 	if (dmi_check_system(piix4_dmi_ibm) &&
187 			PIIX4_dev->vendor == PCI_VENDOR_ID_INTEL) {
188 		dev_err(&PIIX4_dev->dev, "IBM system detected; this module "
189 			"may corrupt your serial eeprom! Refusing to load "
190 			"module!\n");
191 		return -EPERM;
192 	}
193 
194 	/* Determine the address of the SMBus areas */
195 	if (force_addr) {
196 		piix4_smba = force_addr & 0xfff0;
197 		force = 0;
198 	} else {
199 		pci_read_config_word(PIIX4_dev, SMBBA, &piix4_smba);
200 		piix4_smba &= 0xfff0;
201 		if(piix4_smba == 0) {
202 			dev_err(&PIIX4_dev->dev, "SMBus base address "
203 				"uninitialized - upgrade BIOS or use "
204 				"force_addr=0xaddr\n");
205 			return -ENODEV;
206 		}
207 	}
208 
209 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
210 		return -ENODEV;
211 
212 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
213 		dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
214 			piix4_smba);
215 		return -EBUSY;
216 	}
217 
218 	pci_read_config_byte(PIIX4_dev, SMBHSTCFG, &temp);
219 
220 	/* If force_addr is set, we program the new address here. Just to make
221 	   sure, we disable the PIIX4 first. */
222 	if (force_addr) {
223 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp & 0xfe);
224 		pci_write_config_word(PIIX4_dev, SMBBA, piix4_smba);
225 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp | 0x01);
226 		dev_info(&PIIX4_dev->dev, "WARNING: SMBus interface set to "
227 			"new address %04x!\n", piix4_smba);
228 	} else if ((temp & 1) == 0) {
229 		if (force) {
230 			/* This should never need to be done, but has been
231 			 * noted that many Dell machines have the SMBus
232 			 * interface on the PIIX4 disabled!? NOTE: This assumes
233 			 * I/O space and other allocations WERE done by the
234 			 * Bios!  Don't complain if your hardware does weird
235 			 * things after enabling this. :') Check for Bios
236 			 * updates before resorting to this.
237 			 */
238 			pci_write_config_byte(PIIX4_dev, SMBHSTCFG,
239 					      temp | 1);
240 			dev_notice(&PIIX4_dev->dev,
241 				   "WARNING: SMBus interface has been FORCEFULLY ENABLED!\n");
242 		} else {
243 			dev_err(&PIIX4_dev->dev,
244 				"SMBus Host Controller not enabled!\n");
245 			release_region(piix4_smba, SMBIOSIZE);
246 			return -ENODEV;
247 		}
248 	}
249 
250 	if (((temp & 0x0E) == 8) || ((temp & 0x0E) == 2))
251 		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
252 	else if ((temp & 0x0E) == 0)
253 		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");
254 	else
255 		dev_err(&PIIX4_dev->dev, "Illegal Interrupt configuration "
256 			"(or code out of date)!\n");
257 
258 	pci_read_config_byte(PIIX4_dev, SMBREV, &temp);
259 	dev_info(&PIIX4_dev->dev,
260 		 "SMBus Host Controller at 0x%x, revision %d\n",
261 		 piix4_smba, temp);
262 
263 	return piix4_smba;
264 }
265 
266 static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
267 			     const struct pci_device_id *id, u8 aux)
268 {
269 	unsigned short piix4_smba;
270 	u8 smba_en_lo, smba_en_hi, smb_en, smb_en_status, port_sel;
271 	u8 i2ccfg, i2ccfg_offset = 0x10;
272 
273 	/* SB800 and later SMBus does not support forcing address */
274 	if (force || force_addr) {
275 		dev_err(&PIIX4_dev->dev, "SMBus does not support "
276 			"forcing address!\n");
277 		return -EINVAL;
278 	}
279 
280 	/* Determine the address of the SMBus areas */
281 	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
282 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
