xref: /linux/drivers/i2c/busses/i2c-viapro.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2     Copyright (c) 1998 - 2002  Frodo Looijaard <frodol@dds.nl>,
3     Philip Edelbrock <phil@netroedge.com>, Kyösti Mälkki <kmalkki@cc.hut.fi>,
4     Mark D. Studebaker <mdsxyz123@yahoo.com>
5     Copyright (C) 2005 - 2008  Jean Delvare <khali@linux-fr.org>
6 
7     This program is free software; you can redistribute it and/or modify
8     it under the terms of the GNU General Public License as published by
9     the Free Software Foundation; either version 2 of the License, or
10     (at your option) any later version.
11 
12     This program is distributed in the hope that it will be useful,
13     but WITHOUT ANY WARRANTY; without even the implied warranty of
14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15     GNU General Public License for more details.
16 
17     You should have received a copy of the GNU General Public License
18     along with this program; if not, write to the Free Software
19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21 
22 /*
23    Supports the following VIA south bridges:
24 
25    Chip name          PCI ID  REV     I2C block
26    VT82C596A          0x3050             no
27    VT82C596B          0x3051             no
28    VT82C686A          0x3057  0x30       no
29    VT82C686B          0x3057  0x40       yes
30    VT8231             0x8235             no?
31    VT8233             0x3074             yes
32    VT8233A            0x3147             yes?
33    VT8235             0x3177             yes
34    VT8237R            0x3227             yes
35    VT8237A            0x3337             yes
36    VT8237S            0x3372             yes
37    VT8251             0x3287             yes
38    CX700              0x8324             yes
39    VX800/VX820        0x8353             yes
40    VX855/VX875        0x8409             yes
41 
42    Note: we assume there can only be one device, with one SMBus interface.
43 */
44 
45 #include <linux/module.h>
46 #include <linux/delay.h>
47 #include <linux/pci.h>
48 #include <linux/kernel.h>
49 #include <linux/stddef.h>
50 #include <linux/ioport.h>
51 #include <linux/i2c.h>
52 #include <linux/init.h>
53 #include <linux/acpi.h>
54 #include <linux/io.h>
55 
56 static struct pci_dev *vt596_pdev;
57 
58 #define SMBBA1		0x90
59 #define SMBBA2		0x80
60 #define SMBBA3		0xD0
61 
62 /* SMBus address offsets */
63 static unsigned short vt596_smba;
64 #define SMBHSTSTS	(vt596_smba + 0)
65 #define SMBHSTCNT	(vt596_smba + 2)
66 #define SMBHSTCMD	(vt596_smba + 3)
67 #define SMBHSTADD	(vt596_smba + 4)
68 #define SMBHSTDAT0	(vt596_smba + 5)
69 #define SMBHSTDAT1	(vt596_smba + 6)
70 #define SMBBLKDAT	(vt596_smba + 7)
71 
72 /* PCI Address Constants */
73 
74 /* SMBus data in configuration space can be found in two places,
75    We try to select the better one */
76 
77 static unsigned short SMBHSTCFG = 0xD2;
78 
79 /* Other settings */
80 #define MAX_TIMEOUT	500
81 
82 /* VT82C596 constants */
83 #define VT596_QUICK		0x00
84 #define VT596_BYTE		0x04
85 #define VT596_BYTE_DATA		0x08
86 #define VT596_WORD_DATA		0x0C
87 #define VT596_PROC_CALL		0x10
88 #define VT596_BLOCK_DATA	0x14
89 #define VT596_I2C_BLOCK_DATA	0x34
90 
91 
92 /* If force is set to anything different from 0, we forcibly enable the
93    VT596. DANGEROUS! */
94 static int force;
95 module_param(force, bool, 0);
96 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
97 
98 /* If force_addr is set to anything different from 0, we forcibly enable
99    the VT596 at the given address. VERY DANGEROUS! */
100 static u16 force_addr;
101 module_param(force_addr, ushort, 0);
102 MODULE_PARM_DESC(force_addr,
103 		 "Forcibly enable the SMBus at the given address. "
104 		 "EXTREMELY DANGEROUS!");
105 
106 
107 static struct pci_driver vt596_driver;
108 static struct i2c_adapter vt596_adapter;
109 
110 #define FEATURE_I2CBLOCK	(1<<0)
111 static unsigned int vt596_features;
112 
113 #ifdef DEBUG
114 static void vt596_dump_regs(const char *msg, u8 size)
115 {
116 	dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x "
117 		"DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT),
118 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
119 		inb_p(SMBHSTDAT1));
120 
121 	if (size == VT596_BLOCK_DATA
122 	 || size == VT596_I2C_BLOCK_DATA) {
123 		int i;
124 
125 		dev_dbg(&vt596_adapter.dev, "BLK=");
126 		for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++)
127 			printk("%02x,", inb_p(SMBBLKDAT));
128 		printk("\n");
129 		dev_dbg(&vt596_adapter.dev, "    ");
130 		for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++)
131 			printk("%02x,", inb_p(SMBBLKDAT));
132 		printk("%02x\n", inb_p(SMBBLKDAT));
133 	}
134 }
135 #else
136 static inline void vt596_dump_regs(const char *msg, u8 size) { }
137 #endif
138 
139 /* Return -1 on error, 0 on success */
140 static int vt596_transaction(u8 size)
141 {
142 	int temp;
143 	int result = 0;
144 	int timeout = 0;
145 
146 	vt596_dump_regs("Transaction (pre)", size);
147 
148 	/* Make sure the SMBus host is ready to start transmitting */
149 	if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
150 		dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
151 			"Resetting...\n", temp);
152 
153 		outb_p(temp, SMBHSTSTS);
154 		if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
155 			dev_err(&vt596_adapter.dev, "SMBus reset failed! "
156 				"(0x%02x)\n", temp);
157 			return -EBUSY;
158 		}
159 	}
160 
161 	/* Start the transaction by setting bit 6 */
162 	outb_p(0x40 | size, SMBHSTCNT);
163 
164 	/* We will always wait for a fraction of a second */
165 	do {
166 		msleep(1);
167 		temp = inb_p(SMBHSTSTS);
168 	} while ((temp & 0x01) && (++timeout < MAX_TIMEOUT));
169 
170 	/* If the SMBus is still busy, we give up */
171 	if (timeout == MAX_TIMEOUT) {
172 		result = -ETIMEDOUT;
173 		dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
174 	}
175 
176 	if (temp & 0x10) {
177 		result = -EIO;
178 		dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
179 			size);
180 	}
181 
182 	if (temp & 0x08) {
183 		result = -EIO;
184 		dev_err(&vt596_adapter.dev, "SMBus collision!\n");
185 	}
186 
187 	if (temp & 0x04) {
188 		result = -ENXIO;
189 		dev_dbg(&vt596_adapter.dev, "No response\n");
190 	}
191 
192 	/* Resetting status register */
193 	if (temp & 0x1F)
194 		outb_p(temp, SMBHSTSTS);
195 
196 	vt596_dump_regs("Transaction (post)", size);
197 
198 	return result;
199 }
200 
201 /* Return negative errno on error, 0 on success */
202 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
203 		unsigned short flags, char read_write, u8 command,
204 		int size, union i2c_smbus_data *data)
205 {
206 	int i;
207 	int status;
208 
209 	switch (size) {
210 	case I2C_SMBUS_QUICK:
211 		size = VT596_QUICK;
212 		break;
213 	case I2C_SMBUS_BYTE:
214 		if (read_write == I2C_SMBUS_WRITE)
215 			outb_p(command, SMBHSTCMD);
216 		size = VT596_BYTE;
217 		break;
218 	case I2C_SMBUS_BYTE_DATA:
219 		outb_p(command, SMBHSTCMD);
220 		if (read_write == I2C_SMBUS_WRITE)
221 			outb_p(data->byte, SMBHSTDAT0);
222 		size = VT596_BYTE_DATA;
223 		break;
224 	case I2C_SMBUS_WORD_DATA:
225 		outb_p(command, SMBHSTCMD);
226 		if (read_write == I2C_SMBUS_WRITE) {
227 			outb_p(data->word & 0xff, SMBHSTDAT0);
228 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
229 		}
230 		size = VT596_WORD_DATA;
231 		break;
232 	case I2C_SMBUS_PROC_CALL:
233 		outb_p(command, SMBHSTCMD);
234 		outb_p(data->word & 0xff, SMBHSTDAT0);
235 		outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
236 		size = VT596_PROC_CALL;
237 		break;
238 	case I2C_SMBUS_I2C_BLOCK_DATA:
239 		if (!(vt596_features & FEATURE_I2CBLOCK))
240 			goto exit_unsupported;
241 		if (read_write == I2C_SMBUS_READ)
242 			outb_p(data->block[0], SMBHSTDAT0);
243 		/* Fall through */
244 	case I2C_SMBUS_BLOCK_DATA:
245 		outb_p(command, SMBHSTCMD);
246 		if (read_write == I2C_SMBUS_WRITE) {
247 			u8 len = data->block[0];
248 			if (len > I2C_SMBUS_BLOCK_MAX)
249 				len = I2C_SMBUS_BLOCK_MAX;
250 			outb_p(len, SMBHSTDAT0);
251 			inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