283 	     PIIX4_dev->revision >= 0x41) ||
284 	    (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
285 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
286 	     PIIX4_dev->revision >= 0x49) ||
287 	    (PIIX4_dev->vendor == PCI_VENDOR_ID_HYGON &&
288 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS))
289 		smb_en = 0x00;
290 	else
291 		smb_en = (aux) ? 0x28 : 0x2c;
292 
293 	if (!request_muxed_region(SB800_PIIX4_SMB_IDX, 2, "sb800_piix4_smb")) {
294 		dev_err(&PIIX4_dev->dev,
295 			"SMB base address index region 0x%x already in use.\n",
296 			SB800_PIIX4_SMB_IDX);
297 		return -EBUSY;
298 	}
299 
300 	outb_p(smb_en, SB800_PIIX4_SMB_IDX);
301 	smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
302 	outb_p(smb_en + 1, SB800_PIIX4_SMB_IDX);
303 	smba_en_hi = inb_p(SB800_PIIX4_SMB_IDX + 1);
304 
305 	release_region(SB800_PIIX4_SMB_IDX, 2);
306 
307 	if (!smb_en) {
308 		smb_en_status = smba_en_lo & 0x10;
309 		piix4_smba = smba_en_hi << 8;
310 		if (aux)
311 			piix4_smba |= 0x20;
312 	} else {
313 		smb_en_status = smba_en_lo & 0x01;
314 		piix4_smba = ((smba_en_hi << 8) | smba_en_lo) & 0xffe0;
315 	}
316 
317 	if (!smb_en_status) {
318 		dev_err(&PIIX4_dev->dev,
319 			"SMBus Host Controller not enabled!\n");
320 		return -ENODEV;
321 	}
322 
323 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
324 		return -ENODEV;
325 
326 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
327 		dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
328 			piix4_smba);
329 		return -EBUSY;
330 	}
331 
332 	/* Aux SMBus does not support IRQ information */
333 	if (aux) {
334 		dev_info(&PIIX4_dev->dev,
335 			 "Auxiliary SMBus Host Controller at 0x%x\n",
336 			 piix4_smba);
337 		return piix4_smba;
338 	}
339 
340 	/* Request the SMBus I2C bus config region */
341 	if (!request_region(piix4_smba + i2ccfg_offset, 1, "i2ccfg")) {
342 		dev_err(&PIIX4_dev->dev, "SMBus I2C bus config region "
343 			"0x%x already in use!\n", piix4_smba + i2ccfg_offset);
344 		release_region(piix4_smba, SMBIOSIZE);
345 		return -EBUSY;
346 	}
347 	i2ccfg = inb_p(piix4_smba + i2ccfg_offset);
348 	release_region(piix4_smba + i2ccfg_offset, 1);
349 
350 	if (i2ccfg & 1)
351 		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
352 	else
353 		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");
354 
355 	dev_info(&PIIX4_dev->dev,
356 		 "SMBus Host Controller at 0x%x, revision %d\n",
357 		 piix4_smba, i2ccfg >> 4);
358 
359 	/* Find which register is used for port selection */
360 	if (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD ||
361 	    PIIX4_dev->vendor == PCI_VENDOR_ID_HYGON) {
362 		if (PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS ||
363 		    (PIIX4_dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
364 		     PIIX4_dev->revision >= 0x1F)) {
365 			piix4_port_sel_sb800 = SB800_PIIX4_PORT_IDX_KERNCZ;
366 			piix4_port_mask_sb800 = SB800_PIIX4_PORT_IDX_MASK_KERNCZ;
367 			piix4_port_shift_sb800 = SB800_PIIX4_PORT_IDX_SHIFT_KERNCZ;
368 		} else {
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 		}
373 	} else {
374 		if (!request_muxed_region(SB800_PIIX4_SMB_IDX, 2,
375 					  "sb800_piix4_smb")) {
376 			release_region(piix4_smba, SMBIOSIZE);
377 			return -EBUSY;
378 		}
379 
380 		outb_p(SB800_PIIX4_PORT_IDX_SEL, SB800_PIIX4_SMB_IDX);
381 		port_sel = inb_p(SB800_PIIX4_SMB_IDX + 1);
382 		piix4_port_sel_sb800 = (port_sel & 0x01) ?