252 			for (i = 1; i <= len; i++)
253 				outb_p(data->block[i], SMBBLKDAT);
254 		}
255 		size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
256 		       VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
257 		break;
258 	default:
259 		goto exit_unsupported;
260 	}
261 
262 	outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
263 
264 	status = vt596_transaction(size);
265 	if (status)
266 		return status;
267 
268 	if (size == VT596_PROC_CALL)
269 		read_write = I2C_SMBUS_READ;
270 
271 	if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
272 		return 0;
273 
274 	switch (size) {
275 	case VT596_BYTE:
276 	case VT596_BYTE_DATA:
277 		data->byte = inb_p(SMBHSTDAT0);
278 		break;
279 	case VT596_WORD_DATA:
280 	case VT596_PROC_CALL:
281 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
282 		break;
283 	case VT596_I2C_BLOCK_DATA:
284 	case VT596_BLOCK_DATA:
285 		data->block[0] = inb_p(SMBHSTDAT0);
286 		if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
287 			data->block[0] = I2C_SMBUS_BLOCK_MAX;
288 		inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
289 		for (i = 1; i <= data->block[0]; i++)
290 			data->block[i] = inb_p(SMBBLKDAT);
291 		break;
292 	}
293 	return 0;
294 
295 exit_unsupported:
296 	dev_warn(&vt596_adapter.dev, "Unsupported transaction %d\n",
297 		 size);
298 	return -EOPNOTSUPP;
299 }
300 
301 static u32 vt596_func(struct i2c_adapter *adapter)
302 {
303 	u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
304 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
305 	    I2C_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_DATA;
306 
307 	if (vt596_features & FEATURE_I2CBLOCK)
308 		func |= I2C_FUNC_SMBUS_I2C_BLOCK;
309 	return func;
310 }
311 
312 static const struct i2c_algorithm smbus_algorithm = {
313 	.smbus_xfer	= vt596_access,
314 	.functionality	= vt596_func,
315 };
316 
317 static struct i2c_adapter vt596_adapter = {
318 	.owner		= THIS_MODULE,
319 	.class		= I2C_CLASS_HWMON | I2C_CLASS_SPD,
320 	.algo		= &smbus_algorithm,
321 };
322 
323 static int __devinit vt596_probe(struct pci_dev *pdev,
324 				 const struct pci_device_id *id)
325 {
326 	unsigned char temp;
327 	int error = -ENODEV;
328 
329 	/* Determine the address of the SMBus areas */
330 	if (force_addr) {
331 		vt596_smba = force_addr & 0xfff0;
332 		force = 0;
333 		goto found;
334 	}
335 
336 	if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
337 	    !(vt596_smba & 0x0001)) {
338 		/* try 2nd address and config reg. for 596 */
339 		if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
340 		    !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
341 		    (vt596_smba & 0x0001)) {
342 			SMBHSTCFG = 0x84;
343 		} else {
344 			/* no matches at all */
345 			dev_err(&pdev->dev, "Cannot configure "
346 				"SMBus I/O Base address\n");
347 			return -ENODEV;
348 		}
349 	}
350 
351 	vt596_smba &= 0xfff0;
352 	if (vt596_smba == 0) {
353 		dev_err(&pdev->dev, "SMBus base address "
354 			"uninitialized - upgrade BIOS or use "
355 			"force_addr=0xaddr\n");
356 		return -ENODEV;
357 	}
358 
359 found:
360 	error = acpi_check_region(vt596_smba, 8, vt596_driver.name);
361 	if (error)
362 		return -ENODEV;
363 
364 	if (!request_region(vt596_smba, 8, vt596_driver.name)) {
365 		dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
366 			vt596_smba);
367 		return -ENODEV;
368 	}
369 
370 	pci_read_config_byte(pdev, SMBHSTCFG, &temp);
371 	/* If force_addr is set, we program the new address here. Just to make
372 	   sure, we disable the VT596 first. */
373 	if (force_addr) {
374 		pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
375 		pci_write_config_word(pdev, id->driver_data, vt596_smba);
376 		pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
377 		dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
378 			 "address 0x%04x!\n", vt596_smba);
379 	} else if (!(temp & 0x01)) {
380 		if (force) {
381 			/* NOTE: This assumes I/O space and other allocations
382 			 * WERE done by the Bios!  Don't complain if your
383 			 * hardware does weird things after enabling this.