383 				       SB800_PIIX4_PORT_IDX_ALT :
384 				       SB800_PIIX4_PORT_IDX;
385 		piix4_port_mask_sb800 = SB800_PIIX4_PORT_IDX_MASK;
386 		piix4_port_shift_sb800 = SB800_PIIX4_PORT_IDX_SHIFT;
387 		release_region(SB800_PIIX4_SMB_IDX, 2);
388 	}
389 
390 	dev_info(&PIIX4_dev->dev,
391 		 "Using register 0x%02x for SMBus port selection\n",
392 		 (unsigned int)piix4_port_sel_sb800);
393 
394 	return piix4_smba;
395 }
396 
397 static int piix4_setup_aux(struct pci_dev *PIIX4_dev,
398 			   const struct pci_device_id *id,
399 			   unsigned short base_reg_addr)
400 {
401 	/* Set up auxiliary SMBus controllers found on some
402 	 * AMD chipsets e.g. SP5100 (SB700 derivative) */
403 
404 	unsigned short piix4_smba;
405 
406 	/* Read address of auxiliary SMBus controller */
407 	pci_read_config_word(PIIX4_dev, base_reg_addr, &piix4_smba);
408 	if ((piix4_smba & 1) == 0) {
409 		dev_dbg(&PIIX4_dev->dev,
410 			"Auxiliary SMBus controller not enabled\n");
411 		return -ENODEV;
412 	}
413 
414 	piix4_smba &= 0xfff0;
415 	if (piix4_smba == 0) {
416 		dev_dbg(&PIIX4_dev->dev,
417 			"Auxiliary SMBus base address uninitialized\n");
418 		return -ENODEV;
419 	}
420 
421 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
422 		return -ENODEV;
423 
424 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
425 		dev_err(&PIIX4_dev->dev, "Auxiliary SMBus region 0x%x "
426 			"already in use!\n", piix4_smba);
427 		return -EBUSY;
428 	}
429 
430 	dev_info(&PIIX4_dev->dev,
431 		 "Auxiliary SMBus Host Controller at 0x%x\n",
432 		 piix4_smba);
433 
434 	return piix4_smba;
435 }
436 
437 static int piix4_transaction(struct i2c_adapter *piix4_adapter)
438 {
439 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(piix4_adapter);
440 	unsigned short piix4_smba = adapdata->smba;
441 	int temp;
442 	int result = 0;
443 	int timeout = 0;
444 
445 	dev_dbg(&piix4_adapter->dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
446 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
447 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
448 		inb_p(SMBHSTDAT1));
449 
450 	/* Make sure the SMBus host is ready to start transmitting */
451 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
452 		dev_dbg(&piix4_adapter->dev, "SMBus busy (%02x). "
453 			"Resetting...\n", temp);
454 		outb_p(temp, SMBHSTSTS);
455 		if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
456 			dev_err(&piix4_adapter->dev, "Failed! (%02x)\n", temp);
457 			return -EBUSY;
458 		} else {
459 			dev_dbg(&piix4_adapter->dev, "Successful!\n");
460 		}
461 	}
462 
463 	/* start the transaction by setting bit 6 */
464 	outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);
465 
466 	/* We will always wait for a fraction of a second! (See PIIX4 docs errata) */
467 	if (srvrworks_csb5_delay) /* Extra delay for SERVERWORKS_CSB5 */
468 		usleep_range(2000, 2100);
469 	else
470 		usleep_range(250, 500);
471 
472 	while ((++timeout < MAX_TIMEOUT) &&
473 	       ((temp = inb_p(SMBHSTSTS)) & 0x01))
474 		usleep_range(250, 500);
475 
476 	/* If the SMBus is still busy, we give up */
477 	if (timeout == MAX_TIMEOUT) {
478 		dev_err(&piix4_adapter->dev, "SMBus Timeout!\n");
479 		result = -ETIMEDOUT;
480 	}
481 
482 	if (temp & 0x10) {
483 		result = -EIO;