384 			 * :') Check for Bios updates before resorting to
385 			 * this.
386 			 */
387 			pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
388 			dev_info(&pdev->dev, "Enabling SMBus device\n");
389 		} else {
390 			dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
391 				"controller not enabled! - upgrade BIOS or "
392 				"use force=1\n");
393 			goto release_region;
394 		}
395 	}
396 
397 	dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
398 
399 	switch (pdev->device) {
400 	case PCI_DEVICE_ID_VIA_CX700:
401 	case PCI_DEVICE_ID_VIA_VX800:
402 	case PCI_DEVICE_ID_VIA_VX855:
403 	case PCI_DEVICE_ID_VIA_8251:
404 	case PCI_DEVICE_ID_VIA_8237:
405 	case PCI_DEVICE_ID_VIA_8237A:
406 	case PCI_DEVICE_ID_VIA_8237S:
407 	case PCI_DEVICE_ID_VIA_8235:
408 	case PCI_DEVICE_ID_VIA_8233A:
409 	case PCI_DEVICE_ID_VIA_8233_0:
410 		vt596_features |= FEATURE_I2CBLOCK;
411 		break;
412 	case PCI_DEVICE_ID_VIA_82C686_4:
413 		/* The VT82C686B (rev 0x40) does support I2C block
414 		   transactions, but the VT82C686A (rev 0x30) doesn't */
415 		if (pdev->revision >= 0x40)
416 			vt596_features |= FEATURE_I2CBLOCK;
417 		break;
418 	}
419 
420 	vt596_adapter.dev.parent = &pdev->dev;
421 	snprintf(vt596_adapter.name, sizeof(vt596_adapter.name),
422 		 "SMBus Via Pro adapter at %04x", vt596_smba);
423 
424 	vt596_pdev = pci_dev_get(pdev);
425 	if (i2c_add_adapter(&vt596_adapter)) {
426 		pci_dev_put(vt596_pdev);
427 		vt596_pdev = NULL;
428 	}
429 
430 	/* Always return failure here.  This is to allow other drivers to bind
431 	 * to this pci device.  We don't really want to have control over the
432 	 * pci device, we only wanted to read as few register values from it.
433 	 */
434 	return -ENODEV;
435 
436 release_region:
437 	release_region(vt596_smba, 8);
438 	return error;
439 }
440 
441 static const struct pci_device_id vt596_ids[] = {
442 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
443 	  .driver_data = SMBBA1 },
444 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
445 	  .driver_data = SMBBA1 },
446 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
447 	  .driver_data = SMBBA1 },
448 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
449 	  .driver_data = SMBBA3 },
450 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
451 	  .driver_data = SMBBA3 },
452 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
453 	  .driver_data = SMBBA3 },
454 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
455 	  .driver_data = SMBBA3 },
456 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237A),
457 	  .driver_data = SMBBA3 },
458 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237S),
459 	  .driver_data = SMBBA3 },
460 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
461 	  .driver_data = SMBBA1 },
462 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8251),
463 	  .driver_data = SMBBA3 },
464 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700),
465 	  .driver_data = SMBBA3 },
466 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX800),
467 	  .driver_data = SMBBA3 },
468 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855),
469 	  .driver_data = SMBBA3 },
470 	{ 0, }
471 };
472 
473 MODULE_DEVICE_TABLE(pci, vt596_ids);
474 
475 static struct pci_driver vt596_driver = {
476 	.name		= "vt596_smbus",
477 	.id_table	= vt596_ids,
478 	.probe		= vt596_probe,
479 };
480 
481 static int __init i2c_vt596_init(void)
482 {
483 	return pci_register_driver(&vt596_driver);
484 }
485 
486 
487 static void __exit i2c_vt596_exit(void)
488 {
489 	pci_unregister_driver(&vt596_driver);
490 	if (vt596_pdev != NULL) {
491 		i2c_del_adapter(&vt596_adapter);
492 		release_region(vt596_smba, 8);
493 		pci_dev_put(vt596_pdev);
494 		vt596_pdev = NULL;
495 	}
496 }
497 
498 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, "
499 	      "Mark D. Studebaker <mdsxyz123@yahoo.com> and "
500 	      "Jean Delvare <khali@linux-fr.org>");
501 MODULE_DESCRIPTION("vt82c596 SMBus driver");
502 MODULE_LICENSE("GPL");
503 
504 module_init(i2c_vt596_init);
505 module_exit(i2c_vt596_exit);
506