484 		dev_err(&piix4_adapter->dev, "Error: Failed bus transaction\n");
485 	}
486 
487 	if (temp & 0x08) {
488 		result = -EIO;
489 		dev_dbg(&piix4_adapter->dev, "Bus collision! SMBus may be "
490 			"locked until next hard reset. (sorry!)\n");
491 		/* Clock stops and slave is stuck in mid-transmission */
492 	}
493 
494 	if (temp & 0x04) {
495 		result = -ENXIO;
496 		dev_dbg(&piix4_adapter->dev, "Error: no response!\n");
497 	}
498 
499 	if (inb_p(SMBHSTSTS) != 0x00)
500 		outb_p(inb(SMBHSTSTS), SMBHSTSTS);
501 
502 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
503 		dev_err(&piix4_adapter->dev, "Failed reset at end of "
504 			"transaction (%02x)\n", temp);
505 	}
506 	dev_dbg(&piix4_adapter->dev, "Transaction (post): CNT=%02x, CMD=%02x, "
507 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
508 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
509 		inb_p(SMBHSTDAT1));
510 	return result;
511 }
512 
513 /* Return negative errno on error. */
514 static s32 piix4_access(struct i2c_adapter * adap, u16 addr,
515 		 unsigned short flags, char read_write,
516 		 u8 command, int size, union i2c_smbus_data * data)
517 {
518 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
519 	unsigned short piix4_smba = adapdata->smba;
520 	int i, len;
521 	int status;
522 
523 	switch (size) {
524 	case I2C_SMBUS_QUICK:
525 		outb_p((addr << 1) | read_write,
526 		       SMBHSTADD);
527 		size = PIIX4_QUICK;
528 		break;
529 	case I2C_SMBUS_BYTE:
530 		outb_p((addr << 1) | read_write,
531 		       SMBHSTADD);
532 		if (read_write == I2C_SMBUS_WRITE)
533 			outb_p(command, SMBHSTCMD);
534 		size = PIIX4_BYTE;
535 		break;
536 	case I2C_SMBUS_BYTE_DATA:
537 		outb_p((addr << 1) | read_write,
538 		       SMBHSTADD);
539 		outb_p(command, SMBHSTCMD);
540 		if (read_write == I2C_SMBUS_WRITE)
541 			outb_p(data->byte, SMBHSTDAT0);
542 		size = PIIX4_BYTE_DATA;
543 		break;
544 	case I2C_SMBUS_WORD_DATA:
545 		outb_p((addr << 1) | read_write,
546 		       SMBHSTADD);
547 		outb_p(command, SMBHSTCMD);
548 		if (read_write == I2C_SMBUS_WRITE) {
549 			outb_p(data->word & 0xff, SMBHSTDAT0);
550 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
551 		}
552 		size = PIIX4_WORD_DATA;
553 		break;
554 	case I2C_SMBUS_BLOCK_DATA:
555 		outb_p((addr << 1) | read_write,
556 		       SMBHSTADD);
557 		outb_p(command, SMBHSTCMD);
558 		if (read_write == I2C_SMBUS_WRITE) {
559 			len = data->block[0];
560 			if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
561 				return -EINVAL;
562 			outb_p(len, SMBHSTDAT0);
563 			inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
564 			for (i = 1; i <= len; i++)
565 				outb_p(data->block[i], SMBBLKDAT);
566 		}
567 		size = PIIX4_BLOCK_DATA;
568 		break;
569 	default:
570 		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
571 		return -EOPNOTSUPP;
572 	}
573 
574 	outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);
575 
576 	status = piix4_transaction(adap);
577 	if (status)
578 		return status;
579 
580 	if ((read_write == I2C_SMBUS_WRITE) || (size == PIIX4_QUICK))
581 		return 0;
582 
583 
584 	switch (size) {
585 	case PIIX4_BYTE:
586 	case PIIX4_BYTE_DATA:
587 		data->byte = inb_p(SMBHSTDAT0);
588 		break;
589 	case PIIX4_WORD_DATA:
590 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
591 		break;
592 	case PIIX4_BLOCK_DATA:
593 		data->block[0] = inb_p(SMBHSTDAT0);
594 		if (data->block[0] == 0 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
595 			return -EPROTO;
596 		inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
597 		for (i = 1; i <= data->block[0]; i++)
598 			data->block[i] = inb_p(SMBBLKDAT);
599 		break;
600 	}
601 	return 0;
602 }
603 
604 static uint8_t piix4_imc_read(uint8_t idx)
605 {
606 	outb_p(idx, KERNCZ_IMC_IDX);
607 	return inb_p(KERNCZ_IMC_DATA);
608 }
609 
610 static void piix4_imc_write(uint8_t idx, uint8_t value)
611 {
612 	outb_p(idx, KERNCZ_IMC_IDX);
613 	outb_p(value, KERNCZ_IMC_DATA);
614 }
615 
616 static int piix4_imc_sleep(void)
617 {
618 	int timeout = MAX_TIMEOUT;
619 
620 	if (!request_muxed_region(KERNCZ_IMC_IDX, 2, "smbus_kerncz_imc"))
621 		return -EBUSY;
622 
623 	/* clear response register */
624 	piix4_imc_write(0x82, 0x00);
625 	/* request ownership flag */
626 	piix4_imc_write(0x83, 0xB4);
627 	/* kick off IMC Mailbox command 96 */
628 	piix4_imc_write(0x80, 0x96);
629 
630 	while (timeout--) {
631 		if (piix4_imc_read(0x82) == 0xfa) {
632 			release_region(KERNCZ_IMC_IDX, 2);
633 			return 0;
634 		}
635 		usleep_range(1000, 2000);
636 	}
637 
638 	release_region(KERNCZ_IMC_IDX, 2);
639 	return -ETIMEDOUT;
640 }
641 
642 static void piix4_imc_wakeup(void)
643 {
644 	int timeout = MAX_TIMEOUT;
645 
646 	if (!request_muxed_region(KERNCZ_IMC_IDX, 2, "smbus_kerncz_imc"))
647 		return;
648 
649 	/* clear response register */
650 	piix4_imc_write(0x82, 0x00);
651 	/* release ownership flag */
652 	piix4_imc_write(0x83, 0xB5);
653 	/* kick off IMC Mailbox command 96 */
654 	piix4_imc_write(0x80, 0x96);
655 
656 	while (timeout--) {
657 		if (piix4_imc_read(0x82) == 0xfa)
658 			break;
659 		usleep_range(1000, 2000);
660 	}
661 
662 	release_region(KERNCZ_IMC_IDX, 2);
663 }
664 
665 /*
666  * Handles access to multiple SMBus ports on the SB800.
667  * The port is selected by bits 2:1 of the smb_en register (0x2c).
668  * Returns negative errno on error.
669  *
670  * Note: The selected port must be returned to the initial selection to avoid
671  * problems on certain systems.
672  */
673 static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
674 		 unsigned short flags, char read_write,
675 		 u8 command, int size, union i2c_smbus_data *data)
676 {
677 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
678 	unsigned short piix4_smba = adapdata->smba;
679 	int retries = MAX_TIMEOUT;
680 	int smbslvcnt;
681 	u8 smba_en_lo;
682 	u8 port;
683 	int retval;
684 
685 	if (!request_muxed_region(SB800_PIIX4_SMB_IDX, 2, "sb800_piix4_smb"))
686 		return -EBUSY;
687 
688 	/* Request the SMBUS semaphore, avoid conflicts with the IMC */
689 	smbslvcnt  = inb_p(SMBSLVCNT);
690 	do {
691 		outb_p(smbslvcnt | 0x10, SMBSLVCNT);
692 
693 		/* Check the semaphore status */
694 		smbslvcnt  = inb_p(SMBSLVCNT);
695 		if (smbslvcnt & 0x10)
696 			break;
697 
698 		usleep_range(1000, 2000);
699 	} while (--retries);
700 	/* SMBus is still owned by the IMC, we give up */
701 	if (!retries) {
702 		retval = -EBUSY;
703 		goto release;
704 	}
705 
706 	/*
707 	 * Notify the IMC (Integrated Micro Controller) if required.
708 	 * Among other responsibilities, the IMC is in charge of monitoring
709 	 * the System fans and temperature sensors, and act accordingly.
710 	 * All this is done through SMBus and can/will collide
711 	 * with our transactions if they are long (BLOCK_DATA).
712 	 * Therefore we need to request the ownership flag during those
713 	 * transactions.
714 	 */
715 	if ((size == I2C_SMBUS_BLOCK_DATA) && adapdata->notify_imc) {
716 		int ret;
717 
718 		ret = piix4_imc_sleep();
719 		switch (ret) {
720 		case -EBUSY:
721 			dev_warn(&adap->dev,
722 				 "IMC base address index region 0x%x already in use.\n",
723 				 KERNCZ_IMC_IDX);
724 			break;
725 		case -ETIMEDOUT:
726 			dev_warn(&adap->dev,
727 				 "Failed to communicate with the IMC.\n");
728 			break;
729 		default:
730 			break;
731 		}
732 
733 		/* If IMC communication fails do not retry */
734 		if (ret) {
735 			dev_warn(&adap->dev,
736 				 "Continuing without IMC notification.\n");
737 			adapdata->notify_imc = false;
738 		}
739 	}
740 
741 	outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX);
742 	smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
743 
744 	port = adapdata->port;
745 	if ((smba_en_lo & piix4_port_mask_sb800) != port)
746 		outb_p((smba_en_lo & ~piix4_port_mask_sb800) | port,
747 		       SB800_PIIX4_SMB_IDX + 1);
748 
749 	retval = piix4_access(adap, addr, flags, read_write,
750 			      command, size, data);
751 
752 	outb_p(smba_en_lo, SB800_PIIX4_SMB_IDX + 1);
753 
754 	/* Release the semaphore */
755 	outb_p(smbslvcnt | 0x20, SMBSLVCNT);
756 
757 	if ((size == I2C_SMBUS_BLOCK_DATA) && adapdata->notify_imc)
758 		piix4_imc_wakeup();
759 
760 release:
761 	release_region(SB800_PIIX4_SMB_IDX, 2);
762 	return retval;
763 }
764 
765 static u32 piix4_func(struct i2c_adapter *adapter)
766 {
767 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
768 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
769 	    I2C_FUNC_SMBUS_BLOCK_DATA;
770 }
771 
772 static const struct i2c_algorithm smbus_algorithm = {
773 	.smbus_xfer	= piix4_access,
774 	.functionality	= piix4_func,
775 };
776 
777 static const struct i2c_algorithm piix4_smbus_algorithm_sb800 = {
778 	.smbus_xfer	= piix4_access_sb800,
779 	.functionality	= piix4_func,
780 };
781 
782 static const struct pci_device_id piix4_ids[] = {
783 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
784 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3) },
785 	{ PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_SLC90E66_3) },
786 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP200_SMBUS) },
787 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP300_SMBUS) },
788 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS) },
789 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS) },
790 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) },
791 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) },
792 	{ PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) },
793 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
794 		     PCI_DEVICE_ID_SERVERWORKS_OSB4) },
795 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
796 		     PCI_DEVICE_ID_SERVERWORKS_CSB5) },
797 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
798 		     PCI_DEVICE_ID_SERVERWORKS_CSB6) },
799 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
800 		     PCI_DEVICE_ID_SERVERWORKS_HT1000SB) },
801 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
802 		     PCI_DEVICE_ID_SERVERWORKS_HT1100LD) },
803 	{ 0, }
804 };
805 
806 MODULE_DEVICE_TABLE (pci, piix4_ids);
807 
808 static struct i2c_adapter *piix4_main_adapters[PIIX4_MAX_ADAPTERS];
809 static struct i2c_adapter *piix4_aux_adapter;
810 static int piix4_adapter_count;
811 
812 static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
813 			     bool sb800_main, u8 port, bool notify_imc,
814 			     u8 hw_port_nr, const char *name,
815 			     struct i2c_adapter **padap)
816 {
817 	struct i2c_adapter *adap;
818 	struct i2c_piix4_adapdata *adapdata;
819 	int retval;
820 
821 	adap = kzalloc(sizeof(*adap), GFP_KERNEL);
822 	if (adap == NULL) {
823 		release_region(smba, SMBIOSIZE);
824 		return -ENOMEM;
825 	}
826 
827 	adap->owner = THIS_MODULE;
828 	adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
829 	adap->algo = sb800_main ? &piix4_smbus_algorithm_sb800
830 				: &smbus_algorithm;
831 
832 	adapdata = kzalloc(sizeof(*adapdata), GFP_KERNEL);
833 	if (adapdata == NULL) {
834 		kfree(adap);
835 		release_region(smba, SMBIOSIZE);
836 		return -ENOMEM;
837 	}
838 
839 	adapdata->smba = smba;
840 	adapdata->sb800_main = sb800_main;
841 	adapdata->port = port << piix4_port_shift_sb800;
842 	adapdata->notify_imc = notify_imc;
843 
844 	/* set up the sysfs linkage to our parent device */
845 	adap->dev.parent = &dev->dev;
846 
847 	if (has_acpi_companion(&dev->dev)) {
848 		acpi_preset_companion(&adap->dev,
849 				      ACPI_COMPANION(&dev->dev),
850 				      hw_port_nr);
851 	}
852 
853 	snprintf(adap->name, sizeof(adap->name),
854 		"SMBus PIIX4 adapter%s at %04x", name, smba);
855 
856 	i2c_set_adapdata(adap, adapdata);
857 
858 	retval = i2c_add_adapter(adap);
859 	if (retval) {
860 		kfree(adapdata);
861 		kfree(adap);
862 		release_region(smba, SMBIOSIZE);
863 		return retval;
864 	}
865 
866 	*padap = adap;
867 	return 0;
868 }
869 
870 static int piix4_add_adapters_sb800(struct pci_dev *dev, unsigned short smba,
871 				    bool notify_imc)
872 {
873 	struct i2c_piix4_adapdata *adapdata;
874 	int port;
875 	int retval;
876 
877 	if (dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS ||
878 	    (dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
879 	     dev->revision >= 0x1F)) {
880 		piix4_adapter_count = HUDSON2_MAIN_PORTS;
881 	} else {
882 		piix4_adapter_count = PIIX4_MAX_ADAPTERS;
883 	}
884 
885 	for (port = 0; port < piix4_adapter_count; port++) {
886 		u8 hw_port_nr = port == 0 ? 0 : port + 1;
887 
888 		retval = piix4_add_adapter(dev, smba, true, port, notify_imc,
889 					   hw_port_nr,
890 					   piix4_main_port_names_sb800[port],
891 					   &piix4_main_adapters[port]);
892 		if (retval < 0)
893 			goto error;
894 	}
895 
896 	return retval;
897 
898 error:
899 	dev_err(&dev->dev,
900 		"Error setting up SB800 adapters. Unregistering!\n");
901 	while (--port >= 0) {
902 		adapdata = i2c_get_adapdata(piix4_main_adapters[port]);
903 		if (adapdata->smba) {
904 			i2c_del_adapter(piix4_main_adapters[port]);
905 			kfree(adapdata);
906 			kfree(piix4_main_adapters[port]);
907 			piix4_main_adapters[port] = NULL;
908 		}
909 	}
910 
911 	return retval;
912 }
913 
914 static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
915 {
916 	int retval;
917 	bool is_sb800 = false;
918 
919 	if ((dev->vendor == PCI_VENDOR_ID_ATI &&
920 	     dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
921 	     dev->revision >= 0x40) ||
922 	    dev->vendor == PCI_VENDOR_ID_AMD ||
923 	    dev->vendor == PCI_VENDOR_ID_HYGON) {
924 		bool notify_imc = false;
925 		is_sb800 = true;
926 
927 		if ((dev->vendor == PCI_VENDOR_ID_AMD ||
928 		     dev->vendor == PCI_VENDOR_ID_HYGON) &&
929 		    dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) {
930 			u8 imc;
931 
932 			/*
933 			 * Detect if IMC is active or not, this method is
934 			 * described on coreboot's AMD IMC notes
935 			 */
936 			pci_bus_read_config_byte(dev->bus, PCI_DEVFN(0x14, 3),
937 						 0x40, &imc);
938 			if (imc & 0x80)
939 				notify_imc = true;
940 		}
941 
942 		/* base address location etc changed in SB800 */
943 		retval = piix4_setup_sb800(dev, id, 0);
944 		if (retval < 0)
945 			return retval;
946 
947 		/*
948 		 * Try to register multiplexed main SMBus adapter,
949 		 * give up if we can't
950 		 */
951 		retval = piix4_add_adapters_sb800(dev, retval, notify_imc);
952 		if (retval < 0)
953 			return retval;
954 	} else {
955 		retval = piix4_setup(dev, id);
956 		if (retval < 0)
957 			return retval;
958 
959 		/* Try to register main SMBus adapter, give up if we can't */
960 		retval = piix4_add_adapter(dev, retval, false, 0, false, 0,
961 					   "", &piix4_main_adapters[0]);
962 		if (retval < 0)
963 			return retval;
964 	}
965 
966 	/* Check for auxiliary SMBus on some AMD chipsets */
967 	retval = -ENODEV;
968 
969 	if (dev->vendor == PCI_VENDOR_ID_ATI &&
970 	    dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS) {
971 		if (dev->revision < 0x40) {
972 			retval = piix4_setup_aux(dev, id, 0x58);
973 		} else {
974 			/* SB800 added aux bus too */
975 			retval = piix4_setup_sb800(dev, id, 1);
976 		}
977 	}
978 
979 	if (dev->vendor == PCI_VENDOR_ID_AMD &&
980 	    dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) {
981 		retval = piix4_setup_sb800(dev, id, 1);
982 	}
983 
984 	if (retval > 0) {
985 		/* Try to add the aux adapter if it exists,
986 		 * piix4_add_adapter will clean up if this fails */
987 		piix4_add_adapter(dev, retval, false, 0, false, 1,
988 				  is_sb800 ? piix4_aux_port_name_sb800 : "",
989 				  &piix4_aux_adapter);
990 	}
991 
992 	return 0;
993 }
994 
995 static void piix4_adap_remove(struct i2c_adapter *adap)
996 {
997 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
998 
999 	if (adapdata->smba) {
1000 		i2c_del_adapter(adap);
1001 		if (adapdata->port == (0 << piix4_port_shift_sb800))
1002 			release_region(adapdata->smba, SMBIOSIZE);
1003 		kfree(adapdata);
1004 		kfree(adap);
1005 	}
1006 }
1007 
1008 static void piix4_remove(struct pci_dev *dev)
1009 {
1010 	int port = piix4_adapter_count;
1011 
1012 	while (--port >= 0) {
1013 		if (piix4_main_adapters[port]) {
1014 			piix4_adap_remove(piix4_main_adapters[port]);
1015 			piix4_main_adapters[port] = NULL;
1016 		}
1017 	}
1018 
1019 	if (piix4_aux_adapter) {
1020 		piix4_adap_remove(piix4_aux_adapter);
1021 		piix4_aux_adapter = NULL;
1022 	}
1023 }
1024 
1025 static struct pci_driver piix4_driver = {
1026 	.name		= "piix4_smbus",
1027 	.id_table	= piix4_ids,
1028 	.probe		= piix4_probe,
1029 	.remove		= piix4_remove,
1030 };
1031 
1032 module_pci_driver(piix4_driver);
1033 
1034 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
1035 		"Philip Edelbrock <phil@netroedge.com>");
1036 MODULE_DESCRIPTION("PIIX4 SMBus driver");
1037 MODULE_LICENSE("GPL");
1038